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PubMed2004

Real-time three-dimensional myocardial contrast echocardiography in assessment of myocardial perfusion defects.

BACKGROUND: Both real-time three-dimensional echocardiography (RT3DE) and myocardial contrast echocardiography (MCE) are novel imaging techniques. The purpose of this study was to confirm the feasibility and accuracy of RT3DE combined with MCE for quantitative evaluation of myocardial perfusion defects. METHODS: Thirteen dogs underwent ligation of the left anterior descending artery (LAD, n = 6) or distal branch of the left circumflex artery (LCX, n = 7) under general anaesthesia. Three to four ml of a perfluoropropane (C3F8) microbubble contrast agent was injected intravenously to assess the resulting myocardial perfusion defects with a commercially available Philips SONOS-7500 ultrasound system. After removal of the dog hearts, Evans blue dye was injected via the left and right coronary arteries to stain the myocardium at risk. In vitro anatomic measurements of myocardial mass after removal of the animals' hearts were used as controls. RESULTS: Left ventricular (LV) mass determined by RT3DE ranged 36.7 - 68.9 g [mean, (54.6 +/- 9.6) g] before coronary artery ligation, and correlated highly (r = 0.99) with in vitro measurement of LV mass [range, 38.9 - 71.1 g; mean, (55.6 +/- 9.3) g]. There was no significant difference between RT3DE and in vitro measurements of LV mass [range, 36.7 - 68.9 g; mean, (51.3 +/- 12.5) g. Or range, 38.9 - 71.1 g; mean, (53.7 +/- 12.3) g, respectively] and under-perfused mass [range, 0 - 21.4 g; mean, (12.0 +/- 6.9) g. Or range, 0 - 19.8 g; mean, (10.8 +/- 6.3) g, respectively] after the LAD ligation (P > 0.05). Likewise, no significant difference was present between RT3DE and in vitro measurements of LV mass [range, 50.1 - 65.4 g; mean, (57.5 +/- 5.9) g. Or range, 51.5 - 65.8 g; mean, (57.3 +/- 6.4) g, respectively] and under-perfused mass [range, 0 - 25.6 g; mean, (13.3 +/- 9.6) g. Or range, 0 - 22.7 g; mean, (12.8 +/- 8.1) g, respectively] after the LCX ligation (P > 0.05). For all the animals with coronary ligation, LV mass measured by RT3DE ranged 35.9 - 68.6 g [mean, (54.8 +/- 10.0) g] and there was no significant difference between RT3DE and in vitro measurements of LV mass and under-perfused mass (P > 0.05, r = 0.99). Further, the under-perfused mass derived from RT3DE [range, 0 - 25.6 g; mean, (12.7 +/- 8.2) g] correlated strongly with the in vitro measurements [range, 0 - 22.7 g; mean, (11.9 +/- 7.2) g] (r = 0.96). CONCLUSION: RT3DE with MCE is a rapid and accurate method for estimating LV myocardial mass and quantifying perfusion defects.

Animals↗

PubMed1992

Transesophageal echocardiographic evaluation of aortic valve integrity with antegrade crystalloid cardioplegic solution used as an imaging agent.

Forceful intravascular injection of crystalloid causes microbubble (cavitation) formation. The resulting ultrasound-opaque medium is widely used in echocardiography as a source of contrast. The following study was performed to determine the feasibility of using antegrade crystalloid cardioplegic solution as a transesophageal two-dimensional echocardiographic imaging agent to evaluate aortic valve integrity. In patients with preexisting aortic regurgitation (n = 12), cardioplegic solution administration (driving pressure 150 to 200 mm Hg) was associated with the appearance of intracardiac cavitations in 12 of 12 patients. Among patients without preexisting valve dysfunction (n = 22), intracardiac cavitations were manifested in 20 of 22, with extension of the cavitations to the left atrium in 17. Associated cardiac dimensions (left ventricular outflow tract area and left ventricular diameter) did not exceed preceding cardiopulmonary bypass values in these patients (2.0 +/- 1.6 cm2 versus 2.6 +/- 1.2 cm2 and 1.4 +/- 0.7 cm versus 1.5 +/- 0.8 cm, respectively). It was concluded that antegrade crystalloid cardioplegic solution can be used as an echocardiographic contrast agent in this context. The inability to establish a relationship between the extent of cardioplegic intracardiac penetration and left ventricular dimensional changes limits the technique, as presently employed, to qualitative analysis of valve dysfunction.

