Format:
Online-Ressource
Content:
Abstract: Purpose: Acceleration of a passive tracking sequence based on phase-only cross-correlation (POCC) using radial undersampling.〈br〉〈br〉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.〈br〉〈br〉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.〈br〉〈br〉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.〈br〉〈br〉Keywords: MR-guided interventional procedures; MR-guided needle intervention; MR-guided prostate biopsy; interventional magnetic resonance imaging; interventional radiology
Note:
Magnetic resonance in medicine
,
85, 2 (2021) , 1039-1046, ISSN: 1522-2594
Language:
English
URN:
urn:nbn:de:bsz:25-freidok-1680263
URL:
https://doi.org/10.1002/mrm.28448
URL:
https://nbn-resolving.org/urn:nbn:de:bsz:25-freidok-1680263