Characterization of a linear streak artifact with pulse inversion tissue harmonics in musculoskeletal sonography.

OBJECTIVE: To understand a linear artifact that projects deep to reflective structures that move rapidly while using tissue harmonic imaging with pulse inversion (PI) sonography. We hypothesize that this artifact is due to a cancellation error between firings in PI imaging, and it is, therefore, similar in generation to the twinkling artifact in color Doppler sonography. This artifact could be studied with the use of surfaces of different roughness to represent different rates of motion, in which roughness corresponds to spatial fluctuations in surface height. Given very slight variations in beam focusing as occurs with sonographic imaging arrays, these spatial fluctuations translate into temporal fluctuations in the received signal as would occur with tissue motion. METHODS: We scanned 4 different sandpaper grits and a smooth surface through a water path using fundamental and PI mode, 1- and 2-pulse techniques, respectively. The sandpaper and the smooth surface were scanned through a water path at mechanical indices of 0.1 to 0.7. Four independent images were subtracted pairwise to remove nonfluctuating signals. These noise pixels were counted and analyzed. RESULTS: Analysis of variance showed that the noise generated behind the different surfaces was highly significantly different. Two-tailed t tests generally showed significant differences in the quantity of noise between fundamental and harmonic imaging behind the roughest 3 grades of sandpaper. A multiple regression model showed significantly greater slopes for harmonic imaging for all grades of sandpaper and the smooth surface. CONCLUSIONS: The noise and, by extension, the linear streak artifact in musculoskeletal imaging are dependent on the mechanical index and are functions of sandpaper roughness. This would be equivalent to a subtraction error between 2 firings due to soft tissue motion, and the artifact may be a way to identify rapid soft tissue motion in PI images.     

Detection of cardiac right-to-left shunts by contrast-enhanced harmonic carotid duplex sonography.

OBJECTIVE: Paradoxical embolization by cardiac right-to-left shunts (RLS) is increasingly recognized as an important factor for embolic stroke. Contrast-enhanced transcranial Doppler sonography (ce-TCDS) is an established diagnostic tool for RLS detection but is frequently limited because of an inadequate temporal acoustic bone window. The purpose of this study was to determine whether extracranial sonography (ECS) using harmonic frequencies improves detection of RLS. METHODS: Extracranial color duplex sonography using harmonic frequencies enables visualization of even single ultrasound contrast agent microbubbles because of oscillation. Patients with stroke and positive RLS findings on transesophageal echocardiography underwent a simultaneous extracranial and transcranial sonographic examination of the proximal common carotid artery (CCA) and middle cerebral artery (MCA) on the same side. A Valsalva strain was performed for 10 seconds after intravenous bolus injection of a galactose-based nontranspulmonary contrast agent. The B-mode frame sequences of the transverse plane of the CCA obtained by harmonic ECS and the ce-TCDS recordings of high-intensity transient signals from the MCA were analyzed offline. RESULTS: In all patients with RLS, the shunts could be identified by harmonic ECS. A close correlation could be seen between the count of visualized microbubbles in the CCA and the number of high-intensity transient signals detected on ce-TCDS in the ipsilateral MCA. CONCLUSIONS: The results of this study indicate that contrast-enhanced ultrasound harmonic imaging of the CCA using a Valsalva strain might be an optional screening tool for detection of cardiac RLS in patients with insufficient acoustic bone windows.     

Color and pulsed Doppler sonography for arterial bleeding detection.

OBJECTIVE: Hemorrhage resulting from penetrating injuries in the extremities is the leading cause of preventable death in the modern battlefield. Development of methods for detection and localization of vascular bleeding is needed that could be applied emergently without special training outside the hospital setting. Our objective was to assess whether Doppler sonography can provide quantitative parameters that characterize the bleeding site in the extremities. METHODS: Twenty-four rabbit femoral arteries (diameter of approximately 1 mm) were punctured transcutaneously with an 18-gauge needle. Doppler interrogations were performed at 5 locations in the injured vessels (site of injury, distal and proximal locations relative to the injury, and neck and tip of the bleeding jet). RESULTS: Compared with the normal signals obtained before the vessel was punctured, pulsed Doppler observations of the injury site showed a statistically significant increase in the systolic and diastolic velocities (systolic: mean +/- SD, 30.1 +/- 12.5 cm/s [injury] versus 15.1 +/- 4.2 cm/s [normal]; diastolic: 17.8 +/- 6.5 cm/s [injury] versus 0.7 cm/s [normal]). Similar increases in velocities were observed at the neck of the bleeding jet, whereas the tip of the bleeding jet showed venouslike patterns. These patterns are unique only at the bleeding site. Color Doppler observations showed turbulence (in the form of checkered color patterns) localized at the injury site. CONCLUSIONS: Our results indicate that both color and pulsed Doppler sonography can be used to accurately localize the site of injury, which may facilitate application of hemorrhage control therapies in battlefield situations.     

