Is magnetic resonance imaging (MRI) feasible with an indwelling transpulmonary thermodilution catheter: data from an observational analysis and from a survey

Magnetic resonance imaging (MRI) has become a widespread procedure in critical care patients. Some of these patients are equipped with implanted cardiovascular diagnostic or therapeutic devices. The main risks during MRI are movement due to magnetic attraction and burns. The risks depend on quality and quantity of the implanted conductive metallic material as well as on the strength of the magnetic field. There is confusion which patients with which devices can safely undergo MRI. This also applies to transpulmonary thermodilution (TPTD) catheters which currently are not approved to be left in place during MRI. However, risks of delaying MRI until the catheter can be removed, potential harms of removal and risks and costs of repeated arterial cannulation have to be outweighed.


Introduction
Magnetic resonance imaging (MRI) has become a widespread procedure in critical care patients. Some of these patients are equipped with implanted cardiovascular diagnostic or therapeutic devices. The main risks during MRI are movement due to magnetic attraction and burns. The risks depend on quality and quantity of the implanted conductive metallic material as well as on the strength of the magnetic field. There is confusion which patients with which devices can safely undergo MRI. This also applies to transpulmonary thermodilution (TPTD) catheters which currently are not approved to be left in place during MRI. However, risks of delaying MRI until the catheter can be removed, potential harms of removal and risks and costs of repeated arterial cannulation have to be outweighed.

Objectives
We analyzed a prospectively maintained TPTD database for patients undergoing MRI with PiCCO-TPTD (Pulsiocath; Pulsion Medical Systems SE, Germany) catheters left in place.

Methods
Patients charts of 16 patients undergoing 20 MRIs with TPTD-catheters were analyzed for side effects. To detect potential catheter dysfunction we compared the last measurements before and after MRI (Wilcoxon-test for paired samples; IBM SPSS 22). Furthermore, a questionnaire regarding the local standard procedure in case of MRI in patients with PiCCO-catheter was sent to 11 experts in hemodynamic monitoring.

Conclusions
1.) Despite the limitations of a small number of examinations our data do not give hints for harms to the patients 1 Klinikum rechts der Isar, II. Medizinische Klinik, Munich, Germany Full list of author information is available at the end of the article or to the TPTD catheter when leaving the TPTD catheter in situ during MRI.
2.) Limited residual risks of the indwelling catheter have to be outweighed to the risks of delayed examination or removal of the catheter and repeated cannulation as well as to the costs of repeated TPTD-catheter Insertion.