Adult↗

PubMed2004

[Sclerosing treatment of vascular malformations].

Traditional sclerotherapy with liquid sclerosants has been used for many years in the treatment of venous, lymphatic and low flow vascular malformations; it is efficient only with those vascular malformations of reduced size as a pre or post-operational complement. The use of liquid sclerosants has the limitations of their dilution and progressive inactivation in a great haematic volume, the irregular distribution of the sclerosant on the endothelium, the handling of the sclerosant once injected and its imperceptibility to the echo-Doppler. In their turn, both ethanol and sodium morrhuate - the most habitually employed sclerosants - produce important secondary effects. On the contrary, the use of sclerosants, specifically polidocanol in microfoam form, significantly improves the procedure, since the microfoam displaces the blood instead of mixing and diluting itself in it, thus facilitating an homogeneous distribution of the sclerosant over the endothelial surface. Finally, the echogenicity of the microbubbles, which makes them directly visible, together with their manageable consistency, means that it can be distributed more easily throughout the treated area. We comment on our experience with 50 patients with venous or low flow vascular malformations, treated with this new form of sclerosant. Similarly, the use of OK-432 (picibanil) - as the recommended sclerosant treatment in lymphatic vascular, especially macrocystic, malformations - is reviewed and its protocol given.

Blood Vessels↗

PubMedDate not supplied

[Myocardial contrast: scopes and limits].

Myocardial contrast echocardiography is an noninvasive and promising method for the assessment of myocardial perfusion. At the beginning, the contrast agents were administered intracoronary but now the second-generation contrast agents contain microbubbles that traverse the pulmonary circulation and opacity the myocardium after intravenous injection of contrast. The sensitivity, specificity and diagnostic accuracy of myocardial contrast is comparable with perfusion nuclear studies. The myocardial contrast echocardiography is currently the best and most accurate measure of reperfusion at a microvascular level, specially the assessment of non-reflow phenomenon after acute myocardial infarction.

Coronary Disease↗

PubMed2004

Effects of hypoxia on coronary flow reserve as determined by myocardial contrast echocardiography in swine.

BACKGROUND: Time-intensity curves derived from microbubble destruction/refilling sequences and recorded using myocardial contrast echocardiography (MCE) can provide parameters that correlate with coronary blood flow. The response of these parameters to adenosine vasodilatation correlates with coronary flow reserve (CFR) measured by fluorescent microsphere techniques (FMT). Currently, no data exist regarding the effect of physiological variables, such as hypoxia, on the determination of CFR by MCE. The purpose of this study was to define the effects of decreases in blood partial pressure of oxygen (PO2) on CFR as measured by MCE. METHODS: Studies were performed in 9 closed chest swine. Low-energy, real-time MCE was performed with commercial instruments in short axis view at papillary muscle level while infusing BR1 at 30 ml/h. High-energy ultrasound bursts (referred to as FLASH frames) destroyed the bubbles every 15 cardiac cycles, and resultant time-intensity curves derived from these sequences were fitted to the exponential function y = A [1-e(-bt)] + c, from which the rate of signal rise (b) was obtained. CFR was calculated as the ratio of b values after adenosine infusion to baseline and was obtained during the control period and after decreasing blood PO2 by giving nitrogen via a respirator to create artificial hypoxic conditions. CFR was independently determined by FMT. RESULTS: Nitrogen led to significant decreases in mean PO2, from (120.6 +/- 18.9) mmHg to (51.8 +/- 15.9) mmHg (P < 0.01). Adenosine produced a similar increase in CFR (2.5 fold vs 3.1 fold) as assessed by MCE and FMT during the control period. The decrease in PO2 post nitrogen resulted in a slight increase in values at rest: 0.46 +/- 0.15 to 0.53 +/- 0.18 for b and (1.39 +/- 0.66) ml x min(-1) x g(-1) to (1.72 +/- 0.30) ml x min(-1) x g(-1) for myocardial blood flow (MBF) (both P < 0.05). In addition, values decreased in response to adenosine using both techniques: 1.05 +/- 0.35 to 0.82 +/- 0.27 for b and (4.30 +/- 3.16) ml x min(-1) x g(-1) to (3.93 +/- 1.27) ml x min(-1) x g(-1) for MBF (both P < 0.05). Thus, CFR was markedly reduced under hypoxic conditions, to 1.4 by MCE (P < 0.05 compared with the baseline), and to 2.5 by FMT (P > 0.05 compared with the baseline). CONCLUSIONS: CFR values diminish under hypoxic conditions according to both MCE and FMT. The reductions in CFR involve both an increase in resting values and a decrease in post adenosine measurements, as determined by both techniques. The reduction in CFR under hypoxia is slightly greater using MCE than using FMT. Physiological variables, such as hypoxia, must be taken into consideration when assessing CFR by MCE.

