Visual rating and ROI-based parametric analysis of rCBF SPECT in patients with mild or questionable dementia: a comparative study.
BACKGROUND
The aim of this study was to assess the accuracy of visual image rating as compared to parametric analysis of regional cerebral blood flow (rCBF) measured with SPECT in patients referred to a memory clinic for diagnostic evaluation of cognitive symptoms.


METHODS
SPECT with (99m)Tc-HMPAO was used to determine rCBF in 47 patients and 26 healthy control subjects. The 47 patients (30 F/17 M) had a mean age of 74.6 years (range = 62-88) and mild or questionable dementia with an MMSE score of 24.8 (range = 20-30). Two experienced image readers blinded to the classifications and identity of subjects performed visual rating in consensus and the global and regional CBF patterns were evaluated and graded according to severity of hypoperfusion. Correlation coefficients were calculated using results from the parametric analyses as gold standard.


RESULTS
The sensitivity and specificity of global visual rating (normal vs. abnormal SPECT) was 92 and 86%, respectively, yielding an overall accuracy of 89% for visual rating compared to parametric analysis. The correlation between visual rating and parametric analysis was highly significant (p < 0.001).


CONCLUSIONS
Visual rating is a valid method for analyzing SPECT images in patients with mild or questionable dementia.
Høgh
Peter
P
Memory Disorders Research Group, Department of Neurology, Copenhagen University Hospital, Rigshospitalet, Neuroscience Centre, Copenhagen, Denmark. hoegh@dadlnet.dk
Teller
Ann-Sofie
AS
Hasselbalch
Steen
S
Waldemar
Gunhild
G
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D001921:Brain / Q000098:blood supply* / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000502:physiology; D003704:Dementia / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D012720:Severity of Illness Index; D015899:Tomography, Emission-Computed, Single-Photon; D014796:Visual Perception / Q000502:physiology*