Hong Yun, Presenter: Nothing to Disclose

Mengsu Zeng MD, PhD, Abstract Co-Author: Nothing to Disclose

Hang Jin PhD, Abstract Co-Author: Nothing to Disclose

Shan Yang, Abstract Co-Author: Nothing to Disclose

To use 3.0T cardiac MR for the detection of acute (6 hour)  and subacute (1 week) myocardial changing after coronary microembolization (CME) in swine.

CME was induced in 12 swines (CME group) by injection of 120,000 microspheres (42μm in diameter) into distal LAD through microcatheter and 10ml saline was injected in 2 swines (control group). Cardiac MR imaging was performed by using 3.0-T system before and repeated six hours and one week after CME. The MR sequences included: TrueFISP cine sequence with TGRAPPA (accelerated factor 3) for the measurement of cardiac function, TSE-T2WI with scanning mode BLADE for the detection of myocardial edema and TurboFLASH sequence for the discovery of myocardial microinfarction. Finally, all animals were sacrificed for pathologic analyses (NBT and HE).

 DSA showed normal before and after CME. In control group，no abnormalities were found at 6th hour and 1 week, and this 2 swines were correctly identified. In CME group, left ventricular ejection fraction (LVEF) decreased significantly from (64.77±5.75)% at baseline to (54.15±3.77)% at the 6th hour (P <0.05), and improved to (55.65±8.41)% one week later (P <0.05 vs baseline). Compared with baseline values, the left ventricular end diastolic volume (LVEDV) enlarged significantly at sub-acute stage after CME (baseline 39.27±7.35ml， 1 week 48.22±5.13ml, P <0.05). The left ventricular end systolic volume (LVESV) were 13.92±3.63ml, 20.02±4.20ml, 21.50±5.33ml at the three time points respectively and significant difference were found in both 6th hour vs baseline and 1 week vs baseline. In T2WI-TSE sequence, the myocardial hypersignal was only observed in 2 swines at 1 week. Myocardial delayed enhancements were found on LV short-axis section in all swines during acute stage. However, the delayed enhanced areas disappeared in 10 swines and only existed in 2 swines, which were consistent with NBT pathological findings.

CME caused significant decline in LVEF at 6th hour and improved slightly at 1 week. The LVEDV and LVESV were persistent enlarged. Myocardial delayed enhancement were found in all swines at 6th hour and disappeared or diminished one week later , which were consistent with NBT pathological findings.

3.0T cardiac MRI has potential to quantify the changes of cardiac function and to detect the microinfaction. Improved scanning technique is needed to detect the myocardial edema.

Yun, H, Zeng, M, Jin, H, Yang, S, 3.0 Tesla MR Imaging Characterization after Coronary Artery Microembolization in Swine.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11008647.html