Detailed analysis of myocardial motion in volunteers and patients using high‐temporal‐resolution MR tissue phase mapping

Abstract

Purpose: To detect and investigate details in left ventricular (LV) motion patterns with a temporal resolution comparable to that of echocardiography. Material and Methods:To assess global and regional myocardial motion in high temporal detail, respiratory-gated MR phase-contrast measurements with three-directional velocity encoding (venc) were performed in 12 healthy volunteers and two patients with LV hypertrophy in basal, midventricular, and apical locations of the LV with a temporal resolution of 13.8 msec. Results:The volunteer data revealed details in LV motion patterns that were known only from echocardiography. For all volunteers, characteristic myocardial motion patterns, such as triphasic global diastolic expansion, could be detected with high accuracy. One volunteer underwent an additional echocardiographic measurement in order to corroborate the complex motion features as measured by MRI. Patient examinations revealed substantial changes in diastolic function compared to motion patterns in healthy volunteers. Conclusion:The proposed high-temporal-resolution velocitymapping technique provides previously undetectable information on LV performance, and is highly promising for the detection of local and global motion abnormalities in patients with disturbed LV performance, such as diastolic dysfunction.

Magnetic resonance tissue phase mapping: Analysis of age‐related and pathologically altered left ventricular radial and long‐axis dyssynchrony

“…A software tool programmed in MatLab (MathWorks, Natick, MA) was used for manual segmentation of the left ventricular endo-and epicardial contours and further data analysis (12,14,15). The measured threedirectional myocardial velocities were transformed into radial (v radial ), circumferential, and long-axis (v long-axis ) motion components.…”

“…Three short axis slices (basal, mid-ventricular, apical) were acquired using a black blood prepared time-resolved (CINE) gradient echo sequence with three-directional motion encoding (velocity sensitivity ¼ 15 cm/s in-plane, 25 cm/s through-plane). Data were acquired during free breathing (dual navigator gating of the lung-liver interface), view sharing, and segmental velocity encoding to assess myocardial velocities with a temporal resolution of 13.8 msec (12,13). Further imaging parameters were as follows: TE ¼ 5.0 msec, TR ¼ 6.9 msec, flip angle ¼ 15 , in-plane spatial resolution ¼ 1.3 Â 2.6 mm 2 , slice thickness ¼ 8 mm.…”

Some Applications of Magnetic Resonance Imaging in Fluid Mechanics: Complex Flows and Complex Fluids

“…This application is still in a research phase but may evolve into a useful tool in the diagnosis and treatment of coronary artery disease. By applying velocity gradients in three directions, one can image 3D contraction patterns of the heart muscle, allowing the isolation of defective regions ( Jung et al 2006). Flow measurements in the great arteries facilitate the assessment of pulse wave velocity, a measure of arterial elasticity, which is of clinical importance in heart failure and degenerative vascular disease (Nollen et al 2004).…”

Details of left ventricular radial wall motion supporting the ventricular theory of the third heart sound obtained by cardiac MR

“…5 The purpose of this study was to obtain new details of global and regional radial wall motion of the left ventricle using the cardiac MR high temporal resolution myocardial velocity-encoding technique. 6,7 Considering recent interest in myocardial multilayer measurements, which provide more layer-specific information about the functional state of the myocardium at different levels, [8][9][10][11][12][13] separate calculations of all myocardial velocities and their corresponding peak times for the inner (endocardial), middle (transmural) and outer (epicardial) layers of the LV wall were performed.…”

“…Pilot images, followed by horizontal and vertical long axis cine images, were acquired using a steady-state free precession pulse sequence. Cine images for navigator-gated high temporal resolution phase contrast velocity mapping were acquired using a black blood segmented k-space spoiled gradient echo sequence 6,7 with a temporal resolution of 13.8 ms (repetition time 5 13.8 ms, echo time 5 5.0 ms, flip angle 5 15°, bandwidth 5 650 Hz per pixel, field of view 5 400 3 300 mm and matrix 5 256 3 96).…”