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1.
Med Phys ; 2022 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-35535442

RESUMO

Current clinical MR imaging practices rely on the qualitative assessment of images for diagnosis and treatment planning. While contrast in MR images is dependent on the spin parameters of the imaged tissue, pixel values on MR images are relative and are not scaled to represent any tissue properties. Synthetic MR is a fully featured imaging workflow consisting of efficient multiparameter mapping acquisition, synthetic image generation, and volume quantitation of brain tissues. As the application becomes more widely available on multiple vendors and scanner platforms, it has also gained widespread adoption as clinicians begin to recognize the benefits of rapid quantitation. This review will provide details about the sequence with a focus on the physical principles behind its relaxometry mechanisms. It will present an overview of the products in their current form and some potential issues when implementing it in the clinic. It will conclude by highlighting some recent advances of the technique, including a 3D mapping method and its associated applications. This article is protected by copyright. All rights reserved.

2.
Surg Today ; 2022 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-35394206

RESUMO

BACKGROUND AND PURPOSE: We investigated the impact of postoperative changes in the psoas muscle mass index (PMI) after gastrectomy and S1 adjuvant chemotherapy (AC) on the long-term outcomes of elderly patients with gastric cancer. METHODS: We reviewed the medical records of 228 patients aged over 75 years, who underwent distal, proximal, or total gastrectomy between January, 2013 and March 2017. Among these patients, 78 with pStage IIA-IIIC who survived for at least 1 year without recurrence after gastrectomy were the subjects of this analysis. RESULTS: The log-rank test using the cut-off value from the rate of change in PMI from 6 to 12 months after gastrectomy (late rate of decrease) showed significantly poorer prognosis for the group above the cut-off value for both overall survival (OS) and recurrence-free survival (RFS) (RFS: PMI decrease ≥ 1.55%, p < 0.001; OS: PMI decrease ≥ 1.55%, p < 0.001). Patients with a relative dose intensity of S1 below 68.7% and a late rate of decrease in PMI above 1.55% were found to have a poor prognosis. CONCLUSION: It is necessary to prevent decline in the PMI of elderly patients from 6 months after gastrectomy and to administer adjuvant chemotherapy with about two-thirds or more RDI of S1 to improve their survival prognosis.

3.
Neuroimage ; 255: 119176, 2022 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-35390461

RESUMO

PURPOSE: To develop a rigid real-time prospective motion-corrected multiparametric mapping technique and to test the performance of quantitative estimates. METHODS: Motion tracking and correction were performed by integrating single-shot spiral navigators into a multiparametric imaging technique, three-dimensional quantification using an interleaved Look-Locker acquisition sequence with a T2 preparation pulse (3D-QALAS). The spiral navigator was optimized, and quantitative measurements were validated using a standard system phantom. The effect of motion correction on whole-brain T1 and T2 mapping under different types of head motion during the scan was evaluated in 10 healthy volunteers. Finally, six patients with Parkinson's disease, which is known to be associated with a high prevalence of motion artifacts, were scanned to evaluate the effectiveness of our method in the real world. RESULTS: The phantom study demonstrated that the proposed motion correction method did not introduce quantitative bias. Improved parametric map quality and repeatability were shown in volunteer experiments with both in-plane and through-plane motions, comparable to the no-motion ground truth. In real-life validation in patients, the approach showed improved parametric map quality compared to images obtained without motion correction. CONCLUSIONS: Real-time prospective motion-corrected multiparametric relaxometry based on 3D-QALAS provided robust and repeatable whole-brain multiparametric mapping.

