The role of contrast-enhanced sonography for radiofrequency ablation of liver tumors.

OBJECTIVE: To assess the feasibility and usefulness of contrast-enhanced sonography for tumor detection and guidance of liver VX2 tumor ablation and to evaluate post radiofrequency ablation effectiveness. METHODS: VX2 tumors were implanted into the livers of 6 rabbits. Both conventional and harmonic gray scale and power Doppler imaging were performed with a commercially available scanner to evaluate the liver tumors before and after intravenous injection of a sonographic contrast agent before and after radiofrequency ablation. Contrast-enhanced imaging was used to detect the tumors before ablation, to guide needle insertion, and to measure the ablation sites after radiofrequency ablation. Pathologic examination was performed for comparison. RESULTS: Three tumors were seen without contrast enhancement, whereas 10 tumors (<1 cm) were detected with contrast enhancement. Intentionally, 2 tumors were completely ablated and 5 tumors were partially ablated. In 3 cases, incompletely ablated tumors could only be identified on contrast-enhanced Doppler imaging by enhancing the detection of residual tumor vascularity. There was excellent concordance between sonographic imaging and gross pathologic findings. CONCLUSIONS: Contrast-enhanced sonographic imaging appears useful for detection of liver tumors and for guiding and monitoring tumor ablation therapies.     

Early assessment of the therapeutic response to radio frequency ablation for hepatocellular carcinoma: utility of gray scale harmonic ultrasonography with a microbubble contrast agent.

OBJECTIVE: To evaluate the utility of gray scale harmonic ultrasonography with a microbubble contrast agent in the early assessment of the therapeutic response to radio frequency ablation for hepatocellular carcinoma. METHODS: Seventy-five patients with 81 nodular hepatocellular carcinomas (1.3-4.8 cm) treated with percutaneous radio frequency ablation were evaluated with contrast-enhanced gray scale harmonic ultrasonography after intravenous bolus injection of a galactose-based microbubble contrast agent. The vascularity within the ablation zones was evaluated with a continuous scan for 3 to 5 seconds between 15 and 30 seconds after initiation of contrast agent injection. To evaluate the perfusion of the ablation zones, intermittent stimulated acoustic emission imaging was performed with a rapid sweeping technique from the end of the continuous scan. All patients underwent follow-up 3-phase helical computed tomography at 1 month after radio frequency ablation and were followed for at least 1 year. The results of contrast-enhanced ultrasonography were compared with those of follow-up computed tomography in terms of the presence or absence of residual unablated tumors. RESULTS: In 10 (12%) of the 81 treated hepatocellular carcinomas, contrast-enhanced ultrasonography showed either nodular or crescentic enhancing foci at the margins of ablation zones, suggesting residual unablated tumors. Contrast-enhanced computed tomography obtained 1 month after radio frequency ablation confirmed the residual unablated tumors in the same 10 lesions. Diagnostic agreement between 1-month follow-up computed tomography and contrast-enhanced ultrasonography was achieved in all 81 cases (100%). CONCLUSIONS: Contrast-enhanced gray scale harmonic ultrasonography can be a reliable alternative to contrast-enhanced computed tomography in the early assessment of the therapeutic response to radio frequency ablation for hepatocellular carcinoma.     

Ablation therapy guided by contrast-enhanced sonography with Sonazoid for hepatocellular carcinoma lesions not detected by conventional sonography.

