Validation of a CT-derived method for osteoporosis screening in IBD patients undergoing contrast-enhanced CT enterography.
OBJECTIVE
Osteoporosis and bone fractures are of particular concern in patients with inflammatory bowel disease (IBD). Biomechanical computed tomography (BCT) is an image-analysis technique that can measure bone strength and dual-energy X-ray absorptiometry (DXA)-equivalent bone mineral density (BMD) from noncontrast CT images. This study seeks to determine whether this advanced technology can be applied to patients with IBD undergoing CT enterography (CTE) with IV contrast.


METHODS
Patients with IBD who underwent a CTE and DXA scan between 2007 and 2011 were retrospectively identified. Femoral neck BMD (g/cm(2)) and T-scores were measured and compared between DXA and BCT analysis of the CTE images. Femoral strength (Newtons) was also determined from BCT analysis.


RESULTS
DXA- and CTE-generated BMD T-score values were highly correlated (R(2)=0.84, P<0.0001) in this patient cohort (n=136). CTE identified patients with both osteoporosis (sensitivity, 85.7%; 95% confidence interval (CI), 48.7-97.4 and specificity, 98.5%; 95% CI, 94.5-99.6) and osteopenia (sensitivity, 85.1%; 95% CI, 72.3-92.6 and specificity, 85.4%; 95% CI, 76.6-91.3). Of the 16 patients who had "fragile" bone strength by BCT (placing them at the equivalent high risk of fracture as for osteoporosis), 6 had osteoporosis and 10 had osteopenia by DXA.


CONCLUSIONS
CTE scans can provide hip BMD, T-scores, and clinical classifications that are comparable to those obtained from DXA; when combined with BCT analysis, CTE can identify a subset of patients with osteopenia who have clinically relevant fragile bone strength. This technique could markedly increase bone health assessments in IBD patients already undergoing CTE to evaluate small bowel disease.
Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
Nicholas K
NK
Weber
Department of Radiology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
Jeff L
JL
Fidler
1] O.N. Diagnostics, Berkeley, California, USA [2] Departments of Mechanical Engineering and Bioengineering, UC Berkeley, California, USA.
Tony M
TM
Keaveny
Division of Endocrinology, Diabetes, Metabolism and Nutrition, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
Bart L
BL
Clarke
Division of Endocrinology, Diabetes, Metabolism and Nutrition, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
Sundeep
S
Khosla
Department of Radiology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
Joel G
JG
Fletcher
O.N. Diagnostics, Berkeley, California, USA.
David C
DC
Lee
Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
Darrell S
DS
Pardi
Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
Edward V
EV
Loftus
Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
Sunanda V
SV
Kane
Department of Radiology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
John M
JM
Barlow
Department of Radiology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
Naveen S
NS
Murthy
Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
Brenda D
BD
Becker
Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
David H
DH
Bruining
D015502:Absorptiometry, Photon / Q000379:methods; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density; D003287:Contrast Media; D005260:Female; D005272:Femur Neck / Q000000981:diagnostic imaging; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000150:complications / Q000000981:diagnostic imaging*; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D008910:Minnesota; D010024:Osteoporosis / Q000150:complications / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult
D003287:Contrast Media