Time to conventional angiography in gastrointestinal bleeding: CT angiography compared to tagged RBC scan

Abdom Radiol (NY). 2020 Feb;45(2):307-311. doi: 10.1007/s00261-019-02151-8.


Purpose: To compare CT angiography (CTA) and tagged red blood cell (RBC) scan as a function of time from these initial imaging studies to subsequent conventional angiography and catheter-directed embolization in patients with gastrointestinal (GI) bleeding.

Methods: An IRB-approved retrospective study was conducted of 35 consecutive patients diagnosed with GI bleeding that received angiography for planned catheter-directed embolization. Of these patients, 20 were diagnosed with bleeding using a tagged RBC scan, whereas 15 were diagnosed using CTA. The lengths of time between diagnostic study order to study completion, diagnostic study completion to angiography, and total time from diagnostic study order to angiography were calculated. The results of both groups were compared using a t test with p value of < 0.05 considered statistically significant.

Results: The mean time from diagnostic study order to study completion was 3 h and 4 min for the CTA group and 5 h and 1 min for the tagged RBC scan group (p value = 0.0001). There was no statistically significant difference between the time to angiography after completion of the preceding diagnostic study. The total mean time from diagnostic study order to intervention was 6 h and 8 min for the CTA group and 9 h and 29 min for the tagged RBC scan group, a statistically significant difference (p value = 0.028).

Conclusions: In patients requiring conventional angiography for GI bleeding, CT angiography results in a faster time to angiography than tagged RBC scan, which appears to be due to the longer duration required to complete the tagged RBC scan. Decreasing time to angiography is vital, as GI bleeding can be fatal and earlier diagnosis and intervention has the potential to reduce morbidity and mortality, while also increasing sensitivity of angiography. These findings may assist ordering clinicians in deciding on the appropriate diagnostic study.

Keywords: CT angiography; Conventional angiography; Embolization; Gastrointestinal GI bleeding; Interventional radiology.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Angiography / methods*
  • Computed Tomography Angiography
  • Embolization, Therapeutic
  • Erythrocytes
  • Female
  • Gastrointestinal Hemorrhage / diagnostic imaging*
  • Gastrointestinal Hemorrhage / therapy
  • Humans
  • Male
  • Middle Aged
  • Radiographic Image Interpretation, Computer-Assisted
  • Radiopharmaceuticals
  • Retrospective Studies


  • Radiopharmaceuticals