OBJECTIVE: We evaluated the usefulness of contrast-enhanced harmonic gray scale sonography with a newly developed sonographic contrast medium as a means of guidance for percutaneous ablation therapy of hepatocellular carcinoma lesions not detected by conventional sonography. METHODS: We examined 85 patients with 108 hepatocellular carcinoma lesions that were identified as hypervascular by multidetector-row computed tomography by using contrast-enhanced harmonic gray scale sonography after injection of Sonazoid (GE Healthcare, Oslo, Norway), a lipid-stabilized suspension of a perfluorobutane gas microbubble contrast agent. We scanned the whole liver by this modality at a low mechanical index in the late phase to detect lesions not detected by conventional sonography and then scanned the lesions again by this modality at a high mechanical index to visualize tumor vessels and enhancement. We also performed percutaneous ablation therapy guided by this modality to treat viable hepatocellular carcinoma lesions that could not be detected by conventional sonography. RESULTS: Conventional sonography identified 90 (83%) of 108 hepatocellular carcinoma lesions; 15 (14%) additional viable lesions not detected by conventional sonography were detected in the late phase of contrast-enhanced harmonic gray scale sonography at a low mechanical index, and tumor vessels and enhancement were observed in the late phase at a high mechanical index. Contrast-enhanced harmonic gray scale sonography diagnosed 105 (97%) of the 108 viable hepatocellular carcinoma lesions, and 14 (93%) of the 15 lesions not detected by conventional sonography were successfully treated by percutaneous ablation therapy guided by this modality. CONCLUSIONS: Contrast-enhanced harmonic gray scale sonography is useful for guidance of percutaneous ablation therapy of hepatocellular carcinoma lesions not detected by conventional sonography.     

Contrast-enhanced sonography of autoimmune pancreatitis: comparison with pathologic findings.

OBJECTIVE: We evaluated the vascularity of autoimmune pancreatitis lesions on contrast-enhanced harmonic gray scale sonographic images in comparison with the pathologic findings. METHODS: Six patients with autoimmune pancreatitis were examined. All patients held their breath from 20 to 50 seconds after the injection of a contrast agent while the vascularity of the lesion was examined by contrast-enhanced harmonic gray scale sonography (early phase), and lesion enhancement was monitored at about 90 seconds after the injection while the patients held their breath for a few seconds (delayed phase). We then compared the vascularity on the contrast-enhanced harmonic gray scale sonographic images with the pathologic findings (fibrosis and inflammation) in all lesions. The vascularity of 3 of the 6 lesions was also evaluated by contrast-enhanced harmonic gray scale sonography before and after treatment with corticosteroids. RESULTS: The autoimmune pancreatitis lesions exhibited mild (n = 1), moderate (n = 3), or marked (n = 2) enhancement throughout almost the entire lesions in both the early and delayed phases. The grade of lesion vascularity on the contrast-enhanced harmonic gray scale sonographic images correlated with the pathologic grade of inflammation and inversely correlated with the grade of fibrosis associated with autoimmune pancreatitis. The vascularity of all 3 lesions had decreased on the contrast-enhanced harmonic gray scale sonographic images after steroid therapy. CONCLUSIONS: Contrast-enhanced harmonic gray scale sonography may be useful for evaluating the vascularity of autoimmune pancreatitis lesions and the therapeutic efficacy of steroid therapy.     

Contrast-enhanced sonography of small pancreatic mass lesions.

OBJECTIVE: To evaluate the usefulness of contrast-enhanced wideband harmonic gray scale sonography in assessing the vascularity of small pancreatic mass lesions. METHODS: Twenty-five patients with 25 pancreatic mass lesions (20 pancreatic carcinomas, 1 islet cell tumor, 1 malignant lymphoma, and 3 focal inflammatory pancreatic masses due to chronic pancreatitis) were examined. All patients held their breath for 20 to 50 seconds after injection of a contrast agent while the vascularity of the tumor was observed on contrast-enhanced wideband harmonic gray scale sonography (early phase). We then monitored the tumor enhancement 60 to 120 seconds after the injection while the patients held their breath for a few seconds (delayed phase). RESULTS: All 20 (100%) of the pancreatic carcinomas showed no contrast enhancement in the early phase. Fifteen (75%) of the 20 pancreatic carcinomas also showed no contrast enhancement in the delayed phase. The remaining 5 (25%) pancreatic carcinomas showed mild enhancement in the peripheral regions of the tumor in the delayed phase. The other pancreatic masses showed mild or pronounced enhancement throughout the entire lesions in both the early and delayed phases. CONCLUSIONS: Contrast-enhanced wideband harmonic gray scale sonography is a useful tool for differentiating pancreatic carcinomas from focal inflammatory pancreatic masses or hypervascular pancreatic tumors.     

