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.