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1.
Sensors (Basel) ; 24(5)2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38475156

ABSTRACT

A new nondestructive inspection method, the magnetic hammer test (MHT), which uses a compact and highly sensitive tunnel magnetoresistance (TMR) sensor, is proposed. This method complements the magnetic flux leakage method and eliminates the issues of the hammer test. It can therefore detect weak magnetic fields generated by the natural vibration of a pipe with a high signal-to-noise ratio. In this study, several steel pipes with different wall thicknesses were measured using a TMR sensor to demonstrate the superiority of MHT. The results of the measurement show that wall thickness can be evaluated with the accuracy of several tens of microns from the change in the natural vibration frequency of the specimen pipe. The pipes were also inspected underwater using a waterproofed TMR sensor, which demonstrated an accuracy of less than 100 µm. The validity of these results was by simulating the shielding of magnetic fields and vibration of the pipes with the finite element method (FEM) analysis. The proposed noncontact, fast, and accurate method for thickness testing of long-distance pipes will contribute to unmanned, manpower-saving nondestructive testing (NDT) in the future.

2.
Microorganisms ; 9(4)2021 Apr 08.
Article in English | MEDLINE | ID: mdl-33917715

ABSTRACT

The aim of this study was to determine whether human herpesvirus 6B (HHV-6B) infection can impair the hippocampus in pediatric hematopoietic stem cell transplant (HSCT) recipients. Study subjects were pediatric HSCT recipients monitored for HHV-6B infection who underwent brain MRI before and after transplantation. Volumetric analysis of the hippocampus was performed. Of the 107 patients that received HSCT at Nagoya University Hospital Between July 2008 and April 2014, 20 were eligible for volumetric analysis. Eight patients had HHV-6B infection, of whom two had encephalopathy at the time of HHV-6B infection. None of the 12 patients without HHV-6B infection had encephalopathy. The median ratio of the right hippocampal volume from before to after transplantation was 0.93 in patients with HHV-6B infection and 1.02 in without HHV-6B infection (p = 0.007). The median ratio of the left hippocampal volume ratio in patients with and without HHV-6B infection was 0.92 and 1.00, respectively (p = 0.003). Among the eight patients with HHV-6B infection, four had a marked reduction in hippocampal volume (volume ratio < 0.90). Only one of these patients had neurological symptoms at the time of HHV-6B infection. The reduction in the hippocampal volume ratio was higher in pediatric HSCT recipients with HHV-6B infection than those without viral infection. Neurological follow-up may be required for pediatric HSCT recipients with HHV-6B infection.

3.
Fujita Med J ; 6(4): 102-109, 2020.
Article in English | MEDLINE | ID: mdl-35111530

ABSTRACT

OBJECTIVE: This study aimed to clarify the relationship between interprofessional self-evaluation and peer evaluation during interprofessional education (IPE) using team-based learning (TBL). We also aimed to clarify differences in interprofessional cooperation between students with high and low peer evaluation scores. METHODS: In total, 483 students (grades 3-5) from nine faculties at three universities participated in a TBL-based IPE program. The students completed five interprofessional self-evaluation domains (the modified Tsukuba IPE model) before and after IPE. Students also completed peer evaluation after IPE. Students were divided into three groups by peer evaluation scores (low, middle, high), and the post-class self-evaluation scores of these groups were compared using a Kruskal-Wallis test. Multiple regression analysis was also performed. Peer evaluation comments were analyzed using a qualitative inductive method. RESULTS: Students in the low peer evaluation group had significantly lower scores in the "Regarding participation in group work" domain than students in the high group (P<0.05). Students in the high group received positive comments, such as [good communication] and [working cooperatively], whereas students in the low group were required to improve in two areas: [speaking up more] and [need more communication]. CONCLUSIONS: There was a significant relationship between peer evaluation by team members and self-evaluation for "Regarding participation in group work." Students with high peer evaluation scores participated with active attitudes, whereas students with low scores were considered passive. This study suggested that using peer evaluation may enhance students' professional cooperation by improving their communication and attitudes toward active participation.

