Automatic 3D ultrasound calibration for image guided therapy using intramodality image registration

Abstract

Many real time ultrasound (US) guided therapies can benefit from management of motion-induced anatomical changes with respect to a previously acquired computerized anatomy model. Spatial calibration is a prerequisite to transforming US image information to the reference frame of the anatomy model. We present a new method for calibrating 3D US volumes using intramodality image registration, derived from the “hand eye” calibration technique. The method is fully automated by implementing data rejection based on sensor displacements, automatic registration over overlapping image regions, and a self-consistency error metric evaluated continuously during calibration. We also present a novel method for validating US calibrations based on measurement of physical phantom displacements within US images. Both calibration and validation can be performed on arbitrary phantoms. Results indicate that normalized mutual information and localized cross correlation produce the most accurate 3D US registrations for calibration. Volumetric image alignment is more accurate and reproducible than point selection for validating the calibrations, yielding <1.5 mm root mean square error, a significant improvement relative to previously reported hand eye US calibration results. Comparison of two different phantoms for calibration and for validation revealed significant differences for validation (p=0.003) but not for calibration (p=0.795).

Early prediction of tumor response to bevacizumab treatment in murine colon cancer models using three-dimensional dynamic contrast-enhanced ultrasound imaging

“…FDA-approved perflutren microbubbles (Definity; Lantheus Medical Imaging, Inc., North Billerica, MA) were used (diluted 1:4 in sterile 0.9% saline solution after activation) and a 120-μL suspension was administered within a 5-second bolus (at a constant injection rate of 24 μl/sec) by using the infusion pump. Three-dimensional DCE-US datasets were acquired in real time continuously for four minutes in each mouse through a built-in Digital Navigation Link connecting the ultrasound system directly to custom in-house MevisLab modules (MeVis Medical Solutions AG, Bremen, Germany) written in C++ [20]. …”

VEGFR2-Targeted Three-Dimensional Ultrasound Imaging Can Predict Responses to Antiangiogenic Therapy in Preclinical Models of Colon Cancer

“…Sixty seconds after microbubble destruction (the time needed to fully replenish the tumor vessels within the tumor volume in the animal models used, according to our experience), imaging signal was measured a second time and the 3DUSMI imaging signal intensity from molecularly bound MB VEGFR2 was quantified as the difference in imaging signals before and after the high-power ultrasound pulses as described (17,24,25). The entire 3DUSMI imaging sequence was recorded in real time by using a built-in Digital Navigation Link of the ultrasound system with custom in-house MevisLab modules written in C++ (26). …”

Hand-eye calibration of a robot - UltraSound probe system without any 3D localizers

“…[1], [11] and [4] respectively found a RMS targeting point error of 3.5mm by using 12 2D images, 2.37mm with 56 US volumes and 2.0mm with 36 US volumes. These hand-eye methods use accurate 3D localizers to obtain B i matrices and registration tools to obtain A i matrices.…”

“…As a consequence, the hand-eye calibration problem cannot be solved with a high number of positions to have a robust X matrix. Rejection criteria algorithms could so be implemented to eliminate acquisitions considered as outliers due to a bad registration [4] or induced by a noise in the robot.…”

“…To overcome this shortcoming the literature mainly presents two types of calibration techniques using external 3D localizers [1]. In these techniques, a tracking reference frame is fixed on the probe and US volumes are acquired from a tracked phantom immersed in a water bath, as it explained in [1], [2] and [3], or by directly registering US volumes [4].…”