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Fujimura S, Yamanaka Y, Kan I, Nagao M, Otani K, Karagiozov K, Fukudome K, Ishibashi T, Takao H, Motosuke M, Yamamoto M, Murayama Y. Experimental study using phantom models of cerebral aneurysms and 4D-DSA to measure blood flow on 3D-color-coded images. Technol Health Care 2024:THC231906. [PMID: 38968064 DOI: 10.3233/thc-231906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/07/2024]
Abstract
BACKGROUND The current 3D-iFlow application can only measure the arrival time of contrast media through intensity values. If the flow rate could be estimated by 3D-iFlow, patient-specific hemodynamics could be determined within the scope of normal diagnostic management, eliminating the need for additional resources for blood flow rate estimation. OBJECTIVE The aim of this study is to develop and validate a method for measuring the flow rate by data obtained from 3D-iFlow images - a prototype application in Four-dimensional digital subtraction angiography (4D-DSA). METHODS Using phantom model and experimental circuit with circulating glycerin solution, an equation for the relationship between contrast media intensity and flow rate was developed. Applying the equation to the aneurysm phantom models, the derived flow rate was evaluated. RESULTS The average errors between the derived flow rate and setting flow rate became larger when the glycerin flow and the X-rays from the X-ray tube of the angiography system were parallel to each other or when the measurement point included overlaps with other contrast enhanced areas. CONCLUSION Although the error increases dependent on the imaging direction and overlap of contrast enhanced area, the developed equation can estimate the flow rate using the image intensity value measured on 3D-iFlow based on 4D-DSA.
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Affiliation(s)
- Soichiro Fujimura
- Department of Mechanical Engineering, Tokyo University of Science, Tokyo, Japan
- Division of Innovation for Medical Information Technology, The Jikei University School of Medicine, Tokyo, Japan
- Department of Mechanical Engineering, Tokyo University of Science, Tokyo, Japan
| | - Yuma Yamanaka
- Division of Innovation for Medical Information Technology, The Jikei University School of Medicine, Tokyo, Japan
- Graduate School of Mechanical Engineering, Tokyo University of Science, Tokyo, Japan
- Department of Mechanical Engineering, Tokyo University of Science, Tokyo, Japan
| | - Issei Kan
- Department of Neurosurgery, The Jikei University School of Medicine, Tokyo, Japan
| | - Masahiro Nagao
- Graduate School of Mechanical Engineering, Tokyo University of Science, Tokyo, Japan
| | - Katharina Otani
- Department of Neurosurgery, The Jikei University School of Medicine, Tokyo, Japan
- Siemens Healthcare K.K., Tokyo, Japan
| | - Kostadin Karagiozov
- Department of Neurosurgery, The Jikei University School of Medicine, Tokyo, Japan
| | - Koji Fukudome
- Department of Mechanical Engineering, Kanazawa Institute of Technology, Ishikawa, Japan
| | - Toshihiro Ishibashi
- Department of Neurosurgery, The Jikei University School of Medicine, Tokyo, Japan
| | - Hiroyuki Takao
- Division of Innovation for Medical Information Technology, The Jikei University School of Medicine, Tokyo, Japan
- Department of Neurosurgery, The Jikei University School of Medicine, Tokyo, Japan
| | - Masahiro Motosuke
- Department of Mechanical Engineering, Tokyo University of Science, Tokyo, Japan
| | - Makoto Yamamoto
- Department of Mechanical Engineering, Tokyo University of Science, Tokyo, Japan
| | - Yuichi Murayama
- Department of Neurosurgery, The Jikei University School of Medicine, Tokyo, Japan
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Huang K, Yao W, Zha M, Qin S, Li Y, Xu Y, Liu R, Ye R, Han Y, Zhu W, Teng Z, Du J, Liu X. Angiography-based hemodynamic features predict recurrent ischemic events after angioplasty and stenting of intracranial vertebrobasilar atherosclerotic stenosis. Eur Radiol 2024; 34:2352-2363. [PMID: 37723287 PMCID: PMC10957605 DOI: 10.1007/s00330-023-10209-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 07/05/2023] [Accepted: 07/20/2023] [Indexed: 09/20/2023]
Abstract
OBJECTIVES To assess the predictive value of hemodynamic features for stroke relapse in patients with intracranial vertebrobasilar atherosclerotic stenosis treated with percutaneous transluminal angioplasty and stenting (PTAS) using quantitative digital subtraction angiography (q-DSA). METHODS In this retrospective longitudinal study, patients with intracranial vertebrobasilar atherosclerotic stenosis and who underwent PTAS treatment between January 2012 and May 2020 were enrolled. The q-DSA assessment was performed before and after PTAS. ROIs 1-4 were placed along the vertebral artery, proximal and distal basilar artery, and posterior cerebral artery; ROIs 5-8 were in 5 mm and 10 mm proximal and distal to the lesion, respectively. Relative time to peak (rTTP) was defined as the difference in TTP between ROIs. Cox regression analyses were performed to determine risk factors for recurrent stroke. RESULTS A total of 137 patients (mean age, 62 years ± 10 [standard deviation], 83.2% males) were included, and 26 (19.0%) patients had stroke relapse during follow-up (median time of 42.6 months [interquartile range, 19.7-60.7]). Preprocedural rTTP4-1 (adjusted hazard ratio (HR) = 2.270; 95% CI 1.371-3.758; p = 0.001) and preprocedural rTTP8-5 (adjusted HR = 0.240; 95% CI 0.088-0.658; p = 0.006) were independently associated with the recurrent stroke. These hemodynamic parameters provided an incremental prognostic value for stroke relapse (AUC, 0.817 [0.704-0.931]; the net reclassification index, 0.431 [0.057-0.625]; and the integrated discrimination index, 0.140 [0.035-0.292]). CONCLUSIONS In patients with intracranial vertebrobasilar atherosclerosis treated with PTAS, preprocedural prolonged TTP of the target vessel and shortened trans-stenotic TTP difference were associated with stroke relapse. Q-DSA-defined hemodynamic parameters provided incremental predictive value over conventional parameters for stroke recurrence. CLINICAL RELEVANCE STATEMENT Quantitative DSA analysis enables intuitive observation and semi-quantitative evaluation of peri-therapeutic cerebral blood flow. More importantly, quantitative DSA-defined hemodynamic parameters have the potential for risk stratification of patients with intracranial atherosclerotic stenosis. KEY POINTS Semi-quantitative angiography-based parameters can reflect pre- and postprocedural subtle changes in blood flow in patients with intracranial atherosclerotic stenosis. Although angioplasty procedures can significantly improve blood flow status, patients with more restricted baseline blood flow still show a higher risk of stroke recurrence. Angiography-based hemodynamic features possess prognostic value and can serve as clinical markers to assess stroke risk of patients with intracranial atherosclerotic stenosis.
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Affiliation(s)
- Kangmo Huang
- Department of Neurology, Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Weihe Yao
- Department of Neurology, Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Mingming Zha
- Department of Neurology, Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Shanmei Qin
- Department of Neurology, Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Yingle Li
- Department of Neurology, Jinling Hospital, The First School of Clinical Medicine, Southern Medical University, Nanjing, China
| | - Yan Xu
- Neusoft Medical Systems Co., Ltd., Shenyang, China
| | - Rui Liu
- Department of Neurology, Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Ruidong Ye
- Department of Neurology, Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Yunfei Han
- Department of Neurology, Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Wusheng Zhu
- Department of Neurology, Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Zhongzhao Teng
- Department of Radiology, University of Cambridge, Cambridge, UK
| | - Juan Du
- Department of Neurology, Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, China.
| | - Xinfeng Liu
- Department of Neurology, Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, China.
- Department of Neurology, Jinling Hospital, The First School of Clinical Medicine, Southern Medical University, Nanjing, China.
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Shields A, Williams K, Bhurwani MMS, Nagesh SVS, Chivukula VK, Bednarek DR, Rudin S, Davies J, Siddiqui AH, Ionita CN. Enhancing cerebral vasculature analysis with pathlength-corrected 2D angiographic parametric imaging: A feasibility study. Med Phys 2024; 51:2633-2647. [PMID: 37864843 PMCID: PMC10994741 DOI: 10.1002/mp.16808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Revised: 09/09/2023] [Accepted: 09/27/2023] [Indexed: 10/23/2023] Open
Abstract
BACKGROUND 2D angiographic parametric imaging (API) quantitatively extracts imaging biomarkers related to contrast flow and is conventionally applied to 2D digitally subtracted angiograms (DSA's). In the interventional suite, API is typically performed using 1-2 projection views and is limited by vessel overlap, foreshortening, and depth-integration of contrast motion. PURPOSE This work explores the use of a pathlength-correction metric to overcome the limitations of 2D-API: the primary objective was to study the effect of converting 3D contrast flow to projected contrast flow using a simulated angiographic framework created with computational fluid dynamics (CFD) simulations, thereby removing acquisition variability. METHODS The pathlength-correction framework was applied to in-silico angiograms, generating a reference (i.e., ground-truth) volumetric contrast distribution in four patient-specific intracranial aneurysm geometries. Biplane projections of contrast flow were created from the reference volumetric contrast distributions, assuming a cone-beam geometry. A Parker-weighted reconstruction was performed to obtain a binary representation of the vessel structure in 3D. Standard ray tracing techniques were then used to track the intersection of a ray from the focal spot with each voxel of the reconstructed vessel wall to a pixel in the detector plane. The lengths of each ray through the 3D vessel lumen were then projected along each ray-path to create a pathlength-correction map, where the pixel intensity in the detector plane corresponds to the vessel width along each source-detector ray. By dividing the projection sequences with this correction map, 2D pathlength-corrected in-silico angiograms were obtained. We then performed voxel-wise (3D) API on the ground-truth contrast distribution and compared it to pixel-wise (2D) API, both with and without pathlength correction for each biplane view. The percentage difference (PD) between the resultant API biomarkers in each dataset were calculated within the aneurysm region of interest (ROI). RESULTS Intensity-based API parameters, such as the area under the curve (AUC) and peak height (PH), exhibited notable changes in magnitude and spatial distribution following pathlength correction: these now accurately represent conservation of mass of injected contrast media within each arterial geometry and accurately reflect regions of stagnation and recirculation in each aneurysm ROI. Improved agreement was observed between these biomarkers in the pathlength-corrected biplane maps: the maximum PD within the aneurysm ROI is 3.3% with pathlength correction and 47.7% without pathlength correction. As expected, improved agreement with ROI-averaged ground-truth 3D counterparts was observed for all aneurysm geometries, particularly large aneurysms: the maximum PD for both AUC and PH was 5.8%. Temporal parameters (mean transit time, MTT, time-to-peak, TTP, time-to-arrival, TTA) remained unaffected after pathlength correction. CONCLUSIONS This study indicates that the values of intensity-based API parameters obtained with conventional 2D-API, without pathlength correction, are highly dependent on the projection orientation, and uncorrected API should be avoided for hemodynamic analysis. The proposed metric can standardize 2D API-derived biomarkers independent of projection orientation, potentially improving the diagnostic value of all acquired 2D-DSA's. Integration of a pathlength correction map into the imaging process can allow for improved interpretation of biomarkers in 2D space, which may lead to improved diagnostic accuracy during procedures involving the cerebral vasculature.
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Affiliation(s)
- Allison Shields
- Medical Physics Program, University at Buffalo, Buffalo, New York, USA 14203
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, New York, USA 14203
| | - Kyle Williams
- Medical Physics Program, University at Buffalo, Buffalo, New York, USA 14203
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, New York, USA 14203
| | | | - Swetadri Vasan Setlur Nagesh
- Medical Physics Program, University at Buffalo, Buffalo, New York, USA 14203
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, New York, USA 14203
| | - Venkat Keshav Chivukula
- Department of Biomedical Engineering, Florida Institute of Technology, Melbourne, Florida, USA 32901
| | - Daniel R. Bednarek
- Medical Physics Program, University at Buffalo, Buffalo, New York, USA 14203
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, New York, USA 14203
| | - Stephen Rudin
- Medical Physics Program, University at Buffalo, Buffalo, New York, USA 14203
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, New York, USA 14203
| | - Jason Davies
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, New York, USA 14203
- Department of Neurosurgery, University at Buffalo, Buffalo, New York, USA 14203
| | - Adnan H Siddiqui
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, New York, USA 14203
- Department of Neurosurgery, University at Buffalo, Buffalo, New York, USA 14203
| | - Ciprian N. Ionita
- Medical Physics Program, University at Buffalo, Buffalo, New York, USA 14203
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, New York, USA 14203
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Whitehead JF, Hoffman CA, Wagner MG, Minesinger GM, Nikolau EP, Laeseke PF, Speidel MA. Interleaved x-ray imaging: A method for simultaneous acquisition of quantitative and diagnostic digital subtraction angiography. Med Phys 2024; 51:2468-2478. [PMID: 37856176 PMCID: PMC10994749 DOI: 10.1002/mp.16794] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 09/26/2023] [Accepted: 09/27/2023] [Indexed: 10/20/2023] Open
Abstract
BACKGROUND Flow altering angiographic procedures suffer from ill-defined, qualitative endpoints. Quantitative digital subtraction angiography (qDSA) is an emerging technology that aims to address this issue by providing intra-procedural blood velocity measurements from time-resolved, 2D angiograms. To date, qDSA has used 30 frame/s DSA imaging, which is associated with high radiation dose rate compared to clinical diagnostic DSA (up to 4 frame/s). PURPOSE The purpose of this study is to demonstrate an interleaved x-ray imaging method which decreases the radiation dose rate associated with high frame rate qDSA while simultaneously providing low frame rate diagnostic DSA images, enabling the acquisition of both datasets in a single image sequence with a single injection of contrast agent. METHODS Interleaved x-ray imaging combines low radiation dose image frames acquired at a high rate with high radiation dose image frames acquired at a low rate. The feasibility of this approach was evaluated on an x-ray system equipped with research prototype software for x-ray tube control. qDSA blood velocity quantification was evaluated in a flow phantom study for two lower dose interleaving protocols (LD1:3.7 ± 0.02 mGy / s $3.7 \pm 0.02\ {\mathrm{mGy}}/{\mathrm{s}}$ and LD2:1.7 ± 0.04 mGy / s $1.7 \pm 0.04{\mathrm{\ mGy}}/{\mathrm{s}}$ ) and one conventional (full dose) protocol (11.4 ± 0.04 mGy / s ) $11.4 \pm 0.04{\mathrm{\ mGy}}/{\mathrm{s}})$ . Dose was measured at the interventional reference point. Fluid velocities ranging from 24 to 45 cm/s were investigated. Gold standard velocities were measured using an ultrasound flow probe. Linear regression and Bland-Altman analysis were used to compare ultrasound and qDSA. RESULTS The LD1 and LD2 interleaved protocols resulted in dose rate reductions of -67.7% and -85.5%, compared to the full dose qDSA scan. For the full dose protocol, the Bland-Altman limits of agreement (LOA) between qDSA and ultrasound velocities were [0.7, 6.7] cm/s with a mean difference of 3.7 cm/s. The LD1 interleaved protocol results were similar (LOA: [0.3, 6.9] cm/s, bias: 3.6 cm/s). The LD2 interleaved protocol resulted in slightly larger LOA: [-2.5, 5.5] cm/s with a decrease in the bias: 1.5 cm/s. Linear regression analysis showed a strong correlation between ultrasound and qDSA derived velocities using the LD1 protocol, with aR 2 ${R}^2$ of0.96 $0.96$ , a slope of1.05 $1.05$ and an offset of1.9 $1.9$ cm/s. Similar values were also found for the LD2 protocol, with aR 2 ${R}^2$ of0.93 $0.93$ , a slope of0.98 $0.98$ and an offset of2.0 $2.0$ cm/s. CONCLUSIONS The interleaved method enables simultaneous acquisition of low-dose high-rate images for intra-procedural blood velocity quantification (qDSA) and high-dose low-rate images for vessel morphology evaluation (diagnostic DSA).
