重T2WI和增强T1WI MRI联合评估泪囊鼻泪管的优势

发布时间：2018-06-09 01:19

本文选题：泪器 + 磁共振成像　；参考：《磁共振成像》2016年01期

【摘要】：目的探讨MRI重T2WI(h-T2WI)和增强T1WI(Ce-T1WI)组合序列对正常和阻塞的泪囊鼻泪管的显示能力。材料与方法在脂肪抑制的基础上,用hT2WI和Ce-T1WI序列,薄层连续扫描正常和有阻塞的泪囊鼻泪管,扫描方位是轴面(AP)和冠状面(CP),用静态和动态两种扫描方式。结果静态扫描正常泪囊鼻泪管23例46侧,其中24侧用h-T2WI+Ce-T1WI+AP+CP组合,6侧用hT 2 W I+C e-T 1 W I+A P组合,8侧用h-T 2 W I+A P+C P组合,8侧用C eT1WI+AP+CP组合。动态轴面扫描正常泪囊鼻泪管10例20侧,均用hT2WI+AP组合。静态扫描阻塞的泪囊鼻泪管9例10侧,均用h-T2WI+CeT1WI+AP+CP组合。正常和有阻塞的泪囊鼻泪管均能被良好显示。(1)正常的泪囊鼻泪管:静态扫描见泪囊鼻泪管的管腔狭小,鼻泪管更小,并且形态多样;动态扫描见部分节段的管腔可自主性增大或变小。横断面上泪囊呈长椭圆形(16侧)或裂隙状(30侧),移行部均呈半月形,鼻泪管呈短椭圆形(28侧)或类圆形(18侧)。用静态h-T2WI序列,轴面图像上94.7%(36/38侧)的泪囊鼻泪管呈现了3层信号结构,冠状面图上31.2%(10/32侧)呈现了3层信号结构;这3层信号结构分别代表了管腔内容物、管壁内1/4和管壁外3/4;管腔内的泪液、泪膜和空气分别呈最高信号、高信号和最低信号;管壁内1/4呈低信号,管壁外3/4呈高信号。在Ce-T1WI序列上,管壁可以被明显强化。(2)有阻塞的泪囊鼻泪管:梗阻部位和病变的范围均被精确显示,其中管腔狭窄1侧,闭塞9侧;梗阻点以上管腔积液(脓)扩张,管壁变薄;梗阻点管腔消失或明显狭小,在h-T2WI上丧失3层信号结构。结论 h-T2WI结合Ce-T1WI序列的MRI,可以清晰的显示正常生理状态下的泪囊鼻泪管的管腔、管壁的层次和行经;也能够精确显示有梗阻的泪囊鼻泪管的梗阻部位、病灶范围,区分有血供和无血供的组织结构。动态h-T2WI发现正常管腔的大小有自主性变化。
[Abstract]:Objective to investigate the display of normal and obstructed dacryocyst nasolacrimal duct by MRI combined with T2WI- T2WI and enhanced T1WI- Ce-T1WI. Materials and methods on the basis of fat suppression, the nasolacrimal duct with normal and obstructed dacryocyst was continuously scanned with hT2WI and Ce-T1WI sequences. Results the nasolacrimal duct of 23 patients with normal lacrimal sac was statically scanned in 46 sides, of which 24 sides were treated with h-T2WI Ce-T1WI AP CP combination, 6 sides with HT2WI-Ce-T1WI AP CP combination, 8 sides with h-T 2WI A P P combination and 8 sides with CeT1WI AP CP combination. Dynamic axial scanning of normal dacryocyst nasolacrimal duct was performed in 10 cases (20 sides). The nasolacrimal duct obstructed by static scanning was performed in 9 cases (10 sides) with h-T _ 2WI CeT _ 1WI AP CP combination. Normal and obstructed dacryocyst nasolacrimal duct can be well displayed. 1) normal dacryocyst nasolacrimal duct: static scanning shows that the lacrimal duct of dacryocyst nasolacrimal duct is narrow, the nasolacrimal duct is smaller, and the shape of nasolacrimal duct is various. Dynamic scanning shows that the lumen of some segments can be increased or reduced autonomously. On the cross section, the lacrimal sac was long oval (16 sides) or fissure (30 sides), the transitional part was half moon shape, and the nasolacrimal duct was short oval shape (28 sides) or 18 sides of round canal. The nasolacrimal duct in the dacryocyst nasolacrimal duct on the axial image of 94.775 / 36 / 38 sides presented three layers of signal structure, and the coronal image of 31.22T / 10 / 32 sides of the dacryocyst nasolacrimal duct presented a 3-layer signal structure, which represented the contents of the tube cavity. The tear, tear film and air in the tube wall showed the highest signal, high signal and the lowest signal, respectively, and a quarter of the tube wall showed low signal, and the third fourth signal was high signal outside the tube wall, respectively, in the tube wall 1 / 4 and outside the tube wall, the tear film and air showed the highest signal, the high signal and the lowest signal, respectively. On Ce-T1WI sequence, the obstruction of dacryocyst nasolacrimal duct could be obviously enhanced. The lumen of obstruction point disappeared or was obviously narrow, and three layers of signal structure were lost on h-T 2 WI. Conclusion h-T2WI combined with MRI sequence of Ce-T1WI can clearly display the lumen and wall of dacryocyst nasolacrimal duct in normal physiological condition, and can also accurately display the obstruction site and lesion range of dacryocyst nasolacrimal duct with obstruction. The tissue structure that distinguishes between blood supply and no blood supply. Dynamic h-T 2 WI showed that the size of the normal lumen had independent changes.
【作者单位】：广东省中西医结合医院放射科;广东省中西医结合医院眼科;
【分类号】：R445.2;R777.23

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