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1.
Radiology ; 306(1): 270-278, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36098641

RESUMEN

Background COVID-19 vaccination-related axillary lymphadenopathy has become an important problem in cancer imaging. Data are needed to update or support imaging guidelines for conducting appropriate follow-up. Purpose To investigate the prevalence, predisposing factors, and MRI characteristics of COVID-19 vaccination-related axillary lymphadenopathy. Materials and Methods Prospectively collected prevaccination and postvaccination chest MRI scans were secondarily analyzed. Participants who underwent two doses of either the Pfizer-BioNTech or Moderna COVID-19 vaccine and chest MRI from June to October 2021 were included. Enlarged axillary lymph nodes were identified on postvaccination MRI scans compared with prevaccination scans. The lymph node diameter, signal intensity with T2-weighted imaging, and apparent diffusion coefficient (ADC) of the largest enlarged lymph nodes were measured. These values were compared between prevaccination and postvaccination MRI by using the Wilcoxon signed-rank test. Results Overall, 433 participants (mean age, 65 years ± 11 [SD]; 300 men and 133 women) were included. The prevalence of axillary lymphadenopathy in participants 1-14 days after vaccination was 65% (30 of 46). Participants with lymphadenopathy were younger than those without lymphadenopathy (P < .001). Female sex and the Moderna vaccine were predisposing factors (P = .005 and P = .003, respectively). Five or more enlarged lymph nodes were noted in 2% (eight of 433) of participants. Enlarged lymph nodes greater than or equal to 10 mm in the short axis were noted in 1% (four of 433) of participants. The median signal intensity relative to the muscle on T2-weighted images was 4.0; enlarged lymph nodes demonstrated a higher signal intensity (P = .002). The median ADC of enlarged lymph nodes after vaccination in 90 participants was 1.1 × 10-3 mm2/sec (range, 0.6-2.0 × 10-3 mm2/sec), thus ADC values remained normal. Conclusion Axillary lymphadenopathy after the second dose of the Pfizer-BioNTech or Moderna COVID-19 vaccines was frequent within 2 weeks after vaccination, was typically less than 10 mm in size, and had a normal apparent diffusion coefficient. © RSNA, 2022.


Asunto(s)
COVID-19 , Linfadenopatía , Masculino , Femenino , Humanos , Anciano , Vacunas contra la COVID-19 , Vacuna nCoV-2019 mRNA-1273 , Sensibilidad y Especificidad , COVID-19/patología , Imagen por Resonancia Magnética/métodos , Ganglios Linfáticos/patología , Vacunación
2.
Gan To Kagaku Ryoho ; 50(13): 1774-1776, 2023 Dec.
Artículo en Japonés | MEDLINE | ID: mdl-38303203

RESUMEN

The case is a woman in her 60s. Sigmoid colon cancer surgery, liver metastasis surgery, and adjuvant chemotherapy were performed at another hospital 2 years ago. Later, she developed a metastasis in her liver and was recommended surgery, but she refused treatment and was transferred. Her liver metastasis had invaded the stomach and formed a giant gastric ulcer. This time she had an adhesive ileus and underwent laparoscopic surgery at our hospital. At that time, we observed the state of liver metastasis and gastric infiltration by laparoscopy, so we thought that palliative surgery was possible and recommended it. Although she initially refused treatment, the relative ease with which her ileus surgery was performed encouraged her to undergo palliative surgery. Laparoscopic-assisted gastrectomy and partial hepatectomy were performed, and she was discharged on hospital day 13 after surgery. She subsequently developed liver metastases and died 8 months after palliative surgery, although she was able to eat and maintain her ADL until the end of life. By staying close to the patient, we were able to lead the patient from refusal of surgery to palliative surgery, and we felt that we were able to make the patient reach a favorable end.