4.
Int J Clin Oncol ; 27(5): 930-939, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35344118

RESUMO

BACKGROUND: Little is known about the disadvantages of the coronavirus disease 2019 (COVID-19) pandemic in patients with gastric cancer. This study aimed to examine the negative impact of the COVID-19 pandemic on patients with gastric cancer in the first era in Japan. METHODS: This retrospective study included 725 patients diagnosed with gastric cancer who visited our hospital between April 2019 and March 2021. The number of patients and their characteristics before and during the COVID-19 pandemic were compared. RESULTS: The number of patients diagnosed with gastric cancer during the COVID-19 pandemic decreased by 26.2% (from 417 to 308; p = 0.013) compared to that before the COVID-19 pandemic. There was a significant decrease in cStage I cancer and an increase in cStage III cancer (p = 0.004). Patients were often symptomatic (p = 0.029), especially those with stenosis-related symptoms (p < 0.001) and longer symptom duration (p < 0.001). The number of endoscopic resections was decreased by 34.8% (p = 0.005). The number of total gastrectomy was higher than that of partial gastrectomy (p = 0.021). The median time to treatment was significantly shorter (p < 0.001). CONCLUSIONS: In Japan, delays diagnosing patients with gastric cancer, probably due to refraining from consultation, may have resulted in an increase in the diagnosis of advanced-stage cancer. Moreover, an increasing proportion of patients required more invasive gastrectomy. Therefore, it may be necessary to educate patients not to refrain from consultation, even during the COVID-19 pandemic, as it can have a negative impact on treatment, policy decision, and prognosis of gastric cancer.


Assuntos
COVID-19 , Neoplasias Gástricas , COVID-19/epidemiologia , Humanos , Japão/epidemiologia , Pandemias , Estudos Retrospectivos , SARS-CoV-2 , Neoplasias Gástricas/terapia
5.
J Neurol Sci ; 436: 120205, 2022 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-35259556

RESUMO

INTRODUCTION: Despite differences in the pathogenesis and treatment of multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD), it remains difficult to distinguish them. In this study, we aimed to discriminate between MS and NMOSD using diffusion tensor imaging (DTI), free water (FW) imaging, and neurite orientation dispersion and density imaging (NODDI). METHODS: Thirty patients with relapsing-remitting (RR) MS, 18 NMOSD patients with positive anti-aquaporin-4 immunoglobulin G seroreactivity, and 20 age- and sex- matched currently healthy subjects underwent MRI. The differences in the DTI (fractional anisotropy [FA], axial diffusivity [AD], mean diffusivity [MD], and radial diffusivity [RD]), FW and FW-corrected DTI, and NODDI indices between the three groups were evaluated using tract-based spatial statistics (TBSS) and region-of-interest (ROI) analyses. RESULTS: The ROI analysis of lesions indicated that the RRMS group had significantly higher AD, MD, RD, ISO and FW-corrected AD, and MD; and lower intracellular volume fraction (ICVF) than the NMOSD group. TBSS analysis showed increased water content in RRMS patients compared to NMOSD patients. Compared with healthy controls (HCs) using TBSS and ROI analysis, the changes in FW imaging indices were more limited than those of in DTI in RRMS patients. CONCLUSION: FW imaging and NODDI were useful for identifying the etiology of neurodegeneration- and neuroinflammation-related microstructural changes in RRMS and NMOSD patients.


Assuntos
Leucoaraiose , Esclerose Múltipla Recidivante-Remitente , Esclerose Múltipla , Neuromielite Óptica , Substância Branca , Imagem de Tensor de Difusão/métodos , Humanos , Esclerose Múltipla/patologia , Esclerose Múltipla Recidivante-Remitente/diagnóstico por imagem , Esclerose Múltipla Recidivante-Remitente/patologia , Neuromielite Óptica/diagnóstico por imagem , Neuromielite Óptica/patologia , Água , Substância Branca/diagnóstico por imagem , Substância Branca/patologia
6.
Sci Rep ; 12(1): 4750, 2022 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-35306514

RESUMO

Some herbivorous insects possess the ability to synthesize phytohormones and are considered to use them for manipulating their host plants, but how these insects acquired the ability remains unclear. We investigated endogenous levels of auxin (IAA) and cytokinins (iP and tZ), including their ribosides (iPR and tZR), in various terrestrial arthropod taxa. Surprisingly, IAA was detected in all arthropods analysed. In contrast, tZ and/or tZR was detected only in some taxa. Endogenous levels of IAA were not significantly different among groups with different feeding habits, but gall inducers possessed significantly higher levels of iPR, tZ and tZR. Ancestral state reconstruction of the ability to synthesize tZ and tZR revealed that the trait has only been acquired in taxa containing gall inducers. Our results strongly suggest critical role of the cytokinin synthetic ability in the evolution of gall-inducing habit and IAA has some function in arthropods.


