Lookup NU author(s): Dr Gemma Roberts,
Dr Joseph Kane,
Dr James Lloyd,
Dr George Petrides,
Professor John O'Brien,
Professor Alan Thomas
This is the authors' accepted manuscript of an article that has been published in its final definitive form by Lippincott Williams & Wilkins, 2019.
For re-use rights please refer to the publisher's terms and conditions.
ObjectivesCardiac I-123-MIBG imaging is an established technique for the diagnosis of dementia with Lewy bodies (DLB) but various analysis methods are reported in the literature. We assessed different methods in the same cohort of subjects to inform best practice.MethodsSeventeen subjects with DLB, 15 with Alzheimer’s disease (AD) and 16 controls were included. Planar images were acquired 20 minutes and four hours after injection. Nine operators produced heart-to-mediastinum ratios (HMRs) using freehand and 6, 7 and 8cm diameter circular cardiac regions. Inter-operator variation was measured using the coefficient of variation. HMR differences between methods were assessed using ANOVA. Seven raters assessed the images visually. Accuracy was compared using ROC analysis. ResultsThere were significant differences in HMR between region methods (p=0.006). However, with optimised cut-offs there was no significant difference in accuracy (p=0.2-1.0). The sensitivity was 65% to 71% and specificity 100% for all HMR methods. Variation was lower with fixed regions than freehand (p<0.001). Visual rating sensitivity and specificity were 65% and 77% on early images and 76% and 71% on delayed images. There was no significant difference in HMR between early and delayed images (p=0.4-0.7) although a greater separation between means was seen on delayed images (0.73 vs 0.95).ConclusionsHMR analysis using a suitable cut-off is more accurate than visual rating. Accuracy is similar for all methods, but freehand regions are more variable and 6 cm circles easiest to place. We recommend calculating HMR using a 6cm circular cardiac ROI on delayed images.
Author(s): Roberts G, Kane JPM, Lloyd JJ, Petrides GS, Howe K, O'Brien JT, Thomas AJ
Publication type: Article
Publication status: Published
Journal: Nuclear Medicine Communications
Print publication date: 01/07/2019
Online publication date: 02/05/2019
Acceptance date: 16/04/2019
Date deposited: 23/04/2019
ISSN (print): 0143-3636
ISSN (electronic): 1473-5628
Publisher: Lippincott Williams & Wilkins
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