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1.
Clin Neurophysiol ; 158: 170-179, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38219406

RESUMO

OBJECTIVE: Amyloid-beta (Aß) and tau accumulations impair long-term potentiation (LTP) induction in animal hippocampi. We investigated relationships between motor-cortical plasticity and biomarkers for Alzheimer's disease (AD) diagnosis in subjects with cognitive decline. METHODS: Twenty-six consecutive subjects who complained of memory problems participated in this study. We applied transcranial quadripuse stimulation with an interstimulus interval of 5 ms (QPS5) to induce LTP-like plasticity. Motor-evoked potentials were recorded from the right first-dorsal interosseous muscle before and after QPS5. Cognitive functions, Aß42 and tau levels in the cerebrospinal fluid (CSF) were measured. Amyloid positron-emission tomography (PET) with11C-Pittsburg compound-B was also conducted. We studied correlations of QPS5-induced plasticity with cognitive functions or AD-related biomarkers. RESULTS: QPS5-induced LTP-like plasticity positively correlated with cognitive scores. The degree of LTP-like plasticity negatively correlated with levels of CSF-tau, and the amount of amyloid-PET accumulation at the precuneus, and correlated with the CSF-Aß42 level positively. In the amyloid-PET positive subjects, non-responder rate of QPS5 was higher than the CSF-tau positive rate. CONCLUSIONS: Findings suggest that QPS5-induced LTP-like plasticity is a functional biomarker of AD. QPS5 could detect abnormality at earlier stages than CSF-tau in the amyloid-PET positive subjects. SIGNIFICANCE: Assessing motor-cortical plasticity could be a useful neurophysiological biomarker for AD pathology.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Humanos , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/patologia , Proteínas tau/líquido cefalorraquidiano , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Potenciação de Longa Duração/fisiologia , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/líquido cefalorraquidiano , Tomografia por Emissão de Pósitrons , Biomarcadores
2.
J Nucl Med ; 64(12): 1990-1997, 2023 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-37857503

RESUMO

The Omni Legend 32 PET/CT system features silicon photomultiplier (SiPM)-based detectors with bismuth germanium oxide crystals and a 32-cm axial field of view (FOV). The present study aimed to determine the performance characteristics of the Omni Legend 32 PET/CT system according to National Electrical Manufacturers Association (NEMA) NU 2-2018 standards. Methods: The PET component of this system comprises 22 detector modules; each module contains 24 detector blocks with 72 bismuth germanium oxide crystals with a volume of 4.1 × 4.1 × 30 mm coupled to 18 SiPM devices with a 6 × 6 mm area, resulting in an axial FOV of 32 cm. The spatial resolution, sensitivity, count rate performance, and image quality delivered by PET were evaluated using the NEMA NU 2-2018 standard. PET images of 2 patients were evaluated to get a visual first impression of the Omni Legend 32 PET/CT system together with Precision DL. Results: The average spatial resolution at 1, 10, and 20 cm from the central axis was 4.3, 5.3, and 6.2 mm, respectively, for filtered backprojection and 3.7, 4.3, and 5.1 mm, respectively, for ordered-subset expectation maximization. The NEMA sensitivity was 47.30 and 47.05 cps/kBq at the axial center of the FOV and at a 10-cm radial offset, respectively. The scatter fraction, count rate accuracy, and peak noise-equivalent count rates were 35.4%, 1.7%, and 501.7 kcps, respectively, at 15.7 kBq/mL. Contrast recovery for the NEMA body phantom from the smallest to the largest sphere ranged from 61.3% to 93.0%, with a background variability of 5.4%-11.7% and a lung error of 5.1% for Q.Clear (ß-value, 50). Good patient image quality was obtained with the Omni Legend 32. Conclusion: The Omni Legend 32 has class-leading sensitivity and count rates within the category of whole-body PET systems while maintaining spatial resolution broadly comparable to that of other current SiPM-based PET/CT systems. This combination of properties results in a very good image quality.


Assuntos
Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Tomografia por Emissão de Pósitrons , Humanos , Padrões de Referência , Imagens de Fantasmas , Tomografia por Emissão de Pósitrons/métodos
3.
J Physiol Sci ; 73(1): 25, 2023 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-37828449

RESUMO

The regional differences in cerebral oxygen extraction fraction (OEF) in brain were investigated using positron emission tomography (PET) in detail with consideration of systemic errors in PET measurement estimated by simulation studies. The cerebral blood flow (CBF), cerebral blood volume (CBV), OEF, and cerebral metabolic rate of oxygen (CMRO2) were measured on healthy men by PET with 15O-labeled gases. The OEF values in the pons and the parahippocampal gyrus were significantly smaller than in the other brain regions. The OEF value in the lateral side of the occipital cortex was largest among the cerebral cortical regions. Simulation studies have revealed that errors in OEF caused by regional differences in the distribution volume of 15O-labeled water, as well as errors in OEF caused by a mixture of gray and white matter, must be negligible. The regional differences in OEF in brain must exist which might be related to physiological meanings.Article title: Kindly check and confirm the edit made in the article title.I have checked the article title and it is OK as is. Trial registration: The UMIN clinical trial number: UMIN000033382, https://www.umin.ac.jp/ctr/index.htm.


