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Wise PA, Preukschas AA, Özmen E, Bellemann N, Norajitra T, Sommer CM, Stock C, Mehrabi A, Müller-Stich BP, Kenngott HG, Nickel F. Intraoperative liver deformation and organ motion caused by ventilation, laparotomy, and pneumoperitoneum in a porcine model for image-guided liver surgery. Surg Endosc 2024; 38:1379-1389. [PMID: 38148403 PMCID: PMC10881715 DOI: 10.1007/s00464-023-10612-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 11/26/2023] [Indexed: 12/28/2023]
Abstract
BACKGROUND Image-guidance promises to make complex situations in liver interventions safer. Clinical success is limited by intraoperative organ motion due to ventilation and surgical manipulation. The aim was to assess influence of different ventilatory and operative states on liver motion in an experimental model. METHODS Liver motion due to ventilation (expiration, middle, and full inspiration) and operative state (native, laparotomy, and pneumoperitoneum) was assessed in a live porcine model (n = 10). Computed tomography (CT)-scans were taken for each pig for each possible combination of factors. Liver motion was measured by the vectors between predefined landmarks along the hepatic vein tree between CT scans after image segmentation. RESULTS Liver position changed significantly with ventilation. Peripheral regions of the liver showed significantly higher motion (maximal Euclidean motion 17.9 ± 2.7 mm) than central regions (maximal Euclidean motion 12.6 ± 2.1 mm, p < 0.001) across all operative states. The total average motion measured 11.6 ± 0.7 mm (p < 0.001). Between the operative states, the position of the liver changed the most from native state to pneumoperitoneum (14.6 ± 0.9 mm, p < 0.001). From native state to laparotomy comparatively, the displacement averaged 9.8 ± 1.2 mm (p < 0.001). With pneumoperitoneum, the breath-dependent liver motion was significantly reduced when compared to other modalities. Liver motion due to ventilation was 7.7 ± 0.6 mm during pneumoperitoneum, 13.9 ± 1.1 mm with laparotomy, and 13.5 ± 1.4 mm in the native state (p < 0.001 in all cases). CONCLUSIONS Ventilation and application of pneumoperitoneum caused significant changes in liver position. Liver motion was reduced but clearly measurable during pneumoperitoneum. Intraoperative guidance/navigation systems should therefore account for ventilation and intraoperative changes of liver position and peripheral deformation.
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Affiliation(s)
- Philipp A Wise
- Department of General, Visceral and Transplantation Surgery, Heidelberg University, Im Neuenheimer Feld 420, 69120, Heidelberg, Germany
| | - Anas A Preukschas
- Department of General, Visceral and Transplantation Surgery, Heidelberg University, Im Neuenheimer Feld 420, 69120, Heidelberg, Germany
- Department of General, Visceral and Thoracic Surgery, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany
| | - Emre Özmen
- Department of General, Visceral and Transplantation Surgery, Heidelberg University, Im Neuenheimer Feld 420, 69120, Heidelberg, Germany
| | - Nadine Bellemann
- Department of Diagnostic and Interventional Radiology, Heidelberg University, Im Neuenheimer Feld 420, 69120, Heidelberg, Germany
| | - Tobias Norajitra
- Division of Medical and Biological Informatics, German Cancer Research Center, Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
| | - Christof M Sommer
- Department of Diagnostic and Interventional Radiology, Heidelberg University, Im Neuenheimer Feld 420, 69120, Heidelberg, Germany
| | - Christian Stock
- Institute for Medical Biometry and Informatics, Heidelberg University, Im Neuenheimer Feld 305, 69120, Heidelberg, Germany
| | - Arianeb Mehrabi
- Department of General, Visceral and Transplantation Surgery, Heidelberg University, Im Neuenheimer Feld 420, 69120, Heidelberg, Germany
| | - Beat P Müller-Stich
- Division of Abdominal Surgery, Clarunis-Academic Centre of Gastrointestinal Diseases, St. Clara and University Hospital of Basel, Petersgraben 4, 4051, Basel, Switzerland
| | - Hannes G Kenngott
- Department of General, Visceral and Transplantation Surgery, Heidelberg University, Im Neuenheimer Feld 420, 69120, Heidelberg, Germany
| | - Felix Nickel
- Department of General, Visceral and Transplantation Surgery, Heidelberg University, Im Neuenheimer Feld 420, 69120, Heidelberg, Germany.
- Department of General, Visceral and Thoracic Surgery, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany.
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Subashi E, Feng L, Liu Y, Robertson S, Segars P, Driehuys B, Kelsey CR, Yin FF, Otazo R, Cai J. View-sharing for 4D magnetic resonance imaging with randomized projection-encoding enables improvements of respiratory motion imaging for treatment planning in abdominothoracic radiotherapy. Phys Imaging Radiat Oncol 2023; 25:100409. [PMID: 36655213 PMCID: PMC9841273 DOI: 10.1016/j.phro.2022.12.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 12/24/2022] [Accepted: 12/28/2022] [Indexed: 01/03/2023] Open
Abstract
Background and Purpose The accuracy and precision of radiation therapy are dependent on the characterization of organ-at-risk and target motion. This work aims to demonstrate a 4D magnetic resonance imaging (MRI) method for improving spatial and temporal resolution in respiratory motion imaging for treatment planning in abdominothoracic radiotherapy. Materials and Methods The spatial and temporal resolution of phase-resolved respiratory imaging is improved by considering a novel sampling function based on quasi-random projection-encoding and peripheral k-space view-sharing. The respiratory signal is determined directly from k-space, obviating the need for an external surrogate marker. The average breathing curve is used to optimize spatial resolution and temporal blurring by limiting the extent of data sharing in the Fourier domain. Improvements in image quality are characterized by evaluating changes in signal-to-noise ratio (SNR), resolution, target detection, and level of artifact. The method is validated in simulations, in a dynamic phantom, and in-vivo imaging. Results Sharing of high-frequency k-space data, driven by the average breathing curve, improves spatial resolution and reduces artifacts. Although equal sharing of k-space data improves resolution and SNR in stationary features, phases with large temporal changes accumulate significant artifacts due to averaging of high frequency features. In the absence of view-sharing, no averaging and detection artifacts are observed while spatial resolution is degraded. Conclusions The use of a quasi-random sampling function, with view-sharing driven by the average breathing curve, provides a feasible method for self-navigated 4D-MRI at improved spatial resolution.
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Affiliation(s)
- Ergys Subashi
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, United States
| | - Li Feng
- Biomedical Engineering and Imaging Institute, Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Yilin Liu
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, United States
| | - Scott Robertson
- Medical Physics Graduate Program, Duke University Medical Center, Durham, NC, United States
- Department of Radiology, Duke University Medical Center, Durham, NC, United States
| | - Paul Segars
- Medical Physics Graduate Program, Duke University Medical Center, Durham, NC, United States
- Department of Radiology, Duke University Medical Center, Durham, NC, United States
| | - Bastiaan Driehuys
- Medical Physics Graduate Program, Duke University Medical Center, Durham, NC, United States
- Department of Radiology, Duke University Medical Center, Durham, NC, United States
| | - Christopher R Kelsey
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, United States
| | - Fang-Fang Yin
- Medical Physics Graduate Program, Duke University Medical Center, Durham, NC, United States
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, United States
| | - Ricardo Otazo
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, United States
| | - Jing Cai
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Kowloon, Hong Kong
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Zhang X, Song X, Li G, Duan L, Wang G, Dai G, Song Y, Li J, Bai S. Machine Learning Radiomics Model for External and Internal Respiratory Motion Correlation Prediction in Lung Tumor. Technol Cancer Res Treat 2022; 21:15330338221143224. [PMID: 36476136 PMCID: PMC9742719 DOI: 10.1177/15330338221143224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Objectives: The complexity and specificity of lung tumor motion render it necessary to determine the external and internal correlation individually before applying indirect tumor tracking. However, the correlation cannot be determined from patient respiratory and tumor clinical characteristics before treatment. The purpose of this study is to present a machine learning model for an external/internal correlation prediction that is based on computed tomography (CT) radiomic features. Methods: 4-dimensional computed tomography (4DCT) images of 67 patients were collected retrospectively, and the external/internal correlation of lung tumor was calculated based on Spearman's rank correlation coefficient. Radiomic features were extracted from average intensity projection and the light gradient boosting machine (LightGBM)-based cross-validation (the recursive elimination method) was used for feature selection. The LightGBM framework forecasting models with classification thresholds 0.7, 0.8, and 0.9 are established using stratified 5-fold cross-validation. Model performance was assessed using receiver operating characteristics, sensitivity, and specificity. Results: There were 16, 18, and 13 features selected for models 0.7, 0.8, and 0.9, respectively. Texture features are of great importance in external/internal correlation prediction compared to other features in all models. The sensitivities of the predictions in models 0.7, 0.8, and 0.9 were 0.800 ± 0.126, 0.829 ± 0.140, and 0.864 ± 0.086, respectively. The specificities were 0.771 ± 0.114, 0.936 ± 0.0581, and 0.839 ± 0.101, whereas the area under the curve (AUC) was 0.837, 0.946, and 0.877, respectively. Conclusions: Our findings indicate that radiomics is an effective tool for respiratory motion correlation prediction, which can extract tumor motion characteristics. We proposed a machine learning framework for correlation prediction in the motion management strategy for lung tumor patients.
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Affiliation(s)
- Xiangyu Zhang
- Radiotherapy Physics and Technology Center, Cancer Center, West China Hospital, Sichuan University, Chengdu, China
| | - Xinyu Song
- Radiotherapy Physics and Technology Center, Cancer Center, West China Hospital, Sichuan University, Chengdu, China,Department of Radiation Oncology, Cancer Center, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Guangjun Li
- Radiotherapy Physics and Technology Center, Cancer Center, West China Hospital, Sichuan University, Chengdu, China
| | - Lian Duan
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Guangyu Wang
- Radiotherapy Physics and Technology Center, Cancer Center, West China Hospital, Sichuan University, Chengdu, China
| | - Guyu Dai
- Radiotherapy Physics and Technology Center, Cancer Center, West China Hospital, Sichuan University, Chengdu, China
| | - Ying Song
- Radiotherapy Physics and Technology Center, Cancer Center, West China Hospital, Sichuan University, Chengdu, China
| | - Jing Li
- Radiotherapy Physics and Technology Center, Cancer Center, West China Hospital, Sichuan University, Chengdu, China
| | - Sen Bai
- Radiotherapy Physics and Technology Center, Cancer Center, West China Hospital, Sichuan University, Chengdu, China,Department of Radiation Oncology, Cancer Center, West China Hospital, Sichuan University, Chengdu, China,Sen Bai, MS, Radiotherapy Physics and Technology Center, Cancer Center, West China Hospital, Sichuan University, Chengdu, China.
Guangjun Li, MS, Radiotherapy Physics and Technology Center, Cancer Center, West China Hospital, Sichuan University, Chengdu, China.
