Hepatocellular carcinoma: assessment of vascularity with single-level dynamic ultrasonography during the arterial phase.

OBJECTIVE: To evaluate the hemodynamic features of hepatocellular carcinoma on single-level dynamic ultrasonography during the arterial phase. METHODS: Twenty-two hepatocellular carcinomas were examined by single-level dynamic ultrasonography with high transmit intensity and SH U 508A. The scans were performed for 40 seconds with a 1-second interval between each ultrasound transmission and with individual optimization of the scan delay time. The times of initiation of enhancement for both the hepatic artery and the tumor and the time of maximal enhancement for the tumor were recorded, and the mean echo values at every second for the tumor and hepatic parenchyma were measured. RESULTS: Twelve tumors showed hyperechoic enhancement compared with hepatic parenchyma throughout the scans. The other 10 showed hyperechoic enhancement during some segments (range, 8-34 seconds) and either isoechoic (n = 5) or hypoechoic (n = 5) enhancement during the remaining parts; the hyperechoic segments were often short (< 20 seconds, 14%). Although the times for initiation of enhancement for the hepatic artery and hepatocellular carcinoma and the time of maximal enhancement for the tumor varied, the tumor usually initiated enhancement immediately after the hepatic artery (r = 0.986; P = .000001). The interval between the time of initiation of enhancement for the tumor or hepatic artery and that of maximal enhancement for the tumor was significantly correlated with the tumor size (r = 0.700; P = .008; and r = 0.780; P = .002). CONCLUSIONS: With individual optimization of the scan delay time, single-level dynamic ultrasonography is useful for depicting the hypervascularity of hepatocellular carcinoma during the arterial phase.     

Impact of contrast-enhanced ultrasonography in a tertiary clinical practice.

OBJECTIVE: The purpose of this study was to assess the impact of contrast-enhanced ultrasonography (CEUS) of the liver in a tertiary clinical practice. METHODS: One thousand forty consecutive CEUS examinations performed over 30 months for mass characterization were reviewed to determine their source, accuracy, and clinical impact. RESULTS: Two hundred seventy-five (26.4%) of 1040 examinations were motivated by incidental detection of a mass at routine ultrasonography; 765 (73.6%) were clinical referrals, most often for characterization of a mass in a high-risk patient scanned for hepatoma surveillance or characterization of an indeterminate mass after prior imaging. Clinician referrals increased from 57 in the first 6 months after CEUS introduction to 158 in the last 6 months of the study. Surveillance scans yielded 78 confirmed hepatocellular carcinomas characterized on CEUS at the time of identification. Contrast-enhanced ultrasonography was accurate in 233 (89.2%) of 261 with histologic proof, including 208 malignant lesions. Clinical impact included reduced referrals for other imaging in 226 (21.7%) of 1040 patients, decreased time to diagnosis in 390 (37.5%), and successful guidance for ablation therapy in 26 (2.5%). A positive change in management occurred in 182 (17.5%) of 1040, including alteration of a previous diagnosis, a diagnosis made by CEUS after indeterminate prior imaging, and a diagnosis upstaged by CEUS. Negative impacts included delayed management in 8 (0.8%) small hepatocellular carcinomas misdiagnosed as benign lesions and wrong management of a solitary sclerotic hemangioma, in a high-risk patient for hepatoma, misdiagnosed as a malignant tumor on CEUS, computed tomography, and magnetic resonance imaging, leading to its surgical removal. CONCLUSIONS: Contrast-enhanced ultrasonography has a positive impact on clinical management, providing rapid, accurate diagnosis of incidentally detected masses and resolving nodules on surveillance scans and indeterminate masses on other imaging.     

