Image-guided Temporal Bone Dissection Course

Abstract

Introduction Temporal bone anatomy is complex and demands a profound anatomical knowledge. Association between surgery and imaging helps in the process of learning three-dimensional (3D) anatomy and surgical techniques. High definition temporal bone imaging can play an important role in dissection training. Objective To describe a computed tomography (CT) image-guided temporal bone dissection course for surgical training in otolaryngology and to verify the satisfaction level of the students with the course. Methods Descriptive research. The course took place at a research laboratory, with three experienced temporal bone surgeons. The participants were 12 otolaryngology residents. The laboratory has 7 modern workstations with microscope and monitors linked with a computerized video system. Cadaveric temporal bones were donated to the university. Imaging acquisition of the cadaveric temporal bones used in the course was performed in a multislice CT scanner. The CT images of cadaveric temporal bones were available with real-time access on the laboratory monitor's screens during dissections. Results A total of 13 temporal bones were included for dissection. Students had the opportunity to view on the same screen, simultaneously, both the dissection video and the respective CT images of their temporal bone anatomical specimens. This allowed correlating surgical and imaging aspects of temporal bone anatomy. At the end of the course, participants answered a satisfaction survey. Conclusion Considering imaging methods are routinely used during most otologic surgeries, detailed knowledge of CT imaging should be explored in conjunction with the temporal bone anatomical dissection.

Keywords: anatomy; computed tomography; dissection; temporal bone.

Fig. 1

Photograph of one of the cadaveric temporal bones utilized in the course.

Fig. 2

Imaging acquisition of the temporal bones using a multislice CT scanner. Abbreviation: CT, computed tomography

Fig. 3

Workstation with a MC-M22 microscope (DF Vasconcellos Ltda.) and a computerized video system linked with a monitor. Screen shows simultaneously the video of dissection transmitted in real time from microscope next to a software window with CT images of the temporal bone being dissected. Abbreviation: CT, computed tomography

Fig. 4

Instructor's dissection workstation, equipped with a OPMI VARIO S88 microscope ( (Carl Zeiss SMT GmbH), surgical instruments, video system and a monitor (not shown).

Fig. 5

CT imaging reconstruction (postprocessing) using 3D volume rendering technique; lateral view, demonstrating the mandibular condyle (a; also called condylar process of the mandible); zygomatic arch (b); styloid process (c); mastoid portion (part) of temporal bone (d); external auditory canal (e; yellow arrow; also called external auditory meatus or external acoustic meatus). Some data present in this reconstructed 3D image has been omitted (using black rectangles) to avoid any kind of identification. Abbreviations: CT, computed tomography; 3D, Three-dimensional.

Fig. 6

Photograph of a dissected temporal bone and a CT image (postprocessed), showing some correlated anatomical structures. 6.a : result of dissection of a cadaveric specimen of temporal bone during the course, demonstrating: facial nerve (a); jugular bulb (b); internal auditory canal (c; also called internal auditory meatus or internal acoustic meatus). 6.b : CT MPR in an oblique axial plane, demonstrating the carotid canal (a; medially to the cochlea); sigmoid sinus/jugular bulb (b; yellow arrows; inferiorly and laterally to the cochlea); mastoid air cells (c); cochlea and vestibule (d); facial nerve (e; yellow arrows); tegmen (f). Abbreviations: CT, computed tomography; MPR, multiplanar reconstruction or reformation.

Fig. 7

: CT multiplanar reconstruction (MPR) in an oblique coronal plane demonstrating the cochlea (a); mastoid air cells (b); carotid canal (c); vestibule and semicircular canals (d); tegmen (e). Abbreviations: CT, computed tomography; MPR, multiplanar reconstruction or reformation.