颈部动脉扭曲的彩色多普勒超声诊断

目的 探讨彩色多普勒超声在颈部动脉扭曲中的应用.方法 回顾性分析28例颈部动脉扭曲的超声表现.结果 颈动脉扭曲可发生于一侧,也可为两侧.颈动脉扭曲患者多合并动脉粥样硬化.二维图像可显示多种形态的弯曲.彩色多普勒血流显示,在扭曲的血管内以弯曲处为分界,分别充盈红、蓝两种血流信号.严重扭曲者在弯曲处可见少量杂色血流信号.脉冲多普勒频谱分析,弯曲处血液流速较平直处增快,阻力指数增高.结论 彩色多普勒超声可实时、无创地对血管进行多次、反复的定期观察.     

糖尿病足动脉血管早期病变行彩色多普勒超声诊断对定位准确、无创性的价值研究

目的分析探讨给予糖尿病足动脉血管早期病变患者彩色多普勒超声诊断取得的临床应用价值,分析探究其定位准确以及无创价值。方法选取2018年1月—2020年8月该院收治的糖尿病足动脉血管早期病变患者作为研究对象,确诊患者共计112例,在诊断过程中均采取彩色多普勒超声诊断、超声造影检查,同时将X线数字减影血管造影的诊断结果作为金标准,评估分析应用彩色多普勒超声诊断、超声造影检查取得的诊断效果。结果彩色多普勒超声诊断的确诊率为98.21%,误诊率为1.79%,和超声造影检查结果、金标准进行比较,差异无统计学意义(χ²=4.073,P>0.05);对比分析采取3种诊断措施以后患者血管病变状况,差异无统计学意义(Z=0.500,P>0.05)。对比分析超声造影以及彩色多普勒超声应用后脉搏波传导速度以及踝肱指数、脉压指数,差异有统计学意义(t=12.027、11.685、25.017,P<0.05)。结论给予糖尿病足动脉血管早期病变患者彩色多普勒超声诊断措施对于准确分析血管病变情况具有积极意义,具有较高的定位准确以及无创价值。     

Revascularization in the rabbit hindlimb: dissociation between capillary sprouting and arteriogenesis

OBJECTIVE: Animal models of hindlimb ischemia are critical to our understanding of peripheral vascular disease and allow us to evaluate therapeutic strategies aimed to improve peripheral collateral circulation. To further elucidate the processes involved in revascularization following ischemia, we evaluated the temporal association between tissue ischemia, vascular endothelial cell growth factor (VEGF) release, angiogenesis (capillary sprouting), arteriogenesis (growth of the larger muscular arteries), and reserve blood flow (functional collateral flow). METHODS: New Zealand White rabbits (male 3-4 kg) were evaluated at specific days (0, 5, 10, 20 or 40) following femoral artery removal for measurement of hindlimb blood flow, skeletal muscle lactate production and VEGF content, capillary density (a marker of angiogenesis), and angiographic score (a marker of arteriogenesis). RESULTS: Maximal capillary sprouting occurred within 5 days of femoral artery removal and was temporally associated with reduced resting hindlimb blood flow, increased lactate release and detectable levels of skeletal muscle VEGF. The growth of larger angiographically visible collateral vessels occurred after 10 days and was not temporally associated with ischemia or skeletal muscle VEGF content, but did coincide with a large functional improvement in the reserve blood flow capacity of the limb. CONCLUSIONS: Following femoral artery removal in the rabbit, the time course of angiogenesis and arteriogenesis were clearly distinct. Tissue ischemia and/or VEGF may stimulate capillary sprouting, but this response does not translate to a significant improvement in collateral flow. The growth and development of the larger collateral vessels was correlated with a large functional improvement in collateral flow, and occurred at a time when VEGF levels were undetectable.     