低机械指数谐波超声造影评估肝细胞癌介入治疗效果

目的 探讨低机械指数谐波超声造影在肝细胞癌(HCC)介入治疗中对疗效的评估价值.方法 对82例介入治疗的HCC患者分别于治疗前后进行低机械指数超声谐波造影、常规二维灰阶超声、彩色多普勒血流成像(CDFI)和增强CT和(或)MRI检查,记录病灶数目、大小,观察病灶内血供.结果 82例患者介入治疗前二维超声及CDFI共检出病灶119个,超声造影共检出病灶142个;治疗前后超声造影显示病灶范围均较二维超声所示增大;病灶内血流信号检测以超声造影最准确.结论 超声造影能较好地评估HCC介入治疗的疗效.     

Assessment of therapeutic response in hepatocellular carcinoma treated with percutaneous radio frequency ablation: comparison of multiphase helical computed tomography and power Doppler ultrasonography with a microbubble contrast agent.

OBJECTIVE: To compare the results of multiphase helical computed tomography and power Doppler ultrasonography with a microbubble contrast agent in the assessment of the therapeutic response to radio frequency ablation in hepatocellular carcinoma. METHODS: In 66 patients with 73 nodular hepatocellular carcinomas ranging from 1.0 to 4.0 cm (mean, 2.6 cm) in diameter, contrast-enhanced power Doppler ultrasonography was performed after intravenous bolus injection of a galactose-based microbubble contrast agent before and after radio frequency ablation. The results of the studies were compared with the findings of follow-up 3-phase helical computed tomography. All patients were regularly followed up with computed tomography for more than 1 year (range, 13-19 months). RESULTS: In 8 (11%) of 73 hepatocellular carcinomas, immediate follow-up computed tomography obtained within 2 hours after radio frequency ablation showed focal enhancing portions within the treated lesions, suggesting residual non-necrotic tumors. All 8 of these tumors had intratumoral flow signals on contrast-enhanced power Doppler ultrasonography. The diagnostic agreement between computed tomography and contrast-enhanced power Doppler ultrasonography was achieved in 100%. Among the remaining 65 hepatocellular carcinomas with the absence of residual tumors at both immediate follow-up computed tomography and contrast-enhanced power Doppler ultrasonography, subsequent follow-up computed tomography showed local regrowth at the margins of 10 lesions (15%). CONCLUSIONS: The results of contrast-enhanced power Doppler ultrasonography closely correlated with those of immediate follow-up computed tomography for detecting residual tumors in hepatocellular carcinomas treated with radio frequency ablation. Both techniques, however, showed a limitation in detecting small or microscopic residual tumors and in predicting local regrowth in the treated lesions.     

Small hepatocellular carcinoma: therapeutic effectiveness of percutaneous radio frequency ablation therapy with a LeVeen needle electrode.

OBJECTIVE: To evaluate the therapeutic effectiveness of percutaneous radio frequency ablation of small (< or =3-cm) hepatocellular carcinoma with a LeVeen needle electrode. METHODS: Thirty patients (mean age, 65.7 years) with 32 hepatocellular carcinomas (range, 1.2-3.0 cm; mean, 2.3+/-0.5 cm) underwent percutaneous radio frequency ablation to the center of the hepatocellular carcinoma after expansion of the inner needles. The manufacturer's recommended radio frequency ablation protocol was used. Posttreatment contrast-enhanced color Doppler sonography, contrast-enhanced computed tomography, and fine-needle biopsy were performed to assess the radio frequency ablation-induced coagulated necrosis. RESULTS: Severe intratreatment pain made us abort radio frequency ablation in 2 patients. Complete tumor necrosis was achieved in 1 treatment session with 1 needle electrode insertion in 28 (93.4%) of 30 nodules (28 patients). We found no residual focus on both color Doppler sonography and computed tomography after any of the sessions. In follow-ups ranging from 3 to 15 months (mean, 8.4 months), no local recurrence was found in cases with complete tumor ablation. CONCLUSIONS: Radio frequency ablation with the LeVeen needle electrode was effective, obtaining complete coagulated necrosis with a safety margin when used for the treatment of small hepatocellular carcinomas.     

