Comparative study on the diagnostic value of positron emission tomography and transcranial sonography in the diagnosis of Parkinson's disease

Abstract

To evaluate the consistency of dopamine transporter (DAT) positron emission tomography (PET) versus transcranial sonography (TCS) of Parkinson's disease (PD) patients. A total of 53 clinically diagnosed idopathic PD patients from Beijing Tiantan Hospital underwent (11)C-CFT PET and transcranial sonography (TCS). Asymmetric reduced dopaminergic function was a positive result of PET while unilateral hyperechoic area larger than 0.2 cm2 a positive result of TCS. Kappa test was used to evaluate the consistency of two methods. Among them, 36 patients (67.92%) were TCS positive while 17 patients (32.08%) TCS negative. There were 48 patients (90.57%) with positive PET whereas PET was negative for 5 patients (9.43%). TCS and PET were both positive in 33 patients (62.26%) while 2 (3.77%) yielded a double negative result. As compared with the PET results, the sensitivity, specificity, positive predictive value and negative predictive value of TCS were 68.75%, 40%, 91.67% and 11.76% respectively. For Kappa test, Kappa = 0.042, P = 0.690, P > 0.05. It inferred a poor consistency. TCS has a high predictive value for PET positive PD patients. For clinically diagnosed PD patients, a positive TCS result highly predicts PD without DAT-PET. However a negative TCS result can not rule out the possibility of PD. DAT-PET needs to be performed for further confirmation.