Contrast medium injection protocol adjusted for body surface area in combined PET/CT

OBJECTIVES: To evaluate the effect of contrast medium dose adjustment for body surface area (BSA) compared with a fixed-dose protocol in combined positron emission tomography (PET) and computed tomography (CT) (PET/CT). METHODS: One hundred and twenty patients were prospectively included for (18)F-2-deoxy-fluor-glucose ((18)F-FDG)-PET/CT consisting of a non-enhanced and a venous contrast-enhanced CT, both used for PET attenuation correction. The first 60 consecutive patients received a fixed 148-ml contrast medium dose. The second 60 patients received a dose that was based on their calculated BSA. Mean and maximum standardised FDG uptake (SUVmean and SUVmax) and contrast enhancement (HU) were measured at multiple anatomical sites and PET reconstructions were evaluated visually for image quality. RESULTS: A decrease in the variance of contrast enhancement in the BSA group compared with the fixed-dose group was seen at all anatomical sites. Comparison of tracer uptake SUVmean and SUVmax between the fixed and the BSA group revealed no significant differences at all anatomical sites (all P > 0.05). Comparison of the overall image quality scores between the fixed and the BSA group showed no significant difference (P = 0.753). CONCLUSIONS: BSA adjustment results in increased interpatient homogeneity of contrast enhancement without affecting PET values. In combined PET/CT, a BSA adjusted contrast medium protocol should be used preferably. KEY POINTS : * Intravenous contrast medium is essential for many applications of PET/CT * Body surface area adjustment of contrast medium helps standardise contrast enhancement * Underdosing or overdosing of contrast medium will be reduced * PET image quality is not influenced * BSA adjusted contrast medium protocol should be used preferably in combined PET/CT.