A review of calibration techniques for freehand 3-D ultrasound systems

Abstract

Three-dimensional (3-D) ultrasound (US) is an emerging new technology with numerous clinical applications. Ultrasound probe calibration is an obligatory step to build 3-D volumes from 2-D images acquired in a freehand US system. The role of calibration is to find the mathematical transformation that converts the 2-D coordinates of pixels in the US image into 3-D coordinates in the frame of reference of a position sensor attached to the US probe. This article is a comprehensive review of what has been published in the field of US probe calibration for 3-D US. The article covers the topics of tracking technologies, US image acquisition, phantom design, speed of sound issues, feature extraction, least-squares minimization, temporal calibration, calibration evaluation techniques and phantom comparisons. The calibration phantoms and methods have also been classified in tables to give a better overview of the existing methods.

Toward a Dynamic Approach of THA Planning Based on Ultrasound

“…The calibration allowed the computation of the transformation matrix required to obtain the 3-D positions of any points of the 2-D ultrasound image. The accuracy was less than 1 mm, which is similar to published results using nonautomatic and slower approaches [2,14,17].…”

“…This is therefore a crucial step for our application. Several methods can be found in the literature [14], however, some criteria are very important for clinical uses: accuracy, simplicity, robustness and rapidity. This appendix presents a fully automatic method based on a special phantom and on simulated data which can satisfy these constraints.…”

Rapid, easy and reliable calibration for freehand 3D ultrasound

“…It is crucial that probe calibration be as accurate as possible, as any errors will propagate through to subsequent stages of image analysis and measurement. The usual technique for 3D ultrasound calibration is to perform a series of scans of an object with known dimensions (a phantom) [13]. The simplest such object is a point fiducial formed by cross wires [4,10] or a small spherical ball [1,20] in a water bath.…”

Computer-Assisted Percutaneous Renal Access Using Intraoperative Ultrasonography

“…The u and v above are the column and row indices of the ultrasound image, and S x and S y are the scale factors with units of mm/pixel, respectively [6]. The point at position (u, v) in the ultrasound image is first scaled by S x and S y [7]. Then it is mapped to ultrasound probe coordinate system by transformation …”