Through cardiac looping during embryonic development, paths of flow through the mature heart have direction changes and asymmetries whose topology and functional significance remain relatively unexplored. Here we show, using magnetic resonance velocity mapping, the asymmetric redirection of streaming blood in atrial and ventricular cavities of the adult human heart, with sinuous, chirally asymmetric paths of flow through the whole. On the basis of mapped flow fields and drawings that illustrate spatial relations between flow paths, we propose that asymmetries and curvatures of the looped heart have potential fluidic and dynamic advantages. Patterns of atrial filling seem to be asymmetric in a manner that allows the momentum of inflowing streams to be redirected towards atrio-ventricular valves, and the change in direction at ventricular level is such that recoil away from ejected blood is in a direction that can enhance rather than inhibit ventriculo-atrial coupling. Chiral asymmetry might help to minimize dissipative interaction between entering, recirculating and outflowing streams. These factors might combine to allow a reciprocating, sling-like, 'morphodynamic' mode of action to come into effect when heart rate and output increase during exercise.

Helical and retrograde streams are consistent features of intra-aortic flow in healthy subjects that result, at least in part, from the curvature of the arch and the pulsatility of flow in it. They may have significance in relation to circulatory dynamics and the pathogenesis of atheroma in the arch.

Midwall fibrosis was an independent predictor of mortality in patients with moderate and severe aortic stenosis. It has incremental prognostic value to ejection fraction and may provide a useful method of risk stratification.

A review of cardiovascular clinical and research applications of MRI phase-contrast velocity imaging, also known as velocity mapping or flow imaging. Phase-contrast basic principles, advantages, limitations, common pitfalls and artefacts are described. It can measure many different aspects of the complicated blood flow in the heart and vessels: volume flow (cardiac output, shunt, valve regurgitation), peak blood velocity (for stenosis), patterns and timings of velocity waveforms and flow distributions within heart chambers (abnormal ventricular function) and vessels (pulse-wave velocity, vessel wall disease). The review includes phase-contrast applications in cardiac function, heart valves, congenital heart diseases, major blood vessels, coronary arteries and myocardial wall velocity.

Sildenafil added to conventional treatment reduces RV mass and improves cardiac function and exercise capacity in patients with PAH, WHO functional class III. Safety monitoring is important until more experience is obtained.

HighlightsThis work presents the methodologies and evaluation results for the WHS algorithms selected from the submissions to the Multi-Modality Whole Heart Segmentation (MM-WHS) challenge, in conjunction with MICCAI 2017.This work introduces the related information to the challenge, discusses the results from the conventional methods and deep learning-based algorithms, and provides insights to the future research.The challenge provides a fair and intuitive comparison framework for methods developed and being developed for WHS.The challenge provides the training datasets with manually delineated ground truths and evaluation for an ongoing development of MM-WHS algorithms.

SUMMARY Arterial compliance was measured in 70 healthy volunteers, 13 athletes, and 17 patients with coronary artery disease. Magnetic resonance images were acquired at end diastole and end systole through the ascending aorta, the aortic arch, and the descending thoracic aorta. Regional compliance was derived from the change in luminal area in a slice of known thickness and from the pulse pressure. Total arterial compliance was also measured from the left ventricular stroke volume and the pulse pressure. In the volunteers, mean (SD) regional compliance (Ml/mm Hg) was greatest in the ascending aorta (37 (18)), lower in the arch (31 (15)), and lowest in the descending aorta (18 (8)), and it decreased with age. Compliance in the athletes was significantly higher than in their age matched controls (41 (16) versus 22 (11) 1l/mm Hg). In the patients with coronary artery disease it was significantly lower (12 (4) v 18 (10)) than in age matched controls. Total arterial compliance also fell with age in those with coronary artery disease although there was more variation.The results suggest a possible role for compliance in the assessment of cardiovascular fitness and the detection of coronary artery disease.A popular saying is that a man is as old as his arteries. The commonest arterial disease is "hardening of the arteries" or atherosclerosis which leads, among other things, to a loss of elasticity. Arterial elasticity is measured as compliance, which is the change in volume per unit change in pressure, and compliance measurements may be valuable for both detection and monitoring of disease.Magnetic resonance imaging is a direct noninvasive way of studying regional aortic compliance and total arterial compliance. We used it to study changes in compliance with age and aortic compliance in athletes and in patients with coronary artery disease. Patients and methodsWe studied 70 Accepted for publication 7 March 1989 13 athletes (mean age 43, range 29-56), and 17 patients with coronary artery disease without previous infarction (mean age 53, range 30-76). Three of the athletes were of international standard (one Olympic gold medal) and the others were club athletes. The average distance run daily was nine miles.We used a Picker International Vista MR2055 machine operating at 0-5 T to acquire images at end diastole and end systole in three oblique planes perpendicular to the midpoints of the ascending aorta, the aortic arch, and the descending thoracic aorta (fig 1). A spin echo sequence (TE 40 ms) was used with two averages of 128 phase encoding steps, a pixel size of 1417 mm x 1-17 mm, and a slice thickness of 10 mm. The end diastolic images were acquired 100 ms before the average RR interval, and the end systolic images at the end ofthe T wave ofthe electrocardiogram Acquisition time was three to four minutes per image depending upon heart rate.The lumen of the aorta was outlined manually on the computer screen, and regional aortic compliance was calculated from the change in volume between diastole and systole. The p...

We have used magnetic resonance imaging with cine velocity mapping to measure flow wave velocity in the thoracic aorta of 20 healthy volunteers of different ages. We have also studied the relationship between propagation of flow wave velocity and regional aortic compliance. Aortic flow velocity increased linearly with age (r = 0.87), and there was a significant difference between the youngest decade [age 10-19, mean velocity 4.3 +/- 0.7 (SD) m/s] and the oldest decade studied (age 50-59, mean velocity 7.2 +/- 0.2 m/s). Flow wave velocity (m/s) was negatively correlated with ascending aortic compliance (microliter/mmHg) (r = -0.75). Magnetic resonance imaging is a noninvasive method for measurement of aortic flow wave velocity that is an important parameter in assessing arterial wall mechanics and blood flow dynamic.