Assuntos
Artrópodes , Citocininas , Animais , Ácidos Indolacéticos , Reguladores de Crescimento de Plantas , Plantas
7.
J Neurosci Res ; 100(7): 1395-1412, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35316545

RESUMO

Herein, we combined neurite orientation dispersion and density imaging (NODDI) and synthetic magnetic resonance imaging (SyMRI) to evaluate the spatial distribution and extent of gray matter (GM) microstructural alterations in patients with relapsing-remitting multiple sclerosis (RRMS) and neuromyelitis optica spectrum disorder (NMOSD). The NODDI (neurite density index [NDI], orientation dispersion index [ODI], and isotropic volume fraction [ISOVF]) and SyMRI (myelin volume fraction [MVF]) measures were compared between age- and sex-matched groups of 30 patients with RRMS (6 males and 24 females; mean age, 51.43 ± 8.02 years), 18 patients with anti-aquaporin-4 antibody-positive NMOSD (2 males and 16 females; mean age, 52.67 ± 16.07 years), and 19 healthy controls (6 males and 13 females; mean age, 51.47 ± 9.25 years) using GM-based spatial statistical analysis. Patients with RRMS showed reduced NDI and MVF and increased ODI and ISOVF, predominantly in the limbic and paralimbic regions, when compared with healthy controls, while only increases in ODI and ISOVF were observed when compared with NMOSD. Compared to NDI and MVF, the changes in ODI and ISOVF were observed more widely, including in the cerebellar cortex. These abnormalities were associated with disease progression and disability. In contrast, patients with NMOSD only showed reduced NDI mainly in the cerebellar, limbic, and paralimbic cortices when compared with healthy controls and patients with RRMS. Taken together, our study supports the notion that GM pathologies in RRMS are distinct from those of NMOSD. However, owing to the limitations of the study, the results should be cautiously interpreted.

8.
Front Neurol ; 13: 814768, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35280291

RESUMO

Differentiating corticobasal degeneration presenting with corticobasal syndrome (CBD-CBS) from progressive supranuclear palsy with Richardson's syndrome (PSP-RS), particularly in early stages, is often challenging because the neurodegenerative conditions closely overlap in terms of clinical presentation and pathology. Although volumetry using brain magnetic resonance imaging (MRI) has been studied in patients with CBS and PSP-RS, studies assessing the progression of brain atrophy are limited. Therefore, we aimed to reveal the difference in the temporal progression patterns of brain atrophy between patients with CBS and those with PSP-RS purely based on cross-sectional data using Subtype and Stage Inference (SuStaIn)-a novel, unsupervised machine learning technique that integrates clustering and disease progression modeling. We applied SuStaIn to the cross-sectional regional brain volumes of 25 patients with CBS, 39 patients with typical PSP-RS, and 50 healthy controls to estimate the two disease subtypes and trajectories of CBS and PSP-RS, which have distinct atrophy patterns. The progression model and classification accuracy of CBS and PSP-RS were compared with those of previous studies to evaluate the performance of SuStaIn. SuStaIn identified distinct temporal progression patterns of brain atrophy for CBS and PSP-RS, which were largely consistent with previous evidence, with high reproducibility (99.7%) under cross-validation. We classified these diseases with high accuracy (0.875) and sensitivity (0.680 and 1.000, respectively) based on cross-sectional structural brain MRI data; the accuracy was higher than that reported in previous studies. Moreover, SuStaIn stage correctly reflected disease severity without the label of disease stage, such as disease duration. Furthermore, SuStaIn also showed the genialized performance of differentiation and reflection for CBS and PSP-RS. Thus, SuStaIn has potential for improving our understanding of disease mechanisms, accurately stratifying patients, and providing prognoses for patients with CBS and PSP-RS.

