RT Journal Article SR Electronic T1 18F-FDG PET/CT imaging for myocardial “ischemic memory” in different degrees JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1532 OP 1532 VO 59 IS supplement 1 A1 Xuemei Wang A1 Guojian Zhang A1 Yulin He A1 Jianbo Li A1 Lei Liu YR 2018 UL http://jnm.snmjournals.org/content/59/supplement_1/1532.abstract AB 1532Objectives: According to compare the change of glucose metabolism and ischemic range on ischemic myocardial under two conditions of fasting and feeding by using Micro-PET/CT 18F-FDG imaging with the SD model of acute myocardial ischemia in different degrees. Methods: 100 male SD rats weighing 400 ± 50g. The model of acute myocardial ischemia was made by ligating the inferior one-third of left anterior descending coronary artery. According to different blood flow occlusion time, the SD model was randomly divided into mild ischemic group (ligation 10s, 30 rats), moderate ischemic group (ligation 10s, 30 rats) and the severe ischemic group (ligation 60s, 35 rats). First, we randomly selected 10 SD model from the severe ischemic group as fast-feed comparison group which underwent 18F-FDG Micro-PET / CT imaging after 24 hours twicely. the interval time was 6 hours. then, we calculated the volume of the ischemic (VOI) and the Standardized uptake value (SUVmean) to compare weather the scope of ischemic myocardium under two kinds of conditions were the same. The rest of three diffrent degree of ischemic group model rats were checked by 18F-FDG myocardial imaging at 24h, 48h, 72h and (96h) after modeling respectively. All models were performed ECG monitoring before and after each period of imaging, and then we calculated and compared the volume of the ischemic (VOI) and the Standardized uptake value (SUVmean) of each one. Results: 1. Fast-Feed comparison group: model rats showed a "focal" myocardial 18F-FDG uptake increased, the volume of myocardial imaging agent was 17.52 ± 1.14mm3, the similar difference was observed in the same part of the model rats with the "focal" myocardium 18F-FDG, and the defect volume of the myocardial imaging agent was 20.00 ± 2.85mm3 (difference = 2.48 ± 3.78, t = 2.074, p > 0.05), the difference was not statistically significant. The mean intake of SUVmean was 1.67 ± 0.31 and 1.13 ± 049(difference = 0.54 ± 0.80, t = 2.135, P> 0.05 ,which was not statistically significant). 2. The mild , moderate, severe three groups of mice 18F-FDG PET/CT myocardial metabolism imaging: (1) ischemic 10s group, 30s group, 60s group after24h modeling successfully, the defect volume of the imaging agent in the left ventricular wall was 8.31 ± 0.67mm3, 15.16 ± 0.65mm3 and 20.15 ± 2.48mm3, respectively. The corresponding standard uptake value SUVmean was 0.71 ± 0.12, 0.96 ± 0.12, 0.97 ± 0.12. The degree of myocardial ischemia was gradually increased with the severity of myocardial ischemia. (2)ischemic 10s group, 30s group, 60s group after modeling 48h successfully : The defect volume of the imaging agent in the left ventricular wall was 5.38±0.51 mm3, 5.05±1.34mm3, 6.03±1.14 mm3, respectively. The corresponding standard uptake value SUVmean was 2.04±0.21, 2.05±0.85, 2.26±0.81. (3)ischemic 10s group, 30s group, 60s group after modeling 72h successfully: For 10s group and 30s group, there has no abnormal imaging uptake of sparse area. By contrast, the defect volume of 60s group is 1.38±0.34 mm3. The corresponding standard uptake value of the three groups was 4.64±0.85,4.85±0.74,4.66±0.90 respectively. The difference was statistically significant. Conclusions: 1.18F-FDG Micro-PET / CT myocardial imaging can be used to detect the recent myocardial ischemia in the feed condition. 2. The time window of myocardial "ischemic memory" was different in various degree of myocardial ischemia. As to myocardial ischemia in mild-moderate degree , the time window of myocardial "ischemic memory" can be prolonged to 48 hours. For severe degree , the time window of myocardial "ischemic memory" can be prolonged to 72 hours. 3. The presence of "ischemic memory" is related to the severity of myocardial ischemia. With the severity of ischemic degree aggravating, the time window of myocardial "ischemic memory" is also prolonged. Key Words: Myocardial ischemia, 18 F-FDG Micro-PET/CT imaging, ischemic memory