CT of the Normal Temporal Bone

http://radiology.rsna.org/content/235/1/133.full.pdf+html

Lorenz Jäger, MD, Harald Bonell, MD, Martin Liebl, MD, Sudesh Srivastav, PhD, Viktor Arbusow, MD, Martin Hempel, MD and Maximilian Reiser, MD

PURPOSE: To evaluate multi– and single–detector row computed tomographic (CT) depiction of anatomic landmarks of temporal bone.

MATERIALS AND METHODS: Institutional review board approval and written informed consent were obtained. In 50 temporal bones, transverse and coronal single–detector row CT images were compared with transverse and reformatted coronal multi–detector row CT images obtained of additional 50 temporal bones. Two radiologists evaluated images. Visibility of 50 landmarks was scored with a five-point quality rating scale. Fisher exact test, statistics, and Mann-Whitney U test were used to evaluate imaging technique and landmark visibility.

RESULTS: In delineating landmarks, total interobserver agreement was higher (P < .001) for transverse multi– than for single–detector row CT images. In 60% of landmarks, interobserver agreement was higher (P < .001) for transverse multi– than for single–detector row CT images. In 20% of landmarks, there was no difference, and in another 20% of landmarks, interobserver agreement was higher (P < .01) for single–detector row CT. Total interobserver agreement was higher (P < .01) for coronal multi–detector row reformations than for coronal single–detector row images. In 58% of landmarks, interobserver agreement was higher (P < .001) for coronal multi–detector row reformations than for coronal single–detector row images, while there was no difference in 8%. In 34% of landmarks, interobserver agreement was higher (P < .001) for coronal single–detector row images. Frequency of detected landmarks was higher for transverse (82%) and coronal (88%) multi–detector row images than for corresponding single–detector row images. In 72% of landmarks, transverse multi–detector row images were (P < .05) superior to corresponding transverse single–detector row images in landmark delineation. In 56% of landmarks, reformatted coronal multi–detector row images were (P < .05) superior to coronal single–detector row images in landmark delineation.

CONCLUSION: Multi–detector row CT images, including reformations, better delineate temporal bone anatomy than do single–detector row CT images.