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Curcuru AN, Kim T, Yang D, Gach HM. Real-time B 0 compensation during gantry rotation in a 0.35 T MRI-Linac. Med Phys 2022; 49:6451-6460. [PMID: 35906957 DOI: 10.1002/mp.15892] [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: 03/22/2022] [Revised: 07/06/2022] [Accepted: 07/24/2022] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Rotation of the ferromagnetic gantry of a low magnetic field MRI-Linac was previously demonstrated to cause large center frequency offsets of ±400 Hz. The B0 off-resonances cause image artifacts and imaging isocenter shifts that would preclude MRI-guided arc therapy. PURPOSE The purpose of this study was to measure and compensate for center frequency offsets in real-time during gantry rotation on a 0.35 T MRI-Linac using a free induction decay (FID) navigator. METHODS A nonselective FID navigator was added before each 2D balanced steady-state free precession (bSSFP) cine image acquisition on a 0.35 T MRI-Linac. Images were acquired at 7.3 frames per second. Phase data from the initial FID navigator (while the gantry was stationary) was used as a reference. The phase data from each subsequent FID navigator was used to calculate the real-time B0 off-resonance. The transmitter/receiver phase and the phase accrual over the adjacent image acquisition were adjusted to correct for the center frequency offset. Measurements were performed using a MRI-Linac dynamic phantom prior to and while the gantry rotated clockwise and counterclockwise. Image quality and signal-to-noise ratio were compared between uncorrected and B0 corrected MRIs using a reference image acquired while the gantry was stationary. Four targets in the phantom were manually contoured on the first image frame and an active contouring algorithm was used retrospectively on each subsequent frame to assess image variations and calculate Dice coefficients. Additionally, three healthy volunteers were imaged using the same pulse sequences with and without real-time B0 compensation during gantry rotation. Normalized root mean square errors (nRMSEs) were calculated for the phantom and in vivo to assess the efficacy of the B0 compensation on image quality. The measured center frequency offsets from the volunteer and MRI dynamic phantom navigator data were also compared. The sinusoidal behavior of the center frequency offsets was modeled based on the gantry layout and long time constant eddy currents resulting from gantry rotation. RESULTS The duration of the FID navigator and processing was 4.5 ms. The FID navigator resulted in a ≤11% drop in signal-to-noise ratio (SNR) in the phantom and in vivo (liver). Dice coefficients from the MR-IGRT phantom contour measurements remained above 0.8 with B0 compensation. Without B0 compensation, the Dice coefficients dropped below 0.8 for up to 21% of the time depending on the contour. Real-time B0 compensation resulted in mean reductions in nRMSE of 51% and 16% for the MR-IGRT phantom and in vivo, respectively. Peak-to-peak center frequency offsets ranged from 757 to 773 Hz in the phantom and 670 to 871 Hz in vivo. CONCLUSION Dynamic real-time B0 compensation significantly improved image quality and reduced artifacts during gantry rotation in the phantom and in vivo. However, the FID navigator resulted in a small drop in the imaging duty cycle and SNR. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Austen N Curcuru
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri, 63110, USA
| | - Taeho Kim
- Department of Radiation Oncology, Washington University in St. Louis, St. Louis, Missouri, 63110, USA
| | - Deshan Yang
- Departments of Radiation Oncology and Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri, 63110, USA
| | - H Michael Gach
- Departments of Radiation Oncology, Radiology, and Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri, 63110, USA
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Dimov IP, Tous C, Li N, Barat M, Bomberna T, Debbaut C, Jin N, Moran G, Tang A, Soulez G. Assessment of hepatic arterial hemodynamics with 4D flow MRI: in vitro analysis of motion and spatial resolution related error and in vivo feasibility study in 20 volunteers. Eur Radiol 2022; 32:8639-8648. [PMID: 35731288 DOI: 10.1007/s00330-022-08890-5] [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: 01/25/2022] [Revised: 04/25/2022] [Accepted: 05/17/2022] [Indexed: 11/30/2022]
Abstract
OBJECTIVES To assess the ability of four-dimensional (4D) flow MRI to measure hepatic arterial hemodynamics by determining the effects of spatial resolution and respiratory motion suppression in vitro and its applicability in vivo with comparison to two-dimensional (2D) phase-contrast MRI. METHODS A dynamic hepatic artery phantom and 20 consecutive volunteers were scanned. The accuracies of Cartesian 4D flow sequences with k-space reordering and navigator gating at four spatial resolutions (0.5- to 1-mm isotropic) and navigator acceptance windows (± 8 to ± 2 mm) and one 2D phase-contrast sequence (0.5-mm in -plane) were assessed in vitro at 3 T. Two sequences centered on gastroduodenal and hepatic artery branches were assessed in vivo for intra - and interobserver agreement and compared to 2D phase-contrast. RESULTS In vitro, higher spatial resolution led to a greater decrease in error than narrower navigator window (30.5 to -4.67% vs -6.64 to -4.67% for flow). In vivo, hepatic and gastroduodenal arteries were more often visualized with the higher resolution sequence (90 vs 71%). Despite similar interobserver agreement (κ = 0.660 and 0.704), the higher resolution sequence had lower variability for area (CV = 20.04 vs 30.67%), flow (CV = 34.92 vs 51.99%), and average velocity (CV = 26.47 vs 44.76%). 4D flow had lower differences between inflow and outflow at the hepatic artery bifurcation (11.03 ± 5.05% and 15.69 ± 6.14%) than 2D phase-contrast (28.77 ± 21.01%). CONCLUSION High-resolution 4D flow can assess hepatic artery anatomy and hemodynamics with improved accuracy, greater vessel visibility, better interobserver reliability, and internal consistency. KEY POINTS • Motion-suppressed Cartesian four-dimensional (4D) flow MRI with higher spatial resolution provides more accurate measurements even when accepted respiratory motion exceeds voxel size. • 4D flow MRI with higher spatial resolution provides substantial interobserver agreement for visualization of hepatic artery branches. • Lower peak and average velocities and a trend toward better internal consistency were observed with 4D flow MRI as compared to 2D phase-contrast.
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Affiliation(s)
- Ivan P Dimov
- Laboratory of Clinical Image Processing (LCTI), Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900, rue Saint-Denis, Pavillon R, Montreal, QC, H2X 0A9, Canada
| | - Cyril Tous
- Laboratory of Clinical Image Processing (LCTI), Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900, rue Saint-Denis, Pavillon R, Montreal, QC, H2X 0A9, Canada
| | - Ning Li
- Laboratory of Clinical Image Processing (LCTI), Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900, rue Saint-Denis, Pavillon R, Montreal, QC, H2X 0A9, Canada
| | - Maxime Barat
- Laboratory of Clinical Image Processing (LCTI), Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900, rue Saint-Denis, Pavillon R, Montreal, QC, H2X 0A9, Canada.,Department of Radiology and Nuclear Medicine, Centre Hospitalier de l'Université de Montréal (CHUM), Montreal, QC, Canada
| | - Tim Bomberna
- IBiTech-Biommeda, Department of Electronics and Information Systems, Ghent University, Ghent, Belgium.,Cancer Research Institute Ghent (CRIG), Ghent University, Ghent, Belgium
| | - Charlotte Debbaut
- IBiTech-Biommeda, Department of Electronics and Information Systems, Ghent University, Ghent, Belgium.,Cancer Research Institute Ghent (CRIG), Ghent University, Ghent, Belgium
| | - Ning Jin
- Cardiovascular MR R&D, Siemens Medical Solutions USA, Inc., Cleveland, OH, USA
| | - Gerald Moran
- Siemens Healthineers Canada, Oakville, ON, Canada
| | - An Tang
- Laboratory of Clinical Image Processing (LCTI), Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900, rue Saint-Denis, Pavillon R, Montreal, QC, H2X 0A9, Canada.,Department of Radiology and Nuclear Medicine, Centre Hospitalier de l'Université de Montréal (CHUM), Montreal, QC, Canada.,Department of Radiology, Radiation Oncology and Nuclear Medicine, Faculty of Medecine, Université de Montréal, 2900 Bd Edouard-Montpetit , Montreal, QC, H3T 1J4, Canada
| | - Gilles Soulez
- Laboratory of Clinical Image Processing (LCTI), Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900, rue Saint-Denis, Pavillon R, Montreal, QC, H2X 0A9, Canada. .,Department of Radiology and Nuclear Medicine, Centre Hospitalier de l'Université de Montréal (CHUM), Montreal, QC, Canada. .,Department of Radiology, Radiation Oncology and Nuclear Medicine, Faculty of Medecine, Université de Montréal, 2900 Bd Edouard-Montpetit , Montreal, QC, H3T 1J4, Canada.
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Sun JC, Hsieh BT, Hsieh CM, Tsang YW, Cheng KY. Applying the N-isopropylacrylamide gel dosimeter to quantify dynamic dose effects: A feasibility study. Technol Health Care 2022; 30:413-424. [PMID: 35124616 PMCID: PMC9028750 DOI: 10.3233/thc-thc228038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND: The gel dosimeter is a chemical as well as a relative dosimeter. OBJECTIVE: To evaluate the feasibility of using N-isopropylacrylamide (NIPAM) gel dosimeter to observe the dynamic dose effects and quantification of the respiration, and to help determine the safety margins. METHODS: The NIPAM gel dosimeter combined with the dynamic phantom was used to simulate radiotherapy of lung or upper abdominal tumor. The field set to 4 × 5 cm2, simulate respiratory rate of 4 sec/cycle, and motion range 2 cm. MRI was used for reading, and MATLAB was used for analysis. The 3%/3 mm gamma passing rate > 95% was used as a clinical basis for evaluation. RESULTS: The dynamic dose curve was compared with 4 × 5, 4 × 4, 4 × 3 cm2 TPS, and gamma passing rates were 74.32%, 54.83%, 30.18%. Gamma mapping demonstrated that the highest dose region was similar to the result of the 4 × 4 cm2 TPS. After appropriate selection and comparing that the ⩾ 60% part of the dose curve with TPS, the gamma passing rate was 96.49%. CONCLUSIONS: Using the NIPAM gel dosimeter with dynamic phantom to simulate organ motion during respiration for dynamic dose measurement and quantified the dynamic dose effect is feasible. The results are consistent with clinical evaluation standards.
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Affiliation(s)
- Jung-Chang Sun
- Department of Radiation Oncology, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi, Taiwan
- Department of Medical Imaging and Radiological Sciences, Central Taiwan University of Science and Technology, Taichung, Taiwan
| | - Bor-Tsung Hsieh
- Department of Medical Imaging and Radiological Sciences, Central Taiwan University of Science and Technology, Taichung, Taiwan
| | - Chih-Ming Hsieh
- Department of Medical Imaging, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi, Taiwan
| | - Yuk-Wah Tsang
- Department of Radiation Oncology, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi, Taiwan
- Department of Biomedical Engineering, Chung Yuan Christian University, Taoyuan, Taiwan
| | - Kai-Yuan Cheng
- Department of Medical Imaging and Radiological Sciences, Central Taiwan University of Science and Technology, Taichung, Taiwan
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Sun JC, Hsieh BT, Cheng CW, Hsieh CM, Tsang YW, Cheng KY. Using NIPAM gel dosimeter and concentric swing machine to simulate the dose distribution during breathing: A feasibility study. Technol Health Care 2022; 30:123-133. [PMID: 35124590 PMCID: PMC9028686 DOI: 10.3233/thc-228012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND: Radiotherapy plays an important role in cancer treatment today. Successful radiotherapy includes precise positioning and accurate dosimetry. OBJECTIVE: To use NIPAM gel dosimeter and concentric swing machine to simulate and evaluate the feasibility of lung or upper abdominal tumor dose distribution during breathing. METHODS: We used a concentric swing machine to simulate actual radiotherapy for lung or upper abdomen tumors. A 4 × 4 cm2 irradiation field area was set and MRI was performed. Next, readout analysis was performed using MATLAB and the 3 mm, 3% gamma passing rate > 95% was used as a basis for evaluation. RESULTS: The concentric dynamic dose curve for a simulated respiratory rate of 3 seconds/breath and 4 × 4 cm2 field was compared with 4 × 4, 3 × 3, and 2 × 2 cm2 treatment planning systems (TPS), and the 3 mm, 3% gamma passing rate was 42.87%, 54.96%, and 49.92%, respectively. Pre-simulation showed that the high-dose region dose curve was similar to the 2 × 2 cm2 TPS result. After appropriate selection and comparison, we found that the 3 mm, 3% gamma passing rate was 97.92% on comparing the > 60% dose curve with the 2 × 2 cm2 TPS. CONCLUSIONS: NIPAM gel dosimeter and concentric swing machine use is feasible to simulate dose distribution during breathing and results conforming to clinical evaluation standards.
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Affiliation(s)
- Jung-Chang Sun
- Department of Radiation Oncology, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi, Taiwan
- Department of Medical Imaging and Radiological Sciences, Central Taiwan University of Science and Technology, Taichung, Taiwan
| | - Bor-Tsung Hsieh
- Department of Medical Imaging and Radiological Sciences, Central Taiwan University of Science and Technology, Taichung, Taiwan
| | - Chih-Wu Cheng
- Department of Radiation Oncology, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi, Taiwan
| | - Chih-Ming Hsieh
- Department of Medical Imaging, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi, Taiwan
| | - Yuk-Wah Tsang
- Department of Radiation Oncology, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi, Taiwan
- Department of Biomedical Engineering, Chung Yuan Christian University, Taoyuan, Taiwan
| | - Kai-Yuan Cheng
- Department of Medical Imaging and Radiological Sciences, Central Taiwan University of Science and Technology, Taichung, Taiwan
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Cha J, Kim J, Ko J, Kim J, Eom K. Effects of Confounding Factors on Liver Stiffness in Two-Dimensional Shear Wave Elastography in Beagle Dogs. Front Vet Sci 2022; 9:827599. [PMID: 35155659 PMCID: PMC8830801 DOI: 10.3389/fvets.2022.827599] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 01/06/2022] [Indexed: 12/12/2022] Open
Abstract
Background Two-dimensional shear wave elastography (2D-SWE) is a powerful technique that can non-invasively measure liver stiffness to assess hepatic fibrosis. Purpose This study aimed to identify the effects of confounding factors, including anesthesia, breathing, and scanning approach, on liver stiffness when performing 2D-SWE in dogs. Materials and Methods Nine healthy Beagle dogs were included in this study. Hepatic 2D-SWE was performed, and liver stiffness was compared between conscious and anesthetized states, free-breathing and breath-holding conditions, and intercostal and subcostal approaches. For the anesthetized state, the breath-holding condition was subdivided into seven phases, which included forced-expiration (5 and 10 mL/kg), end-expiration (0 cm H2O), and forced-inspiration (5, 10, 15, and 20 cm H2O), and liver stiffness was compared among these phases. Changes in liver stiffness were compared between intercostal and subcostal approaches according to breathing phases. Results No significant difference was observed in liver stiffness between the conscious and anesthetized states or between the free-breathing and breath-holding conditions. No significant difference was noted in liver stiffness among the breathing phases, except for forced-inspiration with high airway pressure (15 and 20 cm H2O in the intercostal approach and 10, 15, and 20 cm H2O in the subcostal approach), which was associated with significantly higher liver stiffness (p < 0.05). Liver stiffness was significantly higher in the subcostal approach than in the intercostal approach (p < 0.05). Changes in liver stiffness were significantly higher in the subcostal approach than in the intercostal approach in all forced-inspiratory phases (p < 0.05). Conclusion In conclusion, when performing 2D-SWE in dogs, liver stiffness is unaffected by anesthesia and free-breathing. To avoid inadvertent increases in liver stiffness, the deep inspiratory phase and subcostal approach are not recommended. Thus, liver stiffness should be interpreted considering these confounding factors.
