Morphological Measurement Of Mri And Assessment Of Its Diagnostic Value For Clinical Subtypes Of Progressive Supranuclear Palsy

Objective To study the magnetic resonance imaging morphometrical features of progressive supranuclear palsy（PSP）and its clinical subtypes,and to explore the value of image morphometry indexes in the differential diagnosis of PSP.Methods Fifty-four patients with PSP,including 18 cases of Richardson’s syndrome（PSP-RS）,19 cases of Parkinson’s syndrome（PSP-P）and 17 cases of progressive frozen gait（PSP-PGF）were recruited.In addition,25 patients with multiple system atrophy-Parkinson’s syndrome（MSA-P）and 38 patients with idiopathic Parkinson’s disease（PD）and 40 age and sex matched healthy controls（HC）designated as control groups were also included for comparison with PSP group.MRI morphological parameters,including midbrain area-to-pons area ratio（M/P）,magnetic resonance parkinsonism index（MRPI,MRPI2.0）,width ratio of middle cerebellar peduncle to superior cerebellar peduncle（MCP/SCP）,midbrain-to-pons ratio（MTPR）,cerebral peduncle angle（CPA）were measured and compared between groups.Receiver operating characteristic curve（ROC）analyses was performed to assess the accuracy of these imaging indicators in the diagnosis as well as differential diagnosis of PSP or its subtypes from PD or MSA-P.Results Compared with MSA-P,PD or HC group,PSP group or its subgroups showed significantly higher MRPI and MRPI2.0 but lower M/P and MTPR（P<0.05 ～P<0.001）.The differences of MCP/SCP and CPA were variable between PSP or its subgroups and control groups.The MCP/SCP was higher in PSP group in general or PSP-RS subgroup compared with control groups（P<0.05 ～ P<0.001）,whereas PSP-P subgroup had statistically higher MCP/SCP than MSA-P group or HC group but not PD group,this indactor was higher in PSP-PGF subgroup than MSA-P group（P<0.01 ～ P<0.001）.CPA was significantly greater in PSP group（pooled cases）and PSP-PGF subgroup compared with PD or HC group（P<0.005 ～ P<0.001）,this index was greater in PSP-P or PSP-PGF subgroup than HC group（P<0.05）,while CPA of PSP and its subgroups was not significantly distinct from that of MSA-P group（P>0.05）.No significant difference was identified among PSP subtypes with regard to the MRI morphometric indexes assessed in the present study.ROC analyses demonstrated that MTPR was the optimal index in diagnosing PSP and PSP-PGF,while MRPI was the best indicator in diagnosing PSP-RS and PSP-P with AUC more than 0.90.Moreover,PSP and its subtypes are best distinguished from MSA-P or PD by MTPR.None of the morphological parameters displayed AUC,sensitivity and specificity which may be useful in discriminating PSP subtypes.Conclusion MRI morphological measurements are of great value in the diagnosis of PSP and its subtypes,and also useful in the differential diagnosis of among PSP,MSA-P and PD,but the best parameters varied according to the specific application fields.In addition,it is insufficient for discriminating between various PSP subtypes.