Blunt hepatic trauma: evaluation with contrast-enhanced sonography: sonographic findings and clinical application.

OBJECTIVE: The purpose of this study was to report our initial experience in the assessment of liver trauma with real-time contrast-enhanced sonography (CES). METHODS: From January 2000 to December 2003, there were 431 hemodynamically stable patients evaluated with sonography for blunt abdominal trauma. Among these patients, 87 were selected to undergo second-level imaging, consisting of CES and computed tomographic (CT) evaluation. Indications for further assessment were baseline sonographic findings positive for liver injury, baseline sonographic findings positive for injury to other abdominal parenchyma, baseline sonographic findings positive for free fluid only, baseline sonographic findings indeterminate, and baseline sonographic findings negative with persistent clinical or laboratory suspicion. RESULTS: There were 23 hepatic lesions shown by CT in 21 patients. Peritoneal or retroperitoneal fluid was identified in 19 of 21 positive cases by all 3 imaging modalities. Liver injury was found in 15 patients on sonography and in 19 on CES. Contrast-enhanced sonography compared better than unenhanced sonography with the criterion standard for related injury conspicuity, injury size, completeness of injury extension, and involvement of the liver capsule. Both CES and CT showed intrahepatic contrast material pooling in 2 cases. All patients with false-negative sonographic or CES findings recovered uneventfully. CONCLUSIONS: Contrast-enhanced sonography is an effective tool in the evaluation of blunt hepatic trauma, being more sensitive than baseline sonography and correlating better than baseline sonography with CT findings. In institutions where sonography is regarded as the initial procedure to screen patients with trauma, this technique may increase its effectiveness. In addition, CES may be valuable in the follow-up of patients with conservatively treated liver trauma.     

Hepatic cyst with intracystic bleeding: contrast-enhanced sonographic findings

Intracystic bleeding is a relatively rare complication of hepatic cysts, which is very difficult to diagnose by conventional sonography (US). Hence, a new US technique has been sought for this purpose. We present the case of a hepatic cyst with intracystic bleeding in which contrast-enhanced US showed microbubbles oozing from the cyst wall into the cystic cavity. Contrast-enhanced US is now an important diagnostic tool for diagnosing liver tumors, but contrast-enhanced US findings relating to intracystic bleeding have not been reported. Our observations suggest that this technique may be a useful new diagnostic tool for this purpose.     

经阴道超声结合宫腔镜检查对绝经后子宫出血的诊断价值

目的探讨经阴道超声(TVS)结合宫腔镜(HSC)检查在绝经后子宫出血中的诊断价值。方法回顾性分析2007年6月至2010年6月应用TVS结合HSC检查绝经后子宫出血230例,术中行定位取材或诊断性刮宫。结果 TVS诊断绝经后子宫出血病人宫腔内病变的符合率为71.74%,TVS结合HSC的诊断符合率为88.26%。结论 TVS结合HSC对发现绝经后子宫出血病人宫腔内病变具有一定的价值。     

The role of late-phase pulse inversion harmonic imaging in the detection of occult hepatic metastases.