Asunto(s)
Ileus , Neoplasias Hepáticas , Neoplasias del Colon Sigmoide , Femenino , Humanos , Ileus/etiología , Ileus/cirugía , Neoplasias Hepáticas/secundario , Neoplasias del Colon Sigmoide/tratamiento farmacológico , Estómago/patología , Persona de Mediana Edad , Anciano
3.
Bioorg Med Chem Lett ; 41: 128011, 2021 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-33811993

RESUMEN

Photodegradation of azilsartan produces a phenanthridine derivative, with its molecular structure determined by 1H and 13C NMR spectroscopy. This structure is confirmed by single-crystal X-ray diffraction and alternative synthesis. The phenanthridine ring formation is explained through the ring closure of an imidoylnitrene intermediate produced by decarboxylation of the 5-oxo-1,2,4-oxadiazole ring (oxadiazolone).


Asunto(s)
Bencimidazoles/química , Oxadiazoles/química , Cristalografía por Rayos X , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Estructura Molecular , Fenantridinas/síntesis química , Fenantridinas/química , Procesos Fotoquímicos
4.
BMC Med Inform Decis Mak ; 21(1): 262, 2021 09 11.
Artículo en Inglés | MEDLINE | ID: mdl-34511100

RESUMEN

BACKGROUND: It is essential for radiologists to communicate actionable findings to the referring clinicians reliably. Natural language processing (NLP) has been shown to help identify free-text radiology reports including actionable findings. However, the application of recent deep learning techniques to radiology reports, which can improve the detection performance, has not been thoroughly examined. Moreover, free-text that clinicians input in the ordering form (order information) has seldom been used to identify actionable reports. This study aims to evaluate the benefits of two new approaches: (1) bidirectional encoder representations from transformers (BERT), a recent deep learning architecture in NLP, and (2) using order information in addition to radiology reports. METHODS: We performed a binary classification to distinguish actionable reports (i.e., radiology reports tagged as actionable in actual radiological practice) from non-actionable ones (those without an actionable tag). 90,923 Japanese radiology reports in our hospital were used, of which 788 (0.87%) were actionable. We evaluated four methods, statistical machine learning with logistic regression (LR) and with gradient boosting decision tree (GBDT), and deep learning with a bidirectional long short-term memory (LSTM) model and a publicly available Japanese BERT model. Each method was used with two different inputs, radiology reports alone and pairs of order information and radiology reports. Thus, eight experiments were conducted to examine the performance. RESULTS: Without order information, BERT achieved the highest area under the precision-recall curve (AUPRC) of 0.5138, which showed a statistically significant improvement over LR, GBDT, and LSTM, and the highest area under the receiver operating characteristic curve (AUROC) of 0.9516. Simply coupling the order information with the radiology reports slightly increased the AUPRC of BERT but did not lead to a statistically significant improvement. This may be due to the complexity of clinical decisions made by radiologists. CONCLUSIONS: BERT was assumed to be useful to detect actionable reports. More sophisticated methods are required to use order information effectively.


Asunto(s)
Procesamiento de Lenguaje Natural , Radiología , Humanos , Modelos Logísticos , Aprendizaje Automático , Radiografía
5.
J Orthop Sci ; 26(1): 86-91, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32107133

RESUMEN

PURPOSE: To determine the underlying anatomical characteristics in patients with cervical spondylotic radiculopathy (CSR) by comparing those of surgically treated CSR patients with those of healthy subjects. METHODS: Computed tomography (CT) scans of the cervical spine in 42 patients who underwent decompression surgery for CSR were investigated. As a control group, 42 age- and sex-matched healthy subjects were randomly selected from the 1272 subjects who underwent CT examinations of the entire spine as their routine medical check-up. Image measurements included C2-7 sagittal Cobb angle, spinal canal diameters, and angles of the nerve root groove at each level from C3 to C7, and the size of the intervertebral foramen and the size of osteophytes at each level from C3/4 to C7/T1. As for the frequency of osteophytes at the surgical level, we compared the operated and nonoperated intervertebral foramina among the CSR patients, and all other parameters were compared with the corresponding segments in the control group. RESULTS: Forty-eight intervertebral segments were surgically treated in the CSR group. There was a higher incidence of osteophytes in the operated foramen (70.8%) than in the nonoperated foramen (28.2%, p < 0.01) in the patients with CSR. The anteroposterior diameter (width) of the foramen was significantly smaller at all levels in the CSR patients, whereas the height of the foramen did not significantly differ between the two groups. CONCLUSION: It can be speculated that the width of the intervertebral foramen (developmental factor) and the formation of osteophytes (spondylotic factor) were related to the onset of the CSR.