4.
Jpn J Radiol ; 37(4): 283-291, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30706382

ABSTRACT

PURPOSE: Diagnostic and neurosurgical procedures require the precise localization of small intracranial arteries, but this may be difficult using conventional computed tomography angiography (CTA). This study was conducted to evaluate the quality of CTA images acquired using a prototype ultra-high-resolution computed tomography (U-HRCT) system compared with those acquired using a conventional computed tomography (C-CT) system. MATERIALS AND METHODS: From July through September 2015, 10 adult patients (6 women and 4 men) previously scanned by C-CT were examined using U-HRCT to locate and assess cerebral aneurysms. The bilateral ophthalmic artery (Opth A), anterior choroidal artery (Acho A), and thalamoperforating arteries (TPAs) were visually evaluated in randomly presented CTA images. Images were graded on a 5-point scale, and differences in scores between U-HRCT and C-CT were evaluated by the Wilcoxon signed-rank test. A p value < 0.05 was considered statistically significant. RESULTS: Visual evaluation scores for images of the Opth A, Acho A, and TPAs were significantly higher for U-HRCT than for C-CT. U-HRCT images achieved good visualization (score > 3) for C-CT images with poor visualization (score < 3) in 66.7-100% of all the small arteries. CONCLUSION: U-HRCT is superior to C-CT for detecting and evaluating clinically significant small intracranial arteries.


Subject(s)
Cerebral Angiography/methods , Cerebral Arteries/diagnostic imaging , Computed Tomography Angiography/methods , Image Processing, Computer-Assisted/methods , Intracranial Aneurysm/diagnostic imaging , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Reproducibility of Results
5.
Medicine (Baltimore) ; 97(9): e9906, 2018 Mar.
Article in English | MEDLINE | ID: mdl-29489691

ABSTRACT

Noncontrast computed tomography (NCCT) has been used for the detection of early ischemic change (EIC); however, correct interpretation of NCCT findings requires much clinical experience. This study aimed to assess the accuracy of time maximum intensity projection computed tomography technique (tMIP), which reflects the maximum value for the time phase direction from the dynamic volume data for each projected plane, for detection of EIC, against that of NCCT.Retrospective review of NCCT, cerebral blood volume in CT perfusion (CTP-CBV), and tMIP of 186 lesions from 280 regions evaluated by Alberta Stroke Program Early CT Score (ASPECTS) in 14 patients with acute middle cerebral artery stroke who had undergone whole-brain CTP using 320-row area detector CT was performed. Four radiologists reviewed EIC on NCCT, CTP-CBV, and tMIP in each ASPECTS region at onset using the continuous certainty factor method. Receiver operating characteristic analysis was performed to compare the relative performance for detection of EIC. The correlations were evaluated.tMIP-color showed the best discriminative value for detection of EIC. There were significant differences in the area under the curve for NCCT and tMIP-color, CTP-CBV (P < .05). Scatter plots of ASPECTS showed a positive significant correlation between NCCT, tMIP-gray, tMIP-color, and the follow-up study (NCCT, r = 0.32, P = .0166; tMIP-gray, r = 0.44, P = .0007; tMIP-color, r = 0.34, P = .0104).Because tMIP provides a high contrast parenchymal image with anatomical and vascular information in 1 sequential scan, it showed greater accuracy for detection of EIC and predicted the final infarct extent more accurately than NCCT based on ASPECTS.


Subject(s)
Brain Ischemia/diagnostic imaging , Infarction, Middle Cerebral Artery/diagnostic imaging , Stroke/diagnostic imaging , Tomography, X-Ray Computed/statistics & numerical data , Aged , Aged, 80 and over , Area Under Curve , Brain/blood supply , Cerebrovascular Circulation , Female , Follow-Up Studies , Humans , Male , ROC Curve , Retrospective Studies , Time Factors , Tomography, X-Ray Computed/methods
6.
Radiol Phys Technol ; 10(2): 148-154, 2017 Jun.
Article in English | MEDLINE | ID: mdl-27645287

ABSTRACT

The purposes of this study were (1) to compare the radiation doses for 320- and 80-row fetal-computed tomography (CT), estimated using thermoluminescent dosimeters (TLDs) and the ImPACT Calculator (hereinafter referred to as the "CT dosimetry software"), for a woman in her late pregnancy and her fetus and (2) to estimate the overlapped fetal radiation dose from a 320-row CT examination using two different estimation methods of the CT dosimetry software. The direct TLD data in the present study were obtained from a previous study. The exposure parameters used for TLD measurements were entered into the CT dosimetry software, and the appropriate radiation dose for the pregnant woman and her fetus was estimated. When the whole organs (e.g., the colon, small intestine, and ovaries) and the fetus were included in the scan range, the difference in the estimated doses between the TLD measurement and the CT dosimetry software measurement was <1 mGy (<23 %) in both CT units. In addition, when the whole organs were within the scan range, the CT dosimetry software was used for evaluating the fetal radiation dose and organ-specific doses for the woman in the late pregnancy. The conventional method using the CT dosimetry software cannot take into account the overlap between volumetric sections. Therefore, the conventional method using a 320-row CT unit in a wide-volume mode might result in the underestimation of radiation doses for the fetus and the colon, small intestine, and ovaries.


