Split-bolus technique of contrast medium administration used in whole body CT examination of patient with polytrauma
Abstract
Objective: The possibilities of CT examinations in patients with multiple trauma are: two-phase, or single-phase CT examination, after a single-bolus contrast medium (CM) administration; and a single-pass CT examination after multiphasic CM administration, also called "split-bolus technique" (SB). This article compares few protocols and seeks an optimal diagnostic quality.
Methods: Five patient groups were created. Group A and B underwent a CT examination after administration of single bolus of CM, then group A underwent a two-phase examination in arterial and venous phase and group E underwent single-phase examination.
Groups C, D and E underwent single-phase CT examination with split-bolus technique of CM administration. The CM volume of 100 ml and the concentration of 350 mgI/ml was used in all groups.
The groups were statistically evaluated. Results: There was a significant difference achieved in the density measured in arteries between group A vs. groups B-E.
The value of 185 HU was exceeded in all observed reference regions, with the only exception in the pelvic arteries in group C. A significant difference was found in a saturation of the hepatic parenchyma between groups A vs. groups B-E.
There was an increase of measured densities in parenchymal organs, when the saline flush after first CM bolus was used. Comparing densities in the liver and the spleen parenchyma, there was no significant difference between groups C-E vs.
B, although in group B the densities were lower by 6-14 HU. Conclusion: We achieved a good image quality in all SB protocols.
Use of SB protocols brings a significant reduction of radiation dose along with a smaller CM volume compared to previously published SB protocols. The singlephase CT examination after single bolus of CM didn't achieve the diagnostic quality demanded in examinations of patients with trauma.