Learning objectives
1.
To demonstrate variable CT patterns of bowel wall thickening in acute abdomen.
2.
To categorize major differential diagnosis bywall atteunation,
thickness,
length,
contrast-enhancing pattern of bowel wall,
and perienteric change.
3.
To identify the main radiological features of bowel wall abnormalities in inflammation,
ischemia,
hemorrhage,
neoplasm and hypoalbuminemia-related condition of bowels.
Background
CT plays an important role in the evaluation of patients with acute abdomen in emergency department.
High-resolution imaging of gastrointestinal tract by helical CT or multidetector CT allows assessment of both mural abnormality and related extraluminal change.
Thickened bowel wall is often encountered by the radiologists in CT interpretation of acute abdomen.
Such an abnormal change of bowel wall may suggest gastrointestinal tract disorders,
but differential diagnosis is wide,
ranging from mild,
non-specific medical condition to life-threatening surgical condition.
Intriguing CT patterns of bowel wall...
Imaging findings OR Procedure details
CT Image of Normal Bowel Wall
When optimally distended,
normal bowel wall is barely visible at CT.
The thickness of small bowel and colon measures not greater than 1.5 mm and 2-3 mm,
respectively.
When the thickness of distended bowel is greater than 3 mm,
bowel wall thickening is defined.
After intravenous contrast material administration,
the visible wall usually manifests modest enhancement at CT.
The mean enhancement measures about 118-120 HU and 107-111 HU at arterial and portal phases,
respectively.
Normal perienteric fat should appear...
Conclusion
Wall thickening of short length,
asymmetric irregular thickness with abrupt shouldering,
and solid homogeneous or heterogeneous contrast enhancing pattern suggests intestinal neoplasm.
Wall thickening of long length,
concentric smooth thickness with long transition,
and target pattern of contrast enhancement favor non-neoplastic conditions.
Absence of mural contrast enhancement signifies bowel ischemia.
High-attenuated wall thickening on precontrast image indicates intramural hemorrhage.
Perienteric fat stranding is most prominent with severe inflammation,
ischemia and invasive malignancy.
Bloody ascites frequently relates to intramural hemorrhage or ischemia.
Analysis of the CT...
References
Wiesner W.et al.
CT of acute bowel ischemia.
Radiology.
226(3):635-50,
2003.
Xiong L et al.Frequency and CT patterns of bowel wall thickening proximal to cancer of the colon.
AJR.182(4):905-9,
2004.
Harisinghani MG.
et al.
Bowel wall fat halo sign in patients without intestinal disease.
AJR.
181(3):781-4,
2003.
Kirkpatrick ID et al.Gastrointestinal complications in the neutropenic patient: characterization and differentiation with abdominal CT.
Radiology.
226(3):668-74,
2003.
Macari M.
et al.
Intestinal ischemia versus intramural hemorrhage: CT evaluation.
AJR.
180(1):177-84,
2003
Kircher MF.
et al.
Frequency,
sensitivity,...
Personal Information
Jen-Dar Chen,
MD.
& MSc.
Chief of Department of Radiology,
Taipei City Hospital - Zhongxiao Branch,
Taipei,
Taiwan.
Consultant radiologist of Department of Radiology,
Taipei Veterans General Hospital,
Taipei,
Taiwan.
e-mail address:
[email protected]