Characterization of focal liver lesions: comparison of pulse-inversion harmonic contrast-enhanced sonography with contrast-enhanced CT

PURPOSE: To compare the efficacy of contrast-enhanced pulse-inversion harmonic sonography for the characterization of focal liver lesions with that of contrast-enhanced helical CT. METHODS: Real-time contrast-enhanced sonography (CEUS) using Sonovue and contrast-enhanced CT (CECT) were performed on 109 patients with focal liver lesions, including 61 hepatocellular carcinomas, 15 liver metastases, 5 cholangiocellular carcinomas, 12 hemangiomas, 5 regenerative nodules, 3 adenomas, 3 focal nodular hyperplasias, 4 focal necroses, and 1 angiomyolipoma prior to surgery or percutaneous needle biopsy. The diagnostic performance was assessed by using histopathological results as reference standards. RESULTS: Three cases were missed on CEUS, and 7 cases were missed on CECT. These 10 missed cases were excluded from paired statistical comparison. Ten cases were misdiagnosed on CEUS and 17 cases were misdiagnosed on CECT. The overall accuracy was 89.9% (89/99) for CEUS and 82.8% (82/99) for CECT. The difference between CEUS and CECT was not statistically significant. Concordance between CEUS and CECT was observed in 90.9% (90/99) cases. CONCLUSION: Real-time pulse-inversion harmonic CEUS with Sonovue is comparable with CECT in the characterization of focal liver lesions.     

Diagnosis of focal liver masses on ultrasonography: comparison of unenhanced and contrast-enhanced scans.

OBJECTIVE: The purpose of this study was to compare the diagnostic accuracy, confidence level, and recommended management of focal liver masses after contrast-enhanced ultrasonography (CEUS) compared with unenhanced ultrasonography alone. METHODS: One hundred sixty-seven patients were referred for CEUS to characterize a focal liver mass. A 2-person blind read determined benignancy or malignancy, comparative diagnosis, and accuracy on both ultrasonography and CEUS. Results were compared with the final diagnoses. RESULTS: The 2 readers could not determine benignancy or malignancy in 77 (46.1%) and 46 (27.5%) of 167 unenhanced scans compared with 2 (1.2%) and 1 (0.6%) of 167 CEUS scans. The confidence level increased from 0 responses in the 2 highest grades (4 and 5) on the unenhanced scans to 135 (81.8%) and 132 (79.5%) of 167 at level 5 for CEUS. Regarding the diagnosis, the confidence level was lowest (grade 1) on the unenhanced scans in 128 (82.1%) and 79 (65.3%) of 167 for the 2 readers and improved to the highest (grade 5) in 110 (65.9%) and 113 (68.1%) of 167. Regarding diagnostic accuracy, the unenhanced scans agreed with the correct diagnosis in 85 (50.9%) and 63 (37.7%) of 167, and CEUS agreed with the correct diagnosis in 133 (79.6%) and 142 (85%) of 167 for readers 1 and 2, respectively. Recommendations for further imaging decreased from 166 (99.4%) and 147 (88%) of 167 on the unenhanced scans to 30 (18%) and 5 (3%) of 167 on CEUS for readers 1 and 2. CONCLUSIONS: Contrast-enhanced ultrasonography improves the accuracy and confidence of diagnosis of focal liver lesions and reduces recommendations for further investigations.     

Imaging of focal liver lesions: low-mechanical-index real-time ultrasonography with SonoVue.

