A Control Study Of The Magnetic Resonance Dacryocystography And CT Dacryocystography

Objective:To control and analysis magnetic resonance dacryocystography(MRD)and computed tomographic dacryocystography(CTD)in the lacrimal disease.Methods:There are 19 patients(38 eyes)who are suffering from epiphora during march to september in 2006.There are 22 unnormal eyes(57.89%),16 normal eyes(42.11%);there are 9 cases of men(47.37%),10 cases of women(52.63%);these patients are between 8 to65 years old,whose mean age is 39.37 years old;the courses of the disease are between 3months to 20 years.All of these patients underwent MRD and CTD.MRD is three-dimensional fast-recovery spin-echo(3D-FRFSE),FRFSE T2-weighted oblique coronal and axial images were obtained after MRD.The FS T2WI obtained were paocessed by multiplanar reconstruction and maximum intensity projection.CT is scaning thin layeraxial on the whole lacrimal duct aresas by using X-ray.These datas were put into the workstation and then doctors conducted coronal,sagittal and three-dimensional reconstruction throngh the organization of X-ray absorption coefficient of unit volume measurement,at the same time using multiplanar reconstruction(MPR),curved surface reconstruction(CPR).Two subtropical high and the above title image diagnosis doctors analysis all the MRD and CTD dates to evaluate the consistency and diversity between MRI and CT of lacrimal duct anatomy,the cause and parts of lacrimal duct obstruction,the degree of lacrimal duct stenosis.The largest lacrimal sac cross-sectional area,the nasolacrimal duct,the lumen and the mucous membrane of cross-sectional area were measured,by taking the independent sample t test to analysis these dates,p<0.05statistically significant.Results:MRD,CTD and lacrimal duct syringing in qualitative diagnosis of lacrimal duct obstructive disease with consistency.MRD and CTD can clearly determine the site of lacrimal duct obstruction,almost the same,and can clearly display of the lacrimal duct and the surrounding anatomical details of organizational structures.The biggest lacrimal sac cross-sectional area of the normal group in MRD was(16.14±1.53)mm~2,and in CTD was(8.70±1.00)mm~2;while the unnormal group in MRD was(26.77±5.45)mm~2,and in CTD was(17.81±3.55)mm~2.The lacrimal duct cross-sectional area of the normal group in MRD was(27.66±11.28)mm~2,and in CTD was(20.60±7.66)mm~2;while the unnormal group in MRD was(29.85±9.66)mm~2,and in CTD was(21.25±7.42)mm~2.The lumen cross-sectional area of the normal group in MRD was(5.74±5.72)mm~2,and in CTD was(5.29±5.17)mm~2;while the unormal group in MRD was(5.24±3.19)mm~2,and in CTD was(4.11±4.44)mm~2.The mucous cross-sectional area of the normal group in MRD was(21.93±8.66)mm~2,and in CTD was(15.92±5.21)mm~2;while the unormal group in MRD was(23.50±7.54)mm~2,and in CTD was(16.85±5.63)mm~2.The biggest lacrimal sac cross-sectional area increased,the lacrimal duct diameter enlarged,the lumen narrowed,the mucous membrane thickened in the unnormal group compared with the normal group.The difference is statistically significant.Conclusion:MRD and CTD both have diagnostic value of lacrimal duct obstructive diseases,and there were no significant difference on accuracy and the detection rate of lacrimal duct obstruction position.It can be applied to the lacrimal duct obstructive disease alone.But on the application of special cases,MRD is more valuable on lacrimal duct tumor diseases and functional tears spill diseases,while CTD is irreplaceable on traumatic lacrimal duct obstructive diseases.It’s necessary to choose both of them in order to understanding the development of diseases,making correct treatment and assessing the prognosis of diseases.