Distal radius in adolescent girls with anorexia nervosa: trabecular structure analysis with high-resolution flat-panel volume CT.
OBJECTIVE
To examine trabecular microarchitecture with high-resolution flat-panel volume computed tomography (CT) and bone mineral density (BMD) with dual-energy x-ray absorptiometry (DXA) in adolescent girls with anorexia nervosa (AN) and to compare these results with those in normal-weight control subjects.


METHODS
The study was approved by the institutional review board and complied with HIPAA guidelines. Informed consent was obtained. Twenty adolescent girls, 10 with mild AN (mean age, 15.9 years; range, 13-18 years) and 10 age- and sex-matched normal-weight control subjects (mean age, 15.9 years; range, 12-18 years) underwent flat-panel volume CT of distal radius to determine apparent trabecular bone volume fraction (BV/TV), apparent trabecular number (TbN), apparent trabecular thickness (TbTh), and apparent trabecular separation (TbSp). All subjects underwent DXA of spine, hip, and whole body to determine BMD and body composition. The means and standard deviations (SDs) of structure parameters were calculated for AN and control groups. Groups were compared (Student t test). Linear regression analysis was performed.


RESULTS
AN subjects compared with control subjects, respectively, showed significantly lower mean values for BV/TV (0.37% +/- 0.05 [SD] vs 0.46% +/- 0.03, P = .0002) and TbTh (0.31 mm +/- 0.03 vs 0.39 mm +/- 0.03, P < .0001) and higher mean values for TbSp (0.54 mm +/- 0.13 vs 0.44 mm +/- 0.04, P = .02). TbN was lower in AN subjects than in control subjects, but the difference was not significant (1.17 mm(-3) +/- 0.15 vs 1.22 mm(-3) +/- 0.07, P = .43). There was no significant difference in BMD between AN and control subjects. BMD parameters showed positive correlation with BV/TV and TbTh in the control group (r = 0.55-0.84, P = .05-.01) but not in AN patients.


CONCLUSIONS
Flat-panel volume CT is effective in evaluation of trabecular structure in adolescent girls with AN and demonstrates that bone structure is abnormal in these patients compared with that in normal-weight control subjects despite normal BMD.


BACKGROUND
http://radiology.rsnajnls.org/cgi/content/full/249/3/938/DC1.
Bredella
Miriam A
MA
Department of Radiology, Massachusetts General Hospital, 55 Fruit St, Yawkey 6E, Boston, MA 02114, USA. mbredella@partners.org
Misra
Madhusmita
M
Miller
Karen K
KK
Madisch
Ijad
I
Sarwar
Ammar
A
Cheung
Arnold
A
Klibanski
Anne
A
Gupta
Rajiv
R
D015502:Absorptiometry, Photon; D000293:Adolescent; D000856:Anorexia Nervosa / Q000000981:diagnostic imaging*; D001823:Body Composition; D015519:Bone Density; D005260:Female; D006801:Humans; D011884:Radius / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000295:instrumentation*