Assuntos
Oxigênio , Tomografia Computadorizada por Raios X , Masculino , Humanos , Oxigênio/metabolismo , Tomografia por Emissão de Pósitrons/métodos , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Córtex Cerebral/metabolismo , Circulação Cerebrovascular/fisiologia , Consumo de Oxigênio/fisiologia
4.
Acta Radiol Open ; 11(2): 20584601221075796, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35251701

RESUMO

BACKGROUND: Whole-body magnetic resonance imaging (WB-MRI) is a useful tool for revealing the disease-specific distribution of affected muscles and clinically asymptomatic muscle involvements in idiopathic inflammatory myopathies (IIMs). PURPOSE: To examine inflammatory changes in the systemic skeletal muscles, including the thoracoabdominal trunk, in IIMs using WB-MRI. MATERIAL AND METHODS: We prospectively obtained WB-MRI axial images from 10 patients with IIMs, including antisynthetase syndrome (ASS), immune-mediated necrotizing myopathy (IMNM), sporadic inclusion body myositis, and myopathy associated with antimitochondrial antibody. We evaluated 108 systemic skeletal muscles in short-tau inversion recovery (STIR) images and rated changes in signal intensity using a semiquantitative scale. Correlations between STIR sum score, peak creatine kinase (CK) and muscle strength were examined. We also investigated the correlation between STIR sum score within the thoracoabdominal trunk and forced vital capacity. RESULTS: High STIR signal changes were frequently identified in asymptomatic and routinely unexamined muscles. Thoracoabdominal trunk muscles were frequently involved in ASS and IMNM. Peak CK was positively correlated with the STIR sum score (R 2 = 0.62, p < .01). There was no significant correlation between the STIR sum score within the thoracoabdominal trunk and forced vital capacity. CONCLUSION: WB-MRI can detect subclinical muscle inflammation in the systemic muscles including the trunk muscles. STIR sum score is positively correlated with serum peak CK level; therefore, it could be a biomarker of overall muscle inflammation.

5.
Fukushima J Med Sci ; 67(3): 161-167, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34937810

RESUMO

A central venous catheter (CVC) should be inserted at the optimum position to infuse medicines, blood products, nutrients, or fluids. Positioning of the catheter tip is commonly performed under landmark or fluoroscopic guidance. However, Japanese regulations do not allow the performing of fluoroscopy-guided procedures outside of the fluoroscopy room. We hypothesized that a new image-guided CVC placement technique by combining a wireless flat-panel detector (FPD) and a mobile X-ray system could be applied at the bedside to support CVC insertion. A CVC attached to a chest phantom in conjunction with the polymethyl methacrylate (PMMA) phantom was imaged, contrast-to-noise ratio (CNR) was measured with images, and radiologists and emergency physicians rated the catheter images using a Likert scale for visual evaluation. The minimum dose of the FPD and mobile X-ray system was reduced by at least 98% compared with that of the X-ray fluoroscopy system. The CNR decreased with the increasing PMMA phantom thickness. However, results of the visual evaluation were maintained at the clinically usable score with low-dose imaging up to a 6-cm thickness of the PMMA phantom. In conclusion, the combination of FPD and mobile X-ray systems is particularly effective in the emergency room setting where such procedures are required to be performed with urgency.


Assuntos
Cateteres Venosos Centrais , Fluoroscopia , Humanos , Imagens de Fantasmas , Doses de Radiação , Raios X
6.
BMC Neurol ; 21(1): 243, 2021 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-34171997

