IS Case 577: Acute appendicitis and ureterolithiasis with mild right hydroureter
Imaging Sciences URMC 2010
Publication Date: 2011-11-17
Patient is a 36-year-old male with eleven hours of 10/10 right lower quadrant pain. He also complained of nausea. History is significant for numerous instances of nephrolithiasis requiring lithotripsy and basket extraction. Physical exam was positive for tenderness at McBurney's point.
Appendicitis is caused by obstruction of the appendiceal lumen, leading to venous obstruction, ischemia, bacterial invasion, and finally necrosis. CT features of acute appendicitis include appendiceal thickness of 6 mm, thickened walls, surrounding fat stranding, proximal filling and distal inflammation, asymmetric cecal wall thickening, adenopathy at the mesoappendix, and calcified appendicolith (seen in 28-30% of all cases).
In acute ureteral obstruction, a stone is seen within the ureter, most commonly at the UVJ or at the UPJ. Stones larger than 6 mm have difficulty passing on their own. The tissue rim sign is a good way of spotting ureteral stone; this is when a circle of soft tissue is seen surrounding the stone. Findings that may be associated with an obstructive ureteral stone include perinephric or periureteral fat stranding, hydronephrosis, dilated ureter proximal to the obstruction.
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