1Clinical Laboratory, Kobe City Medical Center General Hospital, 2Gastroentelogy and Hepatology, Kobe City Medical Center General Hospital, 3Clinical Pathology, Kobe City Medical Center General Hospital
【Introduction】 Acute abdomen accounts for the large portion of gastrointestinal diseases, and gastrointestinal evaluation will become, therefore, a crucial point. The determination of early diagnosis and therapeutic strategy in acute abdomen often has a great influence on subsequent quality of life（QOL）；however, if neglected, acute abdomen may lead to fatal outcome. Ultrasonography is a technique to non-invasively observe a wide range of diagnostic field and is utilized as initial response to diagnosis of acute abdomen. However, because there are various problems which hinder this definitive diagnosis, it will be necessary to organize and recognize the usage of more effective ultrasonography. Here, we examine the usability of gastrointestinal evaluation in acute abdomen, while considering merits and demerits, along with diseases etc., which can be diagnosed only using ultrasonography. 【Merits and demerits of ultrasonography in acute abdomen】 Acute abdominal pain is caused by mechanical abnormalities, as well as functional abnormalities consequent to stimuli of the autonomic nervous system, such as gastrointestinal contraction, spasms, elongation, and distension. Merits of ultrasonography are to perform functional and dynamic evaluation of the gastrointestinal tract with high-resolution real-time ultrasonography and to evaluate changes in shape of gastrointestinal tract caused by compression etc. A Doppler is a unique ultrasound method to visualize the blood flow including angioarchitectonic images as well as velocity and direction of blood flow. Dynamic evaluation of blood flow including the degree of inflammation and ischemia is useful even in acute abdomen caused by gastrointestinal diseases. Because a Doppler can be conducted in the constricted area without preparation, as well as is simple and speedy, this will be the test which becomes the initial diagnostic test of choice. On the other hand, one of the demerits of ultrasonography is to be highly operator-dependent or device-dependent. Moreover, only the operator who performed ultrasonography can explain the images saved on a computer. Although ultrasonography can examine a wide range of diagnostic field, it is uncertain whether the ultrasonography can adequately cover all the diagnostic field because of the blind areas; therefore, there is a problem with objectivity and validity of ultrasound imaging. However, these demerits can be overcome, to some extent, by acquiring proficiency in systematic scanning procedures, diagnostic methods, etc. 【Conclusion】 Ultrasonography is essential for diagnosis of acute abdomen. Both morphological and functional diagnoses based on ultrasonography are thought to have a high enough ability to overwhelm other diagnostic methods in the gastrointestinal field. Therefore, ultrasonography is the test which becomes the initial diagnostic test of choice.