CASE 16186 Published on 01.11.2018
0

Bowel angioedema associated with iodinated contrast media

Section

Abdominal imaging

Case Type

Clinical Cases

Authors

Elie Lteif, Abdallah Noufaily, Carmen Adem.

Saint George Hospital University Medical Center ; Rmeil 1100 Beirut, Lebanon;
Email:
- elilteif@gmail.com
- noufaily@gmail.com
- cpadem@stgeorgehospital.org
Connected authors
Elie Lteif LEBANON
Patient

45 years, male

Categories
Area of Interest Abdomen, Gastrointestinal tract ; Imaging Technique CT-Angiography, CT
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Clinical History
A 45 year-old gentleman presented to the emergency department for acute abdominal pain, hypertension and microscopic hematuria. Patient had a right partial nephrectomy as a past surgical history. He was referred to the radiology department for a multi-phasic enhanced abdomino-pelvis CT examination.
Imaging Findings
After a conventional plain CT scan to rule out any obstructing urinary calculus, a totalof 85 mL non-ionic iodinated contrast media was administered intravenously using an autoinjector at a rate of 3 mL/s. Arterial and venous sequences were obtained, as well. The abdominal discomfort had slightly increased during the portal phase when the patient had an episode of vomiting. No skin rash or any respiratory symptoms were noted.

The bowel wall was normal on the non-enhanced and arterial phase images and the surrounding fat was clear. However, on venous phase sequences, there was a circumferential wall thickening along the proximal small bowel, mainly the duodenum.
No evidence of superior mesenteric artery ischemia or vein thrombosis were noted. No ascites or collection was seen. No enlarged lymph nodes or fat stranding was noted.

Patient's symptoms had resolved by the following day.
Discussion
Bowel wall thickness is usually well detected on CT scan that help to differentiate the underlying pathology related to several causes[1].Our patient presented for an acute abdominal pain with hypertension. He had also one episode of vomiting during the CT examination, precisely at the end of the venous protocol. No oral contrast or fluid were administered.
The bowel wall was normal on non-enhanced and on arterial images. However, a circumferential proximal bowel wall thickness was noted on portal phase sequences, thought to be the cause of vomiting at the end of scanning. The patient recovered without special treatment and the edema resolved without any intervention. Follow up examination and the gastroscopy show no intestinal abnormality.
A rapid change in bowel wall thickness may be an exclusive characteristic of an anaphylactic reaction post intravenous iodinated contrast[2, 4]. In our case, the bowel wall thickening appeared only on the venous phase about 1 min after administration of intravenous contrast.
No vascular engorgement, exudation, fat stranding or lymphadenopathy around the thickened bowel segment was noted, which eliminate other possible underlying abnormalities[2, 3].
The CM-induced bowel anaphylactic angioedema occurred less frequently than pruritus and urticaria[3, 5]. It is underestimated and could be missed on non-portal phase CT-scan[6, 7]. In addition, even without associated CT findings around the bowel wall, it may be misdiagnosed as other pathology specially if only the portal phase protocol is obtained [8, 9].
The underlying etiology and the relationship between the iodine concentration and the anaphylactic angioedema are not fully elucidated[7, 8]. However, according to the literature, several cases of induced bowel wall angioedema were noted at a lower concentration of iodinated CM[2].The transient anaphylactic small bowel angioedema and the non-allergic CM-induced hypersensitive immediate reactions share allegedly the same underlying process [5-8].
Most reported cases occurred mainly in the small intestine, mainly in its proximal segment.
The greater vessel supply of the small intestine in comparison to the remaining bowel could be the reason [8, 9].
A transient anaphylactic small bowel angioedema is well diagnosed on three-phase CT protocol[7].

A written informed patient consent for publication has been obtained.
Differential Diagnosis List
Duodenal angioedema post iodinated contrast media administration.
Duodenal wall inflammation
Duodenal cancer
Final Diagnosis
Duodenal angioedema post iodinated contrast media administration.
Case information
URL: https://eurorad.org/case/16186
DOI: 10.1594/EURORAD/CASE.16186
ISSN: 1563-4086
License

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

Figure 1

Axial slice of a non-enhanced CT scan of the abdomen

Axial slice of a non-enhanced CT scan of the abdomen
Axial slice of a non-enhanced CT scan of the upper abdomen shows normal bowel wall thickness. The remaining visualized organs are unremarkable, given the technique.
Figure 2

Arterial phase Axial CT-scan of the upper abdomen

Arterial phase Axial CT-scan of the upper abdomen
Axial slice of the arterial phase of the upper abdomen shows normal bowel wall thickness.The remaining visualized organs are unremarkable.
Figure 3

Coronal slice of a no-enhanced CT scan of the abdomen

Coronal slice of a no-enhanced CT scan of the abdomen
Coronal image of the arterial phase of the upper abdomen shows normal bowel wall thickness. A right renal cyst and a calculus in the left lower collecting are noted.
Figure 4

Coronal CT-scan slice of the portal phase of the abdomen

Coronal CT-scan slice of the portal phase of the abdomen
Coronal slice of the portal phase shows a thickened duodenal wall with significant narrowing of its lumen.
Figure 5

Axial CT-scan slice of the portal phase of the abdomen

Axial CT-scan slice of the portal phase of the abdomen
Lower image of the portal phase shows a thickened duodenal wall with significant narrowing of the lumen.
Axial CT-scan slice of the portal phase of the abdomen
Portal phase axial slice shows a thickened duodenal wall with significant narrowing of the lumen. A right renal cyst and a calculus in the left lower collecting are noted.