肝结核14例超声影像表现及诊断分析

目的探讨肝结核的超声影像表现及其临床诊断价值。方法回顾分析14例肝结核的超声影像图及临床资料。结果肝结核的影像表现主要为弥漫型、肿块型、脓肿型及钙化灶型。声像图表现缺少特征性。结论肝结核超声图像因其发展阶段及病理类型不同而表现多样,缺少特征性,临床易漏诊或误诊。确诊有赖于穿刺活检或手术病理检查。

Liver fibrosis identification based on ultrasound images captured under varied imaging protocols

Diagnostic ultrasound is a useful and noninvasive method in clinical medicine. Although due to its qualitative, sub- jective and experience-based nature, ultrasound image interpretation can be influenced by image conditions such as scanning frequency and machine settings. In this paper, a novel method is proposed to extract the liver features using the joint features of fractal dimension and the entropies of texture edge co-occurrence matrix based on ultrasound images, which is not sensitive to changes in emission frequency and gain. Then, Fisher linear classifier and support vector machine are employed to test a group of 99 in-vivo liver fibrosis images from 18 patients, as well as other 273 liver images from 18 normal human volunteers.

INTRAOPERATIVE ULTRASOUND FOR HEPATIC NEOPLASM DURING SURGERY

Objective.The purpose of this study was to determine the impact of intraoperative ultrasound(IOUS)on the management of patients with neoplasms of the liver. Methods.Forty nine patients operated on for liver or other pathologic processes were examined intraoperatively with 5.0 MHz special ultrasound transducers during surgical exploration of the abdomen.Subjects were evaluated because of known or suspected disease of the liver.Preoperative imaging studies included percutaneous ultrasound(n=49),magnetic resonance imaging(n=11),and computed tomography(n=34).Intraoperative evaluation on all patients included inspection,bimanual palpation,and ultrasonography.Comparison between preoperative imagings and IOUS were analysed. Results.Sensitivity for detection of hepatic neoplasms showed in intraoperative ultrasound,percutaneous ultrasound,magnetic resonance imaging and computed tomography as 100%(23/23),74%(17/23),74%(14/19) and 75%(6/8).Specificity showed 100%(26/26),100%(26/26),93%(14/15) and 67(2/3).In seven patients(14%),the neoplasms were not found by inspection,bimanual palpation,and identified only by IOUS. Conclusions.Intraoperative ultrasound is the most sensitive and specific method for detection and surgery of liver neoplasms,especially the occult neoplasms and small size lesion(<2cm).

Contrast-enhanced ultrasonography parameters in neural network diagnosis of liver tumors

AIM:To study the role of time-intensity curve(TIC) analysis parameters in a complex system of neural networks designed to classify liver tumors.METHODS:We prospectively included 112 patients with hepatocellular carcinoma(HCC)(n = 41),hypervascular(n = 20) and hypovascular(n = 12) liver metastases,hepatic hemangiomas(n = 16) or focal fatty changes(n = 23) who underwent contrast-enhanced ultrasonography in the Research Center of Gastroenterology and Hepatology,Craiova,Romania.We recorded full length movies of all contrast uptake phases and post-processed them offline by selecting two areas of interest(one for the tumor and one for the healthy surrounding parenchyma) and consecutive TIC analysis.The difference in maximum intensities,the time to reaching them and the aspect of the late/portal phase,as quantified by the neural network and a ratio between median intensities of the central and peripheral areas were analyzed by a feed forward back propagation multi-layer neural network which was trained to classify data into five distinct classes,corresponding to each type of liver lesion.RESULTS:The neural network had 94.45% training accuracy(95% CI:89.31%-97.21%) and 87.12% testing accuracy(95% CI:86.83%-93.17%).The automatic classification process registered 93.2% sensitivity,89.7% specificity,94.42% positive predictive value and 87.57% negative predictive value.The artificial neural networks(ANN) incorrectly classified as hemangyomas three HCC cases and two hypervascular metastases,while in turn misclassifying four liver hemangyomas as HCC(one case) and hypervascular metastases(three cases).Comparatively,human interpretation of TICs showed 94.1% sensitivity,90.7% specificity,95.11% positive predictive value and 88.89% negative predictive value.The accuracy and specificity of the ANN diagnosis system was similar to that of human interpretation of the TICs(P = 0.225 and P = 0.451,respectively).Hepatocellular carcinoma cases showed contrast uptake during the arterial phase followed by wash-out in the portal and first seconds of the late phases.For the hypovascular metastases did not show significant contrast uptake during the arterial phase,which resulted in negative differences between the maximum intensities.We registered wash-out in the late phase for most of the hypervascular metastases.Liver hemangiomas had contrast uptake in the arterial phase without agent wash-out in the portallate phases.The focal fatty changes did not show any differences from surrounding liver parenchyma,resulting in similar TIC patterns and extracted parameters.CONCLUSION:Neural network analysis of contrastenhanced ultrasonography-obtained TICs seems a promising field of development for future techniques,providing fast and reliable diagnostic aid for the clinician.