Asunto(s)
Radiculopatía , Espondilosis , Vértebras Cervicales/diagnóstico por imagen , Vértebras Cervicales/cirugía , Femenino , Humanos , Masculino , Radiculopatía/diagnóstico por imagen , Radiculopatía/etiología , Radiculopatía/cirugía , Canal Medular , Espondilosis/complicaciones , Espondilosis/diagnóstico por imagen , Espondilosis/cirugía , Tomografía Computarizada por Rayos X
6.
J Digit Imaging ; 34(2): 418-427, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33555397

RESUMEN

The purposes of this study are to propose an unsupervised anomaly detection method based on a deep neural network (DNN) model, which requires only normal images for training, and to evaluate its performance with a large chest radiograph dataset. We used the auto-encoding generative adversarial network (α-GAN) framework, which is a combination of a GAN and a variational autoencoder, as a DNN model. A total of 29,684 frontal chest radiographs from the Radiological Society of North America Pneumonia Detection Challenge dataset were used for this study (16,880 male and 12,804 female patients; average age, 47.0 years). All these images were labeled as "Normal," "No Opacity/Not Normal," or "Opacity" by board-certified radiologists. About 70% (6,853/9,790) of the Normal images were randomly sampled as the training dataset, and the rest were randomly split into the validation and test datasets in a ratio of 1:2 (7,610 and 15,221). Our anomaly detection system could correctly visualize various lesions including a lung mass, cardiomegaly, pleural effusion, bilateral hilar lymphadenopathy, and even dextrocardia. Our system detected the abnormal images with an area under the receiver operating characteristic curve (AUROC) of 0.752. The AUROCs for the abnormal labels Opacity and No Opacity/Not Normal were 0.838 and 0.704, respectively. Our DNN-based unsupervised anomaly detection method could successfully detect various diseases or anomalies in chest radiographs by training with only the normal images.


Asunto(s)
Redes Neurales de la Computación , Radiografía Torácica , Femenino , Humanos , Masculino , Persona de Mediana Edad , Curva ROC , Radiografía , Radiólogos
7.
Photochem Photobiol Sci ; 19(11): 1517-1521, 2020 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-33047774

RESUMEN

Solid-state photoinduced coloring of boronium complexes consisting of 9-borabicyclononane and 2,2'-bipyridine with π-conjugated substituents at the 4,4'- or 5,5'-positions was investigated. The substitution position affected the highest occupied molecular orbital distribution and determined the coloring capability. The 4,4'-substituted complexes exhibited coloration upon irradiation, whereas most of the 5,5'-substituted complexes did not.

8.
Eur Spine J ; 29(3): 579-585, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31578637

RESUMEN

PURPOSE: Associated factors for and the natural course of sacroiliac (SI) joint degeneration in the normal population are unknown. The purpose of this study was to determine associated factors for and the progression rate of SI joint degeneration. METHODS: We enrolled 553 healthy middle-aged subjects who underwent the first and second comprehensive health screening at an interval of 5.9 years (range 3.0-10.7 years). The medical checkup included blood tests and whole-body computed tomography. We investigated associated factors of SI joint degeneration, the relationship of the laterality of degeneration between the SI and L4/5 facet joint, L5/S facet joint, and the natural course of SI joint degeneration over time. RESULTS: At the first checkup, 70 subjects (12.7%) showed substantial degeneration (type 2 or 3) of the SI joints. Multivariate analysis revealed that female sex; pubic symphysis degeneration, L4/5, and L5/S facet joint degeneration; high body mass index; and several blood parameters were associated factors for SI joint degeneration. Laterality of SI joint degeneration was significantly more frequent than that of L4/5 or L5/S facet joint degeneration. Kaplan-Meier survival analysis revealed that the progression rates of SI joint degeneration from type 0 (no degeneration) or type 1 (slight degeneration) to substantial degeneration amounted to 3.4% and 35.5% after 10 years, respectively. CONCLUSION: We found substantial SI joint degeneration in 12.7% of healthy middle-aged subjects and considered it to be part of the normal aging process. There may be individual factors associated with its occurrence. These slides can be retrieved under Electronic Supplementary Material.


