scholarly journals Haemodynamic changes in cirrhosis following terlipressin and induction of sepsis—a preclinical study using caval subtraction phase-contrast and cardiac MRI

2020 ◽  
Author(s):  
Manil D. Chouhan ◽  
Stuart A. Taylor ◽  
Alan Bainbridge ◽  
Simon Walker-Samuel ◽  
Nathan Davies ◽  
...  
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Cardiac Mri ◽  
Phase Contrast ◽  
Systolic Function ◽  
Cine Mri ◽  
Chronic Liver Failure ◽  
Cardiac Cine ◽  
Haemodynamic Changes ◽  
Cardiac Systolic Function

Abstract Objectives Effects of liver disease on portal venous (PV), hepatic arterial (HA), total liver blood flow (TLBF), and cardiac function are poorly understood. Terlipressin modulates PV flow but effects on HA, TLBF, and sepsis/acute-on-chronic liver failure (ACLF)-induced haemodynamic changes are poorly characterised. In this study, we investigated the effects of terlipressin and sepsis/ACLF on hepatic haemodynamics and cardiac function in a rodent cirrhosis model using caval subtraction phase-contrast (PC) MRI and cardiac cine MRI. Methods Sprague-Dawley rats (n = 18 bile duct–ligated (BDL), n = 16 sham surgery controls) underwent caval subtraction PCMRI to estimate TLBF and HA flow and short-axis cardiac cine MRI for systolic function at baseline, following terlipressin and lipopolysaccharide (LPS) infusion, to model ACLF. Results All baseline hepatic haemodynamic/cardiac systolic function parameters (except heart rate and LV mass) were significantly different in BDL rats. Following terlipressin, baseline PV flow (sham 181.4 ± 12.1 ml/min/100 g; BDL 68.5 ± 10.1 ml/min/100 g) reduced (sham − 90.3 ± 11.1 ml/min/100 g, p < 0.0001; BDL − 31.0 ± 8.0 ml/min/100 g, p = 0.02), sham baseline HA flow (33.0 ± 11.3 ml/min/100 g) increased (+ 92.8 ± 21.3 ml/min/100 g, p = 0.0003), but BDL baseline HA flow (83.8 ml/min/100 g) decreased (− 34.4 ± 7.5 ml/min/100 g, p = 0.11). Sham baseline TLBF (214.3 ± 16.7 ml/min/100 g) was maintained (+ 2.5 ± 14.0 ml/min/100 g, p > 0.99) but BDL baseline TLBF (152.3 ± 18.7 ml/min/100 g) declined (− 65.5 ± 8.5 ml/min/100 g, p = 0.0004). Following LPS, there were significant differences between cohort and change in HA fraction (p = 0.03) and TLBF (p = 0.01) with BDL baseline HA fraction (46.2 ± 4.6%) reducing (− 20.9 ± 7.5%, p = 0.03) but sham baseline HA fraction (38.2 ± 2.0%) remaining unchanged (+ 2.9 ± 6.1%, p > 0.99). Animal cohort and change in systolic function interactions were significant only for heart rate (p = 0.01) and end-diastolic volume (p = 0.03). Conclusions Caval subtraction PCMRI and cardiac MRI in a rodent model of cirrhosis demonstrate significant baseline hepatic haemodynamic/cardiac differences, failure of the HA buffer response post-terlipressin and an altered HA fraction response in sepsis, informing potential translation to ACLF patients. Key Points Caval subtraction phase-contrast and cardiac MRI demonstrate: • Significant differences between cirrhotic/non-cirrhotic rodent hepatic blood flow and cardiac systolic function at baseline. • Failure of the hepatic arterial buffer response in cirrhotic rodents in response to terlipressin. • Reductions in hepatic arterial flow fraction in the setting of acute-on-chronic liver failure.

Variations in blood flow waveforms in stenotic renal arteries by 2D phase-contrast cine MRI

1998 ◽  
Vol 8 (3) ◽  
pp. 590-597 ◽  
Author(s):  
Jos J. M. Westenberg ◽  
Martin N. J. M. Wasser ◽  
Rob J. van der Geest ◽  
Peter M. T. Pattynama ◽  
Albert de Roos ◽  
...  
Keyword(s):  
Blood Flow ◽  
Phase Contrast ◽  
Renal Arteries ◽  
Cine Mri ◽  
Flow Waveforms

scholarly journals Rank-One and Transformed Sparse Decomposition for Dynamic Cardiac MRI