RESUMO

BACKGROUND: Hereditary motor and sensory neuropathy, also referred to as Charcot-Marie-Tooth disease (CMT), is most often caused by a duplication of the peripheral myelin protein 22 (PMP22) gene. This duplication causes CMT type 1A (CMT1A). CMT1A rarely occurs in combination with other hereditary neuromuscular disorders. However, such rare genetic coincidences produce a severe phenotype and have been reported in terms of "double trouble" overlapping syndrome. Waardenburg syndrome (WS) is the most common form of a hereditary syndromic deafness. It is primarily characterized by pigmentation anomalies and classified into four major phenotypes. A mutation in the SRY sex determining region Y-box 10 (SOX10) gene causes WS type 2 or 4 and peripheral demyelinating neuropathy, central dysmyelinating leukodystrophy, WS, and Hirschsprung disease. We describe a 11-year-old boy with extreme hypertrophic neuropathy because of a combination of CMT1A and WS type 2. This is the first published case on the co-occurrence of CMT1A and WS type 2. CASE PRESENTATION: The 11-year-old boy presented with motor developmental delay and a deterioration in unstable walking at 6 years of age. In addition, he had congenital hearing loss and heterochromia iridis. The neurological examination revealed weakness in the distal limbs with pes cavus. He was diagnosed with CMT1A by the fluorescence in situ hybridization method. His paternal pedigree had a history of CMT1A. However, no family member had congenital hearing loss. His clinical manifestation was apparently severe than those of his relatives with CMT1A. In addition, a whole-body magnetic resonance neurography revealed an extreme enlargement of his systemic cranial and spinal nerves. Subsequently, a genetic analysis revealed a heterozygous frameshift mutation c.876delT (p.F292Lfs*19) in the SOX10 gene. He was eventually diagnosed with WS type 2. CONCLUSIONS: We described a patient with a genetically confirmed overlapping diagnoses of CMT1A and WS type 2. The double trouble with the genes created a significant impact on the peripheral nerves system. Severe phenotype in the proband can be attributed to the cumulative effect of mutations in both PMP22 and SOX10 genes, responsible for demyelinating neuropathy.


Assuntos
Doença de Charcot-Marie-Tooth , Proteínas da Mielina/genética , Fatores de Transcrição SOXE/genética , Síndrome de Waardenburg , Doença de Charcot-Marie-Tooth/diagnóstico , Doença de Charcot-Marie-Tooth/genética , Criança , Doenças Desmielinizantes , Duplicação Gênica/genética , Humanos , Masculino , Mutação/genética , Síndrome de Waardenburg/diagnóstico , Síndrome de Waardenburg/genética
7.
Intern Med ; 60(24): 3953-3956, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34121012

RESUMO

A 23-year-old woman was transferred to our hospital due to exacerbating dyspnea with wheeze. After admission, we started mechanical ventilation immediately, and she was diagnosed with status asthmatics. On the following day, she was able to be weaned from the ventilator. However, she required re-intubation because of an unstable respiratory condition just after extubation. Detailed neurological investigations identified blepharoptosis and muscle weakness with easy fatigability. An edrophonium test was positive. Anti-acetylcholine receptor antibody was detected in her serum. She was finally diagnosed with myasthenia gravis and successfully treated with neostigmine and a low-dose corticosteroid.


Assuntos
Miastenia Gravis , Corticosteroides , Adulto , Autoanticorpos , Feminino , Humanos , Miastenia Gravis/complicações , Miastenia Gravis/diagnóstico , Miastenia Gravis/tratamento farmacológico , Receptores Colinérgicos , Respiração Artificial , Adulto Jovem
8.
Nucl Med Commun ; 42(9): 1052-1059, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34001828

RESUMO

OBJECTIVE: This study aimed to evaluate the distribution of Astatine-211 (211At) solution dispersion in a small animal cage using autoradiography imaging to simulate the dispersion of 211At in a lab room to eventually prevent user's risk of internal exposure in terms of radiation safety. METHODS: 211At radiation sources with two chemical properties (Na211At and Free 211At) were prepared. The solutions of 211At were placed onto a dish with paper, and then, it was placed in a small animal cage for 3 h. After removing the dish, an imaging plate with attaching reference sources was placed at four walls of the cage for 15 h in a lead box. Imaging plates were read, and all pixel data were calculated using Microsoft Excel 2016 to obtain three-dimensional (3D) distribution. Calculated results were depicted using a 3D sphere model. RESULTS: The mean activity of Free 211At was 2.3 times higher than that of Na211At on all autoradiography images. In the cage, the shape of the dispersion of Na211At was almost homogeneous, whereas that of Free 211At was more heterogeneous. CONCLUSION: We found that the solution of 211At vaporized naturally and was distributed heterogeneously in the cage, and the chemical properties of 211At influenced their behaviors. These results must be considered to minimize the risks of radiation safety.


