1
|
Bal SS, Yang FPG, Chi NF, Yin JH, Wang TJ, Peng GS, Chen K, Hsu CC, Chen CI. Core and penumbra estimation using deep learning-based AIF in association with clinical measures in computed tomography perfusion (CTP). Insights Imaging 2023; 14:161. [PMID: 37775600 PMCID: PMC10541385 DOI: 10.1186/s13244-023-01472-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 06/23/2023] [Indexed: 10/01/2023] Open
Abstract
OBJECTIVES To investigate whether utilizing a convolutional neural network (CNN)-based arterial input function (AIF) improves the volumetric estimation of core and penumbra in association with clinical measures in stroke patients. METHODS The study included 160 acute ischemic stroke patients (male = 87, female = 73, median age = 73 years) with approval from the institutional review board. The patients had undergone CTP imaging, NIHSS and ASPECTS grading. convolutional neural network (CNN) model was trained to fit a raw AIF curve to a gamma variate function. CNN AIF was utilized to estimate the core and penumbra volumes which were further validated with clinical scores. RESULTS Penumbra estimated by CNN AIF correlated positively with the NIHSS score (r = 0.69; p < 0.001) and negatively with the ASPECTS (r = - 0.43; p < 0.001). The CNN AIF estimated penumbra and core volume matching the patient symptoms, typically in patients with higher NIHSS (> 20) and lower ASPECT score (< 5). In group analysis, the median CBF < 20%, CBF < 30%, rCBF < 38%, Tmax > 10 s, Tmax > 10 s volumes were statistically significantly higher (p < .05). CONCLUSIONS With inclusion of the CNN AIF in perfusion imaging pipeline, penumbra and core estimations are more reliable as they correlate with scores representing neurological deficits in stroke. CRITICAL RELEVANCE STATEMENT With CNN AIF perfusion imaging pipeline, penumbra and core estimations are more reliable as they correlate with scores representing neurological deficits in stroke.
Collapse
Affiliation(s)
- Sukhdeep Singh Bal
- Department of Mathematical Sciences, University of Liverpool, Liverpool, Merseyside, UK
- Center for Cognition and Mind Sciences, National Tsing Hua University, Hsinchu, Taiwan
| | - Fan-Pei Gloria Yang
- Center for Cognition and Mind Sciences, National Tsing Hua University, Hsinchu, Taiwan.
- Department of Foreign Languages and Literature, National Tsing Hua University, Hsinchu, Taiwan.
- Department of Radiology, Graduate School of Dentistry, Osaka University, Suita, Japan.
| | - Nai-Fang Chi
- Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Jiu Haw Yin
- Department of Neurology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Tao-Jung Wang
- Department of Computer Science, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
| | - Giia Sheun Peng
- Department of Neurology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
- Division of Neurology, Department of Internal Medicine, Taipei Veterans General Hospital, Hsinchu Branch, Hsinchu County, Taipei, Taiwan
| | - Ke Chen
- Department of Mathematical Sciences, University of Liverpool, Liverpool, Merseyside, UK
| | - Ching-Chi Hsu
- Board of Directors, Wizcare Medical Corporation Aggregate, Taichung, Taiwan
| | - Chang-I Chen
- Department of Medical Management, Taipei Medical University, Taipei, Taiwan
| |
Collapse
|
2
|
Optimal Scaling Approaches for Perfusion MRI with Distorted Arterial Input Function (AIF) in Patients with Ischemic Stroke. Brain Sci 2022; 12:brainsci12010077. [PMID: 35053820 PMCID: PMC8774085 DOI: 10.3390/brainsci12010077] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 12/17/2021] [Accepted: 12/30/2021] [Indexed: 11/19/2022] Open
Abstract
Background: Diagnosis and timely treatment of ischemic stroke depends on the fast and accurate quantification of perfusion parameters. Arterial input function (AIF) describes contrast agent concentration over time as it enters the brain through the brain feeding artery. AIF is the central quantity required to estimate perfusion parameters. Inaccurate and distorted AIF, due to partial volume effects (PVE), would lead to inaccurate quantification of perfusion parameters. Methods: Fifteen patients suffering from stroke underwent perfusion MRI imaging at the Tri-Service General Hospital, Taipei. Various degrees of the PVE were induced on the AIF and subsequently corrected using rescaling methods. Results: Rescaled AIFs match the exact reference AIF curve either at peak height or at tail. Inaccurate estimation of CBF values estimated from non-rescaled AIFs increase with increasing PVE. Rescaling of the AIF using all three approaches resulted in reduced deviation of CBF values from the reference CBF values. In most cases, CBF map generated by rescaled AIF approaches show increased CBF and Tmax values on the slices in the left and right hemispheres. Conclusion: Rescaling AIF by VOF approach seems to be a robust and adaptable approach for correction of the PVE-affected multivoxel AIF. Utilizing an AIF scaling approach leads to more reasonable absolute perfusion parameter values, represented by the increased mean CBF/Tmax values and CBF/Tmax images.