Therapeutic response evaluation of malignant hepatic masses treated by interventional procedures with contrast-enhanced agent detection imaging.

OBJECTIVE: To assess the usefulness of microbubble contrast-enhanced agent detection imaging in evaluating the therapeutic response of malignant hepatic masses to treatment with interventional procedures. METHODS: Fifty-eight patients with 68 hepatocellular carcinomas and 6 metastases who were treated with interventional procedures were evaluated with SH U 508A-enhanced agent detection imaging and helical computed tomography. Helical computed tomography was also performed to help establish the outcome of therapy with unenhanced computed tomography 2 weeks after transcatheter arterial chemoembolization and with dynamic contrast-enhanced computed tomography 1 day after radio frequency ablation or percutaneous ethanol injection. The studies were reviewed separately and randomly, and the sensitivity and specificity of agent detection imaging for detection of viable tumor residue were determined by follow-up imaging performed at least 3 months later. RESULTS: Follow-up computed tomography or magnetic resonance imaging revealed complete tumor responses in 44 (59.5%) of 74 cases after the therapeutic procedures. The sensitivity of agent detection imaging was 94.7% after transcatheter arterial chemoembolization and 72.7% after radio frequency ablation and percutaneous ethanol injection. The specificity of agent detection imaging for the detection of residual tumors was 80% after transcatheter arterial chemoembolization and 79.2% after radio frequency ablation and percutaneous ethanol injection. The false-positive rate for agent detection imaging in cases of radio frequency ablation or percutaneous ethanol injection was 20.8% (5 of 24), resulting from reactive hyperemia or vascularity within the safety margin. In the assessment of the therapeutic effects, the concordance of contrast-enhanced agent detection imaging with helical computed tomography was statistically significant after transcatheter arterial chemoembolization (P < .00001) and radio frequency ablation or percutaneous ethanol injection (P < .02). CONCLUSIONS: Contrast-enhanced agent detection imaging proved useful and as effective as helical computed tomography for evaluating the therapeutic effects of interventional therapeutic procedures for malignant hepatic masses.     

Contrast-enhanced two- and three-dimensional sonography for evaluation of intra-abdominal hemorrhage.

OBJECTIVE: To determine whether a contrast agent enhances sonographic detection of bleeding sites in the abdomen and whether contrast-enhanced three-dimensional sonography provides additional information compared with contrast-enhanced two-dimensional sonography. METHODS: Bleeding sites were created within the livers (n = 3), spleens (n = 5), and kidneys (n = 3) of 3 dogs. A sonographic contrast agent with vascular and parenchymal enhancement capabilities was administered intravenously at a dose of 0.02 mL/kg. Before and after each contrast agent injection, the bleeding sites were imaged with two- and three-dimensional sonography in gray scale harmonic imaging and color flow modes. Sonographic findings were compared with gross pathologic findings. RESULTS: Noncontrast-enhanced sonography was not able to show the specific location of the active bleeding in any of the organs evaluated. The contrast agent enhanced the sonographic detection of blood flow in normal vessels and extravasated blood from damaged vessels or organs in all cases. Intrasplenic and intrahepatic hematomas were better identified on delayed imaging sequences because there was marked enhancement of the normal parenchyma, whereas the hematomas remained unenhanced. Reconstructed three-dimensional sonography showed spatial relationships of the bleeding sites and surrounding structures. Gross pathologic findings were consistent with the contrast-enhanced sonographic results. CONCLUSIONS: Contrast-enhanced sonography improves the detection and evaluation of abdominal bleeding sites. Contrast-enhanced three-dimensional sonography appears to provide additional information when compared with two-dimensional sonography.     

