氮-13-氨和氧-15-水对左心室缺血性功能障碍时绝对心肌灌注的评估

Nitrogen-13-ammonia and oxygen-15-water estimates of absolute myocardial perfusion in left ventricular ischemic dysfunction.

作者信息

Gerber B L, Melin J A, Bol A, Labar D, Cogneau M, Michel C, Vanoverschelde J L

机构信息

Division of Cardiology, University of Louvain Medical School, Brussels, Belgium.

出版信息

J Nucl Med. 1998 Oct;39(10):1655-62.

PMID:9776263

Abstract

UNLABELLED

Measurements of resting myocardial blood flow (MBF) in patients with chronic left ventricular ischemic dysfunction by 15O-water with 13N-ammonia and PET have yielded conflicting results. The aim of this study was to perform a head-to-head comparison of both tracers in the same patient population and to answer the question of whether distinctive tracer properties account for differences in estimates of MBF in chronically dysfunctional myocardium by both tracers.

METHODS

A total of 30 patients with chronic dysfunction of the anterior myocardial wall due to significant left anterior descending coronary artery disease underwent PET measurements of absolute MBF in the anterior wall by use of 15O-water and 13N-ammonia before coronary revascularization by either coronary artery bypass graft (n = 24) or percutaneous transluminal coronary angioplasty (n = 6). Improvement of regional contractile function was assessed by two-dimensional echocardiography at a mean of 7.5 +/- 2.1 mo after revascularization. As judged from the changes in anterior myocardial wall motion after revascularization, patients were considered to have either reversibly (n = 16) or persistently (n = 14) dysfunctional myocardium. Estimates of MBF by 15O-water and 13N-ammonia, obtained in every patient before revascularization, were compared among the two patient groups by use of previously validated methods.

RESULTS

With 13N-ammonia, resting regional MBF was significantly higher in reversibly as opposed to persistently dysfunctional segments [84 +/- 8 versus 48 +/- 6 ml (min x 100 g)(-1), mean +/- s.e.m., p < 0.01]. By contrast, no such difference was found when using 15O-water to measure MBF [74 +/- 6 versus 86 +/- 9 ml (min x 100 g)(-1), p = ns]. This was mainly due to the fact that the perfusable tissue fraction (PTF), a fitted parameter of the 15O-water model, was significantly higher in reversibly as opposed to persistently dysfunctional segments (0.63 +/- 0.03 versus 0.50 +/- 0.03, p < 0.05). As a consequence, the 15O-water perfusable tissue index (PTI), which is the ratio of the PTF to the anatomical tissue fraction, was greater in reversibly dysfunctional as opposed to persistently dysfunctional segments (1.07 +/- 0.07 versus 0.79 +/- 0.05, p < 0.01).

CONCLUSION

This study demonstrates significant differences in MBF estimates between 15O-water and 13N-ammonia in chronically dysfunctional ischemic myocardium. Our results indicate that the 15O-water method yields higher absolute MBF values than the 13N-ammonia approach. Our results also support the use of PTI as a marker of myocardial tissue viability.

摘要

未标记

采用(^{15}O) - 水和(^{13}N) - 氨及正电子发射断层扫描（PET）测量慢性左心室缺血性功能障碍患者静息心肌血流量（MBF），结果相互矛盾。本研究的目的是在同一患者群体中对这两种示踪剂进行直接比较，并回答两种示踪剂特性差异是否导致两者对慢性功能障碍心肌MBF估计值不同的问题。

方法

共有30例因左前降支冠状动脉严重病变导致前壁心肌慢性功能障碍的患者，在冠状动脉搭桥术（(n = 24)）或经皮冠状动脉腔内血管成形术（(n = 6)）进行冠状动脉血运重建术前，使用(^{15}O) - 水和(^{13}N) - 氨对前壁进行PET测量绝对MBF。血运重建术后平均(7.5±2.1)个月，通过二维超声心动图评估区域收缩功能的改善情况。根据血运重建术后前壁心肌运动变化判断，患者被认为有可逆性（(n = 16)）或持续性（(n = 14)）功能障碍心肌。使用先前验证的方法，比较两组患者在血运重建术前每位患者用(^{15}O) - 水和(^{13}N) - 氨测得的MBF估计值。

结果

使用(^{13}N) - 氨时，可逆性功能障碍节段的静息区域MBF显著高于持续性功能障碍节段([84±8)对比(48±6) (ml(min×100g)^{-1})，平均值±标准误，(p < 0.01])。相比之下，使用(^{15}O) - 水测量MBF时未发现此类差异([74±6)对比(86±9) (ml(min×100g)^{-1})，(p =无统计学意义])。这主要是因为(^{15}O) - 水模型的拟合参数灌注组织分数（PTF）在可逆性功能障碍节段显著高于持续性功能障碍节段((0.63±0.03)对比(0.50±0.03)，(p < 0.05))。因此，作为PTF与解剖组织分数之比的(^{15}O) - 水灌注组织指数（PTI）在可逆性功能障碍节段大于持续性功能障碍节段((1.07±0.07)对比(0.79±0.05)，(p < 0.01))。