Asunto(s)
Articulación Sacroiliaca , Espondilosis , Articulación Cigapofisaria , Femenino , Humanos , Vértebras Lumbares , Masculino , Persona de Mediana Edad , Articulación Sacroiliaca/diagnóstico por imagen , Articulación Sacroiliaca/patología , Tomografía Computarizada por Rayos X
9.
Int J Obes (Lond) ; 43(1): 169-175, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-29777233

RESUMEN

OBJECTIVES: Obesity is increasing in developed countries and is a risk factor for pancreatic cancer (PaC). We previously reported that obesity was associated with pancreatic cystic lesions (PCLs), which are both precursors of, and risk factors for, PaC. In the present study, we further investigated the relationship between visceral adiposity and adiponectin levels and the extent of PCLs. METHODS: Individuals who underwent comprehensive health screening at our institution between January 2008 and March 2013 were analyzed. PCLs were diagnosed via magnetic resonance imaging using a 3.0 Tesla system. The volumes of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were measured from computed tomographic volume data. Serum levels of adiponectin were measured using a sandwich enzyme-linked immunosorbent assay. RESULTS: The prevalences of PCLs were 14.2% in males (N = 2683; mean age, 56.4 years) and 16.2% in females (N = 1741; mean age, 57.1 years). The prevalence of PCLs increased gradually as VAT volume increased (P < 0.001). PCLs were more prevalent in individuals with high adiponectin levels (18.7% vs. 13.8%, P = 0.005). VAT volume (odds ratio [OR] for the highest quartiles, 1.52 [1.07-2.16]; P = 0.025) and adiponectin level (OR for the highest quartiles, 1.31 [1.08-1.59]; P = 0.007) but not SAT volume (P = 0.828) was significantly associated with PCLs in multivariate analyses. CONCLUSIONS: Visceral adiposity and high adiponectin levels were associated with PCL prevalence. Further work is needed to explore the relationships between visceral adiposity and adiponectin levels, and PCLs and PaC.


Asunto(s)
Adiponectina/sangre , Grasa Intraabdominal/metabolismo , Obesidad Abdominal/sangre , Quiste Pancreático/patología , Anciano , Estudios Transversales , Femenino , Humanos , Grasa Intraabdominal/diagnóstico por imagen , Japón/epidemiología , Masculino , Tamizaje Masivo , Persona de Mediana Edad , Obesidad Abdominal/diagnóstico por imagen , Obesidad Abdominal/epidemiología , Obesidad Abdominal/fisiopatología , Quiste Pancreático/diagnóstico por imagen , Quiste Pancreático/epidemiología , Prevalencia , Factores de Riesgo , Tomografía Computarizada por Rayos X
10.
J Orthop Sci ; 24(6): 1074-1080, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31521453

RESUMEN

BACKGROUND: It is important to assess the fracture risk associated with metastasis in the proximal femur. The study aimed to clarify the effect of tumor location on the risk of pathological fracture of the proximal femur and investigate the fracture risk not only in the stance-loading configuration (SC), but also in the fall-loading configuration (FC) using a computed tomography (CT)-based finite element (FE) method based on a simulated metastatic model. METHODS: The axial CT scans of the proximal femora of non-osteoporotic healthy men (n = 4; age range, 42-48 years) and osteoporotic post-menopausal women (n = 4; age range, 69-78 years) were obtained with a calibration phantom, from which the three-dimensional FE models were constructed. A single 15-mm-diameter spherical void simulating a tumor was created at various locations from the neck to subtrochanteric level. Nonlinear FE analyses were performed. RESULTS: The mean predicted fracture loads without spherical voids in the SC were 7700 N in men and 4370 N in women. With the void at the medial femoral neck and in the region anteromedial to lesser trochanter, the mean predicted fracture load significantly reduced to 51.3% and 59.4% in men and 34.1% and 64.5% in women, respectively. The mean predicted fracture loads without a spherical void in the FC were 2500 N in men and 1862 N in women. With the void at the medial and posterior femoral neck, the predicted fracture load was significantly reduced to 65.7% and 79.7% in men and 48.3% and 65.4% in women, respectively. CONCLUSIONS: These results showed that the risk of pathologic fracture was quite high in both the SC and FC when the lytic lesion existed along the principal compressive trabecular trajectory or posterior neck. Prophylactic intervention should be considered for metastases at these locations.


