How are kidney stones typically diagnosed?

Kidney stones are most commonly diagnosed with a CT abdomen/pelvis without contrast due to the high sensitivity and specificity of this imaging method. A non-contrast CT scan provides detailed images of the urinary tract and can easily identify the presence, size, and location of kidney stones. This imaging technique is preferred because it quickly reveals stones that are otherwise difficult to detect using other methods, even very small ones.

In comparison, an X-ray of the abdomen has limitations since not all types of kidney stones are radiopaque; for example, uric acid stones might not be visible. While an MRI can be supremely useful in certain situations, it is not typically employed for diagnosing kidney stones due to cost, availability, and speed compared to a CT scan. An ultrasound is useful, particularly in pregnant patients or for assessing hydronephrosis, but it may not provide the same level of detail regarding stone characteristics or may miss smaller stones. Thus, the CT abdomen/pelvis without contrast remains the gold standard for diagnosing kidney stones effectively.