Osteoporosis Spine Imaging¶

Definition¶

Osteoporosis is the most common metabolic bone disease, characterized by decreased bone mineral density and structural deterioration of bone tissue. The spine is one of the most commonly affected sites, with vertebral compression fractures being the most frequent osteoporotic fracture type — approximately 700,000 per year in the United States.

Imaging¶

DXA¶

Gold standard for bone density measurement
T-score ≤ -2.5 = osteoporosis; -1.0 to -2.5 = osteopenia
Lumbar spine and hip are standard measurement sites
Degenerative changes, aortic calcification, and compression fractures can falsely elevate lumbar DXA scores

Radiography/CT¶

Diffuse osteopenia with thinned cortices and prominent vertical trabeculae
Compression fractures — anterior wedge, biconcave ("fish vertebra"), or crush deformity
Radiographs are insensitive — 30–50% bone loss required before visible
Quantitative CT (QCT) measures volumetric density, avoiding DXA confounders

MRI¶

STIR identifies acute fractures (marrow edema)
Distinguishes osteoporotic from malignant compression fractures

Clinical Pearl

The "fish vertebra" — biconcave vertebral body deformity from symmetric endplate compression — is characteristic of osteoporosis, resulting from weakened bone yielding to disc pressure. Multiple fish vertebrae suggest diffuse osteoporosis. A similar deformity in sickle cell disease shows central endplate depression ("H-shaped" vertebra).

Key Points¶

DXA T-score ≤ -2.5 defines osteoporosis
Vertebral compression fractures are the most common osteoporotic fractures
Radiographs are insensitive for early osteoporosis
MRI with STIR differentiates acute from chronic fractures and benign from malignant
Fish vertebrae indicate diffuse bone weakening

References¶

Yu JS, Krishna NG, Fox MG, et al. ACR Appropriateness Criteria® Osteoporosis and Bone Mineral Density: 2022 Update. J Am Coll Radiol. 2022;19(11S):S417-S432. https://pubmed.ncbi.nlm.nih.gov/36436967/
Porter JL, Varacallo MA. Osteoporosis. In: StatPearls. Treasure Island (FL): StatPearls Publishing; updated 2023 Aug 4. https://www.ncbi.nlm.nih.gov/books/NBK441901/
Lenchik L, Weaver AA, Ward RJ, Boone JM, Boutin RD. Opportunistic Screening for Osteoporosis Using Computed Tomography: State of the Art and Argument for Paradigm Shift. Curr Rheumatol Rep. 2018;20(12):74. https://pmc.ncbi.nlm.nih.gov/articles/PMC7092507/
Jang S, Graffy PM, Ziemlewicz TJ, Lee SJ, Summers RM, Pickhardt PJ. Opportunistic Osteoporosis Screening at Routine Abdominal and Thoracic CT: Normative L1 Trabecular Attenuation Values in More than 20 000 Adults. Radiology. 2019;291(2):360-367. https://pubmed.ncbi.nlm.nih.gov/30912719/
Grigoryan M, Guermazi A, Roemer FW, Delmas PD, Genant HK. Recognizing and reporting osteoporotic vertebral fractures. Eur Spine J. 2003;12(Suppl 2):S104-S112. https://pmc.ncbi.nlm.nih.gov/articles/PMC3591834/
Shuhart CR, Yeap SS, Anderson PA, et al. Executive Summary of the 2019 ISCD Position Development Conference on Monitoring Treatment, DXA Cross-calibration and Least Significant Change, Spinal Cord Injury, Peri-prosthetic and Orthopedic Bone Health, Transgender Medicine, and Pediatrics. J Clin Densitom. 2019;22(4):453-471. https://pubmed.ncbi.nlm.nih.gov/31400968/
Osteoporosis. Radiopaedia.org. https://radiopaedia.org/articles/osteoporosis-3