How is nephrolithiasis typically diagnosed?

Nephrolithiasis, or kidney stones, is primarily diagnosed through imaging techniques that can effectively visualize the urinary tract and identify the presence of stones. The non-contrast CT scan is considered the gold standard for diagnosing nephrolithiasis because it provides high sensitivity and specificity. This imaging modality can quickly and accurately detect even small stones in the kidneys and ureters, as it does not rely on contrast agents that can sometimes obscure findings.

Additionally, non-contrast CT scans are particularly advantageous in emergency settings because they are rapid and do not require patient preparation or the use of intravenous contrast, which can pose risks for certain patients, such as those with renal impairment. This efficiency and clarity make the non-contrast CT scan the preferred diagnostic tool in cases of suspected nephrolithiasis.

While other imaging modalities like ultrasound and X-rays can be used, they have certain limitations. Ultrasound is less sensitive for detecting stones in the ureters, and while X-rays can help visualize some types of stones, they do not provide the comprehensive view that a non-contrast CT scan offers. MRI, on the other hand, is not used for diagnosing nephrolithiasis due to its lower availability and the challenges associated with imaging stones compared to CT.