P2670 - CT Scans in Crohn's Disease Patients Presenting to the Emergency Department

Firrah Saeed, MD¹, Neal Dharmadhikari, MD², Joshua Tanzer, PhD³, Grayson Baird, PhD¹, David J. Grand, MD¹, Jonathan Movson, MD⁴, Samir A. Shah, MD^1
1Warren Alpert Medical School of Brown University, Providence, RI; ²Boston Medical Center, Boston, MA; ³Brown University, Providence, RI; ⁴Rhode Island Hospital, Providence, RI

Introduction: Crohn’s Disease (CD) patients are often subject to repeat computed tomography (CT) imaging upon presentation to the emergency department (ED). Due to early age of diagnosis and increase in ED visits, they are exposed to significant radiation posing long term increased risk of malignancy. In this retrospective study, we aim to break down the rate of urgent findings on CT including obstruction, perforation, abscess, or other non-CD related acute findings (OPAN) in relation to imaged features of the colon.

Methods: 660 previously diagnosed CD patients from 4 gastroenterology practices who presented to 3 hospitals between 4/15/2015 and 12/31/2018 were identified. A radiology database search generated 1778 CT scans performed at these ED encounters. Data was collected on presence of OPAN findings. Generalized mixed effects modeling was used to compare probabilities of each OPAN finding among patients with strictures, fistulas, and thickening. The relationship to the number of scans a patient received was considered.

Results: The sample was mainly male (71.87%) with mean age 50, and standard deviation 18. Figure 1 plots the skewed distribution of CT scans (skew=3.30). 46% received only 1 scan, 3% received between 2 to 4 scans, and 51% received more than 5 scans; the highest was 24 scans for 1 patient. 28.5% of scans reviewed demonstrated positive OPAN findings. Differences by number of scans were only significant among patients with obstruction (p=0.0299); patients with many scans were less likely to have obstruction (12% versus 19%). Patients with strictures were more likely to have obstruction (31% versus 8%, p< 0.001) and less likely to have abscesses (13% versus 4%, p< 0.0001). Conversely, patients with fistulizing disease were more likely to have abscesses (13% versus 4%, p< 0.0001) and less likely to have obstruction (13% versus 20%, p=0.0413).

Discussion: Radiation exposure in CD patients has been reported to be higher than that of the general population, owing to multiple CT scans often performed acutely in the ED. Our study illustrates the phenomenon of repeat imaging, but it is yet unclear if this increase in imaging confers an increase yield of urgent findings that may alter clinical management. Further investigation is necessary to identify factors such as laboratory markers and biologic agent use that may positively or negatively predict presence of OPAN findings, thus allowing us to create a prospective algorithm to help providers maximize diagnostic utility and minimize radiation.


Figure: Figure 1. Distribution of CT Scans


Disclosures:
Firrah Saeed indicated no relevant financial relationships.
Neal Dharmadhikari indicated no relevant financial relationships.
Joshua Tanzer indicated no relevant financial relationships.
Grayson Baird indicated no relevant financial relationships.
David Grand indicated no relevant financial relationships.
Jonathan Movson indicated no relevant financial relationships.
Samir Shah indicated no relevant financial relationships.


Firrah Saeed, MD¹, Neal Dharmadhikari, MD², Joshua Tanzer, PhD³, Grayson Baird, PhD¹, David J. Grand, MD¹, Jonathan Movson, MD⁴, Samir A. Shah, MD¹. P2670 - CT Scans in Crohn's Disease Patients Presenting to the Emergency Department, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.