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Modeling of Tumor Control Probability in Stereotactic Body Radiation Therapy for Adrenal Tumors. Int J Radiat Oncol Biol Phys 2021; 110:217-226. [PMID: 33864824 DOI: 10.1016/j.ijrobp.2020.05.062] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 05/30/2020] [Indexed: 02/08/2023]
Abstract
PURPOSE Stereotactic body radiation therapy (SBRT) in the management of adrenal metastases is emerging as a well-tolerated, effective method of treatment for patients with limited metastatic disease. SBRT planning and treatment utilization are widely variable, and publications report heterogeneous radiation dose fractionation schemes and treatment outcomes. The objective of this analysis was to review the current literature on SBRT for adrenal metastases and to develop treatment guidelines and a model for tumor control probability of SBRT for adrenal metastases based on these publications. METHODS AND MATERIALS A literature search of all studies on SBRT for adrenal metastases published from 2008 to 2017 was performed, and outcomes in these studies were reviewed. Local control (LC) rates were fit to a statistically significant Poisson model using maximum likelihood estimation techniques. RESULTS One-year LC greater than 95% was achieved at an approximated biological equivalent dose with α/β = 10 Gy of 116.4 Gy. CONCLUSIONS While respecting normal tissue tolerances, tumor doses greater than or equal to a biological equivalent dose with α/β = 10 Gy of 116.4 Gy are recommended to achieve high LC. Further studies following unified reporting standards are needed for more robust prediction.
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10
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Kobayashi N. Magnetic resonance imaging with gradient sound respiration guide. PLoS One 2021; 16:e0254758. [PMID: 34280236 PMCID: PMC8289037 DOI: 10.1371/journal.pone.0254758] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 07/03/2021] [Indexed: 12/31/2022] Open
Abstract
Respiratory motion management is crucial for high-resolution MRI of the heart, lung, liver and kidney. In this article, respiration guide using acoustic sound generated by pulsed gradient waveforms was introduced in the pulmonary ultrashort echo time (UTE) sequence and validated by comparing with retrospective respiratory gating techniques. The validated sound-guided respiration was implemented in non-contrast enhanced renal angiography. In the sound-guided respiration, breathe−in and–out instruction sounds were generated with sinusoidal gradient waveforms with two different frequencies (602 and 321 Hz). Performance of the sound-guided respiration was evaluated by measuring sharpness of the lung-liver interface with a 10–90% rise distance, w10-90, and compared with three respiratory motion managements in a free-breathing UTE scan: without respiratory gating (w/o gating), 0-dimensional k-space navigator (k-point navigator), and image-based self-gating (Img-SG). The sound-guided respiration was implemented in stack-of-stars balanced steady-state free precession with inversion recovery preparation for renal angiography. No subjects reported any discomfort or inconvenience with the sound-guided respiration in pulmonary or renal MRI scans. The lung-liver interface of the UTE images for sound-guided respiration (w10-90 = 6.99 ± 2.90 mm), k-point navigator (8.51 ± 2.71 mm), and Img-SG (7.01 ± 2.06 mm) was significantly sharper than that for w/o gating (17.13 ± 2.91 mm; p < 0.0001 for all of sound-guided respiration, k-point navigator and Img-SG). Sharpness of the lung-liver interface was comparable between sound-guided respiration and Img-SG (p = 0.99), but sound-guided respiration achieved better visualization of pulmonary vasculature. Renal angiography with the sound-guided respiration clearly delineated renal, segmental and interlobar arteries. In conclusion, the gradient sound guided respiration can facilitate a consistent diaphragm position in every breath and achieve performance of respiratory motion management comparable to image-based self-gating.
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Affiliation(s)
- Naoharu Kobayashi
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, United States of America
- * E-mail:
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11
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Liu L, Johansson A, Cao Y, Kashani R, Lawrence TS, Balter JM. Modeling intra-fractional abdominal configuration changes using breathing motion-corrected radial MRI. Phys Med Biol 2021; 66. [PMID: 33725676 DOI: 10.1088/1361-6560/abef42] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 03/16/2021] [Indexed: 12/11/2022]
Abstract
Abdominal organ motions introduce geometric uncertainties to gastrointestinal radiotherapy. This study investigated slow drifting motion induced by changes of internal anatomic organ arrangements using a 3D radial MRI sequence with a scan length of 20 min. Breathing motion and cyclic GI motion were first removed through multi-temporal resolution image reconstruction. Slow drifting motion analysis was performed using an image time series consisting of 72 image volumes with a temporal sampling rate of 17 s. B-spline deformable registration was performed to align image volumes of the time series to a reference volume. The resulting deformation fields were used for motion velocity evaluation and patient-specific motion model construction through principal component analysis (PCA). Geometric uncertainties introduced by slow drifting motion were assessed by Hausdorff distances between unions of organs at risk (OARs) at different motion states and reference OAR contours as well as probabilistic distributions of OARs predicted using the PCA model. Thirteen examinations from 11 patients were included in this study. The averaged motion velocities ranged from 0.8 to 1.9 mm min-1, 0.7 to 1.6 mm min-1, 0.6 to 2.0 mm min-1and 0.7 to 1.4 mm min-1for the small bowel, colon, duodenum and stomach respectively; the averaged Hausdorff distances were 5.6 mm, 5.3 mm, 5.1 mm and 4.6 mm. On average, a margin larger than 4.5 mm was needed to cover a space with OAR occupancy probability higher than 55%. Temporal variations of geometric uncertainties were evaluated by comparing across four 5 min sub-scans extracted from the full scan. Standard deviations of Hausdorff distances across sub-scans were less than 1 mm for most examinations, indicating stability of relative margin estimates from separate time windows. These results suggested slow drifting motion of GI organs is significant and geometric uncertainties introduced by such motion should be accounted for during radiotherapy planning and delivery.
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Affiliation(s)
- Lianli Liu
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI 48109, United States of America.,Department of Radiation Oncology, Stanford University, Palo Alto, CA 94304, United States of America
| | - Adam Johansson
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI 48109, United States of America.,Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, SE 75185, Sweden.,Department of Surgical Sciences, Uppsala University, Uppsala, SE 75185, Sweden
| | - Yue Cao
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI 48109, United States of America.,Department of Radiology, University of Michigan, Ann Arbor, MI 48109, United States of America.,Department of biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Rojano Kashani
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - Theodore S Lawrence
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI 48109, United States of America
| | - James M Balter
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI 48109, United States of America
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12
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Sasaki M, Ikushima H, Sakuragawa K, Yokoishi M, Tsuzuki A, Sugimoto W. Determination of reproducibility of end-exhaled breath-holding in stereotactic body radiation therapy. JOURNAL OF RADIATION RESEARCH 2020; 61:977-984. [PMID: 32930802 PMCID: PMC7674682 DOI: 10.1093/jrr/rraa079] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 07/13/2020] [Indexed: 06/11/2023]
Abstract
Methods to evaluate the positional reproducibility of breath-hold irradiation mostly require manual operation. The purpose of this study is to propose a method to determine the reproducibility of breath-hold irradiation of lung tumors between fractions using non-artificial methods. This study included 13 patients who underwent terminal exhaled breath-hold irradiation for primary and metastatic lung cancer. All subjects received a prescribed dose of 60 Gy/8 fractions. The contours of the gross tumor volume (GTV) were extracted by threshold processing using treatment-planning computed tomography (CT) and cone-beam CT (CBCT), which was done just before the beginning of the treatment. The method proposed in this study evaluates the dice similarity coefficient (DSC) and Hausdorff distance (HD) by comparing two volumes, the GTVCTS (GTV obtained from treatment-planning CT) and GTVCBCT (GTV obtained from CBCT). The reference contours for DSC and HD are represented by GTVCTS. The results demonstrated good visual agreement for cases with a DSC of ~0.7. However, apparent misalignment occurred when the DSC was <0.5. HD was >2 mm in 3 out of 13 cases, and when the DSC was ~0.7, the HD was ~1 mm. In addition, cases with greater HD also demonstrated more significant variability. It was found that the DSC and HD evaluation methods for the positional reproducibility of breath-hold irradiation proposed in this study are straightforward and can be performed without the involvement of humans. Our study is of extreme significance in the field of radiation studies.
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Affiliation(s)
- Motoharu Sasaki
- Corresponding author. Department of Therapeutic Radiology, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto-cho, Tokushima, Tokushima 770-8503, Japan. Tel: +81-88-633-9053; Fax: +81-88-633-9051;
| | - Hitoshi Ikushima
- Department of Therapeutic Radiology, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto-cho, Tokushima, Tokushima 770-8503, Japan
| | - Kanako Sakuragawa
- Department of Radiological Technology, Tokushima University Hospital, 2-50-1 Kuramoto-cho, Tokushima, Tokushima 770-8503, Japan
| | - Michihiro Yokoishi
- Department of Radiological Technology, Tokushima University Hospital, 2-50-1 Kuramoto-cho, Tokushima, Tokushima 770-8503, Japan
| | - Akira Tsuzuki
- Department of Radiological Technology, Kochi Medical School Hospital, 185-1 Kohasu, Oko-cho, Nankoku-shi, Kochi 783-8505, Japan
| | - Wataru Sugimoto
- Department of Radiological Technology, Tokushima Prefectural Central Hospital, 1-10-3 Kuramoto-cho, Tokushima, Tokushima 770-8539, Japan
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13
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Guo R, Cai X, Kucukseymen S, Rodriguez J, Paskavitz A, Pierce P, Goddu B, Thompson RB, Nezafat R. Free-breathing simultaneous myocardial T 1 and T 2 mapping with whole left ventricle coverage. Magn Reson Med 2020; 85:1308-1321. [PMID: 33078443 DOI: 10.1002/mrm.28506] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 08/13/2020] [Accepted: 08/14/2020] [Indexed: 01/20/2023]
Abstract
PURPOSE To develop a free-breathing sequence, that is, Multislice Joint T1 -T2 , for simultaneous measurement of myocardial T1 and T2 for multiple slices to achieve whole left-ventricular coverage. METHODS Multislice Joint T1 -T2 adopts slice-interleaved acquisition to collect 10 single-shot electrocardiogram-triggered images for each slice prepared by saturation and T2 preparation to simultaneously estimate myocardial T1 and T2 and achieve whole left-ventricular coverage. Prospective slice-tracking using a respiratory navigator and retrospective image registration are used to reduce through-plane and in-plane motion, respectively. Multislice Joint T1 -T2 was validated through numerical simulations and phantom and in vivo experiments, and compared with saturation-recovery single-shot acquisition and T2 -prepared balanced Steady-State Free Precession (T2 -prep SSFP) sequences. RESULTS Phantom T1 and T2 from Multislice Joint T1 -T2 had good accuracy and precision, and were insensitive to heart rate. Multislice Joint T1 -T2 yielded T1 and T2 maps of nine left-ventricular slices in 1.4 minutes. The mean left-ventricular T1 difference between saturation-recovery single-shot acquisition and Multislice Joint T1 -T2 across healthy subjects and patients was 191 ms (1564 ± 60 ms versus 1373 ± 50 ms; P < .05) and 111 ms (1535 ± 49 ms vs 1423 ± 49 ms; P < .05), respectively. The mean difference in left-ventricular T2 between T2 -prep SSFP and Multislice Joint T1 -T2 across healthy subjects and patients was -6.3 ms (42.4 ± 1.4 ms vs 48.7 ± 2.5; P < .05) and -5.7 ms (41.6 ± 2.5 ms vs 47.3 ± 2.7; P < .05), respectively. CONCLUSION Multislice Joint T1 -T2 enables quantification of whole left-ventricular T1 and T2 during free breathing within a clinically feasible scan time of less than 2 minutes.
