Fig. 8.

Hypothetical illustration of the possible time- and age-related relationship among arterial wall FDG uptake, NaF uptake, and CT-visible calcification. The courses in childhood and very high ages are unknown. FDG uptake may be a frequently occurring repetitive process throughout life in response to minor or major arterial injuries [44]. By targeting microcalcification [17], NaF appears to be a more persistent marker of early phase atherosclerosis [4, 15, 24, 30, 36] and, through surface adsorption to macrocalcification [17], to a lesser degree also of still ongoing calcification in CT-visible calcifications [24]. The three processes follow different patterns, a slow and protracted increase of FDG uptake, a similarly early in life occurring NaF uptake that tends to persist and increase for some age decades until it decreases when macrocalcification grows and stabilizes, and finally, and in contrast, CT-detectable calcification that appears later in life and continues with aging (illustration by Dr. Reza Piri, Dept. of Nuclear Medicine, Odense University Hospital, Odense, Denmark)