Adenosine↗

PubMed1992

Contrast materials for cross-sectional imaging of the abdomen.

The development and clinical studies of contrast agents for cross-sectional abdominal imaging presently focus on the diagnosis of liver diseases and suitable oral contrast agents for MR imaging. The well-known paramagnetic agent, gadopentetate dimeglumine is now used for improving the differential diagnosis of liver lesions such as focal nodular hyperplasia in dynamic MR studies. Preclinical studies and initial clinical trials indicate that the new paramagnetic hepatobiliary contrast agent, manganese dipyridoxal diphosphate, might improve the sensitivity of MR imaging in the detection of liver lesions. With respect to dynamic contrast-enhanced CT in the detection of liver lesions, interest has focused on the question of the optimal scanning technique. Promising results have been obtained in initial studies of contrast agents for sonography, called microbubbles. This substance produces good visualization of the vascular status of liver tumors. Nuclear medicine somatostatin receptor imaging may be of special clinical interest because it allows even very small somatostatin-positive metastases to be detected and thus provides specific information for therapy planning in patients with positive scan results. Initial studies have shown that using contrast enhancement with MR imaging of the pancreas improves the contrast between pancreatic tissue and lesions. Manganese dipyridoxal diphosphate is taken up by pancreatic tissue, though the exact mechanism remains to be clarified, and may therefore have potential as a future MR contrast agent for evaluation of the pancreas. A number of oral MR contrast agents have now been tested in larger clinical trials. Both positive and negative oral agents are safe and well tolerated and achieve the aim of reliably delineating the gastrointestinal tract from other organs and pathologies in the abdomen.

Abdomen↗

PubMed2005

Characterization of focal liver lesions with a new ultrasound contrast agent using continuous low acoustic power imaging: comparison with contrast enhanced spiral CT.

PURPOSE: To evaluate the concordance of the enhancement patterns of a new ultrasound contrast agent (SonoVue) with those obtained with dual-phase contrast-enhanced spiral CT (CE-CT) in the characterization of focal liver lesions (FLLs). MATERIALS AND METHODS: Sixty-two patients with focal liver lesions discovered at ultrasound and also studied with CECT underwent contrast-enhanced ultrasound using continuous low acoustic power imaging after receiving a 2.4 ml bolus of the new US contrast agent SonoVue, consisting of a dispersion of sulphur hexafluoride microbubbles. The examinations were made using ATL HDI-5000, Acuson SEQUOIA and Aloka 5500 Prosound ultrasound systems with 5.2 MHz curved-array probes. The concordance between US and CE-CT images was evaluated on site by two radiologists blinded to CT RESULTS: The FLLs were assessed in the arterial (20 s after CM injection), portal (after 45-60 s) and late (after 120 s) phases for: 1) presence/absence of enhancement 2) distribution of enhancement (homogenous or target distribution, centripetal or centrifugal flow, and other), 3) qualitative enhancement pattern (hyperechoic, hypoechoic, or isoechoic) versus normal liver parenchyma. RESULTS: The concordance between SonoVue-enhanced US and CE-CT was 85%. Moreover during portal venous phase with CEUS it was possible to differentiate between malignancy or benignity of 91% of lesions. CONCLUSIONS: The preliminary data obtained in this study suggest that continuous low acoustic power imaging and contrast-enhanced US show similar results to CT in contrast distribution and contrast enhancement patterns.

Adult↗

PubMed2005

[Value of low dose dobutamine real-time myocardial contrast echocardiography in the assessment of coronary artery disease].

