Dual-source 128-slice MDCT neck: Radiation dose and image quality estimation of three different protocols

Purpose

To estimate the radiation dose and image quality of single-source (SSCT), high-pitch (HPCT), and dual-energy (DECT) protocols of a dual-source CT (DSCT) system for the examination of neck.

Materials and methods

180 patients were randomized to one of the three protocols: 60 patients (age: 55.4 ± 12 years; range: 44–84 years) were examined with a SSCT, other 60 (59.5 ± 16.4years; R: 40–85) with HPCT, and the last 60 (61.1 ± 14.9 years; R: 47–84) were examined with a DECT protocol. All examinations were performed using a DSCT system. The used protocols: Group-1 (SSCT: 120 kV; effective mAs: 185.4 ± 17.7), Group-2 (HPCT: 120 kV; eff. mAs: 97.7 ± 11.8), and Group-3 (DECT: 80 kV/140 kV with tin-filter; eff. mAs: 248.5 ± 25.7; 187 ± 21.2). A 100 ml iomeprol non-ionic contrast material was injected in to the patients during examination.

Results

Insignificant results were yielded regarding SNR and CNR between the groups (group-1 vs. 2: 0.3125, group-1 vs. 0.6W: 0.6875, group-2 vs. 0.6W: 0.3125), except DECT-80 (group-1 vs. 80 kV: 0.04289, group-2 vs. 80 kV: 0.025, group-0.6W vs.80 kV: 0.04567) and 140 kV data, moreover, qualitative analysis yielded the same results. Mean effective-dose was significantly lower (p < 0.05) in group-2 (1.06 ± 0.16 mSv) compared to group-1 (2.05 ± 0.22 mSv) or group-3 (1.76 ± 0.2 mSv). Single- and dual-energy comparison showed a significant difference (group-1 vs. 3: p = 0.00001 and group-2 vs. 3: p = 0.00001) for CTDIvol (percent difference: 16%, 64%) or DLP (PD: 15.5%, 50.5%).

Conclusion

Quantitative and qualitative analysis showed similar results for SSCT, HPCT, and DECT-0.6W datasets regarding quality. HPCT yielded lower dose compared to other groups, however, the DECT achieved a lower and significant dose difference from the SSCT protocol. HPCT and DECT can be used with similar image quality and lower radiation dose compared to SSCT for the scans and can be utilized to various clinical advantages.