[Non-vascular retroperitoneal emergencies]

Acute renal disease, in the absence of trauma, consist of acute renal obstruction, renal infection or a combination of the two. The diagnosis of acute renal colic is usually performed with ultrasound or excretory urography whereas parenchymal involvement in renal infection is best demonstrated on computed tomography images. The aim of radiologic investigations is to look for complications in order to guide the treatment, particularly percutaneous procedures. Other less common acute renal diseases include renal vein thrombosis optimally analyzed with contrast injection to demonstrate renal function, and spontaneous renal hemorrhage, which implies careful renal assessment looking for a small tumor. Acute psoas compartment diseases include hematomas and abscesses. Computed tomography is the best diagnostic tool and the examination of choice for the follow-up lesions and to guide percutaneous drainage.