OBJECTIVE: The purpose of this study was to evaluate the usefulness of a contrast-enhanced contrast-specific ultrasonographic technique with a low mechanical index for characterization of focal liver lesions. METHODS: Contrast-specific ultrasonography was used to assess 144 patients with 147 focal liver lesions: 87 primary liver carcinomas, 27 hemangiomas, 16 focal nodular hyperplasias, 5 hepatic abscesses, 3 inflammatory pseudotumors of the liver, and 9 metastases. A sulfur hexafluoride gas-based contrast agent was used with a mechanical index of 0.08 to 0.11. RESULTS: On contrast-enhanced ultrasonography, the typical hemodynamic pattern of primary liver carcinoma was the whole-lesion enhancement or mosaic enhancement in the arterial phase with an enhancement defect in the late phase (sensitivity, 92.0%; specificity, 86.7%). The most common enhancement pattern of hemangioma was that enhancement appeared in the periphery first and progressively filled into the lesion center (sensitivity, 96.3%; specificity, 97.5%). The enhancement pattern of focal nodular hyperplasia was that the whole lesion enhanced early and rapidly in the arterial phase with a centrifugal radiating configuration and appeared isoechoic or hyperechoic until the late phase (sensitivity, 87.6%; specificity, 94.5%). The central scar was detected in 31.3% of cases in the late phase. The specific enhancement of a hepatic abscess was the honeycomblike enhancement in all phases (sensitivity, 80.0%; specificity, 100%). No enhancement of a lesion in all phases was specific for an inflammatory pseudotumor of the liver. CONCLUSIONS: Contrast-enhanced real-time ultrasonography is a promising approach in the noninvasive characterization of focal liver lesions and can be useful as a first-line imaging technique clinically when a focal liver lesion is detectable on ultrasonography.     

Contrast-enhanced multiphase dynamic ultrasonography for the characterization of liver tumors

Purpose The purpose of the study was to introduce our protocol for contrast-enhanced multiphase dynamic ultrasonography (US) and examine the effectiveness of this method for characterizing liver tumors.Methods The subjects were 142 patients with liver tumors. The final diagnoses were 58 hepatocellular carcinomas (HCCs), 4 cholangiocellular carcinomas (CCCs), 14 metastases, 29 hemangiomas, 6 cases of focal nodular hyperplasia (FNH), and 31 other benign lesions. The contrast agent used was Levovist. A wide-band pulse inversion harmonic imaging mode was employed. Multiphase dynamic US was achieved by changing the sound transmission interval automatically from 0.3 s to 15.0 s according to a preset menu. Early arterial-phase images were observed at the short interval, and an equilibrium-phase image was observed at the longest interval. After a series of vascular images, a postvascular liver parenchymal image was obtained. Based on previously published criteria, the most compatible diagnosis was noted. The accuracy of this multiphase dynamic US technique for diagnosing focal liver lesions was examined by comparing our results with the final diagnosis based on a prospective study.Results The overall accuracy of all 142 cases was 93.7%. The sensitivity, specificity, and positive predictive value were, respectively, 100%, 92.9%, and 90.6% for HCC; 88.9%, 97.6%, and 84.2% for metastasis or CCC; 89.7%, 100%, and 100% for hemangioma; and 83.3%, 100%, and 100% for FNH.Conclusion Contrast-enhanced multiphase dynamic US is a highly accurate, safe diagnostic tool for characterizing liver tumors.     

Visualization of uveal perfusion by contrast-enhanced harmonic ultrasonography at a low mechanical index: a pilot animal study.

OBJECTIVE: To evaluate contrast-enhanced harmonic ultrasonography at a low mechanical index for its usefulness in visualizing uveal perfusion. METHODS: The study was performed with 9 rabbits, 6 intact and 3 with focal impaired blood flow in the uvea. Ultrasonography was performed by harmonic imaging (transmit, 5 MHz; receive, 10 MHz) with a contrast agent. The agent was administered at a dose of 50 microL/kg. Transmission power was at a mechanical index of 0.2, which is below the US Food and Drug Administration guideline. The images were compared between the impaired and intact eyes. For uveal measurements, video signal intensity-versus-time plots were generated in all cases. The plots were analyzed to obtain the rate of signal intensity increase and peak signal intensity. RESULTS: A clear increase of signal intensity was observed after contrast agent administration. The signal intensity of the uvea was lower in the impaired eye than in the intact eye. In the impaired eye, the intensity was lower on the side with impaired flow than on the other side. The differences were significant. CONCLUSIONS: Our findings suggest that uveal perfusion can be visualized by contrast-enhanced harmonic ultrasonography in the harmonic imaging mode at a low mechanical index.     