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Affiliation(s)
- Joseph F. Whitehead
- Department of Medical Physics, University of Wisconsin - Madison, Madison, Wisconsin, 53705, United States of America
| | - Carson A. Hoffman
- Department of Radiology, University of Wisconsin - Madison, Madison, Wisconsin, 53792, United States of America
| | - Martin G. Wagner
- Department of Radiology, University of Wisconsin - Madison, Madison, Wisconsin, 53792, United States of America
| | - Grace M. Minesinger
- Department of Medical Physics, University of Wisconsin - Madison, Madison, Wisconsin, 53705, United States of America
| | - Ethan P. Nikolau
- Department of Medical Physics, University of Wisconsin - Madison, Madison, Wisconsin, 53705, United States of America
| | - Paul F. Laeseke
- Department of Radiology, University of Wisconsin - Madison, Madison, Wisconsin, 53792, United States of America
| | - Michael A. Speidel
- Department of Medical Physics, University of Wisconsin - Madison, Madison, Wisconsin, 53705, United States of America
- Department of Medicine, University of Wisconsin - Madison, Madison, Wisconsin, 53705, United States of America
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Wagner MG, Whitehead JF, Periyasamy S, Laeseke PF, Speidel MA. Spatiotemporal frequency domain analysis for blood velocity measurement during embolization procedures. Med Phys 2024; 51:1726-1737. [PMID: 37665770 PMCID: PMC10909916 DOI: 10.1002/mp.16715] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 08/22/2023] [Accepted: 08/23/2023] [Indexed: 09/06/2023] Open
Abstract
BACKGROUND Currently, determining procedural endpoints and treatment efficacy of vascular interventions is largely qualitative and relies on subjective visual assessment of digital subtraction angiography (DSA) images leading to large interobserver variabilities and poor reproducibility. Quantitative metrics such as the residual blood velocity in embolized vessel branches could help establish objective and reproducible endpoints. Recently, velocity quantification techniques based on a contrast enhanced X-ray sequence such as qDSA and 4D DSA have been proposed. These techniques must be robust, and, to avoid radiation dose concerns, they should be compatible with low dose per frame image acquisition. PURPOSE To develop and evaluate a technique for robust blood velocity quantification from low dose contrast enhanced X-ray image sequences that leverages the oscillating signal created by pulsatile blood flow. METHODS The proposed spatiotemporal frequency domain (STF) approach quantifies velocities from time attenuation maps (TAMs) representing the oscillating signal over time for all points along a vessel centerline. Due to the time it takes a contrast bolus to travel along the vessel centerline, the resulting TAM resembles a sheared sine wave. The shear angle is related to the velocity and can be determined in the spatiotemporal frequency domain after applying the 2D Fourier transform to the TAM. The approach was evaluated in a straight tube phantom using three different radiation dose levels and compared to ultrasound transit-time-based measurements. The STF velocity results were also compared to previously published approaches for the measurement of blood velocity from contrast enhanced X-ray sequences including shifted least squared (SLS) and phase shift (PHS). Additionally, an in vivo porcine study (n = 8) was performed where increasing amounts of embolic particles were injected into a hepatic or splenic artery with intermittent velocity measurements after each injection to monitor the resulting reduction in velocity. RESULTS At the lowest evaluated dose level (average air kerma rate 1.3 mGy/s at the interventional reference point), the Pearson correlation between ultrasound and STF velocity measurements was99 % $99\%$ . This was significantly higher (p < 0.0001 $p < 0.0001$ ) than corresponding correlation results between ultrasound and the previously published SLS and PHS approaches (91 $\hskip.001pt 91$ and93 % $93\%$ , respectively). In the in vivo study, a reduction in velocity was observed in85.7 % $85.7\%$ of cases after injection of 1 mL,96.4 % $96.4\%$ after 3 mL, and100.0 % $100.0\%$ after 4 mL of embolic particles. CONCLUSIONS The results show good agreement of the spatiotemporal frequency domain approach with ultrasound even in low dose per frame image sequences. Additionally, the in vivo study demonstrates the ability to monitor the physiological changes due to embolization. This could provide quantitative metrics during vascular procedures to establish objective and reproducible endpoints.
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Affiliation(s)
- Martin G Wagner
- Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, USA
| | - Joseph F Whitehead
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, USA
| | - Sarvesh Periyasamy
- Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA
| | - Paul F Laeseke
- Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA
| | - Michael A Speidel
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, USA
- Department of Medicine, University of Wisconsin, Madison, Wisconsin, USA
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Whitehead JF, Periyasamy S, Laeseke PF, Speidel MA, Wagner MG. Motion-compensation approach for quantitative digital subtraction angiography and its effect on in-vivo blood velocity measurement. J Med Imaging (Bellingham) 2024; 11:013501. [PMID: 38188936 PMCID: PMC10765039 DOI: 10.1117/1.jmi.11.1.013501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 11/13/2023] [Accepted: 12/18/2023] [Indexed: 01/09/2024] Open
Abstract
Purpose Quantitative monitoring of flow-altering interventions has been proposed using algorithms that quantify blood velocity from time-resolved two-dimensional angiograms. These algorithms track the movement of contrast oscillations along a vessel centerline. Vessel motion may occur relative to a statically defined vessel centerline, corrupting the blood velocity measurement. We provide a method for motion-compensated blood velocity quantification. Approach The motion-compensation approach utilizes a vessel segmentation algorithm to perform frame-by-frame vessel registration and creates a dynamic vessel centerline that moves with the vasculature. Performance was evaluated in-vivo through comparison with manually annotated centerlines. The method was also compared to a previous uncompensated method using best- and worst-case static centerlines chosen to minimize and maximize centerline placement accuracy. Blood velocities determined through quantitative DSA (qDSA) analysis for each centerline type were compared through linear regression analysis. Results Centerline distance errors were 0.3 ± 0.1 mm relative to gold standard manual annotations. For the uncompensated approach, the best- and worst-case static centerlines had distance errors of 1.1 ± 0.6 and 2.9 ± 1.2 mm , respectively. Linear regression analysis found a high R -squared between qDSA-derived blood velocities using gold standard centerlines and motion-compensated centerlines (R 2 = 0.97 ) with a slope of 1.15 and a small offset of - 0.6 cm / s . The use of static centerlines resulted in low coefficients of determination for the best case (R 2 = 0.35 ) and worst-case (R 2 = 0.20 ) scenarios, with slopes close to zero. Conclusions In-vivo validation of motion-compensated qDSA analysis demonstrated improved velocity quantification accuracy in vessels with motion, addressing an important clinical limitation of the current qDSA algorithm.
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Affiliation(s)
- Joseph F. Whitehead
- University of Wisconsin – Madison, Department of Medical Physics, Madison, Wisconsin, United States
| | - Sarvesh Periyasamy
- University of Wisconsin – Madison, Department of Radiology, Madison, Wisconsin, United States
| | - Paul F. Laeseke
- University of Wisconsin – Madison, Department of Radiology, Madison, Wisconsin, United States
| | - Michael A. Speidel
- University of Wisconsin – Madison, Department of Medical Physics, Madison, Wisconsin, United States
- University of Wisconsin – Madison, Department of Medicine, Madison, Wisconsin, United States
| | - Martin G. Wagner
- University of Wisconsin – Madison, Department of Medical Physics, Madison, Wisconsin, United States
- University of Wisconsin – Madison, Department of Radiology, Madison, Wisconsin, United States
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Maeda M, Omura K, Kan I, Sano T, Nomura K, Takeda T, Ishibashi T, Otori N. Application of Digital Subtraction Angiography in Predicting the Outcomes of Intraoperative Hemorrhage of Juvenile Nasopharyngeal Angiofibroma. World Neurosurg 2023; 178:e339-e344. [PMID: 37480988 DOI: 10.1016/j.wneu.2023.07.065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 07/13/2023] [Accepted: 07/14/2023] [Indexed: 07/24/2023]
Abstract
OBJECTIVE Juvenile nasopharyngeal angiofibroma (JNA) is a very rare hemorrhagic vascular tumor that predominantly affects adolescent boys. The tumor is relatively large when detected, and the risk of intraoperative bleeding is high. We aimed to examine factors associated with intraoperative blood loss in JNA surgery. METHODS Thirteen patients with JNA who underwent surgery at the Jikei University Hospital between 2009 and 2020 were retrospectively reviewed, and factors associated with blood loss were examined by single regression analysis. RESULTS The mean age was 20.8 ± 7.7 years. Preoperative angiographic images were evaluated in 9 of the 13 cases. The 6 patients with the largest bleeding volumes, all had residual nutrient vessels from the internal carotid artery (ICA), with an average number of 2.5 vessels. The mean blood loss of patients with residual nutrient vessels from the ICA was 3037 ± 2568 mL. Single regression analysis of bleeding volume against the number of remaining nutrient vessels from the ICA and the total peak contrast density of nutrient vessels (Cmax) standardized by region of interest showed that the coefficient was positive (P < 0.05 for both), confirming a significant correlation between the 2, respectively. CONCLUSIONS The amount of bleeding significantly correlated with the number of remaining nutrient vessels from the ICA after preoperative embolization and with the total Cmax/region of interest. The ability to predict the amount of preoperative blood loss using this study will facilitate proposals for external incisions in patients with JNA.
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Affiliation(s)
- Mayuka Maeda
- Department of Otolaryngology and Head and Neck Surgery, Self-Defense Forces Central Hospital, Setagaya-ku, Tokyo, Japan; Department of Otolaryngology, The Jikei University Hospital, Minato-ku, Tokyo, Japan
| | - Kazuhiro Omura
- Department of Otolaryngology, The Jikei University Hospital, Minato-ku, Tokyo, Japan.
| | - Issei Kan
- Department of Neurosurgery, The Jikei University Hospital, Minato-ku, Tokyo, Japan
| | - Toru Sano
- Department of Neurosurgery, The Jikei University Hospital, Minato-ku, Tokyo, Japan
| | - Kazuhiro Nomura
- Department of Otolaryngology, Tohoku University, Sendai, Miyagi, Japan
| | - Teppei Takeda
- Department of Otolaryngology, The Jikei University Hospital, Minato-ku, Tokyo, Japan
| | - Toshihiro Ishibashi
- Department of Neurosurgery, The Jikei University Hospital, Minato-ku, Tokyo, Japan
| | - Nobuyoshi Otori
- Department of Otolaryngology, The Jikei University Hospital, Minato-ku, Tokyo, Japan
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Chen KK, Lin CJ. Estimating Pulsatile Flow Velocity using Four-Dimensional Digital Subtraction Angiography . ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023; 2023:1-4. [PMID: 38082691 DOI: 10.1109/embc40787.2023.10340843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
Digital subtraction angiography (DSA) is a X-ray based imaging modality for interventional procedures, and remains criterion standard for diagnosing vascular diseases. The imaging protocol of DSA involves administration of a foreign contrast medium into the blood vessel that opacifies the vasculature during the imaging. Using two-dimensional (2D) DSA with high temporal resolution, it was recently demonstrated that the pulsatile velocity can be estimated by evaluating the temporal and spatial variations of the contrast medium distributions in the blood vessel. In this paper, we evaluate the feasibility to estimate the pulsatile flow velocity using the four-dimensional (4D) DSA. To overcome the noise and artefacts of 4D-DSA data, a empirical mode decomposition plus autocorrelation based method is proposed to estimate the pulsatile velocities, and the pulsatile velocities estimated using 2D-DSA are used as reference for comparison.Clinical Relevance-4D-DSA encompasses both structural and temporal information; it theoretically reduces the need of multiple scans, hence reducing the radiation doses. The estimated pulsatile flow velocities open up a new parameter for hemodynamic studies and potential for real-time diagnostic and therapeutic monitoring during interventional procedures.
