Patients With Multiple Trauma Receive Less Radiation Exposure When Experimental Protocol Added to Whole-Body CT Scanning

March 2, 2019

By Chris Berrie

VIENNA, Austria -- March 1, 2019 -- Patients with multiple trauma receive significantly lower radiation exposure (and comparable image quality) when biphasic injection protocols and adaptive statistical iterative reconstruction-V (ASiR-V) are added to whole-body computed tomography (WBCT), according to results of a randomised, controlled study presented here at the European Congress of Radiology (ECR).

“The trauma patient is still exposed to a considerable radiation dose, with some published reports of 30 mSv for a single WBCT scan,” explained Mustafa Elmansy, MD, MSc, Mansoura University, Mansoura, Egypt, speaking here on February 27.

Dr. Elmansy and colleagues evaluated dose savings and image quality for implementing ASiR-V according to a WBCT biphasic injection protocol for these patients with severe trauma, compared with a conventional WBCT protocol featuring separate arterial and venous phase acquisitions.

Patients receiving the conventional WBCT (n = 50; mean age, 32.5 years; male), received a non-contrast CT scan for brain and cervical spine, followed after 15 seconds by a contrast-enhanced arterial-phase scan of the thorax and abdomen (90 mL, 4 mL/second), followed after 45 seconds by a venous scan, followed after 10 minutes by a delayed scan of the abdomen and pelvis.

Patients receiving the experimental WBCT (n = 50; mean age, 35.9 years; male, 82%) received a biphasic injection protocol of the non-contrast CT scan for brain and cervical spine, followed after 35 seconds by a biphasic injection for 1-step arterio-venous scan of the chest, abdomen and pelvis (50 mL, 4 mL/second; 15 second delay; 40 mL, 4 mL/second), followed after 10 minutes by a delayed scan of the abdomen and pelvis.

Image quality was assessed on a 5-grade scale, from non-diagnostic (grade 1) to optimal vascular opacification and parenchymal enhancement (grade 5). Image artefacts were also graded, from affecting diagnostic information (grade 1) to the absence of artefacts (grade 4).

Compared with the conventional protocol, the experimental protocol required a significantly lower dose-length product, which is a measure of CT-tube radiation output/exposure (2202.3 vs 1485.8 mGy.cm; 32.5% reduction; PPP = .089).

Overall, there were no significant differences between the measured Hounsfield attenuation values for the 2 protocols, although the experimental protocol scored significantly lower for liver (P = .007) and higher for spleen and right and left kidneys (PP = .003, P = .002).

For image quality and artefacts, the researchers observed no significant differences across these 2 protocols, although Dr. Elmansy noted, “The conventional procotol scored relatively higher grades.”

He added, however, that the “whole-body CT scans using biphasic injection protocols carry less radiation dose, which is vital in this predominantly young cohort of patients.”

Multiple trauma implies the presence of 2 or more separate injuries endangering a patient’s life. Traumatic injury is a leading cause of morbidity and permanent disability, and is the main cause of death in people under 45 years of age. For initial trauma management of this predominantly young age group, WBCT represents an important diagnostic tool.

Standardised WBCT has been shown to clearly improve the survival of patients who have undergone severe trauma.

The European Congress of Radiology is sponsored by the European Society for Radiology.

[Presentation title: Whole-body CT using biphasic injection protocol with adaptive statistical iterative reconstruction-V (ASiR-V) in multi-trauma patients: impact on dose reduction and image quality. Session SS217, Abstract B-0100]