MAGNETIZATION-TRANSFER CONTRAST MR IN LESIONS OF THE HEAD AND NECK

PURPOSE: To compare lesion-to-background contrast with and without mag netization transfer (MT) in lesions of the head and neck. METHODS: Twe nty lesions (16 malignant, 4 benign) were evaluated in 17 patients (11 men, 6 women; mean age, 58 years; age range, 39-76 years). In 13 pati ents, MR imaging was performed at 0.1 T with continuous-wave, off-reso nance MT; in 4 patients. MR imaging was performed at 1.5 T with on-res onance, binomial MT prepulses. Fifteen sequences were conducted before the administration of gadopentetate dimeglumine; 13 were conducted af ter the administration of that contrast material. The ratio of signal intensity with the MT pulses (Ms) to signal intensity without the MT p ulses (Mo) was calculated, as were the lesion-to-background contrast a nd the contrast-to-noise ratios. RESULTS: Ms/Mo showed both wide varia bility and considerable overlap among different lesion types. Images f rom MT sequences showed better contrast than those from non-MT sequenc es in 23 of 28 lesions (12 of 15 before and 11 of 13 after the adminis tration of contrast material). The mean contrast improvement percentag es (+/- standard deviation) were 165.5% (+/-58%) on unenhanced images and 186.6% (+/-84.8%) on contrast-enhanced images. The mean improvemen ts in contrast-to-noise ratios were 156% (+/-60%) on unenhanced images and 171.6% (+/-98.1%) on contrast-enhanced images. CONCLUSION: MT imp roved contrast between nodes or tumors showing an MT effect and backgr ound tissue (usually fat) not showing an MT effect. MT also improved c ontrast between contrast-enhanced neoplastic lesions and background ti ssue that showed an MT effect.