Evaluation of radiation efficiency of dual source high-pitch (DSHP) chest CT in
comparison to single source technique with special regards to individual
patient anatomy. Methods: 150 consecutive patients who underwent chest CT with
automated tube current modulation were evaluated retrospectively and divided
into three study groups, each with an equal quantity of 50 patients (DSHP vs.
single source 128 slices vs. single source 16 slices). By using a dedicated
workstation, volumetric analyses of each of the scanned anatomic area were
performed and correlated to the individual dose length product (DLP). The
calculated result was defined as dose efficiency. Results: DLP was 203 mGycm
(DSHP), vs. 269 mGycm (single source) vs. 273 mGycm (16 slice CT). The total
patient volume was lowest in the dual source group with 18956.3 cm3 (vs. 22481.2 cm3 vs. 22133.8 cm3). With regards to the
DLP, the calculated dose efficiency of dual source CT was better than the 128
slice CT (p = 0.045) and the 16 slice CT (p < 0.01). Conclusions: DSHP CT
has considerably better dose efficiency compared to 16 slice CT. Compared to
128 slice single source technique, the high-pitch mode does not cause any dose
penalty when performing chest CT.