Subject(s)
Fetus/radiation effects , Monte Carlo Method , Radiation Dosage , Tomography, X-Ray Computed , Female , Humans , Pregnancy , Radiation Exposure/analysis , Radiometry , Software
7.
Radiat Prot Dosimetry ; 168(4): 523-30, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26224738

ABSTRACT

The purpose of this study was to evaluate the maternal and foetal effective doses during foetal computed tomography (CT) and to compare the radiation dose, dose profile and image noise on 80-row CT in helical scanning mode and 320-row CT in wide-volume scanning mode. The radiation doses were measured using thermoluminescent dosemeters implanted at various organ sites of an anthropomorphic pregnant phantom. The foetal doses in the 320-row multi-detector CT (MDCT) and 80-row MDCT units were higher than the volume CT dose index (CTDIvol). The dose profile in the 320-row MDCT overlapped in two places but showed no overlap in the 80-row MDCT. There were no significant differences in image noise between the two scanning modes. The foetal dose evaluation by CTDIvol may underestimate the foetal radiation risk. When using the wide-volume mode, operators must take into account the number of scans and overlap between volumetric sections.


Subject(s)
Fetus/diagnostic imaging , Phantoms, Imaging , Tomography, Spiral Computed/methods , Body Burden , Female , Humans , Pregnancy , Radiation Dosage
9.
Article in English | MEDLINE | ID: mdl-19952054

ABSTRACT

Peripheral neurotoxicity is the major limiting factor for oxaliplatin therapy. Goshajinkigan (GJG), a traditional Japanese herbal medicine, was recently shown to be effective in protecting against the neurotoxicity of taxanes in Japan. We retrospectively investigated the effect of GJG on peripheral neurotoxicity associated with oxaliplatin therapy. Ninety patients with metastatic colorectal cancer that received FOLFOX4 or modified FOLFOX6 therapy were assigned to receive one of the following adjuncts: oral GJG at 7.5 g day(-1) (Group A, n = 11), intravenous supplementation of calcium gluconate and magnesium sulfate (1 g each before and after FOLFOX) (Group B, n = 14), combined GJG and calcium gluconate and magnesium sulfate therapies (Group C, n = 21), or no concomitant therapy (Group D, n = 44). The incidence of peripheral neurotoxicity was investigated when the cumulative dose of oxaliplatin exceeded 500 mg m(-2). When the cumulative dose of oxaliplatin exceeded 500 mg m(-2), the incidence of neuropathy (all grades) in Groups A-D was 50.0%, 100%, 78.9%, and 91.7%, respectively. It was lowest in the group that received GJG alone. Concomitant administration of GJG reduced the neurotoxicity of oxaliplatin in patients that received chemotherapy for colorectal cancer.

10.
Gan To Kagaku Ryoho ; 29(5): 757-60, 2002 May.
Article in Japanese | MEDLINE | ID: mdl-12040680

ABSTRACT

A 64-year-old-male had recurrent paraaortic lymph node and liver metastases eight months after total gastrectomy and with distal pancreatectomy and splenectomy for advanced gastric cancer. Combined chemotherapy with 5-FU and a low-dose of CDDP was effective and the both lesions disappeared. Thirteen months later, a second recurrence of anterior mediastinum lymph node metastases occurred. After the same protocol, the lesions showed a partial response and lymph node dissection was performed. Histopathological examination showed that the resected lymph nodes had 99% necrosis and fibrotic change. Immunohistochemical examination of p53 of the primary gastric cancer showed negative staining. The patient has been followed for three years after the operation, and has no recurrent lesions.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Gastrectomy , Liver Neoplasms/drug therapy , Liver Neoplasms/secondary , Lymph Nodes/pathology , Stomach Neoplasms/drug therapy , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Aorta/pathology , Cisplatin/administration & dosage , Drug Administration Schedule , Fluorouracil/administration & dosage , Humans , Lymph Node Excision , Lymphatic Metastasis , Male , Mediastinum/pathology , Middle Aged , Pancreatectomy , Splenectomy , Stomach Neoplasms/pathology , Stomach Neoplasms/surgery
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