Collapse
|
3
|
Lind E, Knutsson L, Ståhlberg F, Wirestam R. Dynamic contrast-enhanced QSM for perfusion imaging: a systematic comparison of ΔR2*- and QSM-based contrast agent concentration time curves in blood and tissue. MAGMA (NEW YORK, N.Y.) 2020; 33:663-676. [PMID: 32078074 PMCID: PMC7502058 DOI: 10.1007/s10334-020-00831-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 01/23/2020] [Accepted: 01/28/2020] [Indexed: 11/28/2022]
Abstract
OBJECTIVE In dynamic susceptibility contrast MRI (DSC-MRI), an arterial input function (AIF) is required to quantify perfusion. However, estimation of the concentration of contrast agent (CA) from magnitude MRI signal data is challenging. A reasonable alternative would be to quantify CA concentration using quantitative susceptibility mapping (QSM), as the CA alters the magnetic susceptibility in proportion to its concentration. MATERIAL AND METHODS AIFs with reasonable appearance, selected on the basis of conventional criteria related to timing, shape, and peak concentration, were registered from both ΔR2* and QSM images and mutually compared by visual inspection. Both ΔR2*- and QSM-based AIFs were used for perfusion calculations based on tissue concentration data from ΔR2*as well as QSM images. RESULTS AIFs based on ΔR2* and QSM data showed very similar shapes and the estimated cerebral blood flow values and mean transit times were similar. Analysis of corresponding ΔR2* versus QSM-based concentration estimates yielded a transverse relaxivity estimate of 89 s-1 mM-1, for voxels identified as useful AIF candidate in ΔR2* images according to the conventional criteria. DISCUSSION Interestingly, arterial concentration time curves based on ΔR2* versus QSM data, for a standard DSC-MRI experiment, were generally very similar in shape, and the relaxivity obtained in voxels representing blood was similar to tissue relaxivity obtained in previous studies.
Collapse
Affiliation(s)
- Emelie Lind
- Department of Medical Radiation Physics, Lund University, Barngatan 4, 22185, Lund, Sweden.
| | - Linda Knutsson
- Department of Medical Radiation Physics, Lund University, Barngatan 4, 22185, Lund, Sweden.,Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Freddy Ståhlberg
- Department of Medical Radiation Physics, Lund University, Barngatan 4, 22185, Lund, Sweden.,Department of Clinical Sciences Lund, Diagnostic Radiology, Lund, Sweden.,Lund University Bioimaging Center, Lund University, Lund, Sweden
| | - Ronnie Wirestam
- Department of Medical Radiation Physics, Lund University, Barngatan 4, 22185, Lund, Sweden
| |
Collapse
|
4
|
van Zijl P, Knutsson L. In vivo magnetic resonance imaging and spectroscopy. Technological advances and opportunities for applications continue to abound. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2019; 306:55-65. [PMID: 31377150 PMCID: PMC6703925 DOI: 10.1016/j.jmr.2019.07.034] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 06/19/2019] [Accepted: 07/08/2019] [Indexed: 05/07/2023]
Abstract
Over the past decades, the field of in vivo magnetic resonance (MR) has built up an impressive repertoire of data acquisition and analysis technologies for anatomical, functional, physiological, and molecular imaging, the description of which requires many book volumes. As such it is impossible for a few authors to have an authoritative overview of the field and for a brief article to be inclusive. We will therefore focus mainly on data acquisition and attempt to give some insight into the principles underlying current advanced methods in the field and the potential for further innovation. In our view, the foreseeable future is expected to show continued rapid progress, for instance in imaging of microscopic tissue properties in vivo, assessment of functional and anatomical connectivity, higher resolution physiologic and metabolic imaging, and even imaging of receptor binding. In addition, acquisition speed and information content will continue to increase due to the continuous development of approaches for parallel imaging (including simultaneous multi-slice imaging), compressed sensing, and MRI fingerprinting. Finally, artificial intelligence approaches are becoming more realistic and will have a tremendous effect on both acquisition and analysis strategies. Together, these developments will continue to provide opportunity for scientific discovery and, in combination with large data sets from other fields such as genomics, allow the ultimate realization of precision medicine in the clinic.