Asunto(s)
Accidentes por Caídas , Neoplasias Femorales/diagnóstico por imagen , Neoplasias Femorales/secundario , Fracturas Espontáneas/diagnóstico por imagen , Fracturas Espontáneas/etiología , Soporte de Peso , Adulto , Anciano , Fenómenos Biomecánicos , Femenino , Análisis de Elementos Finitos , Humanos , Imagenología Tridimensional , Masculino , Persona de Mediana Edad , Modelos Anatómicos , Modelos Biológicos , Factores de Riesgo , Tomógrafos Computarizados por Rayos X
11.
J Magn Reson Imaging ; 47(4): 948-953, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-28836310

RESUMEN

BACKGROUND: The usefulness of computer-assisted detection (CAD) for detecting cerebral aneurysms has been reported; therefore, the improved performance of CAD will help to detect cerebral aneurysms. PURPOSE: To develop a CAD system for intracranial aneurysms on unenhanced magnetic resonance angiography (MRA) images based on a deep convolutional neural network (CNN) and a maximum intensity projection (MIP) algorithm, and to demonstrate the usefulness of the system by training and evaluating it using a large dataset. STUDY TYPE: Retrospective study. SUBJECTS: There were 450 cases with intracranial aneurysms. The diagnoses of brain aneurysms were made on the basis of MRA, which was performed as part of a brain screening program. FIELD STRENGTH/SEQUENCE: Noncontrast-enhanced 3D time-of-flight (TOF) MRA on 3T MR scanners. ASSESSMENT: In our CAD, we used a CNN classifier that predicts whether each voxel is inside or outside aneurysms by inputting MIP images generated from a volume of interest (VOI) around the voxel. The CNN was trained in advance using manually inputted labels. We evaluated our method using 450 cases with intracranial aneurysms, 300 of which were used for training, 50 for parameter tuning, and 100 for the final evaluation. STATISTICAL TESTS: Free-response receiver operating characteristic (FROC) analysis. RESULTS: Our CAD system detected 94.2% (98/104) of aneurysms with 2.9 false positives per case (FPs/case). At a sensitivity of 70%, the number of FPs/case was 0.26. DATA CONCLUSION: We showed that the combination of a CNN and an MIP algorithm is useful for the detection of intracranial aneurysms. LEVEL OF EVIDENCE: 4 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;47:948-953.


Asunto(s)
Angiografía Cerebral/métodos , Interpretación de Imagen Asistida por Computador/métodos , Imagenología Tridimensional/métodos , Aneurisma Intracraneal/diagnóstico por imagen , Angiografía por Resonancia Magnética/métodos , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Sensibilidad y Especificidad
12.
Langmuir ; 33(48): 13797-13804, 2017 12 05.
Artículo en Inglés | MEDLINE | ID: mdl-29119792

RESUMEN

Photoreductive synthesis of colloidal gold nanoparticles (AuNPs) from Au3+ is one important process for nanoprocessing. Several methods have been proposed; however, there is no report of a method capable of producing AuNPs with inexpensive reagents acting as both reductant and surface stabilizer, promoted solely under photoirradiation. We found that UV irradiation of water with Au3+ and benzoic acid successfully produces monodispersed AuNPs, where thermal reduction does not occur in the dark condition even at elevated temperatures. Photoexcitation of a benzoate-Au3+ complex reduces Au3+ while oxidizing benzoic acid. The benzoic acid molecules are adsorbed on the AuNPs and act as surface stabilizers. Change in light intensity and benzoic acid amount successfully creates AuNPs with controllable sizes. The obtained AuNPs can easily be redispersed in an organic solvent or loaded onto a solid support by simple treatments.