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Xianchao Xiu ◽  
Lingchen Kong
Keyword(s):  
Cardiac Mri ◽  
Low Rank ◽  
Cine Mri ◽  
Sparse Decomposition ◽  
Sparse Model ◽  
Cardiac Cine ◽  
Rank One ◽  
Magnetic Resonance Imaging Mri ◽  
Alternative Direction Method ◽  
Space Data

It is challenging and inspiring for us to achieve high spatiotemporal resolutions in dynamic cardiac magnetic resonance imaging (MRI). In this paper, we introduce two novel models and algorithms to reconstruct dynamic cardiac MRI data from under-sampledk-tspace data. In contrast to classical low-rank and sparse model, we use rank-one and transformed sparse model to exploit the correlations in the dataset. In addition, we propose projected alternative direction method (PADM) and alternative hard thresholding method (AHTM) to solve our proposed models. Numerical experiments of cardiac perfusion and cardiac cine MRI data demonstrate improvement in performance.

Cine MRI phase contrast measurements of entrance blood flow in the aorta

2004 ◽  
Vol 2004.6 (0) ◽  
pp. 207-208
Author(s):  
Suguru YOKOSAWA ◽  
Masanori NAKAMURA ◽  
Shigeo WADA ◽  
Ken-ichi TSUBOTA ◽  
Takami YAMAGUCHI ◽  
...  
Keyword(s):  
Blood Flow ◽  
Phase Contrast ◽  
Cine Mri

scholarly journals Feasibility of phase-contrast cine magnetic resonance imaging for measuring blood flow in the sheep fetus

2019 ◽  
Vol 317 (6) ◽  
pp. R780-R792 ◽  
Author(s):  
An Qi Duan ◽  
Jack R. T. Darby ◽  
Jia Yin Soo ◽  
Mitchell C. Lock ◽  
Meng Yuan Zhu ◽  
...  
Keyword(s):  
Blood Flow ◽  
Phase Contrast ◽  
Interobserver Agreement ◽  
Main Pulmonary Artery ◽  
Ductus Venosus ◽  
Cine Mri ◽  
Flow Measurements ◽  
Fetal Sheep ◽  
Fetal Circulation ◽  
Arterial Blood

Phase-contrast cine MRI (PC-MRI) is the gold-standard noninvasive technique for measuring vessel blood flow and has previously been applied in the human fetal circulation. We aimed to assess the feasibility of using PC-MRI to define the distribution of the fetal circulation in sheep. Fetuses were catheterized at 119–120 days of gestation (term, 150 days) and underwent MRI at ∼123 days of gestation under isoflurane anesthesia, ventilated at a [Formula: see text] of 1.0. PC-MRI was performed using a fetal arterial blood pressure catheter signal for cardiac triggering. Blood flows were measured in the major fetal vessels, including the main pulmonary artery, ascending and descending aorta, superior vena cava, ductus arteriosus, left and right pulmonary arteries, umbilical vein, ductus venosus, and common carotid artery and were indexed to estimated fetal weight. The combined ventricular output, pulmonary blood flow, and flow across the foramen ovale were calculated from vessel flows. Intraobserver and interobserver agreement and reproducibility was assessed. Blood flow measurements were successfully obtained in 61 out of 74 vessels (82.4%) interrogated in 9 fetuses. There was good intraobserver [ R = 0.998, P < 0.0001; intraclass correlation (ICC) = 0.997] and interobserver agreement ( R = 0.996, P < 0.0001; ICC = 0.996). Repeated MRI measurements showed good reproducibility ( R = 0.989, P = 0.0002; ICC = 0.990). We conclude that PC-MRI using fetal catheters for gating triggers is feasible in the major vessels of late gestation fetal sheep. This approach may provide a useful new tool for assessing the circulatory characteristics of fetal sheep models of human disease, including fetal growth restriction and congenital heart disease.

Differences in Reflex Control of Arterial Pressure and Renin Release during Head-Up Tilting in the Cat

1978 ◽  
Vol 55 (s4) ◽  
pp. 179s-181s ◽  
Author(s):  
A. Stella ◽  
R. A. L. Dampney ◽  
R. Golin ◽  
A. Zanchetti
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Arterial Pressure ◽  
Renin Release ◽  
Haemodynamic Response ◽  
First Episode ◽  
Haemodynamic Changes ◽  
Cervical Vagotomy ◽  
Reflex Control

