T1-RHO DISPERSION IMAGING OF HEAD AND NECK TUMORS - A COMPARISON TO SPIN LOCK AND MAGNETIZATION-TRANSFER TECHNIQUES

The potential of T1(p) dispersion, spin lock (SL), and magnetization t ransfer (MT) techniques to differentiate benign and malignant head and neck tumors was evaluated. Twenty-four patients with pathologically v erified head and neck tumors were studied with a .1-T MR imager, T1(p) dispersion effect was defined as 1 - (intensity with lower locking fi eld amplitude/intensity with higher locking held amplitude). T1(p) dis persion effects were higher for malignant than benign tumors (P = .001 ), With T1(p) dispersion effect .14 as the threshold, sensitivity for detecting a malignant tumor was 91%, specificity was 77%, and accuracy was 83%. A strong correlation between T1(p) dispersion effects and SL effects and between T1(p) dispersion effects and MT effects in the he ad and neck tumors was found (r = .87, P < .001 and r = .90, P < .001, respectively), High T1(p) dispersion effects are not specific indicat ors of malignancy, because chronic infections, some benign tumors, and malignancies may overlap, Low T1(p) dispersion effect values are char acteristic of a benign tumor.