Breaking the Silence on Bone Conditions
By Rebecca Montz, EdD, MBA, CNMT, PET, RT(N)(CT), NMTCB RS
Radiology Today
Vol. 24 No. 5 P. 18

Recent advances help radiologists assess bone health.  

While bone disease may not get as much attention as heart disease, cancer, and other major diseases, it is common, especially among the elderly, and is a burden on overall health status. Although some bone diseases lead directly to pain and deformity, bone disease often is a “silent” disorder until it causes fractures. The Global Burden of Disease reported that approximately 1.71 billion people have musculoskeletal conditions worldwide. Due to population growth and aging, the number of people living with musculoskeletal conditions will continue to increase, creating a health care crisis. The major problem created by bone disease, especially osteoporosis, is fractures, which may be the first visible sign of disease in patients. According to the Office of the Surgeon General, each year, an estimated 1.5 million individuals suffer a fracture due to bone disease, with osteoporosis being the most common cause. 

Fractures are a costly and chronic problem for individuals and society. According to the Bone Health & Osteoporosis Foundation (BHOF), osteoporosis related to bone fractures costs patients, families, and health care systems $19 billion annually. The BHOF estimates that by 2025, osteoporosis will be responsible for three million fractures resulting in $25.3 billion in costs. According to the BHOF, approximately 10 million people in the United States aged 50 and older have osteoporosis, while another 44 million have low bone mass, putting them at increased risk for osteoporosis. Other bone disorders, such as Paget’s disease of bone, hyperparathyroidism, osteogenesis imperfecta, rickets, and osteomalacia, are less common but contribute to the overall health care crisis.

Digital X-ray is often the first choice for evaluating bone injuries and related diseases. It supplies an immediate result and is particularly useful for detecting fractures, injuries, bone lesions/tumors, and joint abnormalities. While it is the most useful exam to detect fractures, it does not identify patients at risk for future fractures. Dual-energy X-ray absorptiometry (DXA) and dynamic DR (DDR), along with AI software, continue to play a crucial role in the assessment of bone health by identifying patients at risk for fractures. DXA has long been the gold standard for diagnosing osteoporosis and has advanced due to technology and AI software.

Underutilized Tool
Osteoporosis is a major public health problem worldwide, with approximately 8.9 million osteoporotic fractures occurring annually, reports the International Osteoporosis Foundation. Osteoporosis has been referred to by many health care providers as the silent pandemic; it is a global health care problem because osteoporosis and bone fragility are asymptomatic prior to a fracture. Therefore, osteoporosis often receives less attention from governments and health care providers when compared with other chronic diseases.

DXA is a specialized type of X-ray imaging that measures bone mineral density (BMD) and has been a widely accepted technology for the assessment of BMD. The test measures calcium and other minerals in the bones to diagnose osteopenia and osteoporosis, along with predicting risk of future bone fractures. It identifies a quantity of bone in at least two locations on the body, usually the lower spine and one or both hips.

The World Health Organization’s operational definition of osteoporosis is based on a DXA measurement of BMD at least 2.5 standard deviations below the mean of a young adult reference population (T-score ≤ -2.5). The World Health Organization’s biological definition of osteoporosis takes into consideration both density and microarchitecture, which is measured as a trabecular bone score (TBS). Before the introduction of TBS, only one-half of the definition was possible to assess with DXA. The complete definition can be assessed with BMD (density) and TBS (microstructure), thereby providing a more accurate assessment of osteoporosis and fracture risk.

Often the Fracture Risk Assessment Tool (FRAX) is combined with DXA to enhance the prediction of a patient’s fracture risk because it considers BMD measurement by DXA as well as other risk factors, including gender, age, and previous fragility fractures. However, FRAX scores do not typically affect clinical management in patients who have an established diagnosis of osteoporosis or patients with normal BMD. It is useful, however, in the management of patients with osteopenia.

Although DXA is inexpensive, provides valuable results, and delivers a low dose of radiation, it is often underutilized. Orit Wimpfheimer, MD, the CMO and vice president of product strategy at Nanox, says that although DXA is an effective modality, only 20% to 30% of patients entitled to DXA exams get them. “There isn’t enough being done to identify patients with osteoporosis early on, which is causing a worldwide crisis in bone health,” she says.

AI Enhancements
Historically, osteoporosis has been difficult to diagnose and manage because it is a silent disease until a fracture occurs. However, the introduction of AI software has allowed radiologists to use current imaging devices and/or images to gather additional clinical information that aids in diagnosis, as well as the assessment of bone health and fracture risk. This increases radiologists’ role in the assessment and management of osteoporosis and other bone diseases.

Medimaps Group’s TBS Osteo software application has been used for years in clinical practice to better predict osteoporotic fracture risk. TBS Osteo has been used in more than 950 peerreviewed publications worldwide on more than 75,000 patients to show clinical efficacy and medical acceptance. Additionally, more than 500,000 procedures utilizing the software are performed in a year in the United States alone, according to Medimaps Group.

The tool installs on existing DXA or X-ray scanners to produce a rapid analysis of estimated fracture risk, based on a determination of bone texture, independently and in addition to risks determined by BMD, clinical risk factors, and FRAX. Together, BMD and TBS Osteo can identify individuals at high risk of fracture, inform treatment decision-making, and assess the efficacy of treatment strategies. Another notable advantage is that it has an independent CPT code for US reimbursement not tied to DXA reimbursement. As of January 1, 2022, Medicare has assigned a payment to Category 1 CPT codes established for TBS Osteo.

“We are hopeful that this will provide better access to TBS, leading to improved fracture risk assessment in osteoporosis and, consequently, improve patient care,” says Lauren Nicola, MD, CEO of Triad Radiology Associates.