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Affiliation(s)
- Rui Guo
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Xiaoying Cai
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA.,Siemens Medical Solutions USA, Inc., Boston, Massachusetts, USA
| | - Selcuk Kucukseymen
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Jennifer Rodriguez
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Amanda Paskavitz
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Patrick Pierce
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Beth Goddu
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Richard B Thompson
- Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - Reza Nezafat
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
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14
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Guo R, Cai X, Kucukseymen S, Rodriguez J, Paskavitz A, Pierce P, Goddu B, Nezafat R. Free-breathing whole-heart multi-slice myocardial T 1 mapping in 2 minutes. Magn Reson Med 2020; 85:89-102. [PMID: 32662908 DOI: 10.1002/mrm.28402] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 05/13/2020] [Accepted: 06/08/2020] [Indexed: 12/26/2022]
Abstract
PURPOSE To develop and validate a saturation-delay-inversion recovery preparation, slice tracking and multi-slice based sequence for measuring whole-heart native T1 . METHOD The proposed free-breathing sequence performs T1 mapping of multiple left-ventricular slices by slice-interleaved acquisition to collect 10 electrocardiogram-triggered single-shot slice-selective images for each slice. A saturation-delay-inversion recovery pulse is used for T1 preparation. Prospective slice tracking by the diaphragm navigator and retrospective registration are used to reduce through-plane and in-plane motion, respectively. The proposed sequence was validated in both phantom and human subjects (12 healthy subjects and 15 patients who were referred for a clinical cardiac MR exam) and compared with saturation recovery single-shot acquisition (SASHA) and modified Look-Locker inversion recovery (MOLLI). RESULTS Phantom T1 measured by the proposed sequence had excellent agreement (R2 = 0.99) with the ground-truth T1 and was insensitive to heart rate. In both healthy subjects and patients, the proposed sequence yielded nine left-ventricular T1 maps per volume in less than 2 minutes (healthy volunteers: 1.8 ± 0.4 minutes; patients: 1.9 ± 0.2 minutes). The average T1 of whole left ventricle for all healthy subjects and patients were 1560 ± 61 and 1535 ± 49 ms by SASHA, 1208 ± 42 and 1233 ± 56 ms by MOLLI5(3)3, and 1397 ± 34 and 1433 ± 56 ms by the proposed sequence, respectively. The corresponding coefficient of variation of T1 were 6.2 ± 1.4% and 5.8 ± 1.6%, 5.3 ± 1.1% and 5.1 ± 0.8%, and 4.9 ± 0.8% and 4.5 ± 0.8%, respectively. CONCLUSION The proposed sequence enables quantification of whole heart T1 with good accuracy and precision in less than 2 minutes during free breathing.
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Affiliation(s)
- Rui Guo
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - Xiaoying Cai
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.,Siemens Medical Solutions USA, Inc., Boston, MA, USA
| | - Selcuk Kucukseymen
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - Jennifer Rodriguez
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - Amanda Paskavitz
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - Patrick Pierce
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - Beth Goddu
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - Reza Nezafat
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
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15
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Lee JH, Lee SM, Yoon JH, Kim MJ, Ha HI, Park SJ, Kim ES, Lee K, Lee JM. Impact of respiratory motion on liver stiffness measurements according to different shear wave elastography techniques and region of interest methods: a phantom study. Ultrasonography 2020; 40:103-114. [PMID: 32447879 PMCID: PMC7758106 DOI: 10.14366/usg.19079] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 04/12/2020] [Indexed: 12/31/2022] Open
Abstract
Purpose This study quantified the impact of respiratory motion on liver stiffness measurements according to different shear wave elastography (SWE) techniques and region of interest (ROI) methods, using liver fibrosis phantoms. Methods Three operators measured stiffness values in four phantoms with different stiffness on a moving platform with two SWE techniques (point-SWE [pSWE] and 2-dimensional SWE [2D-SWE]), three types of motion (static mode and moving mode at low and high speeds), and four ROI methods in 2D-SWE (circle, point, box, and multiple). The circular ROI method was used to compare the two SWE techniques. The occurrence of technical failure and unreliable measurements, stiffness values, and measurement time were evaluated. Results Technical failure was observed only in moving mode for pSWE and 2D-SWE (n=1 for both). Unreliable measurements were also only observed in moving mode and were significantly less common in 2D-SWE (n=1) than in pSWE (n=12) (P<0.001). No statistically significant differences in the technical failure rate or stiffness values were noted between the static and moving modes for both SWE techniques. The technical failure and unreliable measurement rates were not significantly different among the ROI methods for 2D-SWE. Stiffness values did not differ significantly according to the ROI method used in any moving mode. However, the multiple ROI method had significantly shorter measurement times than the circular ROI method for all moving modes. Conclusion 2D-SWE may be preferable for evaluating liver fibrosis in patients with poor breath-hold. Furthermore, 2D-SWE with multiple ROIs enables rapid measurements, without affecting liver stiffness values.
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Affiliation(s)
- Jee Hyeon Lee
- Department of Radiology, Hallym University Sacred Heart Hospital, Anyang, Korea
| | - Sang Min Lee
- Department of Radiology, Hallym University Sacred Heart Hospital, Anyang, Korea
| | - Jeong Hee Yoon
- Department of Radiology, Seoul National University Hospital, Seoul, Korea.,Department of Radiology, Seoul National University College of Medicine, Seoul, Korea
| | - Min-Jeong Kim
- Department of Radiology, Hallym University Sacred Heart Hospital, Anyang, Korea
| | - Hong Il Ha
- Department of Radiology, Hallym University Sacred Heart Hospital, Anyang, Korea
| | - Sung-Joon Park
- Department of Radiology, Korea University Ansan Hospital, Ansan, Korea
| | - Eun Soo Kim
- Department of Radiology, Hallym University Sacred Heart Hospital, Anyang, Korea
| | - Kwanseop Lee
- Department of Radiology, Hallym University Sacred Heart Hospital, Anyang, Korea
| | - Jeong Min Lee
- Department of Radiology, Seoul National University Hospital, Seoul, Korea.,Department of Radiology, Seoul National University College of Medicine, Seoul, Korea.,Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea
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16
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Yoshimura Y, Suzuki D, Miyahara K. [Usefulness of Respiratory Suppression for Abdominal Using EPI Sequences]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2020; 76:385-393. [PMID: 32307366 DOI: 10.6009/jjrt.2020_jsrt_76.4.385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The upper abdomen was imaged with diffusion weighted images for free breathing and respiratory suppression using single shot-echo planar imaging (SS-EPI) and readout segmented-EPI (RS-EPI). We examined the usefulness of respiratory suppression imaging for the subject of healthy volunteers. Motion artifacts, apparent diffusion coefficient (ADC) values, and organs movement distances were evaluated. As a result, motion artifacts and organs movement distances were reduced in respiratory suppression than free breathing. The ADC values did not change. Respiratory suppression was simple and useful. In addition, it was found that RS-EPI imaging could be used for imaging the upper abdomen in the same way as SS-EPI by respiratory suppression.
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Affiliation(s)
- Yuuki Yoshimura
- Department of Radiology Diagnosis, Okayama Saiseikai General Hospital
- Graduate School of Health Sciences, Okayama University
| | - Daisuke Suzuki
- Department of Radiology Diagnosis, Okayama Saiseikai General Hospital
| | - Kanae Miyahara
- Department of Radiology Diagnosis, Okayama Saiseikai General Hospital
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17
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Sæverud HA, Falk RS, Dowrick A, Eriksen M, Aarrestad S, Skjønsberg OH. Measuring diaphragm movement and respiratory frequency using a novel ultrasound device in healthy volunteers. J Ultrasound 2019; 24:15-22. [PMID: 31691921 DOI: 10.1007/s40477-019-00412-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 10/25/2019] [Indexed: 11/26/2022] Open
Abstract
PURPOSE To evaluate the ability of a novel ultrasound (US) device, DiaMon, to monitor diaphragm movement via its proxy liver movement, and compare it with the respired flow measured with a flowmeter, in awake and healthy volunteers. We wanted to (1) establish the optimal anatomical position for attaching the DiaMon device to the abdominal wall, and (2) evaluate the accuracy of continuous monitoring of respiratory frequency. METHODS Thirty healthy subjects were recruited. The DiaMon probe was applied subcostally in four different positions with the subjects in five different postures. The subjects breathed tidal volumes into a spirometer for 30-60 s with the DiaMon recording simultaneously. RESULTS The device detected a readable signal in 83-100% of the position/posture-combinations. The technical correlation between the two signals was highest in the anterior axillary-supine position (mean ± SD: 0.95 ± 0.03), followed by paramidline-supine (0.90 ± 0.09) and midclavicular-supine (0.89 ± 0.12). The frequency measurements yielded a mean difference of 0.03 (95% limits of agreement - 0.11, 0.16) breaths per minute in the anterior axillary-supine position. CONCLUSION The DiaMon device is able to detect liver movement in most subjects, and it measures breathing frequency accurately.
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Affiliation(s)
| | - Ragnhild Sørum Falk
- Oslo Centre for Biostatistics and Epidemiology, Research Support Services, Oslo University Hospital, Oslo, Norway
| | | | | | - Sigurd Aarrestad
- Department of Pulmonary Medicine, Oslo University Hospital, Kirkeveien 166, 0450, Oslo, Norway
- Norwegian National Advisory Unit on Long Term Mechanical Ventilation, Haukeland University Hospital, Bergen, Norway
| | - Ole Henning Skjønsberg
- Department of Pulmonary Medicine, Oslo University Hospital, Kirkeveien 166, 0450, Oslo, Norway
- Faculty of Medicine, University of Oslo, Oslo, Norway
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18
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Investigating the impact of tumour motion on TomoTherapy stereotactic ablative body radiotherapy (SABR) deliveries on 3-dimensional and 4-dimensional computed tomography. AUSTRALASIAN PHYSICAL & ENGINEERING SCIENCES IN MEDICINE 2019; 42:169-179. [PMID: 30790140 DOI: 10.1007/s13246-019-00727-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 01/18/2019] [Indexed: 12/25/2022]
Abstract
TomoTherapy can provide highly accurate SABR deliveries, but currently it does not have any effective motion management techniques. Shallow breathing has been identified as one possible motion management solution on TomoTherapy, which has been made possible with the BreatheWell audiovisual biofeedback (AVB) device. Since both the shallow breathing technique and the clinical use of the BreatheWell device are novel, their implementation requires comprehensive verification and validation work. As the first stage of the validation, this paper investigates the impact of target motion on a TomoTherapy SABR delivery is assessed on both 3D CT and 4D CT using a 4D respiratory phantom. A dosimetric study on a 4D respiratory phantom was conducted, with the phantom's insert designed to move at four different amplitudes in the superior-inferior direction. SABR plans on 3D and 4D CT scans were created and measured. Critical plan statistics and measurement results were compared. It is found that for TomoTherapy SABR deliveries, by reducing the targets respiratory motion, target coverage, organ-at-risk (OAR) sparing, and delivery accuracy were improved.
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19
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Mostafaei F, Tai A, Omari E, Song Y, Christian J, Paulson E, Hall W, Erickson B, Li XA. Variations of MRI-assessed peristaltic motions during radiation therapy. PLoS One 2018; 13:e0205917. [PMID: 30359413 PMCID: PMC6201905 DOI: 10.1371/journal.pone.0205917] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 10/03/2018] [Indexed: 11/19/2022] Open
Abstract
PURPOSE Understanding complex abdominal organ motion is essential for motion management in radiation therapy (RT) of abdominal tumors. This study investigates abdominal motion induced by respiration and peristalsis, during various time durations relevant to RT, using various CT and MRI techniques acquired under free breathing (FB) and breath hold (BH). METHODS A series of CT and MRI images acquired with various techniques under free breathing and/or breath hold from 37 randomly-selected pancreatic or liver cancer patients were analyzed to assess the motion in various time frames. These data include FB 4DCT from 15 patients (for motion in time duration of 5 sec), FB 2D cine-MRI from 4 patients (time duration of 1.7 min, 1 second acquisition time per slice), FB cine-MRI acquired using MR-Linac from 6 patients in various fractions (acquisition time is less than 0.6 seconds per slice), FB 4DMRI from 2 patients (time duration of 2 min), respiration-gated T2 with gating at the end expiration (time duration of 3-5 min), and BH T1 with multiphase dynamic contrast in acquisition times of 17 seconds for each of five phases (pre-contrast, arterial, venous, portal venous and delayed post-contrast) from 10 patients. Motions of various organs including gallbladder (GB) and liver were measured based on these MRI data. The GB motion includes both respiration and peristalsis, while liver motion is primarily respiration. By subtracting liver motion (respiration) from GB motion (respiration and peristalsis), the peristaltic motion, along with small residual motion, was obtained. RESULTS From cine-MRI, the residual motion beyond the respiratory motion was found to be up to 0.6 cm in superior-inferior (SI) and 0.55 cm in anterior-posterior (AP) directions. From 2D cine-MRI acquired by the MR-Linac, different peristaltic motions were found from different fractions for each patient. The peristaltic motion was found to vary between 0.3-1 cm. From BH T1 phase images, the average motions that were primarily due to peristalsis movements were found to be 1.2 cm in SI, 0.7 cm in AP, and 0.9 cm in left-right (LR) directions. The average motions assessed from 4DCT were 1.0 cm in SI and 0.3 cm in AP directions, which were generally smaller than the motions assessed from cine-MRI, i.e., 1.8 cm in SI and 0.6 cm in AP directions, for the same patients. However, average motions from 4DMRI, which are coming from respiratory were measured to be 1.5, 0.5, and 0.4 cm in SI, AP, and LR directions, respectively. CONCLUSION The abdominal motion due to peristalsis can be similar in magnitude to respiratory motion as assessed. These motions can be irregular and persistent throughout the imaging and RT delivery procedures, and should be considered together with respiratory motion during RT for abdominal tumors.
