Andreu F Costa1, Kris Peet2, Mohamed Abdolell2. 1. Department of Diagnostic Radiology, Queen Elizabeth II Health Sciences Centre and Dalhousie University, Victoria General Building, 3rd floor, 1276 South Park Street, Halifax, NS B3H 2Y9, Canda. Electronic address: andreufcosta@gmail.com. 2. Department of Diagnostic Radiology, Queen Elizabeth II Health Sciences Centre and Dalhousie University, Victoria General Building, 3rd floor, 1276 South Park Street, Halifax, NS B3H 2Y9, Canda.
Abstract
RATIONALE AND OBJECTIVES: To compare the magnitude and interpatient variability in normalized mean hepatic enhancement (MHE) indices when dosing contrast media (CM) according to total body weight (TBW) and lean body weight (LBW). MATERIALS AND METHODS: This ethics-approved stratified randomized controlled study allocated 280 outpatients for abdominal Computed Tomography (CT) between February-November 2018 to TBW- or LBW-dosing using computer-generated tables. CTs were acquired in portal venous phase after fixed 35-second injection of Iohexol 350. Patients with missing precontrast image, incorrect dose, or chronic kidney, liver or heart disease were excluded. The number of included patients and CM doses were: TBW arm, 51 women and 60 men, 1.22 mL/kg; LBW arm, 59 women, 1.66 mL/kg LBW, and 59 men, 1.52 mL/kg LBW. Liver attenuations were obtained from regions of interest. Values and standard deviations in MHE indices normalized to iodine dose (MHE/I) and iodine dose per kg TBW (aMHE = MHE/[I/TBW]) were compared (unpaired t tests and F-tests). RESULTS: Cohorts were similar in age, sex, TBW, and LBW. TBW groups received more CM than LBW groups: men, 106.5 ± 20 versus 98.4 ± 11 mL, p = 0.007; women, 93.7 ± 20 versus 77.5 ± 11 mL, p < 0.0001. TBW and LBW groups showed no significant difference in MHE/I (women, 1.75 ± 0.5 versus 1.86 ± 0.6 HU/g, p = 0.31; men, 1.53 ± 0.4 versus 1.52 ± 0.4 HU/g, p = 0.90) or aMHE (women, 0.03 ± 0.01 versus 0.03 ± 0.01 HU/g/kg, p = 0.25; men, 0.02 ± 0.01 versus 0.02 ± 0.01 HU/g/kg, p = 0.52). Variances in MHE/I and aMHE were not significantly different for all groups (p > 0.05). CONCLUSION: TBW- and LBW-based CM dosing yield a similar magnitude and interpatient variability in normalized MHE indices at routine abdominal CT.
RCT Entities:
RATIONALE AND OBJECTIVES: To compare the magnitude and interpatient variability in normalized mean hepatic enhancement (MHE) indices when dosing contrast media (CM) according to total body weight (TBW) and lean body weight (LBW). MATERIALS AND METHODS: This ethics-approved stratified randomized controlled study allocated 280 outpatients for abdominal Computed Tomography (CT) between February-November 2018 to TBW- or LBW-dosing using computer-generated tables. CTs were acquired in portal venous phase after fixed 35-second injection of Iohexol 350. Patients with missing precontrast image, incorrect dose, or chronic kidney, liver or heart disease were excluded. The number of included patients and CM doses were: TBW arm, 51 women and 60 men, 1.22 mL/kg; LBW arm, 59 women, 1.66 mL/kg LBW, and 59 men, 1.52 mL/kg LBW. Liver attenuations were obtained from regions of interest. Values and standard deviations in MHE indices normalized to iodine dose (MHE/I) and iodine dose per kg TBW (aMHE = MHE/[I/TBW]) were compared (unpaired t tests and F-tests). RESULTS: Cohorts were similar in age, sex, TBW, and LBW. TBW groups received more CM than LBW groups: men, 106.5 ± 20 versus 98.4 ± 11 mL, p = 0.007; women, 93.7 ± 20 versus 77.5 ± 11 mL, p < 0.0001. TBW and LBW groups showed no significant difference in MHE/I (women, 1.75 ± 0.5 versus 1.86 ± 0.6 HU/g, p = 0.31; men, 1.53 ± 0.4 versus 1.52 ± 0.4 HU/g, p = 0.90) or aMHE (women, 0.03 ± 0.01 versus 0.03 ± 0.01 HU/g/kg, p = 0.25; men, 0.02 ± 0.01 versus 0.02 ± 0.01 HU/g/kg, p = 0.52). Variances in MHE/I and aMHE were not significantly different for all groups (p > 0.05). CONCLUSION:TBW- and LBW-based CM dosing yield a similar magnitude and interpatient variability in normalized MHE indices at routine abdominal CT.