OBJECTIVE: To evaluate the value of quantitative real-time myocardial contrast echocardiography (RT-MCE) combined with low dose dobutamine stress test in the detection of coronary artery disease (CAD), and to assess the contribution of collateral blood flow (CBF) to myocardial perfusion. METHODS: Twenty-six hospitalized patients referred for coronary angiography and subsequent revascularization underwent routine echocardiography, RT-MCE at baseline and after low dose dobutamine administration. The images of RT-MCE were analyzed quantitatively from microbubble replenishment curves for myocardial perfusion and its reserve by using the QLab software. RESULTS: At baseline, both beta and A x beta (but not A) were decreased with the increase of severity of coronary stenosis (P < 0.01). Under dobutamine stress, A, beta and A x beta values were decreased with the increase of severity of coronary stenosis (P < 0.01), Graded decreasing in the reserves of A, beta and A x beta were observed with increasing coronary stenosis severity (P < 0.01). Furthermore, significant differences in beta, A x beta, and WMS were observed between segments with CBF and those without. CONCLUSION: Quantitative RT-MCE in conjunction with dobutamine stress can be used as a sensitive measure to identify and stratify CAD as well as to assess the contribution of collateral blood flow.

Adult↗

PubMed2005

[Absent right superior vena cava with left superior vena cava draining to an unroofed coronary sinus].

We describe the case of a 1-month-old infant with a complete atrioventricular septal defect with right dominance, situs solitus, and drainage from the persistent left superior vena cava to the coronary sinus. Corrective surgery was carried out without previous cardiac catheterization. During the operation, the right superior vena cava was found to be absent. Cyanosis and head-and-neck edema were observed in the immediate postoperative period. Transthoracic echocardiography carried out after injection of a small volume of stirred saline into an epicranial vein demonstrated the presence of microbubbles in the left cardiac cavities. A second operation was performed to prevent drainage from the left superior vena cava to the left atrium (via the unroofed coronary sinus) and to insert a PTFE conduit between the innominate vein and the right atrial appendage. The outcome was excellent. In this report, the embryological, clinical, diagnostic and therapeutic characteristics of this entity are discussed.

Blood Vessel Prosthesis Implantation↗

PubMed2000

Drug Delivery Systems--Fifth US-Japan Symposium. 12-17 December 1999, Lahaina, Hawaii.

The field of drug delivery is moving rapidly from the more efficacious delivery of 'old' drugs, to the delivery of therapeutic peptides, proteins, oligonucleotides and genes. Liposomes, polymers, microbubbles, nanoparticles, wafers and chips are the jargon, and entrepreneurialism is the prevailing force. Indeed, the scientific spirit is overwhelmed by the push to market, as fledgling companies compete or collaborate with the established pharma industry in converting concepts into profits. The 'Holy Grail' is a slice of the multi-billion dollar global market for these specialized, high-tech products.

Journal Article↗

PubMed2005

Contrast enhanced harmonic ultrasound for differentiating breast tumors - first results.

PURPOSE: To investigate the extent to which indeterminate lesions of the breast can be differentiated in the early and late phase after bolus injection of the ultrasound contrast medium Optison. MATERIALS AND METHODS: Fifty female patients (mean age: 49 years) with a altogether 53 preoperatively impalpable indeterminate breast tumors, 20 fibroadenomas and 33 carcinomas, were examined by B-mode imaging and contrast medium-enhanced ultrasound with power Doppler (three patients had multifocal carcinomas). The tumors had a diameter of 5-15 mm (mean diameter: 9 mm). Histological confirmation was performed in all lesions by vacuum biopsies and/or surgical preparation. All examinations were performed with a multifrequency linear array probe (5-10 MHz, Logiq9 and Logiq 7, GE). Power Doppler (PD) and B-mode imaging as well as tissue harmonic imaging (THI) were employed. A bolus of 0.5 ml Optison was injected intravenously and spreading of the contrast enhancement and washout in the tumors were followed for at least 20 minutes. A low mechanical index was chosen to avoid early destruction of the microbubbles. Maximum tumor size was measured and tumors vessels were evaluated in digital cine ultrasound sequences. RESULTS: Without CM administration, 14 of 19 tumor lesions smaller than 10 mm could be distinguished better from the surrounding tissue with THI compared to fundamental B-mode imaging. Both benign (17/20) and malignant (30/33) tumors exhibited increased tumor marginal vessels or intratumoral vessels in the early phase after CM injection. A diffuse contrast medium accumulation was observed in the late phase (8-18 min, mean: 12 min) in 30 of 33 malignant tumors, but in none of the benign tumors. The diagnostic confirmation for this late enhancement was there with 90% for the malignant tumors. CONCLUSION: After intravenous bolus administration of Optison, breast carcinomas appear to have a prolonged diffuse enhancement of central tumor vasularity in the late phase compared to an earlier marginal vascularity of fibroadenomas.

