Comparing T1-weighted and T2-weighted three-point Dixon technique with conventional T1-weighted fat-saturation and short-tau inversion recovery (STIR) techniques for the study of the lumbar spine in a short-bore MRI machine.
OBJECTIVE
To compare T1-weighted (W) fat-water separation (Dixon's technique) with T1W fat-saturation (FS) and T2W Dixon with short-tau inversion recovery (STIR) images for fat suppression in a short-bore MRI machine.


METHODS
Thirteen patients with lumbar disease were studied on using 1.5 T MRI machine. The protocol included T1 FS (with contrast medium administration) and/or STIR and T1W and/or T2W Dixon, for comparison. Three neuroradiologists scored the images from the two-pairs of techniques for fat suppression uniformity and lesion conspicuity. Clinical usefulness of fat-only images was also evaluated.


RESULTS
Regarding uniformity of fat suppression, mean scores were 2.28 (±0.49), 3.06 (±0.49), 2.39 (±0.49), and 3.15 (±0.35) for T1W FS, T1W Dixon, STIR, and T2W Dixon sequences, respectively. For the same pulse sequences, lesion conspicuity scores were 2.78 (±0.50), 2.78 (±0.27), 2.76 (±0.47), and 2.91 (±0.4), respectively. Both T1W and T2W Dixon sequences showed more homogeneous fat-suppression when compared to T1W FS (p = 0.026) and STIR (p = 0.008) techniques, but no significant difference was found for lesion conspicuity. Mean scores for the diagnostic utility of fat-only maps were, respectively, 1.72 (±0.39) and 2.48 (±0.50) for T1W and T2W Dixon.


CONCLUSIONS
Fat suppression quality was superior with Dixon when compared to the conventional sequences, but not lesion conspicuity, suggesting that both techniques are reliable for diagnosis. Dixon may be advantageous in cases where inhomogeneity artefacts are an issue. Water-only maps appear to be useful in the clinical setting.
Clínica Médica Arrifana de Sousa, Penafiel, Portugal. Electronic address: sofia.brand@gmail.com.
S
S
Brandão
D
D
Seixas
M
M
Ayres-Basto
S
S
Castro
J
J
Neto
C
C
Martins
J C
JC
Ferreira
F
F
Parada
D000328:Adult; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D005682:Gadolinium; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007091:Image Processing, Computer-Assisted / Q000379:methods; D055959:Intervertebral Disc Degeneration / Q000175:diagnosis*; D007405:Intervertebral Disc Displacement / Q000175:diagnosis*; D008159:Lumbar Vertebrae / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011446:Prospective Studies; D015203:Reproducibility of Results; D055815:Young Adult
D003287:Contrast Media; D005682:Gadolinium