Patients that are overhydrated, pregnant, or with a full-bladder may have mild hydronephrosis bilaterally without obstruction
Underhydrated patients may not have hydronephrosis on initial<unk>  scanning, despite obstruction<unk>  cysts can sometimes be mistaken for hydronephrosis
Cysts are typically single, circular, and arise in the periphery of the kidney
They can be multiple as in polycystic kidney disease
Cysts are typically single, circular, and arise in the periphery of the kidney
They can be multiple as in polycystic kidney disease
Bosniak I :Benign simple cyst with thin wall without septa, calcifications, or solid components.
Bosniak II: Benign cyst with a few thin septa, which may contain fine calcifications or a small segment of mildly thickened calcification.  Hyperdense cysts must be exophytic with at least 75% of its wall outside the kidney to allow for appropriate assessment of margins, otherwise they are categorized as IIF.
Bosniak IIF: Includes<unk>  cysts with multiple thin septa, a septum thicker than hairline, slightly thick wall, or with calcification, which may be thick. It also includes intrarenal cysts larger than 3 centimetres (1.2 inches). Category IIF cysts have a 5-10% risk of being kidney cancer, and therefore follow-up is recommended every 6 months.
Bosniak III: Indeterminate cystic masses with thickened irregular septa with enhancement. 50 % of these lesions are ultimately found to be malignant.
Bosniak IV: Malignant cystic masses with all the characteristics of category III lesions but also with enhancing soft tissue components on CT independent of but adjacent to the septa. 100 %of these lesions are malignant.
Bosniak IIF: Includes<unk>  cysts with multiple thin septa, a septum thicker than hairline, slightly thick wall, or with calcification, which may be thick. It also includes intrarenal cysts larger than 3 centimetres (1.2 inches). Category IIF cysts have a 5-10% risk of being kidney cancer, and therefore follow-up is recommended every 6 months.
Renal ultrasound
Bladder ultrasound
Bladder lavage
Urine analysis
Suprapubic bladder aspiration
Creatinine screening prior to IV contrast
Suprapubic catheter placement
Acute abdominal series