1. Anaesthetized cats were subjected to two 10 min trials of head-up tilting spaced 30 min. Arterial pressure, heart rate, blood flow to an innervated kidney and to the contralateral denervated one, and renin release from both kidneys were measured. 2. The same haemodynamic changes and comparable increases in renin release from innervated kidneys occurred during both episodes of tilting when cats were subjected to sham cervical vagotomy between the two tilting trials. 3. Bilateral cervical vagotomy, performed after the first episode of head-up tilting, did not affect the haemodynamic response to the change in posture, but significantly and markedly reduced the increase in renin release from the innervated kidney. 4. After sino-aortic denervation a marked and sustained arterial hypotension occurred during tilting, and the postural increase in renin release from the innervated kidney was even greater. 5. In no condition, even during the marked fall in blood pressure in sino-aortic denervated cats, did head-up tilting increase renin release from the denervated kidney. 6. It is concluded that maintenance of arterial pressure during tilting is mainly due to sino-aortic reflexes, whereas vagal reflexes are mostly responsible for the postural increase in renin release.

scholarly journals Fast Phase-Contrast Cine MRI for Assessing Intracranial Hemodynamics and Cerebrospinal Fluid Dynamics

Diagnostics ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 241 ◽  
Author(s):  
Naoki Ohno ◽  
Tosiaki Miyati ◽  
Tomohiro Noda ◽  
Noam Alperin ◽  
Takashi Hamaguchi ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebrospinal Fluid ◽  
Phase Contrast ◽  
Free Breathing ◽  
Breath Holding ◽  
Cine Mri ◽  
Breath Hold ◽  
Fast Phase ◽  
Full Inspiration ◽  
Conventional Methods

We propose fast phase-contrast cine magnetic resonance imaging (PC-cine MRI) to allow breath-hold acquisition, and we compared intracranial hemo- and hydrodynamic parameters obtained during breath holding between full inspiration and end expiration. On a 3.0 T MRI, using electrocardiogram (ECG)-synchronized fast PC-cine MRI with parallel imaging, rectangular field of view, and segmented k-space, we obtained velocity-mapped phase images at the mid-C2 level with different velocity encoding for transcranial blood flow and cerebrospinal-fluid (CSF) flow. Next, we calculated the peak-to-peak amplitudes of cerebral blood flow (ΔCBF), cerebral venous outflow, intracranial volume change, CSF pressure gradient (ΔPG), and intracranial compliance index. These parameters were compared between the proposed and conventional methods. Moreover, we compared these parameters between different utilized breath-hold maneuvers (inspiration, expiration, and free breathing). All parameters derived from the fast PC method agreed with those from the conventional method. The ΔPG was significantly higher during full inspiration breath holding than at the end of expiration and during free breathing. The proposed fast PC-cine MRI reduced scan time (within 30 s) with good agreement with conventional methods. The use of this method also makes it possible to assess the effects of respiration on intracranial hemo- and hydrodynamics.

Non-invasive quantification of pulmonary blood flow in pediatric patients using phase-contrast cine MRI

2005 ◽  
Vol 1281 ◽  
pp. 1303
Author(s):  
Masayuki Kumashiro ◽  
Kenji Waki ◽  
Kenya Murase ◽  
Takashi Tabuchi ◽  
Takashi Kiyono ◽  
...  
Keyword(s):  
Blood Flow ◽  
Pulmonary Blood Flow ◽  
Phase Contrast ◽  
Pediatric Patients ◽  
Cine Mri ◽  
Non Invasive

Segmentation of Biventricle in Cardiac Cine MRI via Nested Capsule Dense Network

2021 ◽  
Author(s):  
Yuhang Hu ◽  
Yajuan Zhang ◽  
Hongyang Zhang ◽  
Weihao Shen ◽  
Shoujun Zhou ◽  
...  
Keyword(s):  
Cardiac Mri ◽  
Spatial Information ◽  
Cine Mri ◽  
Cardiac Magnetic Resonance Image ◽  
Dense Network ◽  
Evaluation Standard ◽  
Cardiac Cine ◽  
Proposed Model ◽  
Physiological Indexes ◽  
Cardiac Diagnosis

Abstract Cardiac magnetic resonance image (MRI) has been widely used in diagnosis of cardiovascular diseases because of its noninvasive nature and high image quality. The evaluation standard of physiological indexes in cardiac diagnosis is essentially the accuracy of segmentation of left ventricle (LV) and right ventricle (RV) in cardiac MRI. In this paper, we propose a novel Nested Capsule Dense Network (NCDN) structure based on the FC-DenseNet model and capsule convolution-capsule deconvolution. Different from the traditional symmetric single codec network structure such as U-net, NCDN uses multiple codecs instead of a single codec to achieve multi-resolution, which makes it possible to save more spatial information and improve the robustness of the model. The proposed model is tested on three datasets that includes York University Cardiac MRI dataset, Automated Cardiac Diagnosis Challenge (ACDC-2017), and local dataset. The results show that the proposed NCDN outperforms the state-of-the-art methods.

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