Nicola says TBS Osteo uses the DXA image of the lumbar spine and creates a grayscale pixel image of the vertebral trabecular bone microstructure. The resulting image provides an indirect measure of the bone texture and trabecular microarchitecture. She says the tool can reduce the number of osteoporotic fractures by finding high risk patients sooner, more comprehensively classifying fracture risk, and better directing therapy.

Karen Hind, PhD, the director of clinical affairs at Medimaps Group, and Shelley Horn, DVM, MBA, the chief business development officer at Medimaps Group, believe that the most exciting advancements in bone health assessment will be AI software solutions that can supply more information from routine X-rays. AI solutions will go beyond the traditional assessment provided by radiologists and supply clinical information such as BMD/TBS and fracture risk, which will improve the sensitivity and specificity of bone health assessments and help clinicians make more informed decisions about patient care.

Nanox.AI, the deep-learning medical imaging analytics subsidiary of Nanox, is a medical software company that offers AI medical imaging solutions to screen for early signs of chronic disease in large populations. Nanox.AI’s portfolio includes an FDA-cleared imaging solution for bone health, HealthOST, that uses routine CT imaging to help physicians identify the early signs of osteoporosis. The FDA has also recently cleared Nanox.ARC, a 3D digital multisource system.

Wimpfheimer says AI can potentially screen through imaging cases to target identification of low BMD and vertebral body compression fractures, which are often not included in radiology reports, to direct high-risk patients to early preventative treatments. She points out that although the number of radiologists has not changed much in the past 20 years, the number of images per scan has drastically increased. This creates an opportunity for AI to help radiologists utilize the vast imaging data that are available to take preventative action against osteoporosis.

In March 2023, a HealthOST clinical study report evaluated 265 routine CT scans and found that 26% of patients had at least one vertebral compression and/or low BMD that otherwise may have been undetected. Another study examined 11,012 eligible CT scans and confirmed 24.3% positive for vertebral fracture, with less than 50% of them reported in the original radiology report.

“There are valuable data being missed that can aid in the bone health crisis worldwide,” Wimpfheimer says.

Moving Pictures
Clinicians are also utilizing DDR, a low-dose X-ray imaging technique that enables visualization of anatomy in motion, including the interaction of bones, tissue, and organs, to investigate bone health. “Clinicians can now see more with a dynamic X-ray,” says Guillermo Sander, PhD, the director of DR at Konica Minolta Healthcare Americas. “Because DDR is another X-ray technique using the same X-ray system, the equipment and technologist workflow is the same. It just adds an extra minute of time.”

Konica Minolta Healthcare has multiple DDR X-ray systems that are being used to observe physiology in motion, such as the KDR Advanced U-Arm, KDR Flex Overhead, and the mKDR Xpress mobile system. DDR is an enhanced version of a standard DR system that acquires up to 15 sequential radiographs per second, allowing clinicians to observe physiological cycles, as well as individual radiographic images (up to 17”x 17” in size). Up to 300 images are acquired in 20 seconds to create a “cine loop” with a dose equivalent to about two standard X-rays.

Having a full view of the musculoskeletal system in motion, in either weight-bearing or resting positions, helps orthopedic specialists provide faster and more detailed diagnoses to improve the quality of care. DDR can be used to assess instability, musculoskeletal injury, sources of pain, and treatment follow-up of any joint throughout its range of motion— whether it be the neck, spine, shoulders, or knees. “The fact that you’re seeing how the joint itself is moving when a patient is having pain is an inherent advantage,” says Eric Wagner, MD, an assistant professor and director of upper extremity research at Emory Healthcare. “Most of the time, the patient is not coming to you because their shoulder hurts at rest; they are coming to you because their shoulder hurts when they are trying to move it for certain activities. This imaging allows you to see how the joint is moving during these activities.” With DDR, orthopedists can quantify the dynamic relationship between bones and soft tissue through the full range of motion.

Combating Bone Disease
Bringing the knowledge gained from bone health and fracture risk assessments to patients so they can understand and act is the goal for any technological advances in bone health assessment and management. Patient education and engagement are critical for improving patient outcomes and reducing the burden of osteoporosis on health care systems. By providing patients with actionable information about their bone health, they can be empowered to make informed decisions about their lifestyle and treatment options, leading to better outcomes, Horn says.

E. Michael Lewiecki, MD, a clinical assistant professor of medicine at the University of New Mexico School of Medicine and director of New Mexico Clinical Research & Osteoporosis Center in Albuquerque, sees a need for more patient advocacy and identifying patients at risk. “There is a crisis in osteoporosis care worldwide,” he says. “Every effort to do a better job in identifying and treating these patients will help reduce the burden of osteoporotic fractures.”

In the future, AI and machine learning will play an increasing role in augmenting radiologists’ diagnoses, with algorithms that go beyond pattern recognition and other basic forms of AI available today, says Kirsten Doerfert, senior vice president of marketing for Konica Minolta Healthcare Americas. She believes these initial steps in image analysis are important, however, as they are the groundwork for what will come over the next decade, as AI continues to advance and provide additional valuable, actionable insights.

“As intelligent analytics mature, it will be possible to compare the individual to the universe of patients with similar characteristics to provide more predictive and prescriptive personalized patient care,” Doerfert says. “Radiologists have the chance to be at the forefront of this transformation.” 

— Rebecca Montz, EdD, MBA, CNMT, PET, RT(N)(CT), NMTCB RS, has worked at the Mayo Clinic Jacksonville and University of Texas MD Anderson Cancer Center in Houston as a nuclear medicine and PET technologist.