Assuntos
Astato , Radioimunoterapia , Autorradiografia , Humanos
9.
Radiol Phys Technol ; 14(1): 70-81, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33400065

RESUMO

The bone cannot be evaluated using magnetic resonance attenuation correction (MRAC) with the Dixon sequence. To solve this issue, the present study aimed to evaluate model-based AC for whole-body 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography (PET)/magnetic resonance imaging (MRI) by creating bone segmentation. We analyzed and evaluated the data of 31 consecutive patients. The Biograph mMR (Siemens Healthcare) was used for clinical whole-body 18F-FDG PET/MRI with the conventional MRAC method, and OSIRIX MD software was used to analyze the images. After the examination, the new model-based post-processing MRAC was applied to create µ-maps with bone segmentation, and retrospective PET reconstruction was performed using this µ-map. The bone structures of all patients created using model-based MRAC were visually evaluated. Standard uptake values (SUVs) at 11 anatomical positions in PET images, corrected using the µ-map with and without bone segmentation, were measured and compared. The model-based post-processing MRAC was run for all patients, without errors. Visual evaluation revealed that the model-based post-processing MRAC exhibited poor results for six patients. Furthermore, it exhibited an increasing trend of SUV in the brain compared to the conventional method. Locations other than the brain indicated a similar or decreasing trend. The two methods showed a good linear correlation for all patients. However, patients aged < 20 years exhibited a different trend from those aged ≥ 20 years. We should exercise caution when applying this model-based MRAC for younger patients.


Assuntos
Fluordesoxiglucose F18 , Imagem Multimodal , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Tomografia por Emissão de Pósitrons , Estudos Retrospectivos
10.
Ann Nucl Med ; 35(4): 421-428, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33502738

RESUMO

OBJECTIVES: Measurement of cerebral blood flow (CBF), cerebral blood volume (CBV), cerebral oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO2) by PET with oxygen-15 labeled gases is useful for diagnosis and treatment planning in cases of chronic occlusive cerebrovascular disease. In the present study, CBF, CBV, OEF and CMRO2 were measured using the integrated design of PET/MRI scanner system. This is a first attempt to measure cerebral perfusion and oxygen metabolism using PET/MRI with oxygen-15 labeled gases. METHODS: PET/MRI measurements with the steady-state method of oxygen-15 labeled gases, carbon monoxide (C15O), oxygen (15O2), and carbon dioxide (C15O2) were performed on nine healthy men. Two kinds of attenuation correction for PET were performed using MRI with Dixon sequence (DIXON) and Dixon sequence with model-based bone segmentation (DIXONbone). A real-time motion correction of PET images was also performed using simultaneously measured MR images to detect head motion. RESULTS: Mean and SD values of CBF, CBV, OEF, and CMRO2 in the cerebral cortices with attenuation correction by DIXON were 31 ± 4 mL/100 mL/min, 2.7 ± 0.2 mL/mL, 0.40 ± 0.07, and 2.5 ± 0.3 mL/100 mL/min without real-time motion correction, and 33 ± 4 mL/100 mL/min, 2.7 ± 0.2 mL/mL, 0.40 ± 0.07, and 2.6 ± 0.3 mL/100 mL/min with real-time motion correction, respectively. Values with of CBF, CBV, OEF, and CMRO2 with attenuation correction by DIXONbone were 35 ± 5 mL/100 mL/min, 2.8 ± 0.2 mL/mL, 0.40 ± 0.07, and 2.8 ± 0.3 mL/100 mL/min without real-time motion correction, and 38 ± 5 mL/100 mL/min, 2.8 ± 0.2 mL/mL, 0.40 ± 0.07, and 3.0 ± 0.4 mL/100 mL/min with real-time motion correction, respectively. CONCLUSIONS: Using PET/MRI with oxygen-15 labeled gases, CBF, CBV, OEF, and CMRO2 could be measured. Values of CBF, CBV, and CMRO2 measured with attenuation correction by DIXON were significantly lower than those measured with correction by DIXONbone. One of the reasons for this is that attenuation correction of DIXON does not take into consideration of the photon absorption by bone. OEF values, corresponding to ratios of CMRO2 to CBF, were not affected by attenuation correction methods. Values of CBF and CMRO2 with a real-time motion correction were significantly higher than those without correction. Using PET/MRI with adequate corrections, similar values of CBF, CBV, OEF, and CMRO2 as PET alone scanner system reported previously were obtained. TRAIL REGISTRATION: The UMIN clinical trial number: UMIN000033382.


