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Torres Rojas AM, Lorente S. Liver fibrosis emulation: Impact of the vascular fibrotic alterations on hemodynamics. Comput Biol Med 2023; 166:107563. [PMID: 37852110 DOI: 10.1016/j.compbiomed.2023.107563] [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: 07/05/2023] [Revised: 09/10/2023] [Accepted: 10/10/2023] [Indexed: 10/20/2023]
Abstract
The liver circulatory system comprises two blood supply vascular trees (the hepatic artery and portal venous networks), microcirculation through the hepatic capillaries (the sinusoids), and a blood drainage vascular tree (the hepatic vein network). Vasculature changes due to fibrosis -located predominantly at the microcirculation level- lead to a marked increase in resistance to flow causing an increase in portal pressure (portal hypertension). Here, we present a liver fibrosis/cirrhosis model. We build on our 1D model of the healthy hepatic circulation, which considers the elasticity of the vessels walls and the pulsatile character of blood flow and pressure, and recreate the deteriorated liver vasculature due to fibrosis. We emulate altered sinusoids by fibrous tissue (stiffened, compressed and splitting) and propose boundary conditions to investigate the impact of fibrosis on hemodynamic variables within the organ. We obtain that the sinusoids stiffness leads to changes in the amplitude and shape of the blood flow and pressure waveforms but not in their mean value. For the compressed and splitting sinusoids, we observe significant increases in the mean value and amplitude of the pressure waveform in the altered sinusoids and in the portal venous network. In other words, we obtain the portal hypertension clinically observed in fibrotic/cirrhotic patients. We also study the extent of the spreading fibrosis by performing the structural fibrotic changes in an increasingly number of sinusoids. Finally, we calculate the portal pressure gradient (PPG) in the model and obtain values in agreement with those reported in the literature for fibrotic/cirrhotic patients.
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Affiliation(s)
- Aimee M Torres Rojas
- Mechanical Engineering Department, Villanova University, 800 Lancaster Avenue, Villanova, PA, 19085, USA.
| | - Sylvie Lorente
- Mechanical Engineering Department, Villanova University, 800 Lancaster Avenue, Villanova, PA, 19085, USA
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2
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Huang A, Roberts GS, Roldán-Alzate A, Wieben O, Reeder SB, Oechtering TH. Reference values for 4D flow magnetic resonance imaging of the portal venous system. Abdom Radiol (NY) 2023; 48:2049-2059. [PMID: 37016247 PMCID: PMC10518803 DOI: 10.1007/s00261-023-03892-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Revised: 03/17/2023] [Accepted: 03/19/2023] [Indexed: 04/06/2023]
Abstract
PURPOSE The purpose of this work was to establish normal reference values for 4D flow MRI-derived flow, velocity, and vessel diameters, and to define characteristic flow patterns in the portal venous system of healthy adult subjects. METHODS For this retrospective study, we screened all available 4D flow MRI exams of the upper abdomen in healthy adults acquired at our institution between 2012 and 2022 at either 1.5 T or 3.0 T MRI after ≥ 5 h fasting. Flow, velocity, and effective diameter were quantified in the 8 planes in the portal venous system (splenic vein, superior mesenteric vein, main, right, and left portal veins). Vessel delineation was manually adjusted over time. Reference ranges for were defined as the mean ± 2 standard deviations. Three readers noted helical and vortical flow on time-resolved pathline visualizations. Conservation of mass flow analysis was performed for quality assurance. RESULTS We included 44 healthy subjects (26 female, 18-74 years) in the analysis. We report reference values for mean and peak flow, mean velocity, and vessel diameter in the healthy portal vein using 4D flow MRI. Normal flow patterns in the portal vein included faint helical (66%) or linear flow (34%). Conservation of mass analysis demonstrated a relative error of 1.1 ± 4.6% standard deviation (SD) at the splenomesenteric confluence and - 1.4 ± 4.1% SD at the portal bifurcation. CONCLUSION We have reported normal hemodynamic values that are necessary baseline data for emerging clinical applications of 4D flow MRI in the portal venous system. Results are consistent with previously published values from smaller cohorts.
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Affiliation(s)
- Andrew Huang
- Department of Radiology, University of Wisconsin, Madison, WI, USA
- Section of Vascular Surgery, Department of Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Grant S Roberts
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Alejandro Roldán-Alzate
- Department of Mechanical Engineering, University of Wisconsin, Madison, WI, USA
- Department of Biomedical Engineering, University of Wisconsin, Madison, WI, USA
| | - Oliver Wieben
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Scott B Reeder
- Department of Radiology, University of Wisconsin, Madison, WI, USA
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
- Department of Biomedical Engineering, University of Wisconsin, Madison, WI, USA
- Department of Medicine, University of Wisconsin, Madison, WI, USA
- Department of Emergency Medicine, University of Wisconsin, Madison, WI, USA
| | - Thekla H Oechtering
- Department of Radiology, University of Wisconsin, Madison, WI, USA.
- Department of Radiology and Nuclear Medicine, Universität zu Lübeck, Lübeck, Germany.
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Hyodo R, Takehara Y, Naganawa S. 4D Flow MRI in the portal venous system: imaging and analysis methods, and clinical applications. Radiol Med 2022; 127:1181-1198. [PMID: 36123520 PMCID: PMC9587937 DOI: 10.1007/s11547-022-01553-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 08/29/2022] [Indexed: 02/07/2023]
Abstract
Thus far, ultrasound, CT, and 2D cine phase-contrast MRI has been adopted to evaluate blood flow and vascular morphology in the portal venous system; however, all these techniques have some shortcomings, such as limited field of view and difficulty in accurately evaluating blood flow. A new imaging technique, namely 3D cine phase-contrast (4D Flow) MRI, can acquire blood flow data of the entire abdomen at once and in a time-resolved manner, allowing visual, quantitative, and comprehensive assessment of blood flow in the portal venous system. In addition, a retrospective blood flow analysis, i.e., "retrospective flowmetry," is possible. Although the development of 4D Flow MRI for the portal system has been delayed compared to that for the arterial system owing to the lower flow velocity of the portal venous system and the presence of respiratory artifacts, several useful reports have recently been published as the technology has advanced. In the first part of this narrative review article, technical considerations of image acquisition and analysis methods of 4D Flow MRI for the portal venous system and the validations of their results are described. In the second part, the current clinical application of 4D Flow MRI for the portal venous system is reviewed.
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Affiliation(s)
- Ryota Hyodo
- Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan.
| | - Yasuo Takehara
- Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan
- Department of Fundamental Development for Advanced Low Invasive Diagnostic Imaging, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Shinji Naganawa
- Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan
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4
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Hai Y, Chong W, Eisenbrey JR, Forsberg F. Network Meta-Analysis: Noninvasive Imaging Modalities for Identifying Clinically Significant Portal Hypertension. Dig Dis Sci 2022; 67:3313-3326. [PMID: 34275089 PMCID: PMC8761784 DOI: 10.1007/s10620-021-07168-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 07/07/2021] [Indexed: 12/16/2022]
Abstract
BACKGROUND Although measurement of the hepatic venous pressure gradient (HVPG) is the current reference standard for obtaining portal venous pressures, several noninvasive imaging-based modalities have been proposed as alternatives. AIMS We performed a systematic review and meta-analysis to compare the diagnostic accuracy of noninvasive imaging approaches for identifying clinically significant portal hypertension (CSPH). METHODS Two independent reviewers conducted a literature search of PubMed, SCOPUS, and the Cochrane Library from inception until January 5, 2021. The following imaging modalities were compared to HVPG: computed tomography (CT), magnetic resonance imaging (MRI), magnetic resonance elastography, ultrasound, transient elastography (TE), shear wave elastography (SWE), acoustic radiation force impulse (ARFI) imaging, contrast-enhanced ultrasound (CEUS), and subharmonic-aided pressure estimation (SHAPE). Sensitivity, specificity, diagnostic odds ratio (DOR), and area under the curve (AUC) for summary receiver operating characteristic were calculated using both frequentist random effects and Bayesian network meta-analytic approaches. RESULTS We analyzed 45 studies of 5678 patients. A broad overlapping confidence interval (CI) of DOR was observed among different imaging modalities: ARFI (30.5; 95% CI 12.7-73.3), CEUS and SHAPE (21.1; 95% CI 6.4-69.8), TE of liver stiffness (21.1; 95% CI 13.3-33.5), CT and MRI (13.7; 95% CI 7.40-25.4), SWE of liver stiffness (10.5; 95% CI 5.2-21.1), and ultrasound (9.5; 95% CI 4.9-18.4). The AUC of all imaging methods exceeded 0.8, indicating very good performance. At a cutoff of 80% specificity, TE, CEUS, and SHAPE exceeded 80% sensitivity. CONCLUSION Overall, noninvasive imaging modalities perform well for identifying CSPH. Clinicians should consider these noninvasive and cost-efficient tests when diagnosing CSPH.
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Affiliation(s)
- Yang Hai
- Department of Radiology, Thomas Jefferson University, 132 South 10th Street, Suite 763 H, Main Building, Philadelphia, PA, 19107, USA
| | - Weelic Chong
- Department of Radiology, Thomas Jefferson University, 132 South 10th Street, Suite 763 H, Main Building, Philadelphia, PA, 19107, USA
| | - John R Eisenbrey
- Department of Radiology, Thomas Jefferson University, 132 South 10th Street, Suite 763 H, Main Building, Philadelphia, PA, 19107, USA
| | - Flemming Forsberg
- Department of Radiology, Thomas Jefferson University, 132 South 10th Street, Suite 763 H, Main Building, Philadelphia, PA, 19107, USA.
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5
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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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Abou-Arab O, Beyls C, Moussa MD, Huette P, Beaudelot E, Guilbart M, De Broca B, Yzet T, Dupont H, Bouzerar R, Mahjoub Y. Portal Vein Pulsatility Index as a Potential Risk of Venous Congestion Assessed by Magnetic Resonance Imaging: A Prospective Study on Healthy Volunteers. Front Physiol 2022; 13:811286. [PMID: 35574483 PMCID: PMC9101294 DOI: 10.3389/fphys.2022.811286] [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] [Received: 11/08/2021] [Accepted: 03/18/2022] [Indexed: 11/25/2022] Open
Abstract
High values of the portal vein pulsatility index (PI) have been associated with adverse outcomes in perioperative or critically ill patients. However, data on dynamic changes of PI related to fluid infusion are scarce. We aimed to determine if dynamic changes in PI are associated with the fluid challenge (FC). To address this challenge, we conducted a prospective single-center study. The population study included healthy subjects. FC consisted in the administration of 500 ml of Ringer lactate infusion over 5 min. The portal blood flow and PI were assessed by magnetic resonance imaging. The responsiveness to FC was defined as an increase in the cardiac stroke volume of at least 10% as assessed by echocardiography. We included 24 healthy volunteers. A total of fourteen (58%) subjects were responders, and 10 (42%) were non-responders. In the responder group, FC induced a significant increase in portal blood flow from 881 (762–1,001) at the baseline to 1,010 (778–1,106) ml min−1 (p = 0.005), whilst PI remained stable (from 31 [25–41] to 35 (25–42) %; p = 0.12). In the non-responder group, portal blood flow remained stable after FC (from 1,042 to 1,034 ml min−1; p = 0.084), whereas PI significantly increased from 32 (22–40) to 48% *(25–85) after FC (p = 0.027). PI was negatively correlated to portal blood flow (Rho coefficient = −0.611; p = 0.002). To conclude, PI might be a sensitive marker of early congestion in healthy subjects that did not respond to FC. This finding requires further validation in clinical settings with a larger sample size.
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Affiliation(s)
- Osama Abou-Arab
- Anesthesia and Critical Care Department, Amiens Hospital University, Amiens, France
- *Correspondence: Osama Abou-Arab,
| | - Christophe Beyls
- Anesthesia and Critical Care Department, Amiens Hospital University, Amiens, France
| | | | - Pierre Huette
- Anesthesia and Critical Care Department, Amiens Hospital University, Amiens, France
| | - Elodie Beaudelot
- Anesthesia and Critical Care Department, Amiens Hospital University, Amiens, France
| | - Mathieu Guilbart
- Anesthesia and Critical Care Department, Amiens Hospital University, Amiens, France
| | - Bruno De Broca
- Anesthesia and Critical Care Department, Amiens Hospital University, Amiens, France
| | - Thierry Yzet
- Department of Radiology, Amiens Picardy University Hospital, Amiens, France
| | - Hervé Dupont
- Anesthesia and Critical Care Department, Amiens Hospital University, Amiens, France
| | - Roger Bouzerar
- Department of Biophysics and image processing, Amiens Picardy University Hospital, Amiens, France
| | - Yazine Mahjoub
- Anesthesia and Critical Care Department, Amiens Hospital University, Amiens, France
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Kadoya Y, Miyati T, Kobayashi S, Ohno N, Gabata T. Evaluation of gravity effect on inferior vena cava and abdominal aortic flow using multi-posture MRI. Acta Radiol 2021; 62:1122-1128. [PMID: 32799558 DOI: 10.1177/0284185120950112] [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] [Indexed: 11/17/2022]
Abstract
BACKGROUND Inferior vena cava flow (IVCF) and abdominal aortic flow (AAF) are essential components of the systemic circulation. Although postural changes might alter IVCF and AAF by the gravity effect, the exact details are unknown. PURPOSE To evaluate the effect of gravity on IVCF and AAF using a novel magnetic resonance imaging (MRI) system that can image in any position. MATERIAL AND METHODS Caval velocity-mapped images were obtained using the cine phase-contrast technique in the upright and supine positions with multi-posture MRI (n = 12). The mean IVCF/AAF velocity, maximum IVCF/AAF velocity, cross-sectional area of IVC/AA, mean IVCF/AAF, maximum IVCF/AAF, and heart rate in the two positions were assessed. RESULTS The mean IVCF velocity, maximum IVCF velocity, cross-sectional area of IVC, mean IVCF, maximum IVCF, mean AAF velocity, maximum AAF velocity, mean AAF, and maximum AAF were significantly lower in the upright position compared with the supine position (P < 0.05 for all), with differences of 52% ± 33%, 36% ± 19%, 56% ± 18%, 26% ± 18%, 19% ± 11%, 33% ± 13%, 33% ± 22%, 42% ± 21%, and 37% ± 28%, respectively. Heart rate was significantly higher in the upright position compared with the supine position (116% ± 9.2%; P = 0.003). There were no differences in cross-sectional area of AA between the two positions (108% ± 22%; P = 0.583). CONCLUSION The effect of gravity decreases IVCF and AAF. Clarifying the effect of gravity on IVCF and AAF during a postural change may help to improve the management of patients with circulatory disease.
