The recording of an x-ray of the urinary bladder for diagnostic purposes.
A test to help determine the cause of abnormal bladder emptying found in certain diseases, such as diabetes mellitus. First, the patient urinates normally, and the amount of urine, length of time during urination, and any amount of straining or dribbling are recorded. Then a thin, flexible tube (catheter) coated with anesthetic jelly is inserted through the urinary tract into the bladder; the amount of urine remaining in the bladder is drained and measured. Next, saline solution at room temperature is pumped into the bladder through the catheter, and the patient reports any sensation. After the saline solution is drained, a device that measures bladder pressure (cystometer) is connected to the catheter. Water, or in some cases carbon dioxide gas, is slowly pumped into the bladder. The amount of water or gas and its pressure are recorded as the patient reports first the need to urinate, then a sense of fullness, and finally the point at which urination begins. The data gathered in a cystometrogram, often combined with other test results, can help a physician diagnose the cause of abnormal bladder function.