Title
Joint deformable liver registration and bias field correction for MR-guided HDR brachytherapy.
Abstract
In interstitial high-dose rate brachytherapy, liver cancer is treated by internal radiation, requiring percutaneous placement of applicators within or close to the tumor. To maximize utility, the optimal applicator configuration is pre-planned on magnetic resonance images. The pre-planned configuration is then implemented via a magnetic resonance-guided intervention. Mapping the pre-planning information onto interventional data would reduce the radiologist's cognitive load during the intervention and could possibly minimize discrepancies between optimally pre-planned and actually placed applicators.We propose a fast and robust two-step registration framework suitable for interventional settings: first, we utilize a multi-resolution rigid registration to correct for differences in patient positioning (rotation and translation). Second, we employ a novel iterative approach alternating between bias field correction and Markov random field deformable registration in a multi-resolution framework to compensate for non-rigid movements of the liver, the tumors and the organs at risk. In contrast to existing pre-correction methods, our multi-resolution scheme can recover bias field artifacts of different extents at marginal computational costs.We compared our approach to deformable registration via B-splines, demons and the SyN method on 22 registration tasks from eleven patients. Results showed that our approach is more accurate than the contenders for liver as well as for tumor tissues. We yield average liver volume overlaps of 94.0 ± 2.7% and average surface-to-surface distances of 2.02 ± 0.87 mm and 3.55 ± 2.19 mm for liver and tumor tissue, respectively. The reported distances are close to (or even below) the slice spacing (2.5 - 3.0 mm) of our data. Our approach is also the fastest, taking 35.8 ± 12.8 s per task.The presented approach is sufficiently accurate to map information available from brachytherapy pre-planning onto interventional data. It is also reasonably fast, providing a starting point for computer-aidance during intervention.
Year
DOI
Venue
2017
10.1007/s11548-017-1633-2
Int. J. Computer Assisted Radiology and Surgery
Keywords
Field
DocType
Deformable registration,Bias field correction,Magnetic resonance imaging,Liver intervention,High-dose rate brachytherapy
Nuclear medicine,High-Dose Rate Brachytherapy,Internal radiation,Brachytherapy,Radiology,Medicine,Percutaneous,Bias field,Magnetic resonance imaging
Journal
Volume
Issue
ISSN
12
12
1861-6429
Citations 
PageRank 
References 
1
0.37
16
Authors
6
Name
Order
Citations
PageRank
Marko Rak1318.37
Tim König210.37
Klaus D. Tönnies321544.39
Mathias Walke410.71
Jens Ricke5209.47
Christian Wybranski610.37