Comparison of Low-Dose With Standard-Dose Multidetector CT in Cervical Spine Trauma

Abstract

BACKGROUND AND PURPOSE: The purpose of this work was to evaluate the possible use of low-dose multidetector CT (MDCT) in cervical clearance of patients with blunt trauma.

MATERIALS AND METHODS: A total of 191 patients underwent cervical spine MDCT with 6- and 16-MDCT: standard-dose (n = 51) and low-dose MDCT with tube current modulation at high (n = 70) and low (n = 70) tube voltage (kilovolts). Effective dose, image noise, and subjective image quality were calculated in all of the patients.

RESULTS: MDCT found 18 patients (9.4%) with a cervical spine fracture, 3 in the standard-dose and 15 in the low-dose group, 14 of them with unstable lesions. Tube current modulation reduced the dose by 50%–61% in all of the low-dose examinations. The mean effective dose was 3.75, 1.57, and 1.08 mSv, and mean image noise was 14.82, 17.46, and 19.72 Hounsfield units for standard dose and low dose with high and low kilovolt examinations, respectively. These differences in mean effective dose and image noise were significant between the 3 examination groups (Kruskal-Wallis test: P < .0001 and P = .0001). Evaluation of subjective image quality by 2 radiologists and 2 residents showed no significant difference in image quality score among the 3 examination groups (Kruskal-Wallis tests, P = .61, .32, .18, and .31). All of the reviewers correctly detected 18 fractures, except 1 resident, who missed 3 fractures.

CONCLUSION: Low-dose cervical spine MDCT in patients with blunt trauma gives a substantial dose reduction of 61%–71%, compared with standard-dose MDCT, with a small increase in image noise and without difference in subjective image quality evaluation.