9.
Eur Radiol ; 2022 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-35304637

RESUMO

OBJECTIVES: We aimed to investigate the influence of magnetic resonance fingerprinting (MRF) dictionary design on radiomic features using in vivo human brain scans. METHODS: Scan-rescans of three-dimensional MRF and conventional T1-weighted imaging were performed on 21 healthy volunteers (9 males and 12 females; mean age, 41.3 ± 14.6 years; age range, 22-72 years). Five patients with multiple sclerosis (3 males and 2 females; mean age, 41.2 ± 7.3 years; age range, 32-53 years) were also included. MRF data were reconstructed using various dictionaries with different step sizes. First- and second-order radiomic features were extracted from each dataset. Intra-dictionary repeatability and inter-dictionary reproducibility were evaluated using intraclass correlation coefficients (ICCs). Features with ICCs > 0.90 were considered acceptable. Relative changes were calculated to assess inter-dictionary biases. RESULTS: The overall scan-rescan ICCs of MRF-based radiomics ranged from 0.86 to 0.95, depending on dictionary step size. No significant differences were observed in the overall scan-rescan repeatability of MRF-based radiomic features and conventional T1-weighted imaging (p = 1.00). Intra-dictionary repeatability was insensitive to dictionary step size differences. MRF-based radiomic features varied among dictionaries (overall ICC for inter-dictionary reproducibility, 0.62-0.99), especially when step sizes were large. First-order and gray level co-occurrence matrix features were the most reproducible feature classes among different step size dictionaries. T1 map-derived radiomic features provided higher repeatability and reproducibility among dictionaries than those obtained with T2 maps. CONCLUSION: MRF-based radiomic features are highly repeatable in various dictionary step sizes. Caution is warranted when performing MRF-based radiomics using datasets containing maps generated from different dictionaries. KEY POINTS: • MRF-based radiomic features are highly repeatable in various dictionary step sizes. • Use of different MRF dictionaries may result in variable radiomic features, even when the same MRF acquisition data are used. • Caution is needed when performing radiomic analysis using data reconstructed from different dictionaries.

10.
Cereb Cortex ; 2022 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-35271703

RESUMO

Relaxation times and morphological information are fundamental magnetic resonance imaging-derived metrics of the human brain that reflect the status of the underlying tissue. Magnetic resonance fingerprinting (MRF) enables simultaneous acquisition of T1 and T2 maps inherently aligned to the anatomy, allowing whole-brain relaxometry and morphometry in a single scan. In this study, we revealed the feasibility of 3D MRF for simultaneous brain structure-wise morphometry and relaxometry. Comprehensive test-retest scan analyses using five 1.5-T and three 3.0-T systems from a single vendor including different scanner types across 3 institutions demonstrated that 3D MRF-derived morphological information and relaxation times are highly repeatable at both 1.5 T and 3.0 T. Regional cortical thickness and subcortical volume values showed high agreement and low bias across different field strengths. The ability to acquire a set of regional T1, T2, thickness, and volume measurements of neuroanatomical structures with high repeatability and reproducibility facilitates the ability of longitudinal multicenter imaging studies to quantitatively monitor changes associated with underlying pathologies, disease progression, and treatments.

11.
Acta Radiol ; : 2841851221089835, 2022 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-35350871

RESUMO

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.

12.
Magn Reson Med Sci ; 21(1): 58-70, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-35173096

RESUMO

Diffusion tensor imaging (DTI) has been established its usefulness in evaluating normal-appearing white matter (NAWM) and other lesions that are difficult to evaluate with routine clinical MRI in the evaluation of the brain and spinal cord lesions in multiple sclerosis (MS), a demyelinating disease. With the recent advances in the software and hardware of MRI systems, increasingly complex and sophisticated MRI and analysis methods, such as q-space imaging, diffusional kurtosis imaging, neurite orientation dispersion and density imaging, white matter tract integrity, and multiple diffusion encoding, referred to as advanced diffusion MRI, have been proposed. These are capable of capturing in vivo microstructural changes in the brain and spinal cord in normal and pathological states in greater detail than DTI.This paper reviews the current status of recent advanced diffusion MRI for assessing MS in vivo as part of an issue celebrating two decades of magnetic resonance in medical sciences (MRMS), an official journal of the Japanese Society of Magnetic Resonance in Medicine.


