Procedures such as Radiofrequency Ablation (RFA) and Transjugular Intrahepatic Portosystemic Shunt (TIPS) placement are minimally invasive image-guided alternatives to surgical procedures.
4D ultrasound (US) has great potential for these interventions,
as it provides real-time 3D imaging.
respiratory liver motion hampers adequate visualization of the target region.
Therefore we propose a method to compensate breathing motion using real-time 3D US registration.
Methods and materials
Our registration method consists of four basic steps: a) Point Selection,
c) Outliers Rejection,
and d) Computation of a rigid transformation using the inliers.
The block-matching uses a similarity metric to establish point correspondences between volumes.
The outlier rejection uses geometric consistency to remove erroneous matchings from the block-matching.
The rigid transformation is computed using singular value decomposition method.
Thirteen 4D US volume sequences were acquired from six healthy volunteers at 6 Hz from an iU22 Philips machine.
From the 4D US sequences,
seven pairs of frames were selected in a systematic way such that they are representative of the whole breathing cycle.
Reference standard (ground truth) registration was established using the standard Elastix registration toolkit .
The Elastix toolbox is intensity based medical image registration application.
The Elastix results were visually...
We proposed and evaluated 3D US to US registration approach for motion compensation of liver.
A mean error of 1.3 mm is achieved for 85 non-consecutive pairs of 3D ultrasound volumes acquired from 4D ultrasound sequences.
Additionally we demonstrate that,
a GPU implementation of our registration approach can be used in real-time.
Jyotirmoy Banerjee is working in Erasmus MC as a PhD Student in the STW-funded project (OTP 10482): of "4D ultrasound for improved image guidance in minimally invasive needle interventions: the interventional cockpit".
His works aims at replacing classical surgical interventions by minimally invasive alternatives and help improve patient care.
elastix: A toolbox for intensity-based medical image registration.