SAYAKA SHIRAI¹, Tetsuro Sekine¹, Kenichiro Takahashi¹, Jiro Kurita¹, Yosuke Ishii¹, and Shinichiro Kumita^1
1Nippon Medical School Hospital, Tokyoto Bunkyoku, Japan

To investigate whether turbulent kinetic energy measurement around anastomosis can be used as a predictor for residual aortic expansion after aortic replacement for type A aortic dissection. The TKEpeak of AoR group was significantly higher than those of volunteers (15.12 ± 7.06 [3.51–28.38] vs. 4.50 ± 1.64 [2.57–8.13] mJ, p < 0.001). There was a strong correlation between the annual expansion rate and distal TKEpeak (R²=0.818).

Liwei Hu¹, Xiaodan Zhao², Rongzhen Ouyang¹, Shuang Leng², Yong Zhang³, Liang Zhong^2,4, and Yumin Zhong^1
1Shanghai Children's Medical Center, Shanghai, China, ²National Heart Centre Singapore, Singapore, Singapore, ³GE Healthcare, Shanghai, China, ⁴Duke-NUS Medical School, National University of Singapore, singapore, Singapore

Four-dimensional flow (4D flow) magnetic resonance imaging (MRI) enables the quantification of blood flow such as kinetic energy (KE) and flow components within the ventricular. Both KE and flow components is associated with ventricular diastolic and systolic function. This study aimed to quantify left ventricular (LV) KE and flow components in repaired Fontan patients in comparison to normal volunteers. The data showed that LV diastolic and systolic KE and direct flow were significant reduced, and residual flow increased in repaired Fontan patients.

Cody Johnson¹, Ryan Pewowaruk², David Rutkowski¹, Amanda Wolfinger¹, and Alejandro Roldán-Alzate^1,2,3
1Radiology, University of Wisconsin-Madison, MADISON, WI, United States, ²Biomedical Engineering, University of Wisconsin-Madison, MADISON, WI, United States, ³Mechanical Engineering, University of Wisconsin-Madison, Madison, WI, United States

To gain insight into male-female differences in cardiovascular conditions, understanding healthy, sex differences is critical. We analyzed 20 healthy subjects with cardiac 4D flow MRI data (10 male and 10 female) to quantify LV and aortic flow, and ventricular vascular coupling (VVC) of KE and vorticity. The sex difference found in LV flow were not found in aortic flow. The VVC of LV-to-aortic flow was similar for men and women. The analysis methods and results of this study may be of further use in understanding ventricular vascular coupling of flow variables in various cardiovascular conditions.

Amanda L DiCarlo¹, Justin Baraboo^1,2, Patrick McCarthy³, Rishi Arora⁴, Rod Passman⁴, Philip Greenland⁴, Daniel C Lee^1,4, Daniel Kim^1,2, and Michael Markl^1,2
1Radiology, Northwestern University, Chicago, IL, United States, ²Biomedical Engineering, Northwestern University, Chicago, IL, United States, ³Cardiac Surgery, Northwestern University, Chicago, IL, United States, ⁴Cardiology, Northwestern University, Chicago, IL, United States

Atrial fibrillation (AF) is the most common cardiac arrhythmia, characterized by irregular heart rhythm which can lead to stroke due to thrombus formation in the left atrium (LA) or left atrial appendage (LAA). Reduced velocities and increased stasis measured with 4D flow MRI are risk metrics correlated with LA thrombus formation and potential predictors of stroke. This study analyzed the relationship between heart rate variability derived from a real time MRI acquisition and 4D flow hemodynamic risk metrics. LA peak velocity and stasis were significantly correlated with heart rate variability, suggesting a link between rhythm status and thrombus risk.

Rick J. van Tuijl¹, Jonas W. Bartstra¹, Pim A. de Jong¹, Willem P. T. M. Mali¹, Irene C. van der Schaaf¹, Ynte M. Ruigrok², Gabriël J. E. Rinkel², Birgitta K. Velthuis¹, Wilko Jason Spiering³, and Jaco J. M. Zwanenburg^1
1Radiology, UMC Utrecht, Utrecht, Netherlands, ²Neurology, UMC Utrecht, Utrecht, Netherlands, ³Vascular Medicine, UMC Utrecht, Utrecht, Netherlands

Arterial internal elastic lamina calcifications in pseudoxanthoma elasticum (PXE) may reduce the normal attenuation by the carotid siphon. This could contribute to increased intracranial pulsatility seen in PXE patients. We compared velocity pulsatility and distensibility along the internal carotid artery and in the middle cerebral artery between 50 PXE patients and 40 age and sex-matched controls, using 2D phase-contrast velocity mapping on 3T MRI. Distensibility was lower and pulsatility higher in patients. However, pulsatility attenuation over the siphon was similar between patients and controls. Siphon dysfunction does, therefore, not explain the increased intracranial arterial pulsatility in PXE.

