Contrast‐enhanced 4D radial coronary artery imaging at 3.0 T within a single breath‐hold

Abstract

Coronary magnetic resonance angiography data are usually acquired during mid-diastole of each heartbeat to minimize cardiac motion related artifacts. The proper trigger delay time, which may vary widely among subjects, must be determined individually for each subject before data acquisition to achieve optimal image quality. These complications could be resolved by acquiring contiguous cardiac phase images through the cardiac cycle. In this study, we used a radial sampling technique to acquire 3D cine coronary artery images at 3 T within a single breath-hold. An extravascular, paramagnetic contrast agent was i.v. administered to improve the blood signal intensity. Relatively high temporal resolution and spatial resolution were achieved simultaneously with radial sampling, parallel data acquisition, and interleaved sliding window image reconstruction. Volunteer studies demonstrate the feasibility of this technique in acquiring 4D coronary artery images and the flexibility in postprocessing of 3D image sets. Magn Reson Med 54:470 -475, 2005.

MR Image-Based Geometric and Hemodynamic Investigation of the Right Coronary Artery with Dynamic Vessel Motion

“…43 However, in patients with fast heart rates, the end systolic pause may be longer and imaging would best be performed at this time. 50 Although 3D cine coronary angiography has been proposed using radial 3 and Cartesian 5 approaches, the temporal resolution achievable is limited and the rationale behind this approach has largely been to avoid the need for determining a subject-specific trigger time and acquisition window, and to enable averaging over those phases where motion is minimal to improve signal-to-noise ratio. Using a 111-148 ms acquisition window for example, Bi et al 3 found that visualization of the right coronary artery was adequate in just 4 out of 16 view-shared cardiac phases.…”

“…50 Although 3D cine coronary angiography has been proposed using radial 3 and Cartesian 5 approaches, the temporal resolution achievable is limited and the rationale behind this approach has largely been to avoid the need for determining a subject-specific trigger time and acquisition window, and to enable averaging over those phases where motion is minimal to improve signal-to-noise ratio. Using a 111-148 ms acquisition window for example, Bi et al 3 found that visualization of the right coronary artery was adequate in just 4 out of 16 view-shared cardiac phases. To image at multiple time-points throughout the cardiac cycle, including when there is rapid motion, requires a short acquisition window which would lead to a prohibitively long study duration with this technique.…”

Cardiac Magnetic Resonance at High Field: Promises and Problems

“…This whole-heart approach is feasible at 3T as it is at 1.5T using either breath holding (43,44) or free breathing navigator gated techniques (45). Although, the whole-heart technique at 3T has been shown to be useful for the assessment of coronary artery anomalies (45), its utilization for CAD evaluation has not yet been proven to be possible as it is shown at 1.5T (38, 39).…”

“…Similarly, black blood vessel wall imaging is feasible at 3T and is improved by using adiabatic IR preparatory pulse (22), however, the resolution limits and its application in CAD patients has not been exploited to date. The advantage of prolonged T1 time has also proven to beneficial for contrast enhanced CMRA at high magnetic field (43,44). Further exploitation of this prolonged T1 time can potentially be used for spin labeled CMRA (8).…”

Whole Heart Coronary Imaging with Flexible Acquisition Window and Trigger Delay

“…have proposed a segmented 3D radial stack-of-stars acquisition approach that generated four consecutive volumes at each temporal sub-window [12], combining these sub-images to improve image quality. Additionally, several other studies have explored coronary acquisition over multiple temporal phases using k-space segmented strategies [6,13] or high-resolution 3D cine approaches [14–17] with radial or spiral sampling patterns. In all of the aforementioned multiphase 3D volumetric imaging approaches, the temporal window resolution is defined as the duration of each equally spaced temporal phase, and is not inherently designed for retrospective processing of any desired temporal subset within the acquisition window.…”