Doppler color flow image size: dependence on instrument settings

Doppler color flow imaging provides important qualitative information about the location and spatial distribution of intracardiac blood flow. However, the effect of instrument-related variables on the size of color Doppler images requires further definition. Flow of a silicone particle solution was established in a tube or cylinder and scanned as color gain, pulse repetition frequency, depth, and transducer frequency were varied. The diameter of Doppler color flow images were measured during constant laminar or disturbed flow parallel to the ultrasound beam and during laminar flow perpendicular to the ultrasound beam. The diameter of color Doppler images of laminar flow perpendicular and parallel to the beam varied directly with color gain. Diameter varied inversely with transducer frequency for laminar flow parallel to the transducer and inversely with pulse repetition frequency for laminar flow perpendicular to the transducer. The diameter of laminar flow parallel to the transducer varied directly with the depth of the flow area below the transducer. The size of the color flow dropout of laminar flow exactly perpendicular to the ultrasound beam varied directly with transducer frequency and inversely with gain. During disturbed flow parallel to the transducer, the diameter of the image varied directly with gain and inversely with transducer frequency and pulse repetition frequency. Instrument settings have a significant impact on the size of color Doppler images. Understanding the effects of changes in these variables is important for reliable diagnostic use of Doppler color flow imaging.     

Vascular endothelial growth factor stimulates angiogenesis without improving collateral blood flow following hindlimb ischemia in rabbits

This study was designed to test the ability of adenovirus-delivered vascular endothelial growth factor (Ad-VEGF) to stimulate angiogenesis and arteriogenesis in the rabbit hindlimb following the induction of ischemia and to evaluate the functional changes in the collateral circulation. Ten days after the surgical induction of hindlimb ischemia, either a control virus (1 × 10⁹pfu) or an adenovirus containing the gene for VEGF₁₆₅ (1 × 10⁶, 1 × 10⁷, 1 × 10⁸, or 1 × 10⁹pfu) was administered intramuscularly into the ischemic limb. Thirty days after administration of the adenoviral vectors, skeletal muscle capillary density was assessed and angiography was performed as markers of angiogenesis and arteriogenesis, respectively. Hindlimb blood flow was directly measured and hyperemic tests were performed to evaluate the functional improvements in collateral blood flow. Animals treated with Ad-VEGF at 1 × 10⁸ and 1 × 10⁹pfu showed elevated levels of circulating VEGF and dose-dependent hindlimb edema. These doses also led to a robust angiogenic response (i.e., increase in capillary density), but failed to improve collateral blood flow. Consistent with the lack of a functional response, there was no angiographic evidence of enhanced arteriogenesis with any dose of Ad-VEGF. Following the induction of hindlimb ischemia, administration of Ad-VEGF stimulated capillary sprouting (i.e., angiogenesis), but did not increase the growth and development of larger conduit vessels (i.e., arteriogenesis) or improve collateral blood flow. These results support the concept that VEGF may not be expected to have therapeutic utility for the treatment of peripheral or myocardial ischemia.     

Longitudinal power Doppler ultrasonographic assessment of joint inflammatory activity in early rheumatoid arthritis: predictive value in disease activity and radiologic progression

OBJECTIVE: To evaluate the sensitivity to change of power Doppler ultrasound (PDUS) assessment of joint inflammation and the predictive value of PDUS parameters in disease activity and radiologic outcome in patients with early rheumatoid arthritis (RA). METHODS: Forty-two patients with early RA who started therapy with disease-modifying antirheumatic drugs underwent blinded sequential clinical, laboratory, and ultrasound assessment at baseline, 3 months, 6 months, and 1 year and radiographic assessment at baseline and 1 year. For each patient, 28-joint Disease Activity Score (DAS28) was recorded at each visit. The presence of synovitis was investigated in 28 joints using gray-scale ultrasonography and intraarticular power Doppler signal. Active synovitis was defined as intraarticular synovitis detected with power Doppler signal. The ultrasound joint count for active synovitis and an overall joint index for power Doppler signal were calculated. Sensitivity to change of PDUS variables was assessed by estimating the smallest detectable difference (SDD) from the intraobserver variability. RESULTS: The SDD for ultrasound joint count for active synovitis and ultrasound joint index for power Doppler signal was lower than mean changes from baseline to 3 months, 6 months, and 1 year. Time-integrated values of PDUS parameters demonstrated a highly significant correlation with DAS28 after 1 year (r = 0.63, P < 0.001) and a stronger correlation with radiographic progression (r = 0.59-0.66, P < 0.001) than clinical and laboratory parameters (r < 0.5). CONCLUSION: PDUS is a sensitive and reliable method for longitudinal assessment of inflammatory activity in early RA. PDUS findings may have a predictive value in disease activity and radiographic outcome.     