Tetsuro Sekine¹, Erika Orita¹, Takahiro Ando¹, Yasuo Murai¹, and Shinichiro Kumita^1
1Nippon Medical School, Tokyo, Japan

The purpose of this study was to clarify the intracranial hemodynamics before and after superficial temporal artery to middle cerebral artery (STA-MCA) bypass surgery by comparing flow parameters obtained by time-resolved 3-dimensional phase-contrast (4D flow) MRI and intraoperative MCA pressure measurement.

The visual and quantitative assessment of 4D flow MRI revealed that intracranial blood flow changes complementarily after STA-MCA bypass surgery. The sum of intracranial BFV can be used for the evaluation of treatment outcome after the surgery.

Masataka Sugiyama¹, Yasuo Takehara¹, Shinji Naganawa², Satoshi Goshima³, Atsushi Nozaki⁴, Tetsuya Wakayama⁴, and Marcus Alley^5
1Department of Fundamental Development for Advanced Low Invasive Diagnostic Imaging, Nagoya University, Graduate School of Medicine, Nagoya, Japan, ²Department of Radiology, Nagoya University, Graduate School of Medicine, Nagoya, Japan, ³Department of Radiology, Hamamatsu University School of Medicine, Hamamatsu, Japan, ⁴Applied Science Laboratory Asia Pacific, GE Healthcare Japan, Hino, Japan, ⁵Department of Radiology, Stanford University School of Medicine, Palo Alto, CA, United States

4D Flow MRI were performed for 12 abdominal aortic aneurysm patients who underwent EVAR before and after the treatment. Peak systolic blood flow in the common iliac arteries has significantly increased after EVAR (right: p=0.016, left: p=0.016). The aneurysm might have stored blood like a reservoir in systole and have inhibited the delivery of blood flow to the iliac arteries.  The stent placement of EVAR may have repaired the deformed blood flow path and improved the efficiency of blood flow delivery to the periphery. 4D Flow have shown its power for analyzing the hemodynamic effects of EVAR.

Laiyang Ma¹, Chuang Wu¹, Na Han¹, Jing Zhang¹, and Kai Ai^2
1LanZhou University Second Hospital, LanZhou, China, ²Philips Healthcare, Xi'an, China

The purpose of this study was to evaluate the hemodynamic changes in the cerebral arterial of healthy adults among different ages and anatomical locations by using 4D flow MRI. We measured blood flow volume, velocity, wall shear stress (WSS) of cerebral arterial. The hemodynamic changes among different groups were significantly distinct. The young group showed significantly higher in velocity and WSS. Velocity and WSS were decreased with age. The proximal posterior cerebral artery (pro-PCA) had lower volume, velocity and WSS than other parts. 4D Flow MRI could quantify the change of hemodynamics parameters in the cerebral arterial of healthy adults.

Huaxia Pu¹, Haoyao Cao², Yubo Fan³, Jinge Zhang¹, Zhenlin Li¹, Zhan Liu², Liqing Peng¹, Tinghui Zheng², Xiaoyue Zhou⁴, and Ning Jin^5
1Department of Radiology, West China Hospital, Sichuan University, Chengdu, China, ²Department of Applied Mechanics, Sichuan University, Chengdu, China, ³Key Laboratory for Biomechanics and Mechanobiology of the Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China, ⁴MR Collaboration, Siemens Healthineers Ltd, Shanghai, China, ⁵Siemens Medical Solutions USA, Chicago, IL, United States

The existence of helical flow in the superior vena cava (SVC) is not well understood in vivo. 4D flow MRI data of the SVC and brachiocephalic veins (BVs) were acquired in 8 healthy young males. SVC hemodynamic parameters, including velocity, pathlines, streamlines, and flow waveforms, were measured using a specialized post-processing software. Helical flow was present in the normal SVC. The flow pathlines from the right and left BVs formed helical flows, respectively, with two development types: twining and untwining. These findings may elucidate the occurrence and development of potential SVC disease.

Yasuhiro Goto¹, Michinobu Nagao¹, Masami Yoneyama², Yasutomo Katsumata², Isao Shiina³, Kazuo Kodaira¹, Takumi Ogawa¹, Yutaka Hamatani³, Mamoru Takeyama³, Isao Tanaka¹, and Shuji Sakai^1
1Women's Medical University Hospital, tokyo, Japan, ²Philips Japan, tokyo, Japan, ³Tokyo Women's Medical University Hospital, tokyo, Japan

Since the REPI 4D MRA images the entire cardiac cycle, it may be possible to visualize the flow of the pulmonary artery, pulmonary vein, left ventricle, left ventricle, and aorta in addition to morphological evaluation of the coronary artery.The purpose of this study was to examine mainly LAD about the possibility of the practical use of REPI 4D MRA. REPI 4D MRA with choice of the VENC=30 cm/s could well visualize the coronary arteries from proximal to distal of the LAD.

