[Dose reduction in abdominal computed tomography]

[Vascular causes of clinically unclear acute abdomen]

CLINICAL ISSUE

Vascular abnormalities are a rare cause of an acute abdomen. They include arterial bleeding and ischemia, the latter being either in the arterial or venous system. The most common cause of an acute ischemic abdomen is acute mesenteric ischemia caused by a thromboembolic occlusion of the superior mesenteric artery, followed by thrombotic occlusion of the portal vein, the mesenteric vein as well as the hepatic veins and the suprahepatic part of the inferior vena cava. In the case of an acute abdomen due to internal bleeding, all abdominal arteries can be the source but most common are ruptures of aortic aneurysms and inflammatory-driven bleeding from the superior mesenteric artery.

PRACTICAL RECOMMENDATIONS

Due to the high mortality, vascular causes should be diagnosed as soon as possible. For this purpose, computed tomography (CT) has evolved into the preferred tool due to its high availability and speed. To differentiate various vascular causes of an acute abdomen, it is important to incorporate a CT protocol without contrast media as well as contrast-enhanced series in arterial and venous phases. Conventional angiography has been replaced by CT for the diagnosis of vascular pathologies causing an acute abdomen; however, it plays an increasing role in the treatment of these pathologies.

[Abdominal polytrauma and parenchymal organs]

CLINICAL/METHODOLOGICAL ISSUE

The acute radiological diagnostics of polytrauma patients has become an essential part of the interdisciplinary treatment in the emergency room. The incidence of polytrauma patients with an injury severity score (ISS) >16 is approximately 450 cases/million inhabitants/year in Europe. Injuries of the parenchymal organs are of utmost importance for the prognosis and treatment of these patients. The injury patterns are complex and a great deal of experience is necessary to be able to obtain the correct diagnosis within minutes. This review article deals with the radiological diagnostics and grading of the severity of injuries to the spleen, liver, pancreas and kidneys.

STANDARD RADIOLOGICAL METHODS

The use of ultrasound for the evaluation of polytraumatized patients will be discussed. The most important trauma-associated findings for the above mentioned organs using multidetector computed tomography (MDCT) will be described and illustrated by dedicated case findings.

METHODOLOGICAL INNOVATIONS

Ultrasound contrast agents can supply valuable, additional diagnostic information in the evaluation of polytraumatized patients. Computed tomography has become established as the most relevant imaging modality in severe trauma. Innovative organ-adapted and contrast application protocols improve the diagnostic performance of MDCT.

PRACTICAL RECOMMENDATIONS

The use of focused assessment sonography for trauma (FAST) scanning as a screening tool is in agreement with the other clinical disciplines of the trauma team. The use of MDCT is trauma-dependent and the classification of the severity of the different parenchymal organ injuries is ultimately decisive for further treatment and prognosis of trauma victims.