Measurement Of Geniculate Fossa And Its Value In Clinical Application

Objective: Range of normal values of geniculate fossa (GF) were established.Value of GF enlargement in the diagnosis of GF fracture was evaluated. Materials and Methods:HRCT images of 50 cases without any facial nerve diseases were collected.Images of all cases were postprocessed using MPR. Four kinds of standard measurement sections were reformatted. 5 kinds of lines were designed to measure the GF.Statistical analysis were done to analyze the difference between the group in different age,sex,and left-right.35 cases of traumatic facial never palsy were collected.Fracture of GF were seen in all cases during the process of facial never decompression.MPR were performed in all cases followed by measurement of the 5 lines.Difference of all lines between the abnormal and normal group were analyzed.Sensitivity of GF enlargement in the diagnosis of its fracture were calculated based on the result of operation. Results:1. In normal group,all measurements of GF had difference in different age group.2. In normal group,all measurements of GF had no difference in male and female group,left and right group.3. Range of normal values of GF in normal group older than 20 years were as following:A: 2.81-2.95mm, B: 3.23-3.35mm, C: 1.59-1.67mm, D: 1.62-1.71mm, E: 3.20-3.33mm.4. All measurements of cases in abnormal group that older than 20 years had significant difference with normal group.5. Among the cases in abnormal group that older than 20 years: .A englarged in 18 cases, sensitivity of line A enlargement in the diagnosis of GF fracture was 58.06%.B enlarged in 28 cases,the sensitivity was 84.85%.C enlarged in 28 cases,the sensitivity was 87.50%.D enlarged in 22 cases,the sensitivity was 73.33%.E enlarged in 27 cases,the sensitivity was 81.82%.31 cases had at least one line enlarged,the sensitivity of combined using of all lines was 93.94%. Conclusions:1. Range of normal values of GF aid to diagnosis of GF enlargement were established .2. In the four kinds of standard measurement sections ,enlargement of line B and C have higher sensitivity in the diagnosis of GF fracture.Coronal image of GF was easy to reformatted and influenced little by subjective factors,so it should be the routine measurement section.Combined using of line A to line E had the highest sensitivity.3. In case of the direct sign of GF fracture was obvious on HRCT,it's no need to measure the lines to determine the diagnosis of fracture.In case of no obvious fracture line was seen on HRCT, measurement of GF was the main base to the diagnosis of fracture.