Application Of Ultrasonography Acoustic Palpation Tissue Quantitative Technique In Pancreatic Focal Lesions

OBJECTIVE1. To observe the characteristics of the focal pancreatic lesions by using contrast-enhanced ultrasound.2. To evaluate the value of contrast-enhanced ultrasound and the quantitative parameters of time-intensity curve in the diagnosis and differential diagnosis of the focal pancreatic lesions.3. To discuss the feasibility of reconstructing the peripancreatic arteries by using three-dimensional contrast-enhanced ultrasound.METHODSSeventy-two patients with a total of 72 focal pancreatic lesions were prospectively evaluated with contrast-enhanced ultrasound. A diagnostic score of 1 to 5 was given to each lesion before and after contrast agent injection, and the diagnostic value was compared with ROC curve for differentiation between the benign and malignant focal pancreatic lesions; CEUS dynamic images of solid (including cystic-solid lesions) pancreatic lesions were quantitatively analysed with TIC, then evaluated the value of the quantitative parameters in the differential diagnosis between the benign and malignant focal pancreatic lesions; The peripancreatic arteries were reconstructed and displayed with 3D-CEUS in 17 patients, then observe the morphological characteristics and stereoscopic structures of the reconstructed peripancreatic arteries.RESULTS1. In the thirty-six malignant lesions,75.0% had unhomogeneous enhancement; while 26.1% for the benign and solid pancreatic lesions.76.9% of benign and cystic pancreatic lesions showed the enhancement of cystic wall and septum; while no enhancement for the remaining 23.1%. The enhancement pattern between malignant and benign pancreatic lesions had statistically significant difference(P<0.05).2. For the pathological pancreatic cancer,77.3% had persistent hypoenhancement, 22.7% showed isoenhancement in the arterial phase and hypoenhancement in the venous phase. Hypoenhancement without ring-like enhancement as a sign of pancreatic cancer had the sensitivity、specificity、positive predictive value、negative predictive value and accuracy of 96.6%、90.7%、87.5%、97.5% and 93.1%.3. 62.5% of the pancreatic neuroendocrine tumors showed hyperenhancement in the arterial phase, and it had the sensitivity、specificity、positive predictive value、 negative predictive value and accuracy of 62.5%、96.9%、71.4%、95.4% and 93.1%.4. The definitively diagnositic scores of 1 and 5 got by CEUS and combined diagnosis(conventiaonal ultrasound and CEUS) were more than by conventional ultrasound, while the equivocally diagnostic score of 3 was the exact contrary. There was statistically significant difference of diagnostic score between the conventional ultrasound and CEUS(P=0.000). The area under the receiver operating characteristic curve of the conventional ultrasound、CEUS and combined diagnosis was 0.681、0.931 and 0.958, respectively.5. The beginning time of malignant lesions was later than the adjacent parenchyma, with statistical difference (P<0.05), while there was no statistical difference between the benign lesions and adjacent parenchyma(P>0.05). The wash in slope was the slowest in pancreatic cancer(PC) followed by pancreatic inflammatory lesion(PIL)、other benign tmors(OBTs) and pancreatic neuroendocrine tumors(pNETs)(P<0.05);1min wash out slope:PIL>PC>pNETs>OBTs(P<0.05); and the peak intensity and area under the curve were the smallest in PC followed by PIL、OBTs and pNETs(P<0.05).6. The success rate of 3D-CEUS reconstruction of peripancreatic arteries was 94.1% in 17 patients. And 2 arterial involvement were found by rotation observation.CONCLUSIONS1. The combination of the macroscopic images of conventional ultrasound and the microcirculation perfusion of CEUS, can effectively improve the diagnostic accuracy of focal pancreatic lesions.2. CEUS can provide more objectively diagnostic information for the differentiation of focal pancreatic lesions by using quantitative parameters of TIC.3. 3D-CEUS can realize the stereoscopic display of peripancreatic arteries, and fit well with CT three-dimensional reconstruction, and its value of clinical applications needs further study.OBJECTIVE1. To evaluate the consistency of multiple measurements of shear wave velocity obtained by virtual touch tissue quantification.2. According to the final pathologic or clinical diagnosis, to discuss the potential value of the shear wave velocity in the differential diagnosis of benign and malignant focal solid pancreatic lesions.3. To evaluate the shear wave velocity of monitoring treatment response of advanced pancreatic cancer patients undergoing adjuvant therapy.METHODSConventional and acoustic radiation force impulse elastography were performed in fifty-one patients. To evaluate the reproducibility of the shear wave velocity measurements, the intraclass correlation coefficient (ICC) was calculated using a one-way random effects model. The value of differential diagnosis of shear wave velocity were assessed by lesional SWV、surrounding parenchymal SWV and the SWV difference values between the lesion and background parenchyma. For the advanced pancreatic cancer patients obtaining the final pathologic diagnosis by FNA or biopsy, and receiving the adjuvant therapy sequentially, we observed the change of the lesion size by follow-up.RESULTSThe mean intraclass correlation coefficient were 0.895 and 0.869 for the averaged quintuplet SWV measurements in the lesion and surrounding parenchyma, respectively. The mean SWV for lesion and surrounding parenchyma were 2.39±1.25 m/s(0.60-4.39 m/s) vs.1.59±0.63 m/s (0.76-3.22 m/s) in malignant group; and 2.06±1.08 m/s (0.79-4.00 m/s) vs.1.44±0.41 m/s (0.80-2.23 m/s) in benign group. There were statistically significant difference between the lesion SWV and adjacent parenchyma SWV in malignant and bengin group(P<0.05). However, the leison SWV、adjacent parenchyma SWV and SWV difference value got no statistic significance between malignant and benign group(P=0.320、0.352、0.581, respectively). The lesion SWV didn’t associate with the size(r=0.253, P>0.05); but had negative correlation with the depth of ROI(r=-0.413, P<0.05). For the nine advanced pancreatic cancer patients who received adjuvant theraphy, the mean SWV of the initial lesion of the good effect group and bad effect group were 2.92±0.80 m/s vs.0.92±0.32 m/s, respectively, with significantly statistic difference(P<0.05).CONCLUSIONS1. The reproducibility of shear wave velocity was good when the averaged quintuplet measurements were evaluated. More than one measurement can establish a reliable shear wave velocity.2. Further research will be needed to assess the value of differential diagnosis of benign and malignant focal pancreatic lesions by using shear wave velocity.3. No clear correlation was found between shear wave velocity and lesion size; The deeper ROI was associated with low shear wave velocity.4. The shear wave velocity of the initial lesion might have the potential clinical application value of predicting the adjuvant therapeutic effect in advanced pancreatic cancer patients.