Liver Cirrhosis: Intravoxel Incoherent Motion MR Imaging-Pilot Study
Liver Cirrhosis: Intravoxel Incoherent Motion MR Imaging-Pilot Study
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DOI：
10.1148/radiol.2493080080
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发表时间：
2008-12-01
期刊：
影响因子：
19.7
通讯作者：
Rahmouni, Alain
中科院分区：
文献类型：
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作者：
Luciani, Alain;Vignaud, Alexandre;Rahmouni, Alain
目的：回顾性评价呼吸触发的弥散加权（DW）磁共振（MR）成像序列，结合平行采集，基于体素内非相干运动（IVIM）理论计算纯分子(D)和灌注相关（D*, f）弥散参数，以确定这些参数在肝硬化患者和非肝纤维化患者之间是否存在差异。材料和方法：机构审查委员会批准了这项回顾性研究；知情同意被放弃。对3种烷烃幻影进行IVIM DW成像，并在其上对数绘制按b因子的信号强度衰减曲线。患者采用10个因子（0、10、20、30、50、80、100、200、400、800 sec/mm(2)）。纳入有肝硬化记录的患者（肝硬化组，n = 12）和无慢性肝病的患者（健康肝脏组，n = 25）。测量肝脏平均D、D*和f值，并与使用4个b值（0、200、400、800 sec/mm2）计算的表观扩散系数（ADC）进行比较。比较肝硬化组与健康肝组的肝脏ADC及D、f、D*参数。均数比较采用Student t检验。结果：幻像的信号强度衰减曲线呈单指数，患者呈双指数。在体内，健康肝脏组的平均ADC值显著高于D (ADC = 1.39 x 10(-3) mm(2)/sec +/- 0.2[标准差]vs D = 1.10 x 10（-3) mm(2)/sec +/- 0.7）和肝硬化组(ADC = 1.23 x 10(-3) mm(2)/sec +/- 0.4 vs D = 1.19 x 10(-3) mm(2)/sec +/- 0.5) （P = 0.03）。与健康肝组相比，肝硬化组ADC和D*显著降低(P值分别为。03和0.008)。结论：肝硬化患者弥散受限可能与D*变化有关，D*变化反映了肝硬化肝脏灌注减少，以及纯分子水弥散改变。(c) rsna， 2008年
Purpose: To retrospectively evaluate a respiratory-triggered diffusion-weighted (DW) magnetic resonance (MR) imaging sequence combined with parallel acquisition to allow the calculation of pure molecular-based (D) and perfusion-related (D*, f) diffusion parameters, on the basis of the intravoxel incoherent motion (IVIM) theory, to determine if these parameters differ between patients with cirrhosis and patients without liver fibrosis.Materials and Methods: The institutional review board approved this retrospective study; informed consent was waived. IVIM DW imaging was tested on three alkane phantoms, on which the signal-intensity decay curves according to b factors were logarithmically plotted. Ten b factors (0, 10, 20, 30, 50, 80, 100, 200, 400, 800 sec/mm(2)) were used in patients. Patients with documented liver cirrhosis (cirrhotic liver group, n = 12) and patients without chronic liver disease (healthy liver group, n = 25) were included. The mean liver D, D*, and f values were measured and compared with the apparent diffusion coefficient (ADC) computed by using four b values (0, 200, 400, 800 sec/mm2). Liver ADC and D, f, and D* parameters were compared between the cirrhotic liver group and healthy liver group. Means were compared by using the Student t test.Results: Signal-intensity decay curves were monoexponential on phantoms and biexponential in patients. In vivo, mean ADC values were significantly higher than D in the healthy liver group (ADC = 1.39 x 10(-3) mm(2)/sec +/- 0.2 [standard deviation] vs D = 1.10 x 10(-3) mm2/sec +/- 0.7) and in the cirrhotic liver group (ADC = 1.23 x 10(-3) mm(2)/sec +/- 0.4 vs D = 1.19 x 10(-3) mm(2)/sec +/- 0.5) (P = .03). ADC and D* were significantly reduced in the cirrhotic liver group compared with those in the healthy liver group (respective P values of .03 and .008).Conclusion: Restricted diffusion observed in patients with cirrhosis may be related to D* variations, which reflect decreased perfusion, as well as alterations in pure molecular water diffusion in cirrhotic livers. (C) RSNA, 2008