MR淋巴造影术诊断肢体淋巴水肿

目的 探讨新的能够反映形态学和功能改变的淋巴循环系统疾病的影像诊断方法.方法 皮内注射钆贝葡胺注射液后采用Philip 3.0T MR成像仪进行扫描,观察淋巴结和淋巴管的形态改变和功能状况,包括淋巴液在管内的流速和腹股沟淋巴结内造影剂充盈的动态性改变.结果 30例门诊肢体淋巴水肿患者接受了检查,原发性下肢淋巴水肿27例,继发性淋巴水肿3例.注射造影剂后所有的患肢淋巴管均显影,原发性淋巴水肿肢体的淋巴管形态变异较大.测得的淋巴的流速为0.30～1.48 cm/min.患侧腹股沟淋巴结造影剂浓度显著低于健侧.造影剂在患侧淋巴结内达到峰值的时间和排除的时间均明显较健侧延迟.此外,患侧淋巴结内有造影剂部分充盈和髓质区先充盈等异常发现.结论 采用钆贝葡胺造影剂的MR淋巴造影是形态和功能兼备的肢体淋巴循环障碍疾病的检查方法.

Diagnosis of peripheral lymph circulation disorders with contrast MR lymphangiography

Objective To evaluate anatomical and functional images of contrast MR lymphangiography in the diagnosis of limb lymphatic circulation disorders. Methods 30 patients with limb lymphedema were enrolled in the study. There were 27 patients of primary lymphedema and 3 of secondary lymphedema. Contrast enhanced lymphangiography was performed with 3.0T MR Unit after intracutaneous injection of gadobenate dimelumine into the interdigital webs of the dorsal foot and hand. The kinetics of enhanced lymph flow within the lymphatics were calculated using the formula;Speed (cm) = total length of visualized lymph vessel ( cm) / inspection time ( minutes) and by comparing dynamic nodal enhancement and time-signal intensity curves between edematous and contralateral limbs. Morphological abnormalities of the lymphatic system were also evaluated. Results Following injection of the contrast agent enhanced lymphatic channels were consistently visualized in all clinical lymphedematous limbs and five contralateral limbs of unilateral lymphedema cases. The speed of enhanced flow within the lymphatics of lymphedematous limbs ranged from 0. 30 to 1. 48 cm/min. The contrast enhancement in inguinal nodes of edematous limbs was significantly lower than that of contralateral limbs ( P < 0. 01 ) . Dynamic measurement of contrast enhancement showed a remarkable lowering of peak time ( P < 0 .01 ) and peak enhancement (P < 0. 01 ) and a delay in outflow in inguinal nodes of affected limbs compared with that of control limbs. Post-contrast MR imaging also depicted varied distribution patterns of lymphatics and abnormal lymph flow pathways within lymph nodes in the limbs with lymphatic circulation disorders. Conclusions Contrast MR lymphangiography with gadobenate dimelumine was able to visualize the precise anatomy of lymphatic vessels and lymph nodes in lymphedematous limbs. It also provided comprehensive information about the functional status of lymph flow transportation in lymphatics and lymph nodes.