Assuntos
Esclerose Múltipla , Substância Branca , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Imagem de Difusão por Ressonância Magnética/métodos , Imagem de Tensor de Difusão/métodos , Humanos , Imageamento por Ressonância Magnética , Esclerose Múltipla/diagnóstico por imagem , Esclerose Múltipla/patologia , Medula Espinal/diagnóstico por imagem , Substância Branca/diagnóstico por imagem , Substância Branca/patologia
13.
Magn Reson Med Sci ; 21(1): 41-57, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-35185061

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 Testes
14.
Jpn J Clin Oncol ; 52(5): 456-465, 2022 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-35079828

RESUMO

BACKGROUND: Although the novel coronavirus disease 2019 did not lead to a serious medical collapse in Japan, its impact on treatment of oesophageal cancer has rarely been investigated. This study aimed to investigate the influence of the pandemic on consultation status and initial treatment in patients with primary oesophageal cancer. METHODS: A retrospective study was conducted among 546 patients with oesophageal cancer who visited our hospital from April 2018 to March 2021. Pre-pandemic and pandemic data were compared with the clinical features, oncological factors and initial treatment as outcome measures. RESULTS: Diagnoses of oesophageal cancer decreased during the early phase of the pandemic from April to June (P = 0.048); however, there was no significant difference between the pre-pandemic and pandemic periods throughout the year. The proportion of patients diagnosed with distant metastases significantly increased during the pandemic (P = 0.026), while the proportion of those who underwent initial radical treatment decreased (P = 0.044). The rate of definitive chemoradiotherapy decreased by 58.6% relative to pre-pandemic levels (P = 0.001). CONCLUSIONS: Patients may have refrained from consultation during the early phase of the coronavirus disease 2019 pandemic. The resultant delay in diagnosis may have led to an increase in the number of patients who were not indicated for radical treatment, as well as a decrease in the number of those who underwent definitive chemoradiotherapy. Our findings highlight the need to maintain the health care system and raise awareness on the importance of consultation.


Assuntos
COVID-19 , Neoplasias Esofágicas , COVID-19/epidemiologia , Neoplasias Esofágicas/epidemiologia , Neoplasias Esofágicas/terapia , Humanos , Pandemias , Doenças Raras , Estudos Retrospectivos , SARS-CoV-2 , Tóquio/epidemiologia
15.
Surg Today ; 2022 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-35059845

RESUMO

PURPOSE AND BACKGROUND: Gastrectomy for gastric cancer in overweight patients is associated with a high incidence of postoperative complications and difficulties in achieving adequate lymph node dissection. We conducted this study to compare the outcomes of laparoscopic and open distal gastrectomy (ODG) for gastric cancer in overweight Japanese patients. METHODS: This retrospective study analyzed data from 180 patients with a body mass index ≥ 25 who underwent distal gastrectomy for pStage I-III gastric cancer. Postoperative complications, the number of harvested lymph nodes, and long-term survival were compared between ODG and laparoscopic distal gastrectomy (LDG). RESULTS: Postoperative complications of Clavien-Dindo (CD) grade ≥ 2 and ≥ 3 were significantly higher after ODG than after LDG (p < 0.001 and p = 0.004). Multivariate analysis identified age and ODG as factors related to complications of CD ≥ 2 (p = 0.014 and 0.002). The number of harvested lymph nodes at region 4sb was significantly higher in LDG for patients with pStage III disease. The 5-year lymph node recurrence-free survival tended to be better in LDG; however, no difference was found between ODG and LDG at any pathological stage. There were no significant differences in the 5-year overall and recurrence-free survival rates after ODG vs. LDG. CONCLUSIONS: LDG for gastric cancer appears to be associated with a lower incidence of postoperative complications than ODG, without compromising long-term survival, even for overweight patients.

