Song Kyoung Doo, Kim Young Kon, Lee Won Jae, Lee Min Woo, Park Min Jung, Hwang Jiyoung, Lee Mi Hee
Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Acta Radiol. 2012 Jun 1;53(5):485-93. doi: 10.1258/ar.2012.110437. Epub 2012 Apr 25.
As diffusion-weighted imaging (DWI) is routinely incorporated into the standard clinical protocol, it is clinically relevant to determine whether DWI after gadoxetic acid is comparable to pre-contrast DWI, with regard to the detection and characterization of focal liver lesions.
To compare DWI before and after administration of gadoxetic acid in the detection and characterization of small (≤2.5 cm) focal hepatic lesions.
One hundred and fifty-eight patients with 237 focal hepatic lesions (≤2.5 cm) (124 HCCs, 50 metastases, 2 cholangiocarcinomas, 43 hemangiomas, and 18 cysts) were included. DWIs were obtained before and after administration of gadoxetic acid. Non-breath-hold DWI was performed with b values of 0, 100, and 800 s/mm(2). Signal-to-noise ratio (SNR), lesion-liver contrast-to-noise ratio (CNR), and apparent diffusion coefficients (ADCs) of the liver and lesion were calculated. Lesion detection with each DWI was evaluated with alternative free-response receiver-operating characteristic analysis by two observers. The sensitivity of the characterization of focal hepatic lesions as solid (malignancy) or non-solid (benignity) with each DWI was calculated using a five-point confidence scale. Inter-observer agreement regarding lesion detection and characterization was evaluated using kappa statistics.
SNRs of the liver on post-contrast DWI were significantly lower than on unenhanced DWI at b = 800 s/mm(2) (P < 0.05). SNRs, CNRs, and ADCs of focal hepatic lesions were not significantly different between two DWIs (P > 0.05). The diagnostic accuracy (Az) for lesion detection and the sensitivity for lesion characterization did not show significant difference between two DWIs (P > 0.05). With regard to the detection and characterization of focal hepatic lesions, the kappa values for two DWIs indicated good and excellent inter-observer agreement, respectively.
Gadoxetic acid-enhanced DWI showed comparable diagnostic capability to unenhanced DWI for the detection and characterization of small focal hepatic lesions.
由于扩散加权成像（DWI）已常规纳入标准临床方案，因此就局灶性肝病变的检测和特征而言，确定钆塞酸增强后的DWI是否与对比剂前DWI相当具有临床意义。
比较钆塞酸给药前后DWI在检测和特征化小（≤2.5 cm）局灶性肝病变中的作用。
纳入158例患者，共237个局灶性肝病变（≤2.5 cm）（124例肝细胞癌、50例转移瘤、2例胆管癌、43例血管瘤和18例囊肿）。在钆塞酸给药前后获取DWI。非屏气DWI在b值为0、100和800 s/mm²时进行。计算肝脏和病变的信噪比（SNR）、病变-肝脏对比噪声比（CNR）以及表观扩散系数（ADC）。由两名观察者通过交替自由反应接受者操作特征分析评估每次DWI的病变检测情况。使用五点置信量表计算每次DWI将局灶性肝病变定性为实性（恶性）或非实性（良性）的特征化敏感性。使用kappa统计评估观察者间在病变检测和特征化方面的一致性。
在b = 800 s/mm²时，对比剂增强后DWI上肝脏的SNR显著低于未增强DWI（P < 0.05）。两次DWI之间局灶性肝病变的SNR、CNR和ADC无显著差异（P > 0.05）。两次DWI之间病变检测的诊断准确性（Az）和病变特征化的敏感性无显著差异（P > 0.05）。就局灶性肝病变的检测和特征化而言，两次DWI的kappa值分别表明观察者间具有良好和极好的一致性。
钆塞酸增强DWI在检测和特征化小局灶性肝病变方面显示出与未增强DWI相当的诊断能力。
