Early and correct diagnosis of Parkinson's disease (PD) is critical for patient counseling and therapeutic management. The diagnostic accuracy of transcranial sonography of substantia nigra (SN-TCS) for early stage PD patients remains controversial. Dopamine transporter (DAT) imaging is sensitive to detect presynaptic dopamine neuronal dysfunction, and has been studied as a diagnostic tool for degenerative Parkinsonism. To investigate the predictive value of SN-TCS for the DAT PET scans in clinically diagnosed early stage PD patients, we performed the SN-TCS and DAT Positron Emission Computed Tomography (PET) imaging examinations on 53 patients. Using the DAT PET results as clinical gold standard, the sensitivity and specificity of TCS was 68.75% and 40% respectively. The positive predictive value (PPV) of an abnormal TCS for an abnormal PET scan was 91.67%. However, the negative predictive value (NPV) for a normal PET scan was only 11.76%. The false negative rate was 31.25%. In 35 patients, the result of the SN-TCD was in accordance with the result of the DAT PET scan (Kappa = 0.042, P > 0.05). The consistency between SN-TCS and PET scans was poor. We conclude that SN-TCS would not be used as a diagnostic tool for early stage PD patients. Negative result of TCS could not exclude the diagnosis of PD. Further tests like DAT-PET is needed for validation. On the other hand, positive SN-TCS will reduce the added diagnostic value of a presynaptic neuronimaging scan. (C) 2014 Elsevier Ireland Ltd. All rights reserved.