Improving the visibility of lung nodules, which are often hidden by bone shadows and difficult to identify, mains a challenge in chest radiography. This study aims to develop an algorithm for generating novel bone suppressed images using photon-counting techniques. The core idea of our algorithm is to fit photon interaction cross-sections to X-ray attenuation data measured with photon-counting detectors. Based on further calculations using the derived fitting coefficients, both density (rho) and amount-of-substance concentration (mol) were determined. The product of these values produced a rho & times; mol image exhibiting a clear bone-suppression effect. We conducted a virtual chest imaging simulation using 10 patient datasets acquired via clinical photon-counting computed tomography (PC-CT). The CT images were converted into rho & times; mol images following the proposed processing procedure, and two-dimensional chest images were generated through projection. Quantitative evaluations confirmed that the proposed images achieved sufficient bone suppression. Furthermore, commercial software provided by a vendor was used to generate bone-suppressed images from conventional images projected from CT data. A comparable bone-suppression effect on the ribs was observed between the vendor-generated images and our proposed images, while lesion visibility (e.g., lung nodules) was preserved. Additionally, bone-suppression effects in our images were observed in the vertebrae and clavicles located outside the lung fields. Our research demonstrates the value of constructing general X-ray imaging systems using photon detectors.
Abstract Background The initiation of hemodialysis (HD) is a physiologically and functionally unstable period, often marked by abrupt fluid shifts, metabolic disturbances, and clinical decompensation. Frailty at HD initiation is associated with adverse outcomes. However, the link between unplanned dialysis initiation and frailty remains unclear. Because unplanned initiation often reflects insufficient predialysis care and acute systemic decline, it may be associated with frailty status at initiation. Methods This single-center cross-sectional study enrolled 93 patients with end-stage renal disease who initiated HD between September 2022 and September 2024. Frailty was assessed using the Japanese version of the Cardiovascular Health Study (J-CHS) criteria. The primary exposure was dialysis initiation type (planned versus unplanned). Prevalence ratios (PR) for frailty were estimated using modified Poisson regression. Sensitivity analyses included analyses excluding the weight-loss component, reanalysis using the Clinical Frailty Scale, and additional adjustment for delayed rehabilitation initiation. Results Frailty prevalence at dialysis initiation was 51.6%. It was significantly higher in the unplanned group than in the planned group (74.2% versus 40.3%, p = 0.002). Unplanned initiation was significantly associated with frailty (PR 1.65; 95% confidence interval [CI] 1.04–2.62). Conclusions Unplanned dialysis initiation was significantly associated with a higher prevalence of frailty at dialysis initiation. These findings suggest that patients undergoing unplanned initiation may represent a subgroup with a particularly high frailty burden at the time of dialysis transition, supporting the clinical importance of frailty assessment at dialysis initiation.
To determine the extent of possible dose reduction with photon-counting detector computed tomography (PCD-CT) while maintaining image quality equivalent to that of energy-integrating detector CT (EID-CT) images at standard dose in the temporal bone. PCD-CT and EID-CT imaging quality were compared by visual evaluation of clinical temporal bone images and visual scores with Welch’s t-test at standard dose. A head phantom was used to evaluate imaging quality under dose reduction. The detectability index (d’) of the PCD-CT images at various dose levels and the EID-CT images at standard dose was evaluated. Dose reduction limit with PCD-CT used in the subsequent clinical evaluation was determined as the lowest dose with image quality equal to or better than EID-CT. The clinical equivalence of PCD-CT image quality at the determined reduced dose to that with EID-CT at standard dose was evaluated using visual scores. Equivalence was determined if the 95
Spontaneous closure of a Fontan fenestration may precipitate early hemodynamic deterioration in vulnerable patients. In such situations, fenestration re-creation may be considered as a rescue strategy when medical therapy is insufficient. However, the long-term hemodynamic consequences of this intervention remain poorly defined. We retrospectively reviewed 62 patients who underwent the Fontan procedure between January 2011 and December 2020 and subsequently experienced spontaneous fenestration closure. Patients were divided into two groups according to management strategy: those who underwent fenestration re-creation (Group 1, n = 19) and those managed without re-creation (Group 2, n = 43). Longitudinal hemodynamic data were analyzed using linear mixed models over a median follow-up of 10.2 years. Fenestration closed spontaneously at a median of 12 days (IQR 2.5–26.5) and initial re-creation was performed at the median of 42 days (IQR 11–213) postoperatively. Early and mide-term hemodynamic trends were broadly similar between groups, however, clear divergence emerged in the late follow-up. fenestration re-created patients demonstrated persistently higher central venous pressure and pulmonary vascular resistance, lower systemic vascular resistance, progressive increases in cardiac index, and declining oxygen saturation. Survival in this group remained above 80
The purpose of the study is to review reported cases of dupilumab-associated drug-induced sarcoidosis-like reaction (DISR) and consider possible immunologic mechanisms. This short review aims to raise awareness of dupilumab-associated DISR and discuss safety considerations in pediatric patients.Conclusion: Dupilumab is a human monoclonal antibody that reduces inflammation driven by T helper 2 (Th2) cells and is used to treat type 2 inflammatory disorders, including atopic dermatitis. The most common adverse reactions during the first year of treatment are local reactions at the injection site, conjunctivitis, and headache. Although DISR is rare, it has been documented in dupilumab-treated patients. We hypothesized that dupilumab shifts the Th1/Th2 equilibrium toward Th1 and granulomatous inflammation, which may present as DISR. We identified and reviewed 10 recently reported DISR cases and observed that reported features of DISR-including uveitis, optic neuritis and meningoencephalitis, bilateral hilar lymphadenopathy, and histopathologically noncaseating granulomas-can mimic systemic sarcoidosis. Discontinuation of dupilumab resulted in favorable outcomes in most reported DISR cases; however, symptoms worsened in some cases and sequelae became a concern. Case reports of DISR have so far been limited to adults or adolescents, but awareness of potential adverse effects of dupilumab remains important in pediatric patients.
