scholarly journals Analysis of 3-Dimensional Arch Anatomy, Vascular Flow, and Postnatal Outcome in Cases of Suspected Coarctation of the Aorta Using Fetal Cardiac Magnetic Resonance Imaging

2021 ◽  
Author(s):  
David F.A. Lloyd ◽  
Milou P.M. van Poppel ◽  
Kuberan Pushparajah ◽  
Trisha V. Vigneswaran ◽  
Vita Zidere ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Blood Flow ◽  
Phase Contrast ◽  
Fetal Mri ◽  
Coarctation Of The Aorta ◽  
Resonance Imaging ◽  
3 Dimensional ◽  
Aortic Isthmus ◽  
Vascular Flow ◽  
Postnatal Outcome

Background: Identifying fetuses at risk of severe neonatal coarctation of the aorta (CoA) can be lifesaving but is notoriously challenging in clinical practice with a high rate of false positives. Novel fetal 3-dimensional and phase-contrast magnetic resonance imaging (MRI) offers an unprecedented means of assessing the human fetal cardiovascular system before birth. We performed detailed MRI assessment of fetal vascular morphology and flows in a cohort of fetuses with suspected CoA, correlated with the need for postnatal intervention. Methods: Women carrying a fetus with suspected CoA on echocardiography were referred for MRI assessment between 26 and 36 weeks of gestation, including high-resolution motion-corrected 3-dimensional volumes of the fetal heart and phase-contrast flow sequences gated with metric optimized gating. The relationship between aortic geometry and vascular flows was then analyzed and compared with postnatal outcome. Results: Seventy-two patients (51 with suspected fetal CoA and 21 healthy controls) underwent fetal MRI with motion-corrected 3-dimensional vascular reconstructions. Vascular flow measurements from phase-contrast sequences were available in 53 patients. In the CoA group, 25 of 51 (49%) required surgical repair of coarctation after birth; the remaining 26 of 51 (51%) were discharged without neonatal intervention. Reduced blood flow in the fetal ascending aorta and at the aortic isthmus was associated with increasing angulation ( P =0.005) and proximal displacement ( P =0.006) of the isthmus and was seen in both true positive and false positive cases. A multivariate logistic regression model including aortic flow and isthmal displacement explained 78% of the variation in outcome and correctly predicted the need for intervention in 93% of cases. Conclusions: Reduced blood flow though the left heart is associated with important configurational changes at the aortic isthmus in fetal life, predisposing to CoA when the arterial duct closes after birth. Novel fetal MRI techniques may have a role in both understanding and accurately predicting severe neonatal CoA.

scholarly journals Aging Effects on Cerebral Blood and Cerebrospinal Fluid Flows

2007 ◽  
Vol 27 (9) ◽  
pp. 1563-1572 ◽  
Author(s):  
Souraya Stoquart-ElSankari ◽  
Olivier Balédent ◽  
Catherine Gondry-Jouet ◽  
Malek Makki ◽  
Olivier Godefroy ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Blood Flow ◽  
Cerebrospinal Fluid ◽  
Magnetic Resonance ◽  
Phase Contrast ◽  
The Elderly ◽  
Elderly Group ◽  
Resonance Imaging ◽  
Aging Effects ◽  
Contrast Magnetic Resonance

Phase-contrast magnetic resonance imaging (PC-MRI) is a noninvasive reliable technique, which enables quantification of cerebrospinal fluid (CSF) and total cerebral blood flows (tCBF). Although it is used to study hydrodynamic cerebral disorders in the elderly group (hydrocephalus), there is no published evaluation of aging effects on both tCBF and CSF flows, and on their mechanical coupling. Nineteen young (mean age 27 ± 4 years) and 12 elderly (71 ± 9 years) healthy volunteers underwent cerebral MRI using 1.5 T scanner. Phase-contrast magnetic resonance imaging pulse sequence was performed at the aqueductal and cervical levels. Cerebrospinal fluid and blood flow curves were then calculated over the cardiac cycle, to extract the characteristic parameters: mean and peak flows, their latencies, and stroke volumes for CSF (cervical and aqueductal) and vascular flows. Total cerebral blood flow was ( P < 0.01) decreased significantly in the elderly group when compared with the young subjects with a linear correlation with age observed only in the elderly group ( R2 = 0.7; P = 0.05). Arteriovenous delay was preserved with aging. The CSF stroke volumes were significantly reduced in the elderly, at both aqueductal ( P < 0.01) and cervical ( P < 0.05) levels, whereas aqueduct/cervical proportion ( P = 0.9) was preserved. This is the first work to study aging effects on both CSF and vascular cerebral flows. Data showed (1) tCBF decrease, (2) proportional aqueductal and cervical CSF pulsations reduction as a result of arterial loss of pulsatility, and (3) preserved intracerebral compliance with aging. These results should be used as reference values, to help understand the pathophysiology of degenerative dementia and cerebral hydrodynamic disorders as hydrocephalus.

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.

scholarly journals Phase-contrast magnetic resonance imaging and computational fluid dynamics assessment of thoracic aorta blood flow: a literature review

2019 ◽  
Author(s):  
Omar A Jarral ◽  
Matthew K H Tan ◽  
Mohammad Yousuf Salmasi ◽  
Selene Pirola ◽  
John R Pepper ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Blood Flow ◽  
Cardiovascular Magnetic Resonance ◽  
Magnetic Resonance ◽  
Cardiovascular Magnetic Resonance Imaging ◽  
Phase Contrast ◽  
Aortic Disease ◽  
Flow Patterns ◽  
Health Concern ◽  
Resonance Imaging

Abstract The death rate from thoracic aortic disease is on the rise and represents a growing global health concern as patients are often asymptomatic before acute events, which have devastating effects on health-related quality of life. Biomechanical factors have been found to play a major role in the development of both acquired and congenital aortic diseases. However, much is still unknown and translational benefits of this knowledge are yet to be seen. Phase-contrast cardiovascular magnetic resonance imaging of thoracic aortic blood flow has emerged as an exceptionally powerful non-invasive tool enabling visualization of complex flow patterns, and calculation of variables such as wall shear stress. This has led to multiple new findings in the areas of phenotype-dependent bicuspid valve flow patterns, thoracic aortic aneurysm formation and aortic prosthesis performance assessment. Phase-contrast cardiovascular magnetic resonance imaging has also been used in conjunction with computational fluid modelling techniques to produce even more sophisticated analyses, by allowing the calculation of haemodynamic variables with exceptional temporal and spatial resolution. Translationally, these technologies may potentially play a major role in the emergence of precision medicine and patient-specific treatments in patients with aortic disease. This clinically focused review will provide a systematic overview of key insights from published studies to date.

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