Currie Geoffrey M, Towers Philip A, Wheat Janelle M
School of Clinical Sciences, Charles Sturt University, Wagga Wagga, New South Wales, Australia.
J Nucl Med Technol. 2006 Sep;34(3):160-8.
Acute lower gastrointestinal tract hemorrhage (LGIH) has significant morbidity and mortality outcomes. Although several causes of LGIH can be life threatening, most can be effectively treated; therefore, early detection and accurate localization of bleeding sites are critical for successful patient management.
This study was a phantom experimental study with a repeated-measures design. The minimum detectable bleeding rate, the minimum detectable bleed volume, the sensitivity for detection, and the time required for detection were determined and compared for conventional scintigraphy (CS) and 3 experimental techniques: reference subtraction scintigraphy (RSS), sequential subtraction scintigraphy (SSS), and alternate sequential subtraction scintigraphy (ASSS).
The minimum detectable bleeding rates within the first hour were 0.05 mL.min-1 for CS and RSS, 0.1 mL.min-1 for ASSS, and 0.5 mL.min-1 for SSS. This study demonstrated minimum detectable bleed volumes of 2.2 mL for CS, 2.3 mL for RSS, 5 mL for ASSS, and 5 mL for SSS stratified to a "definitely present" certainty. No statistically significant difference was noted in the mean time to detection between CS and the subtraction techniques. Receiver-operating-characteristic analysis indicated that combining CS and RSS improved test performance and increased overall sensitivity to 75% from 68.3% for CS and 71.7% for RSS.
Supplementing conventional datasets with RSS and ASSS may provide a useful tool that combines the advantages offered for lesion detectability by a high-contrast 99mTc-sulfur colloid study with the window of opportunity offered by 99mTc-labeled red blood cell scanning.
急性下消化道出血（LGIH）具有显著的发病率和死亡率结局。尽管LGIH的几种病因可能危及生命，但大多数可以得到有效治疗；因此，早期发现和准确确定出血部位对于患者的成功管理至关重要。
本研究是一项采用重复测量设计的体模实验研究。确定并比较了传统闪烁扫描（CS）和3种实验技术：参考减法闪烁扫描（RSS）、序贯减法闪烁扫描（SSS）和交替序贯减法闪烁扫描（ASSS）的最小可检测出血率、最小可检测出血量、检测灵敏度以及检测所需时间。
第1小时内的最小可检测出血率，CS和RSS为0.05 mL·min-1，ASSS为0.1 mL·min-1，SSS为0.5 mL·min-1。本研究表明，分层为“肯定存在”确定性时，CS的最小可检测出血量为2.2 mL，RSS为2.3 mL，ASSS为5 mL，SSS为5 mL。CS与减法技术之间在平均检测时间上未观察到统计学显著差异。受试者操作特征分析表明，将CS和RSS相结合可提高检测性能，总体灵敏度从CS的68.3%和RSS的71.7%提高到75%。
用RSS和ASSS补充传统数据集可能提供一种有用的工具，该工具结合了高对比度99mTc-硫胶体研究在病变可检测性方面提供的优势以及99mTc标记红细胞扫描提供的机会窗口。