Evaluation of lymph node perfusion using continuous mode harmonic ultrasonography with a second-generation contrast agent.

OBJECTIVE: To evaluate the contribution of continuous mode contrast-enhanced harmonic ultrasonography (CE-HUS) with a second-generation contrast agent to the characterization of superficial lymphadenopathies with respect to conventional ultrasonographic techniques (B-mode and power Doppler). METHODS: Fifty-six lymph nodes from 45 patients were studied both by conventional techniques and by CE-HUS. The dimensions, intranodal architecture, margins, and location of vessels were evaluated. Subsequently, all the lymph nodes were examined by CE-HUS, and enhancement of echogenicity was evaluated. The diagnoses obtained by means of fine-needle aspiration cytologic examination, surgical biopsy, or both were compared with those obtained by ultrasonography. RESULTS: Of the lymph nodes examined, 30 were benign and 26 were malignant (18 metastases and 8 non-Hodgkin lymphomas). The study using CE-HUS showed intense homogeneous enhancement in 28 of 30 reactive lymph nodes; perfusion defects in 17, of which 15 were neoplastic and 2 were inflammatory; intense but inhomogeneous speckled enhancement in the early arterial phase in 5 cases of lymphoma; and, last, scarce or absent intranodal enhancement in 4 metastases. The specificity, sensitivity, and accuracy of conventional techniques in differentiation between benign and malignant lymph nodes were 76%, 80%, and 78% versus 93%, 92%, and 92.8% for CE-HUS. The increase in correct diagnoses was significant (P = .05) when conventional ultrasonography was tested against CE-HUS. CONCLUSIONS: Superficial lymph nodes can be characterized as being neoplastic or benign with a high degree of diagnostic accuracy on the basis of the perfusion characteristics evaluated by CE-HUS. This technique has been shown to afford a higher degree of accuracy than currently obtainable by any other ultrasonographic technique.     

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.     

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.     

肝良恶性肿瘤超声造影定量分析的对比研究

目的 探讨超声造影技术对肝良恶性肿瘤的鉴别诊断价值.方法 应用超声造影技术检查91例肝肿瘤患者(良性肿瘤37例43个病灶,恶性肿瘤54例79个病灶),观察注射造影剂SonoVue后良恶性肿瘤结节的血流灌注特征,绘制时间一强度曲线,分析曲线的形态特征及定量参数变化.结果 肝血管瘤的增强造影表现为"慢进慢出",肝硬化结节和不均性脂肪肝的增强与肝实质同步;肝恶性肿瘤表现为"快进快出".肝良性肿瘤的时间一强度曲线呈单峰或多峰,上升支及下降支多缓慢且部分有转折;恶性肿瘤的曲线呈单峰,上升支陡峭,成角明显,下降支相对缓慢.良恶性肿瘤的始增时间(14.19±6.26)s vs(10.36±2.80)s、峰值时间(51.33±25.76)s vs(20.88±5.71)s、斜率(0.08±0.03)vs(0.19±0.28)、增强速率(0.67±0.69)dB/s vs(1.86±0.95)dB/s比较,差异均有统计学意义(P＜0.05).结论 超声造影能动态显示肝肿瘤不同时相的增强情况,定量分析肝肿瘤时间一强度曲线能明显提高超声对肝肿瘤定性诊断率.     

