Magnetresonanztomographie bei tragern kunstlicher herzklappen - 1998- Umfrage unter 25 klappenherstellern sowie vorstellung der gegenwartigen literatur uber sicherheitsaspekte

The indications for magnetic resonance imaging (MRI) on prosthetic heart valve recipients remain critical. A generalized contraindication for MRI is doubtful. Some diagnostic questions such as interests in pathologies of the posterior cranial fossa, spinal abscesses, and internal derangements for the knee, strongly recommend the advantages of MRI versus all other radiological diagnostic techniques. MRI can directly affect patients with prosthetic valves in three ways by: 1) movement or dislodgment of the prosthesis, 2) heating, and 3) arrhythmias induced by electric currents, and indirectly by distortion of the image and its subsequent misinterpretation. Present literature that concerns the safety considerations of current values appears to be incomplete. Therefore, a survey of twenty-five valve manufacturers with regard to compatibility, safety or contraindication for MRI on their respective prosthetic heart valves was performed in 1998. Those manufacturers who distribute most of the valves in Europe confirmed the safety of MRI. However, some gave their assurances based on inadequate data, or assigned all responsibility to the physician. Some companies did not give any assurance for MRI safety or failed to respond to our enquiry. Two valve manufacturers warned against performing MRI on certain prostheses. Based on our 1998 questionnaire, the technical issues, the clinical circumstances, the prerequisites and criteria for and the definition of safety standards for MRI on prosthetic heart valve recipients are presented in this paper.