Opačić Dalibor, Rustemović Nadan, Kalauz Mirjana, Markoš Pave, Ostojić Zvonimir, Majerović Matea, Ledinsky Iva, Višnjić Ana, Krznarić Juraj, Opačić Milorad
Dalibor Opačić, Zvonimir Ostojić, Clinical Hospital Center Zagreb, 10000 Zagreb, Croatia.
World J Gastroenterol. 2015 Apr 7;21(13):4014-9. doi: 10.3748/wjg.v21.i13.4014.
To investigate the accuracy of the strain histogram endoscopic ultrasound (EUS)-based method for the diagnostic differentiation of patients with pancreatic masses.
In a prospective single center study, 149 patients were analyzed, 105 with pancreatic masses and 44 controls. Elastography images were recorded using commercially available ultrasound equipment in combination with EUS linear probes. Strain histograms (SHs) were calculated by machine integrated software in regions of interest and mean values of the strain histograms were expressed as Mode 1 (over the mass) and Mode 2 (over an adjacent part of pancreatic tissue, representing the reference area). The ratio between Mode 2 and Mode 1 was calculated later, representing a new variable, the strain histogram ratio. After the final diagnosis was established, two groups of patients were formed: a pancreatic cancer group with positive cytology achieved by fine needle aspiration puncture or histology after surgery (58 patients), and a mass-forming pancreatitis group with negative cytology and follow-up after 3 and 6 mo (47 patients). All statistical analyses were conducted in SPSS 14.0 (SPSS Inc., Chicago, IL, United States).
Results were obtained with software for strain histograms with reversed hue scale (0 represents the hardest tissue structure and 255 the softest). Based on the receiver operating characteristics (ROC) curve coordinates, the cut-off point for Mode 1 was set at the value of 86. Values under the cut-off point indicated the presence of pancreatic malignancy. Mode 1 reached 100% sensitivity and 45% specificity with overall accuracy of 66% (95%CI: 61%-66%) in detection of pancreatic malignant tumors among the patients with pancreatic masses. The positive and negative predictive values were 54% and 100%, respectively. The cut-off for the new calculated variable, the SH ratio, was set at the value 1.153 based on the ROC curve coordinates. Values equal or above the cut-off value were indicative of pancreatic malignancy. The SH ratio reached 98% sensitivity, 50% specificity and an overall accuracy of 69% (95%CI: 63%-70%). The positive and negative predictive values were 92% and 100%, respectively.
SH showed high sensitivity in pancreatic malignant tumor detection but disappointingly low specificity. Slight improvements in specificity and accuracy were achieved using the SH ratio.
探讨基于应变直方图的内镜超声（EUS）方法对胰腺肿块患者进行诊断鉴别的准确性。
在一项前瞻性单中心研究中，分析了149例患者，其中105例有胰腺肿块，44例为对照。使用市售超声设备结合EUS线性探头记录弹性成像图像。通过机器集成软件在感兴趣区域计算应变直方图（SHs），应变直方图的平均值表示为模式1（在肿块上）和模式2（在胰腺组织的相邻部分，代表参考区域）。随后计算模式2与模式1之间的比值，代表一个新变量，即应变直方图比值。在确定最终诊断后，将患者分为两组：通过细针穿刺抽吸细胞学检查阳性或术后组织学检查确诊的胰腺癌组（58例），以及细胞学检查阴性且随访3个月和6个月后的肿块型胰腺炎组（47例）。所有统计分析均在SPSS 14.0（美国伊利诺伊州芝加哥SPSS公司）中进行。
使用具有反向色调标度的应变直方图软件获得结果（0代表最硬的组织结构，255代表最软的组织结构）。根据受试者操作特征（ROC）曲线坐标，模式1的截断点设定为86。截断点以下的值表明存在胰腺恶性肿瘤。在胰腺肿块患者中检测胰腺恶性肿瘤时，模式1的敏感性达到100%，特异性为45%，总体准确率为66%（95%CI：61%-66%）。阳性和阴性预测值分别为54%和100%。根据ROC曲线坐标，新计算变量SH比值的截断点设定为1.153。等于或高于截断值的值表明存在胰腺恶性肿瘤。SH比值的敏感性达到98%，特异性为50%，总体准确率为69%（95%CI：63%-70%）。阳性和阴性预测值分别为92%和100%。
SH在胰腺恶性肿瘤检测中显示出高敏感性，但特异性低得令人失望。使用SH比值可在特异性和准确性方面略有提高。
