[Diffusion-weighted imaging of acute vertebral compression: Differential diagnosis of benign versus malignant pathologic fractures].
OBJECTIVE
Our purpose was to assess the value of diffusion-weighted steady-state free precession (SSFP) sequence for differentiating between benign and pathologic compression fractures.


METHODS
Forty-nine patients with 63 acute vertebral compression fractures caused by osteoporosis (n = 23), trauma (n = 7), malignancy (n = 30), infection (n = 3) were examined with a diffusion-weighted SSFP sequence (diffusion gradient strength; 23 mT/m, diffusion pulse length 5 ms), T1-weighted turbo spin-echo sequence, and short-inversion-time (TI 150 ms) T2-weighted turbo inversion recovery sequence. The signal intensity characteristics were analyzed qualitatively and quantitatively for all sequences. Statistical analysis was performed with the Student's t test.


RESULTS
In diffusion-weighted MR imaging, benign osteoporotic and traumatic fractures were hypo- to isointense to adjacent normal vertebral bodies. Pathologic and infectious compression fractures were hyperintense to normal vertebral bodies. Pathologic vertebral fractures had positive bone marrow contrast ratios at diffusion-weighted imaging, whereas non infectious benign vertebral fractures had negative values (p < 0.001). The difference in bone marrow contrast ratios for benign and pathologic compression fractures at T1-weighted TSE and T2-weighted turbo IR was not significant (p > 0.01).


CONCLUSIONS
Diffusion-weighted SSFP sequence provides unique information that significantly impacts the accuracy of radiologic diagnosis. Diffusion-weighted SSFP sequence may allow the differentiation of acute benign osteoporotic fractures from malignant compression fractures. Acute benign osteoporotic or traumatic fractures show hypointense or isointense signal on diffusion-weighted sequences that reflects persistent free water proton mobility. Malignant compression fractures show hyperintensity compared with normal surrounding bone marrow probably due to altered water proton mobility within the neoplasm.
Abanoz
Recep
R
Uludağ Universitesi Tip Fakültesi, Radyoloji Anabilim Dali, Ankara.
Hakyemez
Bahattin
B
Parlak
Müfit
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001853:Bone Marrow / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D005598:Fractures, Spontaneous / Q000473:pathology; D006801:Humans; D015601:Injury Severity Score; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012720:Severity of Illness Index; D016103:Spinal Fractures / Q000473:pathology*