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PURPOSE: We developed new deep learning-based hierarchical brain segmentation (DLHBS) method that can segment T1-weighted MR images (T1WI) into 107 brain subregions and calculate the volume of each subregion. This study aimed to evaluate the repeatability and reproducibility of volume estimation using DLHBS and compare them with those of representative brain segmentation tools such as statistical parametric mapping (SPM) and FreeSurfer (FS). METHODS: Hierarchical segmentation using multiple deep learning models was employed to segment brain subregions within a clinically feasible processing time. The T1WI and brain mask pairs in 486 subjects were used as training data for training of the deep learning segmentation models. Training data were generated using a multi-atlas registration-based method. The high quality of training data was confirmed through visual evaluation and manual correction by neuroradiologists. The brain 3D-T1WI scan-rescan data of the 11 healthy subjects were obtained using three MRI scanners for evaluating the repeatability and reproducibility. The volumes of the eight ROIs-including gray matter, white matter, cerebrospinal fluid, hippocampus, orbital gyrus, cerebellum posterior lobe, putamen, and thalamus-obtained using DLHBS, SPM 12 with default settings, and FS with the "recon-all" pipeline. These volumes were then used for evaluation of repeatability and reproducibility. RESULTS: In the volume measurements, the bilateral thalamus showed higher repeatability with DLHBS compared with SPM. Furthermore, DLHBS demonstrated higher repeatability than FS in across all eight ROIs. Additionally, higher reproducibility was observed with DLHBS in both hemispheres of six ROIs when compared with SPM and in five ROIs compared with FS. The lower repeatability and reproducibility in DLHBS were not observed in any comparisons. CONCLUSION: Our results showed that the best performance in both repeatability and reproducibility was found in DLHBS compared with SPM and FS.
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Reducing the amount of projection data in computed tomography (CT), specifically sparse-view CT, can reduce exposure dose; however, image artifacts can occur. We quantitatively evaluated the effects of conditional generative adversarial networks (CGAN) on image quality restoration for sparse-view CT using simulated sparse projection images and compared them with autoencoder (AE) and U-Net models. The AE, U-Net, and CGAN models were trained using pairs of artifacts and original images; 90% of patient cases were used for training and the remaining for evaluation. Restoration of CT values was evaluated using mean error (ME) and mean absolute error (MAE). The image quality was evaluated using structural image similarity (SSIM) and peak signal-to-noise ratio (PSNR). Image quality improved in all sparse projection data; however, slight deformation in tumor and spine regions was observed, with a dispersed projection of over 5°. Some hallucination regions were observed in the CGAN results. Image resolution decreased, and blurring occurred in AE and U-Net; therefore, large deviations in ME and MAE were observed in lung and air regions, and the SSIM and PSNR results were degraded. The CGAN model achieved accurate CT value restoration and improved SSIM and PSNR compared to AE and U-Net models.
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Artefatos , Tomografia Computadorizada por Raios X , Humanos , Tomografia Computadorizada por Raios X/métodos , Razão Sinal-Ruído , Pulmão/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodosRESUMO
The Objective Structured Clinical Examination (OSCE) is designed to assess medical students' skills and attitude competencies before clinical practice. However, no method of reflective learning using video-based content has been used in OSCE education. This study aimed to confirm whether using smart glasses-based educational content is effective for OSCE reflective learning using multiple views (patient, student, and overall). This educational intervention study included a control group exposed to the traditional learning method and an intervention group exposed to a learning method incorporating smart glasses. Participants were 117 (72 in the control group and 45 in the intervention group) third-year radiological technology students scheduled to take the OSCE and 70 (37 in the control group and 33 in the intervention group) who met the eligibility criteria. Mock OSCEs were administered before and after the educational intervention (traditional and smart glasses-based education) to investigate changes in scores. After the educational intervention, a self-reported comprehension survey and a questionnaire were administered on the effectiveness of the video-based content from different views for student reflective learning. Unexpectedly, the OSCE evaluation score after the preliminary investigation significantly increased for the smart glasses control group (0.36±0.1) compared to the intervention group (0.06±0.1) setting up the radiographic conditions (x-ray center and detector center; p = 0.042). The intervention group's lower score in the mock OSCEs may have been due to the discomfort of wearing the smart glasses to perform the radiography procedure and their unfamiliarity with the smart glasses, which may have affected their concentration. The findings suggest that smart glasses-based education for OSCEs can be improved (e.g., being easy to handle and use and trouble-free).
