76088 research outputs found
Sort by
Radiation dose reduction using deep learning-based image reconstruction for a low-dose chest computed tomography protocol: a phantom study
Get PDFBackground: The aim of this study was to compare the dose reduction potential and image quality of deep learning-based image reconstruction (DLIR) with those of filtered back-projection (FBP) and iterative reconstruction (IR) and to determine the clinically usable dose of DLIR for low-dose chest computed tomography (LDCT) scans. Methods: Multi-slice computed tomography (CT) scans of a chest phantom were performed with various tube voltages and tube currents, and the images were reconstructed using seven methods to control the amount of noise reduction: FBP, three stages of IR, and three stages of DLIR. For subjective image analysis, four radiologists compared 48 image data sets with reference images and rated on a 5-point scale. For quantitative image analysis, the signal to noise ratio (SNR), contrast to noise ratio (CNR), nodule volume, and nodule diameter were measured. Results: In the subjective analysis, DLIR-Low (0.46 mGy), DLIR-Medium (0.31 mGy), and DLIR-High (0.18 mGy) images showed similar quality to the FBP (2.47 mGy) image. Under the same dose conditions, the SNR and CNR were higher with DLIR-High than with FBP and all the IR methods (all P<0.05). The nodule volume and size with DLIR-High were significantly closer to the real volume than with FBP and all the IR methods (all P<0.001). Conclusions: DLIR can improve the image quality of LDCT compared to FBP and IR. In addition, the appropriate effective dose for LDCT would be 0.24 mGy with DLIR-High. © Quantitative Imaging in Medicine and Surgery. All rights reserved.ope
Expanding SPG7 dominant optic atrophy phenotype: Infantile nystagmus and optic atrophy without spastic paraplegia
No full textSpastic paraplegia is a neurodegenerative disorder characterized by progressive leg weakness and spasticity due to degeneration of corticospinal axons. SPG7 encodes paraplegin, and pathogenic variants in the gene cause hereditary spastic paraplegia as an autosomal recessive trait. Various ophthalmological findings including optic atrophy, ophthalmoplegia, or nystagmus have been reported in patients with spastic paraplegia type 7. We report a 15-year-old male patient with a novel heterozygous variant, c.1224T>G:p.(Asp408Glu) in SPG7 (NM_003119.3) causing early onset isolated optic atrophy and infantile nystagmus prior to the onset of neurological symptoms. Therefore, SPG7 should be considered a cause of infantile nystagmus with optic atrophy.restrictio
Feasibility of the virtual reality-based assessments in patients with panic disorder
Get PDFIntroduction: Recurrences and diagnostic instability of panic disorder (PD) are common and have a negative effect on its long-term course. Developing a novel assessment tool for anxiety that can be used in a multimodal approach may improve these problems in panic disorder patients. This study assessed the feasibility of virtual reality-based assessment in panic disorder (VRA-PD).
Methods: Twenty-five patients with PD (ANX group) and 28 healthy adults (CON group) participated in the study. VRA-PD consisted of four modules based on the key components of cognitive behavior therapy for an anxiety disorder: “Baseline evaluation module” (M0), “Daily environment exposure module” (M1), “Relaxation module” (M2), and “Interoceptive exposure module” (M3). Multiple evaluations, including self-rating anxiety scores (AS) and physiological responses [heart rate variability (HRV) index], were performed in three steps at M1, M2, and M3, and once at M0. Comparisons between patients with PD and healthy controls, factor analysis of variables in VRA-PD, changes in responses within modules, and correlation analysis between variables in VRA-PD and anxiety symptoms assessed by psychological scales were performed.
Results : All participants completed the VRA-PD without discontinuation. The ANX group reported significantly higher AS for all steps and a smaller HRV index in M1 (steps 1 and 2) and M2 (step 1). Repeated-measures analysis of covariance (ANCOVA) revealed significant interaction effects for AS in M1 (F = 4.09, p = 0.02) and M2 (F = 4.20, p = 0.02), and HRV index in M2 (F = 16.22, p < 0.001) and M3 (F = 21.22, p = 0.02). The HRV index only indicated a good model fit for the three-factor model, reflecting the construct of the VRA-PD. Both AS and HRV indexes were significantly correlated with anxiety and depression symptoms.
