Diagnostic Tests

[baby_sister]

I had CT scan without contrast done about 6 monthes ago. It said I had several hyperdense areas, maybe representing calcifications. Had a cytoscopy afterwards that showed suspicious areas that was sent for cytology, but I haven't heard yet. Still having persistant hematuria so had a CT done with contrast this time, and the findings were 1) scattered ill-defined hyperdense areas within the subcortical and corticomedullary regions of left kidney, and 2) hypodense lesions left kidney, too small to characterize. the hypodense areas are in the upper pole, lateral interpole, and anterior lower pole of left kidney. That is about the same position of the hyperdense areas on the Ct scan without contrast. My question in, do they turn from hyper dense before to hypodense after contrast? Is that something to do with attentuation? I would appreciate any info.

[IBPPMD]

Renal masses cannot be adequately characterized with non contrast imaging (CT and MRI alike). One must be able to assess if the lesion or lesions in question enhance with contrast (have blood flow within them). Enhancement with contrast tells us that the lesion is a solid lesion (tumor) not a cyst. Most solid renal lesion/tumors are renal cancers and are presumed to be cancer until proven othewise (removal or biopsy of the lesion followed by pathologic evaluation is the only way to make the definitive diagnosis).

A simple renal cyst appears hypodense on both non-contrast and contrast enhanced CT. These are benign and no further evaluation of a simple cyst is necessary. A hyperdense cyst is usually a simple cyst which has blood mixed in the normally clear fluid within the cyst. These hyperdense cysts have a minimal association of turning into cancer or anything worrisome. Most of us would recommend serial CT scans with or without contrast at 6 to 12 month interval for a few years to make sure they are stable before forgetting about them

Renal lesions (cysts and tumors) are very difficult to characterize when they are smaller then 1 cm. This usually results in the recommendation of follow-up imaging at 6 to 12 months intervals to confirm stability or until an definitive diagnosis can be made.