Assuntos
Volume Sanguíneo Cerebral/fisiologia , Circulação Cerebrovascular/fisiologia , Transtornos Cerebrovasculares/diagnóstico , Metaboloma/fisiologia , Radioisótopos de Oxigênio/metabolismo , Adulto , Córtex Cerebral/metabolismo , Gases , Humanos , Imageamento por Ressonância Magnética , Masculino , Consumo de Oxigênio/fisiologia , Radioisótopos de Oxigênio/química , Tomografia por Emissão de Pósitrons
11.
EJNMMI Phys ; 7(1): 58, 2020 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-32960387

RESUMO

BACKGROUND: 211At is one of the ideal nuclides for targeted radionuclide therapies (TRTs). Meta-[211At]astatobenzylguanidine (211At-MABG) has been proposed for the treatment of pheochromocytoma. To effectively use these radiopharmaceuticals, dosimetry must be performed. It is important to determine the absorbed doses of free 211At and 211At-MABG to determine the organs that may be at risk when using TRTs. The aim of this study was to estimate human dosimetry from preclinical biodistribution of free 211At and 211At-MABG in various organs in normal mice. METHODS: Male C57BL/6 N mice were administered 0.13 MBq of free 211At or 0.20 MBq of 211At-MABG by tail-vein injection. The mice were sacrificed at 5 min, and at 1, 3, 6, and 24 h after the injection (n = 5 for each group). The percentage of injected activity per mass in organs and blood (%IA/g) was determined. The human absorbed doses of free 211At and 211At-MABG were calculated using the Organ Level INternal Dose Assessment/EXponential Modeling (OLINDA/EXM) version 2.0 and IDAC-Dose 2.1. RESULTS: High uptake of free 211At was observed in the lungs, spleen, salivary glands, stomach, and thyroid. The absorbed doses of free 211At in the thyroid and several tissues were higher than those of 211At-MABG. The absorbed doses of 211At-MABG in the adrenal glands, heart wall, and liver were higher than those of free 211At. CONCLUSIONS: The absorbed doses of 211At-MABG in organs expressing the norepinephrine transporter were higher than those of free 211At. In addition, the biodistribution of free 211At was different from that of 211At-MABG. The absorbed dose of free 211At may help predict the organs potentially at risk during TRTs using 211At-MABG due to deastatination.

12.
Phys Med ; 76: 221-226, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32717701

RESUMO

PURPOSE: This study aimed to compare two methods of assessing the half-value layer (HVL) for computed tomography scanners in a single-rotation technique with and without lead apertures (SRTLA / SRT). METHODS: A 0.6 cc real-time ionization chamber was suspended freely in the air at the isocenter, and six sheets of lead (130 × 170 × 2 mm) were placed at the bottom of the gantry cover, forming five apertures each having a width of 16 mm (SRTLA geometry). Four aluminum plates (100 × 100 mm2; 2.0, 4.0, 6.0, and 8.0 mm thick) were placed on these apertures. Air-kerma rate profiles (K̇air) in the spiral mode were measured at tube potentials of 80, 100, 120, and 135 kVp, a tube current of 100 mA, a nominal beam width of 32.0 mm, and a rotation time of 1.5 s. Thereafter, all lead sheets were removed, and these same measurements were taken to investigate the errors of the HVLs (SRT geometry). HVLs using the SRTLA and SRT were compared with those obtained through a conventional localization technique. RESULTS: The HVLs measured in the SRTLA/SRT at 80, 100, 120, and 135 kVp were 3.37/3.50, 4.24/4.47, 5.22/5.44, and 5.90/6.17 mm, respectively. The differences between these values and those obtained through the conventional technique were 0.09/0.22, 0.02/0.25, 0.05/0.27, and -0.01/0.26 mm, respectively. CONCLUSIONS: The accuracies of the HVLs of the SRTLA were similar to those of the conventional technique. The lead apertures under the aluminum plates would help reduce the number of inaccurate HVL measurements.


Assuntos
Alumínio , Tomografia Computadorizada por Raios X , Doses de Radiação , Rotação , Raios X
13.
Health Phys ; 118(4): 417-426, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32015244

RESUMO

The purpose of this study was to evaluate the kinetic parameters that determine the uptake rate of radioiodide in the thyroid over 24 h after administration and to estimate thyroid volumes/masses of present-day Japanese. Methods: We determined the thyroid uptake rate of I in healthy male Japanese after oral administration (4.5-8.0 MBq) without iodine restriction. Masses of thyroid glands were collected in 2012-2016 during autopsies of 7,651 male and 3,331 female subjects. Volumes of thyroid glands were estimated by ultrasonography and magnetic resonance imaging in 52 male subjects. Results: The thyroid uptake rate of I for 24 h was 16.1 ± 5.4%. Kinetic model analysis was conducted to obtain the clearances (L h) for thyroid uptake and urinary excretion of I (0.499 ± 0.258 and 2.10 ± 0.39 L h, respectively). The masses of thyroid glands were on average 19.8 g (95% confidence interval of 18.3-19.5 g) and 15.5 g (95% confidence interval of 14.7-16.2 g) in male and female subjects aged 19-52 y, respectively. Volumes of thyroid glands estimated by ultrasonography and magnetic resonance imaging were 17.5 ± 5.2 and 14.2 ± 5.3 mL, respectively. In healthy Japanese, there has been no significant change for at least 50 y in the thyroid uptake of radioiodide over 24 h or in its kinetic parameters. These Japanese-specific kinetic parameters will allow quantitative estimation of the radiation exposure from the Fukushima accident and its variance during the individual's evacuation from or stay in Fukushima.


