MANABE Noriaki1, HATA Jiro1, KAWAI Ryosuke1, IMAMURA Hiroshi1, HARUMA Ken2
Noriaki MANABE1, Jiro HATA1, Ryosuke KAWAI1, Hiroshi IMAMURA1, Ken HARUMA2
1Division of Endoscopy and Ultrasonography, Department of Clinical Pathology and Laboratory Medicine, Kawasaki Medical School, 2Department of General Internal Medicine 2, Kawasaki Medical School Kawasaki Hospital
Abdominal pain is a common symptom in the outpatient setting and is challenging to diagnose. Imaging studies will be required because final diagnosis is often not able to be made without any imaging studies especially in patients with acute abdomen. Utilization of computed tomography（CT）for evaluation of the acute abdomen continues to increase. However, CT examination may prove to be untenable due to the massive expansion of medical radiation exposure and health care costs. Recent several studies showed that both ultrasonography（US）and CT can reliably detect common diagnoses causing acute abdominal pain. The impression that US has a questionable role in bowel assessment is related to the operator-dependent nature of the modality as well as the technical challenges of performing bowel US. It has already been well-known that US has various benefits such as its relatively low cost, less-invasiveness, real time observation and absence of radiation exposure. Furthermore, with recent technological advances including contrast-enhanced ultrasound, the potential ability of US for gastrointestinal diseases has been gradually recognized for decades. The US findings related to bowel pathology in the acute abdomen is considered to be divided into four broad categories: bowel wall thickening（Fig. 1）, bowel obstruction（Fig. 2）, bowel ischemia and bowel perforation（Fig. 3，4）. Easiness of detection of these four categories of bowel pathology, purposely or unexpectedly, warrants the observation of bowel loops during the US examination for patients with acute abdomen. US can reveal a primary causes and plays a definitive role in making a diagnosis of acute abdomen. For all of these reasons, the US is considered to be the first line modality for acute abdomen. This lecture will focus on the pathologic sonographic appearances of bowel in four categories, with an emphasis on diagnostic utility of US examination.