Which scan is considered best for detecting kidney stones?

The best scan for detecting kidney stones is a CT scan without contrast. This imaging modality is highly sensitive and specific for identifying urinary calculi, allowing for the visualization of stones of various compositions and sizes, regardless of their location within the urinary tract. A non-contrast CT scan provides a clear view of the kidneys, ureters, and bladder, enabling healthcare providers to accurately diagnose the presence of kidney stones.

Additionally, a CT scan can quickly cover a large area, making it effective in emergency settings where immediate diagnosis is crucial. Unlike other imaging techniques, CT scans are particularly adept at detecting even very small stones that might not be visible on other imaging studies.

While MRI with contrast is useful for evaluating soft tissue and vascular structures, it is not typically employed for assessing kidney stones due to lower sensitivity for calcifications. Ultrasound can be helpful in certain populations, such as pregnant women or those who require a radiation-free option, but it may miss small or non-obstructive stones. X-ray is less effective as well since many small stones are not radiopaque and would not be detected. Thus, CT without contrast is recognized as the gold standard for diagnosing kidney stones.