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Affiliation(s)
- Yoshisuke Kadoya
- Department of Radiology, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Japan
- Department of Diagnostic Imaging, The Cancer Institute Hospital of JFCR, Tokyo, Japan
| | - Tosiaki Miyati
- Department of Quantum Medical Imaging, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Japan
| | - Satoshi Kobayashi
- Department of Quantum Medical Imaging, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Japan
| | - Naoki Ohno
- Department of Quantum Medical Imaging, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Japan
| | - Toshifumi Gabata
- Department of Radiology, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Japan
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Corrado PA, Medero R, Johnson KM, François CJ, Roldán-Alzate A, Wieben O. A phantom study comparing radial trajectories for accelerated cardiac 4D flow MRI against a particle imaging velocimetry reference. Magn Reson Med 2021; 86:363-371. [PMID: 33547658 PMCID: PMC8109233 DOI: 10.1002/mrm.28698] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 12/18/2020] [Accepted: 01/05/2021] [Indexed: 12/23/2022]
Abstract
PURPOSE Radial sampling is one method to accelerate 4D flow MRI acquisition, making feasible dual-velocity encoding (Venc) assessment of slow flow in the left ventricle (LV). Here, two radial trajectories are compared in vitro for this application: 3D radial (phase-contrast vastly undersampled isotropic projection, PC-VIPR) versus stack of stars (phase-contrast stack of stars, PC-SOS), with benchtop particle imaging velocimetry (PIV) serving as a reference standard. METHODS The study contained three steps: (1) Construction of an MRI- and PIV-compatible LV model from a healthy adult's CT images. (2) In vitro PIV using a pulsatile flow pump. (3) In vitro dual-Venc 4D flow MRI using PC-VIPR and PC-SOS (two repeat experiments). Each MR image set was retrospectively undersampled to five effective scan durations and compared with the PIV reference. The root-mean-square velocity vector difference (RMSE) between MRI and PIV images was compared, along with kinetic energy (KE) and wall shear stress (WSS). RESULTS RMSE increased as scan time decreased for both MR acquisitions. RMSE was 3% lower in PC-SOS images than PC-VIPR images in 30-min scans (3.8 vs. 3.9 cm/s) but 98% higher in 2.5-min scans (9.5 vs. 4.8 cm/s). PIV intrasession repeatability showed a RMSE of 4.4 cm/s, reflecting beat-to-beat flow variation, while MRI had intersession RMSEs of 3.8/3.5 cm/s for VIPR/SOS, respectively. Speed, KE, and WSS were overestimated voxel-wise in 30-min MRI scans relative to PIV by 0.4/0.3 cm/s, 0.2/0.1 μJ/mL, and 36/43 mPa, respectively, for VIPR/SOS. CONCLUSIONS PIV is feasible for application-specific 4D flow MRI protocol optimization. PC-VIPR is better-suited to dual-Venc LV imaging with short scan times.
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Affiliation(s)
- Philip A Corrado
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Rafael Medero
- Department of Mechanical Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Kevin M Johnson
- Departments of Medical Physics and Radiology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | | | - Alejandro Roldán-Alzate
- Departments of Mechanical and Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Oliver Wieben
- Departments of Medical Physics and Radiology, University of Wisconsin-Madison, Madison, Wisconsin, USA
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9
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Brunsing RL, Brown D, Almahoud H, Kono Y, Loomba R, Vodkin I, Sirlin CB, Alley MT, Vasanawala SS, Hsiao A. Quantification of the Hemodynamic Changes of Cirrhosis with Free-Breathing Self-Navigated MRI. J Magn Reson Imaging 2021; 53:1410-1421. [PMID: 33594733 PMCID: PMC9161739 DOI: 10.1002/jmri.27488] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 12/08/2020] [Accepted: 12/10/2020] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Non-invasive assessment of the hemodynamic changes of cirrhosis might help guide management of patients with liver disease but are currently limited. PURPOSE To determine whether free-breathing 4D flow MRI can be used to quantify the hemodynamic effects of cirrhosis and introduce hydraulic circuit indexes of severity. STUDY TYPE Retrospective. POPULATION Forty-seven patients including 26 with cirrhosis. FIELD STRENGTH/SEQUENCE 3 T/free-breathing 4D flow MRI with soft gating and golden-angle view ordering. ASSESSMENT Measurements of the supra-celiac abdominal aorta, supra-renal abdominal aorta (SRA), celiac trunk (CeT), superior mesenteric artery (SMA), splenic artery (SpA), common hepatic artery (CHA), portal vein (PV), and supra-renal inferior vena cava (IVC) were made by two radiologists. Measures of hepatic vascular resistance (hepatic arterial relative resistance [HARR]; portal resistive index [PRI]) were proposed and calculated. STATISTICAL ANALYSIS Bland-Altman, Pearson's correlation, Tukey's multiple comparison, and Cohen's kappa. P < 0.05 was considered significant. RESULTS Forty-four of 47 studies yielded adequate image quality for flow quantification (94%). Arterial structures showed high inter-reader concordance (range; ρ = 0.948-0.987) and the IVC (ρ = 0.972), with moderate concordance in the PV (ρ = 0.866). Conservation of mass analysis showed concordance between large vessels (SRA vs. IVC; ρ = 0.806), small vessels (celiac vs. CHA + SpA; ρ = 0.939), and across capillary beds (CeT + SMA vs. PV; ρ = 0.862). Splanchnic flow was increased in patients with portosystemic shunting (PSS) relative to control patients and patients with cirrhosis without PSS (P < 0.05, difference range 0.11-0.68 liter/m). HARR was elevated and PRI was decreased in patients with PSS (3.55 and 1.49, respectively) compared to both the control (2.11/3.18) and non-PSS (2.11/2.35) cohorts. DATA CONCLUSION 4D flow MRI with self-navigation was technically feasible, showing promise in quantifying the hemodynamic effects of cirrhosis. Proposed quantitative metrics of hepatic vascular resistance correlated with PSS. LEVEL OF EVIDENCE 3 TECHNICAL EFFICACY STAGE: 2.
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Affiliation(s)
- Ryan L Brunsing
- Department of Radiology, Stanford University, Palo Alto, California, USA
| | - Dustin Brown
- Department of Radiology, University of California San Diego, La Jolla, California, USA
| | - Hashem Almahoud
- Department of Radiology, University of California San Diego, La Jolla, California, USA
| | - Yuko Kono
- Department of Radiology, Stanford University, Palo Alto, California, USA
- Division of Gastroenterology, Department of Medicine, University of California San Diego, La Jolla, California, USA
| | - Rohit Loomba
- Division of Gastroenterology, Department of Medicine, University of California San Diego, La Jolla, California, USA
- Division of Epidemiology, Department of Family Medicine and Preventive Medicine, University of California San Diego, La Jolla, California, USA
- NAFLD Research Center, Department of Medicine, University of California San Diego, La Jolla, California, USA
| | - Irene Vodkin
- Division of Gastroenterology, Department of Medicine, University of California San Diego, La Jolla, California, USA
| | - Claude B Sirlin
- Department of Radiology, University of California San Diego, La Jolla, California, USA
| | - Marcus T Alley
- Department of Radiology, Stanford University, Palo Alto, California, USA
| | | | - Albert Hsiao
- Department of Radiology, University of California San Diego, La Jolla, California, USA
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10
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Williams G, Thyagaraj S, Fu A, Oshinski J, Giese D, Bunck AC, Fornari E, Santini F, Luciano M, Loth F, Martin BA. In vitro evaluation of cerebrospinal fluid velocity measurement in type I Chiari malformation: repeatability, reproducibility, and agreement using 2D phase contrast and 4D flow MRI. Fluids Barriers CNS 2021; 18:12. [PMID: 33736664 PMCID: PMC7977612 DOI: 10.1186/s12987-021-00246-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 03/03/2021] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Phase contrast magnetic resonance imaging, PC MRI, is a valuable tool allowing for non-invasive quantification of CSF dynamics, but has lacked adoption in clinical practice for Chiari malformation diagnostics. To improve these diagnostic practices, a better understanding of PC MRI based measurement agreement, repeatability, and reproducibility of CSF dynamics is needed. METHODS An anatomically realistic in vitro subject specific model of a Chiari malformation patient was scanned three times at five different scanning centers using 2D PC MRI and 4D Flow techniques to quantify intra-scanner repeatability, inter-scanner reproducibility, and agreement between imaging modalities. Peak systolic CSF velocities were measured at nine axial planes using 2D PC MRI, which were then compared to 4D Flow peak systolic velocity measurements extracted at those exact axial positions along the model. RESULTS Comparison of measurement results showed good overall agreement of CSF velocity detection between 2D PC MRI and 4D Flow (p = 0.86), fair intra-scanner repeatability (confidence intervals ± 1.5 cm/s), and poor inter-scanner reproducibility. On average, 4D Flow measurements had a larger variability than 2D PC MRI measurements (standard deviations 1.83 and 1.04 cm/s, respectively). CONCLUSION Agreement, repeatability, and reproducibility of 2D PC MRI and 4D Flow detection of peak CSF velocities was quantified using a patient-specific in vitro model of Chiari malformation. In combination, the greatest factor leading to measurement inconsistency was determined to be a lack of reproducibility between different MRI centers. Overall, these findings may help lead to better understanding for application of 2D PC MRI and 4D Flow techniques as diagnostic tools for CSF dynamics quantification in Chiari malformation and related diseases.
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Affiliation(s)
- Gwendolyn Williams
- Department of Chemical and Biological Engineering, University of Idaho, 875 Perimeter Dr. MC1122, Moscow, ID, 83844, USA
| | - Suraj Thyagaraj
- Department of Mechanical Engineering, Conquer Chiari Research Center, University of Akron, Akron, OH, 44325, USA
| | - Audrey Fu
- Department of Mathematics and Statistical Science, University of Idaho, Moscow, ID, 83844, USA
| | - John Oshinski
- Department of Radiology and Imaging Sciences, Emory University, Atlanta, GA, 30322, USA
| | - Daniel Giese
- Department of Radiology, University Hospital of Cologne, Cologne, Germany
| | - Alexander C Bunck
- Department of Radiology, University Hospital of Cologne, Cologne, Germany
| | - Eleonora Fornari
- CIBM, Department of Radiology, Centre Hospitalier Universitaire Vaudois (CHUV) and University of Lausanne, Lausanne, Switzerland
| | - Francesco Santini
- Division of Radiological Physics, Department of Radiology, University Hospital of Basel, Basel, Switzerland
- Department of Biomedical Engineering, University of Basel, Allschwil, Switzerland
| | - Mark Luciano
- Department of Neurosurgery, John Hopkins University, Baltimore, MD, USA
| | - Francis Loth
- Department of Mechanical Engineering, Conquer Chiari Research Center, University of Akron, Akron, OH, 44325, USA
| | - Bryn A Martin
- Department of Chemical and Biological Engineering, University of Idaho, 875 Perimeter Dr. MC1122, Moscow, ID, 83844, USA.
- Alcyone Therapeutics Inc, Lowell, MA, USA.
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11
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Qin S, Chen R, Wu B, Shiu WS, Cai XC. Numerical Simulation of Blood Flows in Patient-specific Abdominal Aorta with Primary Organs. Biomech Model Mechanobiol 2021; 20:909-924. [PMID: 33582934 DOI: 10.1007/s10237-021-01419-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 01/06/2021] [Indexed: 11/29/2022]
Abstract
The abdominal aorta is the largest artery in the abdominal cavity that supplies blood flows to vital organs through the complex visceral arterial branches, including the celiac trunk (the liver, stomach, spleen, etc.), the renal arteries (the kidneys) and the superior and inferior mesenteric arteries (the small and large intestine, pancreas, etc.). An accurate simulation of blood flows in this network of arteries is important for the understanding of the hemodynamics in various organs of healthy and diseased patients, but the computational cost is very high. As a result, most researchers choose to focus on a portion of the artery or use a low-dimensional approximation of the artery. In the present work, we introduce a parallel algorithm for the modeling of pulsatile flows in the abdominal aorta with branches to the primary organs, and an organ-based two-level method for calculating the resistances for the outflow boundary conditions. With this highly parallel approach, the simulation of the blood flow for a cardiac cycle of the anatomically detailed aorta can be obtained within a few hours, and the blood distribution to organs including liver, spleen and kidneys are also computed with certain accuracy. Moreover, we discuss the significant hemodynamic differences resulted from the influence of the peripheral branches. In addition, we examine the accuracy of the results with respect to the mesh size and time-step size and show the high parallel scalability of the proposed algorithm with up to 3000 processor cores.
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Affiliation(s)
- Shanlin Qin
- Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Rongliang Chen
- Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
- Shenzhen Key Laboratory for Exascale Engineering and Scientific Computing, Shenzhen, China
| | - Bokai Wu
- Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Wen-Shin Shiu
- Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Xiao-Chuan Cai
- Department of Mathematics, University of Macau, Macau, China.
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12
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Bomberna T, Koudehi GA, Claerebout C, Verslype C, Maleux G, Debbaut C. Transarterial drug delivery for liver cancer: numerical simulations and experimental validation of particle distribution in patient-specific livers. Expert Opin Drug Deliv 2020; 18:409-422. [PMID: 33210955 DOI: 10.1080/17425247.2021.1853702] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Background: Transarterial therapies are routinely used for the locoregional treatment of unresectable hepatocellular carcinoma (HCC). However, the impact of clinical parameters (i.e. injection location, particle size, particle density etc.) and patient-specific conditions (i.e. hepatic geometry, cancer burden) on the intrahepatic particle distribution (PD) after transarterial injection of embolizing microparticles is still unclear. Computational fluid dynamics (CFD) may help to better understand this impact.Methods: Using CFD, both the blood flow and microparticle mass transport were modeled throughout the 3D-reconstructed arterial vasculature of a patient-specific healthy and cirrhotic liver. An experimental feasibility study was performed to simulate the PD in a 3D-printed phantom of the cirrhotic arterial network.Results: Axial and in-plane injection locations were shown to be effective parameters to steer particles toward tumor tissue in both geometries. Increasing particle size or density made it more difficult for particles to exit the domain. As cancer burden increased, the catheter tip location mattered less. The in vitro study and numerical results confirmed that PD largely mimics flow distribution, but that significant differences are still possible.Conclusions: Our findings highlight that optimal parameter choice can lead to selective targeting of tumor tissue, but that targeting potential highly depends on patient-specific conditions.
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Affiliation(s)
- Tim Bomberna
- IBiTech-bioMMeda, Department of Electronics and Information Systems, Ghent University, Gent, Belgium.,Cancer Research Institute Ghent (CRIG), Ghent University, Gent, Belgium
| | - Ghazal Adeli Koudehi
- IBiTech-bioMMeda, Department of Electronics and Information Systems, Ghent University, Gent, Belgium
| | - Charlotte Claerebout
- IBiTech-bioMMeda, Department of Electronics and Information Systems, Ghent University, Gent, Belgium
| | - Chris Verslype
- Department of Clinical Digestive Oncology, University Hospitals Leuven and KU Leuven, Leuven, Belgium
| | - Geert Maleux
- Department of Radiology, University Hospitals Leuven, Leuven, Belgium.,Department of Imaging and Pathology, Leuven, Belgium
| | - Charlotte Debbaut
- IBiTech-bioMMeda, Department of Electronics and Information Systems, Ghent University, Gent, Belgium.,Cancer Research Institute Ghent (CRIG), Ghent University, Gent, Belgium
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13
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Kennedy P, Bane O, Hectors SJ, Fischman A, Schiano T, Lewis S, Taouli B. Noninvasive imaging assessment of portal hypertension. Abdom Radiol (NY) 2020; 45:3473-3495. [PMID: 32926209 PMCID: PMC10124623 DOI: 10.1007/s00261-020-02729-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 08/16/2020] [Accepted: 08/30/2020] [Indexed: 02/07/2023]
Abstract
Portal hypertension (PH) is a spectrum of complications of chronic liver disease (CLD) and cirrhosis, with manifestations including ascites, gastroesophageal varices, splenomegaly, hypersplenism, hepatic hydrothorax, hepatorenal syndrome, hepatopulmonary syndrome and portopulmonary hypertension. PH can vary in severity and is diagnosed via invasive hepatic venous pressure gradient measurement (HVPG), which is considered the reference standard. Accurate diagnosis of PH and assessment of severity are highly relevant as patients with clinically significant portal hypertension (CSPH) are at higher risk for developing acute variceal bleeding and mortality. In this review, we discuss current and upcoming noninvasive imaging methods for diagnosis and assessment of severity of PH.