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Kohata Y, Ohta M, Jin K, Anzai H. Effects of helical centerline stent vs. straight stent placement on blood flow velocity. FRONTIERS IN MEDICAL TECHNOLOGY 2023; 5:1196125. [PMID: 37333882 PMCID: PMC10272720 DOI: 10.3389/fmedt.2023.1196125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 05/17/2023] [Indexed: 06/20/2023] Open
Abstract
As an approach to maintain patency in femoropopliteal stenting, a helical stent configuration was proposed, which showed improved patency in clinical trials. However, the effects of helical stent placement on the flow have not been quantitatively analyzed. The purpose of this study was to estimate flow velocities to quantify the influence of helical stent placement. Helical and straight stents were implanted in three healthy pigs, and the flow velocities were estimated using the time-intensity curve (TIC) in the angiography images. The angiographic images indicated thinning of the leading edge of the contrast medium through the helically deformed artery, which was not observed in the straight stent. The slower rise of the TIC peak in the helical stent indicated faster travel of this thinner edge. Arterial expansion due to stenting was observed in all cases, and the expansion rate varied according to location. All cases of helical stent implantation showed that velocity was maintained (55.0%-71.3% velocity retention), unlike for straight stent implantation (43.0%-68.0% velocity retention); however, no significant difference was observed.
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Affiliation(s)
- Yutaro Kohata
- Graduate School of Biomedical Engineering, Tohoku University, Sendai, Japan
- Biomedical Flow Dynamics Laboratory, The Institute of Fluid Science, Tohoku University, Sendai, Japan
| | - Makoto Ohta
- Biomedical Flow Dynamics Laboratory, The Institute of Fluid Science, Tohoku University, Sendai, Japan
- ELyTMaXUMI 3757, CNRS – Université de Lyon – Tohoku University, International Joint Unit, Tohoku University, Sendai, Miyagi, Japan
| | - Kazuyoshi Jin
- Graduate School of Biomedical Engineering, Tohoku University, Sendai, Japan
- Biomedical Flow Dynamics Laboratory, The Institute of Fluid Science, Tohoku University, Sendai, Japan
| | - Hitomi Anzai
- Biomedical Flow Dynamics Laboratory, The Institute of Fluid Science, Tohoku University, Sendai, Japan
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Steinman DA. Comprehensive Atlases of Intracranial Blood Flow Rates: A Hard Nut Finally Cracks? Radiology 2023; 307:e230381. [PMID: 36943083 DOI: 10.1148/radiol.230381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
Affiliation(s)
- David A Steinman
- From the University of Toronto, 5 King's College Rd, Toronto, ON, Canada M5S 3G8
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Chen KK, Lin CJ, Chu WF. Dispersion of Heterogeneous Medium in Pulsatile Blood Flow and Absolute Pulsatile Flow Velocity Quantification. IEEE TRANSACTIONS ON MEDICAL IMAGING 2023; 42:170-182. [PMID: 36094983 DOI: 10.1109/tmi.2022.3206241] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Heterogeneous medium enhanced angiogr- ams are key diagnostic tools in clinical practice; the associated hemodynamic information is crucial for diagnosing cardiovascular diseases. However, the dynamics of such medium in physiological blood flow are poorly understood. Herein, we report a previously unnoticed dispersion pattern, which is a universal phenomenon, of a medium in pulsatile blood flow. We present a physical theory for studying the dispersion of a steadily injected heterogeneous medium into a thin tubular blood vessel in which the blood flow is pulsatile. In a thin tubular blood vessel, we demonstrate that variations of concentration associated with the heterogeneous medium obey a one-dimensional advection diffusion equation, and the diffusion has limited effect whenever a short vascular segment is considered. A distinct feature of the distribution of the medium in the axial distance-time plane is a "dilation-retraction" pattern. The time evolution signals at different axial positions exhibit distinct concentration waveforms. A numerical scheme is proposed for exploiting this information to estimate the pulsatile velocity. Artificial data are adopted to validate the scheme. Real X-ray angiography is also analyzed to support our theory and method. The theory is applicable whenever imaging protocols involve a heterogeneous medium in pulsatile flow.
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12
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Marfoglio S, Kovarovic B, Fiorella DJ, Sadasivan C. A novel angiographic method to estimate arterial blood flow rates using contrast reflux: Effect of injection parameters. Med Phys 2023; 50:259-273. [PMID: 36030369 DOI: 10.1002/mp.15948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 07/20/2022] [Accepted: 08/10/2022] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND Contrast reflux, which is the retrograde movement of contrast against flow direction, is commonly observed during angiography. Despite a vast body of literature on angiography, the hemodynamic factors affecting contrast reflux have not been studied. Numerous methods have been developed to extract flow from angiography, but the reliability of these methods is not yet sufficient to be of routine clinical use. PURPOSE To evaluate the effect of baseline blood flow rates and injection conditions on the extent of contrast reflux. To estimate arterial flow rates based on measurement of contrast reflux length. MATERIALS AND METHODS Iodinated contrast was injected into an idealized tube as well as a physiologically accurate model of the cervico-cerebral vasculature. A total of 194 high-speed angiograms were acquired under varying "blood" flow rates and injection conditions (catheter size, injection rate, and injection time). The length of contrast reflux was compared to the input variables and to dimensionless fluid dynamics parameters at the catheter-tip. Arterial blood flow rates were estimated using contrast reflux length as well as a traditional transit-time method and compared to measured flow rates. RESULTS Contrast reflux lengths were significantly affected by contrast injection rate (p < 0.0001), baseline blood flow rate (p = 0.0004), and catheter size (p = 0.04), but not by contrast injection time (p = 0.4). Reflux lengths were found to be correlated to dimensionless fluid dynamics parameters by an exponential function (R2 = 0.6-0.99). When considering the entire dataset in unison, flow estimation errors with the reflux-length method (39% ± 33%) were significantly higher (p = 0.003) than the transit-time method (33% ± 36%). However, when subgrouped by catheter, the error with the reflux-length method was substantially reduced and was significantly lower (14% ± 14%, p < 0.0001) than the transit-time method. CONCLUSION Results show correlations between contrast reflux length and baseline hemodynamic parameters that have not been reported previously. Clinically relevant blood flow rate estimation is feasible by simple measurement of reflux length. In vivo and clinical studies are required to confirm these correlations and to refine the methodology of estimating blood flow by reflux.
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Affiliation(s)
- Samantha Marfoglio
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, USA
| | - Brandon Kovarovic
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, USA
| | - David J Fiorella
- Department of Neurosurgery, Stony Brook University Medical Center, Stony Brook, New York, USA
| | - Chander Sadasivan
- Department of Neurosurgery, Stony Brook University Medical Center, Stony Brook, New York, USA
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Zhang Q, Spincemaille P, Drotman M, Chen C, Eskreis-Winkler S, Huang W, Zhou L, Morgan J, Nguyen TD, Prince MR, Wang Y. Quantitative transport mapping (QTM) for differentiating benign and malignant breast lesion: Comparison with traditional kinetics modeling and semi-quantitative enhancement curve characteristics. Magn Reson Imaging 2022; 86:86-93. [PMID: 34748928 PMCID: PMC8726426 DOI: 10.1016/j.mri.2021.10.039] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Revised: 10/29/2021] [Accepted: 10/30/2021] [Indexed: 02/03/2023]
Abstract
PURPOSE To test the feasibility of using quantitative transport mapping (QTM) method, which is based on the inversion of transport equation using spatial deconvolution without any arterial input function, for automatically postprocessing dynamic contrast enhanced MRI (DCE-MRI) to differentiate malignant and benign breast tumors. MATERIALS AND METHODS Breast DCE-MRI data with biopsy confirmed malignant (n = 13) and benign tumors (n = 13) was used to assess QTM velocity (|u|) and diffusion coefficient (D), volume transfer constant (Ktrans), volume fraction of extravascular extracellular space (Ve) from kinetics method, and traditional enhancement curve characteristics (ECC: amplitude A, wash-in rate α, wash-out rate β). A Mann-Whitney U test and receiver operating characteristic curve (ROC) analysis were performed to assess the diagnostic performance of these parameters for distinguishing between benign and malignant tumors. RESULTS Between malignant and benign tumors, there was a significant difference in |u| and Ktrans, (p = 0.0066, 0.0274, respectively), but not in D, Ve, A, α and β (p = 0.1119, 0.2382, 0.4418,0.2592 and 0.9591, respectively). ROC area-under-the-curve was 0.82, 0.75 (95% confidence level 0.60-0.95, 0.51-0.90) for |u| and Ktrans, respectively. CONCLUSION QTM postprocesses DCE-MRI automatically through deconvolution in space and time to solve the inverse problem of the transport equation. Comparing with traditional kinetics method and ECC, QTM method showed better diagnostic accuracy in differentiating benign from malignant breast tumors in this study.
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Affiliation(s)
- Qihao Zhang
- Department of Radiology, Weill Medical College of Cornell University, New York, NY,Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY
| | - Pascal Spincemaille
- Department of Radiology, Weill Medical College of Cornell University, New York, NY
| | - Michele Drotman
- Department of Radiology, Weill Medical College of Cornell University, New York, NY
| | - Christine Chen
- Department of Radiology, Weill Medical College of Cornell University, New York, NY
| | | | - Weiyuan Huang
- Department of Radiology, Weill Medical College of Cornell University, New York, NY
| | - Liangdong Zhou
- Department of Radiology, Weill Medical College of Cornell University, New York, NY
| | - John Morgan
- Department of Radiology, Weill Medical College of Cornell University, New York, NY
| | - Thanh D. Nguyen
- Department of Radiology, Weill Medical College of Cornell University, New York, NY
| | - Martin R. Prince
- Department of Radiology, Weill Medical College of Cornell University, New York, NY
| | - Yi Wang
- Department of Radiology, Weill Medical College of Cornell University, New York, NY,Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY
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Wu Q, Vassilevski Y, Simakov S, Liang F. Comparison of algorithms for estimating blood flow velocities in cerebral arteries based on the transport information of contrast agent: An in silico study. Comput Biol Med 2021; 141:105040. [PMID: 34809965 DOI: 10.1016/j.compbiomed.2021.105040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 10/27/2021] [Accepted: 11/13/2021] [Indexed: 11/29/2022]
Abstract
While many algorithms have been proposed to estimate blood flow velocities based on the transport information of contrast agent acquired by digital subtraction angiography (DSA), most relevant studies focused on a single vessel, leaving a question open as to whether the algorithms would be suitable for estimating blood flow velocities in arterial systems with complex topological structures. In this study, a one-dimensional (1-D) modeling method was developed to simulate the transport of contrast agent in cerebral arterial networks with various anatomical variations or having occlusive disease, thereby generating an in silico database for examining the accuracies of some typical algorithms (i.e., time-of-center of gravity (TCG), shifted least-squares (SLS), and cross correlation (CC) algorithms) that estimate blood flow velocity based on the concentration-time curves (CTCs) of contrast agent. The results showed that the TCG algorithm had the best performance in estimating blood flow velocities in most cerebral arteries, with the accuracy being only mildly affected by anatomical variations of the cerebral arterial network. Nevertheless, the presence of a stenosis of moderate to high severity in the internal carotid artery could considerably impair the accuracy of the TCG algorithm in estimating blood flow velocities in some cerebral arteries where the transport of contrast agent was disturbed by strong collateral flows. In summary, the study suggests that the TCG algorithm may offer a promising means for estimating blood flow velocities based on CTCs of contrast agent monitored in cerebral arteries, provided that the shapes of CTCs are not highly distorted by collateral flows.
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Affiliation(s)
- Qiyuan Wu
- Department of Engineering Mechanics, School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Yuri Vassilevski
- World-Class Research Center "Digital biodesign and personalized healthcare", Sechenov First Moscow State Medical University, Moscow, 19991, Russia; Marchuk Institute of Numerical Mathematics, Russian Academy of Sciences, Moscow, 119333, Russia
| | - Sergey Simakov
- World-Class Research Center "Digital biodesign and personalized healthcare", Sechenov First Moscow State Medical University, Moscow, 19991, Russia; Moscow Institute of Physics and Technology, Dolgoprudny, 141700, Russia
| | - Fuyou Liang
- Department of Engineering Mechanics, School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China; World-Class Research Center "Digital biodesign and personalized healthcare", Sechenov First Moscow State Medical University, Moscow, 19991, Russia.
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15
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Wang F, Jin P, Feng Y, Fu J, Wang P, Liu X, Zhang Y, Ma Y, Yang Y, Yang A, Feng X. Flexible Doppler ultrasound device for the monitoring of blood flow velocity. SCIENCE ADVANCES 2021; 7:eabi9283. [PMID: 34705515 PMCID: PMC8550238 DOI: 10.1126/sciadv.abi9283] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Accepted: 09/08/2021] [Indexed: 05/27/2023]
Abstract
Thrombosis and restenosis after vascular reconstruction procedures may cause complications such as stroke, but a clinical means to continuously monitor vascular conditions is lacking. Conventional ultrasound probes are rigid, particularly for postoperative patients with fragile skin. Techniques based on photoplethysmography or thermal analysis provide only relative changes in flow volume and have a shallow detection depth. Here, we introduce a flexible Doppler ultrasound device for the continuous monitoring of the absolute velocity of blood flow in deeply embedded arteries based on the Doppler effect. The device is thin (1 mm), lightweight (0.75 g), and skin conforming. When the dual-beam Doppler method is used, the influence of the Doppler angle on the velocity measurement is avoided. Experimental studies on ultrasound phantoms and human subjects demonstrate accurate measurement of the flow velocity. The wearable Doppler device has the potential to enhance the quality of care of patients after reconstruction surgery.
