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Passive needle guide tracking with radial acquisition and phase‐only cross‐correlation
Author(s) -
Reichert Andreas,
Reiss Simon,
Krafft Axel Joachim,
Bock Michael
Publication year - 2021
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.28448
Subject(s) - tracking (education) , correlation , cross correlation , phase (matter) , nuclear magnetic resonance , computer science , physics , mathematics , statistics , psychology , pedagogy , geometry , quantum mechanics
Purpose Acceleration of a passive tracking sequence based on phase‐only cross‐correlation (POCC) using radial undersampling. Methods The phase‐only cross‐correlation (POCC) algorithm allows passive tracking of interventional instruments in real‐time. In a POCC sequence, two cross‐sectional images of a needle guide with a positive MR contrast are continuously acquired from which the instrument trajectory is calculated. Conventional Cartesian imaging for tracking is very time consuming; here, a higher temporal resolution is achieved using a highly undersampled radial acquisition together with a modified POCC algorithm that incorporates the point‐spread‐function. Targeting and needle insertion is performed in two phantom experiments with 16 fiducial targets, each using 4 and 16 radial projections for passive tracking. Additionally, targeting of eight deep lying basivertebral veins in the lumbar spines is performed for in vivo proof‐of‐application with four radial projections for needle guide tracking. Results The radially undersampled POCC sequence yielded in the phantom experiments a lateral targeting accuracy of 1.1 ± 0.4 mm and 1.0 ± 0.5 mm for 16 and 4 radial projections, respectively, without any statistically significant difference. In the in vivo application, a mean targeting duration of 62 ± 13 s was measured. Conclusion Radial undersampling can drastically reduce the acquisition time for passive tracking in a POCC sequences for MR‐guided needle interventions without compromising the targeting accuracy.