Electron spin resonance (ESR) probe for interventional MRI instrument localization

Abstract

This article presents a miniaturized electron spin resonance (ESR) probe for deducing the position of a surgical instrument on an MR image. The ESR probe constructed was small enough to fit inside a 14-G biopsy needle sheath, and position information of the sheath could be acquired using a simple gradient sequence. The position accuracy was estimated from needle trajectories as inferred from the needle artifact, the actual physical trajectory, and measured coordinates. The probe was able to track the tip of a biopsy needle quickly (10 samples/sec) and precisely with accuracy better than Ϯ2 mm.

MR-guided interventional procedures: a review

“…With this method, a current is applied through a wire built into the wall of the instrument causing field inhomogeneity and thus a signal void. There are also other potential methods for active instrument tracking, such as using electron spin resonance (ESR) (16) or inducing a signal from the instrument tip from an external source (42).…”