Basket device – A small instrument that can be passed through a ureteroscope or nephroscope to entrap a stone so that it can be removed from the patient.

Bladder – the organ where urine is stored between the times of urination

Calyx – location in the kidney that is the beginning of the urinary collecting system. Most kidneys have between 6 and 10 of them. During ureteroscopy and PERC, it is critical to inspect every calyx, to be sure that no stone has been overlooked. The plural of calyx is calyces.

CT scan – one of the most effective ways to evaluate a patient for the presence of stones. When looking for stones, no oral or intravenous (IV) contrast is necessary.

Cystoscope – A specialized telescope that is passed through the urethra to look inside the bladder. Most cystoscopes are ~5 mm in diameter.

Distal ureter – the final end of the ureter, right before it opens up into the bladder. One of the narrowest points of the ureter is right where it enters into the bladder, and stones often become stuck in this location.

Infundibulum – the connection between the calyx and the renal pelvis. In many cases a single infundibulum will collect the urine from several calyces.

Intravenous pyelogram (IVP) – X-rays are obtained of the abdomen prior to and then following the injection of intravenous (IV) contrast. In the evaluation of patients with stones, IVP has been all but replaced by CT scanning.

KUB – a plain x-ray of the abdomen, which images the kidney, ureter, and bladder.

Laser – An acronym that stands for light amplification by stimulated emission of radiation. The Holmium:YAG laser is the most commonly used laser to break up stones. Stones are broken up primarily by a thermal energy transfer.

Lithotripsy – the process of breaking up a stone.

Lower pole – the bottom-most part of the kidney's collecting system. Stones in this location tend to not respond as well to ESWL and ureteroscopy, as fragments often persist in this location following treatment, promoting the formation of new stones.

Middle ureter – the portion of the ureter between the proximal ureter and the distal ureter. Anatomically, this is the portion of the ureter that overlies the bony pelvis. The iliac blood vessels, a very large artery and vein, cross under the middle ureter, pressing in and slightly narrowing the ureter at this point. As a consequence of this narrowing, stones can become trapped at this location.

Nephroscope – A specialized telescope used to examine the interior of the kidney and to remove stones from the kidney. Most nephroscopes are ~8 mm in diameter.

Nephrostomy tube – a small, soft, plastic tube used to temprorarily drain the kidney. Most nephrostomy tubes are less than 5 mm in diameter.

Papilla – The location where urine leaves the filtering tubules of the kidney tissue and enters the collecting system. Many times, stones are found attached to papilla.

Pneumatic lithotripter – A jackhammer-like device that is used to break up stones.

Proximal ureter – The portion of the ureter between the kidney and the middle ureter.

Randall's plaque – small deposits of calcium phosphate on the tip of the renal papilla. Calcium oxalate stones are frequently found attached to Randall's plaque.

Renal colic – the severe symptoms associated with the passage of a stone. Common symptoms include pain in the flank or groin accompanied by nausea and vomiting.

Renal pelvis – the central point to which all of the different infudibula drain.

Renal tubular acidosis – a disease in which a person's kidneys are unable to properly acidify their urine, leading to a build-up of acid in the blood and a build-up of alkali in the urine. These patients commonly form calcium phosphate stones.

Staghorn stone – a large kidney stone which has grown so as to completely fill the renal pelvis, infundibula, and calyces. So named because a stone of this configuration resembles the horns of a deer, or stag.

Tether – a thin string, or thread, that is affixed to the end of a ureteral stent. Pulling on the tether will remove a ureteral stent, eliminating the need for a cystoscopic procedure to remove the stent.

Upper pole – the top-most part of the kidney's collecting system.

Ureteral stent – a small plastic tube used to temporarily drain the kidney. Most ureteral stents are ~2 mm in diameter.

Ureteropelvic junction (UPJ) – the region where the renal pelvis joins the ureter. The UPJ is a site where stones may become trapped when they begin to pass out of the kidney.

Ureter – the long, narrow tube that transports urine from the kidney to the bladder.

Ureteroscope – A specialized telescope that is used to examine and treat stones or other disease in the ureter. Most ureteroscopes are ~3mm in diameter.

Urethra – The tube that carries urine from the bladder to the outside of the body.

Urinary Collecting system – The part of the urinary tract extending from the renal calyces to the bladder.

Watchful waiting – a treatment strategy whereby kidney stones are not actively treated, but instead are monitored over time, with periodic x-rays, to ensure that they are not changing or causing problems.