Value of coronal reformations in the CT evaluation of acute head trauma

Abstract

Background and purpose: Routine axial CT images may not be ideally suited for detecting ICH in transversely oriented locations such as the floor of the anterior and middle cranial fossas and vertex. This study was performed to evaluate whether coronal reformations improve detection of ICH in NCCT performed for head trauma.

Materials and methods: All patients undergoing a first NCCT in the ED for evaluation of head trauma were included prospectively during a 6-month interval. NCCT images were reconstructed into standard 5-mm axial datasets and were also reformatted into coronal datasets of 5-mm sections and 2.5-mm intervals. Thirty-two of 213 (15%) scans were interpreted as showing traumatic ICH. These cases were interspersed with 30 studies without ICH. Cases were reviewed for the presence and location of ICH by 2 staff neuroradiologists.

Results: Of 213 patients, 32 NCCTs demonstrated ICH (a total of 104 foci). Fifteen of 104 (14%) ICHs (8 patients) were detected solely on coronal images. Locations included the floor of the anterior and middle cranial fossas, vertex, corpus callosum, falx, tentorium, and occipital convexity. Coronal reformations allowed exclusion of suspicious findings on axial images in 14 instances (7 patients). Coronal images aided interpretation in 29/104 (28%) findings.

Conclusions: Coronal reformations improve the detection of ICH over axial images alone, especially for lesions that lie in the axial plane immediately adjacent to bony surfaces. The use of coronal reformations should be considered in the routine interpretation of head CT examinations performed for the evaluation of head trauma.

Fig 1.

A, A small hemorrhagic contusion (white arrow) is partially obscured by volume averaging with the adjacent bone. B, The same lesion is more conspicuous and confidently identified on coronal reformations (white arrow). A small right subdural hematoma (black arrow) is noted. C, On the corresponding axial image, no abnormality can be identified in the region of the small right subdural hematoma (small white arrow).

Fig 2.

A, Hyperattenuation (arrow) in the superficial right temporal lobe is partially obscured by volume averaging through the temporal bone. B, A clear focus of hemorrhagic contusion (arrow) is seen on the corresponding coronal image.

Fig 3.

A, A small focus of parenchymal hemorrhage (arrow) is clearly seen in the corpus callosum on the coronal reformation. B, The lesion (arrow) is much more subtly apparent on the corresponding axial image.

Fig 4.

A, Minimal thickening of the anterior falx (arrow) is not prospectively identified on initial review of the axial images. B, This is confirmed to represent a small subdural hematoma (arrow) on the corresponding coronal image.

Fig 5.

A, Hyperattenuated focus (arrow) in the left cerebellum interpreted as suspicious for parenchymal hemorrhage. B, Coronal images show that the finding represents tentorial calcification (arrow).

Fig 6.

A, A small focus of pneumocephalus (arrow) is related to a nondisplaced fracture through the left temporal bone. B, On the axial images, the findings are obscured due to volume averaging through neighboring mastoid air cells (arrow).

Fig 7.

Three coronal images show a tranverse nondisplaced fracture (arrows) through the right parietal bone. The corresponding axial images show no evidence of fracture (arrows).