How can a CT scan tell if you have a kidney stone or cancer or something else?

It shows the kidney. The ct scan that is typically done to look for kidney stones is done without any intravenous contrast. Almost all stones show up easily on ct scan. Renal masses typically show on a non-contrasted ct but they may not be able to tell if it is a cancer or not. The ct also shows other organs in the abdomen and a mass or cancer may be visible on the study.
Great look at anatom. A ct scan provides a great look at the anatomy of the area scanned. If contrast is used, it can also show areas of differing blood flow. A ct displays differences in density with an axial resolution of a millimeter or better.

Related Questions

Can a CT scan radiation cause cancer in future? Done ct scan due to kidney stones. I am 52 male. Please reply.

Don't worry! The risk of getting cancer from radiation exposure to one CT scan is infinitesimally small. You get exposed to more radiation by living your routine life every day. But it's good to remember that radiation dose accumulates, so the more CT scans you have over your life, the higher the risk. It's always a good idea to keep track of how many tests you are having, and to remind your doctor! Read more...

Can I tell if kidney stone has transited from ureter to bladder by change in symptoms? CT scan shows a 4mm stone 1.5 CM from bladder.

See answer. The only true accurate means of determining whether a ureteral calculus has passed is to retrieve it by straining your urine. The chance of spontaneous passage of a 4mm stone ~50-60%. Onset of symptoms of urinary urgency, frequency, burning, voiding small volumes usually indicates the stone is at the UVJ (ureter meets bladder). The absence or disappearance of pain does not guarantee stone passage. Read more...

On a CT scan is it easy to tell a 10mm kidney stone from a tumor. Could they be mistaken?

Yes is easy to tell. Yes you can tell if it is stone vs a tumor even if it is 10 mm.Tumors give appearance of sold mass compared to a stone. Read more...
Not usually. Bobcat: a kidney stone shows up on the ct scan as a bright white spot and the density is measured to insure that it is a calcium deposit/stone. A mass/tumor can have calcifications in it, but the mass would typically be seen and not just the calcium. It may also matter whether you ct was done with and without contrast injection to be sure the stone is not obstructing the urinary tract. Read more...

Could you tell if you had pkd or other kidney problems with a CT scan or ultrasound? Have had same kidney stone for years and I thought theycane out

Some (larger) kidney stones do not "come out" or are a part of the kidney's structure, CT or ULTRASOUND is/are good tests to disclose kidney STONES but are not generally sufficient to study kidney disease which requires blood/urine tests and sometimes renal BIOPSY! Hope this is helpfu Dr Z. Read more...