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Affiliation(s)
- Farshad Mostafaei
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - An Tai
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Eenas Omari
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Yingqiu Song
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Union Hospital Cancer Center, Huazhong University of Science and Technology, Wuhan, China
| | - James Christian
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Eric Paulson
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - William Hall
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Beth Erickson
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - X. Allen Li
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- * E-mail:
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Abstract
The unique ability of magnetic resonance imaging to measure temperature noninvasively, in vivo, makes it an attractive tool for monitoring interventional procedures, such as radiofrequency or microwave ablation in real-time. The most frequently used approach for magnetic resonance-based temperature measurement is proton resonance frequency (PRF) thermometry. Although it has many advantages, including tissue-independence and real-time capability, the main drawback is its motion sensitivity. This is likely the reason PRF thermometry in moving organs, such as the liver, is not commonly used in the clinical arena. In recent years, however, several developments suggest that motion-corrected thermometry in the liver is achievable. The present article summarizes the diverse attempts to correct thermometry in the liver. Therefore, the physical principle of PRF is introduced, with additional references for necrosis zone estimation and how to deal with fat phase modulation, and main magnetic field drifts. The primary categories of motion correction are presented, including general methods for motion compensation and library-based approaches, and referenceless thermometry and hybrid methods. Practical validation of the described methods in larger patient groups will be necessary to establish accurate motion-corrected thermometry in the clinical arena, with the goal of complete liver tumor ablation.
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Automatic planning of needle placement for robot-assisted percutaneous procedures. Int J Comput Assist Radiol Surg 2018; 13:1429-1438. [PMID: 29671199 DOI: 10.1007/s11548-018-1754-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Accepted: 03/26/2018] [Indexed: 12/24/2022]
Abstract
PURPOSE Percutaneous procedures allow interventional radiologists to perform diagnoses or treatments guided by an imaging device, typically a computed tomography (CT) scanner with a high spatial resolution. To reduce exposure to radiations and improve accuracy, robotic assistance to needle insertion is considered in the case of X-ray guided procedures. We introduce a planning algorithm that computes a needle placement compatible with both the patient's anatomy and the accessibility of the robot within the scanner gantry. METHODS Our preoperative planning approach is based on inverse kinematics, fast collision detection, and bidirectional rapidly exploring random trees coupled with an efficient strategy of node addition. The algorithm computes the allowed needle entry zones over the patient's skin (accessibility map) from 3D models of the patient's anatomy, the environment (CT, bed), and the robot. The result includes the admissible robot joint path to target the prescribed internal point, through the entry point. A retrospective study was performed on 16 patients datasets in different conditions: without robot (WR) and with the robot on the left or the right side of the bed (RL/RR). RESULTS We provide an accessibility map ensuring a collision-free path of the robot and allowing for a needle placement compatible with the patient's anatomy. The result is obtained in an average time of about 1 min, even in difficult cases. The accessibility maps of RL and RR covered about a half of the surface of WR map in average, which offers a variety of options to insert the needle with the robot. We also measured the average distance between the needle and major obstacles such as the vessels and found that RL and RR produced needle placements almost as safe as WR. CONCLUSION The introduced planning method helped us prove that it is possible to use such a "general purpose" redundant manipulator equipped with a dedicated tool to perform percutaneous interventions in cluttered spaces like a CT gantry.
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Park S, Farah R, Shea SM, Tryggestad E, Hales R, Lee J. Simultaneous tumor and surrogate motion tracking with dynamic MRI for radiation therapy planning. Phys Med Biol 2018; 63:025015. [PMID: 29243669 DOI: 10.1088/1361-6560/aaa20b] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Respiration-induced tumor motion is a major obstacle for achieving high-precision radiotherapy of cancers in the thoracic and abdominal regions. Surrogate-based estimation and tracking methods are commonly used in radiotherapy, but with limited understanding of quantified correlation to tumor motion. In this study, we propose a method to simultaneously track the lung tumor and external surrogates to evaluate their spatial correlation in a quantitative way using dynamic MRI, which allows real-time acquisition without ionizing radiation exposure. To capture the lung and whole tumor, four MRI-compatible fiducials are placed on the patient's chest and upper abdomen. Two different types of acquisitions are performed in the sagittal orientation including multi-slice 2D cine MRIs to reconstruct 4D-MRI and two-slice 2D cine MRIs to simultaneously track the tumor and fiducials. A phase-binned 4D-MRI is first reconstructed from multi-slice MR images using body area as a respiratory surrogate and groupwise registration. The 4D-MRI provides 3D template volumes for different breathing phases. 3D tumor position is calculated by 3D-2D template matching in which 3D tumor templates in the 4D-MRI reconstruction and the 2D cine MRIs from the two-slice tracking dataset are registered. 3D trajectories of the external surrogates are derived via matching a 3D geometrical model of the fiducials to their segmentations on the 2D cine MRIs. We tested our method on ten lung cancer patients. Using a correlation analysis, the 3D tumor trajectory demonstrates a noticeable phase mismatch and significant cycle-to-cycle motion variation, while the external surrogate was not sensitive enough to capture such variations. Additionally, there was significant phase mismatch between surrogate signals obtained from the fiducials at different locations.
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Affiliation(s)
- Seyoun Park
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, MD, United States of America
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Lee SY, Lim S, Ma SY, Yu J. Gross tumor volume dependency on phase sorting methods of four-dimensional computed tomography images for lung cancer. Radiat Oncol J 2017; 35:274-280. [PMID: 29037025 PMCID: PMC5647759 DOI: 10.3857/roj.2017.00444] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 09/18/2017] [Accepted: 09/28/2017] [Indexed: 12/25/2022] Open
Abstract
Purpose To see the gross tumor volume (GTV) dependency according to the phase selection and reconstruction methods, we measured and analyzed the changes of tumor volume and motion at each phase in 20 cases with lung cancer patients who underwent image-guided radiotherapy. Materials and Methods We retrospectively analyzed four-dimensional computed tomography (4D-CT) images in 20 cases of 19 patients who underwent image-guided radiotherapy. The 4D-CT images were reconstructed by the maximum intensity projection (MIP) and the minimum intensity projection (Min-IP) method after sorting phase as 40%–60%, 30%–70%, and 0%–90%. We analyzed the relationship between the range of motion and the change of GTV according to the reconstruction method. Results The motion ranges of GTVs are statistically significant only for the tumor motion in craniocaudal direction. The discrepancies of GTV volume and motion between MIP and Min-IP increased rapidly as the wider ranges of duty cycles are selected. Conclusion As narrow as possible duty cycle such as 40%–60% and MIP reconstruction was suitable for lung cancer if the respiration was stable. Selecting the reconstruction methods and duty cycle is important for small size and for large motion range tumors.
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Affiliation(s)
- Soo Yong Lee
- Department of Radiation Oncology, Kosin University Gospel Hospital, Kosin University College of Medicine, Busan, Korea
| | - Sangwook Lim
- Department of Radiation Oncology, Kosin University Gospel Hospital, Kosin University College of Medicine, Busan, Korea
| | - Sun Young Ma
- Department of Radiation Oncology, Kosin University Gospel Hospital, Kosin University College of Medicine, Busan, Korea
| | - Jesang Yu
- Department of Radiation Oncology, Kosin University Gospel Hospital, Kosin University College of Medicine, Busan, Korea
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Küstner T, Schwartz M, Martirosian P, Gatidis S, Seith F, Gilliam C, Blu T, Fayad H, Visvikis D, Schick F, Yang B, Schmidt H, Schwenzer NF. MR-based respiratory and cardiac motion correction for PET imaging. Med Image Anal 2017; 42:129-144. [PMID: 28800546 DOI: 10.1016/j.media.2017.08.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 07/18/2017] [Accepted: 08/01/2017] [Indexed: 01/22/2023]
Abstract
PURPOSE To develop a motion correction for Positron-Emission-Tomography (PET) using simultaneously acquired magnetic-resonance (MR) images within 90 s. METHODS A 90 s MR acquisition allows the generation of a cardiac and respiratory motion model of the body trunk. Thereafter, further diagnostic MR sequences can be recorded during the PET examination without any limitation. To provide full PET scan time coverage, a sensor fusion approach maps external motion signals (respiratory belt, ECG-derived respiration signal) to a complete surrogate signal on which the retrospective data binning is performed. A joint Compressed Sensing reconstruction and motion estimation of the subsampled data provides motion-resolved MR images (respiratory + cardiac). A 1-POINT DIXON method is applied to these MR images to derive a motion-resolved attenuation map. The motion model and the attenuation map are fed to the Customizable and Advanced Software for Tomographic Reconstruction (CASToR) PET reconstruction system in which the motion correction is incorporated. All reconstruction steps are performed online on the scanner via Gadgetron to provide a clinically feasible setup for improved general applicability. The method was evaluated on 36 patients with suspected liver or lung metastasis in terms of lesion quantification (SUVmax, SNR, contrast), delineation (FWHM, slope steepness) and diagnostic confidence level (3-point Likert-scale). RESULTS A motion correction could be conducted for all patients, however, only in 30 patients moving lesions could be observed. For the examined 134 malignant lesions, an average improvement in lesion quantification of 22%, delineation of 64% and diagnostic confidence level of 23% was achieved. CONCLUSION The proposed method provides a clinically feasible setup for respiratory and cardiac motion correction of PET data by simultaneous short-term MRI. The acquisition sequence and all reconstruction steps are publicly available to foster multi-center studies and various motion correction scenarios.
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Affiliation(s)
- Thomas Küstner
- Institute of Signal Processing and System Theory, University of Stuttgart, Stuttgart, Germany; Department of Radiology, University of Tübingen, Tübingen, Germany.
| | - Martin Schwartz
- Institute of Signal Processing and System Theory, University of Stuttgart, Stuttgart, Germany; Section on Experimental Radiology, University of Tübingen, Germany
| | | | - Sergios Gatidis
- Department of Radiology, University of Tübingen, Tübingen, Germany
| | - Ferdinand Seith
- Department of Radiology, University of Tübingen, Tübingen, Germany
| | - Christopher Gilliam
- Department of Electronic Engineering, Chinese University of Hong Kong, Hong Kong
| | - Thierry Blu
- Department of Electronic Engineering, Chinese University of Hong Kong, Hong Kong
| | - Hadi Fayad
- INSERM U1101, LaTIM, University of Bretagne, Brest, France
| | | | - F Schick
- Section on Experimental Radiology, University of Tübingen, Germany
| | - B Yang
- Institute of Signal Processing and System Theory, University of Stuttgart, Stuttgart, Germany
| | - H Schmidt
- Department of Radiology, University of Tübingen, Tübingen, Germany
| | - N F Schwenzer
- Department of Radiology, University of Tübingen, Tübingen, Germany
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Zhou P, Zhang Z, Hong Y, Cai H, Zhao H, Xu P, Zhao Y, Lin S, Qin X, Guo J, Pan Y, Dai J. The predictive value of serial changes in diaphragm function during the spontaneous breathing trial for weaning outcome: a study protocol. BMJ Open 2017; 7:e015043. [PMID: 28645964 PMCID: PMC5623446 DOI: 10.1136/bmjopen-2016-015043] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
INTRODUCTION There is a variety of tools being used in clinical practice for the prediction of weaning success from mechanical ventilation. However, their diagnostic performances are less than satisfactory. The purpose of this study is to investigate the value of serial changes in diaphragm function measured by ultrasound during the spontaneous breathing trial (SBT) as a weaning predictor. METHODS AND ANALYSIS This is a prospective observational study conducted in a 10-bed medical emergency intensive care unit (EICU) in a university-affiliated hospital. The study will be performed from November 2016 to December 2017. All patients in the EICU who are expected to have mechanical ventilation for more than 48 hours through endotracheal tube are potentially eligible for this study. Patients will be included if they fulfil the criteria for SBT. All enrolled patients will be ventilated with an Evita-4 by using volume assist control mode prior to SBT. Positive end-expiratory pressure (PEEP) will be set to 5 cmH2O and fractional inspired oxygen (FiO2) will be set to a value below 0.5 that guarantees oxygen saturation by pulse oximetry (SpO2) greater than 90%. Enrolled patients will undergo SBT for 2 hours in semirecumbent position. During the SBT, the patients will breathe through the ventilator circuit by using flow triggering (2 L/min) with automatic tube compensation of 100% and 5 cmH2O PEEP. The FiO2 will be set to the same value as used before SBT. If the patients fail to tolerate the SBT, the trial will be discontinued immediately and the ventilation mode will be switched to that used before the trial. Patients who pass the 2-hour SBT will be extubated. Right diaphragm excursion and bilateral diaphragm thickening fraction will be measured by ultrasonography during spontaneous breathing. Images will be obtained immediately prior to the SBT, and at 5, 30, 60, 90 and 120 min after the initiation of SBT. Rapid shallow breathing index will be simultaneously calculated at the bedside by a respiratory nurse. ETHICS AND DISSEMINATION The study protocol is approved by the ethics committee of Sir Run Run Shaw Hospital, an affiliate of Zhejiang University, Medical College. The results will be published in a peer-reviewed journal and shared with the worldwide medical community. TRIAL REGISTRATION NUMBER ISRCTN42917473; Pre-results.
