Hiroki Kajita

Background: Positional cranial deformities are common in infancy. Smartphone-based apps are increasingly used to assess infant head shape, but evidence comparing these tools with 3D scanners across age groups in community-based settings remains limited. Objective: This study evaluated age-stratified agreement and screening performance of a mobile app for estimating Cranial Vault Asymmetry Index (CVAI) and Cephalic Index, compared with a 3D scanner, when used by a trained examiner during routine municipal health checkups in Japan. Methods: We conducted a cross-sectional study in Goto City, Japan, between May 2023 and March 2025. Independent, age-specific cohorts of children attending municipal health checkups at 4, 18, and 42 months were included. Paired cranial measurements were obtained by a trained examiner using a VECTRA H2 3D scanner (Canfield Scientific Inc) and the mobile app. Agreement was assessed using mean differences, 95% limits of agreement (LoA), and intraclass correlation coefficients (ICCs), with device-stratified sensitivity analyses. Screening performance was evaluated using sensitivity and specificity based on prespecified clinical thresholds. Receiver operating characteristic (ROC) analyses were secondary exploratory analyses. The primary outcome was app-based CVAI for detecting scanner-defined moderate-or-worse plagiocephaly (CVAI≥7%). Secondary outcomes were app-based Cephalic Index for detecting brachycephaly (Cephalic Index>94%) and dolichocephaly (Cephalic Index<79%). Results: The final analytic samples comprised 262 children at 4 months, 171 at 18 months, and 216 at 42 months. Agreement for continuous CVAI was highest at 4 months (mean difference 0.14, 95% LoA −4.18 to 4.46; ICC 0.76, 95% CI 0.71‐0.81) and lower at 18 months (ICC 0.42, 95% CI 0.29‐0.54) and 42 months (ICC 0.49, 95% CI 0.38‐0.59). For Cephalic Index, the app consistently overestimated values relative to the scanner, with mean differences of 3.83 SD 3.42, 3.24 SD 3.07, and 2.61 SD 3.33 points at 4, 18, and 42 months, respectively. For detecting scanner-defined moderate-or-worse plagiocephaly, app sensitivity and specificity were 84.8% and 88.0% at 4 months, 50.0% and 88.4% at 18 months, and 53.3% and 89.6% at 42 months, respectively. Device-stratified analyses showed some variation in measurement agreement and screening performance across devices. Conclusions: Under municipal health checkup conditions with a trained examiner, app-based CVAI showed the strongest performance at 4 months and may be useful for early screening. However, performance was weaker at 18 and 42 months. App-based Cephalic Index was systematically higher than scanner-based Cephalic Index, potentially increasing false-positive classifications for brachycephaly when identical thresholds are applied. Performance varied somewhat between devices, although device effects could not be separated from study period and accumulated examiner experience. Positive findings, particularly at later ages or for Cephalic Index–based measures, should be interpreted in the context of the child’s age and broader clinical findings, with further evaluation or referral considered only when clinically indicated.

Background and Objectives: Lymphaticovenular anastomosis (LVA) is a surgical technique used to alleviate lymphedema by bypassing the lymphatic and venous vessels and facilitating lymphatic fluid drainage. Accurate evaluation of anastomotic patency is crucial for assessing LVA outcomes. Traditional near‐infrared fluorescence lymphography has limitations, including fluorescence diffusion in subcutaneous fat and difficulty evaluating areas beneath the dermal backflow. Photoacoustic imaging (PAI) is a potential alternative for high‐resolution visualization of lymphatic and blood vessels. We aimed to evaluate the utility of PAI for assessing LVA patency.Methods: Using the LUB0 PAI system, we examined patients who underwent LVA. Imaging was conducted using subcutaneously injected indocyanine green (ICG) to visualize lymphatic vessels.Results: Results showed clear patency in some cases, inability to evaluate it in others, and confirmed occlusion in certain instances.Conclusions: While PAI provides valuable insights, challenges remain, including the potential for ambiguous results from the intermittent nature of lymphatic flow and difficulty visualizing low‐ICG‐concentration lymphatic vessels. Nonetheless, PAI offers a promising method for detailed 3D evaluation of anastomoses. It may improve surgical outcomes and contribute to future evidence in the field. Further advancements, including real‐time video assessment, may enhance the accuracy and reliability of LVA patency evaluation.