Statins augment collateral growth in response to ischemia but they do not promote cancer and atherosclerosis

3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors, or statins, are widely prescribed to lower cholesterol. Recent reports suggest that statins may promote angiogenesis in ischemic tissues. It remains to be elucidated whether statins potentially enhance unfavorable angiogenesis associated with tumor and atherosclerosis. Here, we induced hind limb ischemia in wild-type mice by resecting the right femoral artery and subsequently inoculated cancer cells in the same animal. Cerivastatin enhanced blood flow recovery in the ischemic hind limb as determined by laser Doppler imaging, whereas tumor growth was significantly retarded. Cerivastatin did not affect capillary density in tumors. Cerivastatin, pitavastatin, and fluvastatin inhibited atherosclerotic lesion progression in apolipoprotein E-deficient mice, whereas they augmented blood flow recovery and capillary formation in ischemic hind limb. Low-dose statins were more effective than high-dose statins in both augmentation of collateral flow recovery and inhibition of atherosclerosis. These results suggest that statins may not promote the development of cancer and atherosclerosis at the doses that augment collateral flow growth in ischemic tissues.     

Usefulness of three-dimensional color Doppler sonography for the differential diagnosis of subpleural lesions]

The purpose of our investigation was to assess the usefulness of three-dimensional color Doppler sonography (velocity mode and power mode) for the differential diagnosis of subpleural lesions. Thirty lesions (11 pneumonias, 5 lung abscesses, 11 primary lung cancers, 3 metastatic lung cancers) were examined. Three-dimensional images were reconstructed by a maximum intensity projection method. Three-dimensional representations of intralesional blood flow became available for all lesions approximately 11 seconds after scanning. In every case, the entire vasculature of the tumor, the pneumonia, the abscess, or the inflamed region of the lung was appreciated more easily from three-dimensional images than from two-dimensional images. We classified the color flow pattern of subpleural lesions depicted by color flow imaging into seven groups. Color flow was depicted better by the three-dimensional color Doppler power mode than the velocity mode. Three-dimensional color flow patterns observed in power mode, patterns of the pneumonias and the lung cancers differed significantly. Our results suggest that the three-dimensional color Doppler power mode is useful for the differential diagnosis of subpleural lesions.     

过量服用蛋氨酸所致高同型半胱氨酸血症对缺血性血管新生的抑制作用

高同型半胱氨酸血症是引起动脉粥样硬化的一种独立危险因素。过量服用蛋氨酸会导致血清中同型半胱氨酸浓度增高、内皮功能受损、血管舒缩功能减弱。本研究使用过量服用蛋氨酸导致高同型半胱氨酸血症大鼠，与对照组比较，观察缺血下肢血管新生的情况，判断高同型半胱氨酸血症对缺血性血管新生的影响。将36只雄性Sprague-Dawley大鼠分为两组：对照组和高同型半胱氨酸血症组。对照组始终给予自来水；高同型半胱氨酸血症组则给予含有0．5％蛋氨酸的饮水。两组动物分别按上述方法给予不同饮水2周后，手术切除左侧股动、静脉，观察缺血28d内缺血区域血管新生和侧枝血管形成的情况。过量服用蛋氨酸导致的高同型半胱氨酸血症减弱了大鼠下肢慢性缺血性血管新生和侧枝血管的建立，这可能与高同型半胱氨酸血症减弱内皮源性一氧化氮生物活性有关。     

