Ibaraki Prefectural University of Health Sciences

We examined whether the multilineage potential of mouse fetal brain cells is induced by the three-dimensional (3D) structural reconstruction. Dissociated single cells from the cerebral hemispheres of mouse fetuses at embryonic day 14.5-15 (E14.5-15) rapidly aggregated into cell clusters, forming spherical cell aggregates (SCAs). Immunofluorescence staining revealed that SCAs were positive for Map2 but negative for Nestin, GFAP, and markers of undifferentiated cells such as Oct4, SSEA-1, ALDH2, and CD133. During culture of SCAs in embryonic stem cell medium, SCAs subsequently developed into embryoid bodies (EBs), which began to exhibit positive immunofluorescence staining for Oct4. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting analyses further confirmed the expression of Oct4 and Nanog at the gene and protein levels. Differentiated cells of EBs induced by culture in various types of media showed positive immunofluorescence staining for lineage-specific markers, including AFP, α-SMA, GFAP, Map2 and C-peptide and expressed the corresponding genes and proteins. These results suggest that mouse fetal brain cells can regain multilineage potential through the reconstruction of 3D structures without genetic modification. Our findings indicate that 3D culture systems may support non-genetic reprogramming strategies in regenerative medicine by activating intrinsic plasticity of cells.

Patient-specific radiation dose management in radiography is essential for optimizing diagnostic quality while minimizing patient exposure. However, current methods often rely on standardized protocols or empirical judgment, which may be inaccurate for patients with non-standard body sizes. Accurate, non-invasive measurement of subject thickness is critical for estimating entrance surface dose (ESD) tailored to each patient. This study aimed to evaluate the feasibility and accuracy of using an RGB-D camera for real-time subject thickness measurement and patient-specific ESD estimation in abdominal radiography.

An abdominal phantom with five thicknesses (20-40 cm) was constructed using an anthropomorphic model and water-equivalent slabs. An RGB-D camera (Intel RealSense D435i) was mounted on a radiography unit to acquire depth measurements at the detector center and four off-center positions (5 cm upward, downward, leftward, and rightward). Measured thicknesses were compared to caliper measurements. ESD was calculated using both RGB-D and caliper-derived values. Levene's test assessed positional effects on measurement variability.

At the detector center, RGB-D-derived thicknesses deviated by no more than ±0.3 cm from actual values. Off-center measurements showed slightly larger errors, up to ±1.2 cm. Significant variance differences were found only at 20 cm thickness in the lateral positions (p < 0.05). ESD estimates from RGB-D-based thickness measurements differed by no more than 0.4 mGy, with percentage differences within ±0.7 %.

RGB-D camera-based thickness measurement is a feasible and accurate method for non-invasive, patient-specific ESD estimation in abdominal radiography.

This approach enables pre-imaging dose estimation, supports personalized dose control, and may improve safety and consistency in radiographic practice.

To investigate the agreement in apparent diffusion coefficient (ADC) values and the image quality of abdominal computed diffusion-weighted imaging (cDWI) generated by two software programs.

This retrospective study included 154 patients (64 males, 90 females; mean age: 70.1 ± 10.7 years) who underwent abdominal diffusion-weighted imaging (DWI) between November 2023 and October 2024. DWI was acquired with a b = 0 and 1000 s/mm² using a 3.0T scanner. cDWIs with b 1500 and 2000 were generated by a scanner console software and a commercially available software program. The ADC and signal-to-noise ratio (SNR) were measured in normal tissues. The contrast-to-noise ratio (CNR) of normal tissues relative to the paraspinal muscle was also measured. Agreement and reliability of ADC value were assessed using Bland-Altman analysis and intraclass correlation coefficients (ICC), respectively. SNR and CNR were compared using paired t-tests.

ADC bias and limits of agreement ranged from - 0.2 to 0.7% and 0.3-2.1%, respectively. ICCs for ADC values ranged within 0.991 and 1.000 (p < 0.05) for all tissues. Significant SNR differences were observed in b1500 (liver, spleen, kidney) and b2000 (liver, bile). Significant CNR differences were noted in b1500 (liver, pancreas, kidney) and b2000 (excluding spleen).

There is strong agreement and high reliability in ADC values between the two software programs. Although significant differences in SNR and CNR were observed, their clinical impact appears minimal. These findings indicate that the ADC values and image quality of cDWI are consistent between the two software programs.