Adult↗

PubMed2005

[Characterization of focal liver lesions using an innovative contrast-enhanced ultrasound technique].

OBJECTIVE: To evaluate the clinical performance of an innovative contrast-enhanced ultrasound (CEUS) technique in characterization of focal liver lesions (FLL). METHODS: CEUS was performed in 505 patients with FLLs. A sulfur hexafluoride-filled microbubble ultrasound contrast agent and a continuous real-time imaging technique of contrast pulse sequencing were used. The observation items included initial nodule enhancement time, enhancement level and pattern, and dynamic evolution of enhancement along with the CEUS phases. RESULTS: There were similar findings for both malignant and benign FLLs in initial enhancement time and enhancement level on CEUS. The dynamic evolution of enhancement along with enhancement phase was the most significant parameter for characterization of FLLs. Most malignant lesions showed enhancement at arterial phase and hypo-enhancing at late phase, whereas the benign lesions presented enhancement at arterial phase and persistent hyper- or iso-enhancing until late phase. Using these characteristics as a diagnostic criteria, the sensitivity, specificity, positive predicative value, negative predicative value and accuracy of CEUS in identifying malignant FLLs were 95.7% (313/327), 86.0% (153/178), 92.6% (313/338), 91.6% (153/167) and 92.3% (466/505), respectively. CONCLUSIONS: Characterization of FLLs by using the innovative CEUS technique is recommendable due to its safety, facility and high accuracy.

Adult↗

PubMed2005

Usefulness of dobutamine stress myocardial contrast echocardiography for assessing coronary artery disease.

BACKGROUND: Quantitatively assessing myocardial perfusion and its reserve is of great importance for the diagnosis and stratification of patients with coronary artery disease (CAD), and represents an important goal of myocardial contrast echocardiography. In this study we sought to test the usefulness of low dose dobutamine stress real-time myocardial contrast echocardiography (RT-MCE) in the assessment of CAD, and to explore the relationship between perfusion reserve and contractile reserve. METHODS: Twenty-six patients with suspected or clinical diagnosed CAD were enrolled and underwent RT-MCE at baseline and under low dose dobutamine stress, and subsequent coronary angiography. RT-MCE images were analyzed quantitatively from microbubble replenishment curves for myocardial perfusion and its reserve. RESULTS: At baseline, significant differences in beta (0.28 +/- 0.12, 0.25 +/- 0.09, 0.22 +/- 0.06, 0.20 +/- 0.07 respectively, P < 0.01) and A x beta (1.37 +/- 0.46, 1.28 +/- 0.47, 1.13 +/- 0.37, 0.91 +/- 0.32, respectively, P < 0.01) were observed among four segment groups with graded coronary artery stenosis severity (normal; 30% - 69% stenosis; 70% - 90% stenosis; and beyond 90% stenosis), but not observed in parameter A. When under stress, significant differences in A (5.73 +/- 1.28, 5.63 +/- 1.01, 4.96 +/- 0.81, 4.57 +/- 0.62, respectively, P < 0.01), beta (0.67 +/- 0.17, 0.55 +/- 0.19, 0.32 +/- 0.13, 0.25 +/- 0.08, respectively, P < 0.01) and A x beta (3.81 +/- 1.20, 3.11 +/- 1.17, 1.59 +/- 0.82, 1.12 +/- 0.37, respectively, P < 0.01) were observed among the formerly mentioned groups. Graded decreases in A reserve (1.20 +/- 0.53, 1.11 +/- 0.16, 0.98 +/- 0.12, 0.99 +/- 0.13, respectively, P < 0.01), beta reserve (2.65 +/- 1.07, 2.32 +/- 0.82, 1.44 +/- 0.40, 1.29 +/- 0.34, respectively, P < 0.01) and A x beta reserve (3.05 +/- 1.63, 2.59 +/- 1.01, 1.42 +/- 0.44, 1.27 +/- 0.34, respectively, P < 0.01) could also be observed with increasing coronary stenosis severity. In five segments groups scored by WMS (1 - 5), concordance between contractile function and myocardial perfusion could be found both at rest (beta: 0.28 +/- 0.11, 0.22 +/- 0.08, 0.21 +/- 0.05, 0.17 +/- 0.05, 0.19 +/- 0.06, respectively, P < 0.01; A x beta: 1.29 +/- 0.48, 0.98 +/- 0.45, 0.94 +/- 0.29, 0.76 +/- 0.30, 0.92 +/- 0.32, respectively, P < 0.01) and under stress (beta: 0.59 +/- 0.20, 0.35 +/- 0.15, 0.27 +/- 0.08, 0.17 +/- 0.05, 0.20 +/- 0.05, respectively, P < 0.01; A x beta: 3.07 +/- 1.38, 1.62 +/- 0.82, 1.28 +/- 0.40, 0.78 +/- 0.24, 0.93 +/- 0.22, respectively, P < 0.01). This concordance is also valid in terms of the reserves, and the MCE parameters in segments with ameliorated contractile function are significantly higher than in those without. CONCLUSIONS: Quantitative RT-MCE in conjunction with dobutamine stress shows promise in identifying and stratifying CAD and in exploring the perfusion-contractile correlation.