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14
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Bane O, Said D, Weiss A, Stocker D, Kennedy P, Hectors SJ, Khaim R, Salem F, Delaney V, Menon MC, Markl M, Lewis S, Taouli B. 4D flow MRI for the assessment of renal transplant dysfunction: initial results. Eur Radiol 2020; 31:909-919. [PMID: 32870395 DOI: 10.1007/s00330-020-07208-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 07/07/2020] [Accepted: 08/19/2020] [Indexed: 12/26/2022]
Abstract
OBJECTIVES (1) Determine inter-observer reproducibility and test-retest repeatability of 4D flow parameters in renal allograft vessels; (2) determine if 4D flow measurements in the renal artery (RA) and renal vein (RV) can distinguish between functional and dysfunctional allografts; (3) correlate haemodynamic parameters with estimated glomerular filtration rate (eGFR), perfusion measured with dynamic contrast-enhanced MRI (DCE-MRI) and histopathology. METHODS Twenty-five prospectively recruited renal transplant patients (stable function/chronic renal allograft dysfunction, 12/13) underwent 4D flow MRI at 1.5 T. 4D flow coronal oblique acquisitions were performed in the transplant renal artery (RA) (velocity encoding parameter, VENC = 120 cm/s) and renal vein (RV) (VENC = 45 cm/s). Test-retest repeatability (n = 3) and inter-observer reproducibility (n = 10) were assessed by Cohen's kappa, coefficient of variation (CoV) and Bland-Altman statistics. Haemodynamic parameters were compared between patients and correlated to the estimated glomerular filtration rate, DCE-MRI parameters (n = 10) and histopathology from allograft biopsies (n = 15). RESULTS For inter-observer reproducibility, kappa was > 0.99 and 0.62 and CoV of flow was 12.6% and 7.8% for RA and RV, respectively. For test-retest repeatability, kappa was > 0.99 and 0.5 and CoV of flow was 27.3% and 59.4%, for RA and RV, respectively. RA (p = 0.039) and RV (p = 0.019) flow were both significantly reduced in dysfunctional allografts. Both identified chronic allograft dysfunction with good diagnostic performance (RA: AUC = 0.76, p = 0.036; RV: AUC = 0.8, p = 0.018). RA flow correlated negatively with histopathologic interstitial fibrosis score ci (ρ = - 0.6, p = 0.03). CONCLUSIONS 4D flow parameters had better repeatability in the RA than in the RV. RA and RV flow can identify chronic renal allograft dysfunction, with RA flow correlating with histopathologic interstitial fibrosis score. KEY POINTS • Inter-observer reproducibility of 4D flow measurements was acceptable in both the transplant renal artery and vein, but test-retest repeatability was better in the renal artery than in the renal vein. • Blood flow measurements obtained with 4D flow MRI in the renal artery and renal vein are significantly reduced in dysfunctional renal transplants. • Renal transplant artery flow correlated negatively with histopathologic interstitial fibrosis score.
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Affiliation(s)
- Octavia Bane
- Department of Radiology, Icahn School of Medicine at Mount Sinai (ISMMS), 1470 Madison Avenue, New York, NY, 10029, USA.,BioMedical Engineering and Imaging Institute, ISMMS, New York, NY, USA
| | - Daniela Said
- Department of Radiology, Icahn School of Medicine at Mount Sinai (ISMMS), 1470 Madison Avenue, New York, NY, 10029, USA.,BioMedical Engineering and Imaging Institute, ISMMS, New York, NY, USA
| | - Amanda Weiss
- Department of Radiology, Icahn School of Medicine at Mount Sinai (ISMMS), 1470 Madison Avenue, New York, NY, 10029, USA.,BioMedical Engineering and Imaging Institute, ISMMS, New York, NY, USA
| | - Daniel Stocker
- Department of Radiology, Icahn School of Medicine at Mount Sinai (ISMMS), 1470 Madison Avenue, New York, NY, 10029, USA.,BioMedical Engineering and Imaging Institute, ISMMS, New York, NY, USA
| | - Paul Kennedy
- Department of Radiology, Icahn School of Medicine at Mount Sinai (ISMMS), 1470 Madison Avenue, New York, NY, 10029, USA.,BioMedical Engineering and Imaging Institute, ISMMS, New York, NY, USA
| | - Stefanie J Hectors
- Department of Radiology, Icahn School of Medicine at Mount Sinai (ISMMS), 1470 Madison Avenue, New York, NY, 10029, USA.,BioMedical Engineering and Imaging Institute, ISMMS, New York, NY, USA.,Department of Radiology, Weill Cornell Medicine, New York, New York, NY, USA
| | - Rafael Khaim
- Division of Renal Medicine, Recanati Miller Transplantation Institute, ISMMS, New York, NY, USA
| | - Fadi Salem
- Department of Pathology, ISMMS, New York, NY, USA
| | - Veronica Delaney
- Division of Renal Medicine, Recanati Miller Transplantation Institute, ISMMS, New York, NY, USA
| | - Madhav C Menon
- Division of Renal Medicine, Recanati Miller Transplantation Institute, ISMMS, New York, NY, USA
| | - Michael Markl
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.,Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, USA
| | - Sara Lewis
- Department of Radiology, Icahn School of Medicine at Mount Sinai (ISMMS), 1470 Madison Avenue, New York, NY, 10029, USA.,BioMedical Engineering and Imaging Institute, ISMMS, New York, NY, USA
| | - Bachir Taouli
- Department of Radiology, Icahn School of Medicine at Mount Sinai (ISMMS), 1470 Madison Avenue, New York, NY, 10029, USA. .,BioMedical Engineering and Imaging Institute, ISMMS, New York, NY, USA.
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15
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Roncali E, Taebi A, Foster C, Vu CT. Personalized Dosimetry for Liver Cancer Y-90 Radioembolization Using Computational Fluid Dynamics and Monte Carlo Simulation. Ann Biomed Eng 2020; 48:1499-1510. [PMID: 32006268 PMCID: PMC7160004 DOI: 10.1007/s10439-020-02469-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Accepted: 01/25/2020] [Indexed: 12/14/2022]
Abstract
Yttrium-90 (Y-90) transarterial radioembolization uses radioactive microspheres injected into the hepatic artery to irradiate liver tumors internally. One of the major challenges is the lack of reliable dosimetry methods for dose prediction and dose verification. We present a patient-specific dosimetry approach for personalized treatment planning based on computational fluid dynamics (CFD) simulations of the microsphere transport combined with Y-90 physics modeling called CFDose. The ultimate goal is the development of a software to optimize the amount of activity and injection point for optimal tumor targeting. We present the proof-of-concept of a CFD dosimetry tool based on a patient's angiogram performed in standard-of-care planning. The hepatic arterial tree of the patient was segmented from the cone-beam CT (CBCT) to predict the microsphere transport using multiscale CFD modeling. To calculate the dose distribution, the predicted microsphere distribution was convolved with a Y-90 dose point kernel. Vessels as small as 0.45 mm were segmented, the microsphere distribution between the liver segments using flow analysis was predicted, the volumetric microsphere and resulting dose distribution in the liver volume were computed. The patient was imaged with positron emission tomography (PET) 2 h after radioembolization to evaluate the Y-90 distribution. The dose distribution was found to be consistent with the Y-90 PET images. These results demonstrate the feasibility of developing a complete framework for personalized Y-90 microsphere simulation and dosimetry using patient-specific input parameters.
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Affiliation(s)
- Emilie Roncali
- Department of Biomedical Engineering, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA.
| | - Amirtahà Taebi
- Department of Biomedical Engineering, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Cameron Foster
- Department of Radiology, UC Davis Medical Center, Sacramento, CA, 95817, USA
| | - Catherine Tram Vu
- Department of Radiology, UC Davis Medical Center, Sacramento, CA, 95817, USA
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16
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Blood flow of the venous system during resuscitative endovascular balloon occlusion of the aorta: Noninvasive evaluation using phase contrast magnetic resonance imaging. J Trauma Acute Care Surg 2020; 88:305-309. [PMID: 31804421 DOI: 10.1097/ta.0000000000002557] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a viable resuscitation approach for a subdiaphragmatic injury that can regulate arterial blood flow. On the other hand, the evaluation of venous or portal venous blood flow during REBOA remains insufficient because invasive cannulation or exposure of the vessel may affect the blood flow, and Doppler echography is highly operator-dependent. However, phase contrast magnetic resonance imaging has enabled accurate evaluation and noninvasive measurement. This study aimed to investigate the change of venous and portal venous blood flow during REBOA in a porcine model. METHODS Seven pigs were anesthetized, and a REBOA catheter was placed. The blood flows of the inferior vena cava (IVC), hepatic vein (HV), portal vein (PV), and superior vena cava (SVC) were measured using phase contrast magnetic resonance imaging, in both the balloon deflated (no-REBOA) and fully balloon inflated (REBOA) states. Mean arterial pressure (MAP), central venous pressure, cardiac index, and systemic vascular resistance index were measured. RESULTS The blood flows of the suprahepatic, infrahepatic, and distal IVC, HV, and PV in the no-REBOA state were 1.40 ± 0.36 L·min, 0.94 ± 0.16 L·min, 0.50 ± 0.19 L·min, 0.060 ± 0.018 L·min, and 0.32 ± 0.091 L·min, respectively. The blood flow of each section in the REBOA condition was significantly decreased at 0.41 ± 0.078 (33% of baseline), 0.15 ± 0.13 (15%), 0.043 ± 0.034 (9%), 0.029 ± 0.017 (37%), and 0.070 ± 0.034 L·min (21%), respectively. The blood flow of the SVC increased significantly in the REBOA condition (1.4 ± 0.63 L·min vs. 0.53 ± 0.14 L·min [257%]). Mean arterial pressure, central venous pressure, cardiac index, and systemic vascular resistance index were significantly increased after REBOA inflation. CONCLUSION Resuscitative endovascular balloon occlusion of the aorta decreased blood flows of the IVC, HV, and PV and increased blood flow of the SVC. This result could be explained by the collateral flow from the lower body to the SVC. A better understanding of the effect of REBOA on the venous and portal venous systems may help control liver injury.
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17
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Park J, Kim J, Chang Y, Youn SW, Lee HJ, Kang EJ, Lee KN, Suchánek V, Hyun S, Lee J. Analysis of the time-velocity curve in phase-contrast magnetic resonance imaging: a phantom study. Comput Assist Surg (Abingdon) 2019; 24:3-12. [PMID: 31385716 DOI: 10.1080/24699322.2019.1649066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
The aim of this study was to analyze the characteristics of time-velocity curve acquired by phase-contrast magnetic resonance imaging (PC-MRI) using an in-vitro flow model as a reference for hemodynamic studies. The time- velocity curves of the PC-MRI were compared with Doppler ultrasonography (US) and also compared with those obtained in the electromagnetic flowmeter. The correlation between techniques was analyzed using an electromagnetic flowmeter as a reference standard; the maximum, minimum, and average velocities, full-width at half-maximum (FWHM), and ascending gradient (AG) were measured from time-velocity curves. The correlations between an electromagnetic flowmeter and the respective measurement technique for the PC-MRI and Doppler US were found to be high (mean R2 > 0.9, p < 0.05). These results indicate that these measurement techniques are useful for measuring blood flow information and reflect actual flow. The PC-MRI was the best fit for the minimum velocity and FWHM, and the maximum velocity and AG were the best fit for Doppler US. The PC-MRI showed lower maximum velocity value and higher minimum velocity value than Doppler US. Therefore, PC-MRI demonstrates more obtuse time-velocity curve than Doppler US. In addition, the time- velocity curve of PC-MRI could be calibrated by introducing formulae that can convert each measurement value to a reference standard value within a 10% error. The PC-MRI can be used to estimate the Doppler US using this formula.
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Affiliation(s)
- Jieun Park
- Department of Biomedical Engineering, Kyungpook National University , Daegu , Republic of Korea
| | - Junghun Kim
- Department of Biomedical Engineering, Kyungpook National University , Daegu , Republic of Korea
| | - Yongmin Chang
- Department of Radiology, Kyungpook National University & Hospital , Daegu , Republic of Korea
| | - Sung Won Youn
- Department of Radiology, Catholic University of Daegu Medical Center , Daegu , Republic of Korea
| | - Hui Joong Lee
- Department of Radiology, Kyungpook National University & Hospital , Daegu , Republic of Korea
| | - Eun-Ju Kang
- Department of Radiology, Dong-A University College of Medicine , Busan , Republic of Korea
| | - Ki-Nam Lee
- Department of Radiology, Dong-A University College of Medicine , Busan , Republic of Korea
| | - Vojtěch Suchánek
- Department of Radiology, Kyungpook National University & Hospital , Daegu , Republic of Korea
| | - Sinjae Hyun
- Department of Biomedical Engineering, Mercer University , Macon , GA , USA
| | - Jongmin Lee
- Department of Radiology, Kyungpook National University & Hospital , Daegu , Republic of Korea
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18
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Valliant EM, Filiaggi MJ. Impact of trivalent ions on the stability and cohesion of calcium polyphosphate coacervates for embolization applications. J Biomed Mater Res B Appl Biomater 2019; 107:2638-2648. [PMID: 30860666 DOI: 10.1002/jbm.b.34353] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 02/17/2019] [Accepted: 02/18/2019] [Indexed: 11/06/2022]
Abstract
Polyphosphates (PPs) are of interest as temporary in situ setting embolic agents for which cohesive characteristics are vital. Trivalent ions Al3+ and Ga3+ were substituted into calcium PP up to 10 mol % for two PP chain lengths (degree of polymerization, Dp 200 and 9000) and the effect on the dissolution rate of the resulting coacervate was examined. High levels of trivalent ions were found to increase the dissolution rate, especially with aluminum (Al) where the coacervate with the greatest Al content (10 mol %) and larger Dp completely dissolved within the first few hours in tris(hydroxymethyl)aminomethane buffered saline. Conversely, small amounts of trivalent ions slowed the dissolution rate of the coacervates compared to those containing calcium only. The coacervate compositions determined to have the fastest and slowest ion release were evaluated for cohesion upon injection into a simulated blood vessel using a dual lumen needle. PPs with lower trivalent content had a higher coacervate yield overall, with 5% Ga and Dp 200 yielding the smallest proportion of coacervate particulates that could be implicated in unwanted distal embolization. However, further studies are required to evaluate the formation and duration of occlusions in vivo so that the PP composition can best be tailored to meet clinical requirements. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B:2638-2648, 2019.
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Affiliation(s)
- Esther Mae Valliant
- School of Biomedical Engineering, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Mark Joseph Filiaggi
- School of Biomedical Engineering, Dalhousie University, Halifax, Nova Scotia, Canada.,Department of Applied Oral Sciences, Faculty of Dentistry, Dalhousie University, Halifax, Nova Scotia, Canada
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19
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Kadoya Y, Miyati T, Kobayashi S, Ohno N, Gabata T. Effect of gravity on portal venous flow: Evaluation using multiposture MRI. J Magn Reson Imaging 2019; 50:83-87. [PMID: 30618102 DOI: 10.1002/jmri.26626] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 12/06/2018] [Accepted: 12/08/2018] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Analysis of portal venous flow (PVF) is important when evaluating the severity and prognosis of liver disease. PVF might be altered by postural changes (ie, difference in the effects of gravity). PURPOSE To evaluate the effect of gravity on PVF using a novel MRI system, which can obtain abdominal MRIs in both the supine and the upright positions. STUDY TYPE Prospective self control. SUBJECTS Twelve healthy young male volunteers. FIELD STRENGTH/SEQUENCE Caval velocity-mapped images were obtained using the electrocardiography-triggered cine phase-contrast technique in the supine and upright positions with multiposture MRI (paired 0.4 T permanent magnets). ASSESSMENT The mean PVF velocity in the region of interest in each cardiac phase was determined. A PVF curve in the cardiac cycle was also obtained from the PVF velocity multiplied by the cross-sectional area. The mean PVF velocity, maximum PVF velocity, cross-sectional area of the PV, mean PVF, maximum PVF, and heart rate in the supine and upright positions were assessed. STATISTICAL TESTS Wilcoxon signed-rank tests were applied. P < 0.05 was considered statistically significant. RESULTS The mean PVF velocity, maximum PVF velocity, cross-sectional area of the PV, mean PVF, and maximum PVF were all significantly lower in the upright position compared with the supine position (P = 0.002 for all), with differences of 42% ± 15%, 38% ± 12%, 60% ± 17%, 24% ± 11%, and 22% ± 9.3%, respectively. However, heart rate was significantly higher (116% ± 9.2%, P = 0.003) in the upright position compared with the supine position. DATA CONCLUSION The effect of gravity during postural change from a supine to an upright position significantly decreases the PVF. Multiposture MRI allows acquisition of more detailed information on liver function. LEVEL OF EVIDENCE 2 Technical Efficacy Stage: 1 J. Magn. Reson. Imaging 2019;50:83-87.