13.
J Digit Imaging ; 30(5): 629-639, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28405834

RESUMEN

We propose a generalized framework for developing computer-aided detection (CADe) systems whose characteristics depend only on those of the training dataset. The purpose of this study is to show the feasibility of the framework. Two different CADe systems were experimentally developed by a prototype of the framework, but with different training datasets. The CADe systems include four components; preprocessing, candidate area extraction, candidate detection, and candidate classification. Four pretrained algorithms with dedicated optimization/setting methods corresponding to the respective components were prepared in advance. The pretrained algorithms were sequentially trained in the order of processing of the components. In this study, two different datasets, brain MRA with cerebral aneurysms and chest CT with lung nodules, were collected to develop two different types of CADe systems in the framework. The performances of the developed CADe systems were evaluated by threefold cross-validation. The CADe systems for detecting cerebral aneurysms in brain MRAs and for detecting lung nodules in chest CTs were successfully developed using the respective datasets. The framework was shown to be feasible by the successful development of the two different types of CADe systems. The feasibility of this framework shows promise for a new paradigm in the development of CADe systems: development of CADe systems without any lesion specific algorithm designing.


Asunto(s)
Algoritmos , Diagnóstico por Computador/métodos , Aneurisma Intracraneal/diagnóstico por imagen , Angiografía por Resonancia Magnética/métodos , Nódulos Pulmonares Múltiples/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad
14.
Anal Chem ; 88(13): 6805-11, 2016 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-27268123

RESUMEN

We synthesized a coumarin-spiropyran dyad with a hydrogenated pyran moiety (2), behaving as an off-on type fluorescent receptor for rapid, selective, and sensitive detection of cyanide anion (CN(-)) in aqueous media. The receptor itself shows almost no fluorescence with a quantum yield < 0.01, due to the delocalization of π-electrons over the molecule. Selective nucleophilic addition of CN(-) to the spirocarbon of the molecule rapidly promotes spirocycle opening within only 3 min. This leads to localization of π-electrons on the coumarin moiety and exhibits strong light-blue fluorescence at 459 nm with very high quantum yield (0.52). As a result of this, the receptor facilitates rapid, selective, and sensitive fluorometric detection of CN(-) as low as 1.0 µM.

15.
Circ J ; 80(2): 332-9, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26639068

RESUMEN

BACKGROUND: When the maximal diameter of an abdominal aortic aneurysm (AAA) exceeds a threshold, the likelihood of catastrophic rupture increases markedly. Therefore, surveillance at optimal intervals should be offered to patients with AAA. However, other than AAA diameter, there is no useful marker or index for predicting the expansion rate of an AAA or determining the optimal intervals for surveillance. The aim of this study was to evaluate the usefulness of calcium accumulation in the AAA for predicting its expansion rate. METHODS AND RESULTS: We performed a retrospective cohort study in 414 patients with infrarenal AAA who visited The University of Tokyo Hospital. The maximal diameter and extent of calcification of each AAA were evaluated by multidetector-row computed tomography imaging. There was an inverse correlation between the extent of calcification and the subsequent AAA expansion. A lower extent of calcification in the AAA as well as the AAA diameter and absence of coronary artery disease correlated with an accelerated expansion of the AAA. CONCLUSIONS: In AAA, a lower extent of calcification correlated with accelerated expansion. The calcification index of an AAA can be a useful predictor of its expansion rate. The study findings also support the theory that the mechanisms for progression in atherosclerosis with calcification and external expansion of an aneurysm are distinct.


Asunto(s)
Aneurisma de la Aorta Abdominal/metabolismo , Calcio/metabolismo , Calcificación Vascular/metabolismo , Anciano , Anciano de 80 o más Años , Aneurisma de la Aorta Abdominal/diagnóstico por imagen , Femenino , Estudios de Seguimiento , Humanos , Masculino , Tomografía Computarizada Multidetector/métodos , Estudios Retrospectivos , Calcificación Vascular/diagnóstico por imagen
16.
Mod Rheumatol ; 26(1): 151-5, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-25926424

