Radiation Dose is Reduced with a Single-Pass Whole-Body Multi–Detector Row CT Trauma Protocol Compared with a Conventional Segmented Method: Initial Experience

Abstract

Radiation dose data were collected from a calibrated multi-detector row computed tomographic (CT) scanner during trauma CT. One protocol (used with 10 case subjects) involved a single-pass continuous whole-body acquisition from cranial vertex to symphysis pubis, while the other, conventional protocol (used with 10 control subjects) involved scouting and scanning body segments (head, cervical spine, chest, abdomen, and pelvis) individually. Technical factors were kept constant within each body segment for the single-pass and the segmented protocols. Statistics included univariate analysis, two-tailed t testing to evaluate statistical significance of the summary statistic, and power and subject population contingency tables. The mean dose length product (DLP) with the single-pass protocol was 17% lower than the sum of the DLPs of each of the individual body segment scans (P <.001). Analysis of power and subject population by using a difference in mean of 500 mGy. cm and an alpha of.05 revealed a (1-beta) of higher than 0.90 for a sample of 10 patients. Thus, a whole-body single-pass trauma protocol, compared with a typical segmented acquisition protocol matched for imaging technique, resulted in reduced total radiation dose. The reduction in radiation dose is thought to represent a reduction in redundant imaging at overlap zones between body segments scanned in the segmental protocol but not in the continuous acquisition.

Dose reduction in 64-row whole-body CT in multiple trauma: an optimized CT protocol with iterative image reconstruction on a gemstone-based scintillator

“…5,23 The different scan parameters and different patient positions applied make an important contribution. Ptak et al 24 and Fanucci et al 25 have shown that a monophasic examination provides a significant dose reduction and shorter duration of the scan than a segmented scan protocol owing to missing overlap. Neither of these studies were conducted with 64-row MDCT scanners.…”

A novel multiple-trauma CT-scanning protocol using patient repositioning

“…This maneuver can even be performed using different inclination angles for each arm to minimize streak artifacts caused by arm bones being in direct opposition. The authors of another study did not reposition patients' arms to perform a whole-body single-pass trauma protocol [8]. This resulted in a reduced total radiation dose due to a reduction in redundant imaging at overlap zones between body segments, which occurs with segmental protocols.…”

“…Of all emergency conditions, the multiple-trauma patient has perhaps benefited most from the introduction of multi-row detector CT, due to shorter scan times and a high spatial resolution [5][6][7][8]. Many centers are, therefore, equipped with dedicated CT scanners to allow fast access for emergency patients, especially those with multiple trauma [9].…”

Evaluation of a Single-Pass Continuous Whole-Body 16-MDCT Protocol for Patients with Polytrauma

“…However, studies [11,19] have shown marked dose reduction (17%) with use of single-pass protocols instead of conventional segmental protocols. The reduction probably is explained by a decrease in redundant imaging.…”