Development of a Methodology for Direct Utilization of Phase-Contrast MRI in Hemodynamic Computations

2011 ◽  
Author(s):  
Ashish Das ◽  
William M. Gottliebson ◽  
Janaka Wansapura ◽  
Rupak K. Banerjee
Keyword(s):  
Blood Flow ◽  
Phase Contrast ◽  
Pulmonary Insufficiency ◽  
Patient Specific ◽  
Non Invasive ◽  
Diagnostic Indices ◽  
Specific Geometry ◽  
Uniform Cross Section ◽  
Flow Through ◽  
Use Phase

Development of non-invasive diagnostic indices often requires accurate blood-flow calculation using physiologically realistic velocity profiles as boundary conditions. In this research, a methodology is being developed and validated that can directly use phase-contrast MR imaging (PC-MRI) based velocity measurement to perform blood-flow computation with patient-specific geometry. Using this methodology, the pressure drop can also be calculated non-invasively. Although the main focus of our research has been pulmonary insufficiency (PI) in tetralogy patients, our method can be employed in many other pathophysiologies. As a pilot study, the methodology is tested using a simple model of blood-flow through a straight artery of uniform cross-section.

Application and In situ calibration of a pulsed-doppler flowmeter for blood flow measurement in crustaceans

1994 ◽  
Vol 74 (2) ◽  
pp. 455-458 ◽  
Author(s):  
C.N. Airriess ◽  
B.R. McMahon ◽  
I.J. McGaw ◽  
G.B. Bourne
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
The Body ◽  
Pulsed Doppler ◽  
Arterial Perfusion ◽  
Non Invasive ◽  
In Situ Calibration ◽  
Flow Through ◽  
Doppler Flowmeter

The pulsed-Doppler flowmeter permits continuous, non-invasive measurement of blood flow through several arteries simultaneously. Summation of volume flow rates through all arteries leaving the heart allows determination of cardiac output, stroke volume, and the percentage of cardiac output delivered to each region of the body. The use of this system for investigating changes in arterial perfusion as well as its calibration in situ are described.

scholarly journals Phase-contrast magnetic resonance imaging to assess renal perfusion: a systematic review and statement paper

2019 ◽  
Vol 33 (1) ◽  
pp. 3-21 ◽  
Author(s):  
Giulia Villa ◽  
Steffen Ringgaard ◽  
Ingo Hermann ◽  
Rebecca Noble ◽  
Paolo Brambilla ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Systematic Review ◽  
Blood Flow ◽  
Clinical Practice ◽  
Magnetic Resonance ◽  
Kidney Disease ◽  
Phase Contrast ◽  
Resonance Imaging ◽  
Non Invasive ◽  
Contrast Magnetic Resonance

Abstract Objective Phase-contrast magnetic resonance imaging (PC-MRI) is a non-invasive method used to compute blood flow velocity and volume. This systematic review aims to discuss the current status of renal PC-MRI and provide practical recommendations which could inform future clinical studies and its adoption in clinical practice. Methodology A comprehensive search of all the PC-MRI studies in human healthy subjects or patients related to the kidneys was performed. Results A total of 39 studies were included in which PC-MRI was used to measure renal blood flow (RBF) alongside other derivative hemodynamic parameters. PC-MRI generally showed good correlation with gold standard methods of RBF measurement, both in vitro and in vivo, and good reproducibility. Despite PC-MRI not being routinely used in clinical practice, there are several clinical studies showing its potential to support diagnosis and monitoring of renal diseases, in particular renovascular disease, chronic kidney disease and autosomal dominant polycystic kidney disease. Discussion Renal PC-MRI shows promise as a non-invasive technique to reliably measure RBF, both in healthy volunteers and in patients with renal disease. Future multicentric studies are needed to provide definitive normative ranges and to demonstrate the clinical potential of PC-MRI, likely as part of a multi-parametric renal MRI protocol.

MATHEMATICAL MODELING OF STROKE VOLUME FROM THE PERIPHERAL BLOOD FLOW FOR NON INVASIVE PLETHYSMOGRAPHIC MEASUREMENT OF CARDIAC OUTPUT AND ITS VALIDATION

2017 ◽  
Vol 29 (06) ◽  
pp. 1750041
Author(s):  
Pranali Choudhari ◽  
M. S. Panse
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Peripheral Blood ◽  
Clinical Medicine ◽  
Patient Specific ◽  
Peripheral Blood Flow ◽  
Lung Water ◽  
Non Invasive ◽  
Multiple Variable

The ability to accurately measure Cardiac Output (CO) is important in clinical medicine as it helps in improving diagnosis of abnormalities and appropriate disease management. In spite of being an important vital parameter, it is still missing from the screens of the bedside monitors employed today. This could be due to the invasiveness of the method or the discomfort in the measurement. Invasive methods are most accurate but can be best suited for the intensive care units (ICUs) and surgeries, but for bedside measurement these methods add an unnecessary risk to the life of the patient. The existing non-invasive method employed for CO measurement is the thoracic bioimpedance method, which is risky for patients with cardiovascular diseases and inaccurate for patients with extra vascular lung water. This paper presents a novel method of CO measurement from the peripheral blood flow, which fairly overcomes the disadvantages of the existing method. The impedance pulse has been acquired across the wrist, instead of the thorax. A new stroke volume equation has been modeled by carrying out the finite element simulation of the blood flow and multiple variable regression to incorporate the patient specific factors. The stroke volume thus obtained has been validated for 57 subjects.