OBJECTIVE: The purpose of this study was to investigate the efficacy of late-phase pulse inversion harmonic imaging (PIHI) in detecting occult metastases and to compare the results with helical computed tomography (CT) in a group of patients whose fundamental liver sonographic results were normal. METHODS: Thirty-two patients (21 women and 11 men; age range, 20-87 years) with a known primary malignancy were enrolled in the study. The patients were evaluated with conventional sonography, unenhanced PIHI, and PIHI 3 minutes after the injection of Levovist (SH U 508A; Schering AG, Berlin, Germany). All patients also underwent triphasic helical CT within 1 week after sonography. In 1 patient, mangafodipir-enhanced magnetic resonance imaging was performed as part of the clinical workup. RESULTS: After Levovist injection, in 4 (12.5%) of 32 patients, at least 1 hypoechoic lesion was detected by PIHI; multiple lesions were shown in 1 patient. The mean diameter of newly detected lesions was 12 mm. Triphasic helical CT also showed all of the lesions that were detected by PIHI. The diagnoses were confirmed by biopsy and CT findings in 2 patients and by the typical CT and magnetic resonance imaging findings in 1 patient. For the fourth patient, the diagnosis was confirmed by follow-up and CT. Conclusions. Late-phase PIHI is comparable to helical CT for detecting occult hepatic metastases, but it protects patients from the potentially hazardous effects of radiation and iodinated contrast agents. Further series involving a larger number of patients are needed to determine its place in the evaluation of cancer staging and treatment planning.     

Characterization of portal vein thrombus with the use of contrast-enhanced sonography.

OBJECTIVES: To select an appropriate treatment regimen, it is essential to accurately characterize the nature of a thrombus. This study prospectively assessed the ability of contrast-enhanced sonography to differentiate between benign and malignant portal vein thrombosis in a population of high-risk patients. METHODS: Fifty-five patients (43 men and 12 women; mean age, 66 years; range, 55-83 years) with thrombi of the portal venous system were examined by power Doppler sonography and contrast-enhanced sonography with the intravenous contrast agent SH U 508A (Levovist; Schering AG, Berlin, Germany). Of the thrombi, 40 were characterized as malignant and 15 as benign. Pulsatile flow in the thrombus on power Doppler sonography and positive enhancement of the thrombus on contrast-enhanced sonography were judged as indications of a malignant thrombus. The sensitivity and specificity of both methods in differentiating the nature of the thrombus were evaluated. RESULTS: The detection of pulsatile flow in a portal vein thrombus as the criterion for diagnosing malignant portal vein thrombus yielded overall sensitivity of 82.5% and specificity of 100%, whereas positive enhancement of the portal vein thrombus itself as a criterion for diagnosing malignancy yielded overall sensitivity and specificity of 100% for each. CONCLUSIONS: Contrast-enhanced sonography can be helpful in discriminating between benign and malignant portal vein thrombi.     

Diagnostic Parameters to Differentiate Benign From Malignant Ovarian Masses With Contrast‐Enhanced Transvaginal Sonography

Objective. The aim of this study was to evaluate diagnostic parameters to differentiate between benign versus malignant ovarian masses using contrast‐enhanced transvaginal sonography (TVS). Methods. Thirty‐three consecutive patients with 36 morphologically abnormal ovarian masses (solid or cystic with papillary excrescences, focally thickened walls, or irregular solid areas) smaller than 10 cm received a microbubble contrast agent intravenously while undergoing pulse inversion harmonic TVS. The following parameters were assessed: presence of contrast enhancement, time to peak enhancement, peak contrast enhancement, half wash‐out time, and area under the enhancement curve (AUC). Tumor histologic analysis was used to distinguish benign from malignant ovarian tumors. Results. Twenty‐six benign masses and 10 malignancies were studied. Of all examined criteria, an AUC of greater than 787 seconds^?1 was the most accurate diagnostic criterion for ovarian cancer, with 100.0% sensitivity and 96.2% specificity. Additionally, peak contrast enhancement of greater than 17.2 dB (90.0% sensitivity and 98.3% specificity) and half wash‐out time of greater than 41.0 seconds (100.0% sensitivity and 92.3% specificity) proved to be useful. Conclusions. Our data suggest that the AUC, peak enhancement, and half wash‐out time had the greatest diagnostic accuracy for contrast‐enhanced TVS in differentiation between benign and malignant ovarian masses.     

