Magnetic resonance cholangiopancreatography (MRCP) is widely accepted for visualization of the biliary system. However, the sensitivity and specificity of MRCP for the diagnosis of biliary atresia (BA) are still not fully elucidated. This study aimed to investigate the diagnostic value of three-dimensional MRCP (3D-MRCP) for BA in a large cohort of cholestatic infants and neonates. One hundred ninety patients with infant jaundice underwent 3D-MRCP and one or more of the following: (1) intraoperative cholangiography, (2) laparoscopic exploration and pathological examination, or/and (3) clinical therapy. Statistical analyses were performed to determine the diagnostic accuracy of 3D-MRCP for BA. Our study demonstrated that 158 of 190 patients were interpreted as having BA by 3D-MRCP; of those, 103 patients were confirmed as having BA, whereas 55 patients did not have BA. Of the 32 patients interpreted as non-BA cases by 3D-MRCP, one patient was misdiagnosed. The diagnostic accuracy for 3D-MRCP was 70.53% (134 of 190), the sensitivity was 99.04% (103 of 104), the specificity was 36.05% (31 of 86), the negative predictive value was 96.88% (31 of 32), the positive predictive value was 65.19% (103 of 158), the positive likelihood ratio was 2.7473, the negative likelihood ratio was 0.0267, and the Youden index was 0.3509. The sensitivity of 3D-MRCP in diagnosing BA was excellent, but the specificity was not as high as described in previous reports. 3D-MRCP can be an effective screening method but should be combined with other modalities to identify BA and distinguish it from other causes of infant jaundice.

Background: Various methods have been employed to reduce radiation dose and improve image quality in head computed tomography (CT); however, the impact of different head tilt angles on these factors remains underexplored. Objective: To investigate the effects of different head tilt angles on radiation dose and image quality in head CT. Materials and methods: A pediatric anthropomorphic head phantom was scanned using dual‐source CT at 18 different tilt angles, repeated 10 times at each angle. Image quality was assessed using mean CT (CT _mean ) attenuation values and image noise at six regions of interest (ROIs), while radiation dose was evaluated using volume CT dose index (CTDI _vol ), size‐specific dose estimate (SSDE), and dose‐length product (DLP). The scan lengths of the eyes and head were also recorded. Results: CTDI _vol and SSDE did not exhibit clear variation patterns with changes in head tilt angles, while DLP was in the lower region between −10° and 5°. Head scan lengths were relatively shorter between −10° and 5°, and eye scan lengths were relatively shorter between −10° and 0°. Except for the image noise of the right middle cranial fossa, no significant differences were found in CT _mean values and image noise for the other ROIs between −10° and 0°. Conclusion: The findings indicated that adjusting the head tilt angle within the range of −10° to 0° reduced both the head and eye scan lengths as well as the radiation dose, while preserving relatively stable image quality.

Objective: To investigate the impact of the use of different imaging units and projections on radiation dose and image quality during chest digital radiography (DR) in 3- and 4-year-old children. Methods: Two hundred forty 3- and 4-year-old participants requiring chest DR were included; they were divided into three groups: supine anterior-posterior projection (APP), standing APP and standing posterior-anterior projection (PAP). Each group included 40 participants who were evaluated using the same imaging unit. The dose area product (DAP) and the entrance surface dose (ESD) were recorded after each exposure. The visual grading analysis score (VGAS) was used to evaluate image quality, and the longitudinal distance (LD) from the apex of the right lung to the apex of the right diaphragm was used to evaluate the inspiration extent. Results: DAP and ESD were significantly lower in the standing PAP and APP groups than in the supine APP group (P<0.05), but LD was significantly higher in the standing PAP and APP groups than in the supine APP group (P<0.05). Additionally, the pulmonary field area was significantly higher for the standing PAP group than for the standing and supine APP groups (P<0.05). The correlations between ESD, DAP, and VGAS were positive (P<0.001), showing that larger ESD and DAP correspond to higher VGAS. The correlations between ESD, DAP, and body mass index (BMI) were also positive (P0.05). Conclusion: The radiation dose to superficial organs may be lower with standing PAP than with standing APP during chest DR. Standing PAP should be selected for chest DR in 3- and 4-year-old children, as it may decrease the required radiation dose.

Background: Until now few studies have specially validated whether the sex, body mass index, or imaging projections of pediatric patients undergoing chest digital radiography (DR) affect the radiation dose and image quality. Introduction: To investigate the impact of different photography positions on radiation dose for and image quality of chest DR for 3-4-year-old children. Method: One-hundred twenty 3-4-year-old patients who required chest DR were included. The patients were divided into 3 groups, with 40 patients in each group: supine anterior-posterior projection (APP), standing APP and posterior-anterior projection (PAP). The dose area product (DAP) and entrance surface dose (ESD) values for every patient were recorded after each exposure. The visual grading analysis score (VGAS) was used to evaluate image quality. Result: The DAP and ESD values for the standing PAP and APP groups were significantly lower than those for the supine APP group (0.19 ± 0.04 dGy cm² and 0.05 ± 0.01 mGy vs 0.25 ± 0.05 dGy cm² and 0.08 ± 0.01 mGy, P<0.05, respectively). Additionally, the VGAS for the standing APP group was significantly lower than those for the standing PAP and supine APP groups (28.58 ± 0.96 vs 29.08 ± 0.94 and 29.03 ± 0.80, P<0.05, respectively), whereas the pulmonary field area for the standing PAP group was significantly higher than those for the standing and supine APP groups (118.95 ± 16.81 cm² vs 105.65 ± 14.76 cm² and 105.24 ± 16.32 cm², P0.05, respectively). Conclusion: The standing PAP should be the first projection choice for chest DR for 3-4-year-old children; compared with the supine and standing APP, the standing PAP may improve image quality and decrease the required radiation dose.

Purpose: To investigate the effects of different arm positions on image quality and radiation dose in toddler chest computed tomography (CT). Methods: A phantom experiment and a retrospective clinical study were conducted. In the phantom study, an anthropomorphic phantom was scanned 10 times in three arm positions: arms fully elevated (Group A), arms incompletely elevated with humeri superimposed over shoulders (Group B), and arms alongside the body (Group C). In the clinical study, 120 patients aged 12–36 months were categorized into corresponding groups (Groups 1–3; n = 40 each). Objective image quality was assessed by CT attenuation and noise within predefined regions of interest (ROIs). Subjective quality was scored by two radiologists using a 5-point Likert scale. Radiation dose [volume computed tomography dose index and dose-length product (DLP)] was recorded. Results: Arm position significantly affected CT values and noise in the phantom study, though noise differences were modest. In patients, only one ROI showed a significant noise difference [4.30 HU, 95% confidence interval (95% CI): 0.91–7.69]. Subjective scores were highest for Group 1, lowest for Group 2, and intermediate for Group 3; all images remained diagnostically adequate. Group 2 exhibited the highest radiation dose. Although the DLP difference between Groups 1 and 3 did not reach statistical significance after correction for multiple comparisons (adjusted p = 0.063), the point estimate suggested a numerical trend toward lower DLP in Group 1 (Hodges–Lehmann median difference: 1.80 mGy·cm; unadjusted 95% CI: 0.53–3.63). Conclusion: For toddler chest CT, arms fully elevated is the optimal position. Arms alongside the body is an acceptable alternative when elevation is unfeasible. Humeral superimposition over the shoulders should be avoided whenever possible, as it increases radiation dose and degrades image quality.