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Publication:

A comparison of Tc-99m-exametazime and I-123-FP-CIT SPECT imaging in the differential diagnosis of Alzheimer's disease and dementia with Lewy bodies (2008)

Author(s): Colloby SJ, Firbank MJ, Pakrasi SE, Lloyd JJ, Driver I, McKeith IG, Williams ED, O'Brien JT

    Abstract: Background: The aim of this study is to investigate the diagnostic value of perfusion Tc-99m-exametazime single photon emission computed tomography (SPECT) in the diagnosis of dementia with Lewy bodies (DLB) and Alzheimer's disease (AD) in comparison with dopaminergic I-123-2 beta-carbomethoxy-3 beta-(4-iodophenyl)-n-(3-fluoropropyl) nortropane (FP-CIT) SPECT imaging. Methods: Subjects underwent Tc-99m-exametazime scanning (39 controls, 36 AD, 30 DLB) and I-123-FP-CIT scanning (33 controls, 33 AD, 28 DLB). For each scan, five raters performed visual assessments blind to clinical diagnosis on selected transverse (99)mTc-exametazime images in standard stereotactic space. Diagnostic accuracy of Tc-99m-exametazime was compared to I-123-FP-CIT results for the clinically relevant subgroups AD and DLB using receiver operating characteristic (ROC) curve analysis. Results: Inter-rater agreement for categorizing uptake was "moderate" (mean kappa = 0.53) for Tc-99m-exametazime and "excellent" (mean kappa = 0.88) for I-123-FP-CIT For AD and DLB, consensus rating matched clinical diagnosis in 56% of cases using Tc-99m-exametazime and 84% using I-123-FP-CIT In distinguishing AD from DLB, ROC analysis revealed superior diagnostic accuracy with I-123- FP-CIT (ROC curve area 0.83, sensitivity 78.6%, specificity 87.9%) compared to occipital Tc-99m-exametazime (ROC curve area 0.64, sensitivity 64.3%, specificity 63.6%) p = 0.03. Conclusion: Diagnostic accuracy was superior with I-123-FP-CIT compared to Tc-99m-exametazime in the differentiation of DLB from AD.

    Notes: Times Cited: 0

      • Date: 27-08-2008
      • Journal: International Psychogeriatrics
      • Volume: 20
      • Issue: 6
      • Pages: 1124-1140
      • Publisher: Cambridge University Press
      • Publication type: Article
      • Bibliographic status: Published
      Staff

      Professor Ian McKeith
      Professor of Old Age Psychiatry