Fig. 1.

Temporal characterisation of atherosclerotic micro-calcification in ApoE^−/− HCD atherosclerosis model using [¹⁸F]NaF PET/CT. (A) In vivo [¹⁸F]NaF PET/CT of the heart and aortic arch showing micro-calcification (broken circle) in the ascending portion of the aorta within the 12 week HCD cohort. (B) Quantification of the in vivo PET signal within the ascending aortic arch, n = 5–6. (C) Masson's trichrome staining within the brachiocephalic trunk indicating the presence of atherosclerotic plaques from 6 weeks on HCD, progressing to a more advanced plaque by 12 weeks HCD, n = 5–6. Scale bar = 250 µm. (D) Ex vivo [¹⁸F]NaF PET/CT showing the presence of micro-calcification (white arrow) and early macro-calcification (red arrows) mainly in the aortic arch after 12 weeks HCD. (E-F) Ex vivo PET and CT quantification confirmed this pattern, n = 5–6. All results are shown as the mean ± SEM, ŦŦŦŦ= p ≤ 0.0001 using an unpaired t-test; *=p < 0.05, **=p ≤ 0.01, ***=p ≤ 0.001 and ****= p ≤ 0.0001 using a one-way ANOVA with post-hoc Tukey’s comparison. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)