The value of chemical fat-saturation pulse added to T1-weighted spin-echo sequence in evaluating gadolinium-enhancing brain lesions in multiple sclerosis.
OBJECTIVE
This study was undertaken to assess the value of a chemical (spectral) fat-saturation (fat-sat) pulse added to a T1-weighted spin-echo sequence after intravenous administration of paramagnetic contrast agent in detecting enhancing lesions in multiple sclerosis.


METHODS
Twenty patients with relapsing-remitting multiple sclerosis underwent a brain 1.0-Tesla magnetic resonance (MR) scan with T1-weighted spin-echo sequences (24 contiguous para-axial slices with a thickness of 5 mm, pixel size 0.96 mm(2), number of excitations 2, flip angle 90 degrees ) 5 min after intravenous injection of 0.1 mmol/kg of gadodiamide with and without fat-sat, acquired with randomised order of priority. Two readers counted by consensus the number of enhancing lesions and assigned a conspicuity score (low conspicuity=1; high conspicuity=2) to each enhancing lesion during a randomised reading without any visual comparison between the two corresponding images (with and without fat-sat) of the same patient. McNemar and Wilcoxon matched-pair signed-rank tests were used.


RESULTS
Seventy-two enhancing lesions without fat-sat and 94 with fat-sat were detected; 22 lesions were visible only with fat-sat, whereas no lesion was detected only without fat-sat (p<0.0001). The conspicuity score was 1.17+/-0.38 (mean+/-standard deviation) and 1.57+/-0.44, respectively (p<0.0001).


CONCLUSIONS
A fat-sat pulse added to a T1-weighted spin-echo sequence increases significantly the number and conspicuity of contrast-enhancing lesions in patients with relapsing-remitting multiple sclerosis.
Sardanelli
F
F
Department of Medical and Surgical Sciences, Radiology Unit, IRCCS Policlinico San Donato, University of Milan School of Medicine, Via Morandi 30, San Donato Milanese, Milan, Italy. francesco.sardanelli@unimi.it
Schiavoni
S
S
Iozzelli
A
A
Fausto
A
A
Aliprandi
A
A
Mancardi
G L
GL
Filippi
M
M
D000328:Adult; D001921:Brain / Q000473:pathology*; D003287:Contrast Media / Q000008:administration & dosage; D005260:Female; D019786:Gadolinium DTPA / Q000008:administration & dosage; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000473:pathology*; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric
D003287:Contrast Media; C064925:gadodiamide; D019786:Gadolinium DTPA