CT Bone Density Study - CAM 748HB

Bone mineral density (BMD) measurement identifies patients with low bone density and increased fracture risk. Methods for measuring BMD are non-invasive, painless, and available on an outpatient basis. Dual energy x-ray absorptiometry (DXA), previously referred to as DEXA, is the most commonly used method of evaluating BMD and is the only BMD technology for which World Health Organization (WHO) criteria for the diagnosis of osteoporosis can be used. Patients who have a BMD that is 2.5 standard deviations below that of a "young normal" adult (T-score at or below -2.5) are deemed to have osteoporosis. Quantitative computed tomography (QCT) has not been validated for WHO criteria but can identify patients with low BMD compared to the QCT reference database, and it can be used to identify patients who are at risk of fracture.

DXA — Dual energy X-ray absorptiometry (DXA) is most often used to measure bone mineral density due to its low radiation exposure, low precision error, and capacity to measure multiple skeletal sites (spine, hip, or total body).

Axial DXA — This provides the "gold standard." Axial DXA predicts fracture risk at the site being measured.

Peripheral DXA — This device measures BMD at peripheral sites, generally at the heel or wrist. It is relatively cheap and portable and is an option when there is limited access to axial DXA.

Quantitative computed tomography (QCT) — QCT measures volumetric integral, trabecular, and cortical bone density at the spine and hip and can be used to determine bone strength. Radiation dose is increased when compared with DXA. Indications are the same for QCT as DXA; however, DXA is recommended as the first-line test in most cases (ACR 2016; Cosman, 2014).

Fracture Risk Assessment* — The fracture risk assessment (FRAX) tool developed by the World Health Organization estimates the 10-year risk of having a fracture based on factors such as age, sex, body mass index (BMI), previous fractures, parental fracture history, glucocorticoid use, Rheumatoid arthritis, and conditions predisposing to secondary osteoporosis (insulin-dependent diabetes, osteogenesis imperfecta in adults, untreated long-standing hyperthyroidism, hypogonadism or premature menopause ( < 45 years), chronic malnutrition, or malabsorption and chronic liver disease) and tobacco and alcohol use. Based on FRAX, a 65-year-old woman, without any additional conditions increasing fracture risk, has a 9.3% 10-year risk of developing a fracture. This value is therefore used as the risk level cut-off recommending screening in patients younger than 65 (CMBD, 2019). 

Ethnicity and Screening — Due to the potential negative consequences of fractures and the lack of an optimal age at which to screen populations of different ethnicity, the USPSTF now recommends screening all women aged 65 and older regardless of race and ethnicity.

Follow up Imaging — Follow-up imaging is performed on patients at risk of developing osteoporosis or to evaluate the outcome of osteoporosis treatment. Follow-up imaging is generally performed at 1 – 2 years after initiation of therapy for osteoporosis and subsequently every 2 years unless clinical circumstances prompt earlier imaging. In patients at increased risk for developing osteoporosis, imaging may be performed more frequently, particularly with patients with certain medical conditions and taking medications predisposing to fracture. The later population includes those undergoing long-term therapy with common medications such as heparin or glucocorticoids.


For first time baseline study1,2,3,4,5

Patient with suspected osteoporosis or osteopenia meeting any of the following criteria when DXA scanning is not available or for patients with advanced degenerative changes of the spine or who are severely obese (BMI > 35 kg/m) that may limit the efficacy of DXA scans.

  • Asymptomatic women 65 years of age or older
  • For post-menopausal women age < 65 or during the menopause transition, and men < 70 having at least one of the following risk factors for low bone mass or fractures:
    • Low body weight ( < 127 lb. or 57.6 kg or BMI < 20 kg per m)
    • A history of fracture
    • History of maternal hip fracture that occurred after the age of 50 years
    • High risk medications (e.g., steroids or glucocorticosteroids, medroxyprogesterone acetate, anticonvulsants, heparin, lithium, estrogen receptor modulators, calcitonin, or bisphosphonates)
    • History of estrogen deficiency
    • Conditions that cause or contribute to osteoporosis and fractures (e.g., malabsorption syndromes, inflammatory bowel disease and other gastrointestinal conditions, metabolic bone disease, hyperparathyroidism, hypogonadism, thyroid hormone therapy or hyperthyroidism, chemotherapy, long-term heparin therapy, rheumatologic and autoimmune diseases, renal failure, hematologic disorders, multiple myeloma, chronic alcoholism, cerebral palsy, etc.)
  • Men aged 70 or older
  • Individuals with fragility fractures, including vertebral abnormalities that are indicative of osteoporosis, osteopenia, low bone mineral content, or vertebral fractures seen on other imaging studies/X-ray
  • Individuals aged 50 years and older who develop a wrist, hip, spine, or proximal humerus fracture with minimal or no trauma, excluding pathologic fractures
  • Loss of body height (> 4 cm (> 1.5 inches))1
  • Amenorrhea for greater than 1 year before the age of 42
  • Eating disorders, including anorexia nervosa and bulimia
  • Individuals who have had gastric bypass for obesity (accuracy of DXA may be affected by obesity)

Follow-up of individuals with known osteoporosis or osteopenia6,7

  • In women with low to moderate risk reassess fracture risk in 2 – 4 years
  • In post-menopausal women with a low bone mineral density at high risk for fractures on treatment, monitor the spine and hip every 1 – 3 years
  • For patients on bisphosphonates, reassess fracture risk every 3 – 5 years
  • No previous bone density within past 23 months AND meets any one of the above risk factor criteria. (More frequent BMD testing may be warranted in certain clinical situations and should be determined on a case-by-case basis.)

