MR fluoroscopy in vascular and cardiac interventions (review)

Vascular and cardiac disease remains a leading cause of morbidity and mortality in developed and emerging countries. Vascular and cardiac interventions require extensive fluoroscopic guidance to navigate endovascular catheters. X-ray fluoroscopy is considered the current modality for real time imaging. It provides excellent spatial and temporal resolution, but is limited by exposure of patients and staff to ionizing radiation, poor soft tissue characterization and lack of quantitative physiologic information. MR fluoroscopy has been introduced with substantial progress during the last decade. Clinical and experimental studies performed under MR fluoroscopy have indicated the suitability of this modality for: delivery of ASD closure, aortic valves, and endovascular stents (aortic, carotid, iliac, renal arteries, inferior vena cava). It aids in performing ablation, creation of hepatic shunts and local delivery of therapies. Development of more MR compatible equipment and devices will widen the applications of MR-guided procedures. At post-intervention, MR imaging aids in assessing the efficacy of therapies, success of interventions. It also provides information on vascular flow and cardiac morphology, function, perfusion and viability. MR fluoroscopy has the potential to form the basis for minimally invasive image–guided surgeries that offer improved patient management and cost effectiveness

[MRI of the knee joint: first results of a comparison of 0,2-T specialized system and 1,5-T high field strength magnet]

PURPOSE: Diagnostic accuracy and image quality of a specialised system for MR examinations of peripheral joints were evaluated. MATERIALS AND METHODS: 20 patients with acute or chronic injuries of the knee were examined using a low-field MR system (0.2 T). For comparison, all patients were also studied with a 1.5 T high field strength magnet and all diagnoses were correlated with arthroscopic findings. RESULTS: We found compatible diagnostic accuracies (cruciate ligaments 90%, menisci 75-90%) and good image quality ratings for the low field system ("good" and "excellent" image quality in 83% of cases). CONCLUSION: The low-field MR-system offers low-cost MR examinations of peripheral joints with good image quality and reliable diagnostic information

MRI of peripheral joints with a low-field dedicated system: a reliable and cost-effective alternative to high-field units?

In the age of health care cost containment new imaging technology has to meet diagnostic requirements as well as economic limitations. In the MR sector new dedicated systems promise reliable diagnostic information at considerably lower costs than whole-body imagers. Within the past 18 months we have examined 2200 patients with acute and chronic lesions of peripheral joints (knee, ankle, foot, elbow, wrist, hand) in a 0.2T dedicated MR system (ARTOSCAN, Esaote Biomedica, Genoa, Italy). We report our experience with this system focusing on its special features, cost-effectiveness and on diagnostic accuracy of low-field MR studies of the knee in correlation with arthroscopy and in comparison with high-field whole-body imagers