Infusino M. H., Layne Sara Shatford, Viole O’Neill Ynez. The Computerized Index of Medieval Medical Images (IMMI) : Challenges and solutions. In: Le médiéviste et l'ordinateur, N°26-27, Automne 1992 ...- printemps 1993 1992. Traitements informatiques et iconographie. pp. 11-13.
Dynamic PET images are usually reconstructed one-by-one by methods designed for static images. This approach is suboptimal because it makes no use of information in the temporal correlations of the ...signal. Optimally, one should instead consider the entire dynamic study as a single space-time signal to be reconstructed. Unfortunately, direct implementation of this approach leads to a very time-consuming computation. However, the authors show that, by appropriate transformation of the imaging equation, one can achieve this goal with less computations than ordinary filtered backprojection (FBP) in some cases. The required steps are as follows: transform the sinograms to a reduced Karhunen-Loeve (KL) domain, restore them using a Wiener-type filter, apply FBP to reconstruct only the significant KL-coefficient images, then invert the KL transform to obtain a high-quality dynamic image sequence. Actual PET data and computer simulations are used to evaluate the method.
Several studies showed that thrombolysis reduces ventricular arrhythmias and improves heart rate variability (HRV) in patients with acute myocardial infarction (AMI). Primary percutaneous coronary ...intervention (PCI) has recently become the treatment of choice for AMI, but it is still unknown whether it has favorable effects on these prognostic variables.
We studied a group of 44 consecutive AMI patients (39 males, 5 females, mean age 59 +/- 9 years) submitted to primary PCI and 93 consecutive AMI patients (80 males, 13 females, mean age 61.0 +/- 11 years) treated with thrombolytic therapy within 6 hours of symptom onset. All patients underwent 24-hour Holter recording before discharge.
The number of premature ventricular beats and the prevalence of non-sustained ventricular tachycardia in the 24 hours were lower in the PCI group (162 +/- 474 and 9%, respectively) than in the thrombolysed group (334 +/- 1730 and 14%, respectively), but the difference did not achieve statistical significance (p = 0.62 and p = 0.58, respectively). There were also no significant differences in HRV variables between the two groups, although a lower proportion of PCI patients tended to have bottom quartile values of HRV variables. The favorable trend for arrhythmias and HRV in PCI patients, however, seemed to be related to a worse basal clinical profile of thrombolysed patients, including a higher prevalence of previous AMI (14 vs 2%, p = 0.065), diabetes (27 vs 18%, p = 0.14) and, in particular, a lower use of beta-blockers (35 vs 93%, p < 0.001).
In this study, we failed to show any significant benefit of primary PCI compared to thrombolysis on ventricular arrhythmias and HRV in patients with ST-segment elevation AMI. The clinical implications of these findings deserve investigation in future studies.
Cognitive psychology in the Middle Ages Infusino, Mark; Kemp, Simon
Journal of the history of the behavioral sciences,
07/1998, Volume:
XXXIV, Issue:
3
Book Review
Business reinvention means more than doing things better, or even doing them differently. It means radically changing the rules by which an industry operates. In reinventing its business, Fidelity ...has created a multichannel approach to broaden customer reach. In the financial services industry the best examples of growth are generally nonbanks, such as Advanta, T. Rowe Price, EDS, and GE Capital. These companies have been developing and offering new types of products and reaching new segments of customers in ways not foreseen by traditional banking. Business reinvention is a fundamental reshaping of relationships, both within an organization and between institutions. Like reengineering, it focuses on a product, processes, and customers, but then it goes beyond reengineering to reevaluate and redistribute roles among all value chain participants.
Typically, financial services firms have not connected IT projects to customer priorities or to the P&L statement. Assumptions about customer adoption or purchase rates for new capabilities or ...products tend to be rooted in hope rather than fact. For example, a telecommunications company intended to invest large sums to support an online service and ordering system for its business customers. When we conducted a quick survey, we found that only 9% of this company's business customers were "digital ready" to use the ordering capabilities being developed. Connect the dots. Determining how well your IT portfolio fits with your business objectives will allow you to make some rapid decisions for improvement. What customer adoption rates are required to reap the expected benefits? How do projects link to revenue and cost lines in the P&L? By making these connections, it is often possible to eliminate or redirect 20% or more of IT projects in a matter of weeks. And since many companies do not have this information readily available, the exercise can prompt both business and IT managers to evaluate their projects more rigorously.
Both exercise testing and C-reactive protein (CRP) serum levels have been shown to predict clinical events in patients with unstable angina. However, no previous study carefully compared their ...relative prognostic value in this clinical setting.
We reviewed data of 96 consecutive patients with unstable angina (77 males, 19 females, mean age 63.1 +/- 9.5 years), who were free from clinical events during hospital stay. A symptom/sign-limited treadmill exercise test had been performed and CRP serum levels had been measured prior to discharge in all patients.
During an average follow-up of 2.5 years (range 0.5-5 years), there were 8 major cardiac events (death or myocardial infarction) and 11 patients had recurrent unstable angina. Both exercise-induced myocardial ischemia relative risk (RR) 3.02, 95% confidence interval (CI) 0.58-15.5, p = 0.29, and CRP levels > or = 10 mg/l (RR 2.4, 95% CI 0.51-11.2, p = 0.25) showed a non significant association with major cardiac events. Low workload ischemia, however, was significantly associated with major cardiac events (RR 8.58, 95% CI 1.66-44.2, p = 0.01) and was also the only predictive variable for the combined endpoint of major events and recurrent angina (RR 2.57, 95% CI 1.02-4.44, p = 0.045). Among patients with low workload ischemia, the occurrence of major events was higher in those with high, compared to those with low, CRP levels, but the difference was not significant (28.6 vs 15.4%, p = 0.64).
In this study, pre-discharge myocardial ischemia at low workload was the single most important predictor of major cardiac events during long-term follow-up among patients with stabilized unstable angina. Increased serum CRP levels did not add further significant prognostic information in this specific group of patients with unstable angina, although this issue needs to be addressed in larger studies.
