title: The predictive value of transcranial sonography in clinically diagnosed patients with early stage Parkinson's disease: comparison with DAT PET scans.
abstract: 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.
authors.affiliation: Department of Neurology & Brain Medical Center, the First Affiliated Hospital of Medical School of Zhejiang University, Hangzhou 310003, Zhejiang, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Liu
authors.affiliation: Department of Neurology, Beijing Tiantan Hospital & Beijing Institute For Brain Disorder of Parkinson's disease, Capital Medical University, Beijing 100050, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Neurology, Beijing Tiantan Hospital & Beijing Institute For Brain Disorder of Parkinson's disease, Capital Medical University, Beijing 100050, China.
authors.forename: Fang-Fei
authors.initials: FF
authors.lastname: Li
authors.affiliation: Department of Nuclear Medicine, No. 1 Hospital, Affiliated to General Hospital of the Chinese People's Liberation Army, Beijing 100853, China.
authors.forename: Qiao-Hong
authors.initials: QH
authors.lastname: Ou-Yang
authors.affiliation: Department of Ultrasonography, Beijing Tiantan Hospital, Capital Medical University, Beijing 100050, China.
authors.forename: Hong-Xia
authors.initials: HX
authors.lastname: Zhang
authors.affiliation: Department of Neurology, Beijing Tiantan Hospital & Beijing Institute For Brain Disorder of Parkinson's disease, Capital Medical University, Beijing 100050, China. Electronic address: happyft@sina.com.
authors.forename: Tao
authors.initials: T
authors.lastname: Feng
mesh_terms: D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology*; D050483:Dopamine Plasma Membrane Transport Proteins / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000000981:diagnostic imaging* / Q000473:pathology; D011379:Prognosis; D011877:Radionuclide Imaging; D014463:Ultrasonography
chemical_list: D050483:Dopamine Plasma Membrane Transport Proteins
keywords: Dopamine Transporter Positron Emission Computed Tomography Imaging; Parkinson's disease; Substantia nigra; Transcranial sonography