PT  - JOURNAL ARTICLE
AU  - Tania Pawade
AU  - Timothy Cartlidge
AU  - David Newby
AU  - Dweck Marc
TI  - 117 Optimisation and Reproducibility of 18F-Fluoride Positron Emission Tomography and Computed Tomography in Patients with Aortic Stenosis
AID  - 10.1136/heartjnl-2016-309890.117
DP  - 2016 Jun 01
TA  - Heart
PG  - A82--A82
VI  - 102
IP  - Suppl 6
4099  - http://heart.bmj.com/content/102/Suppl_6/A82.1.short
4100  - http://heart.bmj.com/content/102/Suppl_6/A82.1.full
SO  - Heart2016 Jun 01; 102
AB  - Background 18F-Fluoride positron emission tomography (PET) and computed tomography (CT) can measure disease activity and progression in aortic stenosis. We aimed to optimise imaging methodology, analysis and scan-rescan reproducibility.Methods Fifteen patients with aortic stenosis underwent 18F-fluoride PET-CT twice within 1 month. We compared non-gated PET and non-contrast CT, with a modified approach that incorporated contrast CT and ECG-gated PET. We explored a range of image analysis techniques including estimation of blood pool activity at differing vascular sites and a most-diseased segment (MDS) approach.Results Contrast-enhanced ECG-gated PET-CT provided superior spatial localisation of 18F-fluoride uptake that permitted localisation to individual valve leaflets (Figure). Scan-rescan reproducibility was markedly improved using enhanced analysis techniques leading to a reduction in variability from 25% to <10% (tissue-to-background MDS: mean value 1.55, difference 0.05, limits of agreement -0·10 to 0·20).Abstract 117 Figure 1 Blood pool correction was performed by sampling from the right atrium instedad of the brachio-cephalic vein. 2. The most diseased segment method was used to quantify the PET signal within 2 hottest slices rather than the whole valve/ 3. Contrase CT fused with ECG-gated PET gacilitated better localization to leaflets compared to the original approach 4. Bland-Altmanplots emonstrated superior sacn-rescan reproducibility for the modified technique (2b) compared to the previous approach (2a)Conclusion Optimised 18F-fluoride PET-CT provides excellent spatial resolution and scan-rescan reproducibility. It holds major promise as a marker of disease activity in aortic stenosis and has major potential as a biomarker end-point of trials of novel therapies in aortic stenosis.