Application Of MRI In The Study Of Congenital Superior Oblique Paralysis

Objective The purpose of this experiment is to investigate themaximum cross-section area and volume of superior oblique muscles innormal volunteers and patients with congenital superior obliqueparalysis(SOP) and probe the pathological change of congenital superioroblique paralysis(congenital SOP).Mehods Fifteen patients (seventeen eyes) with congenital SOPformed patient group and ten health volunteers (ten eyes) formed normalcontrol group, scanning the superior oblique muscles of patient and normalcontrol groups with MRI on coronary and axial surface. Maximumcross-section area and volume of superior oblique muscles were measuredand compared using MRI with the surface coil, computer image processingand three-dimensional measuring technique in 10 volunteers and 15 patientswith congenital SOP. Using SPSS software package to finish the statisticalanalysis.Results(1)The size of superior oblique in patients with congenital SOP wasshrunk on MRI.(2)The mean maximal cross-section area and mean volume of superior oblique were (18.90±1.46)mm~2 and (256.05±21.92)mm~3 in normalcontrol group respectively and were (14.83±3.55)mm~2 and (188.89±57.03)mm~3 in the congenital SOP group. (p＜0.05)(3)No significant correlation was found between maximal cross-sectionarea,volume of superior oblique and aging in the congenital SOP group.(4)The lowerlimit of 95% confidence interval of mean volume ofsuperior oblique were 240.37mm~3 in normal control group respectively. Involume of superior oblique of congenital SOP, 12 examples (70.59%) werelower than the lowerlimit and 5 examples (29.41%) were higher than thelowerlimit.Conclusion The size of superior oblique in patients with congenitalSOP was shnmk on MRI. In the patients with congenital SOP, there may bevarious anatomic abnormalities, including superior oblique muscles, thesuperior oblique tendons and the pulleys of extra-ocular muscles.