Tomosynthesis imaging: At a translational crossroads

Abstract

Tomosynthesis is a decades-old technique for section imaging that has seen a recent upsurge in interest due to its promise to provide three-dimensional information at lower dose and potentially lower cost than CT in certain clinical imaging situations. This renewed interest in tomosynthesis began in the late 1990s as a new generation of flat-panel detectors became available; these detectors were the one missing piece of the picture that had kept tomosynthesis from enjoying significant utilization earlier. In the past decade, tomosynthesis imaging has been investigated in a variety of clinical imaging situations, but the two most prominent have been in breast and chest imaging. Tomosynthesis has the potential to substantially change the way in which breast cancer and pulmonary nodules are detected and managed. Commercial tomosynthesis devices are now available or on the horizon. Many of the remaining research activities with tomosynthesis will be translational in nature and will involve physicist and clinician alike. This overview article provides a forwardlooking assessment of the translational questions facing tomosynthesis imaging and anticipates some of the likely research and clinical activities in the next five years. © 2009 American Association of Physicists in Medicine. ͓DOI: 10.1118/1.3120285͔ Key words: tomosynthesis, breast imaging, chest imaging, tomography I. OVERVIEWDigital tomosynthesis is a simple and relatively inexpensive method of producing section images using conventional digital x-ray equipment. It is a form of limited angle tomography that produces section, or "slice," images from a series of projection images acquired as the x-ray tube moves over a prescribed path. The total angular range of movement is often less than 40°. Because the projection images are not acquired over a full 360°rotation about the patient, the resolution in the z direction ͑i.e., in the depth direction perpendicular to the x-y plane of the projection images͒ is limited, and thus tomosynthesis does not produce the isotropic spatial resolution achievable with computed tomography ͑CT͒. However, the resolution of images in the x-y plane of the reconstructed slices is often superior to CT, and the ease of use in conjunction with conventional radiography makes tomosynthesis a potentially quite useful imaging modality.There has been a high degree of research interest in tomosynthesis imaging in the past decade, and at least two commercial products have recently been approved by the Food and Drug Administration ͑FDA͒ and released on the market. It is expected that other approved devices will soon follow. As such, tomosynthesis imaging is in a period of a high rate of change, with an increasing number of investigators and manufacturers nearing completion of projects involving both the physics and clinical aspects of the technique. If one were to compare the current state of tomosynthesis imaging to a metaphorical calendar year, the field is firmly in the middle of spring. It has moved beyond the "winter" of initial research ...

Antiscatter grid use in pediatric digital tomosynthesis imaging

“…In DT, tomographic slice images are reconstructed parallel to the detector plane from a series of discrete projection radiographs that are collected while the X‐ray tube sweeps through a limited angle above the detector. ( 6 ) Several recent studies have shown that the patient doses from DT can be significantly lower than CT for a number of diagnostic imaging applications. ( 7 – 11 ) Many recent studies into DT image quality have focused on chest and breast imaging in adults.…”

“…( 7 – 11 ) Many recent studies into DT image quality have focused on chest and breast imaging in adults. ( 6 ) Because of the relatively high diagnostic image quality and significantly reduced dose compared to CT, we feel that DT imaging may be particularly well‐suited to some applications in pediatric diagnostic imaging. We have begun to assess the diagnostic image quality of DT relative to digital radiography (DR) and CT. We are particularly interested in using DT in the diagnosis and follow‐up of lumbar spondylolysis, which is a relatively common cause of lower back pain in teenagers.…”

The TOMMY trial: a comparison of TOMosynthesis with digital MammographY in the UK NHS Breast Screening Programme – a multicentre retrospective reading study comparing the diagnostic performance of digital breast tomosynthesis and digital mammography with digital mammography alone

“…These observations suggested that DBT was unlikely to be used as a stand-alone imaging modality if a 2D mammogram was required for optimal microcalcification assessment. 25,52,53 Cancer detection and recall rate…”

“…25,26 A viewing workstation provides tools that enable the reader to scroll vertically through the tomographic images as well as to compare them with the corresponding 2D images.…”

Patchwork reconstruction with resolution modeling for digital breast tomosynthesis

“…A three dimensional imaging technique, like digital breast tomosynthesis (DBT), may be able to solve this problem by removing interference from overlapping dense tissue [3]. Current experience shows that visualization of masses is much improved [4], but problems remain for micro-calcifications [5,6].…”