Background and aims
Interventional magnetic particle imaging (MPI) allows for endovascular procedures guided via radiation-free visualization of tracers without background signal. The first human-sized MPI scanner dedicated for vascular intervention on extremities (iMPI scanner) shows promising results in phantoms. The aim of this study was to demonstrate its capabilities in a more realistic model of an extracoporeally perfused human cadaveric upper leg.
Methods
After surgical preparation of inguinal and popliteal vascular access, a peristaltic pump was used to establish extracorporeal perfusion in one human cadaver. In our angiography lab, the iMPI scanner and suitable receive coils were placed around the upper leg within the X-ray unit. A mixture of tracer (Ferucarbotran, Resotran) and contrast dye (Imeron 350) was injected under continuous perfusion and imaged simultaneously with MPI and DSA. Tracer passage was assessed qualitatively and quantitatively.
Results
The extracorporeally perfused human cadaveric model realistically depicted vascular interventions in the living. The iMPI scanner and its peripheral components could be integrated in the angiography lab. Simultaneous imaging with DSA and MPI was feasible. In a shared field of view of 12 x 8 cm the iMPI scanner realized a spatial resolution of about 5 mm and a temporal resolution of up to 10 frames per second (versus 2 fps for DSA) with accurate delineation of bolus influx and clearance. The injection of a bolus of 1 vial Resotran (1.6 ml) yielded a SNR of 10.
Conclusion
This is the first study to demonstrate that the human-sized iMPI scanner intended for use in vascular interventions can be utilized for guidance of endovascular procedures in the superficial femoral artery with a tracer approved for use in humans.
Author
Dr
Julius Maximilian University of Wurzburg