Na Han¹, Chuang Wu¹, Laiyang Ma¹, Yurong Ma¹, Jing Zhang¹, and Kai Ai^2
1Department of Magnetic Resonance, Lanzhou University Second Hospital, Lanzhou, China, ²Philips Healthcare, Xi'an, China

The multi-parameter analysis of 4D flow MRI can identify the changes of hemodynamic parameters in different anatomical location of intracranial arteries. This study evaluating the hemodynamic changes (volume, velocity, wall shear stress) in the intracranial arteries of young secondary hypertensive patients among different anatomical locations (ICA-C3, ICA-C7, proximal MCA, proximal PCA, middle BA) using 4D flow MRI. The proximal PCA had significantly lower volume, velocity and wall shear stress than the values determined for other locations. The wall shear stress at the anatomical location of ICA-C3 was decreased in young secondary hypertensive patients.

Michinobu Nagao¹, Yumi Shiina¹, Yasuhiro Goto¹, Isao Shiina¹, Kazuo Kodaira¹, Masami Yoneyama², Takashi Namiki², Yuka Matsuo¹, Atsushi Yamamoto¹, Kei Inai¹, and Shuji Sakai^1
1Tokyo Women's Medical University, Tokyo, Japan, ²Philips Japan, Tokyo, Japan

We propose a free-breathing 4D flow sequence with echo-planar imaging (EPI) and rapid reconstruction to facilitate clinical use. Pulmonary stenosis or atresia is a common anatomic component of congenital conotruncal anomaly. Multi-VENC 4D flow MRI with EPI can simultaneously visualize the pulmonary artery stenosis and associated collaterals of slow flow formed by peripheral arteries. Consequently, all sources of pulmonary blood supply and of the size and morphology of the pulmonary arteries can be completely delineated.

Lihua Chen¹, Ailian Liu¹, Jiazheng Wang², Yishi Wang², and Qingwei Song^1
1The First Affiliated Hospital of Dalian Medical University, Dalian, China, ²Philips Healthcare, Beijing, China

Liver MRI was conducted with both 4D-Flow and APTw imaging before and after a meal challenge. After the meal, significantly increased blood flow velocity and volume were observed in portal vein (PV) and superior mesenteric vein (SMV) and significantly decreased blood flow was observed in splenic vein (PV), while no change was observed in APT values (MTRasym) in liver parenchyma after the meal.

Maurice Pradella^1,2, Michael B Scott¹, Brad D Allen¹, Ryan Avery¹, and Michael Markl^1,3
1Department of Radiology, Northwestern University, Chicago, IL, United States, ²University Hospital Basel, University of Basel, Basel, Switzerland, ³Department Biomedical Engineering, Northwestern University, Chicago, IL, United States

We present initial results of our novel full chest, free-breathing 4D-flow protocol which was designed for clinical use. In 25 patient who required imaging of aortic and pulmonic flow, it proved to be feasible for two reasons: mean acquisition times of 4D-flow was 12.5min versus 9.7min for 2D phase contrast (2D-PC) imaging, resulting in only a minor mean measurement time increase of about three minutes. Second, flow measurements for aortic and pulmonic flow for were consistent for both 4D-flow and 2D-PC. We will continue with our evaluation in a larger cohort to confirm these initial results.

Rihab Mansour¹, Narges Salehi², William Tanguay^1,3, Guillaume Gilbert⁴, Catherine Huet¹, Gilles Soulez¹, Pierre Perreault¹, Damien Olivé ¹, An Tang^1,3, and Samuel Kadoury^1,2
1Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Montréal, QC, Canada, ²École Polytechnique, Montréal, QC, Canada, ³Department of Radiology, Radio-Oncology and Nuclear Medicine, Université de Montréal, Montréal, QC, Canada, ⁴MR Clinical Science, Philips Healthcare Canada, Markham, ON, Canada

4D flow MRI measurements in the abdominal aorta, common hepatic artery, and proper hepatic arteries are feasible and provide repeatable values before and after transarterial chemoembolization in patients with hepatocellular carcinoma. Blood flow showed no statistically significant change before and after transarterial chemoembolization in the abdominal aorta, common hepatic artery, and proper hepatic artery based on a Wilcoxon test (P = 0.87, 0.72, and 0.86 respectively).

