Sun K T, De Groof M, Yi J, Hansen H W, Chen K, Czernin J, Phelps M E, Schelbert H R
Department of Molecular and Medical Pharmacology, UCLA School of Medicine 90024-1735.
J Nucl Med. 1994 Dec;35(12):2031-40.
This study validates perfusion defect extent and severity as derived by PET polar maps in vivo against measurements derived from radiolabeled microspheres.
In seven open-chest dogs, either the left anterior descending (n = 11) or left circumflex coronary artery (n = 13) were ligated sequentially from distal to proximal. After each occlusion, gated PET images were acquired with 13N-ammonia (20 mCi) while radiolabeled microspheres were administered into the left atrium. The transaxial PET images were reoriented into left ventricular short-axis cuts, including the apex, and polar maps were generated from circumferential activity profiles. PET polar maps were then compared with polar maps derived from microspheres after normal databases for 13N-ammonia and for microspheres were established. Nitrogen-13 or microsphere activities of less than 1.5 s.d. below the mean were defined as hypoperfused.
The extent (percent of left ventricular mass) and mean severity of the hypoperfused myocardium in the postmortem microsphere measurements ranged from 3% to 69% and 3% to 58%, respectively. The estimated extent by summed PET and by microspheres correlated by y = 4.95 + 0.95x (r = 0.91, s.e.e. = 0.085, p < 0.001) and mean severity by y = 5.52 + 0.87x (r = 0.85, s.e.e. = 0.101, p < 0.001). The extent and severity were similar for summed and gated PET studies.
The current study validated a polar map approach that provides accurate, quantitative assessment of the extent and severity of myocardial perfusion defects in vivo. Gating did not yield an improved correlation between PET and microsphere measurements. Thus, ungated PET images can be used to assess accurately the extent and severity of perfusion defects.
本研究验证了正电子发射断层扫描（PET）极坐标图在体内得出的灌注缺损范围和严重程度与放射性微球测量结果的一致性。
在7只开胸犬中，依次从远端到近端结扎左前降支（n = 11）或左旋支冠状动脉（n = 13）。每次闭塞后，静脉注射13N-氨（20 mCi）并采集门控PET图像，同时将放射性微球注入左心房。将横断面PET图像重新定位为包括心尖的左心室短轴切面，并根据圆周活性曲线生成极坐标图。在建立13N-氨和微球的正常数据库后，将PET极坐标图与微球得出的极坐标图进行比较。低于平均值1.5个标准差以下的13N或微球活性被定义为灌注不足。
死后微球测量中灌注不足心肌的范围（左心室质量百分比）和平均严重程度分别为3%至69%和3%至58%。PET总和法与微球法估计的范围通过y = 4.95 + 0.95x相关（r = 0.91，标准误差 = 0.085，p < 0.001），平均严重程度通过y = 5.52 + 0.87x相关（r = 0.85，标准误差 = 0.101，p < 0.001）。PET总和法和门控法研究的范围和严重程度相似。
本研究验证了一种极坐标图方法，该方法可在体内对心肌灌注缺损的范围和严重程度进行准确、定量评估。门控并未改善PET与微球测量之间的相关性。因此，非门控PET图像可用于准确评估灌注缺损的范围和严重程度。