Discussion : The current study provides preliminary evidence that the VRA-PD could be a valid anxiety behavior assessment tool.ope
MECP2 duplication syndrome initially misdiagnosed as cerebral palsy: a case report
Get PDFMutations in the X-linked methyl-CpG-binding protein 2 (MECP2) gene were first described as a
cause of Rett syndrome. MECP2 duplication can cause intellectual disability, developmental delay,
severe feeding difficulties, and recurrent infections. Here, we report a Korean family with MECP2
duplication syndrome, which was previously misdiagnosed as cerebral palsy. A man in his early
30 s visited our clinic with intellectual disability, speech impairment, epilepsy, and progressive
spasticity. He had been previously misdiagnosed with cerebral palsy, and had received orthopedic
surgeries such as musculotendinous lengthening and derotational osteotomy. After the surgeries,
he received comprehensive rehabilitation. Upon carefully checking his family history, we noted
that his younger brother had similar symptoms. Next-generation sequencing revealed whole
exon duplication in MECP2 in both the patient and his brother; their mother also had this genetic
mutation but was asymptomatic. Early diagnosis is essential for improving the success of MECP2
duplication syndrome treatment. Individuals with MECP2 duplication syndrome should be
referred to specialists to manage multidisciplinary symptoms and to regularly check for complications
that are common in this syndrome.ope
Comparison of growth response and adverse reaction according to growth hormone dosing strategy for children with short stature: LG Growth Study
No full textObjective: Growth hormone (GH) dosage in children is conventionally determined either by body weight (BW) or body surface area (BSA). However, there is no consensus on the calculation method for proper GH treatment dose. We aimed to compare growth response and adverse reactions between BW- and BSA-based GH treatment doses for children with short statures.
Design: Data from 2284 GH-treated children were analyzed. Distributions of BW- and BSA-based GH treatment doses and their association with growth response parameters, including changes in height, height standard deviation score (SDS), body mass index (BMI), and safety parameters, such as changes in insulin-like growth factor (IGF)-I SDS and adverse events, were investigated.
Results: The mean BW-based doses were close to the recommended dose's upper limit in participants with GH deficiency and idiopathic short stature, while they were below the recommended dose in patients with Turner syndrome (TS). As age and BW increased, BW-based dose decreased, whereas BSA-based dose increased. Gain in height SDS was positively associated with BW-based dose in the TS group and negatively associated with BW in all groups. Despite having a lower BW-based dose, the overweight/obese groups had a higher BSA-based dose and higher frequencies of children with high IGF-I and adverse events than those of the normal-BMI group.
Conclusions: In children of older age or with high BW, BW-based doses can be overdosed in terms of BSA. and BWbased dose positively correlated with height gain only in the TS group. BSA-based doses represent an alternative dosing strategy in children who are overweight/obese.restrictio
Multi-modulation of immune-inflammatory response using bioactive molecule-integrated PLGA composite for spinal fusion
Get PDFDespite current developments in bone substitute technology for spinal fusion, there is a lack of adequate materials for bone regeneration in clinical applications. Recombinant human bone morphogenetic protein-2 (rhBMP-2) is commercially available, but a severe inflammatory response is a known side effect. Bone graft substitutes that enhance osteogenesis without adverse effects are needed. We developed a bioactive molecule-laden PLGA composite with multi-modulation for bone fusion. This bioresorbable composite scaffold was considered for bone tissue engineering. Among the main components, magnesium hydroxide (MH) aids in reduction of acute inflammation affecting disruption of new bone formation. Decellularized bone extracellular matrix (bECM) and demineralized bone matrix (DBM) composites were used for osteoconductive and osteoinductive activities. A bioactive molecule, polydeoxyribonucleotide (PDRN, PN), derived from trout was used for angiogenesis during bone regeneration. A nano-emulsion method that included Span 80 was used to fabricate bioactive PLGA-MH-bECM/DBM-PDRN (PME2/PN) composite to obtain a highly effective and safe scaffold. The synergistic effect provided by PME2/PN improved not only osteogenic and angiogenic gene expression for bone fusion but also improved immunosuppression and polarization of macrophages that were important for bone tissue repair, using a rat model of posterolateral spinal fusion (PLF). It thus had sufficient biocompatibility and bioactivity for spinal fusion. © 2023ope
Artificial intelligence (AI)-based decision support improves reproducibility of tumor response assessment in neuro-oncology: An international multi-reader study
