The physician has ordered several diagnostic measures for a client with suspected renal calculi. Which diagnostic measure has the highest sensitivity for detecting renal calculi? A. Magnetic resonance imaging B. Ultrasonography C. Noncontrast helical computerized tomography D. X-ray of the kidneys, ureter, and bladder

To determine which diagnostic measure has the highest sensitivity for detecting renal calculi, we first need to understand what each of these options are: A. MRI uses magnetic fields and radio waves to create detailed images of the organs and tissues within the body. B. Ultrasonography uses high-frequency sound waves to produce images of the internal structures of the body. C. Noncontrast helical CT scan uses X-rays and advanced computer programs to create detailed cross-sectional images of the body. In this case, no contrast dye is used. D. KUB X-ray is a type of X-ray specifically used to examine the kidneys, ureters, and bladder. It creates a 2D image of these organs.

Now that we know what each diagnostic measure is, let's compare their sensitivity: A. MRI - While MRI has high sensitivity in detecting soft tissue abnormalities, it is not as accurate in detecting renal calculi as other methods. B. Ultrasonography - It can be used to detect renal calculi, but its sensitivity may be lower than other methods, especially for small stones or if the stones are located in the lower ureter. C. Noncontrast helical CT - It has high sensitivity and specificity for detecting renal calculi, even small stones. It is considered the gold standard for detecting renal calculi. D. KUB X-ray - Although it can detect some renal calculi, it has a lower sensitivity compared to other methods, particularly for small stones or non-radio-opaque stones.

Based on the comparison of the different methods, it is clear that noncontrast helical CT (Option C) has the highest sensitivity for detecting renal calculi. Therefore, the correct answer is: C. Noncontrast helical computerized tomography