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Affiliation(s)
- Fengle Wang
- AML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
- Center for Flexible Electronics Technology, Tsinghua University, Beijing 100084, China
| | - Peng Jin
- AML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
- Center for Flexible Electronics Technology, Tsinghua University, Beijing 100084, China
| | - Yunlu Feng
- Department of Gastroenterology, Peking Union Medical College Hospital, Beijing 100730, China
| | - Ji Fu
- Institute of Flexible Electronics Technology of THU, Jiaxing 314000, China
| | - Peng Wang
- AML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
- Center for Flexible Electronics Technology, Tsinghua University, Beijing 100084, China
| | - Xin Liu
- AML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
- Center for Flexible Electronics Technology, Tsinghua University, Beijing 100084, China
| | - Yingchao Zhang
- AML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
- Center for Flexible Electronics Technology, Tsinghua University, Beijing 100084, China
| | - Yinji Ma
- AML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
- Center for Flexible Electronics Technology, Tsinghua University, Beijing 100084, China
| | - Yingyun Yang
- Department of Gastroenterology, Peking Union Medical College Hospital, Beijing 100730, China
| | - Aiming Yang
- Department of Gastroenterology, Peking Union Medical College Hospital, Beijing 100730, China
| | - Xue Feng
- AML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
- Center for Flexible Electronics Technology, Tsinghua University, Beijing 100084, China
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Mathematical Models for Blood Flow Quantification in Dialysis Access Using Angiography: A Comparative Study. Diagnostics (Basel) 2021; 11:diagnostics11101771. [PMID: 34679469 PMCID: PMC8534972 DOI: 10.3390/diagnostics11101771] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 09/10/2021] [Accepted: 09/17/2021] [Indexed: 11/26/2022] Open
Abstract
Blood flow rate in dialysis (vascular) access is the key parameter to examine patency and to evaluate the outcomes of various endovascular interve7ntions. While angiography is extensively used for dialysis access–salvage procedures, to date, there is no image-based blood flow measurement application commercially available in the angiography suite. We aim to calculate the blood flow rate in the dialysis access based on cine-angiographic and fluoroscopic image sequences. In this study, we discuss image-based methods to quantify access blood flow in a flow phantom model. Digital subtraction angiography (DSA) and fluoroscopy were used to acquire images at various sampling rates (DSA—3 and 6 frames/s, fluoroscopy—4 and 10 pulses/s). Flow rates were computed based on two bolus tracking algorithms, peak-to-peak and cross-correlation, and modeled with three curve-fitting functions, gamma variate, lagged normal, and polynomial, to correct errors with transit time measurement. Dye propagation distance and the cross-sectional area were calculated by analyzing the contrast enhancement in the vessel. The calculated flow rates were correlated versus an in-line flow sensor measurement. The cross-correlation algorithm with gamma-variate curve fitting had the best accuracy and least variability in both imaging modes. The absolute percent error (mean ± SEM) of flow quantification in the DSA mode at 6 frames/s was 21.4 ± 1.9%, and in the fluoroscopic mode at 10 pulses/s was 37.4 ± 3.6%. The radiation dose varied linearly with the sampling rate in both imaging modes and was substantially low to invoke any tissue reactions or stochastic effects. The cross-correlation algorithm and gamma-variate curve fitting for DSA acquisition at 6 frames/s had the best correlation with the flow sensor measurements. These findings will be helpful to develop a software-based vascular access flow measurement tool for the angiography suite and to optimize the imaging protocol amenable for computational flow applications.
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Avrahami I, Biran H, Liberzon A. Estimation of coronary stenosis severity based on flow distribution ratios. Comput Methods Biomech Biomed Engin 2021; 25:424-438. [PMID: 34320881 DOI: 10.1080/10255842.2021.1957099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
We suggest improving minimally-invasive stenosis severity estimation, using a combination of existing geometry-based methods with Transluminal Attenuation Gradient measurements. Instead of local flow values, the method uses flow distribution ratios along the entire tree. The tree geometry is used to derive a lumped model and predict the 'theoretical' ratios in each bifurcation, while attenuation measurements are used for extracting 'actual' ratios. The discrepancies between the measured and the theoretical values are utilized to assess a functional degree of stenosis. Our experimental and numerical analyses show that the quantitative value of discrepancy is proportional to stenosis severity, regardless of boundary conditions.
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Affiliation(s)
- Idit Avrahami
- Department of Mechanical Engineering and Mechatronics, Ariel University, Ariel, Israel
| | - Hadar Biran
- Department of Mechanical Engineering and Mechatronics, Ariel University, Ariel, Israel.,School of Mechanical Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Alex Liberzon
- School of Mechanical Engineering, Tel Aviv University, Tel Aviv, Israel
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Lu C, Han L, Wang J, Wan J, Song G, Rao J. Engineering of magnetic nanoparticles as magnetic particle imaging tracers. Chem Soc Rev 2021; 50:8102-8146. [PMID: 34047311 DOI: 10.1039/d0cs00260g] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Magnetic particle imaging (MPI) has recently emerged as a promising non-invasive imaging technique because of its signal linearly propotional to the tracer mass, ability to generate positive contrast, low tissue background, unlimited tissue penetration depth, and lack of ionizing radiation. The sensitivity and resolution of MPI are highly dependent on the properties of magnetic nanoparticles (MNPs), and extensive research efforts have been focused on the design and synthesis of tracers. This review examines parameters that dictate the performance of MNPs, including size, shape, composition, surface property, crystallinity, the surrounding environment, and aggregation state to provide guidance for engineering MPI tracers with better performance. Finally, we discuss applications of MPI imaging and its challenges and perspectives in clinical translation.
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Affiliation(s)
- Chang Lu
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, P. R. China.
| | - Linbo Han
- College of Health Science and Environmental Engineering, Shenzhen Technology University, Shenzhen 518118, P. R. China
| | - Joanna Wang
- Molecular Imaging Program at Stanford, Department of Radiology, Stanford University School of Medicine, 1201 Welch Road, Stanford, California 94305-5484, USA.
| | - Jiacheng Wan
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, P. R. China.
| | - Guosheng Song
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, P. R. China.
| | - Jianghong Rao
- Molecular Imaging Program at Stanford, Department of Radiology, Stanford University School of Medicine, 1201 Welch Road, Stanford, California 94305-5484, USA.
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A novel diagnostic approach for assessing pulmonary blood flow distribution using conventional X-ray angiography. PLoS One 2021; 16:e0253565. [PMID: 34185820 PMCID: PMC8241113 DOI: 10.1371/journal.pone.0253565] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 06/08/2021] [Indexed: 11/22/2022] Open
Abstract
Objective Quantitative assessment of pulmonary blood flow distribution is important when determining the clinical indications for treating pulmonary arterial branch stenosis. Lung perfusion scintigraphy is currently the gold standard for quantitative blood flow measurement. However, it is expensive, cannot provide a real-time assessment, requires additional sedation, and exposes the patient to ionizing radiation. The aim of this study was to investigate the feasibility of a novel technology for measuring pulmonary blood flow distribution in each lung by conventional X-ray pulmonary angiography and to compare its performance to that of lung perfusion scintigraphy. Methods Contrast-enhanced X-ray pulmonary angiography images were acquired at a frame rate of 30 frames per second. The baseline mask image, obtained before contrast agent injection, was subtracted from subsequent, consecutive images. The time-signal intensity curves of two regions of interest, established at each lung field, were obtained on a frame-to-frame basis. The net increase in signal intensity within each region at the torrent period during the second cardiac cycle before contrast agent enhancement over the total lung field was measured, and the right-to-left ratio of the signal intensity was calculated. The right-to-left ratio obtained with this approach was compared to that obtained with scintigraphy. Agreement of the right-to-left ratio between X-ray angiography and lung scintigraphy measurements was assessed using linear fitting with the Pearson correlation coefficient. Result The calculation of the right-to-left ratio of pulmonary blood flow by our kinetic model was feasible for seven children as a pilot study. The right-to-left ratio of pulmonary blood flow distribution calculated from pulmonary angiography was in good agreement with that of lung perfusion scintigraphy, with a Pearson correlation coefficient of 0.91 and a slope of linear fit of 1.2 (p<0.005). Conclusion The novel diagnostic technology using X-ray pulmonary angiography from our kinetic model can feasibly quantify the right-to-left ratio of pulmonary blood flow distribution. This technology may serve as a substitute for lung perfusion scintigraphy, which is quite beneficial for small children susceptible to radiation exposure.
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Suvorov NB, Belov AV, Kuliabin KG, Anisimov AA, Sergeev TV, Markelov OA. High Precision Human Skin Temperature Fluctuations Measuring Instrument. SENSORS 2021; 21:s21124101. [PMID: 34203648 PMCID: PMC8232319 DOI: 10.3390/s21124101] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 06/06/2021] [Accepted: 06/11/2021] [Indexed: 11/30/2022]
Abstract
This paper describes the experimental results of testing a prototype of a high precision human skin rapid temperature fluctuations measuring instrument. Based on the author’s work, an original circuit solution on a miniature semiconductor diode sensor has been designed. The proposed circuitry provides operation in the full voltage range with automatic setting and holding the operating point, as well as the necessary slope of the conversion coefficient (up to 2300 mV/°C), which makes it possible to register fast temperature oscillations from the surface of the human body and other biological objects. Simulation results in the Microcap 12 software and laboratory tests have confirmed all declared design specifications: temperature resolution of 0.01 °C, transducer thermal time constant of 0.05 s. An original thermostat and an experimental setup for the simultaneous registration of the electrocardiogram, pulse wave signals from the Biopac polygraph MP36 and a signal of temperature oscillations from the prototype thermometer have been designed for further investigations. The preliminary test results indicates that using the designed measuring instrument gives a possibility to provide an in-depth study of the relationship between micro- and macro-blood circulations manifested in skin temperature fluctuations.
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Affiliation(s)
- Nikolai B. Suvorov
- Department of Ecological Physiology, Federal State Budgetary Scientific Institution “Institute of Experimental Medicine”, 12 Acad. Pavlov Str., 197376 Saint Petersburg, Russia; (N.B.S.); (A.V.B.); (K.G.K.); (A.A.A.); (T.V.S.)
| | - Alexander V. Belov
- Department of Ecological Physiology, Federal State Budgetary Scientific Institution “Institute of Experimental Medicine”, 12 Acad. Pavlov Str., 197376 Saint Petersburg, Russia; (N.B.S.); (A.V.B.); (K.G.K.); (A.A.A.); (T.V.S.)
| | - Konstantin G. Kuliabin
- Department of Ecological Physiology, Federal State Budgetary Scientific Institution “Institute of Experimental Medicine”, 12 Acad. Pavlov Str., 197376 Saint Petersburg, Russia; (N.B.S.); (A.V.B.); (K.G.K.); (A.A.A.); (T.V.S.)
| | - Aleksei A. Anisimov
- Department of Ecological Physiology, Federal State Budgetary Scientific Institution “Institute of Experimental Medicine”, 12 Acad. Pavlov Str., 197376 Saint Petersburg, Russia; (N.B.S.); (A.V.B.); (K.G.K.); (A.A.A.); (T.V.S.)
- Department of Biomedical Engineering, Saint Petersburg Electrotechnical University “LETI”, 5 Prof. Popov Str., 197376 Saint Petersburg, Russia
| | - Timofei V. Sergeev
- Department of Ecological Physiology, Federal State Budgetary Scientific Institution “Institute of Experimental Medicine”, 12 Acad. Pavlov Str., 197376 Saint Petersburg, Russia; (N.B.S.); (A.V.B.); (K.G.K.); (A.A.A.); (T.V.S.)
- Department of Biomedical Engineering, Saint Petersburg Electrotechnical University “LETI”, 5 Prof. Popov Str., 197376 Saint Petersburg, Russia
| | - Oleg A. Markelov
- Department of Biomedical Engineering, Saint Petersburg Electrotechnical University “LETI”, 5 Prof. Popov Str., 197376 Saint Petersburg, Russia
- Correspondence:
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Yeshua T, Gleisner O, Lederman R, Neeman V, Duvdevani M, Leichter I. A novel method for estimating the urine drainage time from the renal collecting system. Abdom Radiol (NY) 2021; 46:2647-2655. [PMID: 33386909 DOI: 10.1007/s00261-020-02880-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 11/13/2020] [Accepted: 11/21/2020] [Indexed: 10/22/2022]
Abstract
PURPOSE Partial obstruction of the upper urinary tract is a common urological pathology that leads to progressive atrophy and dysfunction of the kidney. Most methods for evaluating the urine drainage rate, to assess the severity of partial obstruction, involve injection of markers into the blood stream and therefore the filtration rate from the blood effects the drainage rate. This study presents a novel method for assessing the drainage rate from the upper urinary tract by analyzing sequential fluoroscopic images from a routine nephrostogram, in which contrast material is introduced directly into the renal collecting system. METHODS Fluoroscopic images from 36 nephrostograms, following percutaneous nephrolithotomy, were retrospectively evaluated, 19 with a dilated renal pelvis. A radiological model for calculating the radiopacity of the renal pelvis, which reflects the amount of contrast material in each sequential image, was developed. Using this model, an algorithm was designed for generating a drainage curve and calculating the "drainage time" t1/2 in which half of the contrast material has drained from the renal pelvis. RESULTS Analysis of images of a step-wedge phantom made of an increasing number of contrast material layers showed that the calculated radiopacity of each step was proportional to the amount of contrast material, independent of the background attenuation. Analysis of the nephrostograms showed that the drainage curves highly fitted an exponential function (R = 0.961), with a significantly higher t1/2 for dilated cases. CONCLUSION The developed method may be used for a quantitative and accurate estimation of the urine drainage rate.