肾细胞癌常规超声及超声造影特征

目的 观察肾细胞癌（RCC）及其常见病理亚型的常规超声及超声造影（CEUS）特征。方法 纳入94例RCC（恶性组）及34例肾脏良性病变患者（良性组）,将恶性组分为肾透明细胞癌（ccRCC）亚组（n=74）和肾乳头状细胞癌（pRCC）及肾嫌色细胞癌（cRCC）亚组（n=16）;比较良、恶性组及恶性组2亚组病灶常规超声及CEUS特征。结果 恶性组主要表现为低回声（63/94,67.02%）、快进（84/94,89.36%）、快退（58/94,61.70%）及高增强（68/94,72.34%）,良性组主要表现为高回声（20/34,58.82%）、快进（22/34,64.71%）、慢退（16/34,47.06%）及高增强（15/34,44.12%）;组间病灶回声、CEUS增强方式、消退方式及增强强度差异均有统计学意义（P均<0.05）。恶性组内2亚组病灶增强程度差异具有统计学意义（P<0.05）,ccRCC主要表现为高增强（61/74,82.43%）,pRCC及cRCC主要表现为低增强（10/16,62.50%）。结论 RCC,尤其ccRCC超声多表现为低回声、快进、快退及高增强;常规超声及CEUS对术前诊断RCC有一定价值。     

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.     

Malignant focal liver lesions at contrast-enhanced ultrasonography and magnetic resonance with hepatospecific contrast agent

The aim of this study was to compare the diagnostic accuracy of the late phase of CEUS and the hepatobiliary phase of CE-MR with Gd-BOPTA in the characterization of focal liver lesions in terms of benignity and malignancy. A total of 147 solid focal liver lesions (38 focal nodular hyperplasias, 1 area of focal steatosis, 3 regenerative nodules, 8 adenomas, 11 cholangiocarcinomas, 36 hepatocellular carcinomas and 49 metastases) were retrospectively evaluated in a multicentre study, both with CEUS, using sulphur hexafluoride microbubbles (SonoVue, Bracco, Milan, Italy) and CE-MR, performed with Gd-BOPTA (Multihance, Bracco, Milan, Italy). All lesions thought to be malignant were cytohistologically proven, while all lesions thought to be benign were followed up. Sensitivity, specificity, positive (PPV) and negative (NPV) predictive values and accuracy were calculated for the late phase of CEUS and the hepatobiliary phase of CE-MRI, respectively, and in combination. Analysis of data revealed 42 benign and 105 malignant focal liver lesions. We postulated that all hypoechoic/hypointense lesions on the two phases were malignant. The diagnostic errors were 13/147 (8.8%) by CEUS and 12/147 (8.2%) by CE-MR. Sensitivity, specificity, PPV, NPV and accuracy of the late phase of CEUS were 90%, 93%, 97%, 80% and 91%, 93%, 97%, 81% and 92% for the hepatobiliary phase of CE-MRI, respectively. If we considered both techniques, the misdiagnosis diminished to 3/147 (2%) and sensitivity, specificity, PPV, NPV and accuracy were 98%, 98%, 99%, 95% and 98%. The combination of the late phase of CEUS and the hepatobiliary phase of CE-MR in the characterization of solid focal liver lesions in terms of benignity and malignancy is more accurate than the two techniques used separately.     

Primary carcinoid tumor of the liver: report of a case with an emphasis on contrast-enhanced ultrasonographic findings

We report the case of a 82-year-old man with primary carcinoid tumor of the liver. Abdominal ultrasonography (US) showed 2 well-demarcated, round tumors in the right lobe (4 x 4 cm and 1 x 1 cm). The lesions were both markedly echogenic with many small cystic areas. Contrast-enhanced US showed the whole tumor to be quickly and highly enhanced, suggesting the highly vascular nature of the lesion, and the findings corresponded well with hepatic angiographic results. The patient underwent a US-guided needle biopsy, which yielded histological results consistent with a carcinoid tumor. Considering his age, we selected radiofrequency ablation (RFA) for treatment. After treatment, contrast-enhanced US demonstrated complete disappearance of blood flow signals, indicating satisfactory treatment. Our case showed that US and contrast-enhanced US findings can lead to a high suspicion of carcinoid tumor.     

