Bracco Suisse SA, Geneva, Switzerland.
IEEE Trans Ultrason Ferroelectr Freq Control. 2010 Nov;57(11):2503-11. doi: 10.1109/TUFFC.2010.1716.
The differentiation between benign and malignant focal liver lesions plays an important role in diagnosis of liver disease and therapeutic planning of local or general disease. This differentiation, based on characterization, relies on the observation of the dynamic vascular patterns (DVP) of lesions with respect to adjacent parenchyma, and may be assessed during contrast-enhanced ultrasound imaging after a bolus injection. For instance, hemangiomas (i.e., benign lesions) exhibit hyper-enhanced signatures over time, whereas metastases (i.e., malignant lesions) frequently present hyperenhanced foci during the arterial phase and always become hypo-enhanced afterwards. The objective of this work was to develop a new parametric imaging technique, aimed at mapping the DVP signatures into a single image called a DVP parametric image, conceived as a diagnostic aid tool for characterizing lesion types. The methodology consisted in processing a time sequence of images (DICOM video data) using four consecutive steps: (1) pre-processing combining image motion correction and linearization to derive an echo-power signal, in each pixel, proportional to local contrast agent concentration over time; (2) signal modeling, by means of a curve-fitting optimization, to compute a difference signal in each pixel, as the subtraction of adjacent parenchyma kinetic from the echopower signal; (3) classification of difference signals; and (4) parametric image rendering to represent classified pixels as a support for diagnosis. DVP parametric imaging was the object of a clinical assessment on a total of 146 lesions, imaged using different medical ultrasound systems. The resulting sensitivity and specificity were 97% and 91%, respectively, which compare favorably with scores of 81 to 95% and 80 to 95% reported in medical literature for sensitivity and specificity, respectively.
肝脏局灶性病变的良恶性鉴别在肝脏疾病的诊断和局部或全身疾病的治疗方案制定中起着重要作用。这种鉴别基于病变的特征，依赖于观察病变相对于相邻实质的动态血管模式（DVP），并可在对比增强超声成像后通过团注造影剂进行评估。例如，血管瘤（即良性病变）随时间呈现高增强特征，而转移瘤（即恶性病变）在动脉期经常呈现高增强灶，随后总是呈现低增强。本工作旨在开发一种新的参数成像技术，旨在将 DVP 特征映射到单个图像中，称为 DVP 参数图像，该图像被视为一种用于特征病变类型的诊断辅助工具。该方法包括使用四个连续步骤处理图像时间序列（DICOM 视频数据）：（1）预处理，结合图像运动校正和线性化，以在每个像素中得出与随时间变化的局部造影剂浓度成正比的回声功率信号；（2）信号建模，通过曲线拟合优化，在每个像素中计算差分信号，作为相邻实质动力学从回声功率信号中的减法；（3）差分信号分类；和（4）参数图像渲染，以表示分类像素，作为诊断支持。总共对 146 个病变进行了 DVP 参数成像的临床评估，使用不同的医学超声系统进行成像。所得的灵敏度和特异性分别为 97%和 91%，与文献报道的灵敏度和特异性分别为 81%至 95%和 80%至 95%的评分相比具有优势。