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Óculos Inteligentes , Estudantes de Medicina , Humanos , Avaliação Educacional/métodos , Aprendizagem , Radiografia , Competência ClínicaRESUMO
PURPOSE: National diagnostic reference levels in Japan 2020 (DRLs 2020) have been published. In the field of angiography, in addition to the fluoroscopic dose rate, incident air kerma at the patient entrance reference point displayed on the equipment (Ka,r: mGy) and air kerma-area product displayed on the equipment (PKA: Gycm2) were set. A questionnaire survey was conducted at each facility in the Tokai region to confirm the status of medical radiation dose control in the region. METHOD: A questionnaire survey was conducted at each facility in the Tokai region. The items were fluoroscopic dose rate in each area (head and neck, cardiac, chest and abdomen, and limbs), DA and DSA dose rates, and dose area product meter (Ka,r, PKA) for the main procedures in each area. RESULT: The median values in this study were lower than those in the DRLs 2020, indicating that appropriate dose control is being implemented in the Tokai region. The trends of fluoroscopic and radiographic dose rates were different in each area, and there was some variation among the facilities. CONCLUSION: We believe that the incorporation of fluoroscopic and radiographic dose rates by area into the DRLs will facilitate more appropriate dose control at each facility in the future.
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Angiografia , Humanos , Doses de Radiação , Fluoroscopia , Inquéritos e Questionários , Valores de ReferênciaRESUMO
In automated analyses of brain morphometry, skull stripping or brain extraction is a critical first step because it provides accurate spatial registration and signal-intensity normalization. Therefore, it is imperative to develop an ideal skull-stripping method in the field of brain image analysis. Previous reports have shown that convolutional neural network (CNN) method is better at skull stripping than non-CNN methods. We aimed to evaluate the accuracy of skull stripping in a single-contrast CNN model using eight-contrast magnetic resonance (MR) images. A total of 12 healthy participants and 12 patients with a clinical diagnosis of unilateral Sturge-Weber syndrome were included in our study. A 3-T MR imaging system and QRAPMASTER were used for data acquisition. We obtained eight-contrast images produced by post-processing T1, T2, and proton density (PD) maps. To evaluate the accuracy of skull stripping in our CNN method, gold-standard intracranial volume (ICVG) masks were used to train the CNN model. The ICVG masks were defined by experts using manual tracing. The accuracy of the intracranial volume obtained from the single-contrast CNN model (ICVE) was evaluated using the Dice similarity coefficient [= 2(ICVE â ICVG)/(ICVE + ICVG)]. Our study showed significantly higher accuracy in the PD-weighted image (WI), phase-sensitive inversion recovery (PSIR), and PD-short tau inversion recovery (STIR) compared to the other three contrast images (T1-WI, T2-fluid-attenuated inversion recovery [FLAIR], and T1-FLAIR). In conclusion, PD-WI, PSIR, and PD-STIR should be used instead of T1-WI for skull stripping in the CNN models.
