Multidetector CT radiation dose optimisation in adults: short- and long-term effects of a clinical audit

Abstract

• External support through clinical audit may optimise default parameters of routine CT. • Reduction of 75th percentiles used as reference diagnostic levels is 18-75 %. • The effect of this audit is sustainable over time. • Dose savings through optimisation can be added to those achievable through CT.

Radiation Doses in Consecutive CT Examinations from Five University of California Medical Centers

“…Pantos et al (18) summarized doses from 42 published studies, reporting similar doses in the head (mean effective dose, 1.9 vs 2.0 mSv) but lower doses in the chest (mean effective dose, 7.5 vs 12 mSv) and abdomen (mean effective dose, 15 vs 17 mSv). Tack et al (17) reported audit results in Luxembourg following a nationwide dose optimization effort and also found similar doses in the head (CTDI vol , 52 vs 50 mGy) and lower doses in the chest (CTDI vol , 7 vs 12 mGy) and abdomen (CTDI vol , 10 vs 12 mGy). Stamm (16) conducted a broad review of diagnostic reference levels (set at the 75th percentile) that were generally lower than our 75th percentile in distribution.…”

“…However, few CT diagnostic reference levels in the United States are based on large numbers of actual patient examinations; many U.S. guidelines are based on selected data submitted to demonstrate a facility's best work (10)(11)(12), and these may not reflect the routine radiation doses to which patients are exposed. In contrast, guidelines and reference levels have been created in Europe to standardize CT radiation doses (13)(14)(15)(16)(17)(18).…”

“…Our data, organized according to anatomic region, offer a practical way to compare CT dose levels across institutions and patients, and this approach has been used in other countries to compare practice (16)(17)(18). U.S. national efforts on creating CT dose-level benchmarks have primarily used survey data in which institutions report typical scanning parameters.…”

“…For example, facilities applying (12). In contrast, there are considerable data and benchmarks from European countries with which to compare our data (13)(14)(15)(16)(17)(18). As reference levels are typically set at the 75% level, we use the data presented in Table 3 to compare with these European publications.…”

“…The median DLPs for single-phase, multiphase, and all examinations, respectively, were as follows: head, 880 mGy · cm (IQR, 640-1120 mGy · cm), 1550 mGy · cm (IQR, 1150-2130 mGy · cm), and 960 mGy · cm (IQR, 690-1300 mGy · cm); chest, 420 mGy · cm (IQR, 260-610 mGy · cm), 880 mGy · cm (IQR, 570-1430 mGy · cm), and 550 mGy · cm (IQR 320-830 mGy · cm); and abdomen, 580 mGy · cm (IQR, 360-860 mGy · cm), 1220 mGy · cm (IQR, 850-1790 mGy · cm), and 960 mGy · cm (IQR, 600-1460 mGy · cm). Median effective doses for single-phase, multiphase, and all examinations, respectively, were as follows: head, 2 mSv (IQR, 1-3 mSv), 4 mSv (IQR, 3-8 mSv), and 2 mSv (IQR, 2-3 mSv); chest, 9 mSv (IQR, 5-13 mSv), 18 mSv (IQR, 12-29 mSv), and 11 mSv (IQR, 6-18 mSv); and abdomen, 10 mSv (IQR, 6-16 mSv), 22 mSv (IQR, 15-32 mSv), and 17 mSv (IQR,(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26). In general, values for children were approximately 50% those for adults in the head and 25% those for adults in the chest and abdomen.…”