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Maximum Enhancement (maximum + enhancement)
Selected AbstractsDynamic MRI, dynamic multidetector-row computed tomography (MDCT), and coregistered 2-[fluorine-18]-fluoro-2-deoxy-D-glucose,positron emission tomography (FDG-PET)/CT: Comparative study of capability for management of pulmonary nodulesJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 6 2008Yoshiharu Ohno MD Abstract Purpose To compare the nodule management capabilities of dynamic MRI, dynamic multidetector-row computed tomography (MDCT) and coregistered positron emission tomography (PET)/CT. Materials and Methods Dynamic MRI, dynamic MDCT, PET, microbacterial, and pathological examinations were administered to 175 consecutive patients with 202 nodules (<30 mm in diameter). The final diagnoses resulted in the classification of 202 nodules into two groups: requiring further intervention and treatment (N = 163) and no further evaluation (N = 39) groups. Maximum relative enhancement and slope of enhancement ratio were calculated as dynamic MR indices. Maximum enhancement, net enhancement, slope of enhancement, and absolute loss of enhancement were calculated as dynamic CT indices. maximum value of standard uptake value (SUVmax) was measured on coregistered PET/CT. Receiver operating characteristics (ROC) analyses were performed to determine feasible threshold values for nodule management, and results were tested using McNemar's test. Results When feasibility threshold values were adopted for nodule management, the specificity (82.1%) and accuracy (93.6%) of the slope of the enhancement ratio were significantly higher than those of dynamic CT indices (P < 0.05) and SUVmax (P < 0.05). Conclusion Dynamic MRI can play a more specific and/or accurate role for nodule management as compared with dynamic MDCT and coregistered PET/CT. J. Magn. Reson. Imaging 2008;27:1284,1295. © 2008 Wiley-Liss, Inc. [source] Fluid flow and heat transfer characteristics of cone orifice jet (effects of cone angle)HEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 4 2009Mizuki Kito Abstract The use of a jet from an orifice nozzle with a saddle-backed-shape velocity profile and a contracted flow at the nozzle exit may improve the heat transfer characteristics on an impingement plate because of its larger centerline velocity. However, it requires more power to operate than a common nozzle because of its higher flow resistance. We therefore initially considered the use of a cone orifice nozzle to obtain better heat transfer performance as well as to decrease the flow resistance. We examined the effects of the cone angle , on the cone orifice free jet flow and heat transfer characteristics of the impinging jet. We compared two nozzles: a pipe nozzle and a quadrant nozzle. The first one provides a velocity profile of a fully developed turbulent pipe flow, and the second has a uniform velocity profile at the nozzle exit. We observed a significant enhancement of the heat transfer characteristics of the cone orifice jets at Re=1.5×104. Using the cone orifice impinging jets enhanced the heat transfer rates as compared to the quadrant jet, even when the jets were supplied with the same operational power as the pipe jet. For instance, a maximum enhancement up to approximately 22% at r/do,0.5 is observed for ,=15°. In addition, an increase of approximately 7% is attained as compared to when the pipe jet was used. © 2009 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20243 [source] Inverse Opal Structure of Nitrogen-Doped Titanium Oxide with Enhanced Visible-Light Photocatalytic ActivityJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 2 2008Qi Li Nitrogen-doped titanium oxide inverse opal structure was synthesized to combine both chemical and physical modifications on n -TiO2 by the polystyrene sphere self-assembly followed by a sol,gel process. Enhanced visible-light absorption and subsequently enhanced photodegradation efficiency were observed in this unique structure, which can be attributed to both nitrogen-doping effect and inverse opal structure effect. Our work suggests that the coupling of photonic band gap structure with photocatalytic materials is a promising approach to achieve maximum enhancement for various photocatalytic materials, especially for environmental applications and solar cell devices. [source] Textural analysis of contrast-enhanced MR images of the breastMAGNETIC RESONANCE IN MEDICINE, Issue 1 2003Peter Gibbs Abstract Texture analysis was applied to high-resolution, contrast-enhanced (CE) images of the breast to provide a method of lesion discrimination. Significant differences were seen between benign and malignant lesions for a number of textural features, including entropy and sum entropy. Using logistic regression analysis (LRA), a diagnostic accuracy of Az = 0.80 ± 0.07 was obtained with a model requiring only three parameters. By initially dividing the patient data into training and test datasets, reasonable model robustness was also established. On combining features obtained using textural analysis with lesion size, time to maximum enhancement, and patient age, a diagnostic accuracy of Az = 0.92 ± 0.05 was demonstrated. Magn Reson Med 50:92,98, 2003. © 2003 Wiley-Liss, Inc. [source] Effect of molecular weight and end capping on poly(lactic- co -glycolic acid) ultrasound contrast agentsPOLYMER ENGINEERING & SCIENCE, Issue 9 2008J.R. Eisenbrey Ultrasound contrast agents (CA) consist of stabilized gas bubbles that, when injected intravenously, provide an acoustic impedance mismatch, producing additional contrast to a diagnostic ultrasound scan. These agents must be smaller than 8 ,m in order to pass safely through the capillaries, contain gas for an impedance mismatch and should be stable enough to survive the duration of the imaging session. A double emulsion technique has previously been optimized within our laboratory to create CA with 50:50 poly (lactic- co -glycolic acid) (PLGA). Although a great deal of research has focused on the effects of molecular weight and end capping on solid PLGA particles, very little has been done to examine the effects of these parameters on hollow CAs formed in a double emulsion. Non-end capped PLGA was found to provide maximum enhancement at a molecular weight of 66.0 kDa, giving an ultrasound enhancement of roughly 18.5 dB. The enhancement demonstrated by CA formed using the end-capped PLGA rose to a maximum enhancement of 19 dB at the highest commercially available molecular weight of 82.4 kDa. A strong correlation was seen between ultrasound enhancement, stability under ultrasonic conditions, surface morphology and zeta potential. This study shows the influence of polymer characteristics on the resulting properties of CA and the ability to tailor CAs to particular applications by varying the polymer choice. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers [source] | |||||||||||||