Sunnybrook Health Sciences Centre

About: Sunnybrook Health Sciences Centre is a healthcare organization based out in Toronto, Ontario, Canada. It is known for research contribution in the topics: Population & Medicine. The organization has 7689 authors who have published 15236 publications receiving 523019 citations. The organization is also known as: Sunnybrook.

Digital radiology using active matrix readout of amorphous selenium: construction and evaluation of a prototype real-time detector.

Abstract: The goal of the present work is to develop a large area, flat-panel solid-state detector for both digital radiography and fluoroscopy The proposed detector employs a photoconductive layer of amorphous selenium (a-Se) to convert x rays into charge The charge image formed by the a-Se layer is electronically read out in situ using a two dimensional array of thin film transistors (TFTs), or active matrix Since the active matrix readout is capable of producing x-ray images in real-time, it can potentially be applied in both radiography and fluoroscopy In this paper, the imaging performance of this concept is investigated using a prototype x-ray imaging detector The designs for the active matrix, the peripheral electronic circuits, and the image acquisition system are described Measurements of x-ray imaging properties of the prototype detector, ie, x-ray sensitivity, presampling modulation transfer function (MTF), and noise power spectrum (NPS), were performed, and from which the spatial frequency dependent detective quantum efficiency (DQE) of the prototype was derived The experimental results are in agreement with the results of our theoretical analysis The factors affecting the imaging performance and methods of improvement in the future are discussed

Characterization of lead zirconate titanate ceramics for use in miniature high-frequency (20-80 MHz) transducers

Abstract: The material properties of lead zirconate titanate (PZT) ceramics for operation in the thickness mode at frequencies as high as 80 MHz are reported. Each of the ceramics tested showed a reduction in k/sub t/ with increasing frequency. In a fine-grained PZT, values of k/sub t/ as high as 0.44 were measured at 80 MHz. The effects of grain size were also evident in the measurement of frequency dependent mechanical losses. Experimental and theoretical analysis of a 1 mm*1 mm, 45 MHz PZT transducer verified the validity of the measurements of the properties and demonstrated excellent insertion loss and bandwidth characteristics. The minimum insertion loss of -17.5 dB is in good agreement with theory and is a marked improvement over the performance of polymer devices. Details on the fabrication and testing of high frequency ceramic transducers are described. >

Uncertainty, symptom distress, and information needs after surgery for cancer of the colon

Abstract: The purpose of this study was to determine the relationships between uncertainty, symptom distress, and discharge information needs in individuals after a colon resection for cancer. The theoretical framework for the study was derived from Lazarus and Folkman's stress, appraisal, and coping model, and Mishel's theory of uncertainty in illness. Uncertainty was measured by the Mishel Uncertainty Illness Scale (MUIS); symptom distress of pain, fatigue, constipation, diarrhea and loss of appetite by visual analogue scales; and discharge information needs by the Patient Learning Need Scale (PLNS). Forty individuals with a first diagnosis of cancer were interviewed after surgical resection of colon cancer. The study results indicated that they had moderate levels of uncertainty, low levels of symptom distress, and a moderate number of discharge information needs. Information related to treatment, complications, and activities of living were identified as highly important. An increase in uncertainty was significantly associated with an increase in discharge information needs. Increased attention to information needs at discharge may decrease an individual's level of uncertainty and facilitate the transition from hospital to home.

Meta-analysis: Effects of Percutaneous Coronary Intervention Versus Medical Therapy on Angina Relief

Abstract: In this meta-analysis of angina relief with percutaneous coronary intervention (PCI) versus medical therapy in patients with coronary artery disease, pooled data from 14 randomized trials 1 to 7 ye...