Fractures
The adult human skeleton is made up of 206 bones (270 at birth). These include the bones of the skull, spine (vertebrae), ribs, arms and legs. Fractures are incredibly common and in fact, globally, the person-yearly fracture incidence rate is 1.2%1, 2. In the US alone, 2 million fractures occur each year, including those related to osteoporosis. Many radiologists, especially those in emergency departments and urgent care settings, agree that missing a fracture on 2D X-ray is the most common misdiagnosis accounting for approximately 80% of missed diagnoses2, 3.
Digital tomosynthesis therefore can offer significant improvement over X-ray diagnosis, either as an additional tool or as a routine for fracture diagnosis. Due to its innate advantages over 2D X-ray, DTS has been described in the literature as offering improved detection of not only routine fractures but also of micro and occult bone fractures, which can typically be detected only by CT or MRI4. Digital tomosynthesis has been noted to be especially useful in delineating certain complex anatomical structures, including skull, TMJs, facial bones, atlanto-axial joints and carpal and tarsal bones5.
Joint Imaging in Rheumatology
The most utilized imaging modality for evaluation of bones and joints is plain radiography. However, this is also the least sensitive technique for abnormalities compared to CT and MRI. CT of bones and joints is a significant burden on radiologists since these studies contain hundreds of images and is an expensive and not always readily available tool. MRI, while an unmatched modality for the demonstration of soft tissues, including ligaments, menisci and tendons, has significant limitations in the evaluation of the bone itself. Digital tomosynthesis is a good solution for addressing these limitations.
A useful application for arthropathies has also been demonstrated, with outstanding imaging of joint spaces and erosions, suggesting digital tomosynthesis may become an important element in screening and monitoring of arthropathies5-7. Several studies have noted that DTS can improve the detection of degenerative and inflammatory arthritis including subtle findings such as erosions. Further studies are needed but it would seem likely that digital tomosynthesis may become the modality of choice for the evaluation of various common conditions in this category including osteoarthritis, rheumatoid arthritis and gout5-7.
1 Camilla Bergh et al 2020 Fracture incidence in adults in relation to age and gender: A study of 27,169 fractures in the Swedish Fracture Register in a well-defined catchment area. PLOS One December 21, 15 (12)
2 Antono Pinto et al 2018. Traumatic fractures in adults: missed diagnosis on plain radiographs in the Emergency Department. Acta Biomed 89(Suppl 1), 111–123.
3 Mattijssen-Horstink, L et al 2020. Radiologic discrepancies in diagnosis of fractures in a Dutch teaching emergency department: a retrospective analysis. Scandinavian Journal of Trauma, esuscitation and Emergency Medicine 28, Article number: 38 (2020).
4 Blum, A et al 2018. Tomosynthesis in musculoskeletal pathology. Diagnostic and Interventional Imaging 99, 423++-441.
5 Duryea J, Dobbins JT, Lynch J. A 2003. Digital tomosynthesis of hand joints for arthritis assessment, Med. Phys 30, 325–333 (2003).
6 Canella, C et al 2011. Use of Tomosynthesis for Erosion Evaluation in Rheumatoid Arthritic Hands and Wrists. Radiology 258, No. 1. https://pubs.rsna.org/doi/full/10.1148/radiol.10100791
7 Paolo Simoni et al 201. Use of tomosynthesis for detection of bone erosions of the foot in patients with established rheumatoid arthritis: comparison with radiography and CT. American Journal of Roentgenology 205, 364-370.