Adult↗

PubMed2005

[Myocardial perfusion and contrast echocardiography. Application to acute coronary syndrome].

After mastering epicardial revascularisation, the therapeutic management of acute coronary syndrome has progressively turned towards the preservation of the capillary microcirculation. In this respect, contrast echocardiography provides all the answers to the main questions which arise, and is available within a timeframe and place compatible with the management of such patients. The techniques for microbubble detection, quantification tools, and contrast agents are well optimised for routine use both for initial diagnosis as well as monitoring the therapeutic effectiveness. It is only the administrative authorisation which is currently lacking treatment.

Angina, Unstable↗

PubMed2005

High mechanical index post-contrast ultrasonography improves tissue structural display of hepatocellular carcinoma.

BACKGROUND: The advent of second generation agent-SonoVue and low mechanical index real-time contrast enhanced ultrasonography (CEUS) imaging have been shown to improve the diagnostic performance of ultrasonography in hepatocellular carcinoma (HCC). But no report has described the effect of high mechanical index (MI) post-CEUS. This study aimed to investigate the value of post-CEUS in displaying tissue structures of HCC. METHODS: Seventy-six HCCs in 65 patients were included in the study. Each patient underwent three scans, high-MI (MI: 0.15-1.6) pre-contrast ultrasound, low-MI (MI: 0.04-0.08) CEUS with contrast agent SonoVue, and high-MI post-contrast ultrasound, which was performed within 3 minutes after CEUS. The size, boundary, echogenicity, internal echotexture and posterior acoustic enhancement of the HCCs in the conventional scans before and after CEUS were evaluated. According to pathological evidence, diagnosis rates of pre-contrast, CEUS and post-contrast scans were determined and compared. The potential mechanism of post-contrast ultrasound imaging was also discussed. RESULTS: Compared with pre-contrast, post-contrast ultrasound showed improvement in image quality in most HCCs: twenty-six (34.2%) more lesions showed well defined margins and fourteen (18.4%) more nodules showed halo sign; twenty-three (30.3%) lesions demonstrated enlarged in sizes; changes in echogenicity were seen in 30 lesions (39.5%); eighteen (23.7%) more lesions showed heterogenecity and 20 (26.3%) more lesions showed "mosaic" or "nodule-in-nodule" sign; twelve (15.8%) more lesions showed posterior acoustic enhancement. Post-contrast ultrasound showed increased diagnostic accuracy of 93.4% (71/76), compare with 88.2% (67/76) of CEUS alone. CONCLUSIONS: High-MI post-contrast ultrasound utilizes harmonic signals during the rupture of microbubbles, and significantly improves the display of echo-characteristics of HCCs in ultrasound images, which adds diagnostic values for CEUS. Post-contrast ultrasound could play an important role in tissue characterization, and may be included in CEUS protocols.

Adult↗

PubMed1991

[Tumor hemodynamics in hepatic nodules associated with liver cirrhosis: relationship between cancer progression and tumor hemodynamic change].