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Affiliation(s)
- Yoshisuke Kadoya
- Department of Radiology, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Japan
| | - Tosiaki Miyati
- Department of Quantum Medical Imaging, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Japan
| | - Satoshi Kobayashi
- Department of Radiology, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Japan.,Department of Quantum Medical Imaging, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Japan
| | - Naoki Ohno
- Department of Quantum Medical Imaging, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Japan
| | - Toshifumi Gabata
- Department of Radiology, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Japan
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20
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Bekheit M, Audebert C, Bucur P, Adriaensen H, Bled E, Wartenberg M, Vignon-Clementel I, Vibert E. Transit time ultrasound perivascular flow probe technology is superior to MR imaging on hepatic blood flow measurement in a porcine model. Hepatobiliary Pancreat Dis Int 2018; 17:538-545. [PMID: 30170983 DOI: 10.1016/j.hbpd.2018.07.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Accepted: 07/10/2018] [Indexed: 02/08/2023]
Abstract
BACKGROUND The hepatic hemodynamics is an essential parameter in surgical planning as well as in various disease processes. The transit time ultrasound (TTUS) perivascular flow probe technology is widely used in clinical practice to evaluate the hepatic inflow, yet invasive. The phase-contrast-MRI (PC-MRI) is not invasive and potentially applicable in assessing the hepatic blood flow. In the present study, we compared the hepatic inflow rates using the PC-MRI and the TTUS probe, and evaluated their predictive value of post-hepatectomy adverse events. METHODS Eighteen large white pigs were anaesthetized for PC-MRI and approximately 75% hepatic resection was performed under a unified protocol. The blood flow was measured in the hepatic artery (Qha), the portal vein (Qpv), and the aorta above the celiac trunk (Qca) using PC-MRI, and was compared to the TTUS probe. The Bland-Altman method was conducted and a partial least squares regression (PLS) model was implemented. RESULTS The mean Qpv measured in PC-MRI was 0.55 ± 0.12 L/min, and in the TTUS probe was 0.74 ± 0.17 L/min. Qca was 1.40 ± 0.47 L/min in the PC-MRI and 2.00 ± 0.60 L/min in the TTUS probe. Qha was 0.17 ± 0.10 L/min in the PC-MRI, and 0.13 ± 0.06 L/min in the TTUS probe. The Bland-Altman method revealed that the estimated bias of Qca in the PC-MRI was 32% (95% CI: -49% to 15%); Qha 17% (95% CI: -15% to 51%); and Qpv 40% (95% CI: -62% to 18%). The TTUS probe had a higher weight in predicting adverse outcomes after 75% resection compared to the PC-MRI (β= 0.35 and 0.43 vs β = 0.22 and 0.07, for tissue changes and premature death, respectively). CONCLUSIONS There is a tendency of the PC-MRI to underestimate the flow measured by the TTUS probes. The TTUS probe measures are more predictive of relevant post-hepatectomy outcomes.
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Affiliation(s)
- Mohamed Bekheit
- Inserm Unité 1193, 112 Boulevard Paul Valliant Cuturier, Villejuif, France; Institute of medical sciences, University of Aberdeen, Aberdeen, UK
| | - Chloe Audebert
- Centre de recherche Inria de Paris, Paris, France; Sorbonne Universités, UPMC University of Paris 6, Laboratoire Jacques-Louis, Lions, Paris, France
| | - Petru Bucur
- Inserm Unité 1193, 112 Boulevard Paul Valliant Cuturier, Villejuif, France; CHRU, hôpitaux de Tours, Chirurgie Hépato-biliaire et Pancréatique, Transplantation Hépatique, Tours, France
| | - Hans Adriaensen
- Plateforme Chirurgie et Imagerie pour le Recherche et l'Enseignement (CIRE), Imagerie, UMR-PRC, 37380 Nouzilly, Centre INRA Val de Loire, France
| | - Emilie Bled
- Plateforme Chirurgie et Imagerie pour le Recherche et l'Enseignement (CIRE), Imagerie, UMR-PRC, 37380 Nouzilly, Centre INRA Val de Loire, France
| | | | - Irene Vignon-Clementel
- Centre de recherche Inria de Paris, Paris, France; Sorbonne Universités, UPMC University of Paris 6, Laboratoire Jacques-Louis, Lions, Paris, France
| | - Eric Vibert
- Inserm Unité 1193, 112 Boulevard Paul Valliant Cuturier, Villejuif, France; AP-HP, Hôpital Paul Brousse, Centre Hépato-Biliaire, Villejuif, France.
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21
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Bradley CR, Cox EF, Scott RA, James MW, Kaye P, Aithal GP, Francis ST, Guha IN. Multi-organ assessment of compensated cirrhosis patients using quantitative magnetic resonance imaging. J Hepatol 2018; 69:1015-1024. [PMID: 29886155 DOI: 10.1016/j.jhep.2018.05.037] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 05/29/2018] [Accepted: 05/30/2018] [Indexed: 12/17/2022]
Abstract
BACKGROUND & AIMS Advancing liver disease results in deleterious changes in a number of critical organs. The ability to measure structure, blood flow and tissue perfusion within multiple organs in a single scan has implications for determining the balance of benefit vs. harm for therapies. Our aim was to establish the feasibility of magnetic resonance imaging (MRI) to assess changes in Compensated Cirrhosis (CC), and relate this to disease severity and future liver-related outcomes (LROs). METHODS A total of 60 patients with CC, 40 healthy volunteers and 7 patients with decompensated cirrhosis were recruited. In a single scan session, MRI measures comprised phase-contrast MRI vessel blood flow, arterial spin labelling tissue perfusion, T1 longitudinal relaxation time, heart rate, cardiac index, and volume assessment of the liver, spleen and kidneys. We explored the association between MRI parameters and disease severity, analysing differences in baseline MRI parameters in the 11 (18%) patients with CC who experienced future LROs. RESULTS In the liver, compositional changes were reflected by increased T1 in progressive disease (p <0.001) and an increase in liver volume in CC (p = 0.006), with associated progressive reduction in liver (p <0.001) and splenic (p <0.001) perfusion. A significant reduction in renal cortex T1 and increase in cardiac index and superior mesenteric arterial blood flow was seen with increasing disease severity. Baseline liver T1 (p = 0.01), liver perfusion (p <0.01), and renal cortex T1 (p <0.01) were significantly different in patients with CC who subsequently developed negative LROs. CONCLUSIONS MRI enables the contemporaneous assessment of organs in liver cirrhosis in a single scan without the requirement for a contrast agent. MRI parameters of liver T1, renal T1, hepatic and splenic perfusion, and superior mesenteric arterial blood flow were related to the risk of LROs. LAY SUMMARY This study assesses the changes to structure, blood flow and perfusion that occur in the key organs (liver, spleen and kidney) associated with severe liver disease (Compensated Cirrhosis), using magnetic resonance imaging. The magnetic resonance imaging measures which changed with disease severity and were related to negative liver-related clinical outcomes are described.
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Affiliation(s)
- Christopher R Bradley
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK; NIHR Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK
| | - Eleanor F Cox
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK; NIHR Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK
| | - Robert A Scott
- NIHR Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK
| | - Martin W James
- NIHR Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK
| | - Phillip Kaye
- NIHR Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK
| | - Guruprasad P Aithal
- NIHR Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK; Nottingham Digestive Diseases Centre, School of Medicine, University of Nottingham, Nottingham, UK
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK; NIHR Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK
| | - Indra Neil Guha
- NIHR Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK; Nottingham Digestive Diseases Centre, School of Medicine, University of Nottingham, Nottingham, UK.
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22
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Bane O, Peti S, Wagner M, Hectors S, Dyvorne H, Markl M, Taouli B. Hemodynamic measurements with an abdominal 4D flow MRI sequence with spiral sampling and compressed sensing in patients with chronic liver disease. J Magn Reson Imaging 2018; 49:994-1005. [PMID: 30318674 DOI: 10.1002/jmri.26305] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 07/30/2018] [Accepted: 07/31/2018] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND The test-retest/interobserver repeatability and diagnostic value of 4D flow MRI in liver disease is underreported. PURPOSE To determine the reproducibility/repeatability of flow quantification in abdominal vessels using a spiral 4D flow MRI sequence; to assess the value of 4D flow parameters in diagnosing cirrhosis and degree of portal hypertension. STUDY TYPE Prospective. SUBJECTS Fifty-two patients with chronic liver disease. FIELD STRENGTH/SEQUENCE 1.5T/spiral 4D flow acquired in one breath-hold. ASSESSMENT Thirteen abdominal vessels were identified and segmented by two independent observers to measure maximum and time-averaged through-plane velocity, net flow, and vessel cross-section area. Interobserver agreement and test-retest repeatability were evaluated in 15 and 4 cases, respectively. Prediction of the presence and severity of cirrhosis and portal hypertension was assessed using 4D flow parameters. STATISTICAL TESTS Cohen's kappa coefficient, coefficient of variation (CV), Bland-Altman, Mann-Whitney tests, logistic regression. RESULTS For all vessels combined, measurements showed acceptable agreement between observers, with Cohen's kappa = 0.70 (P < 0.001), CV < 21%, Bland-Altman bias <5%, but high limits of agreement ([-75%,75%]). Test-retest repeatability was excellent in large vessels (CV = 1-15%, bias = 1-25%, Bland-Altman limits of agreement [BALA] = [4%,150%]), and poor in small vessels (CV = 7-130%, bias = 10-200%, BALA = [8%,190%]). Average velocity in the right hepatic vein and average area of the splenic vein were higher in cirrhosis (P = 0.027/0.0039). Flow in the middle hepatic vein strongly correlated with Child-Pugh score (ρ = 0.84, P = 0.0238), while flow in the splenic vein (ρ = 0.43, P = 0.032), time-average (ρ = 0.46, P = 0.02) and peak velocity in the superior mesenteric vein (ρ = 0.45, P = 0.032), and peak velocity in the infrarenal IVC (ρ = 0.39, P = 0.032) positively correlated with an imaging-based portal hypertension score. Average area of the splenic vein predicted cirrhosis (P = 0.019; area under the curve AUC [95% confidence interval, CI] = 0.87 [0.71,1.00]) and clinically significant portal hypertension (P = 0.042; AUC [95% CI] = 0.78 [0.57-0.99]). DATA CONCLUSION Spiral 4D flow allows comprehensive assessment of abdominal vessels in one breath-hold, with substantial interobserver reproducibility, but variable test-retest repeatability. 4D flow may potentially reflect vascular changes due to cirrhosis and portal hypertension. LEVEL OF EVIDENCE 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:994-1005.
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Affiliation(s)
- Octavia Bane
- Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA.,Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Steven Peti
- Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Mathilde Wagner
- Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA.,Department of Radiology, Groupe Hospitalier Pitié Salpêtrière, Paris, France
| | - Stefanie Hectors
- Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA.,Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Hadrien Dyvorne
- Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA.,Catalyzer, Guilford, Connecticut, USA
| | - Michael Markl
- Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.,Department of Biomedical Engineering, Northwestern University, Evanston, Illinois, USA
| | - Bachir Taouli
- Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA.,Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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23
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Cox EF, Palaniyappan N, Aithal GP, Guha IN, Francis ST. MRI assessment of altered dynamic changes in liver haemodynamics following a meal challenge in compensated cirrhosis. Eur Radiol Exp 2018. [PMCID: PMC6156698 DOI: 10.1186/s41747-018-0056-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Del Chicca F, Schwarz A, Grest P, Willmitzer F, Dennler M, Kircher PR. Cardiac-gated, phase contrast magnetic resonance angiography is a reliable and reproducible technique for quantifying blood flow in canine major cranial abdominal vessels. Vet Radiol Ultrasound 2018; 59:423-431. [PMID: 29667282 DOI: 10.1111/vru.12615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 11/23/2017] [Accepted: 01/17/2018] [Indexed: 11/29/2022] Open
Abstract
Blood flow changes in cranial abdominal vessels are important contributing factors for canine hepatic disease. This prospective, experimental, pilot study aimed to evaluate cardiac-gated, phase contrast magnetic resonance angiography (PCMRA) as a method for characterizing blood flow in canine major cranial abdominal vessels. Eleven, healthy, adult beagle dogs were sampled. Cardiac-gated, phase contrast magnetic resonance angiography of the cranial abdomen was performed in each dog and blood flow was independently measured in each of the major cranial abdominal vessels by three observers, with two observers recording blood flow values once and one observer recording blood flow values three times. Each dog then underwent ultrasonographic examination of the liver with fine needle aspirations and biopsies submitted to cytologic and histologic examination. The mean absolute stroke volume and velocity were respectively 9.6 ± 1.9 ml and -11.1 ± 1.1 cm/s for the cranial abdominal aorta, 2.1 ± 0.6 ml and -6.6 ± 1.9 cm/s for the celiac artery, and 2.3 ± 1.0 ml and -7.9 ± 3.1 cm/s for the cranial mesenteric artery. The mean absolute stroke volume and velocity were respectively 6.7 ± 1.3 ml and 3.9 ± 0.9 cm/s for the caudal vena cava and 2.6 ± 0.9 ml and 3.2 ± 1.2 cm/s for the portal vein. Intraobserver reliability was excellent (intraclass correlation coefficient > 0.9). Interobserver reproducibility was also excellent (intraclass correlation coefficient 0.89-0.99). Results of liver ultrasonography, cytology, and histopathology were unremarkable. Findings indicated that cardiac-gated, phase contrast magnetic resonance angiography is a feasible technique for quantifying blood blow in canine major cranial abdominal vessels. Blood flow values from this sample of healthy beagles can be used as background for future studies on canine hepatic disease.
