The effective dose (HE) and organ or tissue equivalent dose (HT) for use in brain computed tomography (CT) examinations with various body weights were evaluated. Thermoluminescent dosimeters (TLD-100H) were inserted into Rando and five anthropomorphic phantoms. These phantoms were made of polymethylmethacrylate (PMMA), according to the specifications of ICRU 48, with masses from 10 to 90 kg. Brain CT examinations were conducted, scanning the maxillae from the external auditory meatus to the parietal bone using a 128-slice multi-detector CT (MDCT) scanner. To reduce errors, three independent trials were conducted. Calculated HE,TLD, based on the weighting factor recommended by ICRP 103, was 1.72 ± 0.28 mSv, which slightly exceeds the HE,DLP of 1.70 mSv, that was calculated from the dose–length product (DLP) of the Rando phantom. This experiment yielded HE,TLD values of ICRP 103 from the highest 1.85 ± 0.28 (90 kg) to the lowest 1.47 ± 0.22 (10 kg) mSv. HE,TLD (mSv) = 5.45×10−3 W(kg) + 1.361, with an R2 of 0.87667. Using the DLP protocol, HE,DLP was estimated from CTDIvol that was recorded directly from the console display of the CT unit and multiplied by the conversion coefficient (k) recommended by the ICRP 103. Finally, the experimental results obtained herein are compared with those in the literature. Physicians should choose and adjust protocols to prevent the exposure of patients to unnecessary radiation, satisfying the as low as reasonably achievable (ALARA) principle. These findings will be valuable to patients, physicians, radiologists and the public.

H were calculated using ICRP 60 and 103 at 2.67 ± 0.18 and 1.89 ± 0.23 mSv based on an axial scan, and 4.70 ± 0.38 and 4.39 ± 0.37 mSv based on a helical scan, respectively. In the DLP method, H was estimated from CTDI that was recorded directly from the console display of the CT unit and then calculated using AAPM 96. Finally, experimental results are compared with those in literature. Radiologists should choose and adjust protocols to prevent unnecessary radiation to patients and satisfying the as low as reasonably achievable (ALARA) principle. These findings will be valuable to patients, physicians, radiologists, and the public.

This study optimized spatial resolution of mammography imaging quality using a CIRS-016A commercial line gauge and the Taguchi methodology. The line gauge with a precise line pair from 5[Formula: see text]lp/mm to 20[Formula: see text]lp/mm was placed on top of triangular PMMA plates to simulate the female breast undergoing mammography. Five factors: target/filter, kVp, mAs, PMMA plate thickness, and compression force, were organized into 18 groups according to the Taguchi L[Formula: see text] orthogonal array. Tactically, the 18 various combinations of factors could provide similar confidence levels, as those following the full factorial combination in reality. Seven experienced radiology experts judged the 18 imaging qualities based on contrast, sharpness, and spatial resolution. Then the signal-to-noise ratio was calculated according to the “the larger, the better” ranking order. The optimal preset of mammography was verified from the unique fish bone plot and the follow-up analysis of variance (ANOVA) test. The optimal combination of factors was as follows: Rh/Ag as target/filter, 32[Formula: see text]kVp, 36[Formula: see text]mAs, a 45[Formula: see text]mm thick PMMA plate, and a 13[Formula: see text]daN compression force in routine diagnosis. The concurrent resolution of 6[Formula: see text]lp/mm or about a 0.09[Formula: see text]mm minimum detectable difference (MDD) was superior to 5[Formula: see text]lp/mm of the conventional preset or combinations of factors of either highest Avg or lowest std. Compared to other studies with various facilities, this was the finest resolution among the routine X-ray, cardiac X-ray or computed tomography (CT), and computed tomography angiography (CTA).

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