|Are there any contrast volume limitations for the use of IV contrast?|
Indeed there is and here are some rules for Omnipaque and Visipaque courtesy of Rich Vitti MD from GE Healthcare.
The recommended doses of Omnipaque™1 and Visipaque™2 for CT body imaging are:
The maximum total doses of iodine are as follows:
GE Healthcare does not recommend the use of its products outside of the package labeling. Please refer to the package insert for full prescribing information.
Please keep in mind that the doses described below may not have been approved or cleared by the FDA.
Traditionally contrast dose for adult body CT is given in ranges of 50ml – 200ml, depending on procedure (hepatic, renal…) and iodine concentration (270mgI/ml to 400 mgI/ml). With increasing awareness of CIN and radiation dose, the trend has started to shift toward contrast dose by body weight. Some device manufacturers like Medrad (P3T) have introduced power injectors that follow a dose by weight protocol. There are a few studies published on weight-based dose for adults. Below are several examples.
Yanaga gives recommendations for specific exams:
Ichikawa recommends the following for hepatic imaging:
Exceptional patients: with severe cardiac dysfunction/abnormal circulation (we recommend a use of double arterial-phase imaging or any bolus tracking techniques, such as manual mini-bolus or automatically computer-assisted bolus tracking techniques).
Megibow7 recommends the following for abdominal CT:
Weight-based dose of 1.5ml/kg for most patients
1. Omnipaque™ prescribing information.
2. Visipaque™ prescribing information.
3. Yanaga Y, Awai K, Nakaura T, Namimoto T, et al. Optimal contrast dose for depiction of hypervascular hepatocellular carcinoma at dynamic CT using 64-MDCT. AJR. 2008;190:1003-1009.
4. Yanaga Y, Awai K, Nakaura T, Oda S, et al. Effect of contrast injection protocols with dose adjusted to the estimated lean patient body weight on aortic enhancement at CT angiography. AJR. 2009;192:1071-1078.
5. Yanaga Y, Awai K, Nakayama Y, Nakaura T, et al. Páncreas: Patient body weight-tailored contrast material injection protocol versus fixed dose protocol at dynamic CT. Radiol. 2007;245:475-482.
6. Ichikawa T, Erturk SM, Araki T. Multiphasic contrast-enhanced multidetector-row CT of liver: Contrast-enhancement theory and practical scan protocol with a combination of fixed injection duration and patients’ body-weight-tailored dose of contrast material. EJR. 2006;58:165-176.
7. Megibow AJ, Jacob G, Heiken JP, Paulson EK, et al. Quantitative and qualitative evaluation of volume of low osmolality contrast medium needed for routine helical abdominal CT. AJR. 2001;178:583-589.