Basic Study of Susceptibility-Weighted Imaging at 1.5T

With the aim of sequence optimization in susceptibility-weighted imaging (SWI), 2 image acquisition parameters (slice thickness and matrix size) and 2 image processing conditions (number of slices per minimum intensity projection (MIP) and Sliding Window) were investigated using a 1.5-T magnetic resonance imaging (MRI) system. The subjects were 12 healthy volunteers and the target region for scanning was the whole brain. Informed consent was obtained from all subjects. First, susceptibility-weighted images were acquired with various slice thicknesses from 1mm to 5mm and various matrix sizes from 256x256 to 512x512, and the images were assessed in terms of the contrast-to-noise ratio (CNR) and were also visually evaluated by three radiologists. Then, the number of slices per MIP and the usefulness of the Sliding Window were investigated. In the study of the optimal slice thickness and matrix size, the results of visual evaluation suggested that a slice thickness of 3mm and a matrix size of 448x448 are optimal, while the results of evaluation based on CNR were not significant. As regards the image processing conditions, the results suggested that the number of slices per MIP should be set to a minimum value of 2 and that the use of Sliding Window is effective. The present study provides useful reference data for optimizing SWI sequences.</p

The Diagnostic Capacity of Pre-treatment 18F-FDG PET/CT for Predicting the Extranodular Spread of Lymph Node Metastases in Patients with Oral Squamous Cell Carcinoma

The aim of this study was to evaluate the ability of pretreatment 90-min 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) to predict the extranodular spread of lymph node metastases in oral squamous cell carcinoma. We retrospectively reviewed the cases of 56 patients who underwent pretreatment 18F-FDG PET/CT and surgery with neck dissection. Maximum standardized uptake value, metabolic tumor volume, and total lesion glycolysis were measured for the 56 primary sites and maximum standardized uptake value was measured for 115 lymph node levels. Extranodular spread was present at 9 lymph node levels in 7 patients. Significant differences were found in metabolic tumor volume and total lesion glycolysis of the primary site, and in lymph node maximum standardized uptake value, between patients with and without extranodular spread (p<0.05). Combining primary site total lesion glycolysis and lymph node maximum standardized uptake volume at their respective optimal cutoffs, the sensitivity, specificity, and accuracy for predicting extranodular spread were 89%, 92%, and 92%, respectively. Pretreatment 18F-FDG PET/CT is useful for predicting extranodular spread in patients with oral squamous cell carcinoma. The combined use of primary site total lesion glycolysis and lymph node maximum standardized uptake value showed greater predictive value than either predictor singly

Physical Image Quality of Rapid Processing Films

The imaging properties of Konica "new" SR series films and "old" MG-SR series films for rapid processing were measured in combination with green-emitting intensifying screens. The measured image quality prarameters include: characteristic curve, modulation transfer function (MTF) and Wiener spectrum. The relative speeds of the new SR series systems were slower than those of the old MG-SR series systems from 10 to 25%. The MTF's of the new systems were generally comparable to those of the old systems, except that SR-G system was improved with an increase of approximately 10%. In the Wiener spectrum measurement, however, the new systems showed from 10 to 35% decrease in low-frequency noise

Clinical evaluation was examined between mixed type barium sulfate suspensions "BarytgenHD" and "Barytgen"

混合粒子型硫酸バリウムバリトゲンHD200w/v%懸濁液について,バリトゲン160w/v%懸濁液と比較検討を行った｡懸濁液安定性は両者共良かった｡臨床評価においては,付着性,胃小区描出能は同程度であり,辺縁の描出能は良かったが凝集･ムラ付き,気泡は多くみられ懸濁液濃度について検討を加える必要があると考える｡飲み易さは,バリトゲンHD200w/v%懸濁液のほうが濃度が高いのにもかかわらず飲み易く好評であった｡Both barium sulfate suspensions, Barytgen HD and Barytgen, had good stability. Although significant difference was not abserved in coating and visualization of gastric area, BarytgenHD showed better marginal visualization of gastric margin. Further study is needed to improve the visualization of sticky coating of gastric mucosa and many bubbles. BarytgenHD was easily to drink instead of high density barium sulfate suspensions

Clinical effectiveness of four neuraminidase inhibitors (oseltamivir, zanamivir, laninamivir, and peramivir) for children with influenza A and B in the 2014-2015 to 2016-2017 influenza seasons in Japan

The clinical effectiveness of four neuraminidase inhibitors (NAIs) (oseltamivir, zanamivir, laninamivir, and peramivir) for children aged 0 months to 18 years with influenza A and B were investigated in the 2014-2015 to 2016-2017 influenza seasons in Japan. A total of 1207 patients (747 with influenza A and 460 with influenza B) were enrolled. The Cox proportional-hazards model using all of the patients showed that the duration of fever after administration of the first dose of the NAI was shorter in older patients (hazard ratio = 1.06 per 1 year of age, p < 0.001) and that the duration of fever after administration of the first dose of the NAI was shorter in patients with influenza A infection than in patients with influenza B infection (hazard ratio = 2.21, p < 0.001). A logistic regression model showed that the number of biphasic fever episodes was 2.99-times greater for influenza B-infected patients than for influenza A-infected patients (p < 0.001). The number of biphasic fever episodes in influenza A-or B-infected patients aged 0-4 years was 2.89-times greater than that in patients aged 10-18 years (p = 0.010), and the number of episodes in influenza A-or B-infected patients aged 5-9 years was 2.13times greater than that in patients aged 10-18 years (p = 0.012)