Articles – DTS – Digital Tomosynthesis Society

As part of its mission, the Digital Tomosynthesis Society actively promotes the benefits and diversity of tomosynthesis’ benefits. Below are the latest articles authored by DTS Society leadership appearing in media nationwide:

Digital tomosynthesis – The other 3D modality – poised for major growth

By Dr. Michael Yuz

This article is reprinted with permission from HealthCare Business News

October 07, 2022

Medical imaging is an ever-evolving discipline. And it isn’t uncommon that, with innovation and technical advances, what’s old is new again. Keep your eye on the ball!

A case in point is tomosynthesis. Long after its introduction, the modality gained prominence as digital breast tomosythesis (DBTS) in breast cancer screening in 2011. Today, with continued evolution, its use is growing significantly for a wide range of additional clinical applications. Many believe that DTS may just be poised to replace X-ray as the most commonly used imaging modality worldwide for many of these new use cases.

What is so notable about DTS? While DTS relies on an X-ray tube and image receptor, unlike conventional 2D X-ray, DTS is a volumetric modality. It yields far greater information than conventional X-ray, without the cost, mechanical and operational complexities as well as radiation exposure of 3D CT. Helping it along is a recent effort to broaden the modality’s accessibility with delivery through a medical scanning as a service (MSaaS) model. This pay-per-scan fee structure eliminates capital equipment expenditures, which is greater than for X-ray, addressing one of the barriers that prevent some practices from adopting the imaging technique.

The DTS MSaaS offering also includes an optional cloud-based teleradiology service using experts in the modality. This eliminates learning curves and allows specialists of every stripe to offer this advanced imaging in-house when needed to boost patient care.

Tomosynthesis: Historical overview
A refresher course: The roots of tomosynthesis date back to the 1930s and geometric tomography. Early tomography devices were an effort to compensate for a major shortcoming of conventional X-ray: projecting a 3D volume on a 2D plane, which superimposes underlying and overlying structures on the region-of-interest and potentially obscures clinically important information. To compensate, early tomography relied on the simultaneous movement of the X-ray tube and detector around a designated point in the patient being imaged. The result was a slice image that sharpened the details of structures closest to the detector, while blurring those further away.

During the years that followed, the advent of the digital detector enabled faster and more sophisticated image capture. New, powerful computers also supported reconstruction of multiple image slices that could be used to synthesize any coronal plane in the body, providing physicians with far greater clinical information.

CT vs. tomosynthesis
The most advanced tomographic imaging modality is CT, which acquires data over a 360 degree rotation around the patient. However, this brings with it design and operational complexities, higher personnel costs and the need for specialized expertise, as well as long scan times.

By contrast, unlike CT, DTS relies on a limited range of angular movement across the patient—often 40 degrees or less. This involves less time and intricacies than CT but limits Z-direction data and isotropic special resolution. However, x-y plane information is often superior to CT and the resulting image is far superior to X-ray.

When CT is not readily available or appropriate, most physicians continue to rely on conventional X-ray. In fact, X-ray is the most commonly used imaging modality overall, accounting for as much as 60% of total imaging volume. However, as DTS evolves and becomes increasingly cost-effective and accessible to medical practices, for a growing number of physicians, it may emerge as a preferable alternative to X-ray, filling the imaging gap. With an MSaaS delivery model, streamlined outsourced interpretation and continued maturation of the modality itself, use is likely to grow.

Interest and use cases expand
A number of well-known medical equipment vendors and innovative smaller firms are focusing renewed efforts on DTS and enhancing its performance. During the 1990s, the introduction of flat-panel digital detectors gave DTS a significant boost in acquisition speed, while reducing image noise and distortion. Today, devices and imaging techniques also are being developed to enhance image quality and support a growing number of clinical applications.

