The Value Of Contrast-enhanced Ultrasound In Resection Of Cerebral Glioma

Objective：By observing the glioma patients who the characteristics ofconventional ultrasound and contrast-enhanced ultrasound, quantitativeanalysis of the tumor blood perfusion characteristics, real-timemonitoring scope and degree of tumor excision, discusses the value ofcontrast-enhanced ultrasound in resection of cerebral glioma.Methods：70patients who were doubted cerebral glioma by computedtomography (CT) or magnetic resonance (MR) test in our hospital fromOctober2012to2015were involved in this study, confirming bypathology after operation, grading standard reference WHO2007central nervous system tumors,34cases of low grade gliomas,36casesof high grade gliomas. They are all through microscope neurosurgicaloperation to remove the tumor and using conventional ultrasound andCEUS examination. Before tumor resection, the ultrasonic probe wasplaced lightly on the surface of the brain during the operation. Theapplication of conventional ultrasound scanning to observe the location,morphology, boundary, the blood flow signal distribution and the relationship with the surrounding tissue and blood vessels of the tumor, tomeasure the tumor size and the distance of the tumor to the brain surface.Then the injection of ultrasound contrast agents, the real-time observationof the tumor and tumor tissues blood flow perfusion and enhancedfeatures, once again clear border of tumor. After resection of the tumorundergoing contrast-enhanced ultrasound, observation enhancementcharacteristics of the residual cavity wall and adjacent brain tissue, judgethe residue of the tumor. Combined with postoperative pathologicaldiagnosis, analysis of conventional ultrasound and contrast-enhancedultrasound results, compare two methods of application value.Results：All lesions were indentified and located with100%accuracy byconventional ultrasound guidance. The process of operation become moresmoothly without complication. In70cases of glioma with postoperativepathological diagnosis, there are34cases in low grade glioma (6cases ingradeⅠ,28cases in grade Ⅱ), and36cases in high grade glioma (17cases in grade Ⅲ,19cases in grade Ⅳ).Conventional ultrasound showsthat the differences of boundary and echo was statistically significantbetween high and low grade gliomas (P＜0.05), but no significantdifferences of form and edema around tumor (P＞0.05). There arestatistically significant differences of edema around tumor between highand low grade gliomas by contrast-enhanced ultrasound (P＜0.05). Quantitative analysis the characteristics of contrast-enhancedultrasound parameters between high and low grade glioma: low gradegliomas, the rising time （RT）：15.86±1.04s, time to peak（TTP）：29.73±1.03s, maximum intensity（IMAX）：553.34±29.64%; high gradegliomas, RT:13.27±0.83s, TTP:25.25±1.09s, IMAX：884.67±34.93%.There are statistically significant differences of RT、 TTP and IMAXbetween high and low grade gliomas (P＜0.05).After tumor resection,173tissues in the residual cavity and thesurrounding brain tissue were sent for pathological examination. Then theresult is that residual tumor is33, no tumor is140. Conventionalultrasound judged that residual tumor is30, no tumor is143.Contrast-enhanced ultrasound judged that residual tumor is32, no tumoris141. The sensitivity of judging residual tumor by conventionalultrasound is60.6%, specificity is92.8%, accuracy rate is86.7%, falsepositive rate is7.1%and false negative rate is39.4%, however, thesensitivity of contrast-enhanced ultrasound is84.8%, specificity is97.1%,accuracy rate is94.8%, false positive rate is2.9%and false negative rateis15.2%. Contrast-enhanced ultrasound to judge residual tumor is betterthan in conventional ultrasound. There are statistically significantdifferences of sensitivity, accuracy and false negative rate betweenconventional ultrasound and contrast-enhanced ultrasound（P＜0.05）, butno significant differences of specificity and false positive rate（P＞0.05）. Conclusions：1. Intra-operative contrast-enhanced ultrasound in determining theborder of glioma, to distinguish between tumor and brain edema is betterthan that of conventional ultrasound, so as to improve the total removalrate of the tumor.2. Intra-operative contrast-enhanced ultrasound had a higherspecificity in the diagnosis of glioma in different pathological grades,contribute to the judgment of tumor pathological grade, improve thedifferential diagnosis of malignant and benign tumors, and give a reliablebasis to the decision of surgical and therapeutic plan.3. Intra-operative contrast-enhanced ultrasound has good clinicalauxiliary value to judge residual tumor after glioma resection, guide theoperator timely removal of residual tumor, reduce the postoperativerecurrence of tumor.