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Encéfalo , Crânio , Humanos , Crânio/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Redes Neurais de Computação , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodosRESUMO
To propose reference values for air-kerma at the reference point (Ka,r), air-kerma area product (PKA), fluoroscopy time (FT) and number of cine images (CI) for four age groups in Japan, a nationwide questionnaire was posted to 132 pediatric catheterisation of certified facility in Japan, using the conventional post system, to which 43 facilities responded. For diagnostic cardiac angiography, reference values were as follows: Ka,r: 86, 102, 165 and 264 mGy; PKA: 9.3, 9.5, 16 and 34 Gy.cm2; FT: 33, 29, 26 and 30 min and CI: 1904, 1966, 2405 and 1871 images. For therapeutic cardiac angiography, reference values were as follows: Ka,r: 107, 163, 103 and 202 mGy; PKA: 7.5, 18, 7 and 24 Gy.cm2; FT: 56, 52, 42 and 30 min and CI: 3886, 3232, 2212 and 4316 images for less than 1, 1-5, 6-10 and 11-15 y, respectively. To optimal patient exposure from diagnostic and therapeutic cardiac catheterisation, it is therefore necessary to establish reference values for pediatric cardiac catheterisation examinations for four age groups.
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Cateterismo Cardíaco , Radiografia Intervencionista , Humanos , Criança , Doses de Radiação , Japão , Inquéritos e Questionários , FluoroscopiaRESUMO
OBJECTIVE: Subject contrast of pulmonary tissues was investigated for five X-ray beams (70 kV without filter, 90 kV with 0.15 mm Cu filter, 90 kV with 0.2 mm Cu filter, 120 kV without filter, and 120 kV with 0.2 mm Cu filter) in CsI-FPD chest radiography using two types of model phantoms by Monte Carlo simulation. METHODS: A total of 72 million photons were entered to the model lung phantom (width, 300 mm; length, 300 mm; thickness, 200 mm; air space, 120 mm) and model mediastinum phantom (width, 300 mm; length, 300 mm; thickness, 200 mm; air space, 40 mm). Individual primary and secondary photon's process (absorption, scattering, and penetration) in the phantom and CsI-detector was recorded by Monte Carlo simulation. Subject contrast was calculated by entered and absorbed photon's number in the CsI-detector. RESULTS: Subject contrast pulmonary tissues were high to low energy X-ray beam; however, the ones of soft tissue and soft tissue overlaying bone had few differences for beam quality except 70 kV without filter. Moreover, the subject contrast by absorbed photons was higher compared to the one by entered photons in CsI. CONCLUSION: It was shown that the subject contrast study by Monte Carlo calculation can be replaced by the way of physical chest phantom, and that the subject contrast by absorbed photons and by injected photons in CsI was different. Furthermore, be verified that the subject contrast of soft tissue and soft tissue overlaying bone differs hardly.
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Pulmão , Fótons , Método de Monte Carlo , Radiografia , Simulação por Computador , Raios X , Pulmão/diagnóstico por imagem , Imagens de FantasmasRESUMO
BACKGROUND: Voxel-based morphometry (VBM) using magnetic resonance imaging (MR) has been used to estimate cortical atrophy associated with various diseases. However, there are mis-segmentations of segmented gray matter image in VBM. PURPOSE: To study a twofold evaluation of single- and multi-channel segmentation using synthetic MR images: (1) mis-segmentation of segmented gray matter images in transverse and cavernous sinuses; and (2) accuracy and repeatability of segmented gray matter images. MATERIAL AND METHODS: A total of 13 healthy individuals were scanned with 3D quantification using an interleaved Look-Locker acquisition sequence with a T2 preparation pulse (3D-QALAS) sequence on a 1.5-T scanner. Three of the 13 healthy participants were scanned five consecutive times for evaluation of repeatability. We used SyMRI software to create images with three contrasts: T1-weighted (T1W), T2-weighted (T2W), and proton density-weighted (PDW) images. Manual regions of interest (ROI) on T1W imaging were individually set as the gold standard in the transverse sinus, cavernous sinus, and putamen. Single-channel (T1W) and multi-channel (T1W + T2W, T1W + PDW, and T1W + T2W + PDW imaging) segmentations were performed with statistical parametric mapping 12 software. RESULTS: We found that mis-segmentations in both the transverse and cavernous sinuses were large in single-channel segmentation compared with multi-channel segmentations. Furthermore, the accuracy of segmented gray matter images in the putamen was high in both multi-channel T1W + PDW and T1W + T2W + PDW segmentations compared with other segmentations. Finally, the highest repeatability of left putamen volumetry was found with multi-channel segmentation T1WI + PDWI. CONCLUSION: Multi-channel segmentation with T1WI + PDWI provides good results for VBM compared with single-channel and other multi-channel segmentations.