Contrast-enhanced power Doppler ultrasound in the diagnosis and follow-up of inflammatory abdominal masses in Crohn's disease

OBJECTIVE: The purpose of this study was to evaluate the potential usefulness of contrast-enhanced power Doppler ultrasound in the detection and follow-up of local complications (phlegmon and abscess) in Crohn's disease. METHODS: With this aim, 28 patients with suspected abdominal inflammatory mass were examined with power Doppler ultrasound before and after intravenous administration of the ultrasound contrast agent Levovist, with evaluation of vascularity within and/or around the inflammatory mass. Colour Doppler flow was characterized as clearly visible, minimally visible or absent. All the patients underwent a post-contrast computed tomography exam. RESULTS: Power Doppler ultrasound, after administration of contrast medium, allows the detection of small inflammatory masses in Crohn's disease, particularly those under 2 cm in diameter, when compared with computed tomography. CONCLUSIONS: We conclude that contrast-enhanced power Doppler ultrasound is a sensitive method for the detection of small abdominal inflammatory masses and for differential diagnosis between phlegmon and abscess.     

彩色多普勒超声在腹主动脉瘤破裂诊断中的应用价值

目的探讨彩色多普勒超声在腹主动脉瘤破裂诊治中的价值。方法回顾性分析14例腹主动脉瘤破裂患者的灰阶和彩色多普勒超声图像,从腹主动脉瘤发生部位、瘤体大小、瘤壁厚度、瘤体破裂部位、瘤体破裂时血管内异常回声、血管周边形成血肿、出现腹腔游离液及瘤体内彩色多普勒表现等方面进行分析,并与手术结果、CT血管成像或磁共振检查结果进行对比。结果腹主动脉瘤超声检出率100%,肾上型2例,肾下型12例,瘤体最大直径6.1～1 3.2 cm,超声诊断腹主动脉瘤壁破裂处显示率14.3%,腹主动脉瘤旁腹腔血肿显示率66.7%,腹腔积液显示率80.0%,腹膜后血肿显示率12.5%。结论超声作为可移动简便无损伤的检查方法 ,可以快速的对腹主动脉瘤破裂和其他腹腔器官肿物引起的急腹症进行鉴别,在腹主动脉瘤的发现、随访监测、腹主动脉瘤破裂急诊入院有较高的临床应用价值。     

Hyperhomocysteinemia impairs angiogenesis in response to hindlimb ischemia

Hyperhomocysteinemia (HH) is an independent risk factor for atherosclerosis, including peripheral arterial occlusive disease (PAOD). Because angiogenesis and collateral vessel formation are important self-salvage mechanisms for ischemic PAOD, we examined whether HH modulates angiogenesis in vivo in a rat model of hindlimb ischemia. Rats were divided into 3 groups: the control group was given tap water, the HH group was given water containing L-methionine (1 g x kg(-1) x d(-1)), and the HH+L-arg group was given water containing methionine (1 g x kg(-1) x d(-1)) and l-arginine (2.25 vol%). At day 14 of the dietary modifications, the left femoral artery and vein were excised, and the extent of angiogenesis and collateral vessels in the ischemic limb were examined for 4 weeks. Plasma homocysteine levels significantly increased (P:<0.001), and plasma and tissue contents of nitrite+nitrate as well as tissue cGMP levels significantly decreased in the HH group compared with the control group (P:<0.01). Laser Doppler blood flowmetry (LDBF) revealed a significant decrease in the ischemic/normal limb LDBF ratio in the HH group at days 7, 14, 21, and 28 (P:<0.01 versus control). Angiography revealed a significant decrease in the angiographic score in the HH group at day 14 (P:<0.001 versus control). Immunohistochemistry of ischemic tissue sections showed a significant reduction in the capillary density in the HH group (P:<0. 001 versus control). Oral l-arginine supplementation in rats with HH (HH+L-arg) restored the decreased plasma and tissue nitrite+nitrate and cGMP contents (P:<0.05) as well as angiogenesis, as assessed by LDBF (P:<0.05 versus HH), angiographic score (P:<0.01 versus HH), and capillary density (P:<0.001 versus HH). In summary, HH impaired ischemia-induced angiogenesis and collateral vessel formation in a rat model of hindlimb ischemia in vivo. The mechanism of the HH-induced impairment of angiogenesis might be mediated in part by a reduced bioactivity of endogenous NO in the HH state.     

