S Steinbach1, A Fitzthum, M Reiser, W Hundt. 1. Hals-Nasen-Ohren-Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Ismaninger Strasse 22, 81675, München. S.Steinbach@lrz.tum.de
Abstract
BACKGROUND: The petromastoid canal was first described in 1904 by Mouret and Rouviere. Since then, there have been very few publications about this canal. Modern high-resolution computed tomography (CT) enables a slice thickness of 1 mm and less, so the course of the petromastoid canal is visible. In this study the petromastoid canal is introduced and its dimensions measured. MATERIALS AND METHODS: This study involved 316 CT scans of normal temporal bones of subjects age 19.6-84.2: 156 temporal bones of women and 160 temporal bones of men. The slice thickness of the CT scan was 0.5 mm, and 16-slice or 64-slice CT was used. The middle diameter, length, and angle of the petromastoid canal were measured. RESULTS: The middle diameter of the petromastoid canal was 1.16+/-0.4 mm (0.25-2.5 mm), the length was 10.7+/-0.9 mm (4.25-16.1 mm), and the angle was 134.5+/-17.3 degrees (124-157 degrees). CONCLUSION: The study shows for the first time the length and angle of the petromastoid canal. A slice thickness of at least 1 mm guarantees 100% imaging of the petromastoid canal. The petromastoid canal is an important anatomical landmark and is of clinical relevance.
BACKGROUND: The petromastoid canal was first described in 1904 by Mouret and Rouviere. Since then, there have been very few publications about this canal. Modern high-resolution computed tomography (CT) enables a slice thickness of 1 mm and less, so the course of the petromastoid canal is visible. In this study the petromastoid canal is introduced and its dimensions measured. MATERIALS AND METHODS: This study involved 316 CT scans of normal temporal bones of subjects age 19.6-84.2: 156 temporal bones of women and 160 temporal bones of men. The slice thickness of the CT scan was 0.5 mm, and 16-slice or 64-slice CT was used. The middle diameter, length, and angle of the petromastoid canal were measured. RESULTS: The middle diameter of the petromastoid canal was 1.16+/-0.4 mm (0.25-2.5 mm), the length was 10.7+/-0.9 mm (4.25-16.1 mm), and the angle was 134.5+/-17.3 degrees (124-157 degrees). CONCLUSION: The study shows for the first time the length and angle of the petromastoid canal. A slice thickness of at least 1 mm guarantees 100% imaging of the petromastoid canal. The petromastoid canal is an important anatomical landmark and is of clinical relevance.