RESUMEN

OBJECTIVE: The objective of this study was to investigate the factors that affect the predicted bone strength of proximal femur in Japanese population. METHODS: Participants (552 men and 273 women) in a health checkup program with computed tomography (CT) at the University of Tokyo Hospital were enrolled in this study. Three-dimensional finite element models of the proximal femur were constructed from CT data of the participants with simultaneous scans of a calibration phantom containing hydroxyapatite rods. Multiple regression analysis was performed to analyze the relationship between the predicted bone strength and clinical factors. RESULTS: Average predicted strength of proximal femur was lower in women than in men in all age ranges. Predicted bone strength in women under both stance and fall configurations significantly decreased with age, and that in men had the tendency to decrease with age. Body weight positively affected the predicted bone strength in both men and women. CONCLUSIONS: This is the first cross-sectional analysis of the predicted bone strength of the proximal femur in Japanese population of wide age range. Age and body weight critically affected bone strength of proximal femur determined by quantitative CT-based finite element method, in particular in women, under both stance and fall configurations.


Asunto(s)
Fémur/diagnóstico por imagen , Articulación de la Cadera/diagnóstico por imagen , Accidentes por Caídas , Adulto , Distribución por Edad , Factores de Edad , Anciano , Anciano de 80 o más Años , Estudios Transversales , Femenino , Análisis de Elementos Finitos , Humanos , Masculino , Persona de Mediana Edad , Valores de Referencia , Tomografía Computarizada por Rayos X
17.
Neuroimage ; 84: 133-40, 2014 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-23994315

RESUMEN

Interest has recently grown in multi-center studies, which have more power than smaller studies in conducting sophisticated evaluations of basic neuroanatomy and neurodegenerative disorders. The large number of subjects that result from pooling multi-center datasets increases sensitivity, but also introduces a between-center variance component. Taking sex differences as an example, we examined the effects of different ratios of cases to controls (males to females) between scanners in multi-scanner morphometric studies, using voxel-based morphometry and data obtained on two scanners of the exact same model. Each subject was scanned twice with both scanners. Using the image obtained on either of the two scanners for each subject, voxel-based analyses were repeated with different ratios of males to females for each scanner. As the ratio of males to females became more imbalanced between the scanners, the differences between the two scanners more strongly affected the results of analyses of sex differences. When the ratio of males to females was balanced, the inclusion of scanner as a covariate in the statistical analysis had almost no influence on the results of analyses of sex differences. When the ratio of males to females was ill-balanced, the inclusion of scanner as a covariate suppressed scanner effects on the results, but made sex differences less likely to become significant. The present results suggest that as long as the ratio of cases to controls is well-balanced across different scanners, it is not always necessary to include scanner as a covariate in the statistical analysis, and that when the ratio of cases to controls is ill-balanced across scanners, the inclusion of scanner as a covariate in the statistical analysis can suppress scanner effects, but may make differences less likely to be detected.


Asunto(s)
Encéfalo/anatomía & histología , Conectoma/instrumentación , Conectoma/estadística & datos numéricos , Imagen de Difusión Tensora/instrumentación , Imagen de Difusión Tensora/estadística & datos numéricos , Estudios Multicéntricos como Asunto/estadística & datos numéricos , Anciano , Diseño de Equipo , Análisis de Falla de Equipo/estadística & datos numéricos , Femenino , Humanos , Japón , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Distribución por Sexo
18.
J Magn Reson Imaging ; 39(4): 917-23, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24123288

RESUMEN

PURPOSE: To examine sex differences in fractional anisotropy of the white matter across the whole brain, controlling for head size variation. MATERIALS AND METHODS: A total of 238 normal subjects aged 40-49 years were included in this study. Diffusion tensor images were acquired at 3 Tesla using a single-shot spin-echo echo-planar sequence. With use of tract-based spatial statistics (TBSS), sex differences in fractional anisotropy of the white matter were examined across the whole brain, without and with adjustment of total intracranial volume. Voxelwise analyses of the processed fractional anisotropy data were performed using permutation-based, voxelwise nonparametric testing. RESULTS: TBSS analysis without adjustment for total intracranial volume showed several regions with a significant effect of sex on fractional anisotropy; these included the splenium of the corpus callosum, bilateral superior corona radiata, and posterior limbs of the internal capsule, midbrain, and cerebellum. Significantly higher fractional anisotropy was seen in males compared with females in these regions. TBSS analysis with adjustment for total intracranial volume, however, showed a greatly reduced number of such regions. CONCLUSION: The results of our study suggest that sex differences in fractional anisotropy of the white matter reported by previous studies may partly reflect differences in head size, not microscopic differences.


