Question

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

Short answer

Answer: C. Noncontrast helical computerized tomography (CT)

Step-by-step solution

Understand the concept of sensitivity

Sensitivity is the ability of a diagnostic test to correctly identify individuals with a specific condition. In this case, we want a diagnostic measure with the highest sensitivity, meaning it will be best at detecting renal calculi among the patients.

Analyze each diagnostic measure

Let's briefly discuss the four given diagnostic measures: A. Magnetic Resonance Imaging (MRI): Although MRI has excellent soft-tissue resolution, it is generally not the first-line investigation for renal calculi (kidney stones) due to its cost and limited availability. B. Ultrasonography: Ultrasonography is a readily available and non-invasive diagnostic tool. It can detect renal calculi; however, its sensitivity varies depending on the operator's skill, patient factors, and stone size/location. C. Noncontrast helical computerized tomography (CT): Noncontrast helical CT is the gold standard for diagnosing renal calculi due to its high sensitivity and specificity, as it identifies almost all types of stones and provides detailed information about their size, location, and composition. D. X-ray of the kidneys, ureter, and bladder (KUB): X-rays (KUB) are a low-cost and non-invasive option to diagnose renal calculi. However, its sensitivity is lower compared to other diagnostic tools since not all kidney stones are radiopaque.

Choose the diagnostic measure with the highest sensitivity

Based on the analysis of each diagnostic measure, we can conclude that Noncontrast helical computerized tomography (CT) has the highest sensitivity for detecting renal calculi. So, the correct answer is: C. Noncontrast helical computerized tomography