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Yukimura Y.,Ikeda Municipal Hospital
Nihon Hoshasen Gijutsu Gakkai zasshi

In recent years, an applied successive approximation method has emerged as a new reconstruction technique of the computed tomography (CT). The CT unit of our hospital is equipped with an adaptive statistical iterative reconstruction (ASiR) which applies this method. This time, we have investigated the feature of the images through the ASiR. A subtraction of the filtered back projection (FBP) image from the ASiR image of various phantoms took place, and the structure marginal region was evaluated by varying the blend rate of ASiR and the display field of view (DFOV). By varying the CT value difference with the surroundings (using iodinated contrast medium) the structure marginal region of the subtraction image was evaluated. Modulation transfer function (MTF) and noise power spectrum (NPS) measurements were carried out to make evaluations. The result was that the CT value of the marginal unit structure was elevated with an increase of the blend ratio of ASiR and DFOV. When the CT value difference with surroundings was high, an edge was formed in the structure near the marginal region, and when it was low, a slowdown in the peripheral zone was observed. The value of MTF and NPS showed the change. The formation of the edge and slowdown in the peripheral zone can be seen in clinical images, we fully need to understand this result and make use of it in the clinical field. Source

Ohata C.,Ikeda Municipal Hospital | Nakai C.,Osaka Kosei Nenkin Hospital | Kasugai T.,Osaka Kosei Nenkin Hospital | Katayama I.,Osaka University
Journal of Cutaneous Pathology

Background: Consumption of the epidermis (hereafter, consumption), namely thinning of the epidermis with attenuation of basal and suprabasal layers and loss of rete ridges adjacent to collections of melanocytes, has been used to differentiate invasive melanoma from Spitz nevi. Evaluation of 213 invasive melanomas, including only two cases of acral lentiginous melanoma (ALM), showed that the frequency of consumption increases with increasing tumor thickness. Methods: We evaluated consumption in 52 acral melanomas relative to age, gender, Breslow depth, tumor thickness (based on the 2010 American Joint Commission on Cancer guidelines), Clark level, mitoses, ulceration, vertical-growth phase, regression, tumor-infiltrating lymphocytes and anatomical site. Results: Consumption was more frequent in ALM with increasing Breslow depth (p = 0.01), and in the presence of ulceration (p = 0.0078); in all cases with ulcer, consumption was found adjacent to the ulceration. There was no statistically significant difference in consumption in nail melanomas in comparison to melanomas of acral skin other than the nail. Conclusions: These results support the hypothesis that epidermal thinning in consumption represents an early phase of ulceration. No statistically significant difference in consumption was found between nail melanomas and melanomas of acral skin other than the nail, probably because of similar tumor thickness in both groups. Copyright © 2012 John Wiley & Sons A/S. Source

Kato M.,Osaka University | Nishida T.,Osaka University | Yamamoto K.,Toyonaka Municipal Hospital | Hayashi S.,Toyonaka Municipal Hospital | And 15 more authors.

Background: After endoscopic submucosal dissection (ESD) of early gastric cancer (EGC), patients are at high risk for synchronous or metachronous multiple gastric cancers. Objective: To elucidate the time at which multiple cancers develop and to determine whether scheduled endoscopic surveillance might control their development. Design: A multicentre retrospective cohort study from 12 hospitals was conducted. Patients with EGC who underwent ESD with en bloc margin-negative curative resection were included. Synchronous cancer was classified as concomitant cancer or missed cancer. The cumulative incidence of metachronous cancers and overall survival rate were calculated using the Kaplan-Meier method. Results: From April 1999 to December 2010, 1258 patients met the inclusion criteria. Synchronous or metachronous multiple cancers were detected in 175 patients (13.9%) during a mean of 26.8 months. Among the 110 synchronous cancers, 21 were missed at the time of the initial ESD. Many of the missed lesions existed in the upper third of the stomach and the miss rate was associated with the endoscopist's inexperience (<500 oesophagogastroduodenoscopy cases). The cumulative incidence of metachronous cancers increased linearly and the mean annual incidence rate was 3.5%. The incidence rate did not differ between patients with or without Helicobacter pylori eradication. Four lesions (0.32%) were detected as massively invading cancers during the follow-up. Conclusions: Nineteen per cent of synchronous cancers were not detected until the initial ESD. The incidence rate of metachronous cancer after ESD was constant. Scheduled endoscopic surveillance showed that almost all recurrent lesions were treatable by endoscopic resection. Source

There are several methods for measuring modulation transfer function (MTF) in computed tomography (CT) images. The aluminum slit method, scanning a phantom consisting of a thin aluminum foil sandwiched by flat plastic slabs, is a standard method for measuring field of view (FOV) in clinical CT scan. But this method requires extreme caution when handling metal foil of high precision. Therefore, we devised a more simple method named air gap slit (AS) method. This new technique is based on the aluminum slit method but use air gap instead of metal foil between phantoms. The MTF was calculated from a reversed profile curve of air slit which indicated minimum CT number. The aim of this study was to investigate a possibility of AS method evaluating MTF. We investigated fluctuation of MTF and FOV in clinical CT scan compared with the aluminum slit method. The result showed that the fluctuation of MTF was caused by statistics noise and is more affected by a bone kernel than standard kernel when reconstructing. Also, the MTF value in AS method was slightly higher than in aluminum slit method and did not correspond with. AS method is a useful method for measurement of MTF in clinical CT scan. When we use this method, we have to take into consideration the noise influence of data. Source

Mita T.,Juntendo University | Katakami N.,Osaka University | Shiraiwa T.,Shiraiwa Medical Clinic | Yoshii H.,Juntendo Tokyo Koto Geriatric Medical Center | And 13 more authors.
Diabetes Care

Objective The effect of additional treatment with oral hypoglycemic agents on the progression of atherosclerosis remains unknown in insulin-treated patients with type 2 diabetes mellitus (T2DM). We assessed the effects of sitagliptin, a dipeptidyl peptidase 4 inhibitor, on carotid intima-media thickness (IMT) in T2DM. Research Design and Methods This prospective, randomized, open-label, blinded end point, multicenter, parallelgroup, comparative study included 282 insulin-treated patients with T2DM free of a history of apparent cardiovascular diseases who were recruited at 12 clinical units and randomly allocated to either the sitagliptin group (n = 142) or the control group (n = 140). The primary outcomes were changes in mean and maximum IMT of the common carotid artery measured by echography at the end of a 104-week treatment period. Results Sitagliptin had a more potent glucose-lowering effect compared with the conventional treatment (20.5 ± 1.0% vs. 20.2 ± 0.9%; P = 0.004), without increasing hypoglycemic episodes or body weight. Changes in the mean and left maximum IMT, but not right maximum IMT, of the common carotid arteries were significantly greater after sitagliptin treatment compared with conventional treatment (20.029 [SE 0.013] vs. 0.024 [0.013] mm [P = 0.005]; 20.065 [0.027] vs. 0.022 [0.026] mm [P = 0.021]; 20.007 [0.031] vs. 0.027 [0.031] mm [P = 0.45], respectively). Over 104 weeks, sitagliptin, but not conventional treatment, significantly reduced the mean IMT and left maximumIMT of common carotid arteries relative to the baseline. Conclusions Sitagliptin attenuated the progression of carotid IMT in insulin-treated patients with T2DM free of apparent cardiovascular disease compared with conventional treatment. © 2016 by the American Diabetes Association. Source

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