Tumor hemodynamics including arterial vascularity (AV) and portal perfusion (PP) were evaluated in histologically confirmed 55 hepatic nodules associated with cirrhosis using ultrasonographic (US) angiography during intraarterial carbon dioxide microbubbles injection and CT during arterial portography. Tumor hemodynamic patterns were classified into 6 types as follows: Type I (n = 10): PP (+), AV (hypo); Type I' (n = 2): PP (+), AV (iso); Type II (n = 5): PP (-), AV (hypo); Type III (n = 8): PP (-), AV (iso); Type IV (n = 25): PP (-), AV (hyper), Type V (n = 5): PP (partially +), AV (vascular spot in hypovascular). Eight nodules of Type I were diagnosed as benign nodules histologically including adenomatous hyperplasia (AH) (n = 6) and regenerative nodule (n = 2). Hundred percent (5/5) of Type II and 88% (7/8) of Type III nodules were well-differentiated HCC, in contrast to 8% (2/25) of Type IV nodules, typical HCCs. Fatty metamorphosis was observed in 75% (6/8) of Type III nodules, in contrast to 16% (4/25) of typical (classical) HCC nodules (Type IV). We concluded that at the malignant transformation from AH to HCC, reduction of portal blood flow in the nodule precedes the initiation of the increase of the arterial tumor vessel. Moreover, early stage HCC could exhibit hypovascular (Type I, II), isovascular (Type III), or vascular spot in hypovascular pattern (Type V) compared with a typical HCC (Type IV). It was also suggested that the more mature as a neoplasms the HCC becomes, the more the arterial tumor vessel in the nodule increases and fatty metamorphosis of well-differentiated HCC is highly related with tumor hemodynamic condition, i.e., hypoperfusion state from both arterial and portal vessel.

Carcinoma, Hepatocellular↗

PubMedDate not supplied

Four-dimensional ultrasonography for therapeutic radiofrequency ablation for hepatocellular carcinoma.

BACKGROUND/AIMS: We examined whether four-dimensional real-time flow imaging on ultrasonography (US) is valuable to display the accurate position of percutaneous radiofrequency ablation (RFA) needle in the nodule of hepatocellular carcinoma (HCC). METHODOLOGY: Ten patients with 12 HCC nodules were studied; nine were infected with hepatitis C virus (HCV) and one was diagnosed as non-B non-C. Diagnosis was done by helical dynamic CT and/or celiac angiography. Tumor vascularities in the early arterial and post-vascular phases after injection of a microbubble contrast agent were assessed by real-time US scanning of coded harmonic imaging and intermittent interval-delay scanning with a wide-band power Doppler technology. Percutaneous RFA was performed with four-dimensional real-time flow imaging under US to display the accurate position of cool-tip needle. RESULTS: It was possible to obtain accurate position of the needle during RFA procedure in all 12 nodules. The needle was confirmed to be inserted into the center of the tumor nodule by various angles. The simultaneous study before RFA therapy showed the inflow of arterial blood and tumor staining in all nodules at early arterial phase of coded harmonic angio on contrast-enhanced US scan. Posttreatment study to evaluate the therapeutic efficacy showed no blood flow at both early vascular and post-vascular phases. No residual blood flow was noted on early phase of CT scan with adequate safety margin. There was no discrepancy in the finding at early phase between contrast-enhanced US and dynamic CT. CONCLUSIONS: It appeared that four-dimensional real-time US provided more perceptible information on the spatial relationship between RFA needle and the target lesion, and resulted in accurate therapeutic efficacy for percutaneous RFA procedure.

Adult↗

PubMed2006

Contrast-enhanced ultrasound imaging of prostate cancer.

Ultrasound imaging of the prostate is commonly used to assess the size of the gland and for needle placement during systematic biopsy. Ultrasound evaluation of prostate cancer is limited by difficulty in distinguishing benign from malignant tissue. Although Doppler techniques may provide some improvement in the detection of prostate cancer, targeted biopsy based on conventional ultrasound with Doppler is not sufficient to replace systematic biopsy. Contrast-enhanced ultrasound imaging techniques that employ microbubble contrast agents represent an innovative approach to imaging of the neovascularity associated with prostate cancer. This review describes the application of contrast-enhanced ultrasound to improve detection and assessment of prostate cancer.

Journal Article↗