[FESS and surgical training: what are the problems?]

[Objective and subjective assessment of a structured approach to computed tomography scans of the paranasal sinuses]

BACKGROUND

Sound knowledge of individual anatomy is essential in sinus surgery to prevent potentially serious complications. For the paranasal sinuses, computed tomography (CT) is the imaging technique of choice to preoperatively analyze individual anatomy and the extent of disease.

OBJECTIVE

The purpose of this study was to evaluate the usefulness of a CT checklist to identify relevant anatomic variants in CTs of the paranasal sinuses.

MATERIALS AND METHODS

Junior and senior otolaryngology residents were asked to assess sinus CT scans for anatomic variants before and after implementation of the CLOSE mnemonic (cribriform plate, lamina papyracea, Onodi cell, sphenoid sinus pneumatization, and [anterior] ethmoidal artery). The rate of correctly identified variants was calculated. A questionnaire was distributed for subjective evaluation of the usefulness of the checklist.

RESULTS

Six junior and six senior residents were included in the study. The rate of correctly identified anatomic variations significantly improved from 23.1 to 50.9% and 24 to 39.8%, respectively, after implementation of the CLOSE mnemonic. The subjective evaluation of the CLOSE criteria showed very positive results.

CONCLUSION

The structured approach to sinus CT scans using CT criteria can improve identification of critical anatomic variants in CT scans of the paranasal sinuses and is rated highly positively by residents in training.

Comparison of hand and semiautomatic tracing methods for creating maxillofacial artificial organs using sequences of computed tomography (CT) and cone beam computed tomography (CBCT) images

INTRODUCTION

The aim of this study was to compare the paranasal sinus volumes obtained by manual and semiautomatic imaging software programs using both CT and CBCT imaging.

METHODS

121 computed tomography (CT) and 119 cone beam computed tomography (CBCT) examinations were selected from the databases of the authors' institutes. The Digital Imaging and Communications in Medicine (DICOM) images were imported into 3-dimensonal imaging software, in which hand mode and semiautomatic tracing methods were used to measure the volumes of both maxillary sinuses and the sphenoid sinus. The determined volumetric means were compared to previously published averages.

RESULTS

Isometric CBCT-based volume determination results were closer to the real volume conditions, whereas the non-isometric CT-based volume measurements defined coherently lower volumes. By comparing the 2 volume measurement modes, the values gained from hand mode were closer to the literature data. Furthermore, CBCT-based image measurement results corresponded to the known averages.

CONCLUSIONS

Our results suggest that CBCT images provide reliable volumetric information that can be depended on for artificial organ construction, and which may aid the guidance of the operator prior to or during the intervention.