Conspicuity of tumors of the head and neck on fat-suppressed MR images: T2-weighted fast-spin-echo versus contrast-enhanced T1-weighted conventional spin-echo sequences.
OBJECTIVE
The purpose of this study was to compare the conspicuity of tumors of the head and neck on MR images acquired with T2-weighted fat-suppressed fast-spin-echo and contrast-enhanced T1-weighted fat-suppressed conventional spin-echo sequences.


METHODS
The MR images of 29 patients with 36 pathologically proved tumors of the head and neck were retrospectively analyzed. The conspicuity of these tumors was assessed on the T2-weighted sequence (4700/108 [TR/TE]) and on the contrast-enhanced T1-weighted sequence (500/16) with a 1.5-T system. Qualitative tumor-to-background contrast was graded separately against background muscle, fat, and mucosa (0 = not visualized, 1 = poorly visualized, 2 = fairly well visualized, 3 = well visualized), and the best overall sequence was noted for each tumor. Quantitative tumor-to-background ratios were measured for 10 of the tumors by using the same background markers.


RESULTS
The mean overall qualitative tumor-to-background contrast grades for the T2-weighted sequence were tumor/muscle = 2.84, tumor/fat = 2.20, and tumor/mucosa = 1.23, and for the contrast-enhanced T1-weighted sequence, they were tumor/muscle = 2.02, tumor/fat = 1.58, and tumor/mucosa = 0.73. Overall, 86% of the tumors were better or equally well visualized on the T2-weighted images. The mean overall quantitative tumor-to-background ratios for the T2-weighted sequence were tumor/muscle = 7.93, tumor/fat = 3.34, and tumor/mucosa = 0.68, and for the contrast-enhanced T1-weighted sequence, they were tumor/muscle = 2.43, tumor/fat = 2.28, and tumor/mucosa = 0.85.


CONCLUSIONS
The T2-weighted fat-suppressed fast-spin-echo sequence offers better contrast between tumors and adjacent muscle, fat, and mucosa than does the contrast-enhanced T1-weighted fat-suppressed spin-echo sequence and thus improves overall tumor conspicuity. In addition, the T2-weighted sequence does not require IV contrast material and can be performed more rapidly than can the contrast-enhanced T1-weighted sequence. The contrast-enhanced T1-weighted sequence may offer complementary information on the precise characterization of complex tumors and on the potential determination of tumor extent.
Dubin
M D
MD
Long Beach Memorial MRI Center, CA 90806, USA.
Teresi
L M
LM
Bradley
W G
WG
Jordan
J E
JE
Pema
P J
PJ
Goergen
S K
SK
Tam
J K
JK
D000273:Adipose Tissue / Q000473:pathology; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006258:Head and Neck Neoplasms / Q000175:diagnosis*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009092:Mucous Membrane / Q000473:pathology; D018482:Muscle, Skeletal / Q000473:pathology; D015588:Observer Variation; D012189:Retrospective Studies
D014408:Biomarkers, Tumor