Critical Care Registered Nurse (CCRN) Practice Exam

Which imaging technique is critical for diagnosing encephalitis?

1. Ultrasound

2. CT scan

3. MRI

4. X-ray

The correct answer is: CT scan

In the context of diagnosing encephalitis, a CT scan plays a vital role, but it is important to clarify that while CT scans can provide some information, MRI is generally considered the preferred imaging technique for this condition. MRI is superior in visualizing soft tissue structures, including the brain and its potential pathologies, which is particularly important in cases of encephalitis. It can reveal characteristic findings such as hyperintensities in the temporal lobes, which are associated with viral infections. MRI is also helpful in identifying complications that may arise from the inflammation associated with encephalitis, such as edema, hemorrhage, or atrophy. CT scans, while still useful as a first-line evaluation, especially in emergency settings to rule out other potential causes of altered mental status (like hemorrhage or tumor), may not provide the detailed information required to diagnose and evaluate encephalitis thoroughly. Therefore, although CT scans can aid in the evaluation, they are not the most critical imaging technique for this specific diagnosis compared to MRI. Thus, the correct technique should be recognized as MRI for a comprehensive assessment of encephalitis.