Feasibility of contrast-enhanced sonography during resection of cerebral tumours: initial results of a prospective study

The aim of this study was to adapt the ultrasonographical techniques developed for brain perfusion imaging to an intraoperative setting for topographic diagnosis of cerebral tumours. During surgery, the patients underwent contrast-enhanced ultrasonography (phase inversion harmonic imaging, bolus kinetic, fitted model function). Endocavity curved array (6.5EC10, 6.5 MHz) was used intraoperatively. The ultrasound contrast agent SonoVue (Bracco) was administered IV as a bolus injection. Off-line, time-intensity curves as well as perfusion maps were calculated and parameters such as peak intensity were locally extracted to characterise perfusion. Seven patients with brain tumours of different histologic types were subjected to contrast-enhanced ultrasonography during surgery. Tissue differentiation with contrast agent was superior to conventional B-mode ultrasound imaging. Intraoperative contrast-enhanced ultrasonography enabled visualisation of cerebral tumours in high spatial resolution.     

Correlation between estimates of tumor perfusion from microbubble contrast-enhanced sonography and dynamic contrast-enhanced magnetic resonance imaging.

OBJECTIVE: We compared measurements of tumor perfusion from microbubble contrast-enhanced sonography (MCES) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in an animal tumor model. METHODS: Seven mice were implanted with Lewis lung carcinoma cells on their hind limbs and imaged 14 days later with a Philips 5- to 7-MHz sonography system (Philips Medical Systems, Andover, MA) and a Varian 7.0-T MRI system (Varian, Inc, Palo Alto, CA). For sonographic imaging 100 microL of a perfluoropropane microbubble contrast agent (Definity; Bristol-Myers Squibb Medical Imaging, Billerica, MA) was injected and allowed to reach a pseudo steady state, after which a high-mechanical index pulse was delivered to destroy the microbubbles within the field of view, and the replenishment of the microbubbles was imaged for 30 to 60 seconds. The MRI included acquisition of a T(10) map and 35 serial T(1)-weighted images (repetition time, 100 milliseconds; echo time, 3.1 milliseconds; alpha, 30 degrees ) after the injection of 100 microL of 0.2-mmol/kg gadopentetate dimeglumine (Magnevist; Berlex, Wayne, NJ). Region-of-interest and voxel-by-voxel analyses of both data sets were performed; microbubble contrast-enhanced sonography returned estimates of microvessel cross-sectional area, microbubble velocity, and mean blood flow, whereas DCE-MRI returned estimates of a perfusion-permeability index and the extravascular extracellular volume fraction. RESULTS: Comparing similar regions of tumor tissue seen on sonography and MRI, region-of-interest analyses revealed a strong (r(2) = 0.57) and significant relationship (P < .002) between the estimates of perfusion obtained by the two modalities. CONCLUSIONS: Microbubble contrast-enhanced sonography can effectively depict intratumoral heterogeneity in preclinical xenograft models when voxel-by-voxel analysis is performed, and this analysis correlates with similar DCE-MRI measurements.     

Splenic trauma: evaluation with contrast-specific sonography and a second-generation contrast medium: preliminary experience.

OBJECTIVE: To report our experience in the assessment of splenic trauma with contrast-coded sonography and a second-generation contrast medium. METHODS: From January to May 2002, 120 patients were studied with sonography for suspected splenic trauma. Twenty-five were selected for further imaging because of sonographic findings positive for splenic injury, findings positive for peritoneal fluid only, indeterminate findings, and negative findings with high clinical or laboratory suspicion. These patients underwent contrast-enhanced harmonic sonography and contrast-enhanced helical computed tomography. RESULTS: Among the 25 patients studied, 6 had no spleen trauma at initial and follow-up evaluation. One patient had a hypoperfused spleen without parenchymal damage, and 18 had splenic injuries; these 19 patients were considered positive. Hemoperitoneum was identified by sonography, contrast-enhanced sonography, and contrast-enhanced computed tomography in 74% of the 19 positive cases. Perisplenic clots were recognized in 58% of the cases by computed tomography and in 42% by baseline and enhanced sonography. Splenic infarctions were found in 11% of cases by contrast-enhanced sonography and computed tomography; none was found by unenhanced sonography. Parenchymal traumatic lesions were identified in 12 of 18 patients with splenic injuries by unenhanced sonography, in 17 cases by contrast-enhanced sonography, and in all 18 cases by contrast-enhanced computed tomography. A minimal splenic lesion was found in the single patient with a false-negative contrast-enhanced sonographic finding. Contrast-enhanced sonography correlated appreciably better than unenhanced sonography in detecting injuries and in estimating their extent. Findings undetectable on unenhanced sonography were also noted: splenic hypoperfusion in 11% of positive cases on both contrast-enhanced sonography and contrast-enhanced computed tomography, contrast medium pooling in 21% of cases on both contrast-enhanced sonography and computed tomography, and contrast extravasation in 11% of cases on computed tomography and 5% on contrast-enhanced sonography. CONCLUSIONS: Contrast-enhanced sonography is a promising tool in the assessment of splenic trauma. In institutions where sonography is used as the initial procedure, this technique may increase its effectiveness.     