Assuntos
Voluntários Saudáveis , Radioisótopos do Iodo/metabolismo , Glândula Tireoide/anatomia & histologia , Glândula Tireoide/metabolismo , Adulto , Transporte Biológico , Humanos , Japão , Cinética , Imageamento por Ressonância Magnética , Masculino , Método de Monte Carlo , Tamanho do Órgão , Glândula Tireoide/diagnóstico por imagem , Ultrassonografia
14.
J Comput Assist Tomogr ; 43(4): 664-670, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31259851

RESUMO

PURPOSE: To assess the diagnostic ability of whole-body magnetic resonance imaging (MRI) using integrated positron emission tomography/MRI(PET/MRI). METHODS: Axial T2-weighted image (T2WI), diffusion-weighted imaging (DWI), coronal T1-weighted image (T1WI), axial volumetric interpolated breath-hold examination in the lung field, and 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (FDG-PET) were evaluated in combination with T2WI alone, T2WI + DWI, T2WI + DWI + T1WI, T2WI + DWI + T1WI + volumetric interpolated breath-hold examination (all MRI images), and all MRI + FDG-PET. RESULTS: A total of 370 lesions were observed in 90 (62.5%) of the 144 patients. The lesion-based sensitivities were 62%, 74%, 74%, 76%, and 94%, and the patient-based sensitivities were 70%, 77%, 77%, 77%, and 81% using T2WI, T2WI + DWI, T2WI + DWI + T1WI, all MRI, and all MRI + FDG-PET, respectively. There were significant differences in the lesion-based sensitivity between T2WI and other sequence combinations and between all MRI and all MRI + FDG-PET. No significant differences were observed between any combinations among the patient-based sensitivities. CONCLUSION: The sensitivity of whole-body MRI was lower when lesion based, but almost equivalent when patient based compared with PET/MRI.


Assuntos
Imageamento por Ressonância Magnética/métodos , Neoplasias/diagnóstico por imagem , Tomografia por Emissão de Pósitrons/métodos , Imagem Corporal Total/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Fluordesoxiglucose F18/uso terapêutico , Humanos , Interpretação de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Imagem Multimodal , Estudos Retrospectivos , Sensibilidade e Especificidade , Adulto Jovem
15.
Rinsho Shinkeigaku ; 58(11): 692-695, 2018 Nov 28.
Artigo em Japonês | MEDLINE | ID: mdl-30369527

RESUMO

A 33-year-old woman developed progressive weakness in the proximal limbs with myalgia and morning stiffness. Physical examination revealed low-grade fever, heliotrope eyelids and mechanic's hand. On neurological examination, she showed Medical Research Council grade 4 weakness in the shoulder girdle, proximal limb muscles, and grade 4 weakness in the abdominis muscle according to Daniels's scale. Laboratory tests revealed elevated serum creatine kinase (6,824 IU/l) and positive anti-PL-7 antibody. A needle electromyography study detected short motor unit potentials of myogenic pattern with abundant fibrillations and positive sharp waves. Whole-body MRI detected high intensity signals in the muscles of the shoulder girdle, proximal limbs, and thoracoabdominal trunk on short-tau inversion recovery sequence images. We diagnosed her as anti-PL-7 myopathy. After treatments with steroid, immunosuppressant, and immunoglobulin, her symptoms improved and abnormal MRI signals were normalized. Although MRI is known to be useful for detection of asymptomatic muscular inflammation in myositis, thoracoabdominal muscles are generally not covered in routine evaluation. To our knowledge, ours is the first case to detect acute inflammation of the thoracoabdominal muscles in antisynthetase syndrome. The present study suggests that whole-body MRI is useful for comprehensive evaluation of muscular involvement and longitudinal assessment for treatment outcomes.


