Acute Abdomen: Rational Use of us, MDCT, and MRI

References .......................................................................... 28 Abstract The term ‘‘acute abdomen’’ defines a clinical syndrome characterized by the sudden onset of severe abdominal pain, requiring early medical or surgical treatment. The acute abdominal pain may be due to trauma or non-trauma diseases and it is a frequent condition in patients presenting to the hospital emergency department. Computed Tomography is universally considered the key imaging modality for the evaluation of severe trauma patients and patients with nontraumatic acute abdominal disease. In case of acute abdomen unenhanced CT scan is not performed routinely. The contrast enhanced CT study is performed with a two-phase protocol, in arterial and portal venous phases; in trauma patients excretory phase is done only in cases of suspected urinary track lesions (renal pelvis, ureter and bladder). Multiplanar reconstruction (MPRs) are useful for interpretation of abdominal diseases as they allow the scanned volume to be viewed in any arbitrary plane interactively determined by the viewer. These reconstructions are especially useful when tubular structures, such as vessels, ureters, and bowel, are followed. Maximum intensity projections (MIPs) are useful for CT angiography and CT urography. The reconstruction of volume rendered (VR) images is particularly helpful for visualization of complex anatomy and pathology of visceral vasculature and best delineates a tortuous course of vessels and small branches. V. Miele (&) Department of Emergency Radiology, S. Camillo Hospital, C.ne Gianicolense, 87, 00151 Rome, Italy e-mail: [email protected]