Chung Maggie, Dubel Gregory J, Noto Richard B, Yoo Don C, Baird Grayson L, Prince Ethan A, Murphy Timothy P, Haaga Timothy L, Ahn Sun Ho
1 Department of Diagnostic Imaging, Warren Alpert Medical School of Brown University, 222 Richmond St, Providence, RI 02903.
2 Department of Diagnostic Imaging, Warren Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI.
AJR Am J Roentgenol. 2016 Jul;207(1):170-6. doi: 10.2214/AJR.15.15380. Epub 2016 Apr 21.
The objective of the study was to determine if time to positive (TTP), defined as the time from the start of (99m)Tc-labeled RBC scanning to the appearance of a radionuclide blush (considered to be a positive finding for acute lower gastrointestinal bleeding [LGIB]), and lag time (LT), defined as the time from the appearance of a radionuclide blush to the start of catheter angiography (CA), affected the yield of CA for the detection of acute LGIB.
TTP and LT were retrospectively evaluated in 120 patients who had positive findings for acute LGIB on (99m)Tc-labeled RBC scanning and subsequently underwent CA for the diagnosis and localization of gastrointestinal bleeding. Two nuclear medicine fellowship-trained radiologists independently reviewed the (99m)Tc-labeled RBC scans. Two fellowship-trained interventional radiologists independently reviewed the angiograms. All data were analyzed using SAS software.
When a TTP threshold of ≤ 9 minutes was used, the sensitivity, specificity, positive predictive value, and negative predictive value for a positive CA study were 92%, 35%, 27%, and 94%, respectively. In addition, the odds of detecting bleeding on CA increased 6.1-fold with a TTP of ≤ 9 minutes relative to a TTP of > 9 minutes (p = 0.020). A significant inverse relationship was found between LT and a positive CA study (p = 0.041).
TTP and LT impact the rate of positive CA studies. A TTP threshold of ≤ 9 minutes allows the detection of almost all patients who would benefit from CA for treatment and allows a reduction in unnecessary negative CA studies. The likelihood of positive findings on CA decreases with a delay in the performance of CA.
本研究的目的是确定阳性时间（TTP，定义为从开始进行（99m）锝标记红细胞扫描到放射性核素 blush 出现的时间，放射性核素 blush 被视为急性下消化道出血[LGIB]的阳性发现）和延迟时间（LT，定义为从放射性核素 blush 出现到开始进行导管血管造影[CA]的时间）是否会影响 CA 检测急性 LGIB 的阳性率。
对 120 例在（99m）锝标记红细胞扫描中发现急性 LGIB 阳性结果并随后接受 CA 以诊断和定位胃肠道出血的患者进行回顾性评估 TTP 和 LT。两名接受过核医学专科培训的放射科医生独立审查（99m）锝标记红细胞扫描图像。两名接受过专科培训的介入放射科医生独立审查血管造影片。所有数据均使用 SAS 软件进行分析。
当使用≤9 分钟的 TTP 阈值时，CA 检查阳性的敏感性、特异性、阳性预测值和阴性预测值分别为 92%、35%、27%和 94%。此外，与 TTP＞9 分钟相比，TTP≤9 分钟时在 CA 上检测到出血的几率增加了 6.1 倍（p = 0.020）。发现 LT 与 CA 检查阳性之间存在显著的负相关关系（p = 0.041）。
TTP 和 LT 会影响 CA 检查阳性率。≤9 分钟的 TTP 阈值能够检测出几乎所有将从 CA 治疗中获益的患者，并减少不必要的阴性 CA 检查。CA 检查阳性结果的可能性会随着 CA 检查执行的延迟而降低。
