Prospective multicenter study on personalized and optimized MDCT contrast protocols: results on liver enhancement

Area of Science:

• Radiology
• Medical Imaging
• Contrast Media

Background:

• Optimizing contrast media (CM) protocols in liver CT is crucial for diagnostic accuracy.
• Standardized protocols may not provide uniform enhancement across diverse patient populations.
• Personalized dosing based on body composition can improve image quality and reduce CM volume.

Purpose of the Study:

• To establish a personalized and optimized contrast injection protocol for liver CT.
• To achieve uniform and diagnostically optimal liver parenchymal enhancement in a large multicenter study population.
• To compare different contrast dosing strategies, including fixed volume and weight-based adjustments.

Main Methods:

• Prospective assignment of 692 patients to four contrast media (CM) protocols: G1 (fixed volume), G2 (total body weight), G3 (fat-free mass - FFM, higher dose), and G4 (FFM, lower dose).
• Measurement of liver parenchymal enhancement (CT number change) and enhancement variability (IQR) by radiologists.
• Statistical comparison of enhancement levels, iodine dose, and variability across protocols using Kruskal-Wallis and Mann-Whitney U tests (p < 0.005).

Main Results:

• Protocol G4 (600 mgI/kg FFM) achieved the target enhancement of 53.2 HU, significantly lower than other groups (p < 0.001).
• Liver enhancement variability (IQR) was lowest in G4 (14.5 HU), indicating improved uniformity.
• G4 demonstrated a significantly lower median iodine dose (26.0 gI) compared to G3 (33.9 gI), G2 (38.8 gI), and G1 (37 gI) (p < 0.001).

Conclusions:

• A contrast protocol based on 600 mgI/kg FFM provides diagnostically optimized liver enhancement and improved uniformity.
• Fat-free mass is a suitable parameter for personalizing contrast dosing in liver CT.
• This FFM-based protocol is recommended for diagnostic oncology follow-up liver CT examinations, reducing iodine load.