Modality | Example tracers/sequence | Observation(s) | Analysis | Accessibility | Cost | Suitability for screening |
---|---|---|---|---|---|---|
SPECT | 123I-β-CIT 123I-FP-CIT | Loss of binding in striatum | Visual inspection, quantification | ++ | +++ | +++ |
TCS | 2–3.5 Hz transducer | Hyperechogenicity in the region of the substantia nigra | Visual inspection, quantification | ++++ | + | +++ |
PET | 18F-dopa 18F-FDG | Loss of binding in striatum May help differentiate atypical PD | Visual inspection, quantification | ++ | ++++ | + |
MRI | Traditional (T1& T2), T2/T2* (gradient echo), DTI, spin echo, fMRI | Numerous reported, none established | Visual inspection, quantification | +++ | ++ | ++ |
MIBG | 123I-meta-iodobenzylguanidine | Low heart-to-mediastinum ratio | Visual inspection, quantification | ++ | ++ | ++ |
Accessibility, cost and suitability for screening are estimated semiquantitatively on a four-point relative scale with + lowest and ++++ highest.
DTI, diffusion tensor imaging; FDG, fludeoxyglucose; fMRI, functional MRI; Hz, hertz; MIBG, metaiodobenzylguanidine; PET, positron emission tomography; SPECT, single photon emission computed tomography; TCS, transcranial sonography.