Which imaging technique is most often used to diagnose kidney stones?

The most commonly used imaging technique to diagnose kidney stones is a CT scan, specifically a non-contrast computed tomography (CT). This method provides highly detailed cross-sectional images of the abdomen and pelvis, allowing for a precise identification of kidney stones, regardless of their size or composition. CT scans are particularly effective because they can visualize stones that may not be as clearly seen on other imaging modalities.

CT scans have a significant advantage in speed and sensitivity, making them the preferred choice in acute settings, such as when a patient presents with severe flank pain that may indicate a kidney stone. They can detect not only the presence of stones but also any complications that may arise, such as obstruction or hydronephrosis.

Other imaging techniques like ultrasound and X-ray can be useful in some cases, but they have limitations. For instance, ultrasound might miss small stones or those that are obscured by bowel gas, while traditional X-rays may not visualize all types of kidney stones effectively, particularly those made of uric acid which are radiolucent. MRI, while excellent for soft tissue assessment, is not routinely utilized for kidney stone evaluation due to its lower availability and longer scanning times.