Automatic slice positioning (ASP) for passive real-time tracking of interventional devices using projection-reconstruction imaging with echo-dephasing (PRIDE)

S. Patil, O. Bieri, P. Jhooti, K. Scheffler

Research output: Contribution to journalArticlepeer-review

Abstract

A novel and fast approach for passive real-time tracking of interventional devices using paramagnetic markers, termed "projection-reconstruction imaging with echo-dephasing" (PRIDE) is presented. PRIDE is based on the acquisition of echo-dephased projections along all three physical axes. Dephasing is preferably set to 4π within each projection ensuring that background tissues do not contribute to signal formation and thus appear heavily suppressed. However, within the close vicinity of the paramagnetic marker, local gradient fields compensate for the intrinsic dephasing to form an echo. Successful localization of the paramagnetic marker with PRIDE is demonstrated in vitro and in vivo in the presence of different types of off-resonance (air/tissue interfaces, main magnetic field inhomogeneities, etc). In order to utilize the PRIDE sequence for vascular interventional applications, it was interleaved with balanced steady-state free precession (bSSFP) to provide positional updates to the imaged slice using a dedicated real-time feedback link. Active slice positioning (ASP) with PRIDE is demonstrated in vitro, requiring approximately 20 ms for the positional update to the imaging sequence, comparable to existing active tracking methods.

Original languageEnglish (US)
Pages (from-to)935-942
Number of pages8
JournalMagnetic resonance in medicine
Volume62
Issue number4
DOIs
StatePublished - Oct 2009
Externally publishedYes

Keywords

  • Automatic slice positioning
  • Echo-dephasing
  • Interventional MRI
  • Passive tracking
  • Susceptibility

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

Fingerprint

Dive into the research topics of 'Automatic slice positioning (ASP) for passive real-time tracking of interventional devices using projection-reconstruction imaging with echo-dephasing (PRIDE)'. Together they form a unique fingerprint.

Cite this