Written by Graham Van Schaik
In patients with a gastrointestinal bleed (GIB), CT imaging was more often diagnostic when the specific indication (GIB) was listed within the requisition order and multiphase studies were ordered.
Why does this matter?
While CT imaging is not always diagnostic (or necessary) in patients presenting for GIB, optimized imaging techniques (i.e. multiphase CT) in undifferentiated bleeds identify culprit lesions more often than single phase alone. Does it matter if the indication ‘GIB’ is listed on the CT order?
I might be going through a phase…
This was an observational cohort study of adult ED patients presenting to a single academic ED between 5/5/2018 to 6/1/2020 and included patients with ICD-10 codes related to a GIB. CT reports from these patients were reviewed for indications, exam type, and findings and were considered “positive” if the study identified active bleeding, recent bleeding, or a suspected etiology for GIB.
943 patients had GIB; 312 (33%) had CT scans ordered. At this ED, CT protocols (including unenhanced, single portal venous phase, dual phase, dual phase with delays, or triple phase) are determined by a reviewing radiologist based on the indication listed. Of those 312 patients with CT, 200 (64.1%) had a single portal venous phase and 90 (28.9%) were multiphase. CT identified active bleeding in 4.2% and intraluminal blood in 2.9%. They also found that patients with GIB indications listed on requisition orders were more likely to undergo a multiphase study compared to those without GIB (43.0% vs. 8.5%). To complement this, they found that patients undergoing multiphase studies were more likely to have a source of GIB identified compared to single-phase: 18.9% vs 1.5%, OR 15.3 (95%CI 4.4 to 53.7).
Bottom Line: While the external validity of this study may be limited (since not all academic shops have radiologists selecting CT phases), the work does suggest two things:
- We really should seek to be specific in our study indications.
- If ordering a CT for a suspected GIB, consider a multiphase study first (barring contraindications).
Editor’s note: I don’t have too many phone numbers memorized, but I could recite the ED reading room number right now. Our radiology friends are smart. When in doubt, call and ask what would help them see the pathology best. ~Clay Smith
Importance of communication of CT indication for imaging yield in patients with gastrointestinal bleed. Am J Emerg Med. 2022 Dec 5;64:101-105. doi: 10.1016/j.ajem.2022.12.003. Online ahead of print.