Collapse
Affiliation(s)
- Peter van Zijl
- Department of Radiology, Johns Hopkins University, F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA.
| | - Linda Knutsson
- Department of Medical Radiation Physics, Lund University, Lund, Sweden
| |
Collapse
|
5
|
Knutsson L, Xu X, Ståhlberg F, Barker PB, Lind E, Sundgren PC, van Zijl PCM, Wirestam R. Dynamic Susceptibility Contrast MRI at 7 T: Tail-Scaling Analysis and Inferences About Field Strength Dependence. Tomography 2017; 3:74-78. [PMID: 28825038 PMCID: PMC5558863 DOI: 10.18383/j.tom.2017.00001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) following bolus injection of gadolinium contrast agent (CA) is widely used for the estimation of brain perfusion parameters such as cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time (MTT) for both clinical and research purposes. Although it is predicted that DSC-MRI will have superior performance at high magnetic field strengths, to the best of our knowledge, there are no reports of 7 T DSC-MRI in the literature. It is plausible that the transfer of DSC-MRI to 7 T may be accompanied by increased R2* relaxivity in tissue and a larger difference in ΔR2*-versus-concentration relationships between tissue and large vessels. If not accounted for, this will subsequently result in apparent CBV and CBF estimates that are higher than those reported previously at lower field strengths. The aims of this study were therefore to assess the feasibility of 7 T DSC-MRI and to investigate the apparent field-strength dependence of CBV and CBF estimates. In total, 8 healthy volunteers were examined using DSC-MRI at 7 T. A reduced CA dose of 0.05 mmol/kg was administered to decrease susceptibility artifacts. CBV, CBF, and MTT maps were calculated using standard DSC-MRI tracer-kinetic theory. Subject-specific arterial partial volume correction factors were obtained using a tail-scaling approach. Compared with literature values obtained using the tail-scaling approach at 1.5 T and 3 T, the CBV and CBF values of the present study were found to be further overestimated. This observation is potentially related to an inferred field-strength dependence of transverse relaxivities, although issues related to the CA dose must also be considered.
Collapse
Affiliation(s)
- Linda Knutsson
- Department of Medical Radiation Physics, Lund University, Lund, Sweden.,Department of Radiology (Adjunct), Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Xiang Xu
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland.,F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland
| | - Freddy Ståhlberg
- Department of Medical Radiation Physics, Lund University, Lund, Sweden.,Department of Diagnostic Radiology, Lund University, Lund, Sweden.,Lund University Bioimaging Center, Lund University, Lund, Sweden
| | - Peter B Barker
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland.,F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland
| | - Emelie Lind
- Department of Medical Radiation Physics, Lund University, Lund, Sweden
| | - Pia C Sundgren
- Department of Diagnostic Radiology, Lund University, Lund, Sweden
| | - Peter C M van Zijl
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland.,F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland
| | - Ronnie Wirestam
- Department of Medical Radiation Physics, Lund University, Lund, Sweden
| |
Collapse
|
6
|
Automated Determination of Arterial Input Function for Dynamic Susceptibility Contrast MRI from Regions around Arteries Using Independent Component Analysis. Radiol Res Pract 2016; 2016:2657405. [PMID: 27547451 PMCID: PMC4980584 DOI: 10.1155/2016/2657405] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 05/05/2016] [Accepted: 05/24/2016] [Indexed: 11/18/2022] Open
Abstract