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Shields A, Nagesh SVS, Ionita C, Bednarek DR, Rudin S. Evaluation of methods to derive blood flow velocity from 1000 fps high-speed angiographic sequences (HSA) using optical flow (OF) and computational fluid dynamics (CFD). PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2021; 11595. [PMID: 33814671 DOI: 10.1117/12.2580881] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Digital Subtraction Angiography (DSA) is considered the gold standard for imaging and guiding treatment of neurovascular lesions, such as cerebral aneurysms and carotid stenoses. Though DSA can show high-resolution morphology, it remains difficult to extract temporal physiological information, because higher frame-rates are necessary to accurately quantify neurovascular flow details. Recent advances in photon-counting detector technology have led us to develop High-Speed Angiography (HSA), where X-ray images are acquired at 1000 fps for more accurate visualization and quantification of blood flow. Blood flow was imaged using HSA under constant flow conditions within various 3D printed patient-specific phantoms. Blood velocity was quantified using an open source Optical Flow algorithm, OpenOpticalFlow, to perform velocity estimation based on the spatio-temporal intensity changes of iodinated contrast wavefronts. The results of these algorithms are then compared with Computational Fluid Dynamics (CFD) simulations, using the same inlet boundary conditions and model geometries. The performance of these algorithms at lower temporal resolution was then also assessed by simulating lower frame rates from the acquired 1000 fps data. It is important to ascertain the hemodynamic effect of abnormal neurovascular conditions, as well as their effect on treatment of such conditions during the actual clinical interventional procedure. While theoretical CFD results requiring considerable computer capability are delayed for hours or more, it is expected that clinical results from multiple HSA sequences will be available almost immediately while the patient is still under treatment, and even right after flow conditions are changed beneficially by the intervention.
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Affiliation(s)
- A Shields
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY
| | - S V Setlur Nagesh
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY
| | - C Ionita
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY
| | - D R Bednarek
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY
| | - S Rudin
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY
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Chen KK, Lin CJ, Guo WY, Chu WF, Wu YT. Estimating blood flow velocity using time-resolved 3D angiography and a derived physical law of contrast media. Physiol Meas 2021; 42:025007. [PMID: 33498022 DOI: 10.1088/1361-6579/abe022] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Four-dimensional (4D) digital subtraction angiography (DSA) offers a method for evaluating hemodynamics. It is, however, unclear how the delivered contrast medium interacts with the physiological blood flow, and how hemodynamic information may be inferred from the mixture of the contrast medium and blood. In this study, we present a theoretical explanation of contrast dynamics, and an accompanying algorithm for estimating blood flow velocity. APPROACH We retrospectively recruited 23 patients who underwent both 4D DSA and magnetic resonance (MR) phase-contrast imaging. The 4D DSA-reconstructed contrast dynamics were first studied for the internal carotid arteries. Using physical laws governing fluid motion within a curved tube, we showed that the reconstructed contrast dynamics obeyed a simple advection equation. We then proposed an algorithm for estimating the contrast dynamics using angiographic data, and subsequently estimated the axial blood flow velocity using an advection equation. MAIN RESULTS The estimated velocities were compared using three techniques: the Fourier technique, Lin's method, and MR phase contrast. Testing with noise-corrupted artificial data showed that the proposed algorithm was noise resistant. The velocities of 23 patients computed by 4D DSA using the proposed algorithm showed a moderate correlation with the MR phase contrast (r = 0.61), and good correlations with the other two techniques (r = 0.75 and r = 0.72). SIGNIFICANCE The proposed algorithm and has been applied to blood vessel segments with poor signal-to-noise ratios and axial lengths of less than 3 cm, and has a physical basis for computing axial flow velocities using an advection equation. The results of the proposed algorithm are consistent with existing methods.
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Affiliation(s)
- Ko-Kung Chen
- Taipei Veterans General Hospital, Department of Radiology, Taipei, Taiwan
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Hoffman C, Periyasamy S, Longhurst C, Medero R, Roldan-Alzate A, Speidel MA, Laeseke PF. A technique for intra-procedural blood velocity quantitation using time-resolved 2D digital subtraction angiography. CVIR Endovasc 2021; 4:11. [PMID: 33411087 PMCID: PMC7790988 DOI: 10.1186/s42155-020-00199-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 12/15/2020] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND 2D digital subtraction angiography (DSA) is utilized qualitatively to assess blood velocity changes that occur during arterial interventions. Quantitative angiographic metrics, such as blood velocity, could be used to standardize endpoints during angiographic interventions. PURPOSE To assess the accuracy and precision of a quantitative 2D DSA (qDSA) technique and to determine its feasibility for in vivo measurements of blood velocity. MATERIALS AND METHODS A quantitative DSA technique was developed to calculate intra-procedural blood velocity. In vitro validation was performed by comparing velocities from the qDSA method and an ultrasonic flow probe in a bifurcation phantom. Parameters of interest included baseline flow rate, contrast injection rate, projection angle, and magnification. In vivo qDSA analysis was completed in five different branches of the abdominal aorta in two 50 kg swine and compared to 4D Flow MRI. Linear regression, Bland-Altman, Pearson's correlation coefficient and chi squared tests were used to assess the accuracy and precision of the technique. RESULTS In vitro validation showed strong correlation between qDSA and flow probe velocities over a range of contrast injection and baseline flow rates (slope = 1.012, 95% CI [0.989,1.035], Pearson's r = 0.996, p < .0001). The application of projection angle and magnification corrections decreased variance to less than 5% the average baseline velocity (p = 0.999 and p = 0.956, respectively). In vivo validation showed strong correlation with a small bias between qDSA and 4D Flow MRI velocities for all five abdominopelvic arterial vessels of interest (slope = 1.01, Pearson's r = 0.880, p = <.01, Bias = 0.117 cm/s). CONCLUSION The proposed method allows for accurate and precise calculation of blood velocities, in near real-time, from time resolved 2D DSAs.
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Affiliation(s)
- Carson Hoffman
- Department of Medical Physics, University of Wisconsin - Madison, 1111 Highland Ave, Madison, WI, 53705, USA
| | - Sarvesh Periyasamy
- Department of Biomedical Engineering, University of Wisconsin - Madison, 1111 Highland Ave, Madison, WI, 53705, USA
| | - Colin Longhurst
- Department of Biostatistics and Medical Informatics, University of Wisconsin - Madison, 1111 Highland Ave, Madison, WI, 53705, USA
| | - Rafael Medero
- Department of Mechanical Engineering, University of Wisconsin - Madison, 1111 Highland Ave, Madison, WI, 53705, USA
| | - Alejandro Roldan-Alzate
- Department of Biomedical Engineering, University of Wisconsin - Madison, 1111 Highland Ave, Madison, WI, 53705, USA.,Department of Mechanical Engineering, University of Wisconsin - Madison, 1111 Highland Ave, Madison, WI, 53705, USA.,Department of Radiology, University of Wisconsin - Madison, 1111 Highland Ave, Madison, WI, 53705, USA
| | - Michael A Speidel
- Department of Medical Physics, University of Wisconsin - Madison, 1111 Highland Ave, Madison, WI, 53705, USA
| | - Paul F Laeseke
- Section of Interventional Radiology, Department of Radiology, University of Wisconsin - Madison, 600 Highland Ave, Madison, WI, 53792, USA.
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Qiu L, Ouyang Y, Feng Y, Zhang X, Wang X. In vivo skin thermophysical property testing technology using flexible thermosensor-based 3 ω method. INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER 2020; 163:120550. [PMID: 33071298 PMCID: PMC7546650 DOI: 10.1016/j.ijheatmasstransfer.2020.120550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 09/18/2020] [Accepted: 09/28/2020] [Indexed: 05/05/2023]
Abstract
Thermophysical properties of human skin surface and subsurface can reflect the hydration state of the skin and the blood flow rate in the near surface microvessels, which reveals important physiological information related to dermatology and overall health status of human body. Although a few techniques have been developed to measure these signs, complicated devices are required and the subjects need to be completely fixed during the test period. Here, a flexible thermosensor-based 3ω technology was used to monitor thermal conductivity of human skins at different states. Through the analysis of these characteristics, the corresponding physiological state can be established, which can provide a new detection method for the evaluation or prediction of human health status.
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Affiliation(s)
- Lin Qiu
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China
- Beijing Key Laboratory of Energy Saving and Emission Reduction for Metallurgical Industry, University of Science and Technology Beijing, Beijing, 100083, China
| | - Yuxin Ouyang
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China
- Beijing Key Laboratory of Energy Saving and Emission Reduction for Metallurgical Industry, University of Science and Technology Beijing, Beijing, 100083, China
| | - Yanhui Feng
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China
- Beijing Key Laboratory of Energy Saving and Emission Reduction for Metallurgical Industry, University of Science and Technology Beijing, Beijing, 100083, China
| | - Xinxin Zhang
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China
- Beijing Key Laboratory of Energy Saving and Emission Reduction for Metallurgical Industry, University of Science and Technology Beijing, Beijing, 100083, China
| | - Xiaotian Wang
- School of Chemistry, Beihang University, Beijing, 100191, China
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Periyasamy S, Hoffman CA, Longhurst C, Schefelker GC, Ozkan OS, Speidel MA, Laeseke PF. A Quantitative Digital Subtraction Angiography Technique for Characterizing Reduction in Hepatic Arterial Blood Flow During Transarterial Embolization. Cardiovasc Intervent Radiol 2020; 44:310-317. [PMID: 33025244 DOI: 10.1007/s00270-020-02640-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 08/27/2020] [Indexed: 01/20/2023]
Abstract
OBJECTIVE There is no standardized and objective method for determining the optimal treatment endpoint (sub-stasis) during transarterial embolization. The objective of this study was to demonstrate the feasibility of using a quantitative digital subtraction angiography (qDSA) technique to characterize intra-procedural changes in hepatic arterial blood flow velocity in response to transarterial embolization in an in vivo porcine model. MATERIALS AND METHODS Eight domestic swine underwent bland transarterial embolizations to partial- and sub-stasis angiographic endpoints with intraprocedural DSA acquisitions. Embolized lobes were assessed on histopathology for ischemic damage and tissue embolic particle density. Analysis of target vessels used qDSA and a commercially available color-coded DSA (ccDSA) tool to calculate blood flow velocities and time-to-peak, respectively. RESULTS Blood flow velocities calculated using qDSA showed a statistically significant difference (p < 0.01) between partial- and sub-stasis endpoints, whereas time-to-peak calculated using ccDSA did not show a significant difference. During the course of embolizations, the average correlation with volume of particles delivered was larger for qDSA (- 0.86) than ccDSA (0.36). There was a statistically smaller mean squared error (p < 0.01) and larger coefficient of determination (p < 0.01) for qDSA compared to ccDSA. On pathology, the degree of embolization as calculated by qDSA had a moderate, positive correlation (p < 0.01) with the tissue embolic particle density of ischemic regions within the embolized lobe. CONCLUSIONS qDSA was able to quantitatively discriminate angiographic embolization endpoints and, compared to a commercially available ccDSA method, improve intra-procedural characterization of blood flow changes. Additionally, the qDSA endpoints correlated with tissue-level changes.
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Affiliation(s)
- Sarvesh Periyasamy
- Department of Biomedical Engineering, University of Wisconsin - Madison, 1310-C WIMR, 1111 Highland Avenue, Madison, WI, 53705, USA. .,Department of Radiology, University of Wisconsin - Madison, Madison, WI, USA.
| | - Carson A Hoffman
- Department of Medical Physics, University of Wisconsin - Madison, Madison, WI, USA
| | - Colin Longhurst
- Department of Biostatistics and Medical Informatics, University of Wisconsin - Madison, Madison, WI, USA
| | | | - Orhan S Ozkan
- Department of Radiology, University of Wisconsin - Madison, Madison, WI, USA
| | - Michael A Speidel
- Department of Medical Physics, University of Wisconsin - Madison, Madison, WI, USA
| | - Paul F Laeseke
- Department of Radiology, University of Wisconsin - Madison, Madison, WI, USA
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Koirala N, McLennan G. Blood flow quantification in dialysis access using digital subtraction angiography: A retrospective study. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2020; 190:105379. [PMID: 32050137 DOI: 10.1016/j.cmpb.2020.105379] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 01/29/2020] [Accepted: 01/31/2020] [Indexed: 06/10/2023]
Abstract
BACKGROUND AND OBJECTIVE Vascular access is the "lifeline" of end-stage renal disease patients, which is surgically constructed to remove blood-waste and return artificially filtered blood into circulation. The arteriovenous shunting causes an abrupt change in blood flow and results in increased fluidic stress, which predisposes to access stenosis and thrombosis. While access flow is crucial to evaluate interventional endpoint, application to measure flow using digital angiogram is not yet available. The goal of this study was to determine the feasibility of flow quantification in dialysis access using a software tool and to guide the design of an imaging protocol. METHODS 173 digital subtraction angiographic (DSA) images were retrospectively analyzed to evaluate access flow in a custom-programming environment. Four bolus transit time algorithms and a distance calculation method were assessed for flow computation. Gamma variate function was applied to remove secondary flow and intensity outliers in the bolus time-intensity curves and evaluated for enhancement in computational accuracy. The percent deviations of flow rates computed from dilution of iodinated radio-contrast material were compared with in situ catheter-based flow measurement. RESULTS Among the implemented bolus transit time algorithms, quantification error (mean ± standard error) of cross-correlation algorithm without and with gamma variate curve fitting was 35 ± 1% and 22 ± 1%, respectively. All other algorithms had quantification error >27%. The bias and limits of agreement of the cross-correlation algorithm with gamma variate curve fit was -94 ml/min and [-353, 165] mL/min, respectively. CONCLUSIONS The cross-correlation algorithm with gamma variate curve fit had the best accuracy and reproducibility for image-based blood flow computation. To further enhance accuracy, images may need to be acquired with a dedicated injection protocol with predetermined parameters such as the duration, rate and mode of bolus injection, and the acquisition frame rate.
