Digital x-ray tomosynthesis: current state of the art and clinical potential

Abstract

Digital x-ray tomosynthesis is a technique for producing slice images using conventional x-ray systems. It is a refinement of conventional geometric tomography, which has been known since the 1930s. In conventional geometric tomography, the x-ray tube and image receptor move in synchrony on opposite sides of the patient to produce a plane of structures in sharp focus at the plane containing the fulcrum of the motion; all other structures above and below the fulcrum plane are blurred and thus less visible in the resulting image. Tomosynthesis improves upon conventional geometric tomography in that it allows an arbitrary number of in-focus planes to be generated retrospectively from a sequence of projection radiographs that are acquired during a single motion of the x-ray tube. By shifting and adding these projection radiographs, specific planes may be reconstructed. This topical review describes the various reconstruction algorithms used to produce tomosynthesis images, as well as approaches used to minimize the residual blur from out-of-plane structures. Historical background and mathematical details are given for the various approaches described. Approaches for optimizing the tomosynthesis image are given. Applications of tomosynthesis to various clinical tasks, including angiography, chest imaging, mammography, dental imaging and orthopaedic imaging, are also described.

Study of DQE dependence with beam quality on GE Essential mammography flat panel

“…As well, some improvements have been implemented in the latest GE mammographic detector that enhance the new detector for its potential use in tomosynthesis. ( 1 – 3 ) To determine how clinical FFDM is influenced by these modifications, a survey of mammographic screening carried out by the system was performed. Data from mammographic technique factors were collected and some conclusions were drawn.…”

Comparison of Reconstruction Algorithms for Decreasing the Exposure Dose During Digital Tomosynthesis for Arthroplasty: a Phantom Study

“…The FBP algorithm generally yields precise 3D reconstruction images [14]. In this study, the FBP images were reconstructed by a conventional Ramp or an SL filter kernel.…”

“…Digital tomosynthesis (DT) combines the benefits of digital imaging [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] with the tomographic benefits of computed tomography. The DT approach can be easily implemented in conjunction with radiography at reduced radiation doses and cost.…”

“…Hematoma or inflammation in the adjacent soft tissue must also be ruled out. However, artifacts greatly complicate the evaluation of these features, frequently rendering the images uninterpretable by conventional image reconstruction, even when hard convolution kernels (Ramp or Shepp-Logan (SL) filter kernel) are used such as filtered back projection (FBP) [14]. In DT, artifacts occur as very low signals along the sweep direction around the edges of highly attenuating materials such as metal prosthesis or osteosynthetic materials.…”

A software tool of digital tomosynthesis application for patient positioning in radiotherapy

“…The anatomical structures on DTS are clearly viewed on focal plane in the direction of central scan angle (such as 0° or 270°), but are less clear in the other directions due to the missing projection information from the other angles. Also, the anatomical structures on DTS planes are gradually blurred as they are off the focal plane 6 , 7 . Since the anatomical structures on DTS can be clearly viewed on the focal plane, target shifts in 2D DTS plane can be determined accurately, but the shift in the third dimension was unclear.…”