Background: Identification of the proper lymphatics is important for successful lymphaticovenular anastomosis (LVA) for lymphedema; however, visualization of lymphatic vessels is challenging. Photoacoustic lymphangiography (PAL) can help visualize lymphatics more clearly than other modalities. Therefore, we investigated the usefulness of PAL and determined whether the clear and three‐dimensional image of PAL affects LVA outcomes.Methods: We recruited 22 female patients with lower extremity lymphedema. The operative time, number of incisions, number of anastomoses, lymphatic vessel detection rate (number of functional lymphatics identified during the operation/number of incisions), and limb volume changes preoperatively and 3 months postoperatively were compared retrospectively. The patients were divided according to whether PAL was performed or not, and results were compared between those undergoing PAL (PAL group; n = 10) and those who did not (near‐infrared fluorescence [NIRF] group, n = 12).Results: The mean age of the patients was 55.9 ± 15.1 years in the PAL group and 50.7 ± 14.9 years in the NIRF group. One patient in the PAL group and three in the NIRF group had primary lymphedema. Eighteen patients (PAL group, nine; and NIRF group, nine) had secondary lymphedema. Based on preoperative evaluation using the International Society of Lymphology (ISL) classification, eight patients were determined to be in stage 2 and two patients in late stage 2 in the PAL group. In contrast, in the NIRF group, one patient was determined to be in stage 0, three patients each in stage 1 and stage 2, and five patients in late stage 2.Lymphatic vessel detection rates were 93% (42 LVAs and 45 incisions) and 83% (50 LVAs and 60 incisions) in the groups with and without PAL, respectively (p = 0.42). Limb volume change was evaluated in five limbs of four patients and in seven limbs of five patients in the PAL and NIRF groups as 336.6 ± 203.6 mL (5.90% ± 3.27%) and 52.9 ± 260.7 mL (0.71% ± 4.27%), respectively. The PAL group showed a significant volume reduction. (p = .038).Conclusions: Detection of functional lymphatic vessels on PAL is useful for treating LVA.

Background With the advent of cranial orthoses as therapeutic medical devices for the treatment of severe positional head deformities in Japan, an increasing number of patients are being treated with them. However, assessing the effectiveness of a treatment is often difficult due to the use of different metrics. This study aimed to evaluate the effectiveness of cranial orthoses for deformational plagiocephaly using two- (2D) and three-dimensional (3D) evaluation metrics. Methods We conducted a retrospective study of infant patients with deformational plagiocephaly who underwent cranial orthosis treatment. We evaluated the severity of deformational plagiocephaly using cranial asymmetry (CA) and the cranial vault asymmetry index (CVAI) as 2D metrics, and anterior and posterior symmetry ratios as 3D metrics. The patients were divided into 24 subgroups based on the initial severity of each outcome and their age at the start of treatment. We analyzed the changes in outcomes and correlations within improvements across the age and severity categories. Results Overall, 1,038 infants were included in this study. The mean CA, CVAI, and anterior and posterior symmetry ratios improved significantly after cranial orthosis treatment. The improvement in each score was greater in patients with more severe initial deformities and in those who underwent treatment at a younger age. Conclusion Cranial orthosis treatment was effective in correcting deformational plagiocephaly in infants, as demonstrated by improvements in both 2D and 3D metrics. Patients with more severe initial deformities and those who underwent treatment at a younger age showed greater improvement.

Mounting multi-view cameras within a surgical light is a practical choice since some cameras are expected to observe surgery with few occlusions. Such multi-view videos must be reassembled for easy reference. A typical way is to reconstruct the surgery in 3D. However, the geometrical relationship among cameras is changed because each camera independently moves every time the lighting is reconfigured (i.e., every time surgeons touch the surgical light). Moreover, feature matching between surgical images is potentially challenging because of missing rich features. To address the challenge, we propose a feature-matching strategy that enables robust calibration of the multi-view camera system by collecting a set of a small number of matches over time while the cameras stay stationary. Our approach would enable conversion from multi-view videos to a 3D video. However, surgical videos are long and, thus, the cost of the conversion rapidly grows. Therefore, we implement a video player where only selected frames are converted to minimize time and data until playbacks. We demonstrate that sufficient calibration quality with real surgical videos can lead to a promising 3D mesh and a recently emerged 3D multi-layer representation. We reviewed comments from surgeons to discuss the differences between those 3D representations on an autostereoscopic display with respect to medical usage.