The new RV analysis software allowed validation of the accuracy of 4D echo RV volume data compared with MRI.

Purpose:To determine the mechanism of enhancement of contrast-enhanced MRI (ceMRI) in chronic ischemic myocardium. While ceMRI can identify scar tissue in chronic ischemic myocardium, the mechanism of enhancement is not completely understood. Materials and Methods:A total of 11 patients with ischemic heart failure (ejection fraction [EF] 28 Ϯ 9%) were imaged with ceMRI and positron emission tomography (PET) to measure myocardial blood flow (MBF). Longitudinal relaxation rate (T1) of blood, normal tissue, and scar tissue defined by ceMRI was determined before and two to 50 minutes after contrast (Look Locker technique), and the partition coefficient () and volume of distribution (VD) were calculated. Results:In scar and viable tissue, T1 was significantly different over the whole period after contrast, but not before contrast. However, T1 of scar and blood were similar five to 15 minutes post contrast, making the detection of subendocardial defects difficult. reached an initial steady state in viable tissue, but was delayed (20 minutes) in scar tissue. VD in scar was double that of viable tissue (0.54 Ϯ 0.01 vs. 0.29 Ϯ 0.02, respectively) indicating an increased interstitial space. Contrast wash-in kinetics correlated moderately with MBF (r ϭ -0.36), but well with the combination of MBF and VD (r ϭ 0.59). Conclusion:Late myocardial contrast kinetics depend on both MBF and VD; however the increased VD seems to be the main mechanism for the late enhancement effect.

Three-dimensional echocardiography combined to semi-automated quantification software shows fair agreement with MRI for RV volumes and EF measurement in patients with repaired ToF and adequate intra- and interobserver variability. These results suggest applicability for serial follow-up of patients with right heart congenital disease. However, the accuracy of 3DE echo diminishes with larger RV volumes, in part due to current difficulty to include the entire RV in the imaged sector. Technical progress in transducers beam geometry is likely to address this issue.

Telemedical information systems (TIS's) form the basis for telemedicine services as well as for health information services. This paper gives an introduction to the wide scope of TIS's and discusses examples for the different types of TIS's: patient-related TIS's, knowledge-related TIS's, and meta-TIS's. It concludes that for patient-related TIS's there is the need for a better integration of TIS's with other patient-centered information systems. For the other types of TIS's, more sophisticated retrieval techniques and better user interfaces for ordinary users are required. Furthermore, short descriptions of our own projects are given: the patient-related TIS of the project TECSAC (distributed electronic patient record for cardiology) and the domain-specific knowledge-related TIS's ODITEB (radiological Internet text-book) and ENDOTEL-EIS (endoscopy information system).

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