Abdominal Multidetector CT in Patients with Varying Body Fat Percentages: Estimation of Optimal Contrast Material Dose
- 1 December 2008
- journal article
- Published by Radiological Society of North America (RSNA) in Radiology
- Vol. 249 (3), 872-877
- https://doi.org/10.1148/radiol.2492080033
Abstract
Purpose: To determine if contrast material dose for abdominal multidetector computed tomography (CT), as determined by using body weight (BW), overestimates the amount of contrast material required in heavier patients. Materials and Methods: Institutional review committee approval and patients' written informed consent were obtained. CT images of the abdomen were obtained by using 2 mL per kilogram of BW of intravenous contrast material (300 mg/mL iodine) injected at 4 mL/sec in 161 consecutive patients (age range, 28–90 years; mean age, 63 years; 95 men, 66 women). CT scans were initiated 45 and 150 seconds after aortic enhancement increased by 50 HU. The patients were divided into low (37–54 kg) and high (55–75 kg) BW groups. The ΔHU/I, where ΔHU is change in CT number and I is iodine dose in grams, and adjusted maximum hepatic enhancement (ΔHU/[I/kg]) were assessed for correlation with BW, body mass index (BMI), and body fat percentage (BFP) by using linear regression. Results: ΔHU/I correlated (P < .001) inversely with BW in the aorta (r = −0.78) and liver (r = −0.80) and with BMI in the aorta (r = −0.59) and liver (r = −0.61) on portal venous phase images. Regression formula for the low BW group was ΔHU/I = 4.1 − .044 · BW (P < .001) and for the high BW group was ΔHU/I = 2.7 − .017 · BW (P < .001), suggesting that the amount of contrast material required with increased BW is less in the high BW group. Adjusted maximum hepatic enhancement directly correlated with BFP (r = 0.25, P < .01). Conclusion: Excessive contrast material may inadvertently be given in heavier patients when the dose is determined by patient BW. Contrast material dose may need to be tailored in individual patients by using BFP. © RSNA, 2008Keywords
This publication has 20 references indexed in Scilit:
- MDCT of the Liver and Hypervascular Hepatocellular Carcinomas: Optimizing Scan Delays for Bolus-Tracking Techniques of Hepatic Arterial and Portal Venous PhasesAmerican Journal of Roentgenology, 2006
- Detection of liver metastases under 2 cm: comparison of different acquisition protocols in four row multidetector-CT (MDCT)European Radiology, 2005
- MDCT of benign liver tumors and metastases.European Radiology, 2003
- Technical ExhibitionEuropean Radiology, 2003
- Multi–Detector Row Helical CT in Preoperative Assessment of Small (≤1.5 cm) Liver Metastases: Is Thinner Collimation Better?Radiology, 2002
- Aortic and Hepatic Enhancement and Tumor-to-Liver Contrast: Analysis of the Effect of Different Concentrations of Contrast Material at Multi–Detector Row Helical CTRadiology, 2002
- Hepatic Metastases from Colorectal Cancer: Preoperative Detection and Assessment of Resectability with Helical CTRadiology, 2001
- Abdominal Helical CT: Evaluation of Optimal Doses of Intravenous Contrast Material—A Prospective Randomized StudyRadiology, 2000
- Hepatic helical CT: effect of reduction of iodine dose of intravenous contrast material on hepatic contrast enhancement.Radiology, 1995
- Contrast-enhanced spiral CT of the liver: effect of different amounts and injection rates of contrast material on early contrast enhancement.American Journal of Roentgenology, 1994