[Application of swallow tail appearance in patients with Parkinson's disease].

To evaluate the clinical value of swallow tail appearance in detecting the patient with Parkinson's disease at 3.0 T MRI.A total of 42 patients with clinical diagnosis of Parkinson's disease(PD) and 27 age-matched normal controls underwent the brain MR examination with conventional and E-SWAN sequences. Patients were divided into 4 groups based on Hoehn-Yahr stage and 2 groups according the treatment condition (treated, untreated). Substantia nigra (SN) was selected as region of interest (ROI) and observed the swallow tail appearance on magnitude imagines of E-SWAN sequence. Nonparametric test was used for comparison between patients groups and normal controls. There was statistically difference if the P value was lower than 0.05.The swallow tail appearance lost was significantly correlated with Parkinson's disease (P=0.000). The swallow tail appearance lost was not correlated with the usage of drugs(P=0.833) and Hoehn-Yahr stage(P=0.189). The sensitivity of diagnosis of PD by using the swallow tail disappearance was 95.5% (42/44), the specificity was 83.3% (25/30), the accuracy was 90.5%(67/74).Assessing the substantia nigra on E-SWAN for the typical swallow tail appearance has potential to become a new and easy applicable 3.0 T MRI diagnostic tool for PD, however, it was meaningless for prognosis and staging.