彩色多普勒超声对食管胃底静脉曲张破裂出血危险性的判断价值

目的:探讨彩色多普勒超声(彩超)对门静脉高压患者食管胃底静脉曲张破裂出血危险性的判断价值。方法:根据43例门静脉高压食管胃底静脉曲张患者有无出血分为出血组19例和未出血组24例,另设健康对照组13名,将3组的彩超表现进行对比分析。结果:出血组、未出血组的门静脉充血分数分别为0.13±0.06、0.06±0.02,分别与对照组的0.034±0.015比较,均为P<0.01;出血组、未出血组的胃左静脉内径分别为(0.90±0.29)cm、(0.70±0.24)cm,分别与对照组的(0.31±0.07)cm比较,P<0.01、P<0.05;出血组和未出血组胃左静脉离肝血流速度分别为(14±6)cm/s、(11±6)cm/s,P>0.05;出血组和未出血组的食管曲张静脉内径分别为(0.52±0.12)cm、(0.34±0.11)cm,P<0.05;出血组与未出血组食管曲张静脉内血流速度分别为(19±8)cm/s、(11±6)cm/s,P<0.01。当门静脉充血分数为0.07时,其预测出血发生的敏感性为95%,特异性为86%。结论:门静脉充血分数、胃左静脉内径、食管曲张静脉内径及食管曲张静脉内血流速度对预测食管胃底静脉曲张破裂出血的危险性有价值。     

超声造影在妇科疾病中的应用及进展

超声造影技术近年来发展迅速,本文就该技术在妇科疾病中的应用和进展进行综述,重点介绍超声造影在鉴别卵巢良恶性肿瘤中的价值.超声造影在妇科其他方面的应用还包括子宫和输卵管疾病.     

Quantification of tumor vascularity with contrast-enhanced sonography: correlation with magnetic resonance imaging and fluorodeoxyglucose autoradiography in an implanted tumor.

OBJECTIVE: To correlate the quantitated tumor vascularity of implanted murine tumors as depicted by contrast-enhanced sonography with estimates made with magnetic resonance imaging and with estimates of the percentage of viable (metabolically active) tumor as depicted by fluorodeoxyglucose autoradiography. METHODS: Implanted tumors in 10 mice were imaged with contrast-enhanced sonography, magnetic resonance imaging, and fluorodeoxyglucose autoradiography. Tumor vascularity was estimated with each modality and compared with the percentage of viable tumor. RESULTS: Quantitated estimates of tumor vascularity with contrast-enhanced sonography closely correlated (r = 0.95) with estimates made by magnetic resonance imaging and with the percentage of viable tumor (r = 0.93) as depicted by fluorodeoxyglucose autoradiography. CONCLUSIONS: Contrast-enhanced sonography accurately depicts tumor vascularity in these implanted tumors. Tumor vascularity correlated with the amount of metabolically active tumor.     

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.     

Detection of metallic ocular foreign bodies with handheld sonography in a porcine model.