A new flow model for Doppler ultrasound study of prosthetic heart valves

BACKGROUND AND AIM OF THE STUDY: Steady and pulsatile flow models used to assess the hydrodynamic aspects of prosthetic heart valves are generally made of Plexiglas and Lucite tubing. They often allow continuous-wave and pulsed-wave Doppler ultrasound velocity measurements to be made parallel to the flow, but cannot be used as such for ultrasound scanning of valve inflow and outflow velocities because of ultrasonic reverberation and refraction by the tubing. The aim of the study was to develop a new flow model which allowed ultrasonic scanning of the prosthetic valve flow for three-dimensional (3D) reconstruction of color Doppler flow distributions. METHODS: The flow model, designed with left ventricular and aortic chambers composed of agar gel which mimics the ultrasound characteristics of biological tissues, was developed and tested for comparative in vitro hydrodynamic and Doppler ultrasonic studies of aortic prosthetic valves. An electromagnetic flowmeter and a pressure monitor provided the flow and pressure signals for the hydrodynamic tests. The Doppler ultrasonic evaluation was performed with an Ultramark 9 HDI ultrasound system and a 3D ultrasound imaging system. The model was designed to enable assessment of prosthetic valve performance by pulsed-wave and continuous-wave Doppler velocity measurements, as well as by 3D color Doppler velocity measurements obtained by ultrasonic scanning of the left ventricle or aortic chamber with an ultrasound probe mounted on a motorized translation assembly. RESULTS: The study results showed that this new flow model can provide 3D color Doppler velocity distributions as well as accurate comparisons of hydrodynamic parameters of mechanical and bioprosthetic heart valves derived from Doppler and catheter measurements, both under steady and pulsatile flow conditions. CONCLUSION: This new flow model can be used to evaluate the usefulness of hydrodynamic parameters for the assessment of prosthetic heart valves using both conventional Doppler echocardiography, as currently used in patients, and 3D color Doppler ultrasonic imaging.     

Color Doppler transabdominal ultrasonography for the assessment of the patients with inflammatory bowel disease during treatment

Color and power Doppler ultrasound are useful methods for the assessment of patients with gastrointestinal diseases. The aim of our study was to assess color Doppler and power Doppler ultrasound, during the evolution of patients with ulcerative colitis and Crohn's disease treated with salazopyrin. We included in the study 10 patients with inflammatory bowel diseases diagnosed by colonoscopy with multiple biopsies. All the patients underwent color and power Doppler ultrasound using Jeffrey criteria for the evaluation of intestinal vasculature. Biological examinations included: erythrocyte sedimentation rate, serum C reactive protein, blood cell count, fibrinogenemia, protein electrophoresis and immunoelectrophoresis. The results of our study indicated a diminished blood flow at the level of the affected intestinal segments after one month of salazopyrin treatment. Color and power Doppler ultrasound might thus represent a useful method for monitoring the response in inflammatory bowel disease treatment.     

