MRI of the spine: image quality and normal-neoplastic bone marrow contrast at 3 T versus 1.5 T.
OBJECTIVE
The objectives of our study were to compare image quality of the spine and visualization of spine abnormalities at 3 T and 1.5 T as well as to evaluate differences in quantitative assessment of normal and neoplastic vertebral bone marrow.


METHODS
One hundred nine MR examinations of the spine were performed at 1.5 T and 3 T in the same patients within a time interval of less than 3 months. Visualization of anatomic and pathologic structures was analyzed by two radiologists. Normal and pathologic bone marrow was assessed on T1-weighted fast spin-echo (FSE) sequences. The signal intensity contrast of neoplastic bone marrow versus normal vertebral bone marrow was measured at 1.5 T versus 3 T. Sensitivity, specificity, and accuracy with 95% CIs were computed to assess the performance of muscle and disk as standards to differentiate between neoplastic and normal bone marrow on T1-weighted sequences at 1.5 T and 3 T.


RESULTS
For all anatomic structures evaluated, image quality was rated significantly higher at 3 T than at 1.5 T, with 71.6% of the studies overall being superior at 3 T. The contrast between normal and pathologic bone marrow was significantly larger at 3 T (mean +/- SD, 0.33 +/- 0.13) than at 1.5 T (0.27 +/- 0.11). The highest accuracy was found using muscle signal at 3 T to differentiate between normal and pathologic bone marrow.


CONCLUSIONS
The use of 3-T MRI improves visualization of anatomic structures in the spine over 1.5-T MRI. As an internal standard on T1-weighted FSE images, skeletal muscle can be used to differentiate between infiltrative and normal bone marrow with higher accuracy at 3 T than at 1.5 T.
Zhao
Jian
J
Department of Radiology, University of California, San Francisco, 400 Parnassus Ave., A-367, Box 0628, San Francisco, CA 94143-0628, USA.
Krug
Roland
R
Xu
Duan
D
Lu
Ying
Y
Link
Thomas M
TM
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016477:Artifacts; D001853:Bone Marrow / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D013122:Spinal Diseases / Q000175:diagnosis* / Q000473:pathology; D013131:Spine / Q000033:anatomy & histology*; D018709:Statistics, Nonparametric