Evaluation of symptomatic and asymptomatic cm1 patients with perfusion mri and phase contrast cine MRI

CM 1 malformation is a posterior fossa abnormality which is characterized with herniation of cerebellum and cerebellar tonsils throught foramen magnum. Most of the CM1 patients are asymptomatic but they can also have mild sypmtoms at aroundage of 25-30.Variety of symptoms are believed to alternate with the degree of tonsiller herniation and CSF flow abnormalities at the cerebrospinal junction. CM1 malformation is typically diagnosed by imagining modalities such as MRI. With MR imagining evaluation of tonsiller herniation, ventricular dilatation, syringomyelia, skeletal abnormalities can be done easily. Also accompanying CSF flow abnormalities caused by compression of cerebellar tonsils can be shown with cine PC MRI and perfusion changes at the posterior fossa with DSC Perfusion MRI. Aim of this study is to evaluate perfusion changes at the posterior fossa and CSF flow abnormalies in symptomatic and asymptomatic CM1 patients. 64 CM1 patients (22 men, 42 women; meanage 35,81 years, agerange 11-72)involved in this study. 22 of the patiens were clinically symptomatic and 42 patiens were asymptomatic. Patients were staged by using CSF flow abnormalities at the level of foramen magnum with cine PC MRI findings. Stage 0 patients were includeding to radiologically asymptomatic (normal), stage 1-2 patients were includeding to radiologically symptomatic (abnormal)group. All the clinically symptomatic patiens were also radiologically abnormal. 5 of clinically asymptomatic patients (22.7 %) were radiologically abnormal. After clinical and radiological staging DSC perfusion MRI was performed to all patient groupsand at the different localizations some measurements were done at theCBV, CBF, MTT maps. With the maps in clinically symptomatic and asymptomatic patients that aquired with dynamic subsebility perfusion imagining some measurements were done. At the level of bulbus mean rCBF ve rCBV values were significantly low when compared with asymptomatic patients and there was a evident difference between twogroups (p<0.05). Measurements have been done at the level of cerebellum and supraventricular white matter in clinically symptomatic and asymptomatic patient groups. CBF, CBV, MTT ratios were compared. In the symptomaticgroup CBV bulbus/cerebellum, CBVbulbus/white matter, CBF bulbus/cerebellum and CBF bulbus/white matter ratios were significantly different compared to asymptomaticgroup (p<0.05). With the measurement aquired by using dynamic subsebility perfusion imagining at thelevel of bulbus, cerebellumandsupraventricularwhitematter, rCBV, rCBF, rMTT values were compared to each other. In the radiologically symptomatic group rCBV ve rCBF values were significantly low and different when compared to asymptomaticgroup at the level of bulbus (p<0.05). Other parameters at these three localizations were not different between two groups (p>0.05). CBF, CBV, MTT valuesaquired in radiologically symptomatic and asymptomatic patient groups at the level of bulbus, cerebellum and supraventricular white matter were compared to each other. In the symptomaticgroup CBV bulbus/cerebellum, CBV bulbus/white matter, CBF bulbus/cerebellum and CBF bulbus/white matter ratios were significantly different compared to asymptomatic patients (p<0.05). In this study we have showed that the radiologic staging may be an alternative to clinical staging in CM 1 patients. Also the difference between perfusion parameters in symptomatic and asymptomatic patients may have a role in ethiopatogenesis. In the choice of treathment the results we have reached can be usefull. Keywords: Chiari type 1 malformation, DSC perfusion MRI, PC cine MRI, Radiological staging.