A new approach to studying angiogenesis in rheumatoid arthritis by means of power Doppler ultrasonography and measurement of serum vascular endothelial growth factor

OBJECTIVE: To evaluate angiogenesis as an essential component of pannus formation and cartilage destruction in rheumatoid arthritis (RA) using power Doppler ultrasonography (PDUS) and serum vascular endothelial growth factor (VEGF) measurement. METHODS: Twenty-one RA patients with a painful and swollen wrist and 12 healthy controls were examined with ultrasound. By means of standard scans, vascularity near and inside the joint capsule was visualized with PDUS. Two trained investigators performed sonography. Representative video clips were stored and read by two independent investigators, under blinded conditions, with regard to the microvascular Doppler flow being either inside or outside the joint capsule and with respect to a qualitative estimate of the intensity of blood flow, according to a grading from 1 to 3. Serum levels of VEGF were measured with a standard quantitative sandwich ELISA. RESULTS: The power Doppler mode identified increased synovial microvascular blood flow inside the joint capsule in 17 of 21 RA patients (81%) vs one of the healthy controls. We found large variation in serum VEGF levels in RA patients and in healthy controls. The degree of synovial vascularity determined by PDUS showed no correlation with the immediate serum VEGF level in the same patient. CONCLUSION: The high correlation between intra-articular microvascular power Doppler flow and clinical synovitis in RA patients (P<0.0001) indicates that PDUS may be helpful in studying the role of synovial blood vessels in rheumatoid inflammation.     

CONTRAST‐ENHANCED ENDOSCOPIC ULTRASONOGRAPHY IN THE DIAGNOSIS OF PANCREATO‐BILIARY DISEASES

In diagnostic imaging, techniques represented by computed tomography (CT) and magnetic resonance imaging (MRI), diagnosis by evaluation of plain images in combination with contrast‐enhanced images is considered important. Recently, the ultrasound contrast media that can be administered from peripheral veins have been developed, and their utility is reported not only for the circulatory organ area but also the digestive organ area, mainly for liver diseases. As for the pancreato‐biliary diseases, there often are the cases that visualization of the diseases itself is not easy by transabdominal ultrasonography, so, the evaluation of contrast‐enhanced ultrasonography remains difficult. In contrast, endoscopic ultrasonography (EUS) is thought to be one of the most valuable modality for those diseases. The mainstream of an operation method of EUS was mechanical radial type, but in late years, endoscopic ultrasonography of an electronic linear method and an electronic radial method have been developed. Because an electronic scan method was adopted, we get possible to apply technology of color Doppler flow imaging and power Doppler flow imaging and harmonic imaging methods to EUS. We would like to outline the usefulness of contrast‐enhanced color/power Doppler EUS and contrast‐enhanced harmonic EUS, moreover, tissue harmonic imaging and three dimensional imaging, on the basis of our experiences.     

CEUS： A new imaging approach for postoperative vascular complications after right-lobe LDLT

AIM： To investigate contrast-enhanced ultrasound （CEUS） for early diagnosis of postoperative vascular complications after right-lobe living donor liver transplantation （RLDLT）. METHODS： The ultrasonography results of 172 patients who underwent RLDLT in West China Hospital, Sichuan University from January 2005 to June 2008 were analyzed retrospectively. Among these 172 patients, 16 patients＇ hepatic artery flow and two patients＇ portal vein flow was not observed by Doppler ultrasound, and 10 patients＇ bridging vein flow was not shown by Doppler ultrasound and there was a regional inhomogeneous echo in the liver parenchyma upon 2D ultrasound. Thus, CEUS examination was performed in these 28 patients. RESULTS： Among the 16 patients without hepatic artery flow at Doppler ultrasound, CEUS showed nine cases of slender hepatic artery, six of hepatic arterial thrombosis that was confirmed by digital subtraction angiography and/or surgery, and one of hepatic arterial occlusion with formation of lateral branches. Among the two patients without portal vein flow at Doppler ultrasound, CEUS showed one case of hematoma compression and one of portal vein thrombosis,and both were confirmed by surgery. Among the 10 patients without bridging vein flow and with liver parenchyma inhomogeneous echo, CEUS showed regionally poor perfusion in the inhomogeneous area, two of which were confirmed by enhanced computed tomography （CT）, but no more additional information about bridging vein flow was provided by enhanced CT. CONCLUSION： CEUS may be a new approach for early diagnosis of postoperative vascular complications after RLDLT, and it can be performed at the bedside.     