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Substância Cinzenta , Putamen , Humanos , Putamen/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , SoftwareRESUMO
Background: Accurate intravascular ultrasound (IVUS) measurements are important in IVUS-guided percutaneous coronary intervention optimization by choosing the appropriate device size and confirming stent expansion. Objectives: The purpose of this study was to assess the accuracy of machine learning (ML) automatic segmentation of coronary artery vessel and lumen dimensions and balloon sizing. Methods: Using expert analysis as the gold standard, ML segmentation of 60 MHz IVUS images was developed using 8,076 IVUS cross-sectional images from 234 patients, which were randomly split into training (83%) and validation (17%) data sets. The performance of ML segmentation was then evaluated using an independent test data set (437 images from 92 patients). The endpoints were the agreement rate between ML vs experts' measurements for appropriate balloon size selection, and lumen and acute stent areas. Appropriate balloon size was determined by rounding down from the mean vessel diameter or rounding up from the mean lumen diameter to the next balloon size. The difference of lumen area ≥0.5 mm2 was considered as clinically significant. Results: ML model segmentation correlated well with experts' segmentation for training data set with a correlation coefficient of 0.992 and 0.993 for lumen and vessel areas, respectively. The agreement rate in lumen and acute stent areas was 85.5% and 97.0%, respectively. The agreement rate for appropriate balloon size selection was 70.6% by vessel diameter only and 92.4% by adding lumen diameter. Conclusions: ML model IVUS segmentation measurements were well-correlated with those of experts and selected an appropriate balloon size in more than 90% of images.
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AIM: Valbenazine is approved in the US for treatment of tardive dyskinesia (TD); however, efficacy/safety data in Asian populations are lacking. We assessed the efficacy/safety of valbenazine in Japanese patients. METHODS: This phase II/III, multicenter, randomized, double-blind, placebo-controlled study (NCT03176771) included adult psychiatric patients with TD, who were randomly allocated to receive placebo or valbenazine (once-daily 40- or 80-mg) for a 6-week, double-blind period, after which the placebo group was switched to valbenazine for a 42-week extension. The primary endpoint was change from baseline in Abnormal Involuntary Movement Scale (AIMS) total score at Week 6; clinical global impression of improvement of TD (CGI-TD) was also assessed. RESULTS: Of 256 patients, 86, 85, and 85 were allocated to the 40-mg valbenazine, 80-mg valbenazine, and placebo groups, respectively. Least-squares mean (95% confidence interval) change from baseline in AIMS score at Week 6 was -2.3 (-3.0 to -1.7) in the valbenazine 40-mg group, -3.7 (-4.4 to -3.0) in the 80-mg group, and -0.1 (-0.8 to 0.5) in the placebo group; both treatment groups showed statistically significant improvements vs. placebo. Patients switched to valbenazine at Week 6 showed similar improvements in AIMS scores, which were maintained to Week 48. Improvements in CGI-TD scores were observed for both treatment groups vs. placebo. Incidence of adverse events was highest in the 80-mg group; common events included nasopharyngitis, somnolence, schizophrenia worsening, hypersalivation, insomnia, and tremor. CONCLUSION: The efficacy/safety profile of valbenazine was similar to that of previous clinical trials, supporting its use for TD treatment in Japanese patients.