Purpose. Quantitative cerebral blood flow (CBF) measurement using dynamic susceptibility contrast- (DSC-) MRI requires accurate estimation of the arterial input function (AIF). The present work utilized the independent component analysis (ICA) method to determine the AIF in the regions adjacent to the middle cerebral artery (MCA) by the alleviated confounding of partial volume effect. Materials and Methods. A series of spin-echo EPI MR scans were performed in 10 normal subjects. All subjects received 0.2 mmol/kg Gd-DTPA contrast agent. AIFs were calculated by two methods: (1) the region of interest (ROI) selected manually and (2) weighted average of each component selected by ICA (weighted-ICA). The singular value decomposition (SVD) method was then employed to deconvolve the AIF from the tissue concentration time curve to obtain quantitative CBF values. Results. The CBF values calculated by the weighted-ICA method were 41.1 ± 4.9 and 22.1 ± 2.3 mL/100 g/min for cortical gray matter (GM) and deep white matter (WM) regions, respectively. The CBF values obtained based on the manual ROIs were 53.6 ± 12.0 and 27.9 ± 5.9 mL/100 g/min for the same two regions, respectively. Conclusion. The weighted-ICA method allowed semiautomatic and straightforward extraction of the ROI adjacent to MCA. Through eliminating the partial volume effect to minimum, the CBF thus determined may reflect more accurate physical characteristics of the T2(⁎) signal changes induced by the contrast agent.
Collapse
|
7
|
Ahlgren A, Wirestam R, Lind E, Ståhlberg F, Knutsson L. A linear mixed perfusion model for tissue partial volume correction of perfusion estimates in dynamic susceptibility contrast MRI: Impact on absolute quantification, repeatability, and agreement with pseudo-continuous arterial spin labeling. Magn Reson Med 2016; 77:2203-2214. [PMID: 27321696 DOI: 10.1002/mrm.26305] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 05/20/2016] [Accepted: 05/20/2016] [Indexed: 11/07/2022]
Abstract
PURPOSE The partial volume effect (PVE) is an important source of bias in brain perfusion measurements. The impact of tissue PVEs in perfusion measurements with dynamic susceptibility contrast MRI (DSC-MRI) has not yet been well established. The purpose of this study was to suggest a partial volume correction (PVC) approach for DSC-MRI and to study how PVC affects DSC-MRI perfusion results. METHODS A linear mixed perfusion model for DSC-MRI was derived and evaluated by way of simulations. Twenty healthy volunteers were scanned twice, including DSC-MRI, arterial spin labeling (ASL), and partial volume measurements. Two different algorithms for PVC were employed and assessed. RESULTS Simulations showed that the derived model had a tendency to overestimate perfusion values in voxels with high fractions of cerebrospinal fluid. PVC reduced the tissue volume dependence of DSC-MRI perfusion values from 44.4% to 4.2% in gray matter and from 55.3% to 14.2% in white matter. One PVC method significantly improved the voxel-wise repeatability, but PVC did not improve the spatial agreement between DSC-MRI and ASL perfusion maps. CONCLUSION Significant PVEs were found for DSC-MRI perfusion estimates, and PVC successfully reduced those effects. The findings suggest that PVC might be an important consideration for DSC-MRI applications. Magn Reson Med 77:2203-2214, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
Collapse
Affiliation(s)
- André Ahlgren
- Department of Medical Radiation Physics, Lund University, Lund, Sweden
| | - Ronnie Wirestam
- Department of Medical Radiation Physics, Lund University, Lund, Sweden
| | - Emelie Lind
- Department of Medical Radiation Physics, Lund University, Lund, Sweden
| | - Freddy Ståhlberg
- Department of Medical Radiation Physics, Lund University, Lund, Sweden.,Department of Diagnostic Radiology, Lund University, Lund, Sweden.,Lund University Bioimaging Center, Lund University, Lund, Sweden
| | - Linda Knutsson
- Department of Medical Radiation Physics, Lund University, Lund, Sweden
| |
Collapse
|
8
|
