57Cases Of Adult Posterior Fossa Volume Measurement Research(with Case-Control)

Objective:Measured the posterior fossa of57adult patients, and got the adult posterior fossa volume data values, while compared with Chiari type I malformation patients, in order to provide a quantitative reference for the evaluation of Chiari type I malformation diagnosis.Method:1.The experimental group selection criteria:selected randomly craniocerebral MRI of the health adult crowd as the experimental group.29cases were male, age17--58year old, average32.9years old, female28cases, age17--64years old, average41.5years old. All were not associated with Chiari malformation, basilar invagination, atlanto occipital fusion, atlantoaxial dislocation, intracranial tumor, congenital hydrocephalus, skull malformations.and nervous system diseases or other diseases.2. At the corresponding period, we selected48cases of patients diagnosed with Chiari type I malformation patients (tonsillar hernia were more than5mm) as the control group, and22cases were male, age22--50year old, average33.4years old, female26cases, age23--54years old, average38.1years old. Patients were excluded from basilar invagination, atlanto occipital fusion, atlantoaxial dislocation, intracranial tumor, congenital hydrocephalus, skull malformations.hydrocephalus or nature of brain malformations and so on.3. the measurement method of posterior fossa volume:in magnetic the picture, we used pixel method of Photoshop software to obtain delineated posterior fossa area and the maximum transverse diameter values of posterior fossa, and used the quasi column to calculate the volume of posterior fossa. The normal group and the control group were used for the same method of measurement. 4using t test to test the values of experimental group and control group (Men and women were separated to measure.), and sected a=0.05as the level of test to do statistical analysis.Result:The measurement results show that the male posterior fossa volume value of the experimental group,:184.69±17.78cm3, female:163.92±13.52cm3, control group: male:178.21±25.30cm3, female:158.82±15.13cm3.Statistical analysis:(1) the posterior fossa volume of male in experimental group were larger than that men of the control group, no statistically significant difference (P>0.05).(2) the posterior fossa volume of female in experimental group were larger than that women of the control group, there was no significant difference (P>0.05).(3) the posterior fossa of male in experimental group were significantly larger than females (P<0.05), in the control group, male was significantly higher than female (P<0.05), there was significant difference.(4) to comparison of mixed average value, the posterior fossa volume of experimental group were larger than the control group, and the difference was not significant (P>0.05).Conclusion:1. the posterior fossa volume of male in normal group and CMI group were larger than females, the difference was significant, indicating that sex differences is very obvious in posterior fossa volume, and gender factors need to be considered in clinical measurement and evaluation of application2. Comparison of the same sex, the posterior fossa volume of male in normal group than that of the CMI group, and the posterior fossa volume of female in normal group than that of the CMI group, but the difference was not significant.,which indicated that the posterior fossa volume of Chiari type I malformation patients compared with normal subjects did not reduce.3. Although there was difference between the same gender of two groups, but no statistical significance, so the method mentioned in the literature of previous studies with the population average mixed was not appropriate,. The hypothesis that the posterior fossa of Chiari type I malformation was narrow was possibly questionable.