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Antipsicóticos , Discinesia Tardia , Adulto , Humanos , Discinesia Tardia/tratamento farmacológico , Discinesia Tardia/induzido quimicamente , Japão , Antipsicóticos/efeitos adversos , Tetrabenazina/efeitos adversos , Método Duplo-Cego , Resultado do TratamentoRESUMO
PURPOSE: In the revised Regulation on Prevention of Ionizing Radiation Hazards (April 2020), the equivalent dose limit for the lens of the eye was lowered to "100 mSv in 5 years and 50 mSv in 1 year." It is necessary to reduce occupational exposure in the healthcare sector. The purpose of this study was to facilitate comparison with the equivalent dose limit in an endoscopic retrograde cholangiopancreatography (ERCP) examination by measuring the scattered dose in an X-ray room as an individual dose equivalent. METHODS: The scattered dose was measured by dosimeters positioned in a grid pattern in the X-ray room. The dose rate was measured with and without the use of a protective cloth (0.25 mm Pb equivalent) suspended around the X-ray tube extending to the patient. The dose reduction rate of the material was evaluated during the simulated ERCP. RESULTS: The maximum dose rate at the position of the surgeon performing an ERCP inspection in the standing position was 2.9 mSv/h (3 mm dose equivalent rate) at 150 cm from the ground. The number of ERCP examinations to comply with the equivalent dose limit of the equivalent dose of the lens of the eye without the protective cloth was 28 per year. CONCLUSION: The results of this study suggest that individual dose equivalent measurements in the X-ray clinic may facilitate comparison with the equivalent dose limit.
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Cristalino , Exposição Ocupacional , Proteção Radiológica , Colangiopancreatografia Retrógrada Endoscópica , Humanos , Exposição Ocupacional/prevenção & controle , Doses de Radiação , Proteção Radiológica/métodos , Raios XRESUMO
Surface-based morphometry (SBM) is extremely useful for estimating the indices of cortical morphology, such as volume, thickness, area, and gyrification, whereas voxel-based morphometry (VBM) is a typical method of gray matter (GM) volumetry that includes cortex measurement. In cases where SBM is used to estimate cortical morphology, it remains controversial as to whether VBM should be used in addition to estimate GM volume. Therefore, this review has two main goals. First, we summarize the differences between the two methods regarding preprocessing, statistical analysis, and reliability. Second, we review studies that estimate cortical morphological changes using VBM and/or SBM and discuss whether using VBM in conjunction with SBM produces additional values. We found cases in which detection of morphological change in either VBM or SBM was superior, and others that showed equivalent performance between the two methods. Therefore, we concluded that using VBM and SBM together can help researchers and clinicians obtain a better understanding of normal neurobiological processes of the brain. Moreover, the use of both methods may improve the accuracy of the detection of morphological changes when comparing the data of patients and controls.In addition, we introduce two other recent methods as future directions for estimating cortical morphological changes: a multi-modal parcellation method using structural and functional images, and a synthetic segmentation method using multi-contrast images (such as T1- and proton density-weighted images).
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Substância Cinzenta , Imageamento por Ressonância Magnética , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Substância Cinzenta/diagnóstico por imagem , Humanos , Reprodutibilidade dos TestesRESUMO
To propose typical values for the arrhythmia region between pulmonary vein isolation (PVI) and nonpulmonary vein isolation (non-PVI) in Japan. A nationwide questionnaire was posted to 343 facilities, to which 125 facilities (36.4%) responded. Results is the median for PVI and non-PVI were in terms of Ka,r (317 and 196 mGy), PKA (40.8 and 26.3 Gy.cm2), FT (43.0 and 27.3 min), and CI (326 and 102 images). When comparing PVI and non-PVI procedures, there were significant differences in Ka, r, PKA, FT, and CI (p < 0.05). In other words, by classifying into two types, PVI and non-PVI, we contributed to the establishment of typical values in Japan's RFCA.
