<prompt> Answer this question truthfullyWhat is the role of CT in diagnosing hydronephrosis?  <response>: <reason> Abdominal CT scan may be helpful in the diagnosis of hydronephrosis. Findings on CT scan suggestive of hydronephrosis include: Stone size if hydronephrosis is due to kidney stones Papillary necrosis Dilation of the proximal ureter Dilatation of the collecting system Site of obstruction 