RESUMO
OBJECTIVE: The importance of health literacy in medical imaging is well recognized, yet the current landscape remains inadequately understood. This study aims to explore the extent of health literacy studies contextualized to medical imaging. STUDY DESIGN: Scoping review. METHODS: A scoping review was conducted using three online bibliographic databases namely, PubMed, ScienceDirect, and CINAHL. We have adopted the concept of health literacy, as a clinical risk and personal asset, to guide this review. RESULTS: Of 311 unique articles, 39 met our selection criteria. Five themes (categories) were identified by the authors: appropriate communication with patients who receive medical imaging test results, appropriate usage of medical imaging, classes and characteristics of eHealth literacy, disease/deterioration prevention, and patient education. Additionally, 17 health literacy assessment tools were identified, including 11 original creations. Finally, 11 recommendations have emerged from this scoping review, offering valuable insights into methods, considerations, and strategies for promoting health literacy. CONCLUSIONS: Health literacy studies in medical imaging cover both clinical and public health perspectives, benefiting diverse populations, regardless of underlying medical conditions. Notably, the majority of assessment tools used in these studies were author-generated, hindering cross-study comparisons. Given the innate capacity of medical images to convey intuitive information, those images do not solely benefit the patients who are given medical imaging examinations, but they also hold significant potential to enhance public health literacy. Health literacy and medical imaging are closely associated and mutually reinforce each other.
Assuntos
Diagnóstico por Imagem , Letramento em Saúde , Humanos , Diagnóstico por Imagem/estatística & dados numéricos , Educação de Pacientes como AssuntoRESUMO
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.
Assuntos
Substância Cinzenta , Putamen , Humanos , Putamen/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , SoftwareRESUMO
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.
Assuntos
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
The purpose of this study is to investigate changes in lung tumor internal target volume during stereotactic body radiotherapy treatment (SBRT) using magnetic resonance imaging (MRI). Ten lung cancer patients (13 tumors) undergoing SBRT (48 Gy over four consecutive days) were evaluated. Each patient underwent three lung MRI evaluations: before SBRT (MRI-1), after fraction 3 of SBRT (MRI-3), and three months after completion of SBRT (MRI-3m). Each MRI consisted of T1-weighted images in axial plane through the entire lung. A cone-beam CT (CBCT) was taken before each fraction. On MRI and CBCT taken before fractions 1 and 3, gross tumor volume (GTV) was contoured and differences between the two volumes were compared. Median tumor size on CBCT before fractions1 (CBCT-1) and 3 (CBCT-3) was 8.68 and 11.10 cm3, respectively. In 12 tumors, the GTV was larger on CBCT-3 compared to CBCT-1 (median enlargement, 1.56 cm3). Median tumor size on MRI-1, MRI-3, and MRI-3m was 7.91, 11.60, and 3.33 cm3, respectively. In all patients, the GTV was larger on MRI-3 compared to MRI-1 (median enlargement, 1.54 cm3). In all patients, GTV was smaller on MRI-3m compared to MRI-1 (median shrinkage, 5.44 cm3). On CBCT and MRI, all patients showed enlargement of the GTV during the treatment week of SBRT, except for one patient who showed minimal shrinkage (0.86 cm3). Changes in tumor volume are unpredictable; therefore, motion and breathing must be taken into account during treatment planning, and image-guided methods should be used, when treating with large fraction sizes.
Assuntos
Artefatos , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/radioterapia , Imageamento por Ressonância Magnética/métodos , Radiocirurgia/métodos , Radioterapia Guiada por Imagem/métodos , Carga Tumoral , Feminino , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Neoplasias Pulmonares/fisiopatologia , Masculino , Pessoa de Meia-Idade , Movimento (Física) , Reprodutibilidade dos Testes , Mecânica Respiratória , Sensibilidade e Especificidade , Técnica de SubtraçãoRESUMO
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.
Assuntos
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
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.
RESUMO
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).