For example, detector-tube geometry of motion has become more varied. In some cases, the two components remain in parallel planes, maintaining fixed positions relative to one another as they move in an arc. Alternately, in other devices, the detector remains stationary as the tube arcs over the patient. Each method has benefits in specific applications.

In addition, reconstruction and depth resolution algorithms are being constantly refined. All reconstruction algorithms compensate for potential anatomic distortion as the arc rotation of objects projected onto the detector plane. Acquisition parameters, including tube movement, angle and number of images, are now being optimized for various clinical uses.

Additionally, because DTS datasets are digital, both computer aided diagnosis (CAD) and artificial intelligence (AI) can play a role in exam interpretation. With the development of appropriate algorithms, CAD and AI can speed interpretation and potentially enhance results.

In recent times, these changes have stepped up the modality’s usefulness in a much wider range of clinical applications. While further studies are warranted, research has been extremely promising in key areas in addition to the well-known benefits in breast cancer screening.

Highlights include:

Chest
Diagnosis of suspected pulmonary lesions, elimination of false positives and follow up of known nodules. It also has applications in cystic fibrosis, tuberculosis and asbestos-related diseases. Further, DTS may be a useful substitute for CT in COVID diagnosis.

Abdomen
Evaluation of a range of abdominal anatomical structures and in helping to diagnose urinary tract calculus disease.

Fractures
Significant improvement over X-ray in detecting both routine and micro- and occult- bone fractures. Notably, missed fractures on X-ray constitute 80% of all missed diagnoses.

Rheumatology
Imaging joint spaces and erosions and detection of degenerative and inflammatory arthritis. It also can be used in evaluating osteoarthritis, rheumatoid arthritis and gout.

Head & Neck
Sinus imaging and diagnosis of TMJ dislocations and orbital fractures. It also has demonstrated success in dental implant planning.

The sky is the limit
Significantly, with an MSaaS delivery model, outsourced reading and a part-time technologist, specialists at freestanding practices treating many of these conditions can more easily provide DTS exams in-house. There is no need to maintain a critical exam volume to justify costs. In addition, rapidly growing DTS technology coupled with this innovative delivery model can provide a comprehensive, accessible and affordable imaging ecosystem that can be implemented anywhere.

About the author: Michael Yuz, MD, is a board-certified diagnostic radiologist, with extensive experience in advanced modalities, including MRI and Cardiac CT. A serial entrepreneur, he is founder, CEO and Executive Radiologist of USARAD, a major teleradiology firm. Dr. Yuz trained at several preeminent healthcare institutions, including New York University and Thomas Jefferson and received an MBA in Healthcare from George Washington University. He previously held positions as Chief Radiologist, Director of a Cardiovascular CT laboratory and Head Medical Instructor for a Cardiovascular and Body Section program at the major University teaching program.

Broader Horizons

By Michael Yuz, MD, MBA; Peter Dawson, FRCP, FRCR; and Floyd Katske, MD
Reprinted from: Radiology Today
June/July, 2022, Vol. 23, No. 4, P. 10-11

Fast, low-dose, 3D tomosynthesis diversifies into a growing range of applications.

For most people in the radiology field, the term tomosynthesis conjures up thoughts of breast imaging. Since receiving FDA clearance in 2011 for screening mammography, digital tomosynthesis (DTS) technology has become virtually synonymous with 3D breast exams, and many clinicians are unaware of its emerging benefits in a far wider range of imaging applications. While not yet routine in most imaging facilities, DTS has significant advantages over the competing modalities of X-ray and CT in many applications, and its versatility will only grow in the future.

As a volumetric modality, DTS provides far greater anatomic detail than conventional 2D X-ray. Through capture of thin anatomic slices, it reduces the interference of overlapping tissue that can obscure clinically significant abnormalities on patient images. At the same time, DTS imaging is far less involved than CT. In particular, image acquisition and processing are faster, and today’s devices are less costly and easier to use, and occupy far less real estate than CT. Significantly, DTS involves much less patient radiation exposure.