Renal cysts (benign and very common lesions) are readily detected and often also classified by ultrasound. Assuming good visualisation of the kidney, ultrasound is a sensitive tool to detect tumours of renal origin. Normal ultrasound findings in a well visualised kidney rule out presence of tumours. Real life is, however, a little more complex. Because there are some pit-falls in the interpretation (e.g. anatomic variants), additional CT examinations will be performed if there is any doubt.
If a true tumour or suspicious lesion is detected, CT will always be performed, as this modality gives an overview and can characterise tumours regarding their precise location, involvement of capsule or collecting system and invasiveness into neighbouring structures and vessels.
Small tumours in the renal pelvis are, as a rule, well detected by urography. So if presence of tumours is strongly suspected in spite of normal findings with ultrasound and CT, urography will be performed. On the other hand, small tumours in the parenchyma are not detected with urography.
Tumours in urinary bladder
Small tumours and polyps are often detected by ultrasound (only larger ones with urography)
If suspicious symptoms persist and diagnostic imaging is normal, cystoscopy is performed. This is an examination with a fibre-optic device done by a urologist which allows a direct visualisation of the mucous membrane.
Prostate tumours
Ordinary trans-abdominal ultrasound, CT, or urography can not rule out tumours.
In practice there are two imaging options: a special ultrasound procedure with a probe inside rectum, or with MRI. The former is widely used by urologists and some radiologists, and has quite a high sensitivity to detect small lesions. In addition the technique is very suitable for guidance of fine-needle biopsies. MRI is somewhat more experimental.