Erturk Sukru Mehmet, Ichikawa Tomoaki, Sano Katsuhiro, Motosugi Utarou, Sou Hironobu, Araki Tsutomu
Department of Radiology, Sisli Etfal Hospital, Istanbul, Turkey.
J Comput Assist Tomogr. 2008 Nov-Dec;32(6):865-71. doi: 10.1097/RCT.0b013e3181591cf2.
To evaluate the impact of parallel imaging (sensitivity encoding [SENSE] technique) on diffusion-weighted (DW) magnetic resonance imaging, compare DW imaging techniques with 2 different b values for characterization of focal hepatic lesions, and determine apparent diffusion coefficient cutoff values.
Seventy-eight patients with 86 lesions were examined with 4 different DW techniques with 2 different b values (400 and 1000 s/mm2) and with/without the use of SENSE. The differences in signal-noise ratio values and image quality between DW images obtained with different techniques were compared using repeated-measures analysis of variance and Friedman test, respectively. A receiver operating characteristic analysis was applied to evaluate the apparent diffusion coefficient values as a discriminating variable to differentiate malignant lesions from benign ones; sensitivity and specificity were calculated.
There was no significant difference in the signal-noise ratio value and image quality between DW images obtained with b = 400 s/mm2 without SENSE (DW400) and b = 1000 s/mm2 with SENSE (DW1000SENSE). DW1000SENSE had the highest Az values for discriminating malignant from benign hepatic lesions (0.97) and hemangioma from metastasis (0.89). Using 1.63 x 10(-3) mm2/s as the cutoff value, DW1000SENSE had a sensitivity of 95.2% (40/42) and a specificity of 91.0% (40/44) for differentiating benign from malignant hepatic lesions. Using a cutoff value of 1.45 x 10(-3) mm2/s, DW1000SENSE had a sensitivity of 90.5% (19/21) and a specificity of 93.7% (15/16) for differentiating metastases from hemangiomas.
Diffusion-weighted imaging with a b value of 1000 s/mm2 and SENSE has the potential to differentiate hepatic focal lesions with improved sensitivity and specificity.
评估并行成像（灵敏度编码[SENSE]技术）对扩散加权（DW）磁共振成像的影响，比较具有两种不同b值的DW成像技术在肝脏局灶性病变特征描述中的作用，并确定表观扩散系数的临界值。
对78例患者的86个病变采用4种不同的DW技术进行检查，b值分别为400和1000 s/mm2，且分别在使用和不使用SENSE的情况下进行。分别采用重复测量方差分析和Friedman检验比较不同技术获得的DW图像之间的信噪比和图像质量差异。应用受试者操作特征分析来评估表观扩散系数值作为区分恶性病变与良性病变的判别变量；计算灵敏度和特异度。
在不使用SENSE的b = 400 s/mm2的DW图像（DW400）和使用SENSE的b = 1000 s/mm2的DW图像（DW1000SENSE）之间，信噪比和图像质量无显著差异。DW1000SENSE在区分肝脏恶性与良性病变（Az值为0.97）以及血管瘤与转移瘤（Az值为0.89）方面具有最高的Az值。以1.63×10(-3) mm2/s作为临界值，DW1000SENSE在区分肝脏良性与恶性病变时灵敏度为95.2%（40/42），特异度为91.0%（40/44）。以1.45×10(-3) mm2/s作为临界值，DW1000SENSE在区分转移瘤与血管瘤时灵敏度为90.5%（19/21），特异度为93.7%（15/16）。
b值为1000 s/mm2并结合SENSE的扩散加权成像有潜力以更高的灵敏度和特异度区分肝脏局灶性病变。
