Abstract：Objective To study MRI signal characteristics and size change in hypertrophic olivary degeneration(HOD) and improve the diagnosis of this disease. Methods Twenty-seven patients with HOD secondary to pons or cerebellar lesions were studied retrospectively. There were 25 cases with primary lesions located in pons, including cavernomas(1 case), trauma(8 cases), hypertensive hemorrhage(14 cases), and infarction(2 cases). The other 2 cases were with primary cerebellar lesions including trauma(1 case) and hemorrhage(1 case). Plain MRI scans were performed for all cases with T1WI, T2WI, FLAIR, DWI sequence and 8 cases with SWI sequence additionally.MRI characteristics of HOD and the diameters of the affected olivary nucleus were observed. Results MRI scan revesled hyperophied olivary nucleus with increased T2WI signal, iso-or slightly high signal intensity on DWI, slightly high intensity on FLAIR, iso-or slightly low signal intensity on T1WI. The average transverse diameter of the olivary nucleus was(6.94?0.67)mm, the average anterior posterior diameter was(6.69?0.83)mm, the average vertical diameter was (16.95?1.20)mm, the average distance between anterior olivary nucleus margin and medulla anterior margin was(1.37?0.56)mm. Conclusions MRI can clearly demonstrate hypertrophic olivary degeneration, thus avoiding error or mistake.
2014, Vol. 25 
