0.05).Conclusion Negative peak of click sound-induced myogenic reflex potentials on masseter muscle could be of vestibular origin.We have established an ideal animal model of the acoustically evoked vestibulo-masseter reflex by using a metal clip to maintain masseter muscle tension between the jaw and skull.

OBJECTIVE: To analyze the MR imaging findins of acinic cell carcinoma(ACC) in parotid gland and develop the diagnosis of this disease. METHOD: The MR imaging fearures of 11 patients with pathologically proved ACC were retrospectively analyzed. MR imagings were analyzed in relation to the follow:amount, location, size, shape, margin, pseudocapsule, MR signal intensity and enhanced pattern and the cervical lymphadenopathy. The clinical analysis on patients included age, sex, and follow-up. RESULT: There were 11 patients, 7 lesions was located in the right parotid gland and 4 lesions was located in the left parotid gland; the average maximum diameter was (2.66±0.99)cm; 7 lesions showed lobulated,and 4 lesions showed round; 8 lesions had no pseudocapsules and 3 lesions had incomplete pseudocapsule. All lesions showed homogeneous or heterogeneous isointense and slight hyperintense on T1 WI and T2WI. On post contrast images, the tumor parenchyma ingredients showed remarkable enhancement in all lesions. CONCLUSION The MR imaging of ACC in the parotid gland don't have specific features, but when the tumor of the parotid gland showed no pseudocapsule (or showed incomplete pseudocapsule), lobulate, small cysitc and remarkable enhancement, it may indicate ACC, and the correct diagnosis depends on clinical pathology.
Carcinoma, Acinar Cell ; pathology ; Contrast Media ; Humans ; Magnetic Resonance Imaging ; Parotid Gland ; Retrospective Studies ; Salivary Gland Neoplasms ; pathology