体素内不相干运动扩散加权成像对肝脏良恶性肿瘤的诊断价值探讨

Evaluation of Intravoxel Incoherent Motion Diffusion-Weighted Imaging in Differentiating Benign from Malignant Hepatic Neoplasm

目的探讨体素内不相干运动(IVIM)扩散加权成像对肝脏良恶性肿瘤的诊断价值。方法对临床怀疑为肝占位患者63例进行磁共振常规平扫T1WI、T2WI、DWI(b=0、800 s/mm2),多b值DWI及动态增强扫描,多b值DWI选用9个b值(b=0,20,50,100,200,400,600,800,1200 s/mm2),其中经手术病理证实、符合临床诊断或经随访证实的肝脏肿瘤性病变52例(70个病灶),全部病变分为良性组、恶性组,良性组21例(32个病灶),恶性组31例(38个病灶)。多b值DWI通过AW 4.5工作站测量得到快速表观扩散系数值(Fast-ADC)、慢速表观扩散系数值(Slow-ADC),快速扩散所占比率(fraction of fast ADC,ffast),并比较这些参数在肝脏良恶性肿瘤性病变中诊断价值。本研究获得伦理委员会的批准,均与所有患者签署知情同意书。结果良性组、恶性组Fast-ADC分别为(68.64±19.00)×10-3mm2/s、(55.79±14.98)×10-3mm2/s,Slow-ADC分别为(1.88±0.43)×10-3mm2/s、(0.85±0.27)×10-3mm2/s,ffast分别为(29.75±16.42)%、(22.95±8.34)%,良性组Fast-ADC、Slow-ADC和ffast均大于恶性组,良、恶性组Slow-ADC、Fast-ADC差异有统计学意义(P均<0.05),两组间ffast无统计学意义。结论体素内不相干运动扩散加权成像参数Slow-ADC、Fast-ADC可提高肝脏肿瘤性病变的良恶性诊断及鉴别诊断的能力。

Objective To assess the value of intravoxel incoherent motion diffusion-weighted imaging in differentiating the benign hepatic neoplasm from malignant one. Methods A total of 63 patients with clinically-suspected space-occup- ying lesion in liver were enrolled in this study. Routine plain MR scanning, including T1WI, T2WI, DWI （b = 0, 800 s/ mm^2） , muhi-b value DWI （b = 0, 20, 50, 100, 200, 400, 600, 800 and 1200 s/mm^2） and dynamic contrast-enhanced scanning, were performed in all patients. The diagnosis in 52 patients （70 lesions in total） was confirmed by pathology. The patients were divided into benign group （n = 21, 32 lesions） and malignant group （n = 31, 38 lesions）. Fast-ADC, slow-ADC, fraction of fast ADC （FFADC） were measured by using MADC analysis software on a AW 4.5 workstation, and their values in diagnosing and differentiating the benign and malignant hepatic tumors were determined, and the results were compared between the two groups. The prospective study protocol was approved by the Institutional Review Board and written-informed consent was obtained from all patients prior to the examination. Results Fast-ADC values of the benign group and malignant group were （68.64 ± 19.00）×10^-3mm^2/s and （55.79 ± 14.98） ×10^-3mm^2/s respectively, while slow-ADC values of the benign group and malignant group were （ 1.88 ±0.43）×10^-3mm^2/s and （0.85 ±0.27） ×10^-3mm^2/s respectively. FFADC values of the benign group and malignant group were （29.75 ± 16.42 ） % and （ 22.95 ± 8.34） % respectively. Fast-ADC, slow-ADC and FFADC values of the benign group were higher than those of the malig- nant group. Significant differences in fast-ADC and slow-ADC values existed between the benign group and malignant group （P 〈 0.05 in both ）, although the difference in FFADC values was not statistically significant between the two groups.Conclusion As important parameters of intravoxel incoherent motion diffusion-weighted imaging, both fast-ADC and slow- ADC play an important role in distinguishing benign hepatic neoplasm from malignant one.