肝脏肿瘤谐波造影三维超声与造影二维超声的比较

目的通过与谐波造影二维超声的比较．探讨谐波造影三维超声在评价肝脏肿瘤血供中的作用。方法采用编码谐波造影功能对21例肝脏肿瘤患者行造影二维超声检查，并在此基础上进行三维重建，比较两者在显示肿瘤血管像、灌注像、血管及灌注综合像方面的不同。结果谐波造影三维超声较造影二维超声能更清楚地显示肿瘤的血管像，显示血管及灌注综合像的能力亦优于造影二维超声，但在显示肿瘤灌注像方面，二者作用相似。结论谐波造影三维超声能更好地反映肝脏肿瘤的血供特点，可为肝脏肿瘤的影像研究提供一种新方法。     

低机械指数谐波超声造影在局灶性肝病治疗适应证选择中的应用

目的:探讨低机械指数谐波超声造影在局灶性肝脏病变治疗适应证选择中的应用价值。方法:对232例(共357个结节)局灶性肝脏病变患者进行低机械指数谐波超声造影、增强CT/MR和/或病理检查。结果:低机械指数谐波超声造影诊断肝脓肿10例,患者行超声导向穿刺抽脓、局部注药治疗;诊断恶性肿瘤147例,其中82例行非手术治疗,包括7例行经皮无水乙醇注射治疗,57例行射频消融或微波凝固治疗,14例行肝动脉化疗栓塞或经皮无水乙醇注射治疗联合射频消融,4例行肝动脉化疗栓塞。结论:超声造影有助于肝脏局灶性病变治疗适应证的选择。     

Contrast-enhanced, wide-band harmonic gray scale imaging of hepatocellular carcinoma: correlation with helical computed tomographic findings.

We evaluated the usefulness of contrast-enhanced, wide-band harmonic gray scale imaging for the diagnosis of hepatocellular carcinoma and compared it with helical computed tomography. Forty-eight patients with 61 hepatocellular carcinoma lesions were scanned by contrast-enhanced, wide-band harmonic gray scale imaging after an intravenous bolus injection of the contrast agent Levovist. Fifty-seven of the 61 hepatocellular carcinoma lesions showed hypervascular enhancement, and intratumoral vessels could be observed in 40 of the 57 lesions. Helical computed tomography revealed a high-attenuation area in 54 of the 61 lesions, whereas the other lesions showed an equivocal-attenuation area. Contrast-enhanced, wide-band harmonic gray scale imaging is a useful method for diagnosing the vascularity of hepatocellular carcinoma.     

Assessment of the therapeutic response of hepatocellular carcinoma treated with transcatheter arterial chemoembolization: comparison of contrast-enhanced sonography and 3-phase computed tomography.

OBJECTIVE: The purpose of this study was to compare contrast-enhanced sonography with 3-phase computed tomography (CT) in assessing the therapeutic response of hepatocellular carcinomas (HCCs) treated with transcatheter arterial chemoembolization (TACE). METHODS: Twenty-nine nodular HCCs treated with TACE were examined with contrast-enhanced sonography, 3-phase helical CT, and conventional angiography. Contrast-enhanced sonographic and CT findings were interpreted separately and prospectively for the presence or absence of contrast enhancement in the treated HCCs. Conventional angiography served as the reference standard. RESULTS: Intratumoral enhancement was seen in 19 HCCs (61%) on contrast-enhanced sonography and 12 HCCs (39%) on CT. Enhancement patterns on sonography were blush in 8 (42%), branching in 2 (11%), nodular in 4 (21%), and stippled in 5 (26%). Of the 19 HCCs with intratumoral enhancement on contrast-enhanced sonography, 13 (68%) showed tumor staining on angiography. Of the 12 HCCs without intratumoral enhancement on sonography, 1 (8%) showed tumor staining on angiography. The sensitivity and specificity of contrast-enhanced sonography in depicting flow in HCCs treated with TACE were 93% and 65%, respectively. The sensitivity and specificity of 3-phase CT were 64% and 100%. CONCLUSIONS: Contrast-enhanced sonography is a more sensitive imaging method than 3-phase CT in depicting vascularity in HCCs treated with TACE.     

