What is the diagnostic test of choice for nephrolithiasis?

The diagnostic test of choice for nephrolithiasis is helical CT. This imaging modality is highly effective in identifying kidney stones due to its ability to provide detailed cross-sectional images of the abdomen and pelvis without the need for contrast. Helical CT scans can rapidly assess the size, location, and number of stones, and they are particularly useful because they can detect stones of all types and density, including those that are not visible on conventional X-rays.

In cases where a patient presents with acute flank pain suggestive of nephrolithiasis, a helical CT scan enables quick diagnosis and intervention planning, which is crucial for pain management and further treatment options. This technique is favored over other imaging modalities due to its high sensitivity and specificity, making it the first-line investigation in most situations involving suspected kidney stones. Additionally, helical CT does not involve exposure to ionizing radiation levels as high as those associated with a traditional X-ray series, further enhancing its clinical utility.

While ultrasound is a useful alternative, especially in pregnant patients or those requiring avoidance of radiation, it may not provide sufficient detail in all cases, particularly for stones located in certain areas of the kidneys or ureters. X-rays can identify some stones but lack the sensitivity to detect all types