SPIN LOCK AND MAGNETIZATION-TRANSFER IMAGING OF HEAD AND NECK TUMORS

PURPOSE: To evaluate and compare the spin lock and magnetization trans fer techniques in the differentiation of benign and malignant head and neck tumors at magnetic resonance (MR) imaging. MATERIALS AND METHODS : Forty consecutive patients with histologically verified head and nec k tumors (20 malignant and 20 benign tumors, including five infections ) were studied with a 0.1-T MR unit. The spin lock and magnetization t ransfer effects were defined as 1 - (signal intensity with stronger pr eparation pulse/signal intensity with weaker preparation pulse). RESUL TS: A strong correlation between the spin lock and magnetization trans fer effects was found (r = .85, P < .001). With a spin lock effect of 0.48 and a magnetization transfer effect of 0.32 as the thresholds, se nsitivity for detecting a malignant tumor was 95% and 94%, respectivel y, and specificity was 60% and 65%. CONCLUSION: Low spin lock and magn etization transfer effects are characteristic of benign tumors. High s pin lock and magnetization transfer effects were associated with malig nancy, but there were overlapping values for salivary gland infections , some benign tumors, and malignancies. The spin lock technique seems to be an effective method for generating magnetization transfer-based contrast in the head and neck tumors.