Labib Shahid¹, James Rice¹, Haben Berhane², Cynthia Rigsby³, Joshua Robinson³, Lindsay Griffin³, Michael Markl², and Alejandro Roldán-Alzate^1
1University of Wisconsin-Madison, Madison, WI, United States, ²Northwestern University, Chicago, IL, United States, ³Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, United States

CMR is used for diagnosis of COA and post-intervention assessment. Current limitations of 4D flow MRI include insufficient spatio-temporal resolution, inability to image low velocity regions, and distortion of image due to stent. The presented MRI-based computational enhancement method addresses stated limitations. Patient specific flow velocities defined the boundary conditions for numerical simulations. CFD simulations with AMR were run on segmented aorta geometries. Comparison between in-vivo and CFD results show good agreement, and residual complex flows post-repair compared to healthy control. Computational enhancement of 4D flow MRI can be used as a predictive tool in future clinical settings. 

Marc Delaney¹, Vincent Cleveland², Paige Mass², Francesco Capuano³, Yue-Hin Loke⁴, and Laura Olivieri^4
1Pediatrics, Children's National Hospital, Washington, DC, United States, ²Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Hospital, Washington, DC, United States, ³Industrial Engineering, Universita di Napoli Federico II, Naples, Italy, ⁴Pediatric Cardiology, Children's National Hospital, Washington, DC, United States

Repair of D- transposition of great arteries (DTGA) involves pulmonary artery (PA) manipulation that alters shape and flow patterns. Many patients experience increased right ventricular afterload and the etiology remains unclear. We examined the contribution of PA flow separation to afterload in these patients using 4D flow CMR imaging of a mock circulatory system incorporating 3D-printed PA replicas. We found that 2 distinct markers of flow inefficiency correlated with afterload. These data emphasize the utility of 4D flow CMR in quantifying abnormal blood flow  and identifying important early clinical predictors of complications in DTGA.

Elizabeth Weiss¹, Kelly Jarvis¹, Chris Malaisrie², Patrick McCarthy², Robert Bonow³, James Carr¹, Cynthia Rigsby⁴, and Michael Markl^1
1Radiology, Northwestern University, Chicago, IL, United States, ²Cardiothoracic Surgery, Northwestern University, Chicago, IL, United States, ³Cardiology, Northwestern University, Chicago, IL, United States, ⁴Radiology, Lurie Children's Hospital, Chicago, IL, United States

Bicuspid Aortic Valve (BAV) patients often develop aortic dilation which can lead to life-threatening complications. Voxel-wise reverse flow was calculated to assess deranged flow in BAV patients with dilation and in healthy volunteers. In BAV patients, the mean reverse flow was significantly increased in the ascending aorta and aortic arch. The reverse flow volume (volume with reverse flow>0.03mL/cycle) was also increased. Linear regression demonstrated that these reverse flow metrics were significant contributors to mid-ascending aorta diameter even when age was accounted for. We demonstrated that reverse flow is a significant component of deranged flow in BAV disease.

Lihua Chen¹, Ailian Liu¹, Jiazheng Wang², Yishi Wang², and Qingwei Song^1
1The First Affiliated Hospital of Dalian Medical University, Dalian, China, ²Philips Healthcare, China, Beijing, China

Because of the development of compressed sensing (CS) technology in both spatial and temporal related data acquisition, four-dimensional flow MRI scan can be accomplished in a clinically acceptable time. We evaluated the highly accelerated four-dimensional flow magnetic resonance imaging in portal system hemodynamics studies with Compressed SENSE (CS-SENSE). There was no statistically significant difference in flow velocity, volume rate, axial-WSS of portal system when compared among different CS, measurements from the two observers matched well with each other.

Wenwen Chen¹, Xiaowei Song², Shuo Chen¹, Mingzhu Fu¹, Hanyu Wei¹, Duoduo Hou², Le Chen², Miaoqi Zhang¹, Jian Wu², and Rui Li^1
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, ²Beijing Tsinghua Changgung Hospital, Beijing, China

Intracranial atherosclerosis disease (ICAD) can induce blood flow lateralization (BFL). However, the relationship of infarct patterns (IPs) with BFL was rarely explored. This study investigated the relationship between BFL and IPs in middle cerebral artery (MCA) using 4D flow MRI. Twenty-eight patients with unilateral MCA infarction were included. Average net flow (Flow_avg) of infarction side and the contralateral side of MCA-M1 were compared in various IPs. Flow_avg is significantly different between two sides of MCA in cortical infarct, but not significant in subcortical lesions. This suggests that cortical infarct may be the specific pattern for BFL in MCA.