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Affiliation(s)
- Francesca Del Chicca
- Clinic of Diagnostic Imaging, Vetsuisse Faculty University of Zurich, Zurich, 8057, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, 3012, Switzerland
| | - Andrea Schwarz
- Section of Anaesthesiology, Equine Department, Vetsuisse Faculty University of Zurich, Zurich, 8057, Switzerland
| | - Paula Grest
- Institute of Veterinary Pathology, Vetsuisse Faculty University of Zurich, Zurich, 8057, Switzerland
| | - Florian Willmitzer
- Clinic of Diagnostic Imaging, Vetsuisse Faculty University of Zurich, Zurich, 8057, Switzerland
| | - Matthias Dennler
- Clinic of Diagnostic Imaging, Vetsuisse Faculty University of Zurich, Zurich, 8057, Switzerland
| | - Patrick R Kircher
- Clinic of Diagnostic Imaging, Vetsuisse Faculty University of Zurich, Zurich, 8057, Switzerland
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25
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Muthusami P, Yoo SJ, Chaturvedi R, Gill N, Windram J, Schantz D, Prsa M, Caro-Dominguez P, Seed M, Grosse-Wortmann L, Ling SC, Chavhan GB. Splanchnic, Thoracoabdominal, and Cerebral Blood Flow Volumes in Healthy Children and Young Adults in Fasting and Postprandial States: Determining Reference Ranges by Using Phase-Contrast MR Imaging. Radiology 2017; 285:231-241. [DOI: 10.1148/radiol.2017162114] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Prakash Muthusami
- From the Department of Diagnostic Imaging (P.M., S.J.Y., N.T., J.W., D.S., M.P., P.C.D., M.S., L.G.W., G.B.C.), Division of Cardiology, Department of Pediatrics (S.J.Y., R.C., J.W., D.S., M.P., M.S., L.G.W.), and Division of Gastroenterology, Hepatology, and Nutrition (S.C.L.), the Hospital For Sick Children, 555 University Ave, Toronto, ON, Canada M5G 1X8; and Departments of Medical Imaging (P.M., S.J.Y., P.C.D., M.S., L.G.W., G.B.C.), and Pediatrics (R.C., S.C.L.), University of Toronto, Toronto, Canada
| | - Shi-Joon Yoo
- From the Department of Diagnostic Imaging (P.M., S.J.Y., N.T., J.W., D.S., M.P., P.C.D., M.S., L.G.W., G.B.C.), Division of Cardiology, Department of Pediatrics (S.J.Y., R.C., J.W., D.S., M.P., M.S., L.G.W.), and Division of Gastroenterology, Hepatology, and Nutrition (S.C.L.), the Hospital For Sick Children, 555 University Ave, Toronto, ON, Canada M5G 1X8; and Departments of Medical Imaging (P.M., S.J.Y., P.C.D., M.S., L.G.W., G.B.C.), and Pediatrics (R.C., S.C.L.), University of Toronto, Toronto, Canada
| | - Rajiv Chaturvedi
- From the Department of Diagnostic Imaging (P.M., S.J.Y., N.T., J.W., D.S., M.P., P.C.D., M.S., L.G.W., G.B.C.), Division of Cardiology, Department of Pediatrics (S.J.Y., R.C., J.W., D.S., M.P., M.S., L.G.W.), and Division of Gastroenterology, Hepatology, and Nutrition (S.C.L.), the Hospital For Sick Children, 555 University Ave, Toronto, ON, Canada M5G 1X8; and Departments of Medical Imaging (P.M., S.J.Y., P.C.D., M.S., L.G.W., G.B.C.), and Pediatrics (R.C., S.C.L.), University of Toronto, Toronto, Canada
| | - Navjot Gill
- From the Department of Diagnostic Imaging (P.M., S.J.Y., N.T., J.W., D.S., M.P., P.C.D., M.S., L.G.W., G.B.C.), Division of Cardiology, Department of Pediatrics (S.J.Y., R.C., J.W., D.S., M.P., M.S., L.G.W.), and Division of Gastroenterology, Hepatology, and Nutrition (S.C.L.), the Hospital For Sick Children, 555 University Ave, Toronto, ON, Canada M5G 1X8; and Departments of Medical Imaging (P.M., S.J.Y., P.C.D., M.S., L.G.W., G.B.C.), and Pediatrics (R.C., S.C.L.), University of Toronto, Toronto, Canada
| | - Jonathan Windram
- From the Department of Diagnostic Imaging (P.M., S.J.Y., N.T., J.W., D.S., M.P., P.C.D., M.S., L.G.W., G.B.C.), Division of Cardiology, Department of Pediatrics (S.J.Y., R.C., J.W., D.S., M.P., M.S., L.G.W.), and Division of Gastroenterology, Hepatology, and Nutrition (S.C.L.), the Hospital For Sick Children, 555 University Ave, Toronto, ON, Canada M5G 1X8; and Departments of Medical Imaging (P.M., S.J.Y., P.C.D., M.S., L.G.W., G.B.C.), and Pediatrics (R.C., S.C.L.), University of Toronto, Toronto, Canada
| | - Daryl Schantz
- From the Department of Diagnostic Imaging (P.M., S.J.Y., N.T., J.W., D.S., M.P., P.C.D., M.S., L.G.W., G.B.C.), Division of Cardiology, Department of Pediatrics (S.J.Y., R.C., J.W., D.S., M.P., M.S., L.G.W.), and Division of Gastroenterology, Hepatology, and Nutrition (S.C.L.), the Hospital For Sick Children, 555 University Ave, Toronto, ON, Canada M5G 1X8; and Departments of Medical Imaging (P.M., S.J.Y., P.C.D., M.S., L.G.W., G.B.C.), and Pediatrics (R.C., S.C.L.), University of Toronto, Toronto, Canada
| | - Milan Prsa
- From the Department of Diagnostic Imaging (P.M., S.J.Y., N.T., J.W., D.S., M.P., P.C.D., M.S., L.G.W., G.B.C.), Division of Cardiology, Department of Pediatrics (S.J.Y., R.C., J.W., D.S., M.P., M.S., L.G.W.), and Division of Gastroenterology, Hepatology, and Nutrition (S.C.L.), the Hospital For Sick Children, 555 University Ave, Toronto, ON, Canada M5G 1X8; and Departments of Medical Imaging (P.M., S.J.Y., P.C.D., M.S., L.G.W., G.B.C.), and Pediatrics (R.C., S.C.L.), University of Toronto, Toronto, Canada
| | - Pablo Caro-Dominguez
- From the Department of Diagnostic Imaging (P.M., S.J.Y., N.T., J.W., D.S., M.P., P.C.D., M.S., L.G.W., G.B.C.), Division of Cardiology, Department of Pediatrics (S.J.Y., R.C., J.W., D.S., M.P., M.S., L.G.W.), and Division of Gastroenterology, Hepatology, and Nutrition (S.C.L.), the Hospital For Sick Children, 555 University Ave, Toronto, ON, Canada M5G 1X8; and Departments of Medical Imaging (P.M., S.J.Y., P.C.D., M.S., L.G.W., G.B.C.), and Pediatrics (R.C., S.C.L.), University of Toronto, Toronto, Canada
| | - Mike Seed
- From the Department of Diagnostic Imaging (P.M., S.J.Y., N.T., J.W., D.S., M.P., P.C.D., M.S., L.G.W., G.B.C.), Division of Cardiology, Department of Pediatrics (S.J.Y., R.C., J.W., D.S., M.P., M.S., L.G.W.), and Division of Gastroenterology, Hepatology, and Nutrition (S.C.L.), the Hospital For Sick Children, 555 University Ave, Toronto, ON, Canada M5G 1X8; and Departments of Medical Imaging (P.M., S.J.Y., P.C.D., M.S., L.G.W., G.B.C.), and Pediatrics (R.C., S.C.L.), University of Toronto, Toronto, Canada
| | - Lars Grosse-Wortmann
- From the Department of Diagnostic Imaging (P.M., S.J.Y., N.T., J.W., D.S., M.P., P.C.D., M.S., L.G.W., G.B.C.), Division of Cardiology, Department of Pediatrics (S.J.Y., R.C., J.W., D.S., M.P., M.S., L.G.W.), and Division of Gastroenterology, Hepatology, and Nutrition (S.C.L.), the Hospital For Sick Children, 555 University Ave, Toronto, ON, Canada M5G 1X8; and Departments of Medical Imaging (P.M., S.J.Y., P.C.D., M.S., L.G.W., G.B.C.), and Pediatrics (R.C., S.C.L.), University of Toronto, Toronto, Canada
| | - Simon C. Ling
- From the Department of Diagnostic Imaging (P.M., S.J.Y., N.T., J.W., D.S., M.P., P.C.D., M.S., L.G.W., G.B.C.), Division of Cardiology, Department of Pediatrics (S.J.Y., R.C., J.W., D.S., M.P., M.S., L.G.W.), and Division of Gastroenterology, Hepatology, and Nutrition (S.C.L.), the Hospital For Sick Children, 555 University Ave, Toronto, ON, Canada M5G 1X8; and Departments of Medical Imaging (P.M., S.J.Y., P.C.D., M.S., L.G.W., G.B.C.), and Pediatrics (R.C., S.C.L.), University of Toronto, Toronto, Canada
| | - Govind B. Chavhan
- From the Department of Diagnostic Imaging (P.M., S.J.Y., N.T., J.W., D.S., M.P., P.C.D., M.S., L.G.W., G.B.C.), Division of Cardiology, Department of Pediatrics (S.J.Y., R.C., J.W., D.S., M.P., M.S., L.G.W.), and Division of Gastroenterology, Hepatology, and Nutrition (S.C.L.), the Hospital For Sick Children, 555 University Ave, Toronto, ON, Canada M5G 1X8; and Departments of Medical Imaging (P.M., S.J.Y., P.C.D., M.S., L.G.W., G.B.C.), and Pediatrics (R.C., S.C.L.), University of Toronto, Toronto, Canada
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Assessment of Haemodynamic Response to Nonselective Beta-Blockers in Portal Hypertension by Phase-Contrast Magnetic Resonance Angiography. BIOMED RESEARCH INTERNATIONAL 2017; 2017:9281450. [PMID: 28698881 PMCID: PMC5494094 DOI: 10.1155/2017/9281450] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 04/08/2017] [Accepted: 05/04/2017] [Indexed: 02/07/2023]
Abstract
A significant unmet need exists for accurate, reproducible, noninvasive diagnostic tools to assess and monitor portal hypertension (PHT). We report the first use of quantitative MRI markers for the haemodynamic assessment of nonselective beta-blockers (NSBB) in PHT. In a randomized parallel feasibility study in 22 adult patients with PHT and a clinical indication for NSBB, we acquired haemodynamic data at baseline and after 4 weeks of NSBB (propranolol or carvedilol) using phase-contrast MR angiography (PC-MRA) in selected intra-abdominal vessels. T1 mapping of liver and spleen was undertaken to assess changes in tissue composition. Target NSBB dose was achieved in 82%. There was a substantial reduction from baseline in mean average flow in the superior abdominal aorta after 4 weeks of NSBB therapy (4.49 ± 0.98 versus 3.82 ± 0.86 L/min, P = 0.03) but there were no statistically significant differences in flow in any other vessels, even in patients with >25% decrease in heart rate (47% of patients). Mean percentage change in liver and spleen T1 following NSBB was small and highly variable. In conclusion, PC-MRA was able to detect reduction in cardiac output by NSBB but did not detect significant changes in visceral blood flow or T1. This trial was registered with the ISRCTN registry (ISRCTN98001632).
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Geometric modeling of hepatic arteries in 3D ultrasound with unsupervised MRA fusion during liver interventions. Int J Comput Assist Radiol Surg 2017; 12:961-972. [PMID: 28271356 DOI: 10.1007/s11548-017-1550-4] [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: 01/28/2017] [Accepted: 02/27/2017] [Indexed: 10/20/2022]
Abstract
PURPOSE Modulating the chemotherapy injection rate with regard to blood flow velocities in the tumor-feeding arteries during intra-arterial therapies may help improve liver tumor targeting while decreasing systemic exposure. These velocities can be obtained noninvasively using Doppler ultrasound (US). However, small vessels situated in the liver are difficult to identify and follow in US. We propose a multimodal fusion approach that non-rigidly registers a 3D geometric mesh model of the hepatic arteries obtained from preoperative MR angiography (MRA) acquisitions with intra-operative 3D US imaging. METHODS The proposed fusion tool integrates 3 imaging modalities: an arterial MRA, a portal phase MRA and an intra-operative 3D US. Preoperatively, the arterial phase MRA is used to generate a 3D model of the hepatic arteries, which is then non-rigidly co-registered with the portal phase MRA. Once the intra-operative 3D US is acquired, we register it with the portal MRA using a vessel-based rigid initialization followed by a non-rigid registration using an image-based metric based on linear correlation of linear combination. Using the combined non-rigid transformation matrices, the 3D mesh model is fused with the 3D US. RESULTS 3D US and multi-phase MRA images acquired from 10 porcine models were used to test the performance of the proposed fusion tool. Unimodal registration of the MRA phases yielded a target registration error (TRE) of [Formula: see text] mm. Initial rigid alignment of the portal MRA and 3D US yielded a mean TRE of [Formula: see text] mm, which was significantly reduced to [Formula: see text] mm ([Formula: see text]) after affine image-based registration. The following deformable registration step allowed for further decrease of the mean TRE to [Formula: see text] mm. CONCLUSION The proposed tool could facilitate visualization and localization of these vessels when using 3D US intra-operatively for either intravascular or percutaneous interventions to avoid vessel perforation.
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Schaffner D, von Elverfeldt D, Deibert P, Lazaro A, Merfort I, Lutz L, Neubauer J, Baumstark MW, Kreisel W, Reichardt W. Phase-contrast MR flow imaging: A tool to determine hepatic hemodynamics in rats with a healthy, fibrotic, or cirrhotic liver. J Magn Reson Imaging 2017; 46:1526-1534. [PMID: 28240794 DOI: 10.1002/jmri.25677] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 02/01/2017] [Indexed: 12/14/2022] Open
Abstract
PURPOSE To test a magnetic resonance (MR) scanning protocol as a noninvasive tool to determine hepatic hemodynamics and to assess the degree of liver fibrosis in an animal model of liver fibrosis and cirrhosis. MATERIALS AND METHODS Fifty-four male Wistar rats were studied. Thirty-nine received thioacetamide (TAA) in their drinking water for either 12 or 16 weeks. MR measurements were performed using flow-sensitive 2D phase-contrast MRI and a 9.4T preclinical scanner. The following hemodynamic parameters were investigated: portal cross-sectional area, mean portal flow velocity, and portal and aortic flow volume rate. Therefore, rats (n = 46) were divided into three groups: CON (control, n = 13), FIB (fibrosis, n = 25), and CIR (cirrhosis, n = 8). Furthermore, the degree of liver fibrosis was assessed by a self-established MR score and verified by a standardized histological score (n = 48). RESULTS Portal and aortic flow parameters could be reliably detected. A significant decrease in portal flow velocity was found in FIB (FIB vs. CON: -21%, P = 0.006 and CIR vs. CON: -17%, P = 0.105) and in portal flow volume rate in FIB and CIR (FIB vs. CON: -20%, P = 0.009 and CIR vs. CON: -25%, P = 0.024). If the histological score is taken as standard, the self-established MR score enabled discrimination between healthy and diseased livers (sensitivity to identify diseased livers: 89% and specificity to identify healthy livers: 100%). CONCLUSION This MR scanning protocol presents a noninvasive tool to determine hepatic hemodynamics in healthy and diseased rats. LEVEL OF EVIDENCE 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2017;46:1526-1534.
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Affiliation(s)
- Denise Schaffner
- Institute for Exercise- und Occupational Medicine, Medical Center, University of Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Germany.,Department of Pharmaceutical Biology and Biotechnology, University of Freiburg, Germany
| | - Dominik von Elverfeldt
- Faculty of Medicine, University of Freiburg, Germany.,Department of Radiology, Medical Physics, Medical Center, University of Freiburg, Germany
| | - Peter Deibert
- Institute for Exercise- und Occupational Medicine, Medical Center, University of Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Germany
| | - Adhara Lazaro
- Institute for Exercise- und Occupational Medicine, Medical Center, University of Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Germany
| | - Irmgard Merfort
- Department of Pharmaceutical Biology and Biotechnology, University of Freiburg, Germany
| | - Lisa Lutz
- Faculty of Medicine, University of Freiburg, Germany.,Institute of Clinical Pathology, Medical Center, University of Freiburg, Germany
| | - Jakob Neubauer
- Faculty of Medicine, University of Freiburg, Germany.,Department of Radiology, Medical Center, University of Freiburg, Germany
| | - Manfred W Baumstark
- Institute for Exercise- und Occupational Medicine, Medical Center, University of Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Germany
| | - Wolfgang Kreisel
- Faculty of Medicine, University of Freiburg, Germany.,Department of Medicine II, Gastroenterology, Hepatology, Endocrinology and Infectious Diseases, Medical Center, University of Freiburg, Germany
| | - Wilfried Reichardt
- Faculty of Medicine, University of Freiburg, Germany.,Department of Radiology, Medical Physics, Medical Center, University of Freiburg, Germany.,German Cancer Consortium (DKTK), Heidelberg, Germany.,German Cancer Research Center (DKFZ), Heidelberg, Germany
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29
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Palaniyappan N, Cox E, Bradley C, Scott R, Austin A, O’Neill R, Ramjas G, Travis S, White H, Singh R, Thurley P, Guha IN, Francis S, Aithal GP. Non-invasive assessment of portal hypertension using quantitative magnetic resonance imaging. J Hepatol 2016; 65:1131-1139. [PMID: 27475617 PMCID: PMC5123896 DOI: 10.1016/j.jhep.2016.07.021] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 07/19/2016] [Accepted: 07/21/2016] [Indexed: 12/15/2022]
Abstract
BACKGROUND & AIMS Hepatic venous pressure gradient (HVPG) measurement is currently the only validated technique to accurately evaluate changes in portal pressure. In this study, we evaluate the use of non-contrast quantitative magnetic resonance imaging (MRI) as a surrogate measure of portal pressure. METHODS Thirty patients undergoing HVPG measurement were prospectively recruited. MR parameters of longitudinal relaxation time (T1), perfusion of the liver and spleen (by arterial spin labelling), and blood flow in the portal, splanchnic and collateral circulation (by phase contrast MRI) were assessed. We estimated the liver stiffness measurement (LSM) and enhanced liver fibrosis (ELF) score. The correlation of all non-invasive parameters with HVPG was evaluated. RESULTS The mean (range) HVPG of the patients was 9.8 (1-22) mmHg, and 14 patients (48%) had clinically significant portal hypertension (CSPH, HVPG ⩾10mmHg). Liver T1 relaxation time, splenic artery and superior mesenteric artery velocity correlated significantly with HVPG. Using multiple linear regression, liver T1 and splenic artery velocity remained as the two parameters in the multivariate model significantly associated with HVPG (R=0.90, p<0.001). This correlation was maintained in patients with CSPH (R=0.85, p<0.001). A validation cohort (n=10) showed this linear model provided a good prediction of HVPG. LSM and ELF score correlated significantly with HVPG in the whole population but the correlation was absent in CSPH. CONCLUSIONS MR parameters related to both hepatic architecture and splanchnic haemodynamics correlate significantly with HVPG. This proposed model, confirmed in a validation cohort, could replace the invasive HVPG measurement. LAY SUMMARY In patients with cirrhosis, the development and progression of portal hypertension is related to worse outcomes. However, the standard technique of assessing portal pressure is invasive and not widely used in clinical practice. Here, we have studied the use of non-invasive MRI in evaluating portal pressure. The MRI measures of liver architecture and blood flow in the splenic artery correlated well with portal pressure. Therefore, this non-invasive method can potentially be used to assess portal pressure in clinical trials and monitoring treatment in practice.