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Fibrilação Atrial , Ablação por Cateter , Veias Pulmonares , Exposição à Radiação , Fibrilação Atrial/cirurgia , Ablação por Cateter/métodos , Humanos , Japão , Veias Pulmonares/cirurgia , Inquéritos e Questionários , Resultado do TratamentoRESUMO
Objective: To meet the new standard of the annual dose limit for the eye lens recommended by the International Commission on Radiation Protection, radiation doses of neuroendovascular procedures in Japanese institutions were investigated. Methods: Radiation doses to operators involved in 304 neuroendovascular procedures at 30 Japanese institutions were prospectively surveyed. The institutions recruited at an annual meeting of the Japanese Society for Neuroendovascular Therapy participated voluntarily. A maximum of 10 wireless dosimeters were attached to the radiation protection (RP) goggles, the ceiling-mounted RP shielding screen, and the operators' forehead and neck over the protective clothing. Doses recorded inside the goggles were defined as eye lens doses for operators who wore RP goggles, while doses to the forehead were defined as eye lens doses for those who did not. The shielding effect rates of the protection devices were calculated, and statistical analysis was performed for the comparison of radiation doses. Results: From 296 analyzed cases, mean eye lens radiation doses per procedure were 0.088 mGy for the left eye and 0.041 mGy for the right eye. For the left eye, that dose without RP equipment was 0.176 mGy and that with RP goggles plus an RP shielding screen was 0.034 mGy. Four parameters, including left eye dose, air kerma at the patient entrance reference point, fluoroscopic time, and the total number of frames, were assessed for five types of neurovascular procedures. Of them, transarterial embolization for dural arteriovenous fistula was associated with the highest eye lens dose at 0.138 mGy. The shielding effect rates of protection goggles were 60% for the left and 55% for the right RP goggle. The mean doses to the inner and outer surfaces of the RP shielding screen were 0.831 mGy and 0.040 mGy, respectively, amounting to a shielding effect rate of 95%. Conclusion: To meet the new standard, both RP goggles and RP shielding screens are strongly recommended to be used effectively. Without proper use of radiological protection devices, the number of neuroendovascular procedures that one operator performs per year will be limited under the new guideline.
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BACKGROUND: Atlas-based volumetry using three-dimensional T1-weighted (3D-T1W) magnetic resonance imaging (MRI) has been used previously to evaluate the volumes of intracranial tissues. PURPOSE: To evaluate the detectability of volume difference and accuracy for volumetry using smoothed data with an atlas-based method. MATERIAL AND METHODS: Twenty healthy individuals and 24 patients with idiopathic normal-pressure hydrocephalus (iNPH) underwent 3-T MRI, and sagittal 3D-T1W images were obtained in all participants. Signal values (as tissue probability) of voxels in five segmented data types (gray matter, white matter, cerebrospinal fluid [CSF], skull, soft tissue) derived from the 3D-T1W images with SPM 12 software were assigned simulated 3D-T1W signal intensities to each tissue image. The assigned data were termed "reference data." We created a reference 3D-T1W image that included the reference data of all five tissue types. Standard volumes were measured for the reference CSF data with region of interest of lateral ventricle in native space, and measured volumes were obtained for non-smoothed and smoothed-modulated data. Detectability was evaluated between measured volumes in the healthy control and iNPH groups. Accuracy was evaluated as the difference between the mean measured and standard volumes. RESULTS: In group comparison of measured volumes between the healthy control and iNPH groups, the lowest P value was for smoothed-modulated CSF data. In both groups, the largest difference from the standard volume was found for the mean of the measured volumes for smoothed-modulated CSF data. CONCLUSION: Our study shows that using smoothed data can improve detectability in group comparison. However, using smoothed data reduces the accuracy of volumetry.
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Hidrocefalia , Processamento de Imagem Assistida por Computador , Encéfalo/diagnóstico por imagem , Substância Cinzenta/diagnóstico por imagem , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Imageamento por Ressonância Magnética/métodos , SoftwareRESUMO
Background: The evolution of radiological technology is one of the most remarkable events of modern medical technology. Radiological examination has resulted in non-invasive, individual diagnostic imaging, which has contributed significantly to successful medical treatment of patients. Key Concepts: This review summarizes past and current Japanese educational systems for radiological technologists with a historical perspective focusing on three periods. The first period begins with Roentgen's discovery of X-rays (1895), the second period begins with the establishment of the Radiological X-ray Technologist Act (1951), and the third period begins with the launch of the first university course for radiological technologists (1987). It is conceivable that those periods are in accordance with the technological paradigm shifts, including the development of contrast radiography and the application of CT and MRI to clinical practice. To maintain awareness of the most recent available technologies and maximize safety, educational programs teaching the latest knowledge were offered during each period. Conclusions: The advanced technologies require highly skilled radiological technologists and highly established educational systems. At present, over 70% of Japanese educational programs for radiological technologists are university courses leading to a bachelor's degree. The increasing globalization of radiological technology requires future radiological education systems to have a global perspective.
