Radiologic changes in the aging nasal cavity.

BACKGROUND: With an aging population, it is important to understand age-related anatomic changes in the nasal cavity and cribriform plate (CP) that may have clinical implications. METHODOLOGY: Computed tomography (CT) scans obtained for non-rhinologic conditions were divided into a young cohort (N=35, 18-34 years old) and an older adult cohort (N=32, 80-99 years old). Intranasal airspace volumes and bony anatomy of the CP were manually segmented using OsiriX software. The CP was assessed for mean Hounsfield Units (HU) and percentage of olfactory foramina. Deformation based morphometry (DBM) was then performed on the same cohort and correlated with manual measurements. RESULTS: Individual nasal cavity volumes increased 17-75% with age. Regression analysis of all scans revealed age to be the predominant variable influencing intranasal volume differences when controlling for sex and head size. Mean HU of the CP negatively correlated with age. No age-related differences in bone stenosis of olfactory foramina were identified. Automated DBM measurements of intranasal volumes, as well as CP and zygoma mean HU correlated with manual measurements. CONCLUSION: Older subjects have a global increase in intranasal volumes and diffuse bone density loss in the CP. The clinical impact of age-related anatomic changes in the nasal cavity and CP requires further investigation.

Novel Radiographic Assessment of the Cribriform Plate.

Background The cribriform plate (CP) is a common site of spontaneous cerebrospinal fluid (SCSF) leaks. Radiographic assessment of the anterior and lateral skull base has shown thinner bone in patients with SCSFs; however, prior assessment of the CP has required postmortem cadaver dissection. Objective To develop novel radiographic techniques to assess the anatomy of the CP. Methods Computed tomography (CT) scans were performed on cadaveric specimens. Bone density and anatomy of a predefined volume of interest of the posterior CP were assessed by two independent reviewers. CT assessment of olfactory foramina was also performed and validated using anatomic dissection of cadaver specimens. Results Interclass correlation coefficients (ICCs) for measuring the same volume of each CP was 0.96, confirming reproducible anatomic localization. Cadaver CPs had a mean Hounsfield units of 263, indicating a mix of bone and soft tissue, and ICC was 0.98, confirming reproducible radiographic measurements. Optimal CT estimates of bone composition of CPs averaged 85% (range 76% to 96%) compared to actual anatomic dissection which averaged 84% bone (range 74% to 91%, r = .690, P = .026). Conclusion Our novel, noninvasive CT method for assessing CP anatomy is reproducible and correlates with anatomic dissection assessing bone composition. The clinical implications of anatomic changes in the CP are an area for further study.