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Affiliation(s)
- Naaventhan Palaniyappan
- National Institute for Health Research (NIHR) Nottingham Digestive Diseases Biomedical Research Unit, Nottingham University Hospitals NHS Trust and University of Nottingham, United Kingdom
| | - Eleanor Cox
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom
| | - Christopher Bradley
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom
| | - Robert Scott
- National Institute for Health Research (NIHR) Nottingham Digestive Diseases Biomedical Research Unit, Nottingham University Hospitals NHS Trust and University of Nottingham, United Kingdom
| | | | - Richard O’Neill
- Department of Radiology, Nottingham University Hospitals NHS Trust, Nottingham, United Kingdom
| | - Greg Ramjas
- Department of Radiology, Nottingham University Hospitals NHS Trust, Nottingham, United Kingdom
| | - Simon Travis
- Department of Radiology, Nottingham University Hospitals NHS Trust, Nottingham, United Kingdom
| | - Hilary White
- Department of Radiology, Nottingham University Hospitals NHS Trust, Nottingham, United Kingdom
| | | | | | - Indra Neil Guha
- National Institute for Health Research (NIHR) Nottingham Digestive Diseases Biomedical Research Unit, Nottingham University Hospitals NHS Trust and University of Nottingham, United Kingdom
| | - Susan Francis
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom
| | - Guruprasad Padur Aithal
- National Institute for Health Research (NIHR) Nottingham Digestive Diseases Biomedical Research Unit, Nottingham University Hospitals NHS Trust and University of Nottingham, United Kingdom.
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Chouhan MD, Lythgoe MF, Mookerjee RP, Taylor SA. Vascular assessment of liver disease-towards a new frontier in MRI. Br J Radiol 2016; 89:20150675. [PMID: 27115318 PMCID: PMC5124867 DOI: 10.1259/bjr.20150675] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Complex haemodynamic phenomena underpin the pathophysiology of chronic liver disease. Non-invasive MRI-based assessment of hepatic vascular parameters therefore has the potential to yield meaningful biomarkers for chronic liver disease. In this review, we provide an overview of vascular sequelae of chronic liver disease amenable to imaging evaluation and describe the current supportive evidence, strengths and the limitations of MRI methodologies, including dynamic contrast-enhanced, dynamic hepatocyte-specific contrast-enhanced, phase-contrast, arterial spin labelling and MR elastography in the assessment of hepatic vascular parameters. We review the broader challenges of quantitative hepatic vascular MRI, including the difficulties of motion artefact, complex post-processing, long acquisition times, validation and limitations of pharmacokinetic models, alongside the potential solutions that will shape the future of MRI and deliver this new frontier to the patient bedside.
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Affiliation(s)
- Manil D Chouhan
- 1 University College London (UCL) Centre for Medical Imaging, Division of Medicine, UCL, London, UK
| | - Mark F Lythgoe
- 2 University College London (UCL) Centre for Advanced Biomedical Imaging, Division of Medicine, UCL, London, UK
| | - Rajeshwar P Mookerjee
- 3 University College London (UCL) Institute for Liver and Digestive Health, Division of Medicine, UCL, London, UK
| | - Stuart A Taylor
- 1 University College London (UCL) Centre for Medical Imaging, Division of Medicine, UCL, London, UK
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31
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Chouhan MD, Mookerjee RP, Bainbridge A, Walker-Samuel S, Davies N, Halligan S, Lythgoe MF, Taylor SA. Use of Caval Subtraction 2D Phase-Contrast MR Imaging to Measure Total Liver and Hepatic Arterial Blood Flow: Preclinical Validation and Initial Clinical Translation. Radiology 2016; 280:916-23. [PMID: 27171018 PMCID: PMC5015842 DOI: 10.1148/radiol.2016151832] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Caval subtraction phase-contrast MR imaging is technically feasible and may offer a
reproducible and clinically viable method for measuring total liver blood flow and
hepatic arterial flow. Purpose To validate caval subtraction two-dimensional (2D) phase-contrast magnetic
resonance (MR) imaging measurements of total liver blood flow (TLBF) and hepatic
arterial fraction in an animal model and evaluate consistency and reproducibility
in humans. Materials and Methods Approval from the institutional ethical committee for animal care and research
ethics was obtained. Fifteen Sprague-Dawley rats underwent 2D phase-contrast MR
imaging of the portal vein (PV) and infrahepatic and suprahepatic inferior vena
cava (IVC). TLBF and hepatic arterial flow were estimated by subtracting
infrahepatic from suprahepatic IVC flow and PV flow from estimated TLBF,
respectively. Direct PV transit-time ultrasonography (US) and fluorescent
microsphere measurements of hepatic arterial fraction were the standards of
reference. Thereafter, consistency of caval subtraction phase-contrast MR
imaging–derived TLBF and hepatic arterial flow was assessed in 13
volunteers (mean age, 28.3 years ± 1.4) against directly measured
phase-contrast MR imaging PV and proper hepatic arterial inflow; reproducibility
was measured after 7 days. Bland-Altman analysis of agreement and coefficient of
variation comparisons were undertaken. Results There was good agreement between PV flow measured with phase-contrast MR imaging
and that measured with transit-time US (mean difference, −3.5 mL/min/100 g;
95% limits of agreement [LOA], ±61.3 mL/min/100 g). Hepatic arterial fraction
obtained with caval subtraction agreed well with those with fluorescent
microspheres (mean difference, 4.2%; 95% LOA, ±20.5%). Good consistency was
demonstrated between TLBF in humans measured with caval subtraction and direct
inflow phase-contrast MR imaging (mean difference, −1.3 mL/min/100 g; 95%
LOA, ±23.1 mL/min/100 g). TLBF reproducibility at 7 days was similar between
the two methods (95% LOA, ±31.6 mL/min/100 g vs ±29.6 mL/min/100 g). Conclusion Caval subtraction phase-contrast MR imaging is a simple and clinically viable
method for measuring TLBF and hepatic arterial flow. Online supplemental
material is available for this article.
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Affiliation(s)
- Manil D Chouhan
- From the University College London Centre for Medical Imaging (M.D.C., S.H., S.A.T.), Institute for Liver and Digestive Health (R.P.M., N.D.), and Centre for Advanced Biomedical Imaging (S.W.S., M.F.L.), Division of Medicine, University College London, 250 Euston Rd, 3rd Floor East, London NW1 2PG, England; and Department of Medical Physics, University College London Hospitals NHS Trust, London, England (A.B.)
| | - Rajeshwar P Mookerjee
- From the University College London Centre for Medical Imaging (M.D.C., S.H., S.A.T.), Institute for Liver and Digestive Health (R.P.M., N.D.), and Centre for Advanced Biomedical Imaging (S.W.S., M.F.L.), Division of Medicine, University College London, 250 Euston Rd, 3rd Floor East, London NW1 2PG, England; and Department of Medical Physics, University College London Hospitals NHS Trust, London, England (A.B.)
| | - Alan Bainbridge
- From the University College London Centre for Medical Imaging (M.D.C., S.H., S.A.T.), Institute for Liver and Digestive Health (R.P.M., N.D.), and Centre for Advanced Biomedical Imaging (S.W.S., M.F.L.), Division of Medicine, University College London, 250 Euston Rd, 3rd Floor East, London NW1 2PG, England; and Department of Medical Physics, University College London Hospitals NHS Trust, London, England (A.B.)
| | - Simon Walker-Samuel
- From the University College London Centre for Medical Imaging (M.D.C., S.H., S.A.T.), Institute for Liver and Digestive Health (R.P.M., N.D.), and Centre for Advanced Biomedical Imaging (S.W.S., M.F.L.), Division of Medicine, University College London, 250 Euston Rd, 3rd Floor East, London NW1 2PG, England; and Department of Medical Physics, University College London Hospitals NHS Trust, London, England (A.B.)
| | - Nathan Davies
- From the University College London Centre for Medical Imaging (M.D.C., S.H., S.A.T.), Institute for Liver and Digestive Health (R.P.M., N.D.), and Centre for Advanced Biomedical Imaging (S.W.S., M.F.L.), Division of Medicine, University College London, 250 Euston Rd, 3rd Floor East, London NW1 2PG, England; and Department of Medical Physics, University College London Hospitals NHS Trust, London, England (A.B.)
| | - Steve Halligan
- From the University College London Centre for Medical Imaging (M.D.C., S.H., S.A.T.), Institute for Liver and Digestive Health (R.P.M., N.D.), and Centre for Advanced Biomedical Imaging (S.W.S., M.F.L.), Division of Medicine, University College London, 250 Euston Rd, 3rd Floor East, London NW1 2PG, England; and Department of Medical Physics, University College London Hospitals NHS Trust, London, England (A.B.)
| | - Mark F Lythgoe
- From the University College London Centre for Medical Imaging (M.D.C., S.H., S.A.T.), Institute for Liver and Digestive Health (R.P.M., N.D.), and Centre for Advanced Biomedical Imaging (S.W.S., M.F.L.), Division of Medicine, University College London, 250 Euston Rd, 3rd Floor East, London NW1 2PG, England; and Department of Medical Physics, University College London Hospitals NHS Trust, London, England (A.B.)
| | - Stuart A Taylor
- From the University College London Centre for Medical Imaging (M.D.C., S.H., S.A.T.), Institute for Liver and Digestive Health (R.P.M., N.D.), and Centre for Advanced Biomedical Imaging (S.W.S., M.F.L.), Division of Medicine, University College London, 250 Euston Rd, 3rd Floor East, London NW1 2PG, England; and Department of Medical Physics, University College London Hospitals NHS Trust, London, England (A.B.)
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Stankovic Z. Four-dimensional flow magnetic resonance imaging in cirrhosis. World J Gastroenterol 2016; 22:89-102. [PMID: 26755862 PMCID: PMC4698511 DOI: 10.3748/wjg.v22.i1.89] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 08/08/2015] [Accepted: 10/13/2015] [Indexed: 02/06/2023] Open
Abstract
Since its introduction in the 1970’s, magnetic resonance imaging (MRI) has become a standard imaging modality. With its broad and standardized application, it is firmly established in the clinical routine and an essential element in cardiovascular and abdominal imaging. In addition to sonography and computer tomography, MRI is a valuable tool for diagnosing cardiovascular and abdominal diseases, for determining disease severity, and for assessing therapeutic success. MRI techniques have improved over the last few decades, revealing not just morphologic information, but functional information about perfusion, diffusion and hemodynamics as well. Four-dimensional (4D) flow MRI, a time-resolved phase contrast-MRI with three-dimensional (3D) anatomic coverage and velocity encoding along all three flow directions has been used to comprehensively assess complex cardiovascular hemodynamics in multiple regions of the body. The technique enables visualization of 3D blood flow patterns and retrospective quantification of blood flow parameters in a region of interest. Over the last few years, 4D flow MRI has been increasingly performed in the abdominal region. By applying different acceleration techniques, taking 4D flow MRI measurements has dropped to a reasonable scanning time of 8 to 12 min. These new developments have encouraged a growing number of patient studies in the literature validating the technique’s potential for enhanced evaluation of blood flow parameters within the liver’s complex vascular system. The purpose of this review article is to broaden our understanding of 4D flow MRI for the assessment of liver hemodynamics by providing insights into acquisition, data analysis, visualization and quantification. Furthermore, in this article we highlight its development, focussing on the clinical application of the technique.
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van der Beek CM, Bloemen JG, van den Broek MA, Lenaerts K, Venema K, Buurman WA, Dejong CH. Hepatic Uptake of Rectally Administered Butyrate Prevents an Increase in Systemic Butyrate Concentrations in Humans. J Nutr 2015; 145:2019-24. [PMID: 26156796 DOI: 10.3945/jn.115.211193] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 06/15/2015] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Short-chain fatty acids (SCFAs), fermentation products of undigested fibers, are considered beneficial for colonic health. High plasma concentrations are potentially harmful; therefore, information about systemic SCFA clearance is needed before therapeutic use of prebiotics or colonic SCFA administration. OBJECTIVE The aim of this study was to investigate the effect of rectal butyrate administration on SCFA interorgan exchange. METHODS Twelve patients (7 men; age: 66.4 ± 2.0 y; BMI 24.5 ± 1.4 kg/m(2)) undergoing upper abdominal surgery participated in this randomized placebo-controlled trial. During surgery, 1 group received a butyrate enema (100 mmol sodium butyrate/L; 60 mL; n = 7), and the other group a placebo (140 mmol 0.9% NaCl/L; 60 mL; n = 5). Before and 5, 15, and 30 min after administration, blood samples were taken from the radial artery, hepatic vein, and portal vein. Plasma SCFA concentrations were analyzed, and fluxes from portal-drained viscera, liver, and splanchnic area were calculated and used for the calculation of the incremental area under the curve (iAUC) over a 30-min period. RESULTS Rectal butyrate administration led to higher portal butyrate concentrations at 5 min compared with placebo (92.2 ± 27.0 μmol/L vs. 14.3 ± 3.4 μmol/L, respectively; P < 0.01). In the butyrate-treated group, iAUCs of gut release (282.8 ± 133.8 μmol/kg BW · 0.5 h) and liver uptake (-293.7 ± 136.0 μmol/kg BW · 0.5 h) of butyrate were greater than in the placebo group [-16.6 ± 13.4 μmol/kg BW · 0.5 h (gut release) and 16.0 ± 13.8 μmol/kg BW · 0.5 h (liver uptake); P = 0.01 and P < 0.05, respectively]. As a result, splanchnic butyrate release did not differ between groups. CONCLUSION After colonic butyrate administration, splanchnic butyrate release was prevented in patients undergoing upper abdominal surgery. These observations imply that therapeutic colonic SCFA administration at this dose is safe. The trial was registered at clinicaltrials.gov as NCT02271802.