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Affiliation(s)
- Pengmin Zhou
- Department of Emergency Medicine, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Zhongheng Zhang
- Department of Emergency Medicine, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yucai Hong
- Department of Emergency Medicine, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Huabo Cai
- Department of Emergency Medicine, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Hui Zhao
- Department of Emergency Medicine, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Peifeng Xu
- Department of Respiratory Therapy Medicine, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yiming Zhao
- Department of Emergency Medicine, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Shengping Lin
- Department of Emergency Medicine, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Xuchang Qin
- Department of Emergency Medicine, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - JiaWei Guo
- Department of Emergency Medicine, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yun Pan
- Department of Emergency Medicine, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Junru Dai
- Department of Emergency Medicine, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
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Brandner ED, Chetty IJ, Giaddui TG, Xiao Y, Huq MS. Motion management strategies and technical issues associated with stereotactic body radiotherapy of thoracic and upper abdominal tumors: A review from NRG oncology. Med Phys 2017; 44:2595-2612. [PMID: 28317123 DOI: 10.1002/mp.12227] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 01/23/2017] [Accepted: 03/10/2017] [Indexed: 12/11/2022] Open
Abstract
The efficacy of stereotactic body radiotherapy (SBRT) has been well demonstrated. However, it presents unique challenges for accurate planning and delivery especially in the lungs and upper abdomen where respiratory motion can be significantly confounding accurate targeting and avoidance of normal tissues. In this paper, we review the current literature on SBRT for lung and upper abdominal tumors with particular emphasis on addressing respiratory motion and its affects. We provide recommendations on strategies to manage motion for different, patient-specific situations. Some of the recommendations will potentially be adopted to guide clinical trial protocols.
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Affiliation(s)
- Edward D Brandner
- Department of Radiation Oncology, University of Pittsburgh Cancer Institute and UPMC CancerCenter, Pittsburgh, PA, 15232, USA
| | - Indrin J Chetty
- Department of Radiation Oncology, Henry Ford Health System, Detroit, MI, 48202, USA
| | - Tawfik G Giaddui
- Sidney Kimmel Cancer Center, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Ying Xiao
- Imaging and Radiation Oncology Core (IROC), University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - M Saiful Huq
- Department of Radiation Oncology, University of Pittsburgh Cancer Institute and UPMC CancerCenter, Pittsburgh, PA, 15232, USA
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Lee CK, Seo N, Kim B, Huh J, Kim JK, Lee SS, Kim IS, Nickel D, Kim KW. The Effects of Breathing Motion on DCE-MRI Images: Phantom Studies Simulating Respiratory Motion to Compare CAIPIRINHA-VIBE, Radial-VIBE, and Conventional VIBE. Korean J Radiol 2017; 18:289-298. [PMID: 28246509 PMCID: PMC5313517 DOI: 10.3348/kjr.2017.18.2.289] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 10/18/2016] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To compare the breathing effects on dynamic contrast-enhanced (DCE)-MRI between controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA)-volumetric interpolated breath-hold examination (VIBE), radial VIBE with k-space-weighted image contrast view-sharing (radial-VIBE), and conventional VIBE (c-VIBE) sequences using a dedicated phantom experiment. MATERIALS AND METHODS We developed a moving platform to simulate breathing motion. We conducted dynamic scanning on a 3T machine (MAGNETOM Skyra, Siemens Healthcare) using CAIPIRINHA-VIBE, radial-VIBE, and c-VIBE for six minutes per sequence. We acquired MRI images of the phantom in both static and moving modes, and we also obtained motion-corrected images for the motion mode. We compared the signal stability and signal-to-noise ratio (SNR) of each sequence according to motion state and used the coefficients of variation (CoV) to determine the degree of signal stability. RESULTS With motion, CAIPIRINHA-VIBE showed the best image quality, and the motion correction aligned the images very well. The CoV (%) of CAIPIRINHA-VIBE in the moving mode (18.65) decreased significantly after the motion correction (2.56) (p < 0.001). In contrast, c-VIBE showed severe breathing motion artifacts that did not improve after motion correction. For radial-VIBE, the position of the phantom in the images did not change during motion, but streak artifacts significantly degraded image quality, also after motion correction. In addition, SNR increased in both CAIPIRINHA-VIBE (from 3.37 to 9.41, p < 0.001) and radial-VIBE (from 4.3 to 4.96, p < 0.001) after motion correction. CONCLUSION CAIPIRINHA-VIBE performed best for free-breathing DCE-MRI after motion correction, with excellent image quality.
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Affiliation(s)
- Chang Kyung Lee
- Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Nieun Seo
- Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea.; Department of Radiology, Yonsei University College of Medicine, Severance Hospital, Seoul 03722, Korea
| | - Bohyun Kim
- Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea.; Department of Radiology, Ajou Unversity School of Medicine, Suwon 16499, Korea
| | - Jimi Huh
- Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea.; Department of Radiology, Ulsan University Hospital, Ulsan 44033, Korea
| | - Jeong Kon Kim
- Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Seung Soo Lee
- Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
| | | | - Dominik Nickel
- MR Application Predevelopment, Siemens Healthcare, Erlangen 91052, Germany
| | - Kyung Won Kim
- Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
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Glitzner M, Fast MF, de Senneville BD, Nill S, Oelfke U, Lagendijk JJW, Raaymakers BW, Crijns SPM. Real-time auto-adaptive margin generation for MLC-tracked radiotherapy. Phys Med Biol 2017; 62:186-201. [PMID: 27991457 PMCID: PMC5952335 DOI: 10.1088/1361-6560/62/1/186] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 10/16/2016] [Accepted: 11/09/2016] [Indexed: 11/12/2022]
Abstract
In radiotherapy, abdominal and thoracic sites are candidates for performing motion tracking. With real-time control it is possible to adjust the multileaf collimator (MLC) position to the target position. However, positions are not perfectly matched and position errors arise from system delays and complicated response of the electromechanic MLC system. Although, it is possible to compensate parts of these errors by using predictors, residual errors remain and need to be compensated to retain target coverage. This work presents a method to statistically describe tracking errors and to automatically derive a patient-specific, per-segment margin to compensate the arising underdosage on-line, i.e. during plan delivery. The statistics of the geometric error between intended and actual machine position are derived using kernel density estimators. Subsequently a margin is calculated on-line according to a selected coverage parameter, which determines the amount of accepted underdosage. The margin is then applied onto the actual segment to accommodate the positioning errors in the enlarged segment. The proof-of-concept was tested in an on-line tracking experiment and showed the ability to recover underdosages for two test cases, increasing [Formula: see text] in the underdosed area about [Formula: see text] and [Formula: see text], respectively. The used dose model was able to predict the loss of dose due to tracking errors and could be used to infer the necessary margins. The implementation had a running time of 23 ms which is compatible with real-time requirements of MLC tracking systems. The auto-adaptivity to machine and patient characteristics makes the technique a generic yet intuitive candidate to avoid underdosages due to MLC tracking errors.
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Affiliation(s)
- M Glitzner
- Department of Radiotherapy, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - M F Fast
- Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, UK
| | - B Denis de Senneville
- Department of Radiotherapy, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
- Mathematical Institute of Bordeaux, UMR 5251 CNRS/University of Bordeaux, 33405 Talence Cedex, France
| | - S Nill
- Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, UK
| | - U Oelfke
- Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, UK
| | - J J W Lagendijk
- Department of Radiotherapy, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - B W Raaymakers
- Department of Radiotherapy, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - S P M Crijns
- Department of Radiotherapy, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
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Cavaiola C, Saccomandi P, Massaroni C, Tosi D, Giurazza F, Frauenfelder G, Beomonte Zobel B, Di Matteo FM, Caponero MA, Polimadei A, Schena E. Error of a Temperature Probe for Cancer Ablation Monitoring Caused by Respiratory Movements: <italic>Ex Vivo</italic> and <italic>In Vivo</italic> Analysis. IEEE SENSORS JOURNAL 2016; 16:5934-5941. [DOI: 10.1109/jsen.2016.2574959] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
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Sferrazza Papa GF, Pellegrino GM, Di Marco F, Imeri G, Brochard L, Goligher E, Centanni S. A Review of the Ultrasound Assessment of Diaphragmatic Function in Clinical Practice. Respiration 2016; 91:403-11. [DOI: 10.1159/000446518] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Accepted: 04/29/2016] [Indexed: 11/19/2022] Open
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Hocquelet A, Trillaud H, Frulio N, Papadopoulos P, Balageas P, Salut C, Meyer M, Blanc JF, Montaudon M, Denis de Senneville B. Three-Dimensional Measurement of Hepatocellular Carcinoma Ablation Zones and Margins for Predicting Local Tumor Progression. J Vasc Interv Radiol 2016; 27:1038-1045.e2. [PMID: 27156743 DOI: 10.1016/j.jvir.2016.02.031] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 02/25/2016] [Accepted: 02/25/2016] [Indexed: 02/07/2023] Open
Abstract
PURPOSE To propose a postprocessing technique that measures tumor surface with insufficient ablative margins (≤ 5 mm) on magnetic resonance (MR) imaging to predict local tumor progression (LTP) following radiofrequency (RF) ablation. MATERIALS AND METHODS A diagnostic method is proposed based on measurement of tumor surface with a margin ≤ 5 mm on MR imaging. The postprocessing technique includes fully automatic registration of pre- and post-RF ablation MR imaging, a semiautomatic segmentation of pre-RF ablation tumor and post-RF ablation volume, and a subsequent calculation of the three-dimensional exposed tumor surface area. The ability to use this surface margin ≤ 5 mm to predict local recurrence at 2 years was then tested on 16 patients with cirrhosis who were treated by RF ablation with a margin ≤ 5 mm in 2012: eight with LTP matched according to tumor size and number and α-fetoprotein level versus eight without local recurrence. RESULTS The error of estimated tumor surface with a margin ≤ 5 mm was less than 12%. Results of a log-rank test showed that patients with a tumor surface area > 425 mm(2) had a 2-year LTP rate of 77.5%, compared with 25% for patients with a tumor surface area ≤ 425 mm(2) (P = .018). CONCLUSIONS This proof-of-concept study proposes an accurate and reliable postprocessing technique to estimate tumor surface with insufficient ablative margins, and underscores the potential usefulness of tumor surface with a margin ≤ 5 mm to stratify patients with HCC treated by RF ablation according to their risk of LTP.
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Affiliation(s)
- Arnaud Hocquelet
- Department of Diagnostic and Interventional Imaging, Hôpital Saint-André, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France.
| | - Hervé Trillaud
- Department of Diagnostic and Interventional Imaging, Hôpital Saint-André, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France
| | - Nora Frulio
- Department of Diagnostic and Interventional Imaging, Hôpital Saint-André, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France
| | - Panteleimon Papadopoulos
- Department of Diagnostic and Interventional Imaging, Hôpital Saint-André, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France
| | - Pierre Balageas
- Department of Diagnostic and Interventional Imaging, Hôpital Saint-André, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France
| | - Cécile Salut
- Department of Diagnostic and Interventional Imaging, Hôpital Saint-André, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France
| | - Marie Meyer
- Department of Diagnostic and Interventional Imaging, Hôpital Saint-André, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France
| | - Jean-Frédéric Blanc
- Department of HepatoGastroenterology and Digestive Oncology, Hôpital Saint-André, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France
| | - Michel Montaudon
- Department of Diagnostic and Interventional Imaging, Hôpital Haut-Lévêque, Centre Hospitalier Universitaire de Bordeaux, Pessac, France
| | - Baudouin Denis de Senneville
- Institut de Mathématiques de Bordeaux, Unité Mixte de Recherche 5251, Centre National de Recherche Scientifique/Universitaire de Bordeaux, Talence, France
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Cruz G, Atkinson D, Buerger C, Schaeffter T, Prieto C. Accelerated motion corrected three-dimensional abdominal MRI using total variation regularized SENSE reconstruction. Magn Reson Med 2016; 75:1484-98. [PMID: 25996443 PMCID: PMC4979665 DOI: 10.1002/mrm.25708] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 02/16/2015] [Accepted: 03/10/2015] [Indexed: 01/20/2023]
Abstract
PURPOSE Develop a nonrigid motion corrected reconstruction for highly accelerated free-breathing three-dimensional (3D) abdominal images without external sensors or additional scans. METHODS The proposed method accelerates the acquisition by undersampling and performs motion correction directly in the reconstruction using a general matrix description of the acquisition. Data are acquired using a self-gated 3D golden radial phase encoding trajectory, enabling a two stage reconstruction to estimate and then correct motion of the same data. In the first stage total variation regularized iterative SENSE is used to reconstruct highly undersampled respiratory resolved images. A nonrigid registration of these images is performed to estimate the complex motion in the abdomen. In the second stage, the estimated motion fields are incorporated in a general matrix reconstruction, which uses total variation regularization and incorporates k-space data from multiple respiratory positions. The proposed approach was tested on nine healthy volunteers and compared against a standard gated reconstruction using measures of liver sharpness, gradient entropy, visual assessment of image sharpness and overall image quality by two experts. RESULTS The proposed method achieves similar quality to the gated reconstruction with nonsignificant differences for liver sharpness (1.18 and 1.00, respectively), gradient entropy (1.00 and 1.00), visual score of image sharpness (2.22 and 2.44), and visual rank of image quality (3.33 and 3.39). An average reduction of the acquisition time from 102 s to 39 s could be achieved with the proposed method. CONCLUSION In vivo results demonstrate the feasibility of the proposed method showing similar image quality to the standard gated reconstruction while using data corresponding to a significantly reduced acquisition time. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance.