Indications for QCT/pQCT in pediatric and adolescent include:8

  • Individuals receiving (or expected to receive) glucocorticoid therapy for more than 3 months.
  • Individuals receiving radiation or chemotherapy for malignancies.
  • Individuals with an endocrine disorder known to adversely affect BMD (e.g., hyperparathyroidism, hyperthyroidism, growth hormone deficiency or Cushing’s syndrome).
  • Individuals with bone dysplasias known to have excessive fracture risk (osteogenesis imperfecta, osteopetrosis) or high BMD, such as prolonged exposure to fluoride.
  • Individuals with medical conditions that could alter bone marrow density, such as: (chronic renal failure, inflammatory arthritides, eating disorders, organ transplantation, prolonged immobilization, sprue, inflammatory bowel disease, malnutrition, cystic fibrosis, osteomalacia, acromegaly, cirrhosis, HIV infection, prolonged exposure to fluorides, and hematologic disorders [thalassemia, sickle cell disease]).


  1. Affordable Care Act (ACA) Nondiscrimination in Health Programs and Activities; §92.206 Equal Program Access on the Basis of Sex; Final Rule, [Section 1557]. Federal Register (May 18, 2016). https://federalregister.gov/a/2016-11458.
  2. American College of Radiology (ACR). ACR Appropriateness Criteria®. https://acsearch.acr.org/docs/69358/Narrative/. Published 2016.
  3. Cosman F, De Beur SJ, LeBoff MS, et al. Clinician’s guide to prevention and treatment of osteoporosis. Osteoporos Int. 2014; 25(10):2359-2381. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4176573/. https://my.nof.org/file/bonesource/Clinicians-Guide.pdf. Retrieved December 28, 2017.
  4. Curry SJ, Krist AH. Screening for Osteoporosis to Prevent Fractures: US Preventive Services Task Force Recommendation Statement. JAMA. 2018 Jun 26;319(24):2521-2531.
  5. Eastell R, Clifford CJ, Black DM, et al. Pharmacological Management of Osteoporosis in Postmenopausal Women: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2019 May; 104(5):1595–1622.
  6. Centre for Metabolic Bone Diseases (CMBD). Fracture Risk Assessment Tool (FRAX). Published April 26, 2019. Accessed August 19, 2021. https://www.sheffield.ac.uk/FRAX/tool.jsp.
  7. International Society for Clinical Densitometry (ISCD). Official Positions: 2019 Adult https://www.ISCD.com.
  8. Jeremiah MP, Unwin BK, et al. Diagnosis and Management of Osteoporosis. American Family Physician. 2015;92(4):261-268.
  9. Panday K, Gona A, Humphrey MB. Medication-induced osteoporosis: screening and treatment strategies. Ther Adv Musculoskelet Dis. October 2014; 6(5):185-202. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4206646/. Retrieved January 10, 2018.
  10. Shoback D, Rosen CJ, et al. Pharmacologic Management of Osteoporosis in Postmenopausal Women: An Endocrine Society Guideline Update. J Clin Endocrinol Metab. 2020; 105(3):587-594.
  11. Unnanuntana A, Gladnick BP, Donnelly E, et al. The assessment of fracture risk. J Bone Joint Surg Am. March 2010; 92(3):743-753. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2827823/
  12. US Preventive Services Task Force (USPSTF). Recommendation Statement. JAMA. 2018;319(24):2521-2531.
  13. Ward RJ, Robert CC, Bencardino JT, et al. ACR Appropriateness Criteria®. Osteoporosis and bone mineral density. J Am Coll Radiol. May 2017; 14 Suppl 5: S189-202. http://www.jacr.org/article/S1546-1440(17)30198-9/fulltext#sec1.3.3.
  14. Yin MT, RoyChoudhury A, Nishiyama K, et al. Bone density and microarchitecture in hepatitis C and HIV-coinfected postmenopausal minority women. Osteoporos Int. 2018 Apr; 29(4):871-79. Epub 2018 Feb 1.

Coding Section

Code Number Description
CPT 77078 Computed tomography, bone mineral density study, 1 or more sites, axial skeleton (eg, hips, pelvis, spine)

Procedure and diagnosis codes on Medical Policy documents are included only as a general reference tool for each policy. They may not be all-inclusive.

This medical policy was developed through consideration of peer-reviewed medical literature generally recognized by the relevant medical community, U.S. FDA approval status, nationally accepted standards of medical practice and accepted standards of medical practice in this community, Blue Cross Blue Shield Association technology assessment program (TEC) and other nonaffiliated technology evaluation centers, reference to federal regulations, other plan medical policies, and accredited national guidelines.

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