Amplitude information from Doppler color flow mapping systems: a preliminary study of the power mode

The flow of a saline-glycerin solution with sand particles through a continuous in vitro flow system was imaged by using two commercially available Doppler color flow mapping systems in a power mode (Toshiba SSH-160A and Advanced Technology Laboratories [ATL] Ultramark 9). The images generated from seven solutions with particle concentrations ranging from 0.0001 x 10(12) to 6 x 10(12) particles/liter and a mean velocity of 30 cm/s measured with use of pulsed Doppler ultrasound were used to examine the dependence of the power mode on particle concentration. To examine the velocity dependence, 20 mean velocities ranging from 0.1 to 0.53 m/s (3 to 30 liters/min) and three particle concentrations (1, 3 and 6 x 10(12) particles/liter) in the solution were used. The recorded images were digitized and analyzed off-line. The SUM values, or the adjusted color intensity levels in delineated areas of interest in the displayed flow, were compared. In general, the power mode was sensitive in displaying slower velocity flows; in the selected particle concentration and velocity ranges, it was both velocity and concentration dependent. The specific dependence differed for the two color flow mapping systems.     

Doppler sonography in the diagnosis of inflammatory bowel disease

Over the past few years, thanks to its ability to reveal neovascularization and inflammatory hyperemia, Doppler sonography has proved to be a valuable method for the assessment of disease activity in inflammatory bowel disease. Hypervascularization has been detected by Doppler imaging both in splanchnic vessels, in terms of flow volume and velocity, or resistance and pulsatility index on spectral analysis, and in small vessels of the affected bowel wall in terms of vessel density. In particular, power Doppler has been shown to be a highly sensitive method for evaluating the presence of flow in vessels that are poorly imaged by conventional color Doppler, and in detecting internal fistulas complicating Crohn's disease. Recently, the use of ultrasound contrast agents, such as Levovist, has been shown to improve the image quality of color Doppler by increasing the backscattered echoes from the desired regions, thus making it possible to better monitor the response to treatment and discriminate between active inflammatory and fibrotic bowel wall thickness in Crohn's disease. Additionally, Levovist-enhanced power Doppler sonography has proved to be highly sensitive and specific in the detection of inflammatory abdominal masses associated with Crohn's disease. In clinical practice, used in combination with second harmonic imaging and new generations of stable contrast agents, Doppler sonography appears to be a non-invasive and effective diagnostic tool in the diagnosis and follow-up of Crohn's disease and ulcerative colitis.     

Endoscopic Doppler ultrasound for measurement of azygos blood flow. Validation against thermodilution and assessment of pharmacological effects of terlipressin in portal hypertension

BACKGROUND: Endoscopic ultrasound (EUS) is a new modality allowing real-time flow measurements by means of the Doppler technique. The aim of the study was to evaluate azygos blood flow measurements by endoscopic ultrasound. METHODS: Measurements of azygos blood flow by EUS and by the thermodilution technique were compared in 20 patients with portal hypertension. The ability of EUS flowmetry to detect changes in the azygos and portal venous flow after an intravenous dose of 2 mg of terlipressin was evaluated in 13 of the patients in a double-blind, randomized, placebo-controlled, cross-over design. RESULTS: The EUS Doppler and thermodilution measurements correlated significantly (R=0.81, P < 0.001). The azygos blood flow was found to be 14% higher by the EUS method than by thermodilution. The coefficient of variation of the EUS Doppler measurements of the azygos blood flow was 14.8%. After administration of terlipressin, the azygos blood flow, as measured by EUS Doppler, decreased significantly by 23% from 915 to 704 ml/min (P = 0.014) and the portal venous flow decreased by 28% from 1170 to 789 ml/min (P = 0.03). No effects of placebo were detected. CONCLUSIONS: These results show that EUS measurement of the azygos blood flow correlate strongly to the measurements by the thermodilution technique, and EUS is moreover well tolerated by the patients. The method is applicable for monitoring pharmacological effects on the superior porto-systemic collateral circulation and portal venous flow in patients with portal hypertension.