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PURPOSE: The aim of this study was to investigate whether the detectability of brain volume change in voxel-based morphometry (VBM) with gray matter images is affected by mild white matter lesions (MWLs). METHODS: Three-dimensional T1-weighted images (3D-T1WIs) of 11 healthy subjects were obtained using a 3T MR scanner. We initially created 3D-T1WIs with focal cortical atrophy simulated cortical atrophy in left amygdala (type A) and the left medial frontal lobe (type B) from control 3D-T1WIs. Next, the following three types of MWL images were created: type A + 1L and type B + 1L images, only one white matter lesion; type A + 4L and type B + 4L images, four white matter lesions at distant positions; and type A + 4L* and type B + 4L* images, four white matter lesions at clustered positions. Comparisons between the control group and the other groups were performed with VBM using segmented gray matter images. RESULTS: The gray matter volume was significantly lower in the type A group than in the control group, and similar results were observed in the type A + 1L, type A + 4L, and type A + 4L* groups. Additionally, the gray matter volume was significantly lower in the type B group than in the control group, and similar results were observed in the type B + 1L, type B + 4L, and type B + 4L* groups, but the cluster size in type B + 4L* was smaller than that in type B. CONCLUSION: Our study showed that the detectability of brain volume change in VBM with gray matter images was not decreased by MWLs as lacunar infarctions. Therefore, we think that group comparisons with VBM should be analyzed by groups including and excluding subjects with MWLs, respectively.
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Encefalopatias , Substância Cinzenta , Imageamento por Ressonância Magnética/métodos , Substância Branca , Encefalopatias/diagnóstico por imagem , Encefalopatias/patologia , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/patologia , Humanos , Imageamento Tridimensional , Substância Branca/diagnóstico por imagem , Substância Branca/patologiaRESUMO
Brain extraction represents an important step in numerous neuroimaging analyses. The brain extraction tool (BET)2 is a widely used deformable model-based approach for extraction of intracranial volume (ICV). The aim of this study is to estimate the ICV extraction accuracy using synthetic MR(SyMRI) method and BET2 in healthy adult participants and patients with Sturge-Weber Syndrome (SWS), including infants. 'Quantification of relaxation times and proton density by multi-echo acquisition of saturation recovery with turbo-spin-echo readout' (QRAPMASTER) with a 3.0 T magnetic resonance image (MRI) system was used for data acquisition. Statistical evaluations were performed with linear regression analysis and the Jaccard similarity coefficient (J). ICV extraction accuracy with synthetic MR method is found to be higher than BET2, for both aged healthy participants and SWS.
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Encéfalo/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador/métodos , Neuroimagem/métodos , Software , Síndrome de Sturge-Weber/diagnóstico por imagem , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Voluntários Saudáveis , Humanos , Lactente , Imageamento por Ressonância Magnética/métodos , MasculinoRESUMO
Japanese Diagnostic Reference Levels (DRLs) were released as "Japan DRLs 2015" from Japan Network for Research and Information on Medical Exposure (J-RIME) in June 2015. In "Japan DRLs 2015", DRLs in angiography and interventional procedures are set at a fluoroscopic dose rate of 20 mGy/min at the interventional reference point using a phantom. In order to achieve optimization with DRLs, then it need to be revised regularly. Therefore, we (research group to examine the effect of Japan DRLs 2015 and the necessity of additional items in angiography and vascular interventions) examined the effects of "Japan DRLs 2015" on angiography and interventional procedures. And we also investigated for DRLs revision in the future. As a result, it turned out that it is important to create DRLs in medical procedures that can be effectively used in clinical settings.