Assuntos
Aminoacil-tRNA Sintetases/imunologia , Autoanticorpos/sangue , Imageamento por Ressonância Magnética/métodos , Músculo Esquelético/diagnóstico por imagem , Doenças Musculares/diagnóstico por imagem , Doenças Musculares/tratamento farmacológico , Tórax , Imagem Corporal Total/métodos , Músculos Abdominais/diagnóstico por imagem , Adulto , Ciclosporina/administração & dosagem , Feminino , Humanos , Imunoglobulinas Intravenosas/administração & dosagem , Imunossupressores/administração & dosagem , Doenças Musculares/diagnóstico , Doenças Musculares/imunologia , Prednisolona/administração & dosagem , Resultado do Tratamento
16.
J Neurosci ; 38(45): 9679-9688, 2018 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-30249803

RESUMO

Observing mouth movements has strikingly effects on the perception of speech. Any mismatch between sound and mouth movements will result in listeners perceiving illusory consonants (McGurk effect), whereas matching mouth movements assist with the correct recognition of speech sounds. Recent neuroimaging studies have yielded evidence that the motor areas are involved in speech processing, yet their contributions to multisensory illusion remain unclear. Using functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) in an event-related design, we aimed to identify the functional roles of the motor network in the occurrence of multisensory illusion in female and male brains. fMRI showed bilateral activation of the inferior frontal gyrus (IFG) in audiovisually incongruent trials. Activity in the left IFG was negatively correlated with occurrence of the McGurk effect. The effective connectivity between the left IFG and the bilateral precentral gyri was stronger in incongruent than in congruent trials. The McGurk effect was reduced in incongruent trials by applying single-pulse TMS to motor cortex (M1) lip areas, indicating that TMS facilitates the left IFG-precentral motor network to reduce the McGurk effect. TMS of the M1 lip areas was effective in reducing the McGurk effect within the specific temporal range from 100 ms before to 200 ms after the auditory onset, and TMS of the M1 foot area did not influence the McGurk effect, suggesting topographical specificity. These results provide direct evidence that the motor network makes specific temporal and topographical contributions to the processing of multisensory integration of speech to avoid illusion.SIGNIFICANCE STATEMENT The human motor network, including the inferior frontal gyrus and primary motor cortex lip area, appears to be involved in speech perception, but the functional contribution to the McGurk effect is unknown. Functional magnetic resonance imaging revealed that activity in these areas of the motor network increased when the audiovisual stimuli were incongruent, and that the increased activity was negatively correlated with perception of the McGurk effect. Furthermore, applying transcranial magnetic stimulation to the motor areas reduced the McGurk effect. These two observations provide evidence that the motor network contributes to the avoidance of multisensory illusory perception.


Assuntos
Percepção Auditiva/fisiologia , Ilusões/fisiologia , Córtex Motor/fisiologia , Rede Nervosa/fisiologia , Percepção Visual/fisiologia , Estimulação Acústica/métodos , Adolescente , Adulto , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Córtex Motor/diagnóstico por imagem , Rede Nervosa/diagnóstico por imagem , Estimulação Luminosa/métodos , Distribuição Aleatória , Percepção da Fala/fisiologia , Estimulação Magnética Transcraniana/métodos , Adulto Jovem
17.
Artigo em Japonês | MEDLINE | ID: mdl-30033965

RESUMO

A 3D printing emerges as a common procedure in clinical radiology practice after installation of a module that converts the digital imaging and communications in medicine (DICOM) dataset into stereolithography (STL) data on medical workstations. However, they did not conventionally provide the appropriate filtering, sculpting, hollowing out, and Boolean (subtraction) operations on STL data. These functions are indispensable to handle the STL data to fabricate the smooth, low-cost, and sophisticated models. Here are some tips for handling the 3D data with three software packages through making a sample lumbar spine model. Because they are all free- and open-source software with the exception of Boolean operations, they could make it easy for anyone to fabricate their 3D model imaged by CT or MRI. We tested the loop subdivision surface algorithms for the smoothing, the sculpting function for removing a sharp prick, and the hollowing function to save the cost. Computer-aided design (CAD) is also used to fabricate the devices in medical research. We designed and developed a cap attached to a glass dosimeter to show the effectiveness of CAD in radiological research. Lastly, we discuss the important matters for 3D printing and examples of the clinical applications.