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Affiliation(s)
- Nischal Koirala
- Department of Chemical and Biomedical Engineering, Cleveland State University, Cleveland, OH, USA; Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Gordon McLennan
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA; Division of Vascular and Interventional Radiology, Imaging Institute, Cleveland Clinic, Cleveland, OH, USA.
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Falk KL, Harvey EC, Schafer S, Speidel MA, Strother CM. Optimizing the Quality of 4D-DSA Temporal Information. AJNR Am J Neuroradiol 2019; 40:2124-2129. [PMID: 31672837 PMCID: PMC6975361 DOI: 10.3174/ajnr.a6290] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Accepted: 09/03/2019] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Quantification of blood flow using a 4D-DSA would be useful in the diagnosis and treatment of cerebrovascular diseases. A protocol optimizing identification of density variations in the time-density curves of a 4D-DSA has not been defined. Our purpose was to determine the contrast injection protocol most likely to result in the optimal pulsatility signal strength. MATERIALS AND METHODS Two 3D-printed patient-specific models were used and connected to a pulsatile pump and flow system, which delivered 250-260 mL/min to the model. Contrast medium (Isovue, 370 mg I/mL, 75% dilution) was injected through a 6F catheter positioned upstream from the inlet of the model. 4D-DSA acquisitions were performed for the following injection rates: 1.5, 2.0, 2.5, 3.0 and 3.5 mL/s for 8 seconds. To determine pulsatility, we analyzed the time-density curve at the inlets using the oscillation amplitude and a previously described numeric metric, the sideband ratio. Vascular geometry from 4D-DSA reconstructions was compared with ground truth and micro-CT measurements of the model. Dimensionless numbers that characterize hemodynamics, Reynolds and Craya-Curtet, were calculated for each injection rate. RESULTS The strongest pulsatility signal occurred with the 2.5 mL/s injections. The largest oscillation amplitudes were found with 2.0- and 2.5-mL/s injections. Geometric accuracy was best preserved with injection rates of >1.5 mL/s. CONCLUSIONS An injection rate of 2.5 mL/s provided the strongest pulsatility signal in the 4D-DSA time-density curve. Geometric accuracy was best preserved with injection rates above 1.5 mL/s. These results may be useful in future in vivo studies of blood flow quantification.
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Affiliation(s)
- K L Falk
- From the Department of Biomedical Engineering (K.L.R.)
| | - E C Harvey
- Department of Medical Physics (E.H., M.A.S.)
| | - S Schafer
- Siemens Healthineers Forchheim Germany (S.S.), Hoffman Estates, Illinois
| | - M A Speidel
- Department of Medical Physics (E.H., M.A.S.)
| | - C M Strother
- Department of Radiology (C.M.S.), University of Wisconsin-Madison, Madison, Wisconsin
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Phellan R, Lindner T, Helle M, Falcao AX, Yasuda CL, Sokolska M, Jager RH, Forkert ND. Segmentation-Based Blood Flow Parameter Refinement in Cerebrovascular Structures Using 4-D Arterial Spin Labeling MRA. IEEE Trans Biomed Eng 2019; 67:1936-1946. [PMID: 31689181 DOI: 10.1109/tbme.2019.2951082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
OBJECTIVE Cerebrovascular diseases are one of the main global causes of death and disability in the adult population. The preferred imaging modality for the diagnostic routine is digital subtraction angiography, an invasive modality. Time-resolved three-dimensional arterial spin labeling magnetic resonance angiography (4D ASL MRA) is an alternative non-invasive modality, which captures morphological and blood flow data of the cerebrovascular system, with high spatial and temporal resolution. This work proposes advanced medical image processing methods that extract the anatomical and hemodynamic information contained in 4D ASL MRA datasets. METHODS A previously published segmentation method, which uses blood flow data to improve its accuracy, is extended to estimate blood flow parameters by fitting a mathematical model to the measured vascular signal. The estimated values are then refined using regression techniques within the cerebrovascular segmentation. The proposed method was evaluated using fifteen 4D ASL MRA phantoms, with ground-truth morphological and hemodynamic data, fifteen 4D ASL MRA datasets acquired from healthy volunteers, and two 4D ASL MRA datasets from patients with a stenosis. RESULTS The proposed method reached an average Dice similarity coefficient of 0.957 and 0.938 in the phantom and real dataset segmentation evaluations, respectively. The estimated blood flow parameter values are more similar to the ground-truth values after the refinement step, when using phantoms. A qualitative analysis showed that the refined blood flow estimation is more realistic compared to the raw hemodynamic parameters. CONCLUSION The proposed method can provide accurate segmentations and blood flow parameter estimations in the cerebrovascular system using 4D ASL MRA datasets. SIGNIFICANCE The information obtained with the proposed method can help clinicians and researchers to study the cerebrovascular system non-invasively.
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Change in Perfusion Angiography During Transcatheter Arterial Chemoembolization for Hepatocellular Carcinoma Predicts Short-Term Outcomes. AJR Am J Roentgenol 2019; 213:746-754. [DOI: 10.2214/ajr.18.20499] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Sadasivan C, Dholakia R, Peeling L, Gölitz P, Doerfler A, Lieber BB, Fiorella DJ, Woo HH. Angiographic assessment of the efficacy of flow diverter treatment for cerebral aneurysms. Interv Neuroradiol 2019; 25:655-663. [PMID: 31296064 DOI: 10.1177/1591019919860829] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND The recent growth of neuro-endovascular treatment has rekindled interest in the use of angiographic techniques for flow assessment. Aneurysm treatment with flow diverters is particularly amenable to such analysis. We analyze contrast time-density curves - recorded within aneurysms before (pre) and immediately after (post) flow diverter implantation to estimate six-month treatment outcomes. METHODS Fifty-six patients with 65 aneurysms were treated with flow diverters at two institutions. A region of interest was drawn around the aneurysm perimeter in image sequences taken both pre and post angiography, and the temporal variation in grayscale intensity within the aneurysm (time-density curve) was recorded. Eleven parameters were quantified from each time-density curve. Aneurysm occlusion status was recorded six months post treatment. The change in parameters from pre to post treatment was statistically evaluated between aneurysm occluded and non-occluded groups. RESULTS Of the 11 parameters, eight were significantly different before and immediately after flow diversion. Considering the entire data set, none of the parameters was statistically different between the occluded and non-occluded groups. However, subgroup analyses showed that four variables were significantly different between the aneurysm occluded and non-occluded groups. The sensitivity of these variables to predict aneurysm occlusion at six months ranged from 60% to 89%, while the specificity ranged from 55% to 70%. CONCLUSIONS Device-induced intra-aneurysmal flow alterations quantified by simple aneurysmal time-density curves can potentially be used to predict long-term outcomes of flow diversion. Large multi-center studies will be required to confirm these findings. Patient-to-patient variability in coagulation may need to be incorporated for clinically relevant predictive values.
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Affiliation(s)
- Chander Sadasivan
- Department of Neurosurgery, Stony Brook University Medical Center, Stony Brook, USA
| | - Ronak Dholakia
- Department of Neurosurgery, Stony Brook University Medical Center, Stony Brook, USA
| | - Lissa Peeling
- Department of Neurosurgery, Stony Brook University Medical Center, Stony Brook, USA
| | - Philipp Gölitz
- Department of Neuroradiology, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Arnd Doerfler
- Department of Neuroradiology, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Baruch B Lieber
- Department of Neurosurgery, Stony Brook University Medical Center, Stony Brook, USA
| | - David J Fiorella
- Department of Neurosurgery, Stony Brook University Medical Center, Stony Brook, USA
| | - Henry H Woo
- Department of Neurosurgery, Stony Brook University Medical Center, Stony Brook, USA
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Koirala N, Chauhan N, Thompson D, Karimloo Z, Wunderle K, McLennan G. Quantification of Blood Flow in Dialysis Access Using Custom-Acquisition Protocol and Imaging Methods: A Clinical Validation Study. J Vasc Interv Radiol 2019; 30:1062-1068.e2. [DOI: 10.1016/j.jvir.2018.10.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 10/23/2018] [Accepted: 10/23/2018] [Indexed: 10/27/2022] Open
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YANG ZIFENG, JOHNSON MARK. Velocimetry based on dye visualization for a pulsatile tubing flow measurement. APPLIED OPTICS 2019; 58:C7-C13. [PMID: 31045025 PMCID: PMC6594178 DOI: 10.1364/ao.58.0000c7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 12/08/2018] [Indexed: 06/09/2023]
Abstract
A dye visualization experiment was designed and operated as an analogy of x-ray angiographic imaging. The velocimetry technique based on dye visualization for a pulsatile tubing flow measurement is introduced. The optical flow method was utilized to recover the velocity field from the visualization images. For the same flow condition, a digital particle image velocimetry (PIV) system was also employed to measure the same flow field in the middle plane. The purpose of this study was to determine the accuracy of the velocity field estimation from the transmittance-based two-dimensional projection image of the three-dimensional volumetric flow field by dye visualization in comparison with the PIV measurement results. Compared to the PIV results in the middle plane, the averaged velocity magnitude from the dye visualization measurement was underestimated by about 16%-24% in the central region and by about 29%-43% in the outer region across the tube at two time instants of the cyclic pulsatile flow.
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Bouillot P, Brina O, Chnafa C, Cancelliere NM, Vargas MI, Radovanovic I, Krings T, Steinman DA, Pereira VM. Robust cerebrovascular blood velocity and flow rate estimation from 4D‐CTA. Med Phys 2019; 46:2126-2136. [DOI: 10.1002/mp.13454] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 01/27/2019] [Accepted: 02/13/2019] [Indexed: 01/22/2023] Open
Affiliation(s)
- Pierre Bouillot
- Departement of Neuroradiology Geneva University Hospitals Geneva Switzerland
- Department of Quantum Matter Physics University of Geneva Geneva Switzerland
| | - Olivier Brina
- Departement of Neuroradiology Geneva University Hospitals Geneva Switzerland
- Division of Neuroradiology Department of Medical Imaging Toronto Western Hospital University Health Network Toronto ON Canada
| | - Christophe Chnafa
- Biomedical Simulation Laboratory Department of Mechanical & Industrial Engineering University of Toronto Toronto ON Canada
| | - Nicole M. Cancelliere
- Division of Neuroradiology Department of Medical Imaging Toronto Western Hospital University Health Network Toronto ON Canada
| | - Maria I. Vargas
- Departement of Neuroradiology Geneva University Hospitals Geneva Switzerland
| | - Ivan Radovanovic
- Division of Neurosurgery Department of Surgery Toronto Western Hospital University Health Network Toronto ON Canada
| | - Timo Krings
- Division of Neuroradiology Department of Medical Imaging Toronto Western Hospital University Health Network Toronto ON Canada
| | - David A. Steinman
- Biomedical Simulation Laboratory Department of Mechanical & Industrial Engineering University of Toronto Toronto ON Canada
| | - Vitor M. Pereira
- Departement of Neuroradiology Geneva University Hospitals Geneva Switzerland
- Division of Neuroradiology Department of Medical Imaging Toronto Western Hospital University Health Network Toronto ON Canada
- Division of Neurosurgery Department of Surgery Toronto Western Hospital University Health Network Toronto ON Canada
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Correlation-based perfusion mapping using time-resolved MR angiography: A feasibility study for patients with suspicions of steno-occlusive craniocervical arteries. Eur Radiol 2018; 28:4890-4899. [DOI: 10.1007/s00330-018-5468-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 03/13/2018] [Accepted: 04/09/2018] [Indexed: 10/16/2022]
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Wu Y, Shaughnessy G, Hoffman CA, Oberstar EL, Schafer S, Schubert T, Ruedinger KL, Davis BJ, Mistretta CA, Strother CM, Speidel MA. Quantification of Blood Velocity with 4D Digital Subtraction Angiography Using the Shifted Least-Squares Method. AJNR Am J Neuroradiol 2018; 39:1871-1877. [PMID: 30213811 PMCID: PMC6177311 DOI: 10.3174/ajnr.a5793] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 06/11/2018] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE 4D-DSA provides time-resolved 3D-DSA volumes with high temporal and spatial resolutions. The purpose of this study is to investigate a shifted least squares method to estimate the blood velocity from the 4D DSA images. Quantitative validation was performed using a flow phantom with an ultrasonic flow probe as ground truth. Quantification of blood velocity in human internal carotid arteries was compared with measurements generated from 3D phase-contrast MR imaging. MATERIALS AND METHODS The centerlines of selected vascular segments and the time concentration curves of each voxel along the centerlines were determined from the 4D-DSA dataset. The temporal shift required to achieve a minimum difference between any point and other points along the centerline of a segment was calculated. The temporal shift as a function of centerline point position was fit to a straight line to generate the velocity. The proposed shifted least-squares method was first validated using a flow phantom study. Blood velocities were also estimated in the 14 ICAs of human subjects who had both 4D-DSA and phase-contrast MR imaging studies. Linear regression and correlation analysis were performed on both the phantom study and clinical study, respectively. RESULTS Mean velocities of the flow phantom calculated from 4D-DSA matched very well with ultrasonic flow probe measurements with 11% relative root mean square error. Mean blood velocities of ICAs calculated from 4D-DSA correlated well with phase-contrast MR imaging measurements with Pearson correlation coefficient r = 0.835. CONCLUSIONS The availability of 4D-DSA provides the opportunity to use the shifted least-squares method to estimate velocity in vessels within a 3D volume.
