Imaging Pearls ❯ Vascular ❯ GI Bleeding
|
-- OR -- |
|
- 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.
Conclusions In patients requiring conventional angiography for GI bleeding, CT angiography results in a faster time to angi- ography 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.
Time to conventional angiography in gastrointestinal bleeding: CT angiography compared to tagged RBC scan
Hsu MJ et al.
Abdominal Radiol (in press ) 2019 - “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 inter- vention 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).”
Time to conventional angiography in gastrointestinal bleeding: CT angiography compared to tagged RBC scan
Hsu MJ et al.
Abdominal Radiol (in press ) 2019 - ”The results show that in the clinical setting of a patient presenting with GI bleeding requiring catheter-directed embolization, CTA reduces the time to angiography as compared to tagged RBC scanning. Furthermore, the overall time from the decision to order a radiologic study to catheter angiography is faster with CTA. Given the time from diagnostic study completion to angiography was not statistically significant between the two groups, it can be inferred that the limiting step was with diagnosis.”
Time to conventional angiography in gastrointestinal bleeding: CT angiography compared to tagged RBC scan
Hsu MJ et al.
Abdominal Radiol (in press ) 2019
- “Both CTA and RBC scintigraphy can be used to identify active bleeding in 38% of cases. However, the site of bleeding is localized with CTA in a significantly higher proportion of studies.”
Localizing Acute Lower Gastrointestinal Hemorrhage: CT Angiography Versus Tagged RBC Scintigraphy Feuerstein JD et al. AJR 2016; 207:578–584 - “In total, 45 CTA and 90 RBC scintigraphic examinations were performed during the study period. Seventeen (38%) CTA scans showed active gastrointestinal bleeding compared with 34 (38%) RBC scintigraphic scans (p = 1.000). However, the site of bleeding was accurately localized on 24 (53%) CTA scans. This proportion was significantly greater than the proportion localized on RBC scintigraphic scans (27 [30%]) (p = 0.008). There were no significant differences between the two groups in average hospital length of stay, blood transfusion requirement, incidence of acute kidney injury, or in-hospital mortality.”
Localizing Acute Lower Gastrointestinal Hemorrhage: CT Angiography Versus Tagged RBC Scintigraphy Feuerstein JD et al. AJR 2016; 207:578–584 - “The average time to complete an RBC scin- tigraphic examination was 3 hours 9 minutes after the order was placed. CTA examinations were completed an average of 1 hour 41 minutes after the initial order (p < 0.001). In the CTA group, 32 of 45 (71%) examinations were completed within 2 hours of initial order, com- pared with 31 of 90 (34%) RBC scintigraphic examinations (p < 0.001).”
Localizing Acute Lower Gastrointestinal Hemorrhage: CT Angiography Versus Tagged RBC Scintigraphy Feuerstein JD et al. AJR 2016; 207:578–584 - “Three-dimensional postprocessing is a critical step in the interpretation of lower extremity CTA. Maximum intensity projections (MIPs), oblique or
curved multiplanar reformats, 3-D VR images, and shaded surface displays can be used to augment analysis of the reconstructed cross-sectional axial images. Curved multiplanar reformats, which use the central axis of a vessel (also known as the centerline) to flatten and project the entire course of a vessel in a single plane, are particularly useful for evaluating vascular patency.”
Computed Tomography Angiography of the Lower Extremities. Cook TS. Radiol Clin North Am. 2016 Jan;54(1):115-30
- “Although CT enterography has limited sensitivity (55.2%; 16 of 29 patients) in identifying the source of obscure gastrointestinal bleeding, positive CT enterography findings can reliably indicate the true cause of of obscure GI bleeding with a high positive predictive value (100%; 16 of 16 patients).”
Obscure Gastrointestinal Bleeding: Diagnostic Performance of Multidetector CT Enterography
Lee SS et al.
Radiology 2011; 259:739-748 - “ CT enterography has a potential role in the evaluation of obscure gastrointestinal bleeding. Despite the limited sensitivity of CT enterography, positive CT enterographic findings can reliably indicate the true source of obscure gastrointestinal bleeding. CT enterography is particularly effective in helping identify the source of bleeding in patients with a history of massive bleeding.”
Obscure Gastrointestinal Bleeding: Diagnostic Performance of Multidetector CT Enterogrphy
Lee SS et al.
Radiology 2011; 259:739-748