Assuntos
Impressão Tridimensional , Tecnologia Radiológica , Desenho Assistido por Computador , Imageamento por Ressonância Magnética , Software
18.
Int Heart J ; 59(3): 626-629, 2018 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-29628471

RESUMO

A cardiac resynchronization therapy defibrillator (CRT-D) (Medtronic Inc. Protecta XT) was implanted in a 67-year-old man who had cardiac sarcoidosis with extremely low cardiac function. He had ventricular tachycardia which was controlled by catheter ablation, medication and pacing. The programmed mode was DDI, lower rate was 90 beats/minute, paced AV delay was 150 ms, and the noncompetitive atrial pacing (NCAP) function was programmed as 300 ms.After his admission for pneumonia and heart failure, we changed his DDI mode to a DDD mode because he had atrial tachycardia, which led to inadequate bi-ventricular pacing. After a while, there were cycle lengths which were longer than his device setting and alternately varied. We were able to avoid this phenomenon with AV delay of 120 ms and NCAP of 200 ms.NCAP is an algorithm which creates a gap above a certain period after the detection of an atrial signal during the postventricular atrial refractory period of the pacemaker. This is to prevent atrial tachycardia and repetitive non-reentrant ventriculoatrial (VA) synchrony in the presence of retrograde VA conduction. But in this case, NCAP algorithm induced much lower rate than the programmed basic lower rate. This situation produced some arrhythmias and exacerbated symptoms of heart failure. This had to be paid attention to, especially when the device was programmed at high basic heart rate.


Assuntos
Arritmias Cardíacas/etiologia , Terapia de Ressincronização Cardíaca/efeitos adversos , Desfibriladores Implantáveis/efeitos adversos , Idoso , Algoritmos , Arritmias Cardíacas/terapia , Terapia de Ressincronização Cardíaca/métodos , Eletrocardiografia , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/terapia , Frequência Cardíaca/fisiologia , Humanos , Masculino
19.
Oncotarget ; 8(33): 55230-55245, 2017 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-28903416

RESUMO

Metastatic renal cell carcinoma (RCC) is a tumor entity with poor prognosis due to limited therapy options. Tyrosine kinase inhibitors (TKI) represent the standard of care for RCCs, however a significant proportion of RCC patients develop resistance to this therapy. Interleukin-6 (IL-6) is considered to be associated with poor prognosis in RCCs. We therefore hypothesized that TKI resistance and IL-6 secretion are causally connected. We first analyzed IL-6 expression after TKI treatment in RCC cells and RCC tumor specimens. Cell proliferation and signal transduction activity were then quantified after co-treatment with tocilizumab, an IL-6R inhibitor, in vitro and in vivo. 786-O RCC cells secrete high IL-6 levels after low dose stimulation with the TKIs sorafenib, sunitinib and pazopanib, inducing activation of AKT-mTOR pathway, NFκB, HIF-2α and VEGF expression. Tocilizumab neutralizes the AKT-mTOR pathway activation and results in reduced proliferation. Using a mouse xenograft model we can show that a combination therapy with tocilizumab and low dosage of sorafenib suppresses 786-O tumor growth, reduces AKT-mTOR pathway and inhibits angiogenesis in vivo more efficient than sorafenib alone. Furthermore FDG-PET imaging detected early decrease of maximum standardized uptake values prior to extended central necrosis. Our findings suggest that a combination therapy of IL-6R inhibitors and TKIs may represent a novel therapeutic approach for RCC treatment.

20.
Neuroimage ; 158: 12-17, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28655632

RESUMO

The central dopaminergic system is of major importance in the pathophysiology of Parkinson's disease, schizophrenia, and other neuropsychiatric disorders. In the present study, the normative data of dopaminergic neurotransmission functions in the midbrain, consisting of neuromelanin, dopamine synthesis, dopamine transporters and dopamine D2 receptors, were constructed using magnetic resonance (MR) imaging and positron emission tomography (PET). PET studies with L-[ß-11C]DOPA, [18F]FE-PE2I and [11C]FLB457 and MRI studies were performed on healthy young men. Neuromelanin accumulation measured by MRI was compared with dopaminergic functions, dopamine synthesis capacity, dopamine transporter binding and dopamine D2 receptor binding measured by PET in the substantia nigra. Although neuromelanin is synthesized from DOPA and dopamine in dopaminergic neurons, neuromelanin accumulation did not correlate with dopamine synthesis capacity in young healthy subjects. The role of dopamine transporters in the substantia nigra is considered to be the transport of dopamine into neurons, and therefore dopamine transporter binding might be related to neuromelanin accumulation; however, no significant correlation was observed between them. A positive correlation between dopamine D2 receptor binding and neuromelanin accumulation was observed, indicating a feedback mechanism by dopaminergic autoreceptors. Discrepancies in regional distribution between neuromelanin accumulation and dopamine synthesis capacity, dopamine transporter binding or dopamine D2 receptor binding were observed in the substantia nigra.


Assuntos
Melaninas/metabolismo , Substância Negra/fisiologia , Transmissão Sináptica/fisiologia , Adulto , Dopamina/metabolismo , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Humanos , Imageamento por Ressonância Magnética , Masculino , Tomografia por Emissão de Pósitrons , Receptores de Dopamina D2/metabolismo , Adulto Jovem
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