Comparison of emergency cranial CT interpretation between radiology residents and neuroradiologists: transverse versus three-dimensional images

Abstract

Purpose: Three-dimensional (3D) reformatted images provide a more inclusive representation of abnormalities than transverse images in cranial computed tomography (CT). The purpose of this study was to assess the value of 3D reformations for radiology residents in the interpretation of emergency cranial CTs.

Materials and methods: In total, 218 consecutive patients who underwent emergency cranial CT scans with 3D reformation were included in this retrospective study. Four blinded readers (three radiology residents and a neuroradiologist) interpreted the transverse and 3D images in two separate sessions. Each reader assessed 1) abnormal finding(s) and the confidence score(s) (5-point scale) for transverse and 3D images, 2) added value score of 3D images (5-point scale), and 3) interpretation time for both transverse and 3D images. We analyzed discordance between each radiology resident and the neuroradiologist on a lesion-by-lesion basis.

Results: In total, 509 lesions were detected in 218 patients. Discordance rates between the three residents and the neuroradiologist were 11.4%-20.2% (mean, 15.0%) and 8.8%-16.9% (mean, 12.1%) in the interpretation of transverse and 3D images, respectively. Confidence scores were higher for 3D images than for transverse images for all readers. The added value scores for the 3D images were relatively higher for the inexperienced residents. Interpretation times for 3D images were significantly higher than for transverse images for all readers.

Conclusion: The 3D reformations assist radiology residents in the interpretation of emergency cranial CT examinations.

Figure 1. a–c.

A 48-year-old male with head trauma. Unenhanced transverse CT image (a) shows a small right subdural hematoma (black arrows) that was identified only by the neuroradiologist (missed by all three radiology residents), and a questionable contusion in the left inferior frontal lobe (white arrow) that was missed by all four readers. Coronal (b) and sagittal (c) reformatted images show a small right subdural hematoma (b, black arrows) and a small left inferior frontal lobe contusion (b, c, white arrows), which were identified by all four readers. Additionally, there is a right temporoparietal subarachnoid hemorrhage (a, b, arrowheads), which was identified by all four readers.

Figure 2. a–c.

A 28-year-old female with head trauma. Unenhanced transverse CT image (a) shows a thin left epidural hematoma (arrow) that was correctly diagnosed by the neuroradiologist and a radiology resident (missed by two residents). On coronal (b) and sagittal (c) reformatted images, all four readers identified a left epidural hematoma (arrows).

Figure 3. a–c.

An 82-year-old male with head trauma. Unenhanced transverse CT image with a bone window setting (a) shows a fracture line (arrow) in the right parietal region. The neuroradiologist and a radiology resident identified a fracture in the transverse plane (missed by two residents). Coronal (b) and sagittal (c) reformatted images clearly show a linear fracture (arrows) through the right parietal bone, which was identified by all four readers.