Osteoporosis CT
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American Roentgen Ray Society Images of Osteoporosis CT |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Eiman Ghaffarpasand, M.D. [2]
Overview
Bone CT scan may be helpful in the diagnosis of osteoporosis. The main finding on CT scan suggestive of osteoporosis is decreased bone mineral density (BMD). In order to describe the bone strength more precisely, it is necessary to do quantitative assays such as dual energy X-ray absorptiometry (DXA) and CT scan (especially volumetric quantitative CT (vQCT)). Modalities for assessing osteoporotic fracture risk, without any destruction or invasion, include high-resolution CT (hrCT) and micro CT (μCT). The only tests that are possible in vivo are hrCT and vQCT.
CT scan
Bone CT scan may be helpful in the diagnosis of osteoporosis. The main finding on CT scan suggestive of osteoporosis is decreased bone mineral density (BMD). Despite that bone mineral density (BMD) measurement may provide so much information about osteoporosis and also osteoporotic fracture risk, but some researchers suggest that it has a limited role in bone strength description. In order to describe the bone strength more precisely, it is necessary to do quantitative assays such as dual energy X-ray absorptiometry (DXA) and CT scan (especially volumetric quantitative CT (vQCT)).
Modalities for assessing osteoporotic fracture risk, without any destruction or invasion, include high-resolution CT (hrCT) and micro CT (μCT).
The only tests that are possible in vivo are hrCT and vQCT.[1]
Volumetric quantitative CT scan (vQCT)
Volumetric quantitative CT scan (vQCT) is a kind of CT scan, presenting precise trabecular BMD in single transverse CT slices. It is only used for lumbar spine and mid forearm.[2]
Advantages
- Very high precision; 1-2% of fault for BMD in radius, hip, and spine
- Very instant availability; seconds to minutes
- High accessibility throughout the world
- Least operator dependence (vs. ultrasonography)
Disadvantage
High-resolution CT scan (hrCT)
- High-resolution CT scanners (hrCTs) provide higher precision and thinner slices which better distinguish trabecular and cortical bones.
- This leads to better estimation of fragility fractures.
- Trabecular bone density measurement is done indirectly through some other descriptors, such as texture or statistics.[1]
- Trabecular bone measurement using hrCT is more effective than BMD measurement using DXA.[3]
Micro CT scan (μCT)
- The micro CT (μCT) has the resolution of 1-100μm, using synchrotron radiation.
- It helps to replace the need for multiple staining and histomorphometric analyses.
- μCT is more used in laboratory animals for research purposes due to difficulty with sample collection.
The comparison between three different modalities[1]
| vQCT | hrCT | μCT | |
|---|---|---|---|
| Site of study | Vertebrae, hip, forearm, and tibia | Vertebrae and forearm | Human biopsies: Iliac crest
Animals and specimen: Various |
| Samples | Human in vivo | Human in vivo/human biopsies/bone specimen | Laboratory animals in vivo and in vitro/ bone specimen |
| Applications | BMD/bone macrostructure/FEM | Bone macrostructure/trabecular microstructure | Trabecular and cortical microstructure/μFEM |
References
- ↑ 1.0 1.1 1.2 1.3 Genant HK, Engelke K, Prevrhal S (2008). "Advanced CT bone imaging in osteoporosis". Rheumatology (Oxford). 47 Suppl 4: iv9–16. doi:10.1093/rheumatology/ken180. PMC 2427166. PMID 18556648.
- ↑ Lang TF, Guglielmi G, van Kuijk C, De Serio A, Cammisa M, Genant HK (2002). "Measurement of bone mineral density at the spine and proximal femur by volumetric quantitative computed tomography and dual-energy X-ray absorptiometry in elderly women with and without vertebral fractures". Bone. 30 (1): 247–50. PMID 11792593.
- ↑ Ito M, Ikeda K, Nishiguchi M, Shindo H, Uetani M, Hosoi T, Orimo H (2005). "Multi-detector row CT imaging of vertebral microstructure for evaluation of fracture risk". J. Bone Miner. Res. 20 (10): 1828–36. doi:10.1359/JBMR.050610. PMID 16160740.