Simulation of Blood Flow in Deformable Arteries Using Subject-Specific Geometry and Variable Vessel Wall Properties

2009 ◽  
Author(s):  
Guanglei Xiong ◽  
C. Alberto Figueroa ◽  
Nan Xiao ◽  
Charles A. Taylor
Keyword(s):  
Blood Flow ◽  
Geometric Model ◽  
Cerebral Aneurysms ◽  
Patient Specific ◽  
Wall Properties ◽  
Subject Specific ◽  
Vessel Wall Properties ◽  
Specific Geometry ◽  
Variable Wall ◽  
Dynamics Simulations

Previous efforts to simulate blood flow in patient-specific models either assumed rigid vessel walls or deformable walls with constant mechanical property [1]. We have developed a new workflow to enable blood flow and vessel dynamics simulations using subject-specific geometry and variable wall properties. The geometric model construction is based on 3D segmentation and geometric processing which greatly reduce human labor and increase the objectivity of the model. Variable wall properties are assigned to the model based on combining centerline-based and surface-based methods. This new approach was successfully applied to simulate blood flow and wall dynamics in models with abdominal, thoracic, and cerebral aneurysms.

Application of a locally conservative Galerkin (LCG) method for modelling blood flow through a patient-specific carotid bifurcation

2010 ◽  
Vol 64 (10-12) ◽  
pp. 1274-1295 ◽  
Author(s):  
R. L. T. Bevan ◽  
P. Nithiarasu ◽  
R. Van Loon ◽  
I. Sazonov ◽  
H. Luckraz ◽  
...  
Keyword(s):  
Blood Flow ◽  
Carotid Bifurcation ◽  
Patient Specific ◽  
Flow Through ◽  
Locally Conservative

scholarly journals Comparison of non-invasive MRI measurements of cerebral blood flow in a large multisite cohort

2016 ◽  
Vol 36 (7) ◽  
pp. 1244-1256 ◽  
Author(s):  
Sudipto Dolui ◽  
Ze Wang ◽  
Danny JJ Wang ◽  
Raghav Mattay ◽  
Mack Finkel ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Arterial Spin Labeling ◽  
Phase Contrast ◽  
Spin Labeling ◽  
Flow Measurements ◽  
Entire Cohort ◽  
Non Invasive ◽  
Global Cerebral Blood Flow ◽  
Continuous Arterial Spin Labeling

Arterial spin labeling and phase contrast magnetic resonance imaging provide independent non-invasive methods for measuring cerebral blood flow. We compared global cerebral blood flow measurements obtained using pseudo-continuous arterial spin labeling and phase contrast in 436 middle-aged subjects acquired at two sites in the NHLBI CARDIA multisite study. Cerebral blood flow measured by phase contrast (CBFPC: 55.76 ± 12.05 ml/100 g/min) was systematically higher ( p < 0.001) and more variable than cerebral blood flow measured by pseudo-continuous arterial spin labeling (CBFPCASL: 47.70 ± 9.75). The correlation between global cerebral blood flow values obtained from the two modalities was 0.59 ( p < 0.001), explaining less than half of the observed variance in cerebral blood flow estimates. Well-established correlations of global cerebral blood flow with age and sex were similarly observed in both CBFPCASL and CBFPC. CBFPC also demonstrated statistically significant site differences, whereas no such differences were observed in CBFPCASL. No consistent velocity-dependent effects on pseudo-continuous arterial spin labeling were observed, suggesting that pseudo-continuous labeling efficiency does not vary substantially across typical adult carotid and vertebral velocities, as has previously been suggested. Conclusions: Although CBFPCASL and CBFPC values show substantial similarity across the entire cohort, these data do not support calibration of CBFPCASL using CBFPC in individual subjects. The wide-ranging cerebral blood flow values obtained by both methods suggest that cerebral blood flow values are highly variable in the general population.

scholarly journals Effective Computational Framework for Pre-Interventional Planning of Peripheral Arteriovenous Malformations with In Vivo and In Vitro Validation

2021 ◽  
Author(s):  
Gaia Franzetti ◽  
Mirko Bonfanti ◽  
Cyrus Tanade ◽  
Chung Sim Lim ◽  
Janice Tsui ◽  
...  
Keyword(s):  
Blood Flow ◽  
Computational Model ◽  
Arteriovenous Malformations ◽  
Clinical Decision Making ◽  
Patient Specific ◽  
Post Intervention ◽  
Computational Framework ◽  
Mock Circulatory System ◽  
Flow Through

Purpose: Peripheral arteriovenous malformations (pAVMs) are congenital lesions characterised by abnormal high-flow, low-resistance vascular connections - constituting the so-called nidus - between arteries and veins. The mainstay treatment typically involves the embolisation of the nidus with embolic and sclerosant agents, however the complexity of AVMs often leads to uncertain outcomes. This study aims at developing a simple, yet effective computational framework to aid the clinical decision making around the treatment of pAVMs. Methods: A computational model was developed to simulate the pre-, intra-, and post-intervention haemodynamics of an AVM. A porous medium of varying permeability was used to simulate the effect that the sclerosant has on the blood flow through the nidus. The computational model was informed by computed tomography (CT) scans and digital subtraction angiography (DSA) images, and the results were compared against clinical data and experimental results. Results: The computational model was able to simulate the blood flow through the AVM throughout the intervention and predict (direct and indirect) haemodynamic changes due to the embolisation. The simulated transport of the dye in the AVM was compared against DSA time-series obtained at different intervention stages, providing confidence in the results. Moreover, experimental data obtained via a mock circulatory system involving a patient specific 3D printed phantom of the same AVM provided further validation of the simulation results. Conclusion: We developed a simple computational framework to simulate AVM haemodynamics and predict the effects of the embolisation procedure. The developed model lays the foundation of a new, computationally driven treatment planning tool for AVM embolisation procedures.

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