ASSESSMENT OF MYOCARDIAL VIABILITY WITH TECHNETIUM-99M SESTAMIBI

锝-99mSestamibi和铊成像具有相似的准确性， 用于检测冠状动脉疾病（CAD），但是否 sestamibi提供了关于心肌活力的准确信息 在慢性CAD和左心室（LV）功能不全患者中， 尚未建立。 54例患者（49例男性，5例女性，年龄36-79岁）， 慢性CAD和LV功能障碍经历了应力重分布， 回注铊断层扫描和同一天静息-应力-司他米比 显像 在111个可逆的铊缺陷中，40个（36%）是 在静息应力sestamibi研究中确定为不可逆，而 63个不可逆的铊缺陷中只有3个（5%）被分类为 通过Sestamibi成像可逆转。 因此，关于 心肌缺损的可逆性之间的铊应激- 再分配-回注和同日静止-应力sestamibi研究 是75%。 33名患者的一个亚组也接受了正电子发射 使用F-18氟脱氧葡萄糖在静息时进行的断层扫描（PET）研究 口服葡萄糖负荷。 与54名患者的总体组相似， 铊和Sestamibi成像之间存在一致性， 76个区域中有57个（75%）缺陷可逆。 在剩下的19 (25%）不一致区域，所有19个区域均显示不可逆性 但通过铊成像是可逆的，并且代谢活跃 的PET。 然后，我们探索了改善sestamibi结果的方法。 首先，当19个不和谐的地区与不可逆转的sestamibi 根据缺陷的严重程度进一步分析缺陷，17 (89%）仅表现出轻度至中度的司他米比活性降低 (51至正常活性的85%），提示主要存活 心肌 第二，当一个额外的4小时重新分配的形象， 18例患者在静息时注射司他米比后获得， 16个（38%）静息-应力不可逆区 研究变得可逆，从而增加了 铊和溴代异氰尿酸研究达到82%。 因此，当临床问题 是一种心肌活力而不是运动引起的缺血， 对铊和溴化铋的研究在大多数国家提供了一致的信息。 异常区域

Technetium-99m sestamibi and thallium imaging have similar accuracy when used for detection of coronary artery disease (CAD), but whether sestamibi provides accurate information regarding myocardial viability in patients with chronic CAD and left ventricular (LV) dysfunction has not been established. Fifty-four patients (49M, 5F, ages 36-79) with chronic CAD and LV dysfunction underwent stress-redistribution- reinjection thallium tomography and same-day rest-stress sestamibi imaging. Of the 111 reversible thallium defects, 40 (36%) were determined to be irreversible on the rest-stress sestamibi study, while only 3 of 63 (5%) irreversible thallium defects were classified to be reversible by sestamibi imaging. Hence, the concordance regarding reversibility of myocardial defects between thallium stress- redistribution-reinjection and same day rest-stress sestamibi studies was 75%. A subgroup of 33 patients also underwent positron emission tomography (PET) studies with F-18 fluorodeoxyglucose at rest following an oral glucose load. Similar to the overall group of 54 patients, there was concordance between thallium and sestamibi imaging regarding defect reversibility in 57 of 76 (75%) regions. In the remaining 19 (25%) discordant regions, all 19 appeared irreversible by sestamibi imaging but were reversible by thallium imaging and metabolically active by PET. We then explored methods to improve the sestamibi results. First, when the 19 discordant regions with irreversible sestamibi defects were further analyzed according to the severity of defects, 17 (89%) demonstrated only mild-to-moderate reduction in sestamibi activity (51 to 85% of normal activity) suggestive of predominantly viable myocardium. Second, when an additional 4-hour redistribution image was acquired in 18 patients after the injection of sestamibi at rest, 6 of 16 (38%) discordant irreversible regions on the rest-stress sestamibi study became reversible, thereby increasing the concordance between thallium and sestamibi studies to 82%. Thus, when the clinical question is one of myocardial viability rather than exercise-induced ischemia, thallium and sestamibi studies provide concordant information in most abnormal regions.