| Part 1 Improving Arnold-Chiari malformation old type and compareing posterior cranial fossa forms of different type patients in the new typingObjective: According to the posterior cranial fossa forms with varying degrees of deformity to retype Arnold-Chiari malformation(CM), and to compare new types of CM in patients with different types of posterior fossa morphology.Method:We collected 49 patients whose image data was complete ,and who ware diagnosed as CM. The performance of basilar invagination in patients were classified as basilar invagination type(Basilar-type CM), then cerebellar tonsillar herniation more than was 5mm classified as common type of CM.And finally tonsillar herniation less than 5mm, and accompanied by syringomyelia, or the medulla oblongata-spinal cord kink, or hydrocephalus, was classified as mild hernia group. Another 107 normal people and 16 patients diagnosed as pure basilar invagination were collected as the control group . Each patient in the above-mentioned groups was measured for their foramen magnum anteroposterior diameter, clivus length, clivus angle, posterior cranial angle, posterior cranial fossa anteroposterior diameter ,transverse diameter and the depth of postertior cranial fossa, cranial vertebra angle, basal angle, cranial base angle, the medulla oblongata - spinal cord angle, internal occipital protuberance to the posterior edge of foramen magnum distance (tuberosity - hole distance), the cerebellar height, transverse diameter, anteroposterior diameter, extent of tonsillar herniation, extent of basilar invagination.Results: Basilar-type CM: There were total 19 cases: 12 cases with syringomyelia. 4 cases with a flat base of the skull. 1 case with scoliosis,10 cases accompanied by atlas hypoplasia,atlantoaxial dislocation, atlanto-occipital fusion.1 case with hydrocephalus.Common type CM: There were total 25 cases: 11 cases accompanied by syringomyelia in, 1 case with diastematomyelia, spinal diastematomyelia,5 cases with the merger flat skull base, 7 cases with hydrocephalus.Mild hernia type CM: There were total 5 cases.4 cases with syringomyelia, 1 case with hydrocephalus.Pure basilar invagination Group: total 16 patients,5 cases with syringomyelia, 1 case with flat skull base, 2 cases with hydrocephalus.The ratio of Basilar-type and Common type CM incidence of syringomyelia wasχ2 = 1.588, P> 0.05.In the posterior cranial fossa structures, except that anteroposterior diameter of the posterior fossa, cerebellum and down trails and canopy angle among the three groups did not have significant differences, the various types and groups all have varying degrees of difference.Conclusion: We could see from the results that mild hernia type's posterior fossa form was nearest normal posterior fossa,then followed by the common hernia type. The narrowest posterior cranial fossa was the Basilar-type CM. Posterior fossa narrowing in the CM patients was mainly to narrow transverse diameter and the depth of postertior cranial fossa.Anteroposterior diameter of the posterior cranial fossa was not significantly narrowing.Part 2 Comparing iconography study of MRI of coronal view and axial view for diagnostic value of Arnold-Chiari malformationObjective: To compare head and neck MRI sagittal images with coronal and axial images and to value the coronal and axial images for diagnosing of Arnold-Chiari malformations.Methods: 33 patients with Chiari malformation were scaned with head or head and neck axial, sagittal and coronal MRI. compression of the medulla oblongata in images of different azimuth was graded and assessed, the classification results of axial, coronal and sagittal images were compared. The extent of tonsillar herniation in coronal and sagittal images was measured and compared. The statistics of the above results were got by means of paired t test to compare whether axial and coronal measurements and grading results were different from the sagittal results.Results: The extent of cerebellar tonsillar herniation in coronal and sagittal image of the 13 patients were measured: There were no significant difference on the extent of right tonsillar herniation on sagittal and coronal images,t = 1.369, P≥0.05.There was no significant difference in the extent of left tonsillar herniation, t=1.301,P≥0.05. Medullary pressure rating results:Sagittal and axial medullary pressure rating of the paired t test, t =- 0.702, P≥0.05; sagittal and coronal medullary pressure rating of paired t test, t = 2.739, P <0.05. Axial and coronal images medullary pressure rating of paired t test, t = 2.739, P <0.05. It showed that there were no significant difference between axial and sagittal images in the observation of the medulla oblongata pressed, but coronal images in the display of the medulla oblongata compression were significantly different.Of the 33 cases of patients, left tonsillar hernia was more than right in 17 cases, and 1 case was bilateral tonsillar hernia symmetrically.Conclusion: MRI axial and coronal images had a certain reference value in the diagnosis of CM.Axial images had advantages in showing medullary compression.Coronal images have the least effectiveness in the medullary compression. On the coronal and sagittal images,the extent of cerebellar tonsillar herniation was not significantly different.Part 3 Comparison between images and clinical symptoms in Arnold-Chiari malformationObjective: To observe and analyze t he MRI i maging performance of CM and clinical data collected to compare patients with different clinical manifestations of their similarities and differences in images; to determine the role of imaging in the evaluation of patients with clinical manifestations.Methods: Complete data of clinical and imaging on 36 patients with primary Chiari malformation was collected in this study. Statistics of the number of patients with cerebellar damage symptoms ,brainstem compression or cranial nerves pulled symptoms, syringomyelia symptoms and symptoms of suspicious increased intracranial pressure was done. The level of the cerebellar tonsillar herniation in cerebellar impaired patients was compared with non-impaired. The medullary pressed rating between cranial nerves pulled patients with out the symptoms was compared. Statistics of the ratio of suspicious intracranial hypertension in patients with hydrocephalus was done.In the patients with spinal cord injuries was worked out.Results: There were eight cases with the performance of increased intracranial pressure.Brainstem or cranial nerve damaged performance was in 2 cases.There were 20 cases were with spinal cord damaged.The degree of tonsillar herniation in CM patients with cerebellar dysfunction was greater than without cerebellar damaged symptoms, Z =- 2.970, P≤0.05 (P = 0.03).There was no significant difference in medullary pressed rating between brainstem pressed and patients without it Z=-1.38,P≥0.05(P=0.17).There were 8 cases with symptoms of increased intracranial pressure, but MRI showed that only three cases of hydrocephalu(s37.5%).20 cases of spinal cord injuries, there were 16 cases of syringomyelia(80%).Conclusion: The CM of brain imaging manifestation and clinical symptoms have a certain relevance. The degree of tonsillar herniation in patients with cerebellar damaged was greater than which without dizziness, indicates that the more serious tonsil of cerebellum herniation,it is more likely to result in the Vestibular-cerebellum contact fiber damaged,and dizziness as a result. The relationship of brainstem damaged symptoms and the severity of the medulla oblongata compression, CM patients with headache and hydrocephalus, need increase sample capacity to research. Symptoms of spinal cord injuries may not have the performance of syringomyelia in imaging. |