Evaluation of hepatic focal nodular hyperplasia with contrast-enhanced gray scale harmonic sonography: initial experience.

OBJECTIVE: To assess the potential of contrast-enhanced gray scale harmonic sonography in the evaluation of the typical vascular and enhancement patterns of hepatic focal nodular hyperplasia. METHODS: Thirteen patients with 13 lesions of hepatic focal nodular hyperplasia underwent contrast-enhanced gray scale harmonic sonography. After the injection of a microbubble contrast agent (SH U 508A), gray scale harmonic sonographic studies using a Coded Harmonic Angio technique were performed with a combination of a period of continuous scanning to assess the vascular pattern (vascular imaging) and interval delay scanning to determine the sequential enhancement pattern (acoustic emission imaging). Each imaging pattern was categorized and analyzed by consensus of 2 experienced radiologists. RESULTS: In 12 (92%) of 13 lesions, vascular imaging during the arterial phase showed central arteries of a spoked wheel pattern, whereas the remaining lesion had stippled vascularity. On acoustic emission imaging, 11 (85%) of 13 lesions were hyperechoic during the early phase, and the remaining 2 (15%) were isoechoic compared with surrounding parenchyma. Ten (77%) of 13 lesions remained either hyperechoic (5 of 13) or isoechoic (5 of 13) during the delay phase, whereas the remaining 3 lesions (23%) were hypoechoic. CONCLUSIONS: Contrast-enhanced gray scale harmonic sonography showed the typical vascularity of a spoked wheel pattern during the vascular phase and persistent enhancement on serial acoustic emission imaging in most cases of hepatic focal nodular hyperplasia, and thereby it can be a promising technique in noninvasive diagnosis of this entity.     

低杆温微波刀与冷循环射频消融在肝肿瘤治疗中的临床应用

目的探讨低杆温微波刀（cool-needle microwave coagulation treatment，MCT）与冷循环射频消融（cool-tipradiofrequency ablation，RFA）在恶性肝肿瘤治疗中的临床应用价值。方法超声引导下冷循环射频消融治疗原发性肝癌患者20例共22个病灶，而经超声引导下低杆温微波刀治疗原发性肝癌和肝转移癌19例共21个病灶，治疗前后经超声造影、增强CT或／和增强MRI检查明确诊断及评价疗效。结果22个病灶经一次RFA治疗后完全消融16个，5例经再次RFA后达完全消融；21个病灶经一次MCT治疗后16个达完全消融，4例经再次MCT治疗后达完全消融。两者一次完全消融率分别为72．7％（RFA）和76．2％（MCT），差异无统计学意义。结论低杆温MCT和冷循环RFA均能有效地原位灭活肝肿瘤，是有效的非手术治疗恶性肝肿瘤的方法之一。     

Contrast-enhanced three-dimensional fusion sonography of small liver metastases with pathologic correlation

PURPOSE: To demonstrate that liver metastases with a diameter of < or =40 mm show characteristic features on three-dimensional (3D) fusion sonographic images and that these sonographic findings can be correlated with histopathologic features of surgical specimens. METHODS: Liver metastases measuring < or =40 mm were examined via contrast-enhanced 3D fusion sonography. The characteristic sonographic findings of 17 tumor nodules in 11 patients with a histopathologically confirmed diagnosis of liver metastases were investigated, and their correspondence to the pathologic features were examined in 12 resected nodules. RESULTS: On sonograms, central vessels were visualized in all 17 tumor nodules and peripheral vessels were visualized in 12 nodules. On histopathologic examination, the portal triad vessels corresponded to the central vessels and were located at the center of the tumors. A thin layer of peritumoral hepatocytes showing various changes was also observed, and a group of tiny vessels were seen running along this layer of cells. CONCLUSIONS: Liver metastases measuring 40 mm or less in diameter were characterized by the presence of both central and peripheral vessels on contrast-enhanced 3D fusion sonography. There was good correlation between sonographic and histopathologic findings.     