No full textBackground. To assess whether artificial intelligence (AI)-based decision support allows more reproducible and standardized assessment of treatment response on MRI in neuro-oncology as compared to manual 2-dimensional measurements of tumor burden using the Response Assessment in Neuro-Oncology (RANO) criteria.,Methods. A series of 30 patients (15 lower-grade gliomas, 15 glioblastoma) with availability of consecutive MRI scans was selected. The time to progression (TTP) on MRI was separately evaluated for each patient by 15 investigators over two rounds. In the first round the TTP was evaluated based on the RANO criteria, whereas in the second round the TTP was evaluated by incorporating additional information from AI-enhanced MRI sequences depicting the longitudinal changes in tumor volumes. The agreement of the TTP measurements between investigators was evaluated using concordance correlation coefficients (CCC) with confidence intervals (CI) and P-values obtained using bootstrap resampling.,Results. The CCC of TTP-measurements between investigators was 0.77 (95% CI = 0.69,0.88) with RANO alone and increased to 0.91 (95% CI = 0.82,0.95) with AI-based decision support (P = .005). This effect was significantly greater (P = .008) for patients with lower-grade gliomas (CCC = 0.70 [95% CI = 0.56,0.85] without vs. 0.90 [95% CI = 0.76,0.95] with AI-based decision support) as compared to glioblastoma (CCC = 0.83 [95% CI = 0.75,0.92] without vs. 0.86 [95% CI = 0.78,0.93] with AI-based decision support). Investigators with less years of experience judged the AI-based decision as more helpful (P = .02).,Conclusions. AI-based decision support has the potential to yield more reproducible and standardized assessment of treatment response in neuro-oncology as compared to manual 2-dimensional measurements of tumor burden, particularly in patients with lower-grade gliomas. A fully-functional version of this AI-based processing pipeline is provided as open-source (https://github.com/NeuroAI-HD/HD-GLIO-XNAT).,restrictio
Proposal of nomograms to predict clinical outcomes in patients with ampulla of Vater cancer based on the Korea-Japan collaborative study
No full textBackground In this study, we aimed to develop and validate a nomogram to predict overall survival (OS) and recurrence-free survival (RFS) in patients who underwent curative resection of ampulla of Vater (AOV) cancer. This is the first study for nomograms in AOV cancer patients using retrospective data based on an international multicenter study. Methods A total of 2007 patients with AOV adenocarcinoma who received operative therapy between 2002 January and 2015 December in Korea and Japan were retrospectively assessed to develop a prediction model. Nomograms for 5-year OS and 3-year RFS were constructed by dividing the patients who received and who did not receive adjuvant therapy after surgery, respectively. Significant risk factors were identified by univariate and multivariate Cox analyses. Performance assessment of the four prediction models was conducted by the Harrell's concordance index (C-index) and calibration curves using bootstrapping. Results A total of 2007 and 1873 patients were collected for nomogram construction to predict 5-year OS and 3-year RFS. We developed four types of nomograms, including models for 5-year OS and 3-year RFS in patients who did not receive postoperative adjuvant therapy, and 5-year OS and 3-year RFS in patients who received postoperative adjuvant therapy. The C-indices of these nomograms were 0.795 (95% confidence interval [CI]: 0.766-0.823), 0.712 (95% CI: 0.674-0.750), 0.804 (95% CI: 0.7778-0.829), and 0.703 (95% CI: 0.669-0.737), respectively. Conclusions This predictive model could help clinicians to choose optimal treatment and precisely predict prognosis in AOV cancer patients.restrictio
Combined Effects of Focused Ultrasound and Photodynamic Treatment for Malignant Brain Tumors Using C6 Glioma Rat Model
Get PDFPurpose: Glioblastoma (GBM) is an intractable disease for which various treatments have been attempted, but with little effect. This study aimed to measure the effect of photodynamic therapy (PDT) and sonodynamic therapy (SDT), which are currently be ing used to treat brain tumors, as well as sono-photodynamic therapy (SPDT), which is the combination of these two.
Materials and Methods: Four groups of Sprague-Dawley rats were injected with C6 glioma cells in a cortical region and treated with PDT, SDT, and SPDT. Gd-MRI was monitored weekly and 18F-FDG-PET the day before and 1 week after the treatment. The acoustic power used during sonication was 5.5 W/cm2 using a 0.5-MHz single-element transducer. The 633-nm laser was illumi nated at 100 J/cm2. Oxidative stress and apoptosis markers were evaluated 3 days after treatment using immunohistochemistry (IHC): 4-HNE, 8-OhdG, and Caspase-3.
Results: A decrease in tumor volume was observed in MRI imaging 12 days after the treatment in the PDT group (p<0.05), but the SDT group showed a slight increase compared to the 5-Ala group. The high expression rates of reactive oxygen species-related factors, such as 8-OhdG (p<0.001) and Caspase-3 (p<0.001), were observed in the SPDT group compared to other groups in IHC.
Conclusion: Our findings show that light with sensitizers can inhibit GBM growth, but not ultrasound. Although SPDT did not show the combined effect in MRI, high oxidative stress was observed in IHC. Further studies are needed to investigate the safety parameters to apply ultrasound in GBM.ope