# Multidetector Computed Tomography Used in Evaluation of Olfactory Fossa Depth in a Tertiary Hospital: A Descriptive Cross-sectional Study

## TL;DR

This study uses CT scans to classify olfactory fossa depth in 530 patients, finding that type II is most common and type III is rare but more dangerous.

## Contribution

The study provides a descriptive analysis of olfactory fossa depth using MDCT and Keros classification in a large patient cohort.

## Key findings

- Keros type II olfactory fossa was most common (68.88%) in the study population.
- Type III olfactory fossa, considered dangerous, had low prevalence (1.88%) and was more common on the right side and in males.

## Abstract

Olfactory fossa (OF) is a depression in most infero-medial portion of anterior cranial fossa formed by cribriform plate, crista galli and lateral lamella of cribriform plate (LLCP). LLCP being thinnest and extremely variable parts, more prone for iatrogenic injury during sinus surgery in case of asymmetric and deep OF. Multidetector computed tomography (MDCT) is frequently used imaging modality in the evaluation of paranasal sinus. The objective of the study is to classify the OF depth according to the Keros classification.

In this ethically approved prospective, cross-sectional descriptive study, CT scan was done in 530 consecutive patients from February 2022 to July 2023. Coronal CT images of paranasal sinuses and nose were used to measure the OF depth. The data collected was analyzed using SPSS.

Out of 530 patients included in this study, 310 (58.49%) were male and 220 (41.51%) were female with mean age of 40.46±11.56 years. Total of 1060 olfactory fossa were analyzed with mean depth of 4.96±1.88 mm. In our study, 310 (29.24%) had type I, 730 (68.88%) had type II and 20 (1.88%) had type III according to Keros classification.

Keros type II OF is more common. The dangerous type III OF having low prevalence, more commonly seen on right side and in males.