Nontraumatic splenic emergencies: cross-sectional imaging findings and triage.

The spleen is commonly involved in a wide spectrum of hematologic, immunologic, neoplastic, infectious, and vascular systemic disorders. Sometimes overlooked on imaging studies outside the trauma setting, the spleen may harbor severe infections, and occasionally undergoes spontaneous bleeding or rupture. This pictorial essay reviews common and unusual causes of nontraumatic acute abnormalities primarily involving the spleen, and their cross-sectional imaging appearances. Emphasis is placed on multidetector computed tomography (MDCT) imaging, which represents the modality of choice to comprehensively assess acute splenic disorders including partial or complete infarctions, vascular diseases such as venous thrombosis, abscess collections, bleeding, and rupture. State-of-the-art magnetic resonance imaging represents a problem-solving technique. Borrowing from experience with grading abdominal trauma according to the traditional American Association for the Surgery of Trauma scale, spontaneous splenic injuries are confidently detected and characterized at MDCT. Furthermore, MDCT allows to identify or exclude coexistent perisplenic and intraperitoneal hemorrhage, presence and source of active bleeding, and contained vascular injury. Occasionally idiopathic, spontaneous splenic injuries should be suspected when acute abdominal manifestations and signs of hemodynamic compromise occur in a background of acute viral infections, endocarditis or sepsis, malaria, immune suppression, hematological disorders, malignancies, coagulopathy, or therapeutic anticoagulation. These uncommon yet life-threatening conditions require prompt diagnostic evaluation that allows correct triage between conservative, medical, interventional, and surgical treatment, and may obviate splenectomy. Finally, MDCT imaging allows differentiation of splenic rupture from other rare causes of spontaneous hemoperitoneum, and reliable follow-up of nonsurgically treated patients.