Assuntos
Óculos Inteligentes , Estudantes de Medicina , Humanos , Avaliação Educacional/métodos , Aprendizagem , Radiografia , Competência ClínicaRESUMO
Motion artefacts caused by the patient's body movements affect magnetic resonance imaging (MRI) accuracy. This study aimed to compare and evaluate the accuracy of motion artefacts correction using a conditional generative adversarial network (CGAN) with an autoencoder and U-net models. The training dataset consisted of motion artefacts generated through simulations. Motion artefacts occur in the phase encoding direction, which is set to either the horizontal or vertical direction of the image. To create T2-weighted axial images with simulated motion artefacts, 5500 head images were used in each direction. Of these data, 90% were used for training, while the remainder were used for the evaluation of image quality. Moreover, the validation data used in the model training consisted of 10% of the training dataset. The training data were divided into horizontal and vertical directions of motion artefact appearance, and the effect of combining this data with the training dataset was verified. The resulting corrected images were evaluated using structural image similarity (SSIM) and peak signal-to-noise ratio (PSNR), and the metrics were compared with the images without motion artefacts. The best improvements in the SSIM and PSNR were observed in the consistent condition in the direction of the occurrence of motion artefacts in the training and evaluation datasets. However, SSIM > 0.9 and PSNR > 29 dB were accomplished for the learning model with both image directions. The latter model exhibited the highest robustness for actual patient motion in head MRI images. Moreover, the image quality of the corrected image with the CGAN was the closest to that of the original image, while the improvement rates for SSIM and PSNR were approximately 26% and 7.7%, respectively. The CGAN model demonstrated a high image reproducibility, and the most significant model was the consistent condition of the learning model and the direction of the appearance of motion artefacts.
Assuntos
Aprendizado Profundo , Humanos , Processamento de Imagem Assistida por Computador/métodos , Artefatos , Reprodutibilidade dos Testes , Imageamento por Ressonância Magnética/métodosRESUMO
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.
Assuntos
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
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.
RESUMO
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).
Assuntos
Substância Cinzenta , Imageamento por Ressonância Magnética , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Substância Cinzenta/diagnóstico por imagem , Humanos , Reprodutibilidade dos TestesRESUMO
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.
Assuntos
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
Computed tomography-guided needle biopsy (CT-GNB) has a high diagnostic yield for lung cancer but higher complication rates compared to those of other biopsy modalities. We sought to clarify in which thoracic lesions we could achieve a quick pathological diagnosis using CT-GNB, considering the risks and benefits. We retrospectively enrolled 110 patients who underwent CT-GNB and 547 patients who underwent transbronchial biopsy (TBB) for parenchymal lung lesions in clinical practice. The diagnostic rates of CT-GNB and TBB were 87.3% and 75.3%. After failed diagnosis with other biopsy modalities, 92.3% of patients were finally diagnosed using CT-GNB and 65.8% using TBB. In cases with a negative bronchial sign, there was a statistically higher diagnostic rate with CT-GNB than with TBB (p < 0.001: 89.4% vs. 0%). Complication rates were higher with CT-GNB (50.9%) than with TBB (16.3%). However, there were lower rates of complications in cases with inhomogeneous tumors, subpleural lesions, and when more than 15 mm of the punctured needle length was within the target. We conclude that CT-GNB is an effective biopsy modality with a high diagnostic rate that is especially recommended when the bronchus sign is negative. It can be safely performed if risk factors for complications are taken into account.
RESUMO
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.
Assuntos
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
The aim of this study was to evaluate the effect of changing the contrast of an analyzed image on the accuracy of intracranial volume (ICV) extraction using the Brain Extraction Tool (BET2) in healthy adults and patients with Sturge-Weber syndrome (SWS), including infants. Twelve SWS patients, including infants, and 12 healthy participants were imaged on a 3.0-T magnetic resonance imaging (MRI) machine. All individuals underwent quantification of relaxation times and proton density using multi-echo acquisition of saturation recovery with turbo-spin-echo readout (QRAPMASTER). Based on the QRAPMASTER data, we created images with seven contrasts (T1-WI, T2-WI, PD-WI, T2 short-tau inversion recovery [STIR], proton density [PD] STIR, T2STIR + PDSTIR, and T1-WI + T2-WI + PD-WI) by post-processing with SyMRI software. ICVs extracted with BET2 from the FMRIB (Functional Magnetic Resonance Imaging of the Brain) Software Library with each of the seven image contrasts were compared with manually extracted ICVs, which is the gold standard reviewed by a board-certificated neuroradiologist. Manual extraction was performed on T1-WI and T2STIR. Statistical analyses were performed with Jaccard similarity coefficients (J). The highest J score was found in T1-WI + T2-WI + PD-WI in all participants (0.8451); T1-WI in healthy participants (0.8984); T2STIR in participants with SWS (0.8325). Our findings suggest that T1-WI and T2STIR should be used in ICV extraction performed using BET2 on healthy participants and infants, respectively. Additionally, if the analyzed individuals include both healthy participants and infants, T1-WI + T2-WI + PD-WI should be used.
