Flat-panel detector-based cone beam volume CT breast imaging: detector evaluation

Abstract

Preliminary evaluation of large-area flat panel detectors (FPDs) indicates that FPDs have some potential advantages over film-screen and CCD-based imagers: compactness, high resolution, high frame rate, large dynamic range, small image lag (<1%), and excellent linearity (~1%). A real time large-area flat panel detector (FPD) Varian PaxScan 2520 was evaluated for cone-beam volume breast imaging (CBVCTBI) in terms of dynamic range, linearity, image lag, and spatial as well as low contrast resolution. In addition, specially made breast phantoms were imaged with our prototyped CBVCTBI system to provide real outcomes to evaluate the detector under full imaging system conditions including the x-ray source, gantry geometry, x-ray technique selection, data acquisition system and reconstruction algorithms. We have concentrated on the low kVp range (30 to 80 kVp) in the context of the breast-imaging task. For ~288 images/scan the exposure required was ~2.5mR/projection. This is equivalent to that of a conventional mammography screening exam. The results indicate that the FPD-based CBVCTBI system can achieve sufficient high-and low-contrast resolution for diagnostic CBVCT breast imaging with a clinically acceptable exposure level. The advantages of the new FPD make it a promising candidate for CBVCTBI.

Evaluation of flat panel detector cone beam CT breast imaging with different sizes of breast phantoms

“…Specificity and the positive predictive value of mammography remain limited owing to an overlap in the appearances of benign and malignant lesions, and surrounding structure. We propose to address the limitations accompanying conventional mammography by incorporating a cone beam CT reconstruction technique with a recently developed flat panel detector (FPD) [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. With this technique, threedimensional (3D) reconstructions of a breast from a single fast volume scan (5-10 seconds) can be obtained.…”

Preliminary system characterization of flat-panel-detector-based cone-beam CT for breast imaging

“…Specificity and the positive predictive value of mammography remain limited owing to an overlap in the appearances of benign and malignant lesions, and surrounding structure. We propose to address the limitations accompanying conventional mammography by incorporating a cone beam CT reconstruction technique with a recently developed flat panel detector (FPD) [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. A conceptual design of the proposed FPD-based cone beam computed tomography breast imaging (CBCTBI) system is shown in Figure 1.…”

“…Due to then-immature CT technology, long scanning time, relatively low spatial resolution, and sub-optimal detector and x-ray technique used, it was not conclusive from the results of those studies that the fan beam CT mammography of that time was superior to the contemporary conventional mammography [11][12]. A group presented the concept of a dedicated fan beam CT for breast imaging [19].…”