Monti L, Donati D, Menci E, Cioni S, Bellini M, Grazzini I, Leonini S, Galluzzi P, Severi S, Burroni L, Casasco A, Morbidelli L, Santarnecchi E, Piu P. Cerebral circulation time is prolonged and not correlated with EDSS in multiple sclerosis patients: a study using digital subtracted angiography. PLoS One 2015; 10:e0116681. [PMID: 25679526 PMCID: PMC4334558 DOI: 10.1371/journal.pone.0116681] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2014] [Accepted: 11/13/2014] [Indexed: 12/23/2022] Open
Abstract
Literature has suggested that changes in brain flow circulation occur in patients with multiple sclerosis. In this study, digital subtraction angiography (DSA) was used to measure the absolute CCT value in MS patients and to correlate its value to age at disease onset and duration, and to expand disability status scale (EDSS). DSA assessment was performed on eighty MS patients and on a control group of forty-four age-matched patients. CCT in MS and control groups was calculated by analyzing the angiographic images. Lesion and brain volumes were calculated in a representative group of MS patients. Statistical correlations among CCT and disease duration, age at disease onset, lesion load, brain volumes and EDSS were considered. A significant difference between CCT in MS patients (mean = 4.9s; sd = 1.27s) and control group (mean = 2.8s; sd = 0.51s) was demonstrated. No significant statistical correlation was found between CCT and the other parameters in all MS patients. Significantly increased CCT value in MS patients suggests the presence of microvascular dysfunctions, which do not depend on clinical and MRI findings. Hemodynamic changes may not be exclusively the result of a late chronic inflammatory process.
Collapse
Affiliation(s)
- Lucia Monti
- Unit of Neuroimaging and Neurointervention, Department of Neurological and Sensorial Sciences Azienda Ospedaliera Universitaria Senese, Santa Maria alle Scotte General Hospital, Siena, Italy
- * E-mail:
| | - Donatella Donati
- Dept. of Medicine, Surgery & Neuroscience, University of Siena, Siena, Italy
| | - Elisabetta Menci
- Unit of Neuroimaging and Neurointervention, Department of Neurological and Sensorial Sciences Azienda Ospedaliera Universitaria Senese, Santa Maria alle Scotte General Hospital, Siena, Italy
| | - Samuele Cioni
- Unit of Neuroimaging and Neurointervention, Department of Neurological and Sensorial Sciences Azienda Ospedaliera Universitaria Senese, Santa Maria alle Scotte General Hospital, Siena, Italy
| | - Matteo Bellini
- Unit of Neuroimaging and Neurointervention, Department of Neurological and Sensorial Sciences Azienda Ospedaliera Universitaria Senese, Santa Maria alle Scotte General Hospital, Siena, Italy
| | - Irene Grazzini
- Unit of Neuroimaging and Neurointervention, Department of Neurological and Sensorial Sciences Azienda Ospedaliera Universitaria Senese, Santa Maria alle Scotte General Hospital, Siena, Italy
| | - Sara Leonini
- Unit of Neuroimaging and Neurointervention, Department of Neurological and Sensorial Sciences Azienda Ospedaliera Universitaria Senese, Santa Maria alle Scotte General Hospital, Siena, Italy
| | - Paolo Galluzzi
- Unit of Neuroimaging and Neurointervention, Department of Neurological and Sensorial Sciences Azienda Ospedaliera Universitaria Senese, Santa Maria alle Scotte General Hospital, Siena, Italy
| | - Sauro Severi
- Dept. of Neurology, General Hospital of “S. Donato d’Arezzo”, Arezzo, Italy
| | - Luca Burroni
- Unit of Nuclear Medicine, Azienda Ospedaliera Universitaria Senese, Santa Maria alle Scotte General Hospital, Siena, Italy
| | - Alfredo Casasco
- Unit of Endovascular and Percutaneous Therapy, Clinica Nuestra Senora del Rosario, Madrid, Spain
| | | | - Emiliano Santarnecchi
- Dept. of Medicine, Surgery & Neuroscience, University of Siena, Siena, Italy
- Berenson-Allen Center for Non-Invasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Pietro Piu
- Dept. of Medicine, Surgery & Neuroscience, University of Siena, Siena, Italy
| |
Collapse
|