Assuntos
Mapeamento Encefálico/métodos , Encéfalo/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , Síndrome de Sturge-Weber/diagnóstico por imagem , Adolescente , Adulto , Criança , Pré-Escolar , Meios de Contraste/farmacologia , Reações Falso-Positivas , Feminino , Humanos , Lactente , Imageamento por Ressonância Magnética , Masculino , Reconhecimento Automatizado de Padrão , Reprodutibilidade dos Testes , Software , Adulto JovemRESUMO
CONTEXT: Although moderate weight reduction is recommended as primary therapy of metabolic syndrome, little information is known regarding metabolic changes associated with moderate weight reduction in nondiabetic obese subjects. OBJECTIVE: The aim of this study was to determine the effects of a moderate weight reduction program on intracellular lipid and glucose metabolism in muscle and liver. PARTICIPANTS: Data for 13 nondiabetic obese subjects were evaluated. INTERVENTION: Subjects were put on a 3-month mildly hypocaloric diet therapy (approximately 35 kcal/kg of ideal body weight). MAIN OUTCOME MEASURES: Intrahepatic lipid (IHL) and intramyocellular lipid were measured by using (1)H magnetic resonance spectroscopy. Peripheral insulin sensitivity and splanchnic glucose uptake were evaluated by euglycemic-hyperinsulinemic clamp with oral glucose load. RESULTS: Diet therapy for 3 months resulted in 6% reduction in body weight (from 99.9 +/- 7.3 to 93.8 +/- 6.6 kg, P < 0.0001). This change was accompanied by reduction of plasma glucose and insulin excursions during 75-g oral glucose tolerance tests, decrease in diastolic blood pressure, glycated hemoglobin, serum low-density lipoprotein cholesterol, and triglyceride. These changes were also accompanied by a decrease in IHL (from 12.9 to 8.2%, P < 0.01) and increase in splanchnic glucose uptake (from 13.5 to 35.0%, P < 0.03). On the other hand, the diet program did not affect intramyocellular lipid or glucose infusion rate during euglycemic hyperinsulinemic clamp. CONCLUSIONS: Our results suggest that moderate weight reduction in obese subjects decreased IHL and augmented splanchnic glucose uptake. This mechanism is at least in part involved in improvement of glucose metabolism by moderate weight reduction in obese subjects.
Assuntos
Glucose/metabolismo , Fígado/metabolismo , Células Musculares/metabolismo , Obesidade/metabolismo , Triglicerídeos/metabolismo , Redução de Peso/fisiologia , Tecido Adiposo/metabolismo , Índice de Massa Corporal , Dieta Redutora , Técnica Clamp de Glucose , Humanos , Resistência à Insulina/fisiologia , Metabolismo dos Lipídeos/fisiologia , Espectroscopia de Ressonância Magnética , Músculo Esquelético/metabolismo , Obesidade/dietoterapiaRESUMO
OBJECTIVES: We investigated changes in the optic tract and optic radiation in patients with multiple sclerosis (MS) by comparing unilateral and bilateral optic nerve damage assessed based on visual evoked potentials (VEPs) using advanced diffusion MR metrics. METHODS: In 21 MS patients, diffusion MRI was performed. Maps of fractional anisotropy, apparent diffusion coefficient (ADC), and mean kurtosis (MK) were computed. On the basis of the P100 latency in VEPs, the MS patients were divided into three groups: bilateral (n=7), unilateral (n=7), and no abnormality (n=7). Their optic tracts and optic radiations were analyzed with diffusion MRI-based fiber tracking. We also investigated the correlations between diffusion parameters and VEPs (n=21). RESULTS: In the optic tract, the diffusion changes in each of the three groups showed step-like changes. The diffusion changes in the optic radiations of the unilateral group were similar to those in the normal VEP group. Only the bilateral group showed significantly higher ADC and lower MK relative to the other two groups (P<0.05, Steel-Dwass multiple-comparison test). A significant positive correlation between VEP latency and ADC and a significant negative correlation between VEP latency and MK were observed (P<0.01, Spearman's correction). CONCLUSIONS: We first evaluated the relationship between VEPs and DKI and concluded that the lateral geniculate nucleus may compensate for unilateral damage in the pre-geniculate optic pathway via neural plasticity.
Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Potenciais Evocados Visuais , Esclerose Múltipla/diagnóstico por imagem , Nervo Óptico/diagnóstico por imagem , Trato Óptico/diagnóstico por imagem , Adulto , Anisotropia , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Fibras Nervosas/patologia , Índice de Gravidade de DoençaRESUMO
Insulin resistance is associated with the circulating free fatty acid (FFA) level and intracellular lipid content in muscle and liver. We investigated the effect of 2-wk diet and exercise therapy on total adiposity, circulating FFA, intracellular lipid content in muscle and liver, and peripheral insulin sensitivity. Type 2 diabetic patients were divided into a diet group (n = 7) and a diet plus exercise group (n = 7). We performed a hyperinsulinemic-euglycemic clamp study before and after treatment. Intramyocellular lipid (IMCL) in the tibialis anterior muscle and intrahepatic lipid (IHL) were evaluated by (1)H-magnetic resonance spectroscopy. Fasting FFA were not altered, and total body fat showed a slight, but significant, decrease in both groups after treatment. IMCL was decreased by 19%, and the glucose infusion rate was increased by 57% in the diet plus exercise group, whereas neither IMCL nor glucose infusion rate was significantly altered in the diet group. However, IHL showed a significant decrease in both groups. In summary, we found that 2 wk of diet and exercise decreased IMCL and increased muscle insulin-mediated glucose uptake, whereas diet with or without exercise decreased IHL. These effects were evident despite a small decrease in body fat and were observed independently of fasting FFA levels.
Assuntos
Diabetes Mellitus Tipo 2/fisiopatologia , Dieta para Diabéticos , Exercício Físico/fisiologia , Metabolismo dos Lipídeos , Fígado/metabolismo , Músculo Esquelético/metabolismo , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Índice de Massa Corporal , Diabetes Mellitus Tipo 2/metabolismo , Feminino , Técnica Clamp de Glucose , Hemoglobinas Glicadas/metabolismo , Humanos , Hiperinsulinismo/sangue , Insulina/farmacologia , Insulina/provisão & distribuição , Testes de Função Hepática , Masculino , Pessoa de Meia-IdadeRESUMO
Aneurysms within renal angiomyolipomas (AML) may rupture into the tumor or pararenal space. Transcatheter arterial embolization is the first-choice treatment to control bleeding. Here, we describe the use of coil embolization in two cases of spontaneous intratumoral hemorrhage with the hemodynamic characteristics of renal arteriovenous (AV) fistula in renal AML. In case 1, renal angiography showed several intratumoral aneurysms, one of which had ruptured into the tumor, resulting in the formation of an intratumoral hematoma. Blood flow within the hematoma was rapid and the blood was immediately returned to the systemic circulation through the left renal vein. In case 2, renal angiography showed that the rupture of an intratumoral aneurysm of a tumor-feeding artery had resulted in formation of an intratumoral hematoma and direct renal vein communication. No extratumoral hemorrhage was observed in either case. The hemodynamics of both hematomas resembled those of a high-flow renal AV fistula. The ruptured aneurysms were embolized with detachable and pushable coils (case 1) or pushable coils only (case 2). To our knowledge, this is the first report of successful embolization of AV fistula-like intratumoral hemorrhage in renal AML.