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Affiliation(s)
- Y Wu
- From the Departments of Medical Physics (Y.W., G.S., C.A.H., C.A.M., M.A.S.)
| | - G Shaughnessy
- From the Departments of Medical Physics (Y.W., G.S., C.A.H., C.A.M., M.A.S.)
| | - C A Hoffman
- From the Departments of Medical Physics (Y.W., G.S., C.A.H., C.A.M., M.A.S.)
| | | | | | - T Schubert
- Radiology (C.A.M., C.M.S., T.S.).,Department of Radiology and Nuclear Medicine (T.S.), Basel University Hospital, Basel, Switzerland
| | | | - B J Davis
- Biomedical Engineering (E.L.O., K.L.R., B.J.D.)
| | - C A Mistretta
- From the Departments of Medical Physics (Y.W., G.S., C.A.H., C.A.M., M.A.S.).,Radiology (C.A.M., C.M.S., T.S.)
| | | | - M A Speidel
- From the Departments of Medical Physics (Y.W., G.S., C.A.H., C.A.M., M.A.S.).,Medicine (M.A.S.), University of Wisconsin, Madison, Wisconsin
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Shaughnessy G, Schafer S, Speidel MA, Strother CM, Mistretta CA. Measuring blood velocity using 4D-DSA: A feasibility study. Med Phys 2018; 45:4510-4518. [PMID: 30102773 DOI: 10.1002/mp.13120] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 07/11/2018] [Accepted: 07/11/2018] [Indexed: 11/08/2022] Open
Abstract
PURPOSE Four-dimensional (4D) DSA reconstruction provides three-dimensional (3D) time-resolved visualization of contrast bolus passage through arterial vasculature in the interventional setting. The purpose of this study was to evaluate the feasibility of using these data in measuring blood velocity and flow. METHODS The pulsatile signals in the time concentration curves (TCCs) measured at different points along a vessel are markers of the movement of a contrast bolus and thus of blood flow. When combined with the spatial content, that is, geometry of the vasculature, this information then provides the data required to determine blood velocity. A Fourier-based algorithm was used to identify and follow the pulsatility signal. A Side Band Ratio (SBR) metric was used to reduce uncertainty in identifying the pulsatility in regions where the signal was weak. We tested this method using 4D-DSA reconstructions from vascular phantoms as well as from human studies. RESULTS In five studies using 3D printed patient-specific cerebrovascular phantoms, velocities calculated from the 4D-DSAs were found to be within 10% of velocities measured with a flow meter. Calculated velocity and flow values from three human studies were within the range of those reported in the literature. CONCLUSIONS 4D-DSA provides temporal and spatial information about blood flow and vascular geometry. This information is obtained using conventional rotational angiographic systems. In this small feasibility study, these data allowed calculations of velocity values that correlated well with measured values. The availability of velocity and blood flow information in the interventional setting would support a more quantitative approach to diagnosis, treatment planning and post-treatment evaluations of a variety of cerebrovascular diseases.
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Affiliation(s)
- Gabe Shaughnessy
- Department of Medical Physics, University of Wisconsin, Madison, WI, USA
| | | | - Michael A Speidel
- Department of Medical Physics, University of Wisconsin, Madison, WI, USA
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Singh R, Jaffe A, Frydman GH, Najia MAT, Wei Z, Yang J, Majmudar MD. Noninvasive Assessment of Jugular Venous Pressure via Force-Coupled Single Crystal Ultrasound. IEEE Trans Biomed Eng 2018; 65:1705-1710. [PMID: 29989920 DOI: 10.1109/tbme.2017.2767828] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVE we have developed a handheld device for noninvasive quantitative assessment of jugular venous pressure (JVP). METHODS we used a single crystal ultrasound coupled to a force-sensing load cell to measure JVP based on the force necessary to collapse the internal jugular vein (IJV) walls. We used a gelatin-based model system of the IJV to test the ability of single crystal ultrasound to identify the IJV and verified the cross-sectional position and diameter of the vessels with conventional imaging ultrasound. We also tested our prototype device on healthy human volunteers. RESULTS experiments on model system demonstrated that vessel diameters determined with single crystal ultrasound were in close agreement with the diameters derived from conventional 2-D ultrasound. Proof-of-concept human experiments demonstrate that single crystal ultrasound can detect the IJV in basal and collapsed states, as compared to gold-standard sonography (insert stats). Assessment of JVP in human volunteers was physiologically consistent with and sensitive to postural changes (supine JVP 6.6 ± 2.4 mmHg; standing JVP 4.2 ± 1.9 mmHg (p < 0.0001). CONCLUSION noninvasive assessment of JVP could prove valuable in informing rapid clinical decision-making across various pathologies and conditions leading to derangements in intravascular volume status.
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Xu J, Shaughnessy G, Schafer S, Jiang J, Mistretta C, Strother CM. Assessing the reliability of pulsatility in four-dimensional digital subtraction angiography time concentration curves. Biomed Phys Eng Express 2018. [DOI: 10.1088/2057-1976/aab5e4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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40
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Kaul MG, Salamon J, Knopp T, Ittrich H, Adam G, Weller H, Jung C. Magnetic particle imaging for in vivo blood flow velocity measurements in mice. Phys Med Biol 2018; 63:064001. [PMID: 29465412 DOI: 10.1088/1361-6560/aab136] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Magnetic particle imaging (MPI) is a new imaging technology. It is a potential candidate to be used for angiographic purposes, to study perfusion and cell migration. The aim of this work was to measure velocities of the flowing blood in the inferior vena cava of mice, using MPI, and to evaluate it in comparison with magnetic resonance imaging (MRI). A phantom mimicking the flow within the inferior vena cava with velocities of up to 21 cm s-1 was used for the evaluation of the applied analysis techniques. Time-density and distance-density analyses for bolus tracking were performed to calculate flow velocities. These findings were compared with the calibrated velocities set by a flow pump, and it can be concluded that velocities of up to 21 cm s-1 can be measured by MPI. A time-density analysis using an arrival time estimation algorithm showed the best agreement with the preset velocities. In vivo measurements were performed in healthy FVB mice (n = 10). MRI experiments were performed using phase contrast (PC) for velocity mapping. For MPI measurements, a standardized injection of a superparamagnetic iron oxide tracer was applied. In vivo MPI data were evaluated by a time-density analysis and compared to PC MRI. A Bland-Altman analysis revealed good agreement between the in vivo velocities acquired by MRI of 4.0 ± 1.5 cm s-1 and those measured by MPI of 4.8 ± 1.1 cm s-1. Magnetic particle imaging is a new tool with which to measure and quantify flow velocities. It is fast, radiation-free, and produces 3D images. It therefore offers the potential for vascular imaging.
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Affiliation(s)
- Michael G Kaul
- Department for Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
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Kovarovic B, Woo HH, Fiorella D, Lieber BB, Sadasivan C. Pressure and Flow Rate Changes During Contrast Injections in Cerebral Angiography: Correlation to Reflux Length. Cardiovasc Eng Technol 2018; 9:226-239. [PMID: 29497965 DOI: 10.1007/s13239-018-0344-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 02/22/2018] [Indexed: 10/17/2022]
Abstract
Cerebral angiography involves the antegrade injection of contrast media through a catheter into the vasculature to visualize the region of interest under X-ray imaging. Depending on the injection and blood flow parameters, the bolus of contrast can propagate in the upstream direction and proximal to the catheter tip, at which point contrast is said to have refluxed. In this in vitro study, we investigate the relationship of fundamental hemodynamic variables to this phenomenon. Contrast injections were carried out under steady and pulsatile flow using various vessel diameters, catheter sizes, working fluid flow rates, and injection rates. The distance from the catheter tip to the proximal edge of the contrast bolus, called reflux length, was measured on the angiograms; the relation of this reflux length to different hemodynamic parameters was evaluated. Results show that contrast reflux occurs when the pressure distal to the catheter tip increases to be greater than the pressure proximal to the catheter tip. The ratio of this pressure difference to the baseline flow rate, called reflux resistance here, was linearly correlated to the normalized reflux length (reflux length/vessel diameter). Further, the ratio of blood flow to contrast fluid momentums, called the Craya-Curtet number, was correlated to the normalized reflux length via a sigmoid function. A sigmoid function was also found to be representative of the relationship between the ratio of the Reynolds numbers of blood flow to contrast and the normalized reflux length. As described by previous reports, catheter based contrast injections cause substantial increases in local flow and pressure. Contrast reflux should generally be avoided during standard antegrade angiography. Our study shows two specific correlations between contrast reflux length and baseline and intra-injection parameters that have not been published previously. Further studies need to be conducted to fully characterize the phenomena and to extract reliable indicators of clinical utility. Parameters relevant to cerebral angiography are studied here, but the essential principles are applicable to all angiographic procedures involving antegrade catheter injections.
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Affiliation(s)
- Brandon Kovarovic
- Department of Biomedical Engineering, Stony Brook University, 102 Bioengineering Building, Stony Brook, NY, 11794-5281, USA
| | - Henry H Woo
- Department of Neurological Surgery, Stony Brook University, HSC T-12, Rm 080, Stony Brook, NY, 11794-8122, USA
| | - David Fiorella
- Department of Neurological Surgery, Stony Brook University, HSC T-12, Rm 080, Stony Brook, NY, 11794-8122, USA
| | - Baruch B Lieber
- Department of Biomedical Engineering, Stony Brook University, 102 Bioengineering Building, Stony Brook, NY, 11794-5281, USA.,Department of Neurological Surgery, Stony Brook University, HSC T-12, Rm 080, Stony Brook, NY, 11794-8122, USA
| | - Chander Sadasivan
- Department of Neurological Surgery, Stony Brook University, HSC T-12, Rm 080, Stony Brook, NY, 11794-8122, USA.
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Dholakia RJ, Kappel AD, Pagano A, Woo HH, Lieber BB, Fiorella DJ, Sadasivan C. In vitro angiographic comparison of the flow-diversion performance of five neurovascular stents. Interv Neuroradiol 2017; 24:150-161. [PMID: 29239685 DOI: 10.1177/1591019917748317] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Background and purpose Data differentiating flow diversion properties of commercially available low- and high-porosity stents are limited. This in vitro study applies angiographic analysis of intra-aneurysmal flow to compare the flow-diversion performance of five neurovascular devices in idealized sidewall and bifurcation aneurysm models. Methods Five commercial devices (Enterprise, Neuroform, LVIS, FRED, and Pipeline) were implanted in silicone sidewall and bifurcation aneurysm models under physiological average flow of blood analog fluid. High-speed angiographic images were acquired pre- and post-device implantation and contrast concentration-time curves within the aneurysm were recorded. The curves were quantified with five parameters to assess changes in contrast transport, and thus aneurysm hemodynamics, due to each device. Results Inter-device flow-diversion performance was more easily distinguished in the sidewall model than the bifurcation model. There were no obvious overall statistical trends in the bifurcation parameters but the Pipeline performed marginally better than the other devices. In the sidewall geometry, overall evidence suggests that the LVIS performed better than the Neuroform and Enterprise. The Pipeline and FRED devices were statistically superior to the three stents and Pipeline was superior to FRED in all sidewall parameters evaluated. Conclusions Based on this specific set of experiments, lower-porosity flow diverters perform significantly better in reducing intra-aneurysmal flow activity than higher-porosity stents in sidewall-type geometries. The LVIS device is potentially a better flow diverter than the Neuroform and Enterprise devices, while the Pipeline is potentially better than the FRED.
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Affiliation(s)
- Ronak J Dholakia
- Department of Neurological Surgery, 12301 Stony Brook University , Stony Brook, NY, USA
| | - Ari D Kappel
- Department of Neurological Surgery, 12301 Stony Brook University , Stony Brook, NY, USA
| | - Andrew Pagano
- Department of Neurological Surgery, 12301 Stony Brook University , Stony Brook, NY, USA
| | - Henry H Woo
- Department of Neurological Surgery, 12301 Stony Brook University , Stony Brook, NY, USA
| | - Baruch B Lieber
- Department of Neurological Surgery, 12301 Stony Brook University , Stony Brook, NY, USA
| | - David J Fiorella
- Department of Neurological Surgery, 12301 Stony Brook University , Stony Brook, NY, USA
| | - Chander Sadasivan
- Department of Neurological Surgery, 12301 Stony Brook University , Stony Brook, NY, USA
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Lin CJ, Yang HC, Chien AC, Guo WY, Wu CC, Hung SC, Chen KK, Wu HM, Luo CB, Chu WF, Hong JS, Wu CSF. In-room assessment of intravascular velocity from time-resolved rotational angiography in patients with arteriovenous malformation: a pilot study. J Neurointerv Surg 2017; 10:580-586. [DOI: 10.1136/neurintsurg-2017-013387] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 09/07/2017] [Accepted: 09/10/2017] [Indexed: 11/04/2022]
Abstract
BackgroundTime-resolved rotational angiography (t-RA) enables interventionists to better comprehend complex arteriovenous malformations (AVMs), thereby facilitating endovascular treatment. However, its use in evaluating hemodynamic changes has rarely been explored.ObjectiveThis study uses t-RA to estimate intravascular flow in patients with AVM to compare this with flow in the normal population.MethodsPatients with available t-RA scans were prospectively categorized into one of three groups: hemorrhagic AVM, non-hemorrhagic AVM and control. Pulsatile time–density curves (TDCs) for C1, C6 and VOIMCA were used for amplitude and velocity estimation. C1 was at the cervical internal carotid artery (ICA), 2–3 cm below the carotid canal, C6 was at the paraclinoid segment of the ICA, and VOIMCA was at the junction of the first and second segment of the middle cerebral artery (MCA). A waveform amplitude ratio was defined as (peak − trough)/trough contrast intensity. VICA was defined as the distance between C6 and C1 divided by the time required for the wave to pass, and correspondingly, the average velocity of MCA (VMCA) was defined as the distance between C6 and VOIMCA divided by the duration for the same peak to travel from C6 and VOIMCA, AVM volume was estimated by MR angiography.ResultsAmplitude ratios AC1 and AC6, and average flow velocities VICA and VMCA were significantly larger in the non-hemorrhagic group than in the control group, while the hemorrhagic AVM group was not significantly different from the controls. VICA and VMCA showed moderate to good correlations with AVM volume (r=0.51 and 0.73, respectively). VMCA (33.0±9.1) was significantly lower than VICA (41.3±13.2) in the control group, but not in the two AVM groups.ConclusionTDC waveform propagation derived from t-RA can quantify hemodynamic differences between AVM and the control group. t-RA provides both real-time anatomic and hemodynamic evaluation, and can thus potentially improve the interventional workflow.