OBJECTIVE: Eye conditions are common in emergency departments. Intraocular foreign bodies (IOFBs) are a frequent concern. Orbital computed tomography (CT) is traditionally used for evaluation. We sought to evaluate bedside ocular sonography for detecting metallic IOFBs. METHODS: A pig model was chosen. A micrometer was used to create 3 precise metallic fragments: 0.012 x 0.012 x 0.012, 0.025 x 0.025 x 0.012, and 0.05 x 0.05 x 0.012 in. Individual eyes were randomized to the presence or absence of a foreign body. Randomization was also used to determine the specific size of any given IOFB. A standard 18-gauge spinal needle was used to puncture the sclera and introduce the IOFB into the vitreous. Each eye was then evaluated by 2 sonologists for the presence or absence of an IOFB. RESULTS: A total of 28 eyes were used; 12 (43%) were randomized to no IOFB and 16 (57%) to the presence of an IOFB. Of the 16 eyes that received IOFBs, 8 (50%) were 0.012 x 0.012 x 0.012 in; 5 (31%) were 0.025 x 0.025 x 0.012 in; and 3 (19%) were 0.05 x 0.05 x 0.012 in. Sensitivity was 87.5% and specificity 95.8%. Positive predictive value (PPV) and negative predictive value (NPV) were 96.5% and 85.2%, respectively. CONCLUSIONS: Bedside sonography may identify the presence of metallic IOFBs. The PPV allows a high degree of certainty that an IOFB is actually present if seen and may negate the need for uninfused orbital CT. The NPV was 85.2%. Given the potential grave consequences of a missed IOFB, sonography cannot be used as the definitive test to rule out the presence of a metallic IOFB. In the presence of negative findings, further imaging is warranted.     

Tissue harmonic imaging: utility in breast sonography.

OBJECTIVE: To determine the impact of tissue harmonic imaging on visualization of focal breast lesions and to compare gray scale contrast between focal breast lesions and fatty tissue of the breast between tissue harmonic imaging and fundamental frequency sonography. METHODS: A prospective study was performed on 219 female patients (254 lesions) undergoing sonographically guided fine-needle biopsy. The fundamental frequency and tissue harmonic images of all lesions were obtained on a scanner with a wideband 7.5-MHz linear probe. Twenty-three breast carcinomas, 6 suspect lesions, 9 fibroadenomas, 1 papilloma, 1 phyllodes tumor, 162 unspecified solid benign lesions, and 40 cysts were found. In 12 cases the fine-needle aspiration did not yield sufficient material. The gray scale intensity of the lesions and adjacent fatty tissue was measured with graphics software, and the gray scale contrast between lesions and adjacent fatty tissue was calculated. RESULTS: Tissue harmonic imaging improved the gray scale contrast between the fatty tissue and breast lesions in 230 lesions (90.6%; P < .001) compared with fundamental frequency images. The contrast improvement was bigger in breasts with predominantly fatty or mixed (fatty/glandular) composition than in predominantly glandular breasts. The overall conspicuity, lesion border definition, lesion content definition, and acoustic shadow conspicuity were improved or equal in the harmonic mode for all lesions.CONCLUSIONS: The tissue harmonic imaging technique used as an adjunct to conventional breast sonography may improve lesion detectability and characterization.     

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.     

Phase inversion harmonic imaging improves assessment of renal calculi: a comparison with fundamental gray-scale sonography

PURPOSE: To compare phase inversion harmonic imaging (PIHI) with fundamental imaging (FI) in the evaluation of renal calculi. METHODS: Thirty adult patients with renal calculi (17 men, 13 women; mean age 44 years [range, 25-71]) underwent transabdominal sonographic examination of the urinary system. Both kidneys and renal calculi were examined with PIHI and FI. Overall renal conspicuity, calculus visibility, and clarity of posterior shadowing were assessed subjectively using a 4-point scale (0 being the worst, 3 being the best). The maximum diameter of the calculi was measured using both techniques. The effect of body mass index on qualitative scoring and quantitative measurements was evaluated. RESULTS: PIHI improved overall renal conspicuity compared with FI (p < 0.001). The visibility of the calculi and clarity of posterior shadowing were significantly better with PIHI than with FI (p < 0.001 for both parameters). The maximum diameter of calculi was larger with PIHI than with FI (p < 0.001). The superiority of PIHI over FI regarding overall conspicuity of the kidney, visibility of the calculus, and clarity of posterior shadowing scores increased in the obese group (p < 0.001 for all 3 parameters). The mean calculus diameter difference between the 2 techniques was significantly higher in the obese group. CONCLUSION: The routine use of PIHI is recommended in the evaluation of renal calculi.