16.
BMC Surg ; 22(1): 5, 2022 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-34996411

RESUMO

BACKGROUND: The frequency of gallstones is higher in patients who have undergone gastrectomy than in the general population. While there have been some studies of gallstone formation after open gastrectomy, there are few reports of gallstones after laparoscopic gastrectomy (LG). Therefore, this study aimed to evaluate the incidence of gallstones after LG. METHODS: We retrospectively reviewed the records of 184 patients who underwent LG between January 2011 and May 2016 at Saiseikai Utsunomiya Hospital. After gastrectomy, abdominal ultrasonography was generally performed every 6 months for 5 years. Patients who underwent cholecystectomy before LG, underwent simultaneous cholecystectomy, and did not undergo abdominal ultrasonography, with an observation period of < 24 months, were excluded from the study. Finally, 90 patients were analyzed. Laparoscopic cholecystectomy was performed whenever biliary complications occurred. Patient characteristics were compared using the two-tailed Fisher's exact test or Chi-square test. In addition, the risk factors for postoperative gallstones were analyzed using logistic regression analysis. RESULTS: Among the 90 patients included in this study, 60 were men (78%), and the mean age was 65.5 years. Laparoscopic total gastrectomy was performed for 15 patients and laparoscopic distal gastrectomy for 75 patients. D2 lymph node dissection was performed for 8 patients (9%), whereas 68 patients underwent LG with Roux-en-Y reconstruction (76%). Gallstones were detected after LG in 27 of the 90 (30%) patients. Multivariate analysis identified Roux-en-Y reconstruction and male sex as significant risk factors of gallstones after gastrectomy. The incidence of gallstones was significantly higher (53%) in male patients who underwent Roux-en-Y reconstruction. Symptomatic gallstones after laparoscopic cholecystectomy were found in 6 cases (6/27, 22%), and all patients underwent laparoscopic cholecystectomy. CONCLUSION: Roux-en-Y reconstruction and male sex were identified as significant risk factors for gallstones after LG.


Assuntos
Cálculos Biliares , Laparoscopia , Neoplasias Gástricas , Idoso , Cálculos Biliares/diagnóstico por imagem , Cálculos Biliares/epidemiologia , Cálculos Biliares/etiologia , Gastrectomia/efeitos adversos , Humanos , Laparoscopia/efeitos adversos , Masculino , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Estudos Retrospectivos , Fatores de Risco , Neoplasias Gástricas/epidemiologia , Neoplasias Gástricas/cirurgia
17.
Neuroradiology ; 64(3): 465-471, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34383123

RESUMO

PURPOSE: We hypothesize that myelin is more susceptible to damage over time than axons. We investigated the association between the estimated duration from the onset of multiple sclerosis (MS) plaques and myelin- and axon-related quantitative synthetic magnetic resonance imaging (SyMRI) and neurite orientation dispersion and density imaging (NODDI) metrics. METHODS: We analyzed 31 patients with MS with 73 newly appeared plaques. Simple linear regression analysis was performed to assess the association between the estimated duration from the onset of plaques and quantitative MRI metrics. These metrics included the myelin volume fraction (MVF), axon volume fraction, and g-ratio in plaque and normal-appearing white matter. RESULTS: MS plaques with a longer estimated duration from onset were significantly correlated with a lower MVF (slope = - 0.0070, R2 = 0.0970), higher g-ratio (slope = 0.0078, R2 = 0.0842) (all P values < 0.05). CONCLUSION: These results suggested that myelin in plaques undergoes continuous damage, more so than axons. Myelin imaging with SyMRI and NODDI may be useful for the quantitative assessment of temporal changes in MS plaques.