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Affiliation(s)
- Gastao Cruz
- King's College LondonDivision of Imaging Sciences and Biomedical EngineeringLondonUnited Kingdom
| | - David Atkinson
- Centre for Medical ImagingUniversity College LondonLondonUnited Kingdom
| | | | - Tobias Schaeffter
- King's College LondonDivision of Imaging Sciences and Biomedical EngineeringLondonUnited Kingdom
| | - Claudia Prieto
- King's College LondonDivision of Imaging Sciences and Biomedical EngineeringLondonUnited Kingdom
- Pontificia Universidad Católica de Chile, Escuela de IngenieríaSantiagoChile
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Abstract
Subject motion is unavoidable in clinical and research imaging studies. Breathing is the most important source of motion in whole-body PET and MRI studies, affecting not only thoracic organs but also those in the upper and even lower abdomen. The motion related to the pumping action of the heart is obviously relevant in high-resolution cardiac studies. These two sources of motion are periodic and predictable, at least to a first approximation, which means certain techniques can be used to control the motion (eg, by acquiring the data when the organ of interest is relatively at rest). Additionally, nonperiodic and unpredictable motion can also occur during the scan. One obvious limitation of methods relying on external devices (eg, respiratory bellows or the electrocardiogram signal to monitor the respiratory or cardiac cycle, respectively) to trigger or gate the data acquisition is that the complex motion of internal organs cannot be fully characterized. However, detailed information can be obtained using either the PET or MRI data (or both) allowing the more complete characterization of the motion field so that a motion model can be built. Such a model and the information derived from simple external devices can be used to minimize the effects of motion on the collected data. In the ideal case, all the events recorded during the PET scan would be used to generate a motion-free or corrected PET image. The detailed motion field can be used for this purpose by applying it to the PET data before, during, or after the image reconstruction. Integrating all these methods for motion control, characterization, and correction into a workflow that can be used for routine clinical studies is challenging but could potentially be extremely valuable given the improvement in image quality and reduction of motion-related image artifacts.
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Affiliation(s)
- Ciprian Catana
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA.
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Haji K, Royse A, Green C, Botha J, Canty D, Royse C. Interpreting diaphragmatic movement with bedside imaging, review article. J Crit Care 2016; 34:56-65. [PMID: 27288611 DOI: 10.1016/j.jcrc.2016.03.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 02/09/2016] [Accepted: 03/04/2016] [Indexed: 12/11/2022]
Abstract
The diaphragm is the most important muscle of respiration. At equilibrium, the load imposed on the diaphragmatic muscles from transdiaphragmatic pressure balances the force generated by diaphragmatic muscles. However, procedural and nonprocedural thoracic and abdominal conditions may disrupt this equilibrium and impair diaphragmatic function. Diaphragmatic dysfunction is associated with respiratory insufficiency and poor outcome. Therefore, rapid diagnosis and early intervention may be useful. Ultrasound imaging provides quick and accurate bedside assessment of the diaphragm. Various imaging techniques have been suggested, using 2-dimensional and M-mode technology. Diaphragm viewing depends on the degree of robe movement, determined by the angle of incidence of the ultrasound beam and by the direction of probe movement. In this review, we will discuss the function of the diaphragm focusing on clinically important anatomical and physiological properties of the diaphragm. We will review the literature regarding various sonographic techniques for diaphragm assessment. We will also explore the evidence for the role of the tidal displacement of subdiaphragmatic organs as a surrogate for diaphragm movement.
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Affiliation(s)
- K Haji
- Department of Intensive Care Medicine, Frankston Hospital, Frankston, Faculty of Medicine, Nursing and Health Sciences, Monash University, Victoria, Australia.
| | - A Royse
- Department of Surgery, The University of Melbourne, The Royal Melbourne Hospital, Melbourne, Victoria, Australia
| | - C Green
- Department of Intensive Care Medicine, Frankston Hospital, Frankston, Faculty of Medicine, Nursing and Health Sciences, Monash University, Victoria, Australia
| | - J Botha
- Department of Intensive Care Medicine, Frankston Hospital, Frankston, Faculty of Medicine, Nursing and Health Sciences, Monash University, Victoria, Australia
| | - D Canty
- Department of Surgery, The University of Melbourne, Melbourne, Victoria, Australia
| | - C Royse
- Department of Anaesthesia and Pain Management, The Royal Melbourne Hospital, Melbourne, Victoria, Australia
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Hamzé N, Peterlík I, Cotin S, Essert C. Preoperative trajectory planning for percutaneous procedures in deformable environments. Comput Med Imaging Graph 2016; 47:16-28. [DOI: 10.1016/j.compmedimag.2015.10.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Revised: 10/01/2015] [Accepted: 10/18/2015] [Indexed: 12/19/2022]
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Holbrook AB, Ghanouni P, Santos JM, Dumoulin C, Medan Y, Pauly KB. Respiration based steering for high intensity focused ultrasound liver ablation. Magn Reson Med 2015; 71:797-806. [PMID: 23460510 DOI: 10.1002/mrm.24695] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
PURPOSE Respiratory motion makes hepatic ablation using high intensity focused ultrasound (HIFO) challenging. Previous HIFU liver treatment had required apnea induced during general anesthesia. We describe and test a system that allows treatment of the liver in the presence of breathing motion. METHODS Mapping a signal from an external respiratory bellow to treatment locations within the liver allows the ultrasound transducer to be steered in real time to the target location. Using a moving phantom, three metrics were used to compare static, steered, and unsteered sonications: the area of sonications once a temperature rise of 15°C was achieved, the energy deposition required to reach that temperature, and the average rate of temperature rise during the first 10 s of sonication. Steered HIFU in vivo ablations of the porcine liver were also performed and compared to breath-hold ablations. RESULTS For the last phantom metric, all groups were found to be statistically significantly different (P ≤ 0.003). However, in the other two metrics, the static and unsteered sonications were not statistically different (P > 0.9999). Steered in vivo HIFU ablations were not statistically significantly different from ablations during breath-holding. CONCLUSIONS A system for performing HIFU steering during ablation of the liver with breathing motion is presented and shown to achieve results equivalent to ablation performed with breath-holding.
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Affiliation(s)
- Andrew B Holbrook
- Department of Radiology, Stanford University, Stanford, California, USA
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Haji K, Royse A, Tharmaraj D, Haji D, Botha J, Royse C. Diaphragmatic regional displacement assessed by ultrasound and correlated to subphrenic organ movement in the critically ill patients—an observational study. J Crit Care 2015; 30:439.e7-13. [DOI: 10.1016/j.jcrc.2014.10.028] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2014] [Revised: 09/19/2014] [Accepted: 10/27/2014] [Indexed: 10/24/2022]
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Jani SS, Lamb JM, White BM, Dahlbom M, Robinson CG, Low DA. Assessing margin expansions of internal target volumes in 3D and 4D PET: a phantom study. Ann Nucl Med 2014; 29:100-9. [DOI: 10.1007/s12149-014-0914-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 10/02/2014] [Indexed: 12/13/2022]
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Abbas H, Chang B, Chen ZJ. Motion management in gastrointestinal cancers. J Gastrointest Oncol 2014; 5:223-35. [PMID: 24982771 DOI: 10.3978/j.issn.2078-6891.2014.028] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 05/27/2014] [Indexed: 12/17/2022] Open
Abstract
The presence of tumor and organ motions complicates the planning and delivery of radiotherapy for gastrointestinal cancers. Without proper accounting of the movements, target volume could be under-dosed and the nearby normal critical organs could be over-dosed. This situation is further exacerbated by the close proximity of abdominal tumors to many normal organs at risk (OARs). A number of strategies have been developed to deal with tumor and organ motions in radiotherapy. This article presents a review of the techniques used in the evaluation, quantification, and management of tumor and organ motions for radiotherapy of gastrointestinal cancers.
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Affiliation(s)
- Hassan Abbas
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Bryan Chang
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Zhe Jay Chen
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut, USA
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Lee D, Pollock S, Whelan B, Keall P, Kim T. Dynamic keyhole: A novel method to improve MR images in the presence of respiratory motion for real-time MRI. Med Phys 2014; 41:072304. [DOI: 10.1118/1.4883882] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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41
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Vijayan S, Reinertsen I, Hofstad EF, Rethy A, Hernes TAN, Langø T. Liver deformation in an animal model due to pneumoperitoneum assessed by a vessel-based deformable registration. MINIM INVASIV THER 2014; 23:279-86. [PMID: 24848136 DOI: 10.3109/13645706.2014.914955] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
PURPOSE Surgical navigation based on preoperative images partly overcomes some of the drawbacks of minimally invasive interventions - reduction of free sight, lack of dexterity and tactile feedback. The usefulness of preoperative images is limited in laparoscopic liver surgery, as the liver shifts due to respiration, induction of pneumoperitoneum and surgical manipulation. In this study, we evaluated the shift and deformation in an animal liver caused by respiration and pneumopertioneum using intraoperative cone beam CT. MATERIAL AND METHODS 3D cone beam CT scans were acquired with arterial contrast. The centerlines of the segmented vessels were extracted from the images taken at different respiration and pressure settings. A non-rigid registration method was used to measure the shift and deformation. The mean Euclidean distance between the annotated landmarks was used for evaluation. RESULTS A shift and deformation of 44.6 mm on average was introduced due to the combined effect of respiration and pneumoperitoneum. On average 91% of the deformations caused by the respiration and pneumoperitoneum were recovered. CONCLUSION The results can contribute to the use of intraoperative imaging to correct for anatomic shift so that preoperative data can be used with greater confidence and accuracy during guidance of laparoscopic liver procedures.
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Affiliation(s)
- Sinara Vijayan
- Department of Circulation and Medical Imaging, Norwegian University of Science and Technology (NTNU) , Trondheim , Norway
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Tsurusaki M, Okada M, Kuroda H, Matsuki M, Ishii K, Murakami T. Clinical application of 18F-fluorodeoxyglucose positron emission tomography for assessment and evaluation after therapy for malignant hepatic tumor. J Gastroenterol 2014; 49:46-56. [PMID: 23525980 PMCID: PMC3895191 DOI: 10.1007/s00535-013-0790-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Accepted: 03/04/2013] [Indexed: 02/04/2023]
Abstract
Positron emission tomography (PET) is widely available and its application with 2-[(18)F] fluoro-2-deoxy-D-glucose ((18)F-FDG) in oncology has become one of the standard imaging modalities in diagnosing and staging of tumors, and monitoring the therapeutic efficacy in hepatic malignancies. Recently, investigators have measured glucose utilization in liver tumors using (18)F-FDG and positron emission tomography/computer tomography (PET/CT) in order to establish a diagnosis of tumors, assess their biologic characteristics and predict therapeutic effects on hepatic malignancies. The PET/CT with (18)F-FDG may further enhance the hepatic malignancy diagnostic algorithm by accurate diagnosis, staging, restaging and evaluating its biological characteristics, which can benefit the patients suffering from primary and metastatic hepatic tumors such as hepatocellular carcinoma (HCC), cholangiocarcinoma (CCC), and metastatic liver tumor.
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Affiliation(s)
- Masakatsu Tsurusaki
- Department of Diagnostic Radiology, Kinki University, School of Medicine, 377-2 Ohnohigashi, Osaka-sayama, Osaka, 589-8511, Japan,
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Wysocka B, Moseley J, Brock K, Lockwood G, Wilson G, Simeonov A, Haider MA, Menard C, Bissonnette JP, Dawson LA, Ringash J. Assessment of nonrespiratory stomach motion in healthy volunteers in fasting and postprandial states. Pract Radiat Oncol 2013; 4:288-293. [PMID: 25194096 DOI: 10.1016/j.prro.2013.10.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 10/02/2013] [Accepted: 10/02/2013] [Indexed: 12/23/2022]
Abstract
PURPOSE To characterize nonrespiratory stomach motion in the fasting state and postprandial. METHODS AND MATERIALS Ten healthy volunteers underwent 2-dimensional Fiesta cine magnetic resonance imaging studies in 30-second voluntary breath hold, in axial, coronal, and 2 oblique planes while fasting, and 5, 15, 30, 45, and 60 minutes postmeal. Each stomach contour was delineated and sampled with 200 points. Matching points were found for all contours in the same 30-second acquisition. Using deformable parametric analysis (Matlab, version 7.1), mean magnitude, and standard deviation of displacement of each point were determined for each patient. Maximal, minimal, and median population values in 6 cardinal, and in any direction, were calculated. RESULTS The median of mean displacements for the baseline position of each point was small and rarely exceeded 1.1 mm; greatest value was 1.6 mm superior-inferior. Median displacement (pooled across time) in the right-left, superior-inferior, and anterior-posterior directions was 0.3 (range, -0.7 to 1.3), 0.8 (-0.4 to 2.4), and 0.3 (-1.1 to 1.6) mm, respectively. Fasting and postprandial standard deviation did not differ. CONCLUSIONS Nonrespiratory stomach displacement is small and stomach position is stable after a small, standard meal. Radiation therapy may be delivered at any time within the first hour after eating without significant compromise of planned planning target volumes.