Sonographic evaluation of early-stage breast cancers that undergo neoadjuvant chemotherapy.

OBJECTIVE: We prospectively evaluated low-stage breast cancers treated with neoadjuvant chemotherapy using whole-volume sonography and color Doppler imaging. METHODS: Thirty-four women with breast cancer (mean maximum size, 2.4 cm) received neoadjuvant chemotherapy with doxorubicin and docetaxel. Targeted whole-volume sonography of tumor sites was performed before and after chemotherapy to assess mass size, color pixel speed-weighted density, and American College of Radiology Breast Imaging Reporting and Data System sonographic characteristics. After chemotherapy, tumor sites were excised by lumpectomy or mastectomy. RESULTS: Three (11.3%) of 34 patients had a complete histologic response. After chemotherapy, correlation was r = 0.716 between final histologic and sonographic sizes. Compared with histologic residual tumors, sonography had 4 false-negative results, 3 false-positive results, and 27 true-positive results (sensitivity, 87%), with no false-negative results among a subgroup of tumors of 7 mm and larger (sensitivity, 100%). The 3 cases with false-positive results were histologic fibrosis or biopsy changes. Mean speed-weighted density was 0.015 before and 0.0082 after chemotherapy (P = .03). After chemotherapy, vascularity was less common within (P = .06) or adjacent to (P = .009) masses or in tumor sites (P = .05). Prechemotherapy variables of gray scale characteristics and vascularity were compared with final histologic size, and all had P > .20. CONCLUSIONS: Postchemotherapy sensitivity of sonography was high for residual tumors of 7 mm or larger. Correlation was moderate between histologic and sonographic final tumor sizes. False-positive results were caused by fibrosis or biopsy-related changes. False-negative results occurred with residual tumor size of 6 mm or smaller. After chemotherapy, vascularity usually decreased, and this was not specific for complete response. Before chemotherapy, no vascular or gray scale feature at initial imaging predicted complete responders.     

超声引导经皮微波消融治疗肾肿瘤

目的 探讨超声引导经皮微波消融肾肿瘤的安全性和临床疗效.方法 22例肾肿瘤患者(22个病灶),其中肾癌18例,肾血管平滑肌脂肪瘤3例,肾嗜酸细胞腺瘤1例.肿瘤直径1.0～3.8 cm.治疗时在超声引导下将水冷式微波天线植入肿瘤内,瘤周放置测温针实时监测温度,肿瘤直径小于2 cm者使用一根微波天线,肿瘤直径大于2 cm者使用2根微波天线.微波消融后3 d内行超声造影观察有无残存肿瘤,造影无肿瘤残存者治疗后1、3、6个月,随后每6个月行增强CT/MR或超声造影评价肿瘤的治疗效果.结果 20例病灶在一次消融后完全坏死,2例病灶在二次消融后完全坏死,微波消融无严重并发症出现,随访期内未发生肿瘤复发、转移.结论超声引导经皮微波消融肾肿瘤安全有效,副作用小,是治疗局限性肾肿瘤的有效方法.     

超声造影谐频成像对原发性肝癌治疗效果的评价

目的：评价超声造影谐频成像在原发性肝癌治疗后疗效判断方面的作用。方法：使用Levovist对27例33个肝癌结节治疗前后分别行超声造影能量多普勒谐频成像和灰阶谐频成像数字减影检查,结果与动态增强CT相比较。结果：以动态增强CT结果为金标准,治疗前33个肝癌结节,超声造影增强的阳性率为93．9％（31／33）;而对治疗后肝癌,能量多普勒成像显示肿瘤内血流信号的敏感性,特性和准确性均为100％,灰阶谐频成像数字减影则分别为93．9％、100％和96．8％,结论：超声造影谐频成像可以敏感而直观地显示治疗后肿瘤内残存的血流信号,即时评估肿瘤的治疗效果,创伤小,值得临床推广。