The aims of this study are: 18F-THK5351 PET(Positron Emission Tomography) can defect the tau burden in PSP(Progressive Supranuclear Palsy) and CBS (Corticobasal syndrome)correlating with the known NFT(neurofibrillary tangles) topology of those diseases, 18F-THK5351 PET will differentiate subjects with suspected tauopathy due to PSP and CBS from subjects with suspected synucleinopathy due to idiopathic PD(Parkinson's disease). The distribution of PHF(paired helical filament) tau burden will correlate with specific motor and cognitive features of PSP and CBS; and regional PHF tau burden will be associated with cortical thinning. Together, these efforts will establish the potential for developing 18F-THK5351 PET imaging as a biomarker and diagnostic tool for the parkinsonian tauopathies.

Inclusion Criteria:

1. 20 subjects with a diagnosis of PD whom must:

   • Age ranges from 20-80 years
   • Patients should be fulfilled "UK(United Kingdom ) Parkinson's Disease Society Brain Bank Criteria for the diagnosis of PD", 2.11.1 Appendix I, (27)
   • Patients who provide a written informed consent prior to study entry. If the patient is incapable of informed consent, the caregiver may consent on behalf of the patient (the patient must still confirm assent).

2. 20 subjects with a diagnosis of PSP whom must:

   • Age ranges from 20-80 years
   • Patients fulfill the criteria of NINDS-SPSP(National Institute of Neurological Disorders and Stroke / Society for PSP) clinical criteria for the diagnosis of PSP "as possible" or "probably" PSP, 2.11.2 Appendix II, (28)
   • Patients who provide a written informed consent prior to study entry. If the patient is incapable of informed consent, the caregiver may consent on behalf of the patient (the patient must still confirm assent).

3. 20 subjects with a diagnosis of CBS whom must:

   • Age ranges from 20-80 years
   • Patients should be fulfilled the "Mayo Clinic proposed criteria for the diagnosis for corticobasal syndrome" , 2.11.3 Appendix III, (29)
   • Patients who provide a written informed consent prior to study entry. If the patient is incapable of informed consent, the caregiver may consent on behalf of the patient (the patient must still confirm assent).

Exclusion Criteria:

1. Implantation of metal devices including cardiac pacemaker, intravascular metal devices.
2. Major systemic diseases including coronary arterial disease, heart failure, uremia, hepatic failure, prominent strokes, acute myocardial infarction, poorly controlled diabetes, previous head injury, intracranial operation, hypoxia, sepsis or severe infectious diseases
3. Major psychiatric disorders, drug or alcohol abuse and major depression
4. Pregnant women or breast- feeding women
5. Patients in whom MRI was contraindicated
6. History of severe allergic or anaphylactic reactions particularly to the tested drugs
7. Indication of impaired liver function as shown by an abnormal liver function profile at screening (eg. repeated values of aspartate aminotransferase [AST(aspartate aminotransferase)] and alanine aminotransferase [ALT(Alanine aminotransferase)] ≧ 3X(3 Times) the upper limit of normal values)