动态增强MR成像在不典型肺结核球中的应用

Usefulness of dynamic contrast MR in the evaluation of atypical lung tuberculoma

目的:探讨动态增强MRI在不典型肺结核球诊断与鉴别诊断中的应用价值。方法:经手术与临床证实的10例不典型肺结核球患者进行DCE-MRI成像,常规进行T1WI、T2WI和DCE-MRI成像,DCE-MRI采用3D-LAVA技术,总共采集18个时相,每个时相扫描时间控制在5～7s,于注药后10、50s分别进行两次连续扫描,后间隔30s扫描直至4min,而后间隔1min扫描直至12min。图像分析时将ROI曲线放置在肿瘤最大层面。按照Schaefer的标准将时间信号强度曲线划分为A～D4种类型,描述不典型肺结核球的曲线类型及信号特点。结果:肺结核球T1WI中8例呈稍低信号,2例呈稍高信号,SI值﹥250。MR增强表现三种曲线形式,A型1例;环形强化7例(周边环呈A型,中央区域呈D型);D型2例。环形强化病例双曲线形式,强化环基本完整,2例T2WI即呈双环信号改变。D型病例T2WI呈等低信号。结论:肺MR成像有助于不典型肺结核球的诊断与鉴别诊断,且可能提示肺结核球的演变过程:A型-环形强化-D型。环形强化和D型肺结核球易于作出正确诊断。A型曲线与周围型肺癌相近,抗炎或抗结核后随诊至关重要。

Objective To investigate the value of dynamic contrast-enhanced MRI for evaluating diagnosis and differential diagnosis of atypical lung tuberculoma. Methods Ten consecutive patients enrolled in this study, all of whom underwent T1WI, T2WI, DCE-MRI examinations and received a histologic and clinical diagnosis. DCE- MRI was acquired with 3D LAVA technique, total 18 phases were acquired, scanner time of per phase was 5 - 7 s. After contrasting agent, twice successNe scanning was acquired at 10 s and 50 s. Then 1 min 30 s, 2 min, 2 rain 30s, 3 min, 3 min 30s, 4 min, 5 rain, 6 min, 7 min, 8 rain, 9 rain, I0 min, II rain, 12 min performed scanning. Region of interest was placed on the Maximum level in the tumors. According to Schaefer＇s standard, four types of time signal intensity curve （TIC） were classified, which were A, B, C and D. Compared the dynamic parameters between benign and malignant nodules. Results Eight cases with Lung tuberculoma exhibited hypo- intensity on T1WI, 2 cases hyper-intensity and SI value exceeded 250. Lung tuberculoma may display three MR enhancement curves： A type 1 case, ring-shaped enhancement 7 cases （periphery ring A type, central region D type）, D type 2 cases. Ring-shaped enhancement 7 cases exhibited hypcrbola mode and its enhancement ring was completely, among these, 2 cases exhibited double ring on T2WI. Low signal on T2WI was seen in D type cases. Conclusion Lung MR imaging is helpful to diagnosis and differential diagnosis of atypical lung tuberculoma. The evolution of global tuberculosis may be from A type to ring-shaped ennoblement to D type. It was easy to do right diagnosis to lung tuberculoma with ring-shaped enhancement and D type. It is important to anti-inflammatory or anti- TB follow-up for a few A type nodules except for peripheral lung cancer.