Aims and objectives
The most important patient factors determining enhancement effect of contrast agents are weight and cardiac output [1].
Tailoring the dosage of contrast agents to individual patients is usually achieved by a linear or stepwise increase in dosage according to body weight.
This approach is imprecise,
especially for obese patients,
since adipose tissue does not contribute substantially to contrast distribution [2-4].
Axial CT images of one obese and one average patient is shown in figure 1.
Tailoring contrast agent dosage to lean body mass (LBM) is...
Methods and materials
Prior to CT venography 24 patients were weighed using a professional body composition device based on BIA.
Exclusion criteria were age < 18 years,
pregnancy,
contrast agent allergy,
severely reduced renal function (with a maximum iodine dose < 17,5 g estimated with the Omnivis calculator) or inability to give informed consent.
Measurements were conducted with a dual frequency,
BIA device (Tanita DC-430MA,
Tanita Corporation of America,
Inc.,Arlington Heights,
IL,
USA),
pairing the classic high frequency (50 kHz) with a low frequency (6,25 kHz).
The device...
Results
A total of 24 patients were included in the data analysis.
Body composition analysis,
including patient preparation,
was completed in 90 seconds or less.
Median age was 56.5 years (range: 30-87),
62% of the patients were male.
The median weight was 95 kg (range: 58-151).
Median BMI was 31.3 kg/m2 (range: 19.5-47.6).
Median LBM with the BIA device was 68.7 kg (interquartile range (IQR): 46.3-84.2).
Median LBM using the Boer formula was 65.4 kg (IQR: 48.4-81.7).
Median LBM using the James formula was 66.6 kg...
Conclusion
We found that estimation of LBM with a BIA device was easily performed in a clinical setting.
Tailoring contrast dosage to LBM is shown to reduce patient-to-patient enhancement variability,
and may improve vascular and parenchymal enhancement and lesion conspicuity [3-5].
BIA or the Boer formula may yield a more accurate estimate of LBM than the James formula in obese patients [3,
12,
13].
Our study is limited by the small number of patients,
and the lack of a reference standard measurement to which the BIA...
References
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Intravenous Contrast Medium Administration and Scan Timing at CT: Considerations and Approaches.
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The Optimal Body Size Index with which to Determine Iodine Dose for Hepatic Dynamic CT.
Radiology.
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3. Rengo M.
MDCT of liver in obese patients:evaluation of a different method to optimize iodine dose.
Abdominal Radiology.
2017.
4. Ho LM,
Nelson RC,
Delong DM.
Determining contrast medium dose and rate on basis of lean body weight: does this strategy improve patient-to-patient uniformity of hepatic...