Value of contrast-enhanced ultrasound in diagnosis of focal liver lesions

Objective： By observing the pattern of the focal liver lesions （FLL） in different phases by real time contrast-enhanced ultrasound （CEUS）, compared to enhanced CT, investigate the value of CEUS in diagnosing focal liver lesions. Meth. ods： 35 patients with unconfirmed focal liver lesions were studied by contrast agent SonoVue and Technos DU 8 produced by Esaote company. Results： Among the 14 cases of hepatocellular carcinoma （HCC）, 10 were typical, presented with early artery enhancement and immediate wash-out. The enhancement patterns of 6 livers metastasis were diverse, including peripheral or entire degree enhancement. The wash-out time in malignant tumors was eadier than other focal liver lesions （P 〈 0.05）, appeared as hypoechoic in the portal phase or parenchyma phase. The 6 cases of hemangioma were enhanced centripetally nodular in artery phase and washed out after several minutes. The patterns of different lesions were similar compared to contrast-enhanced CT, without significant statistic differences. Conclusion： The contrast enhanced ultrasound technique can significantly improved the value of diagnosing focal liver lesions.

In Vitro Study of Ultrasound on Multidrug Resistance in MDR Human Hepatoma HepG_2 Cells

OBJECTIVE The aim of the study was to examine the reversal effects of ultrasound （US） on the MDR in HepG2/ADM, a HepG2 cell line resistant to Adriamycin （ADM）, and to study the mechanism of US action.METHODS Using the MTT assay, the effects of US on MDR in HepG2/ADR cells were studied. Before and after the treatment with 0.5 W/cm^2 low intensity ultrasound （LIUS）, the expression of the MDR-related genes, mdrl, mrp and lrp was assayed with the reverse transcriptase polymerase chain reaction （RT-PCR） and the levels of their respective protein expression determined by flow cytometry. By using confocal laser scanning microscopy （CLSM）, we examined the intracellular daunorubicin （DNR） distribution, and the effects on the cells of treatment with US or DNR.RESULTS LIUS significantly reversed MDR in HepG2/ADR cells. After treatment with LIUS at 0.5 W/cm^2, chemosensitivity to ADM and DNR increased 3.35-fold and 2.81-fold, respectively. The reversal activity by LIUS plus verapamil （VER） was stronger than with either US or VER alone. After treatment with 0.5 W/cm^2, the expression of both the MDR1 and the MRP mRNA genes began to decline （P 〈 0.01 and P 〈 0.05, respectively）; the expression of LRP showed no significant changes. Changes in the expression of the P-glycoprotein （P-gp） and MRP were similar to those of their mRNA expressions. Results of the CLSM showed that administration of US （0. 5 W/cm^2） or VER （15.7 uM） with DNR to HepGa/ADM cells showed a significant change in the distribution of DNR in the cells.CONCLUSION Our results show that LIUS can reverse MDR. The reversal effects are stronger than those of either US or VER alone, when combined with VER administration. As LIUS is noninvasive causing no toxicity, it might have potential for clinical application. The reversal mechanism needs further study.