Typically on MRI, the prostate has a uniform (homogenous) appearance; however, sometimes the prostate looks patchy (heterogeneous). The causes of a heterogeneous area can vary, including past inflammation or infection, and rarely, cancer.

Radiologists use the Prostate Imaging Reporting and Data System (PI-RADS) score to report how likely it is that a suspicious area of the prostate is a clinically significant cancer. PI-RADS scores range from 1 (most likely not cancer) to 5 (very suspicious). Usually a score of 5 represents a high possibility that prostate cancer is present.

An indeterminate prostate lesion is an area of prostate tissue that has been damaged by injury or disease with an unclear cause. It may be a result of prostatitis (inflammation of the prostate gland) or low-grade carcinoma (slow-growing cancer).

A normal prostate volume is approximately 20 cc. An enlarged prostate is >20 cc and may or may not cause urinary symptoms. If it does not cause any symptoms, then it does not need to be treated. The prostate volume is calculated based on a radiologist’s measurements. Enlarged prostate is not life threatening.

Kidney atrophy means that the kidney is smaller than normal. A greater decrease in kidney size, especially for both kidneys, can lead to kidney failure. Atrophy of one kidney may elicit compensatory hypertrophy (enlargement) of the healthy kidney.

Dysplastic kidneys (also known as kidney dysplasia) is a condition in which the internal structures of one or both of the kidneys does not develop properly during fetal development. Genetic factors can cause kidney dysplasia.

Kidney atresia means that the kidney is smaller than normal. This can happen for two basic reasons. The first is that part of the kidney does not develop completely from birth (called a congenital problem). The second type happens after birth, and can occur in one or both kidneys. This type of kidney atrophy is due to a lower blood supply (i.e. ischemia) to the kidney(s) and/or loss of nephrons, the basic working units of the kidneys. Chronic infections or blockage of the kidney can also result in kidney atresia.

Usually there are two renal arteries that branch off from the abdominal aorta (the main blood vessel that exits the heart and brings oxygen-rich blood to the rest of the body). An accessory "extra" renal artery is a common variant of the renal arteries. They are common findings in approximately 25% of the population.

Angiomyolipoma (AML) is a benign (non-cancerous) tumor of the kidney that is composed of blood vessels, fat, and smooth muscle cells. Symptoms from AMLs are rare but can include hematuria (blood in the urine), flank pain, hypertension, impairment of kidney function, and can lead to life-threatening rupture.

Hydronephrosis is the swelling (fullness) of a kidney due to the build-up of urine. It happens when urine cannot drain properly from the kidney to the bladder due to a blockage or obstruction. The condition can occur in one or both kidneys.