Lean body weight versus total body weight to calculate the iodinated contrast media volume in abdominal CT: a randomised controlled trial

Abstract

Objectives Iodinated contrast media (ICM) could be more appropriately dosed on patient lean body weight (LBW) than on total body weight (TBW). Methods After Ethics Committee approval, trial registration NCT03384979, patients aged ≥ 18 years scheduled for multiphasic abdominal CT were randomised for ICM dose to LBW group (0.63 gI/kg of LBW) or TBW group (0.44 gI/kg of TBW). Abdominal 64-row CT was performed using 120 kVp, 100–200 mAs, rotation time 0.5 s, pitch 1, Iopamidol (370 mgI/mL), and flow rate 3 mL/s. Levene, Mann–Whitney U, and χ2 tests were used. The primary endpoint was liver contrast enhancement (LCE). Results Of 335 enrolled patients, 17 were screening failures; 44 dropped out after randomisation; 274 patients were analysed (133 LBW group, 141 TBW group). The median age of LBW group (66 years) was slightly lower than that of TBW group (70 years). Although the median ICM-injected volume was comparable between groups, its variability was larger in the former (interquartile range 27 mL versus 21 mL, p = 0.01). The same was for unenhanced liver density (IQR 10 versus 7 HU) (p = 0.02). Median LCE was 40 (35–46) HU in the LBW group and 40 (35–44) HU in the TBW group, without significant difference for median (p = 0.41) and variability (p = 0.23). Suboptimal LCE (< 40 HU) was found in 64/133 (48%) patients in the LBW group and 69/141 (49%) in the TBW group, but no examination needed repeating. Conclusions The calculation of the ICM volume to be administered for abdominal CT based on the LBW does not imply a more consistent LCE.

Lean body weight‐adjusted intravenous iodinated contrast dose for abdominal CT in dogs reduces interpatient enhancement variability while providing diagnostic quality organ enhancement

“…Reduced variability in organ enhancement seen with LBW dosing of CM may also prove beneficial for future studies relying on quantification of CE differences to classify disease types and presents an avenue for further investigation. The relationship between organ enhancement and CM dose seems to not be simply linear, however, with hidden compensating effects proposed in the human literature 25 . Future larger studies are needed to determine the ideal CM dose per LBW to achieve adequate liver enhancement in dogs while reducing the overall iodine load and achieving satisfactory image quality.…”

“…The relationship between organ enhancement and CM dose seems to not be simply linear, however, with hidden compensating effects proposed in the human literature. 25 Future larger studies are needed to determine the ideal CM dose per…”

“…26 In the study by Zanardo and co-workers, approximately half of the patients had a liver CE below 40 HU; however, they were considered diagnostic by radiologists. 25 This was thought to be due to technological improvements in both CT hardware and software that decreased not only the ionizing radiation dose but also the dose of CM needed for a diagnostic examination, and the authors suggested that the threshold of 50 HU for sufficient liver CE should be reconsidered. 25 In people, it was reported that approximately 0.5 g iodine per kg of TBW is required to achieve an average 50 HU increase in CE in the liver.…”

“…25 This was thought to be due to technological improvements in both CT hardware and software that decreased not only the ionizing radiation dose but also the dose of CM needed for a diagnostic examination, and the authors suggested that the threshold of 50 HU for sufficient liver CE should be reconsidered. 25 In people, it was reported that approximately 0.5 g iodine per kg of TBW is required to achieve an average 50 HU increase in CE in the liver. 27 In the present study, this dose was only achieved in three of the 12 dogs when the dose was adjusted to LBW.…”

Individualized Contrast Media Application Based on Body Weight and Contrast Enhancement in Computed Tomography of Livers without Steatosis

“…In the literature, different contrast media protocols have been described to achieve homogenous attenuation between patients [ 1 , 2 ]. Some advocate the use of fixed or semi-fixed protocols [ 5 ], whilst others have advocated the use of personalized protocols based on the total body weight (TBW) [ 1 , 6 , 7 , 8 ], lean body weight (LBW) [ 9 , 10 , 11 , 12 , 13 , 14 , 15 ], percentage of body fat [ 16 ], or body surface area [ 17 , 18 ]. Thus, there is no consensus on what protocol is best to use for what types of patients.…”