The use of CT Hounsfield unit values to identify the undiagnosed spinal osteoporosis in patients with lumbar degenerative diseases
Our purpose was to use computed tomography (CT) Hounsfield unit (HU) values to identify the undiagnosed spinal osteoporosis in patients with lumbar degenerative diseases.
A total of 334 patients with lumbar degenerative diseases were retrospectively reviewed and divided into two groups according to the degree of lumbar degenerative changes in preoperative lumbar CT images. Patients who had at least three vertebrae with severe degeneration at L1–L4 were placed in the degenerative group, and others were placed in the control group. HU value of trabecular bone in middle axial CT image of vertebral body, T-score and bone mineral density (BMD) at L1–L4 and hips were measured. CT HU thresholds for osteoporosis were obtained from control group and then applied to identify undiagnosed spinal osteoporosis.
There were 182 patients in the degenerative group and 152 patients in the control group. CT HU value had a positive correlation with T-score and BMD of lumbar spine in both groups (P < 0.001), while the correlation coefficients at L1–L4 were higher in the control group (> 0.7) than in the degenerative group (< 0.7). T-score and BMD of lumbar spine were higher in the degenerative group (P < 0.05), while CT HU value, T-score and BMD of hips had no significant difference between two groups. According to the linear regression equations of vertebral T-score and CT HU value in the control group, the thresholds matching T-score of − 2.5 were 110, 100, 85 and 80HU for L1, L2, L3 and L4, respectively. Defining CT osteoporosis as L1 ≤ 110HU or L2 ≤ 100HU or L3 ≤ 85HU or L4 ≤ 80HU was 88.5% (69/78) specific and 60.8% (45/74) sensitive for distinguishing DXA osteoporosis of lumbar spine in the control group. The rate of undiagnosed spinal osteoporosis was higher in the degenerative group than in the control group according to CT HU thresholds (38.7% vs. 11.5%, P < 0.05).
Degenerative changes in the lumbar spine can increase BMD and T-score provided by lumbar DXA, leading to an underestimation of vertebral osteoporosis. Thresholds for osteoporosis based on CT HU values can be used as a complementary method to identify undiagnosed spinal osteoporosis in patients with lumbar degenerative diseases.
KeywordsLumbar degenerative disease Osteoporosis CT Hounsfield unit value Dual-energy X-ray absorptiometry
This study was funded by Capital’s Funds for Health Improvement and Research (2016-1-4096).
Compliance with ethical standards
Conflict of interest
The authors declared that they have no conflict of interest.
All data collection and analysis conducted in this study were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. For this type of study, formal consent is not required.
- 1.WHO Scientific Group on the Prevention and Management of Osteoporosis (2000: Geneva, Switzerland) (2003) Prevention and management of osteoporosis: report of a WHO scientific group. Geneva: World Health Organization. http://apps.who.int/iris/bitstream/handle/10665/42841/WHO_TRS_921.pdf?sequence=1&isAllowed=y&ua=1
- 5.Pappou IP, Girardi FP, Sandhu HS, Parvataneni HK, Cammisa FP Jr, Schneider R, Frelinghuysen P, Lane JM (2006) Discordantly high spinal bone mineral density values in patients with adult lumbar scoliosis. Spine (Phila Pa 1976) 31(14):1614–1620. https://doi.org/10.1097/01.brs.0000222030.32171.5f CrossRefGoogle Scholar
- 10.Pickhardt PJ, Pooler BD, Lauder T, del Rio AM, Bruce RJ, Binkley N (2013) Opportunistic screening for osteoporosis using abdominal computed tomography scans obtained for other indications. Ann Intern Med 158(8):588–595. https://doi.org/10.7326/0003-4819-158-8-201304160-00003 CrossRefPubMedPubMedCentralGoogle Scholar
- 11.Pickhardt PJ, Lauder T, Pooler BD, Muñoz Del Rio A, Rosas H, Bruce RJ, Binkley N (2016) Effect of IV contrast on lumbar trabecular attenuation at routine abdominal CT: correlation with DXA and implications for opportunistic osteoporosis screening. Osteoporos Int 27(1):147–152. https://doi.org/10.1007/s00198-015-3224-9 CrossRefPubMedGoogle Scholar
- 13.Pompe E, de Jong PA, de Jong WU, Takx RA, Eikendal AL, Willemink MJ, Oudkerk M, Budde RP, Lammers JW, Mohamed Hoesein FA (2016) Inter-observer and inter-examination variability of manual vertebral bone attenuation measurements on computed tomography. Eur Radiol 26(9):1–8. https://doi.org/10.1007/s00330-015-4145-x CrossRefGoogle Scholar
- 17.Kim JY, Ryu DS, Paik HK, Ahn SS, Kang MS, Kim KH, Park JY, Chin DK, Kim KS, Cho YE, Kuh SU (2016) Paraspinal muscle, facet joint, and disc problems: risk factors for adjacent segment degeneration after lumbar fusion. Spine J 16(7):867–875. https://doi.org/10.1016/j.spinee.2016.03.010 CrossRefPubMedGoogle Scholar
- 20.Arabi A, Baddoura R, Awada H, Khoury N, Haddad S, Ayoub G, El-Hajj Fuleihan G (2007) Discriminative ability of dual-energy x-ray absorptiometry site selection in identifying patients with osteoporotic fractures. Bone 40(4):1060–1065. https://doi.org/10.1016/j.bone.2006.11.017 CrossRefPubMedGoogle Scholar
- 21.Engelke K, Adams JE, Armbrecht G, Augat P, Bogado CE, Bouxsein ML, Felsenberg D, Ito M, Prevrhal S, Hans DB, Lewiecki EM (2008) Clinical use of quantitative computed tomography and peripheral quantitative computed tomography in the management of osteoporosis in adults: the 2007 ISCD official positions. J Clin Densitom 11(1):123–162. https://doi.org/10.1016/j.jocd.2007.12.010 CrossRefPubMedPubMedCentralGoogle Scholar
- 23.Choi MK, Kim SM, Lim JK (2016) Diagnostic efficacy of Hounsfield units in spine CT for the assessment of real bone mineral density of degenerative spine: correlation study between T-scores determined by DEXA scan and Hounsfield units from CT. Acta Neurochir (Wien) 158(7):1421–1427. https://doi.org/10.1007/s00701-016-2821-5 CrossRefGoogle Scholar