Assuntos
Esclerose Múltipla , Substância Branca , Axônios/patologia , Benchmarking , Encéfalo/patologia , Estudos Transversais , Humanos , Imageamento por Ressonância Magnética/métodos , Esclerose Múltipla/diagnóstico por imagem , Esclerose Múltipla/patologia , Bainha de Mielina/patologia , Substância Branca/patologia
18.
Magn Reson Med Sci ; 2021 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-34897147

RESUMO

PURPOSE: Myelination-related MR signal changes in white matter are helpful for assessing normal development in infants and children. A rule-based myelination evaluation workflow regarding signal changes on T1-weighted images (T1WIs) and T2-weighted images (T2WIs) has been widely used in radiology. This study aimed to simulate a rule-based workflow using a stacked deep learning model and evaluate age estimation accuracy. METHODS: The age estimation system involved two stacked neural networks: a target network-to extract five myelination-related images from the whole brain, and an age estimation network from extracted T1- and T2WIs separately. A dataset was constructed from 119 children aged below 2 years with two MRI systems. A four-fold cross-validation method was adopted. The correlation coefficient (CC), mean absolute error (MAE), and root mean squared error (RMSE) of the corrected chronological age of full-term birth, as well as the mean difference and the upper and lower limits of 95% agreement, were measured. Generalization performance was assessed using datasets acquired from different MR images. Age estimation was performed in Sturge-Weber syndrome (SWS) cases. RESULTS: There was a strong correlation between estimated age and corrected chronological age (MAE: 0.98 months; RMSE: 1.27 months; and CC: 0.99). The mean difference and standard deviation (SD) were -0.15 and 1.26, respectively, and the upper and lower limits of 95% agreement were 2.33 and -2.63 months. Regarding generalization performance, the performance values on the external dataset were MAE of 1.85 months, RMSE of 2.59 months, and CC of 0.93. Among 13 SWS cases, 7 exceeded the limits of 95% agreement, and a proportional bias of age estimation based on myelination acceleration was exhibited below 12 months of age (P = 0.03). CONCLUSION: Stacked deep learning models automated the rule-based workflow in radiology and achieved highly accurate age estimation in infants and children up to 2 years of age.

19.
Magn Reson Med Sci ; 2021 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-34511577

RESUMO

Oscillating-gradient spin-echo sequences enable the measurement of diffusion weighting with a short diffusion time and can provide indications of internal structures. We report two cases of brain abscess in which the apparent diffusion coefficient (ADC) values appear higher at short diffusion times in comparison with those at long diffusion times. Diffusion time dependence of the ADC in brain abscesses suggests not only substrate viscosity but also restricted diffusion due to the structure within the lesions.

20.
Artigo em Inglês | MEDLINE | ID: mdl-34233067

RESUMO

AIM: This study aimed to compare the efficacy of taxane-based and platinum-based regimens in patients with early recurrent gastric cancer after radical surgery with S-1 adjuvant chemotherapy. METHODS: The medical records of 118 patients from six institutes with early recurrent stage II/III gastric cancer, who developed recurrence during adjuvant S-1 or within 6 months after completion of adjuvant therapy between January 2006 and December 2017, were retrospectively analyzed. Patients treated with second line chemotherapy were enrolled and followed to the end of December 2019. The impact of two regimens, taxane-based (n = 46) versus platinum-based (n = 31), on treatment outcome were evaluated using multivariate analysis. RESULTS: Median overall survival was 9.0 months and median progression-free survival was 4.1 months. No difference was observed in overall survival between taxane-based and platinum-based regimens (P = 0.64). Although not significant, the response rate of platinum-based regimens was better than that of taxane-based regimens (16% vs. 6.5%, P = 0.26). Multivariate analysis identified performance status (P = 0.040), multiorgan metastases (P = 0.029), and undifferentiated histological type (P = 0.018) as independent poor prognostic factors. In undifferentiated histological type, multiorgan metastases (P = 0.013) and taxane-based regimens (P = 0.018) were independent prognosis factors characterized by multivariate analysis. Conversion rate to third-line chemotherapy or more was 51% in undifferentiated histological type and 65% in differentiated histological type (P = 0.26). CONCLUSION: Platinum-based regimens may be recommended for undifferentiated early recurrent gastric cancer after S-1 adjuvant chemotherapy.

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