Journal article
Calibration of three-dimensional ultrasound images for image-guided radiation therapy
Physics in medicine & biology, Vol.46(2), pp.559-577
2001
DOI: 10.1088/0031-9155/46/2/321
PMID: 11229734
Abstract
A new technique of patient positioning for radiotherapy/radiosurgery of extracranial tumours using three-dimensional (3D) ultrasound images has been developed. The ultrasound probe position is tracked within the treatment room via infrared light emitting diodes (IRLEDs) attached to the probe. In order to retrieve the corresponding room position of the ultrasound image, we developed an initial ultrasound probe calibration technique for both 2D and 3D ultrasound systems. This technique is based on knowledge of points in both room and image coordinates.
We first tested the performance of three algorithms in retrieving geometrical transformations using synthetic data with different noise levels. Closed form solution algorithms (singular value decomposition and Horn's quaternion algorithms) were shown to outperform the Hooke and Jeeves iterative algorithm in both speed and accuracy. Furthermore, these simulations show that for a random noise level of 2.5, 5, 7.5 and 10 mm, the number of points required for a transformation accuracy better than 1 mm is 25, 100, 200 and 500 points respectively. Finally, we verified the tracking accuracy of this system using a specially designed ultrasound phantom.
Since ultrasound images have a high noise level, we designed an ultrasound phantom that provides a large number of points for the calibration. This tissue equivalent phantom is made of nylon wires, and its room position is optically tracked using IRLEDs. By obtaining multiple images through the nylon wires, the calibration technique uses an average of 300 points for 3D ultrasound volumes and 200 for 2D ultrasound images, and its stability is very good for both rotation (standard deviation: 0.4°) and translation (standard deviation: 0.3 mm) transformations. After this initial calibration procedure, the position of any voxel in the ultrasound image volume can be determined in world space, thereby allowing real-time image guidance of therapeutic procedures. Finally, the overall tracking accuracy of our 3D ultrasound image-guided positioning system was measured to be on average 0.2 mm, 0.9 mm and 0.6 mm for the AP, lateral and axial directions respectively.
Details
- Title: Subtitle
- Calibration of three-dimensional ultrasound images for image-guided radiation therapy
- Creators
- Lionel G BOUCHET - Department of Neurological Surgery, University of Florida, Gainesville, FL, United StatesSanford L MEEKS - Division of Radiation Oncology, University of Iowa, Iowa City, IA, United StatesGordon GOODCHILD - Medtronie Surgical Navigation Technologies, Broomfield, CO, United StatesFrancis J BOVA - Department of Neurological Surgery, University of Florida, Gainesville, FL, United StatesJohn M BUATTI - Division of Radiation Oncology, University of Iowa, Iowa City, IA, United StatesWilliam A FRIEDMAN - Department of Neurological Surgery, University of Florida, Gainesville, FL, United States
- Resource Type
- Journal article
- Publication Details
- Physics in medicine & biology, Vol.46(2), pp.559-577
- Publisher
- Institute of Physics; Bristol
- DOI
- 10.1088/0031-9155/46/2/321
- PMID
- 11229734
- ISSN
- 0031-9155
- eISSN
- 1361-6560
- Language
- English
- Date published
- 2001
- Academic Unit
- Radiation Oncology; Neurosurgery; Otolaryngology
- Record Identifier
- 9984040496302771
Metrics
22 Record Views