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Affiliation(s)
- Christina M van der Beek
- Department of Surgery, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center+, Maastricht, Netherlands; Top Institute Food & Nutrition, Wageningen, Netherlands; and
| | - Johanne G Bloemen
- Department of Surgery, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center+, Maastricht, Netherlands; Top Institute Food & Nutrition, Wageningen, Netherlands; and
| | - Maartje A van den Broek
- Department of Surgery, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center+, Maastricht, Netherlands
| | - Kaatje Lenaerts
- Department of Surgery, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center+, Maastricht, Netherlands; Top Institute Food & Nutrition, Wageningen, Netherlands; and
| | - Koen Venema
- Top Institute Food & Nutrition, Wageningen, Netherlands; and Beneficial Microbes Consultancy, Wageningen, Netherlands
| | - Wim A Buurman
- Department of Surgery, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center+, Maastricht, Netherlands
| | - Cornelis H Dejong
- Department of Surgery, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center+, Maastricht, Netherlands; Top Institute Food & Nutrition, Wageningen, Netherlands; and
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Aguirre-Reyes DF, Sotelo JA, Arab JP, Arrese M, Tejos R, Irarrazaval P, Tejos C, Uribe SA, Andia ME. Intrahepatic portal vein blood volume estimated by non-contrast magnetic resonance imaging for the assessment of portal hypertension. Magn Reson Imaging 2015; 33:970-7. [PMID: 26117696 DOI: 10.1016/j.mri.2015.06.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 06/21/2015] [Indexed: 12/31/2022]
Abstract
PURPOSE To investigate the feasibility of estimating the portal vein blood volume that flows into the intrahepatic volume (IHPVBV) in each cardiac cycle using non-contrast MR venography technique as a surrogate marker of portal hypertension (PH). MATERIALS AND METHODS Ten patients with chronic liver disease and clinical symptoms of PH (40% males, median age: 54.0, range: 44-73 years old) and ten healthy volunteers (80% males, median age: 54.0, range: 44-66 years old) were included in this study. A non-contrast Triple-Inversion-Recovery Arterial-Spin-Labeling (TIR-ASL) technique was used to quantify the IHPVBV in one and two cardiac cycles. Liver (LV) and spleen volumes (SV) were measured by manual segmentation from anatomical MR images as morphological markers of PH. All images were acquired in a 1.5T Philips Achieva MR scanner. RESULTS PH patients had larger SV (P=0.02) and lower liver-to-spleen ratio (P=0.02) compared with healthy volunteers. The median IHPVBV in healthy volunteers was 13.5cm(3) and 26.5cm(3) for one and two cardiac cycles respectively, whereas in PH patients a median volume of 3.1cm(3) and 9.0cm(3) was observed. When correcting by LV, the IHPVBV was significantly higher in healthy volunteers than PH patients for one and two cardiac cycles. The combination of morphological information (liver-to-spleen ratio) and functional information (IHPVBV/LV) can accurately identify the PH patients with a sensitivity of 90% and specificity of 100%. CONCLUSION Results show that the portal vein blood volume that flows into the intrahepatic volume in one and two cardiac cycles is significantly lower in PH patients than in healthy volunteers and can be quantified with non-contrast MRI techniques.
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Affiliation(s)
- Daniel F Aguirre-Reyes
- Biomedical Imaging Center, Pontificia Universidad Catolica de Chile, Santiago, 7820436, Chile; Electrical Engineering Department, School of Engineering, Pontificia Universidad Catolica de Chile, Santiago, 7820436, Chile; Computation Sciences and Electronic Department, Universidad Tecnica Particular de Loja, Ecuador, Loja 1101608, Ecuador.
| | - Julio A Sotelo
- Biomedical Imaging Center, Pontificia Universidad Catolica de Chile, Santiago, 7820436, Chile; Electrical Engineering Department, School of Engineering, Pontificia Universidad Catolica de Chile, Santiago, 7820436, Chile.
| | - Juan P Arab
- Gastroenterology Department, School of Medicine, Pontificia Universidad Catolica de Chile, Santiago, 8331150, Chile.
| | - Marco Arrese
- Gastroenterology Department, School of Medicine, Pontificia Universidad Catolica de Chile, Santiago, 8331150, Chile.
| | - Rodrigo Tejos
- Gastroenterology Department, School of Medicine, Pontificia Universidad Catolica de Chile, Santiago, 8331150, Chile.
| | - Pablo Irarrazaval
- Biomedical Imaging Center, Pontificia Universidad Catolica de Chile, Santiago, 7820436, Chile; Electrical Engineering Department, School of Engineering, Pontificia Universidad Catolica de Chile, Santiago, 7820436, Chile.
| | - Cristian Tejos
- Biomedical Imaging Center, Pontificia Universidad Catolica de Chile, Santiago, 7820436, Chile; Electrical Engineering Department, School of Engineering, Pontificia Universidad Catolica de Chile, Santiago, 7820436, Chile.
| | - Sergio A Uribe
- Biomedical Imaging Center, Pontificia Universidad Catolica de Chile, Santiago, 7820436, Chile; Radiology Department, School of Medicine, Pontificia Universidad Catolica de Chile, Santiago, 8331150, Chile.
| | - Marcelo E Andia
- Biomedical Imaging Center, Pontificia Universidad Catolica de Chile, Santiago, 7820436, Chile; Radiology Department, School of Medicine, Pontificia Universidad Catolica de Chile, Santiago, 8331150, Chile.
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35
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Quantification of hepatic blood flow using a high-resolution phase-contrast MRI sequence with compressed sensing acceleration. AJR Am J Roentgenol 2015; 204:510-8. [PMID: 25714279 DOI: 10.2214/ajr.14.12597] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
OBJECTIVE. The objective of our study was to evaluate the performance of a high-spatial-resolution 2D phase-contrast (PC) MRI technique accelerated with compressed sensing for portal vein (PV) and hepatic artery (HA) flow quantification in comparison with a standard PC MRI sequence. SUBJECTS AND METHODS. In this prospective study, two PC MRI sequences were compared, one with parallel imaging acceleration and low spatial resolution (generalized autocalibrating partial parallel acquisition [GRAPPA]) and one with compressed sensing acceleration and high spatial resolution (sparse). Seventy-six patients were assessed, including 37 patients with cirrhosis. Two observers evaluated PC image quality. Quantitative analyses yielded a mean velocity, flow, and vessel area for the PV and HA and an arterial fraction. The PC techniques were compared using the paired Wilcoxon test and Bland-Altman statistics. The sensitivity of the flow parameters to the severity of cirrhosis was also assessed. RESULTS. Vessel delineation was significantly improved using the PC sparse sequence (p < 0.034). For both in vitro and in vivo measurements, PC sparse yielded lower estimates for vessel area and flow, and larger differences between PC GRAPPA and PC sparse were observed in the HA. PV velocity and flow were significantly lower in patients with cirrhosis on both PC sparse (p < 0.001 and p = 0.042, respectively) and PC GRAPPA (p < 0.001 and p = 0.005, respectively). PV velocity correlated negatively with Child-Pugh class (r = -0.50, p < 0.001), whereas the arterial fraction measured with PC sparse was higher in patients with Child-Pugh class B or C disease than in those with Child-Pugh class A disease, with a trend toward significance (p = 0.055). CONCLUSION. A high-spatial-resolution highly accelerated compressed sensing technique (PC sparse) allows total hepatic blood flow measurements obtained in 1 breath-hold, provides improved delineation of the hepatic vessels compared with a standard PC MRI sequence (GRAPPA), and can potentially be used for the noninvasive assessment of liver cirrhosis.
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Cox EF, Smith JK, Chowdhury AH, Lobo DN, Francis ST, Simpson J. Temporal assessment of pancreatic blood flow and perfusion following secretin stimulation using noninvasive MRI. J Magn Reson Imaging 2015; 42:1233-40. [PMID: 25787269 DOI: 10.1002/jmri.24889] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 03/05/2015] [Indexed: 01/12/2023] Open
Abstract
PURPOSE To dynamically quantify pancreatic perfusion and flow within the arteries supplying the pancreas in response to secretin stimulation. MATERIALS AND METHODS Twelve healthy male subjects were scanned at 1.5T with arterial spin labeling to measure tissue perfusion and phase contrast magnetic resonance imaging (MRI) to measure vessel flow. Superior mesenteric (SMA), gastroduodenal (GDA), common hepatic (HA), and splenic (SA) arterial flow and pancreatic perfusion were serially measured for 50 minutes following 1 IU/kg intravenous secretin. The significance of differences between timepoints was tested using a repeated measures one-way analysis of variance (ANOVA). RESULTS Baseline blood flow (mean ± SEM or median [IQR]) for SMA, HA, SA, and GDA was 7.6 ± 1.3, 4.0 ± 0.5, 8.2 ± 0.8, and 0.9 (0.8-1.4) ml/s, respectively. Baseline pancreatic perfusion was 200 ± 25 ml/100g/min. Blood flow increased in the SMA (234%, P < 0.0001) and GDA (155%, P = 0.015) immediately after secretin injection. Reduced HA blood flow was observed after 10 minutes (P = 0.066) with no change in SA flow (P = 0.533). Increased pancreatic perfusion was maintained for 40 minutes after injection with a maximal increase at 5 minutes (16.8%, P = 0.025). CONCLUSION Intravenous secretin resulted in significant temporal changes in pancreatic perfusion and arterial blood flow.
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Affiliation(s)
- Eleanor F Cox
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - Janette K Smith
- Division of Gastrointestinal Surgery, Nottingham Digestive Diseases Centre National Institute for Health Research Biomedical Research Unit, Nottingham University Hospitals NHS Trust and the University of Nottingham, Queen's Medical Centre, Nottingham, UK
| | - Abeed H Chowdhury
- Division of Gastrointestinal Surgery, Nottingham Digestive Diseases Centre National Institute for Health Research Biomedical Research Unit, Nottingham University Hospitals NHS Trust and the University of Nottingham, Queen's Medical Centre, Nottingham, UK
| | - Dileep N Lobo
- Division of Gastrointestinal Surgery, Nottingham Digestive Diseases Centre National Institute for Health Research Biomedical Research Unit, Nottingham University Hospitals NHS Trust and the University of Nottingham, Queen's Medical Centre, Nottingham, UK
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
| | - John Simpson
- Department of General Surgery, Harrogate District Hospital, Lancaster Park Road, Harrogate, N Yorks, UK
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Aubé C. Imaging modalities for the diagnosis of hepatic fibrosis and cirrhosis. Clin Res Hepatol Gastroenterol 2015; 39:38-44. [PMID: 25037179 DOI: 10.1016/j.clinre.2014.06.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 06/08/2014] [Indexed: 02/09/2023]
Abstract
Non-invasive methods for liver fibrosis diagnosis are now commonly used as first-intention tests for liver fibrosis diagnosis in chronic liver diseases. Even morphological parameters provided by ultrasound is now challenged by blood fibrosis tests and transient elastography, in experienced hands, it performed well and in certain situations, imaging can still be useful to detect patients with fibrosis. In parallel, to ultrasound and Doppler imaging, various methodologies have been explored. Some of them remain confined to clinical research for the moment, as perfusion, MR diffusion-weighted imaging, intravoxel incoherent motion or acoustic structure quantification; others have already taken a place in clinical practice. Regarding fast growing of new technology some methods may become available for daily practice in the near future. Ultrasound tools or automated quantification of different physical parameters of imaging data could provide an opportunity for early diagnosis of liver diseases; MRI techniques could lead to the development of a "global" liver examination.
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Affiliation(s)
- Christophe Aubé
- Département de radiologie, et laboratoire HIFIH, LUNAM université, université d'Angers, CHU d'Angers, 4, rue Larrey, 49933 Angers cedex, France.
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George SM, Eckert LM, Martin DR, Giddens DP. Hemodynamics in Normal and Diseased Livers: Application of Image-Based Computational Models. Cardiovasc Eng Technol 2014; 6:80-91. [DOI: 10.1007/s13239-014-0195-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 09/10/2014] [Indexed: 01/14/2023]
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Magnetic resonance imaging of the liver: apparent diffusion coefficients from multiexponential analysis of b values greater than 50 s/mm2 do not respond to caloric intake despite increased portal-venous blood flow. Invest Radiol 2014; 49:138-46. [PMID: 24169068 DOI: 10.1097/rli.0000000000000005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE The purpose of this study was to measure potential changes of the apparent diffusion coefficient (ADC) in diffusion-weighted imaging of the liver before and after caloric challenge in correlation to the induced changes in portal vein flow. MATERIALS AND METHODS The study was approved by the local ethics committee. Each of 10 healthy volunteers underwent 4 measurements in a 1.5-T whole-body magnetic resonance scanner on 2 different days: a first scan after fasting for at least 8 hours and a second scan 30 minutes after intake of a standardized caloric either a protein- or carbohydrate-rich meal. Diffusion-weighted spin-echo echo-planar magnetic resonance images were acquired at b values of 0, 50, 150, 250, 500, 750, and 1000 s/mm. In addition, portal vein flow was quantified with 2-dimensional phase-contrast imaging (velocity encoding parallel to flow direction, 60 cm/s). Mean ADC values for regions of interest in 3 different slices were measured from b50 to b250 and from b500 to b1000 images. RESULTS Carbohydrate- and protein-rich food intake both resulted in a substantial increase in the portal vein flow (fasting state, 638.6 ± 202.3 mL/min; after protein intake, 1322 ± 266.8; after carbohydrate intake, 1767 ± 421.6). The signal decay with increasingly strong diffusion weighting (b values from 0 to 1000 s/mm2) exhibited a triexponential characteristic, implying fast, intermediate, and slow-moving water-molecule proton-spin ensembles in the liver parenchyma. Mean ADC for high b values (b500-b1000) after fasting was 0.93 ± 0.09 × 10 mm/s; that after protein intake, 0.93 ± 0.11 × 10; and that after carbohydrate intake, 0.93 ± 0.08 × 10. For intermediate b values (b50-b250), the signal-decay constants were 1.27 ± 0.14 × 10 mm/s, 1.28 ± 0.15 × 10, and 1.31 ± 0.09 × 10, respectively. There was no statistically significant difference between fasting and caloric challenge. CONCLUSIONS The postprandial increase in portal vein flow is not accompanied by a change of liver parenchymal ADC values. In clinical diffusion imaging, patients may be scanned without prescan food-intake preparations. To minimize interference of perfusion effects, liver-tissue molecular water diffusion should be quantified using high b values (≥500 s/mm) only.
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Stankovic Z, Allen BD, Garcia J, Jarvis KB, Markl M. 4D flow imaging with MRI. Cardiovasc Diagn Ther 2014; 4:173-92. [PMID: 24834414 DOI: 10.3978/j.issn.2223-3652.2014.01.02] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 10/21/2013] [Indexed: 12/22/2022]
Abstract
Magnetic resonance imaging (MRI) has become an important tool for the clinical evaluation of patients with cardiovascular disease. Since its introduction in the late 1980s, 2-dimensional phase contrast MRI (2D PC-MRI) has become a routine part of standard-of-care cardiac MRI for the assessment of regional blood flow in the heart and great vessels. More recently, time-resolved PC-MRI with velocity encoding along all three flow directions and three-dimensional (3D) anatomic coverage (also termed '4D flow MRI') has been developed and applied for the evaluation of cardiovascular hemodynamics in multiple regions of the human body. 4D flow MRI allows for the comprehensive evaluation of complex blood flow patterns by 3D blood flow visualization and flexible retrospective quantification of flow parameters. Recent technical developments, including the utilization of advanced parallel imaging techniques such as k-t GRAPPA, have resulted in reasonable overall scan times, e.g., 8-12 minutes for 4D flow MRI of the aorta and 10-20 minutes for whole heart coverage. As a result, the application of 4D flow MRI in a clinical setting has become more feasible, as documented by an increased number of recent reports on the utility of the technique for the assessment of cardiac and vascular hemodynamics in patient studies. A number of studies have demonstrated the potential of 4D flow MRI to provide an improved assessment of hemodynamics which might aid in the diagnosis and therapeutic management of cardiovascular diseases. The purpose of this review is to describe the methods used for 4D flow MRI acquisition, post-processing and data analysis. In addition, the article provides an overview of the clinical applications of 4D flow MRI and includes a review of applications in the heart, thoracic aorta and hepatic system.
