Use of fuzzy edge single-photon emission computed tomography analysis in definite Alzheimer's disease - a retrospective study

We propose a new method of SPECT data analysis. The method is based on a combination of parietal lobe selection (as regions-of-interest (ROI)), 3D fuzzy edge detection, and 3D watershed transformation. We applied the algorithm to three-dimensional SPECT images of human brains and compared the number of watershed regions inside the ROI between AD patients and controls. The Student's two-sample t-test was used for testing domain number equity in both groups.AD patients had a significantly reduced number of watershed regions compared to controls (p < 0.01). A sensitivity of 94.1% and specificity of 80% was obtained with a threshold value of 57.11 for the watershed domain number. The narrowing of the SPECT analysis to parietal regions leads to a substantial increase in both sensitivity and specificity.Our non-invasive, relatively low-cost, and easy method can contribute to a more precise diagnosis of AD.Alzheimer's disease (AD) is the most common neurodegenerative dementia. Diagnostic criteria are based mainly on clinically altered cognition. Early diagnosis of AD is crucial for maximizing treatment benefits. Neuroimaging may be helpful in increasing diagnostic precision, but correlations between localized atrophy, mainly in the temporal regions, on MRIs, and AD pathology are still controversial, and promising new techniques like PET amyloid imaging are not in routine use. Low beta-amyloid and elevated tau protein levels in cerebrospinal fluid have been correlated with AD at a sensitivity of 85-94% and a specificity of 83-100% [1]. However, other studies have not been able to confirm these results and widespread consensus is lacking regarding its utility in everyday practice [2].Single photon emission computerized tomography (SPECT) is a widely used diagnostic method based on analysis of regional cerebral blood flow (rCBF); with restricted rCBF considered to reflect hypometabolism and consequently hypofunction. Typical SPECT AD patterns show reduced rCBF in both tempora