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Affiliation(s)
- Barbara Wysocka
- Department of Radiation Oncology, Princess Margaret Cancer Centre, University of Toronto, Toronto, Ontario, Canada
| | - Joanne Moseley
- Department of Radiation Physics, Princess Margaret Cancer Centre, University of Toronto, Toronto, Ontario, Canada
| | - Kristy Brock
- Department of Radiation Physics, Princess Margaret Cancer Centre, University of Toronto, Toronto, Ontario, Canada
| | - Gina Lockwood
- Department of Biostatistics, University Health Network, Princess Margaret Cancer Centre, Toronto, Ontario, Canada
| | - Graham Wilson
- Department of Radiation Physics, Princess Margaret Cancer Centre, University of Toronto, Toronto, Ontario, Canada
| | - Anna Simeonov
- Department of Radiation Physics, Princess Margaret Cancer Centre, University of Toronto, Toronto, Ontario, Canada
| | - Masoom A Haider
- Department of Medical Imaging, Princess Margaret Cancer Centre, University of Toronto, Toronto, Ontario, Canada
| | - Cynthia Menard
- Department of Radiation Oncology, Princess Margaret Cancer Centre, University of Toronto, Toronto, Ontario, Canada
| | - Jean-Pierre Bissonnette
- Department of Radiation Physics, Princess Margaret Cancer Centre, University of Toronto, Toronto, Ontario, Canada
| | - Laura A Dawson
- Department of Radiation Oncology, Princess Margaret Cancer Centre, University of Toronto, Toronto, Ontario, Canada
| | - Jolie Ringash
- Department of Radiation Oncology, Princess Margaret Cancer Centre, University of Toronto, Toronto, Ontario, Canada.
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44
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Chan C, Jin X, Fung EK, Naganawa M, Mulnix T, Carson RE, Liu C. Event-by-event respiratory motion correction for PET with 3D internal-1D external motion correlation. Med Phys 2013; 40:112507. [DOI: 10.1118/1.4826165] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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45
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Bell CS, Obstein KL, Valdastri P. Image partitioning and illumination in image-based pose detection for teleoperated flexible endoscopes. Artif Intell Med 2013; 59:185-96. [PMID: 24188575 DOI: 10.1016/j.artmed.2013.09.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 09/20/2013] [Accepted: 09/23/2013] [Indexed: 02/07/2023]
Abstract
OBJECTIVE Colorectal cancer is one of the leading causes of cancer-related deaths in the world, although it can be effectively treated if detected early. Teleoperated flexible endoscopes are an emerging technology to ease patient apprehension about the procedure, and subsequently increase compliance. Essential to teleoperation is robust feedback reflecting the change in pose (i.e., position and orientation) of the tip of the endoscope. The goal of this study is to first describe a novel image-based tracking system for teleoperated flexible endoscopes, and subsequently determine its viability in a clinical setting. The proposed approach leverages artificial neural networks (ANNs) to learn the mapping that links the optical flow between two sequential images to the change in the pose of the camera. Secondly, the study investigates for the first time how narrow band illumination (NBI) - today available in commercial gastrointestinal endoscopes - can be applied to enhance feature extraction, and quantify the effect of NBI and white light illumination (WLI), as well as their color information, on the strength of features extracted from the endoscopic camera stream. METHODS AND MATERIALS In order to provide the best features for the neural networks to learn the change in pose based on the image stream, we investigated two different imaging modalities - WLI and NBI - and we applied two different spatial partitions - lumen-centered and grid-based - to create descriptors used as input to the ANNs. An experiment was performed to compare the error of these four variations, measured in root mean square error (RMSE) from ground truth given by a robotic arm, to that of a commercial state-of-the-art magnetic tracker. The viability of this technique for a clinical setting was then tested using the four ANN variations, a magnetic tracker, and a commercial colonoscope. The trial was performed by an expert endoscopist (>2000 lifetime procedures) on a colonoscopy training model with porcine blood, and the RMSE of the ANN output was calculated with respect to the magnetic tracker readings. Using the image stream obtained from the commercial endoscope, the strength of features extracted was evaluated. RESULTS In the first experiment, the best ANNs resulted from grid-based partitioning under WLI (2.42mm RMSE) for position, and from lumen-centered partitioning under NBI (1.69° RMSE) for rotation. By comparison, the performance of the tracker was 2.49mm RMSE in position and 0.89° RMSE in rotation. The trial with the commercial endoscope indicated that lumen-centered partitioning was the best overall, while NBI outperformed WLI in terms of illumination modality. The performance of lumen-centered partitioning with NBI was 1.03±0.8mm RMSE in positional degrees of freedom (DOF), and 1.26±0.98° RMSE in rotational DOF, while with WLI, the performance was 1.56±1.15mm RMSE in positional DOF and 2.45±1.90° RMSE in rotational DOF. Finally, the features extracted under NBI were found to be twice as strong as those extracted under WLI, but no significance in feature strengths was observed between a grayscale version of the image, and the red, blue, and green color channels. CONCLUSIONS This work demonstrates that both WLI and NBI, combined with feature partitioning based on the anatomy of the colon, provide valid mechanisms for endoscopic camera pose estimation via image stream. Illumination provided by WLI and NBI produce ANNs with similar performance which are comparable to that of a state-of-the-art magnetic tracker. However, NBI produces features that are stronger than WLI, which enables more robust feature tracking, and better performance of the ANN in terms of accuracy. Thus, NBI with lumen-centered partitioning resulted the best approach among the different variations tested for vision-based pose estimation. The proposed approach takes advantage of components already available in commercial gastrointestinal endoscopes to provide accurate feedback about the motion of the tip of the endoscope. This solution may serve as an enabling technology for closed-loop control of teleoperated flexible endoscopes.
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Affiliation(s)
- Charreau S Bell
- Department of Mechanical Engineering, Vanderbilt University, 2301 Vanderbilt Place, PMB 351826, Nashville, TN 37235-1826, USA.
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46
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Muller A, Petrusca L, Auboiroux V, Valette PJ, Salomir R, Cotton F. Management of Respiratory Motion in Extracorporeal High-Intensity Focused Ultrasound Treatment in Upper Abdominal Organs: Current Status and Perspectives. Cardiovasc Intervent Radiol 2013; 36:1464-1476. [DOI: 10.1007/s00270-013-0713-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Accepted: 05/08/2013] [Indexed: 12/25/2022]
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Aubry JF, Pauly KB, Moonen C, Haar GT, Ries M, Salomir R, Sokka S, Sekins KM, Shapira Y, Ye F, Huff-Simonin H, Eames M, Hananel A, Kassell N, Napoli A, Hwang JH, Wu F, Zhang L, Melzer A, Kim YS, Gedroyc WM. The road to clinical use of high-intensity focused ultrasound for liver cancer: technical and clinical consensus. J Ther Ultrasound 2013; 1:13. [PMID: 25512859 PMCID: PMC4265946 DOI: 10.1186/2050-5736-1-13] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 06/12/2013] [Indexed: 01/20/2023] Open
Abstract
Clinical use of high-intensity focused ultrasound (HIFU) under ultrasound or MR guidance as a non-invasive method for treating tumors is rapidly increasing. Tens of thousands of patients have been treated for uterine fibroid, benign prostate hyperplasia, bone metastases, or prostate cancer. Despite the methods' clinical potential, the liver is a particularly challenging organ for HIFU treatment due to the combined effect of respiratory-induced liver motion, partial blocking by the rib cage, and high perfusion/flow. Several technical and clinical solutions have been developed by various groups during the past 15 years to compensate for these problems. A review of current unmet clinical needs is given here, as well as a consensus from a panel of experts about technical and clinical requirements for upcoming pilot and pivotal studies in order to accelerate the development and adoption of focused ultrasound for the treatment of primary and secondary liver cancer.
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Affiliation(s)
- Jean-Francois Aubry
- Institut Langevin, ESPCI ParisTech, CNRS UMR 7587, INSERM U979, Université Denis Diderot, Paris VII, Paris, France
- Department of Radiation Oncology, University of Virginia, Charlottesville, VA, USA
| | - Kim Butts Pauly
- Radiological Sciences Laboratory, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Chrit Moonen
- Imaging Division, University Medical Center Utrecht, Amsterdam, The Netherlands
| | - Gail ter Haar
- Division of Radiotherapy and Imaging, The Institute of Cancer Research, Royal Marsden Hospital, Sutton, Surrey, UK
| | - Mario Ries
- Imaging Division, University Medical Center Utrecht, Amsterdam, The Netherlands
| | - Rares Salomir
- Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | | | | | | | - Fangwei Ye
- Chongqing Haifu Medical Technology Co., Ltd, Chongqing, China
| | | | - Matt Eames
- Focused Ultrasound Foundation, Charlottesville, VA, USA
| | - Arik Hananel
- Focused Ultrasound Foundation, Charlottesville, VA, USA
| | - Neal Kassell
- Focused Ultrasound Foundation, Charlottesville, VA, USA
| | | | - Joo Ha Hwang
- Digestive Disease Center, University of Washington, Seattle, WA, USA
| | - Feng Wu
- Institute of Ultrasonic Engineering in Medicine, Chongqing Medical University, Chongqing, China
| | - Lian Zhang
- Clinical Center for Tumor Therapy, Second Affiliated Hospital of Chongqing University of Medical Sciences, Chongqing, China
| | - Andreas Melzer
- Institute for Medical Science and Technology, University of Dundee, Dundee, Scotland, UK
| | - Young-sun Kim
- Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Wladyslaw M Gedroyc
- Department of Medicine, Imperial College, South Kensington Campus, Exhibition Rd, London SW7 2AZ, UK
- Saint Mary’s Hospital, Praed St, W2 1NY, London, UK
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48
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Grams ST, von Saltiél R, Mayer AF, Schivinski CIS, de S. Nobre LF, Nóbrega IS, Jacomino MEMLP, Paulin E. Assessment of the reproducibility of the indirect ultrasound method of measuring diaphragm mobility. Clin Physiol Funct Imaging 2013; 34:18-25. [DOI: 10.1111/cpf.12058] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Accepted: 05/10/2013] [Indexed: 11/30/2022]
Affiliation(s)
- Samantha T. Grams
- Health and Sports Science Centre; Santa Catarina State University (CEFID/UDESC); Florianópolis-SC Brazil
| | - Rossana von Saltiél
- Health and Sports Science Centre; Santa Catarina State University (CEFID/UDESC); Florianópolis-SC Brazil
| | - Anamaria F. Mayer
- Health and Sports Science Centre; Santa Catarina State University (CEFID/UDESC); Florianópolis-SC Brazil
| | - Camila I. S. Schivinski
- Health and Sports Science Centre; Santa Catarina State University (CEFID/UDESC); Florianópolis-SC Brazil
| | - Luiz Felipe de S. Nobre
- University Hospital of Federal University of Santa Catarina (HU/UFSC); Florianópolis-SC Brazil
| | - Isadora S. Nóbrega
- University Hospital of Federal University of Santa Catarina (HU/UFSC); Florianópolis-SC Brazil
| | | | - Elaine Paulin
- Health and Sports Science Centre; Santa Catarina State University (CEFID/UDESC); Florianópolis-SC Brazil
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Yu JI, Kim JS, Park HC, Lim DH, Han YY, Lim HC, Paik SW. Evaluation of anatomical landmark position differences between respiration-gated MRI and four-dimensional CT for radiation therapy in patients with hepatocellular carcinoma. Br J Radiol 2013; 86:20120221. [PMID: 23239694 DOI: 10.1259/bjr.20120221] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
OBJECTIVE To measure the accuracy of position differences in anatomical landmarks in gated MRI and four-dimensional CT (4D-CT) fusion planning for radiation therapy in patients with hepatocellular carcinoma (HCC). METHODS From April to December 2009, gated MR and planning 4D-CT images were obtained from 53 inoperable HCC patients accrued to this study. Gated MRI and planning 4D-CT were conducted on the same day. Manual image fusions were performed by matching the vertebral bodies. Liver volumes and three specific anatomical landmarks (portal vein conjunction, superior mesenteric artery bifurcation, and other noticeable points) were contoured from each modality. The points chosen nearest the centre of the four landmark points were compared to measure the accuracy of fusion. RESULTS The average distance differences (±standard deviation) of four validation points were 5.1 mm (±4.6 mm), 5.6 mm (±6.2 mm), 5.4 mm (±4.5 mm) and 5.1 mm (±4.8 mm). Patients who had ascites or pulmonary disease showed larger discrepancies. MRI-CT fusion discrepancy was significantly correlated with positive radiation response (p<0.05). CONCLUSIONS Approximately 5-mm anatomical landmark positional differences in all directions were found between gated MRI and 4D-CT fusion planning for HCC patients; the gap was larger in patients with ascites or pulmonary disease. ADVANCES IN KNOWLEDGE There were discrepancies of approximately 5 mm in gated MRI-CT fusion planning for HCC patients.
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Affiliation(s)
- J I Yu
- Department of Radiation Oncology, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
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Introduction to 4D Motion Modeling and 4D Radiotherapy. 4D MODELING AND ESTIMATION OF RESPIRATORY MOTION FOR RADIATION THERAPY 2013. [DOI: 10.1007/978-3-642-36441-9_1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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