Analysis of the appropriateness of the clinical indications for neuroimaging studies

To determine the most common clinical indications for different diagnostic neuroimaging tests. To analyze the diagnostic yield for each type of test in function of its clinical indication. To quantify the number of additional imaging tests generated as a consequence of pathological findings on the initial study or of the physician's requesting an inappropriate study.

We reviewed the clinical indications and radiological report for computed tomography (CT) and magnetic resonance imaging (MRI) studies of the brain, head, and neck carried out during a 30-day period in three intermediate level hospitals with similar characteristics. We counted the studies with pathological findings and those with normal findings. We recorded cases that required additional imaging studies.

CT and MRI studies of the brain are the most frequently requested neuroimaging studies. The most common indications for examinations requested from the neurology department were headache, head trauma, and acute neurological deficit. The most common indication for examinations requested from the ear, nose, and throat department was hearing loss. The percentage of examinations with pathological findings ranged from 6% to 71% depending on the clinical indication. Additional imaging studies were necessary in 3.5% of the cases.

Most neuroimaging studies are performed for especially prevalent clinical indications; however, in many cases the degree of concordance between the clinical and radiological diagnosis shows there is much room for improvement.