Asunto(s)
Encéfalo/anatomía & histología , Imagen de Difusión Tensora/métodos , Interpretación de Imagen Asistida por Computador/métodos , Imagenología Tridimensional/métodos , Fibras Nerviosas Mielínicas/ultraestructura , Adulto , Anisotropía , Femenino , Humanos , Aumento de la Imagen/métodos , Masculino , Persona de Mediana Edad , Tamaño de los Órganos , Valores de Referencia , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Factores Sexuales
19.
J Magn Reson Imaging ; 39(6): 1426-30, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24129992

RESUMEN

PURPOSE: To investigate the incidence of abnormal signal hyperintensity on T1-weighted magnetic resonance imaging (MRI) of the seminal vesicles in a screening population in order to compare clinical indicators between subjects with and without signal abnormality. MATERIALS AND METHODS: Signal intensity of the seminal vesicles on T1-weighted images and clinical examinations were investigated in 3570 examinations of 1865 male subjects (mean age 54.8 years, range 23-86 years at the first examination). RESULTS: Abnormal signal hyperintensity was observed at least once in 32 subjects (1.7%). Subjects with the abnormality were significantly older (average age with and without the abnormality, 64.1 vs. 54.6, respectively, P < 0.001), and the incidence of abnormality increased with increasing age (0% for the age group <40, 0.3% for 40-49, 1.3% for 50-59, 2.9% for 60-69, 5.9% for 70-79, and 10.1% for >80). No significant difference was found in clinical indicators except for serum creatinine (1.10 vs. 0.84 mg/dL, P < 0.001). Of 12 subjects with abnormal signal intensity and follow-up data, the finding persisted on the same side for at least 11 months in seven subjects (58%). CONCLUSION: Abnormal signal intensity of the seminal vesicles was observed in 1.7% of screening population, and the imaging finding in isolation is unlikely to have clinical significance.


Asunto(s)
Imagen por Resonancia Magnética/métodos , Vesículas Seminales/patología , Adulto , Distribución por Edad , Anciano , Anciano de 80 o más Años , Estudios de Seguimiento , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Estudios Retrospectivos , Adulto Joven
20.
J Magn Reson Imaging ; 39(1): 132-42, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23857823

RESUMEN

PURPOSE: To show the gray matter volumes in the default mode network (DMN) using the atlas-based method and to evaluate age-related volume change in the DMN region. Estimation of gray matter volumes is interesting research because previous reports showed an association with gray matter volume (GMV) and diseases. MATERIALS AND METHODS: We focused on five nodes of the DMN (posterior cingulate, precuneus, lateral temporal cortex [LTC], medial prefrontal cortex, and inferior parietal lobule). In all, 1122 healthy adults were included in the present study. T1-weighted magnetic resonance (MR) images were obtained using a 3T-MR scanner. To investigate GMV in the DMN, segmented gray matter images were measured by the atlas-based method, using Statistical Parametric Mapping 5. Volumes were expressed using three different methods: region of interest (ROI)-volume (mL), the volume itself; ROI-TIV (%), as a percentage of total intracranial volume (individual difference of head size is corrected); and ROI-GMV (%), as a percentage of gray matter volume (individual difference of atrophy speed for aging is corrected). RESULTS: Negative correlations between measurement values on ROI and age were observed in all five ROIs of the DMN region by two measures of volume (ROI-volume (mL) and ROI-TIV (%)), in both genders. In contrast, positive correlations between measurement values on ROI and age were observed in the posterior cingulate and LTC with ROI-GMV (%), in both genders. CONCLUSION: The present study is the first report about volume change in the DMN that includes age-related effects.


Asunto(s)
Envejecimiento , Mapeo Encefálico/métodos , Encéfalo/fisiología , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Femenino , Giro del Cíngulo/patología , Voluntarios Sanos , Humanos , Procesamiento de Imagen Asistido por Computador , Modelos Lineales , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Lóbulo Parietal/patología , Corteza Prefrontal/patología , Lóbulo Temporal/patología
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