SARS pneumonia can manifest as focal peripheral consolidation that clears relatively quickly and does not cause secondary complications or that progresses to bilateral consolidation and a more protracted clinical course.

New technological advancements including multislice CT scanners and functional MRI, have dramatically increased the size and number of digital images generated by medical imaging departments. Despite the fact that the cost of storage is dropping, the savings are largely surpassed by the increasing volume of data being generated. While local area network bandwidth within a hospital is adequate for timely access to imaging data, efficiently moving the data between institutions requires wide area network bandwidth, which has a limited availability at a national level. A solution to address those issues is the use of lossy compression as long as there is no loss of relevant information. The goal of this study was to determine levels at which lossy compression can be confidently used in diagnostic imaging applications. In order to provide a fair assessment of existing compression tools, we tested and compared the two most commonly adopted DISCOM compression algorithms: JPEG and JPEG-2000. We conducted an extensive pan-Canadian evaluation of lossy compression applied to seven anatomical areas and five modalities using two recognized techniques: objective methods or diagnostic accuracy and subjective assessment based on Just Noticeable Difference. By incorporating both diagnostic accuracy and subjective evaluation techniques, enabled us to define a range of compression for each modality and body part tested. The results of our study suggest that at low levels of compression, there was no significant difference between the performance of lossy JPEG and lossy JPEG 2000, and that they are both appropriate to use for reporting on medical images. At higher levels, lossy JPEG proved to be more effective than JPEG 2000 in some cases, mainly neuro CT. More evaluation is required to assess the effect of compression on thin slice CT. We provide a table of recommended compression ratios for each modality and anatomical area investigated, to be integrated in the Canadian Association of Radiologists standard for the use of lossy compression in medical imaging.

The possible beneficial or adverse effects of long-term diuretic use in the elderly were evaluated in 60 males (mean age 80.0 years) and 17 females (mean age 84.3 years). All subjects were found to have no obvious need for diuretics when initially assessed and were not receiving concurrent digoxin therapy. Residents were randomly allocated to placebo or active groups with stratification for prior hypertension or congestive heart failure (CHF) and they were followed for one year in a double-blind design. Mean BP, heart rate and weight at one year were similar to baseline values in both groups. Six active and two placebo subjects developed CHF and two other placebo subjects had a return of BP to hypertensive levels. Serum creatinine, cholesterol, potassium and BUN were significantly improved at one year in the placebo group. Chronic diuretic use did not alter appreciably the occurrence of CHF or hypertension in this elderly population and may not be necessary.

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