In an article at the Globes [online], we read about TopSpin Medical from Israel, the developer of intra-vascular MRI (magnetic resonance imaging) catheter for coronary arteries.
This is how the company describes its interesting new technology:
TopSpin Medical has developed a self contained “inside-out” miniature MRI probe in a tip of an intravascular catheter that allows for local high-resolution imaging of blood vessels without the need for external magnets or coils. The advantages of this technique range from the very practical aspect of a low-cost system (since no expensive external setup is required), accessibility to the patient during the procedure, compatibility with existing interventional tools, and finally resolution and diffusion contrast capabilities that are unattainable by conventional clinical MRI, due to the strong local gradients created by the probe and its proximity to the examined tissue.
The intravascular probe serves as a first example for a wide range of applications for this method, which in the near future may the field of clinical MRI. It opens the door for the application of MRI in cases where high-resolution local images are required and when the transformation into an MRI environment is both mentally and economically difficult for the hospital. The medical applications for this technology include detection and staging of prostate cancer, imaging tumors in the colon, lung and breast and intravascular imaging of the peripheral vasculature…
A static magnetic field of about 0.2 Tesla is generated by strong permanent magnets located at the tip of the catheter. The gradients that result from such a small configuration are in the range of 100-300 T/m, and may be controlled to some extent by changing the angle of the magnetization and the dimensions of the gap between the two magnet pieces. Due to volume constraints, a single coil is used both for transmission and for reception. The magnetic field profile created by this “inside-out” probe within the imaged volume is significantly different from that created by conventional NMR or MRI setups.