Value of contrast-enhanced power Doppler sonography using a microbubble echo-enhancing agent in evaluation of small breast lesions

PURPOSE: The purpose of this study was to prospectively evaluate the usefulness of contrast-enhanced power Doppler sonography (PDUS) using a microbubble echo-enhancing agent in differentiating between malignant and benign small breast lesions. PATIENTS AND METHODS: Between July 1, 2000, and September 30, 2001, we performed gray-scale sonographic examination of patients in whom diagnostic sonography or screening mammography had revealed solid breast lesions measuring less than 2 cm in the largest dimension. The patients were then examined on PDUS before and after injection of a microbubble contrast agent. The sonographic findings for all 3 techniques, as well as the morphologic features of the Doppler signals for each patient before and after injection of the contrast agent on PDUS, were independently assessed. Each lesion was classified as "benign" or "malignant" on the basis of specific criteria for sonographic interpretation. A hemodynamic study was performed in which time-transit profiles of the Doppler signals on contrast-enhanced PDUS were generated using a computer-assisted program, and the results for each patient were compared with the findings of a histopathologic examination of surgical specimens. RESULTS: Thirty-six patients (35 women and 1 man) with a mean age of 43.5 years (range, 18-69 years) were evaluated. The tumors ranged from 4 to 19 mm in the largest dimension. Histopathologic examination revealed that 19 tumors were benign and 17 were malignant. For morphologic diagnosis of the malignant lesions, the sensitivity of gray-scale sonography was 100%, compared with 29% for PDUS without contrast enhancement. The specificity of gray-scale sonography was 47%, compared with 74% for PDUS without contrast enhancement. Contrast-enhanced PDUS had a sensitivity of 71% and a specificity of 58%. The diagnostic accuracy was 72% for gray-scale sonography, 53% for PDUS without contrast enhancement, and 64% for contrast-enhanced PDUS. The time-transit profiles of the hemodynamic study did not reveal a statistically significant difference in the accuracy rates of contrast-enhanced PDUS between benign and malignant breast lesions. CONCLUSIONS: Compared with PDUS without contrast enhancement, contrast-enhanced PDUS provides better visualization of the morphology of vascular Doppler signals that is characteristic of malignancy and therefore has a higher sensitivity and diagnostic accuracy, albeit a lower specificity. In differentiating between benign and malignant small breast lesions, contrast-enhanced PDUS can be helpful when used with gray-scale sonography and PDUS without contrast enhancement.     

肝血管平滑肌脂肪瘤的临床及超声造影特点分析:与肝血管瘤及肝细胞癌对比

目的 对比分析肝血管平滑肌脂肪瘤（HAML）与肝血管瘤（HCH）及肝细胞癌（HCC）的临床及超声特点。方法 回顾性分析经病理证实的40例HAML患者（HAML组），并与同时期随机检索的40例HCH患者（HCH组）及40例HCC患者（HCC组），比较其临床特点、二维超声和超声造影表现。结果 HAML好发于女性（70.00%，28/40），平均发病年龄（39.8±10.6）岁，在患者性别、年龄、肝炎病毒感染方面均与HCC差异有统计学意义（P均<0.001），而与HCH差异无统计学意义（P均>0.05）。HAML二维超声多表现为边界清楚的高回声病灶。HAML组与HCC组间回声（χ²=8.93，P=0.008）、边界（χ²=2.03，P=0.013）差异均有统计学差异，病灶数目、大小、形态及血供差异均无统计学意义（P均>0.05）；与HCH组间病灶数目、大小、边界、回声、形态及血供差异均无统计学意义（P均>0.05）。62.50%（25/40）的HAML病灶CEUS表现为"快进快退"模式，但与HCC组相比在强化消退为等增强（t=-2.46，P=0.016）及低增强的时间（t=-5.35，P<0.001）方面差异均有统计学意义。HAML组与HCH组间、HAML组与HCC组间门脉期及延迟期增强表现差异均有统计学意义（P均<0.05），而动脉期增强表现差异均无统计学意义（P均>0.05）。结论 结合临床特点、二维超声和超声造影表现，有助于诊断HAML，并与HCH、HCC相鉴别。