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Affiliation(s)
- Zoran Stankovic
- 1 Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, USA ; 2 Department Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, USA
| | - Bradley D Allen
- 1 Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, USA ; 2 Department Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, USA
| | - Julio Garcia
- 1 Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, USA ; 2 Department Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, USA
| | - Kelly B Jarvis
- 1 Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, USA ; 2 Department Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, USA
| | - Michael Markl
- 1 Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, USA ; 2 Department Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, USA
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Bigot A, Tremblay C, Soulez G, Martel S. Magnetic Resonance Navigation of a Bead Inside a Three-Bifurcation PMMA Phantom Using an Imaging Gradient Coil Insert. IEEE T ROBOT 2014. [DOI: 10.1109/tro.2014.2300591] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Jajamovich GH, Dyvorne H, Donnerhack C, Taouli B. Quantitative liver MRI combining phase contrast imaging, elastography, and DWI: assessment of reproducibility and postprandial effect at 3.0 T. PLoS One 2014; 9:e97355. [PMID: 24840288 PMCID: PMC4026225 DOI: 10.1371/journal.pone.0097355] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 04/17/2014] [Indexed: 12/13/2022] Open
Abstract
PURPOSE To quantify short-term reproducibility (in fasting conditions) and postprandial changes after a meal in portal vein (PV) flow parameters measured with phase contrast (PC) imaging, liver diffusion parameters measured with multiple b value diffusion-weighted imaging (DWI) and liver stiffness (LS) measured with MR elastography (MRE) in healthy volunteers and patients with liver disease at 3.0 T. MATERIALS AND METHODS In this IRB-approved prospective study, 30 subjects (11 healthy volunteers and 19 liver disease patients; 23 males, 7 females; mean age 46.5 y) were enrolled. Imaging included 2D PC imaging, multiple b value DWI and MRE. Subjects were initially scanned twice in fasting state to assess short-term parameter reproducibility, and then scanned 20 min. after a liquid meal. PV flow/velocity, LS, liver true diffusion coefficient (D), pseudodiffusion coefficient (D*), perfusion fraction (PF) and apparent diffusion coefficient (ADC) were measured in fasting and postprandial conditions. Short-term reproducibility was assessed in fasting conditions by measuring coefficients of variation (CV) and Bland-Altman limits of agreement. Differences in MR metrics before and after caloric intake and between healthy volunteers and liver disease patients were assessed. RESULTS PV flow parameters, D, ADC and LS showed good to excellent short-term reproducibility in fasting state (CV <16%), while PF and D* showed acceptable and poor reproducibility (CV = 20.4% and 51.6%, respectively). PV flow parameters and LS were significantly higher (p<0.04) in postprandial state while liver diffusion parameters showed no significant change (p>0.2). LS was significantly higher in liver disease patients compared to healthy volunteers both in fasting and postprandial conditions (p<0.001). Changes in LS were significantly correlated with changes in PV flow (Spearman rho = 0.48, p = 0.013). CONCLUSIONS Caloric intake had no/minimal/large impact on diffusion/stiffness/portal vein flow, respectively. PC MRI and MRE but not DWI should be performed in controlled fasting state.
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Affiliation(s)
- Guido H. Jajamovich
- Translational and Molecular Imaging Institute, Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, New York, United States
| | - Hadrien Dyvorne
- Translational and Molecular Imaging Institute, Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, New York, United States
| | - Claudia Donnerhack
- Translational and Molecular Imaging Institute, Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, New York, United States
| | - Bachir Taouli
- Translational and Molecular Imaging Institute, Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, New York, United States
- * E-mail:
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Shi Y, Guo Q, Xia F, Sun J, Gao Y. Short- and midterm repeatability of magnetic resonance elastography in healthy volunteers at 3.0 T. Magn Reson Imaging 2014; 32:665-70. [PMID: 24650683 DOI: 10.1016/j.mri.2014.02.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 02/10/2014] [Accepted: 02/11/2014] [Indexed: 02/07/2023]
Abstract
The purpose of this study was to evaluate the short- and midterm repeatability of liver stiffness measurements with magnetic resonance elastography (MRE) in healthy subjects at 3.0T. Twenty-two healthy volunteers were enrolled in this prospective study. The stiffness measurements were obtained from three slices with three repeated acquisitions for each slice (session 1) by two independent raters. After a mean period of 7±2days (session 2) and 195±15days (session 3), each subject was scanned again using the same protocol and MR system. The liver stiffness differences were calculated between sessions or raters. The intraclass correlation coefficient (ICC) was calculated to assess interrater agreement and intersession agreement. The stiffness differences over the short- and midterm intervals was (-0.004±0.086) kPa for sessions 1-2, lower than (-0.055±0.150) kPa for sessions 1-3 and (-0.051±0.173) kPa for sessions 2-3. The liver stiffness was more repeatable for the short-term interval with the mean overall ICC of 0.96 (sessions 1-2) (95% confidence interval [CI]: 0.90-0.98) compared with 0.91 (sessions 1-3) (95% CI: 0.78-0.96) and 0.87 (sessions 2-3) (95% CI: 0.69-0.95) for the midterm intervals. The overall ICC of interrater agreement was excellent at 0.987 (95% CI: 0.983 to 0.990). These results confirm that MRE is a reproducible technique for liver stiffness quantification over short- and midterm intervals up to 6months in a healthy population at 3.0T.
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Affiliation(s)
- Yu Shi
- Department of Radiology, Shengjing Hospital, China Medical University, No.36, Sanhao Street, Heping District, Shenyang, 110004, P.R. China
| | - Qiyong Guo
- Department of Radiology, Shengjing Hospital, China Medical University, No.36, Sanhao Street, Heping District, Shenyang, 110004, P.R. China.
| | - Fei Xia
- Department of Infectious Disease, Shengjing Hospital, China Medical University, No.36, Sanhao Street, Heping District, Shenyang, 110004, P.R. China
| | - Jiaxing Sun
- Department of Ultrasound, Shengjing Hospital, China Medical University, No.36, Sanhao Street, Heping District, Shenyang, 110004, P.R. China
| | - Yuying Gao
- Department of Radiology, Shengjing Hospital, China Medical University, No.36, Sanhao Street, Heping District, Shenyang, 110004, P.R. China
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Li L, Abdel-Sayed S, Berdajs D, Tozzi P, von Segesser LK, Ferrari E. Caval collapse during cardiopulmonary bypass: a reproducible bench model. Eur J Cardiothorac Surg 2014; 46:306-12. [DOI: 10.1093/ejcts/ezt620] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Stankovic Z, Jung B, Collins J, Russe MF, Carr J, Euringer W, Stehlin L, Csatari Z, Strohm PC, Langer M, Markl M. Reproducibility study of four-dimensional flow MRI of arterial and portal venous liver hemodynamics: influence of spatio-temporal resolution. Magn Reson Med 2013; 72:477-84. [PMID: 24018798 DOI: 10.1002/mrm.24939] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Revised: 08/01/2013] [Accepted: 08/08/2013] [Indexed: 12/22/2022]
Abstract
PURPOSE To evaluate influence of variation in spatio-temporal resolution and scan-rescan reproducibility on three-dimensional (3D) visualization and quantification of arterial and portal venous (PV) liver hemodynamics at four-dimensional (4D) flow MRI. METHODS Scan-rescan reproducibility of 3D hemodynamic analysis of the liver was evaluated in 10 healthy volunteers using 4D flow MRI at 3T with three different spatio-temporal resolutions (2.4 × 2.0 × 2.4 mm(3), 61.2 ms; 2.5 × 2.0 × 2.4 mm(3), 81.6 ms; 2.6 × 2.5 × 2.6 mm(3), 80 ms) and thus different total scan times. Qualitative flow analysis used 3D streamlines and time-resolved particle traces. Quantitative evaluation was based on maximum and mean velocities, flow volume, and vessel lumen area in the hepatic arterial and PV systems. RESULTS 4D flow MRI showed good interobserver variability for assessment of arterial and PV liver hemodynamics. 3D flow visualization revealed limitations for the left intrahepatic PV branch. Lower spatio-temporal resolution resulted in underestimation of arterial velocities (mean 15%, P < 0.05). For the PV system, hemodynamic analyses showed significant differences in the velocities for intrahepatic portal vein vessels (P < 0.05). Scan-rescan reproducibility was good except for flow volumes in the arterial system. CONCLUSION 4D flow MRI for assessment of liver hemodynamics can be performed with low interobserver variability and good reproducibility. Higher spatio-temporal resolution is necessary for complete assessment of the hepatic blood flow required for clinical applications.
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Affiliation(s)
- Zoran Stankovic
- Department of Radiology, Northwestern University, Chicago, Illinois, USA; Department of Biomedical Engineering, Northwestern University, Chicago, Illinois, USA; Department of Diagnostic Radiology and Medical Physics, University Medical Center Freiburg, Freiburg, Germany
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Morisaka H, Motosugi U, Ichikawa T, Sano K, Ichikawa S, Araki T, Enomoto N. MR-based measurements of portal vein flow and liver stiffness for predicting gastroesophageal varices. Magn Reson Med Sci 2013; 12:77-86. [PMID: 23666158 DOI: 10.2463/mrms.2012-0052] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
OBJECTIVES We evaluated flow parameters measured by phase-contrast magnetic resonance (MR) imaging (PC-MRI) of the portal venous system and liver stiffness measured by MR elastography (MRE) to determine the usefulness of these methods in predicting gastroesophageal varices (GEV) in patients with chronic liver disease (CLD). METHODS In patients with CLD and controls, we performed PC-MRI on the portal (PV) and superior mesenteric veins; calculated mean velocity (V, cm/s), cross-sectional area (S, mm²), and flow volume (Q, mL/min); and determined markers of liver fibrosis (liver stiffness [kPa]) and aspartate aminotransferase (AST) platelet ratio index [APRI]). We visually assessed GEV and development of collateral pathways of the PV on routine contrast-enhanced dynamic MR imaging and compared patient characteristics, flow parameters, liver stiffness markers, and visual analysis among 3GEV groups, those with mild, severe, or no GEV with reference to endoscopic findings. RESULTS Child-Pugh grade, VPV, SPV, liver stiffness, APRI, and visually identified GEV (visible GEV) differed significantly among the 3 groups (P<0.05). We investigated VPV, SPV, liver stiffness, and visible GEV as independent markers to distinguish patients with and without GEV and examined VPV and visible GEV to predict severe GEV. Visible GEV showed low sensitivity (14 to 30%) and high specificity (98%) for predicting GEV in patients with CLD. A subgroup analysis that excluded cases with collateral pathway demonstrated slightly improved diagnostic performance of VPV and liver stiffness. CONCLUSIONS Portal vein flow parameters and liver stiffness can be useful markers for predicting GEV in patients with CLD.
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Affiliation(s)
- Hiroyuki Morisaka
- Department of Radiology, University of Yamanashi, 1110 Shimokato, Chuo-shi, Yamanashi, Japan
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The accuracy of ultrasound volume flow measurements in the complex flow setting of a forearm vascular access. J Vasc Access 2012; 14:281-90. [PMID: 23172170 DOI: 10.5301/jva.5000118] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/30/2012] [Indexed: 11/20/2022] Open
Abstract
PURPOSE Maturation of an arterio-venous fistula (AVF) frequently fails, with low post-operative fistula flow as a prognostic marker for this event. As pulsed wave Doppler (PWD) is commonly used to assess volume flow, we studied the accuracy of this measurement in the setting of a radio-cephalic AVF. METHODS As in-vivo validation of fistula flow measurements is cumbersome, we performed simulations, integrating computational fluid dynamics with an ultrasound (US) simulator. Flow in the arm was calculated, based on a patient-specific model of the arm vasculature pre and post AVF creation. Raw ultrasound signals were subsequently simulated, from which Doppler spectra were calculated in both a proximal and a distal location. RESULTS The velocity component in the direction of the PWD-US beam (vPWD), in a centered, small, sample volume, can be captured accurately using PWD spectrum mean-tracking (maximum bias [mB] 8.1%). However, when deriving flow rate from these measurements, a high degree of inaccuracy occurs. First, the angle-correction of vPWD towards the velocity along the axis of the vessel is largely influenced by the radial velocity components in the complex flow field (mB=16.3%). Second, the largest error is introduced when transferring the centerline velocity to the cross-sectional mean velocity without any knowledge of the flow profile (mB=97.7%). CONCLUSIONS In the setting of a forearm AVF, flow estimates based on PWD are hampered by the complex flow patterns. Overall, flow estimation based on centerline measurement, analyzed by mean-tracking of the RF-spectral estimates, under the assumption of a parabolic flow profile, appeared to provide the most reasonable values.
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Accurate perioperative flow measurement of the portal vein and hepatic and renal artery: A role for preoperative MRI? Eur J Radiol 2012; 81:2042-8. [DOI: 10.1016/j.ejrad.2011.06.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Revised: 05/31/2011] [Accepted: 06/03/2011] [Indexed: 11/21/2022]
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Abduljalil K, Furness P, Johnson TN, Rostami-Hodjegan A, Soltani H. Anatomical, Physiological and Metabolic Changes with Gestational Age during Normal Pregnancy. Clin Pharmacokinet 2012; 51:365-96. [DOI: 10.2165/11597440-000000000-00000] [Citation(s) in RCA: 220] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Stankovic Z, Csatari Z, Deibert P, Euringer W, Blanke P, Kreisel W, Abdullah Zadeh Z, Kallfass F, Langer M, Markl M. Normal and altered three-dimensional portal venous hemodynamics in patients with liver cirrhosis. Radiology 2012; 262:862-73. [PMID: 22357888 DOI: 10.1148/radiol.11110127] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
PURPOSE To compare time-resolved three-dimensional (3D) phase-contrast magnetic resonance (MR) imaging with three-directional velocity encoding (flow-sensitive four-dimensional [4D] MR imaging), with Doppler ultrasonography (US) as standard of reference, for investigating alterations in 3D portal venous hemodynamics in patients with liver cirrhosis compared with healthy age-matched control subjects and healthy young volunteers. MATERIAL & METHODS This prospective study was approved by the local ethics committee, and written informed consent was obtained from all participants. Three-dimensional portal venous hemodynamics was assessed, employing flow-sensitive 4D MR imaging with a 3-T MR system (spatial resolution, approximately 2 mm(3); temporal resolution, approximately 45 msec) in 20 patients with hepatic cirrhosis, 20 healthy age-matched control subjects, and 21 healthy young volunteers. Flow characteristics were analyzed by using 3D streamlines and time-resolved particle traces. Quantitative analyses were performed by retrospectively evaluating regional peak and mean velocities, flow volume, and vessel area. Doppler US was used as standard of reference. Independent-sample t tests or Wilcoxon-Mann-Whitney tests were applied for comparing each subject group. Paired-sample t tests or Wilcoxon tests were applied when comparing MR imaging and US. RESULTS Three-dimensional visualization of portal venous hemodynamics was successful, with complete visualization of the vessels in 18 patients and 35 volunteers, with limitations in the left intrahepatic branches (87%, reader A; 89%, reader B). A moderate but significant correlation was observed between 4D MR imaging and Doppler US in nearly all maximum and mean velocities, flow volumes, and vessel areas (r = 0.24-0.64, P = .001-.044). With MR imaging, significant underestimation was observed of intrahepatic flow velocities and flow volumes, except vessel area, which Doppler US represented as even lower (P < .001 to P = .045). Six patients had collateralization with reopened umbilical vein, while one had flow reversal in the superior mesenteric vein visible at MR imaging only. CONCLUSION Flow-sensitive 4D MR imaging may constitute a promising, alternative technique to Doppler US for evaluating hemodynamics in the portal venous system of patients with liver cirrhosis and may be a means of assessing pathologic changes in flow characteristics.
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Affiliation(s)
- Zoran Stankovic
- Department of Diagnostic Radiology and Medical Physics, University Medical Center Freiburg, Hugstetter Strasse 55, 79106 Freiburg, Germany.
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