Three-dimensional surface display of brain perfusion with 123I-IMP in Parkinson's disease

We reconstructed three-dimensional (3D) surface images from single-photon emission computed tomography (SPECT) data using N-isopropyl-p[123I]-iodoamphetamine (123I-IMP) in 27 patients with Parkinson's disease and 11 normal control subjects. The 3D reconstruction was performed using distance-shaded methods at threshold levels with an interval of 5% from 45-80%. Any area of decreased perfusion at each threshold level was visualised as a defect area by the algorithm. In nondemented patients with Parkinson's disease, perfusion defects were frequently found in the parietal cortex at a threshold value of 65%. In demented patients, perfusion defects were frequently seen at thresholds of 45-65%, and were more marked in the temporal and parietal cortex bilaterally. This suggests that dementia in Parkinson's disease is related to a reduction of perfusion in the temporoparietal cortex.