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Peri-Therapeutic Quantitative Flow Analysis of Endovascular Revascularization for Ischemic Stroke Patients on Digital Subtraction Angiography. J Med Biol Eng 2017. [DOI: 10.1007/s40846-017-0322-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Lee HJ, Hong JS, Lin CJ, Kao YH, Chang FC, Luo CB, Chu WF. Automatic flow analysis of digital subtraction angiography using independent component analysis in patients with carotid stenosis. PLoS One 2017; 12:e0185330. [PMID: 28949999 PMCID: PMC5614569 DOI: 10.1371/journal.pone.0185330] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 09/11/2017] [Indexed: 11/19/2022] Open
Abstract
PURPOSE Current time-density curve analysis of digital subtraction angiography (DSA) provides intravascular flow information but requires manual vasculature selection. We developed an angiographic marker that represents cerebral perfusion by using automatic independent component analysis. MATERIALS AND METHODS We retrospectively analyzed the data of 44 patients with unilateral carotid stenosis higher than 70% according to North American Symptomatic Carotid Endarterectomy Trial criteria. For all patients, magnetic resonance perfusion (MRP) was performed one day before DSA. Fixed contrast injection protocols and DSA acquisition parameters were used before stenting. The cerebral circulation time (CCT) was defined as the difference in the time to peak between the parietal vein and cavernous internal carotid artery in a lateral angiogram. Both anterior-posterior and lateral DSA views were processed using independent component analysis, and the capillary angiogram was extracted automatically. The full width at half maximum of the time-density curve in the capillary phase in the anterior-posterior and lateral DSA views was defined as the angiographic mean transient time (aMTT; i.e., aMTTAP and aMTTLat). The correlations between the degree of stenosis, CCT, aMTTAP and aMTTLat, and MRP parameters were evaluated. RESULTS The degree of stenosis showed no correlation with CCT, aMTTAP, aMTTLat, or any MRP parameter. CCT showed a strong correlation with aMTTAP (r = 0.67) and aMTTLat (r = 0.72). Among the MRP parameters, CCT showed only a moderate correlation with MTT (r = 0.67) and Tmax (r = 0.40). aMTTAP showed a moderate correlation with Tmax (r = 0.42) and a strong correlation with MTT (r = 0.77). aMTTLat also showed similar correlations with Tmax (r = 0.59) and MTT (r = 0.73). CONCLUSION Apart from vascular anatomy, aMTT estimates brain parenchyma hemodynamics from DSA and is concordant with MRP. This process is completely automatic and provides immediate measurement of quantitative peritherapeutic brain parenchyma changes during stenting.
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Affiliation(s)
- Han-Jui Lee
- Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan
- School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Jia-Sheng Hong
- Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan
| | - Chung-Jung Lin
- Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan
- School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Yi-Hsuan Kao
- Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan
| | - Feng-Chi Chang
- Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan
- School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Chao-Bao Luo
- Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan
- School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Wei-Fa Chu
- Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan
- School of Medicine, National Yang-Ming University, Taipei, Taiwan
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Yang Z, Yu H, Huang GP, Ludwig B. Divergence Compensatory Optical Flow Method for Blood Velocimetry. J Biomech Eng 2017; 139:2621588. [PMID: 28418506 DOI: 10.1115/1.4036484] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Indexed: 11/08/2022]
Abstract
Detailed blood velocity map in the vascular system can be obtained by applying the optical flow method (OFM) in processing fluoroscopic digital subtracted catheter angiographic images; however, there are still challenges with the accuracy of this method. In the present study, a divergence compensatory optical flow method (DC-OFM), in which a nonzero divergence of velocity is assumed due to the finite resolution of the image, was explored and applied to the digital subtraction angiography (DSA) images of blood flow. The objective of this study is to examine the applicability and evaluate the accuracy of DC-OFM in assessing the blood flow velocity in vessels. First, an Oseen vortex flow was simulated on the standard particle image to generate an image pair. Then, the DC-OFM was applied on the particle image pair to recover the velocity field for validation. Second, DSA images of intracranial arteries were used to examine the accuracy of the current method. For each set of images, the first image is the in vivo DSA image, and the second image is generated by superimposing a given flow field. The recovered velocity map by DC-OFM agrees well with the exact velocity for both the particle images and the angiographic images. In comparison with the traditional OFM, the present method can provide more accurate velocity estimation. The accuracy of the velocity estimation can also be improved by implementing preprocess techniques including image intensification, Gaussian filtering, and "image-shift."
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Affiliation(s)
- Zifeng Yang
- Mem. ASME Department of Mechanical and Materials Engineering, Wright State University, 3640 Colonel Glenn Highway, Dayton, OH 45435 e-mail:
| | - Hongtao Yu
- Department of Mechanical and Materials Engineering, Wright State University, Dayton, OH 45435 e-mail:
| | - George P Huang
- Fellow ASME Department of Mechanical and Materials Engineering, Wright State University, Dayton, OH 45435 e-mail:
| | - Bryan Ludwig
- Boonshoft School of Medicine, Wright State University, Dayton, OH 45435;Division of NeuroInterventional Surgery, Department of Neurology, Premier Health-Clinical Neuroscience Institute, Wright State University, 30 E. Apple Street, Dayton, OH 45409 e-mail:
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Treatment Evaluation of Flow-Limiting Stenoses of the Superficial Femoral and Popliteal Artery by Parametric Color-Coding Analysis of Digital Subtraction Angiography Series. Cardiovasc Intervent Radiol 2017; 40:1147-1154. [PMID: 28488106 DOI: 10.1007/s00270-017-1670-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 04/24/2017] [Indexed: 12/16/2022]
Abstract
PURPOSE To evaluate the hemodynamic effect of percutaneous transluminal intervention (PTI) on stenosis of the superficial femoral (SFA) and popliteal arteries (PA) using time-density curves (TDCs) derived from digital subtraction angiography (DSA) series in correlation with ultrasound peak systolic velocity ratio (PSVR) and ankle brachial index (ABI). MATERIALS AND METHODS DSA series of SFA or PA of patients with symptomatic peripheral arterial occlusive disease was obtained with a flat-panel angiography system with intention-to-treat. In DSA series acquired before and after PTI, TDCs were analyzed proximal and distal of each stenosis using parametric color coding (PCC). For correlation, ABI and PSVR measurements pre- and post-PTI were recorded for all patients. RESULTS In total, 25 stenoses of the SFA or PA were treated by PTI in 22 patients (17 male, 5 female, mean age 68 years). After treatment, peak-to-peak (PTP) times between TDCs proximal and distal to the treated vessel segment decreased statistically significantly (p = 0.01) on average from PTP = 1.9 ± 1.7 s to mean PTP = 1 ± 1 s. ABI and PSVR also changed statistically significantly after treatment (pretreatment ABI = 0.7 ± 0.2, PSVR = 4.2 ± 1.9; post-ABI = 0.9 ± 0.2, PSVR = 1.3 ± 0.4, both p < 0.05). Correlation parameters did not show a strong correlation between change in TDC and clinical parameters ABI and PSVR. CONCLUSION Using PCC for analyzing contrast medium dynamics in DSA series is clinically useful for evaluating stenoses of the SFA and PA and for immediate treatment control after PTA. LEVEL OF EVIDENCE Case series, IV.
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Lang JAR, Pearson JT, Binder-Heschl C, Wallace MJ, Siew ML, Kitchen MJ, Te Pas AB, Lewis RA, Polglase GR, Shirai M, Hooper SB. Vagal denervation inhibits the increase in pulmonary blood flow during partial lung aeration at birth. J Physiol 2017; 595:1593-1606. [PMID: 27902842 DOI: 10.1113/jp273682] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Accepted: 11/15/2016] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Lung aeration at birth significantly increases pulmonary blood flow, which is unrelated to increased oxygenation or other spatial relationships that match ventilation to perfusion. Using simultaneous X-ray imaging and angiography in near-term rabbits, we investigated the relative contributions of the vagus nerve and oxygenation to the increase in pulmonary blood flow at birth. Vagal denervation inhibited the global increase in pulmonary blood flow induced by partial lung aeration, although high inspired oxygen concentrations can partially mitigate this effect. The results of the present study indicate that a vagal reflex may mediate a rapid global increase in pulmonary blood flow in response to partial lung aeration. ABSTRACT Air entry into the lungs at birth triggers major cardiovascular changes, including a large increase in pulmonary blood flow (PBF) that is not spatially related to regional lung aeration. To investigate the possible underlying role of a vagally-mediated stimulus, we used simultaneous phase-contrast X-ray imaging and angiography in near-term (30 days of gestation) vagotomized (n = 15) or sham-operated (n = 15) rabbit kittens. Rabbits were imaged before ventilation, when one lung was ventilated (unilateral) with 100% nitrogen (N2 ), air or 100% oxygen (O2 ), and after all kittens were switched to unilateral ventilation in air and then ventilation of both lungs using air. Compared to control kittens, vagotomized kittens had little or no increase in PBF in both lungs following unilateral ventilation when ventilation occurred with 100% N2 or with air. However, relative PBF did increase in vagotomized animals ventilated with 100% O2 , indicating the independent stimulatory effects of local oxygen concentration and autonomic innervation on the changes in PBF at birth. These findings demonstrate that vagal denervation inhibits the previously observed increase in PBF with partial lung aeration, although high inspired oxygen concentrations can partially mitigate this effect.
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Affiliation(s)
- Justin A R Lang
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia
| | - James T Pearson
- Monash Biomedical Imaging Facility and Department of Physiology, Monash University, Melbourne, Australia.,Australian Synchrotron, Melbourne, Australia.,Department of Cardiac Physiology, National Cerebral and Cardiovascular Centre Research Institute, Osaka, Japan
| | - Corinna Binder-Heschl
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia.,Medical University of Graz, Austria
| | - Megan J Wallace
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia
| | - Melissa L Siew
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia
| | - Marcus J Kitchen
- School of Physics and Astronomy, Monash University, Melbourne, Australia
| | - Arjan B Te Pas
- Department of Pediatrics, Leiden University Medical Centre, Leiden, Netherlands
| | - Robert A Lewis
- Medical Imaging and Radiation Sciences, Monash University, Melbourne, Australia.,Department of Medical Imaging, University of Saskatchewan, Saskatoon, Canada
| | - Graeme R Polglase
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia
| | - Mikiyasu Shirai
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Centre Research Institute, Osaka, Japan
| | - Stuart B Hooper
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Australia.,Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia
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49
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Vali A, Abla AA, Lawton MT, Saloner D, Rayz VL. Computational Fluid Dynamics modeling of contrast transport in basilar aneurysms following flow-altering surgeries. J Biomech 2016; 50:195-201. [PMID: 27890537 DOI: 10.1016/j.jbiomech.2016.11.028] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 11/05/2016] [Indexed: 10/20/2022]
Abstract
In vivo measurement of blood velocity fields and flow descriptors remains challenging due to image artifacts and limited resolution of current imaging methods; however, in vivo imaging data can be used to inform and validate patient-specific computational fluid dynamics (CFD) models. Image-based CFD can be particularly useful for planning surgical interventions in complicated cases such as fusiform aneurysms of the basilar artery, where it is crucial to alter pathological hemodynamics while preserving flow to the distal vasculature. In this study, patient-specific CFD modeling was conducted for two basilar aneurysm patients considered for surgical treatment. In addition to velocity fields, transport of contrast agent was simulated for the preoperative and postoperative conditions using two approaches. The transport of a virtual contrast passively following the flow streamlines was simulated to predict post-surgical flow regions prone to thrombus deposition. In addition, the transport of a mixture of blood with an iodine-based contrast agent was modeled to compare and verify the CFD results with X-ray angiograms. The CFD-predicted patterns of contrast flow were qualitatively compared to in vivo X-ray angiograms acquired before and after the intervention. The results suggest that the mixture modeling approach, accounting for the flow rates and properties of the contrast injection, is in better agreement with the X-ray angiography data. The virtual contrast modeling assessed the residence time based on flow patterns unaffected by the injection procedure, which makes the virtual contrast modeling approach better suited for prediction of thrombus deposition, which is not limited to the peri-procedural state.
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Affiliation(s)
- Alireza Vali
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Adib A Abla
- Department of Neurosurgery, University of Arkansas for Medical Science, AR, USA
| | - Michael T Lawton
- Department of Neurological Surgery, University of California, San Francisco, CA, USA
| | - David Saloner
- Department of Radiology and Biomedical Imaging University of California, San Francisco, CA, USA
| | - Vitaliy L Rayz
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, USA; Department of Mechanical Engineering, University of Wisconsin, Milwaukee, WI, USA.
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50
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Quantitative Real-Time Fluoroscopy Analysis on Measurement of the Hepatic Arterial Flow During Transcatheter Arterial Chemoembolization of Hepatocellular Carcinoma: Comparison with Quantitative Digital Subtraction Angiography Analysis. Cardiovasc Intervent Radiol 2016; 39:1557-1563. [DOI: 10.1007/s00270-016-1421-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 07/07/2016] [Indexed: 11/25/2022]
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