Comparison of hand-held acoustic Doppler with point-of-care portable color Doppler ultrasound in the assessment of venous reflux disease.

OBJECTIVE: Diagnostic-quality portable color Doppler ultrasound (PCD) offers convenient point-of-care venous reflux disease (VRD) diagnosis. Philips Lumify (Philips N.V., Best, The Netherlands), a high-fidelity broadband linear array transducer (4-12 MHz frequency), connects through a web-enabled smartphone or tablet to cloud software and offers B-mode and color Doppler imaging without pulsed wave Doppler capability. The aims of the study were to compare hand-held acoustic Doppler (HHD) vs PCD diagnostic performance using conventional duplex ultrasound (DUP) as the "gold standard" for VRD assessment, to assess effects of body mass index (BMI) and disease severity on diagnostic performance of HHD and PCD, and to determine whether PCD offers any diagnostic improvement over HHD in VRD assessment. METHODS: There were 241 patients (65 male, 176 female; mean age, 55.5 ± 15.5 years; mean BMI, 32.2 ± 7.9 kg/m2). DUP (447 legs), PCD (262 legs), and HHD (217 legs) studied the great saphenous vein at above-knee (AK) and below-knee (BK) levels. A phlebologist performed HHD, whereas PCD and DUP were performed sequentially (PCD first) by an experienced technologist and interpreted independently. PCD was done blinded to DUP results. DUP findings were analyzed blinded to HHD and PCD results. Venous reflux was dichotomously assessed as <2 seconds and >2 seconds. RESULTS: HHD improves from moderate to good sensitivity from AK level (68%) to BK level (94%) but suffers poor specificity that declines significantly from AK level (50%) to BK level (12%; P < .05). HHD positive predictive value exceeds its negative predictive value (NPV) and remains unchanged from AK level (71%) to BK level (72%). HHD NPV remains consistently poor at AK (48%) and BK (42%) levels. PCD has similar sensitivity from AK level (69%) to BK level (74%), better AK level (79%) vs BK level (58%) specificity (P < .05), similar positive predictive value for AK (76%) and BK levels (78%), and better NPV for AK level (72%) vs BK level (53%; P < .05). BMI range (<30 kg/m2 vs ≥ 30 kg/m2) did not influence diagnostic performance of HHD and PCD significantly. HHD and PCD specificity was higher for Clinical, Etiology, Anatomy, and Pathophysiology (CEAP) class <4 compared with CEAP class ≥4 (P < .05). CONCLUSIONS: The relative diagnostic performance of HHD and PCD is highly dependent on insonation level. PCD advantages compared with HHD are marginally greater specificity at AK and BK levels and better NPV at AK level. Compared with HHD, PCD's disadvantage is lower sensitivity at BK level. Both HHD and PCD have higher specificity at AK level than at BK level. Overall, PCD offers only moderate sensitivity and specificity, making it inadequate for exclusion of significant venous reflux. Neither obesity nor CEAP class significantly influenced the general diagnostic performance of PCD or HHD.

[Quality standards for ultrasonographic assessment of peripheral vascular malformations and vascular tumors. Report of the french society for vascular medicine. 2018 Update]. / Standards de qualité pour la pratique de l'examen écho-Doppler dans l'étude des malformations et tumeurs vasculaires. Rapport de la Société française de médecine vasculaire (SFMV) : actualisation 2018.

The quality standards of the French Society of Vascular Medicine for the ultrasonographic assessment of vascular malformations are based on the two following requirements: (1) technical know-how: mastering the use of ultrasound devices and the method of examination; (2) medical know-how: ability to adapt the methods and scope of the examination to its clinical indication and purpose, and to rationally analyze and interpret its results. AIMS OF THE QUALITY STANDARDS: To describe an optimal method of examination in relation to the clinical question and hypothesis. To homogenize practice, methods, glossary, and reporting. To provide good practice reference points, and promote a quality process. ITEMS OF THE QUALITY STANDARDS: The 3 levels of examination; their clinical indications and goals. The reference standard examination (level 2), its variants according to clinical needs. The minimal content of the examination report; the letter to the referring physician (synthesis, conclusion and proposal for further investigation and/or therapeutic management). Commented glossary (anatomy, hemodynamics, semiology). Technical bases. Setting and use of ultrasound devices. Here, we discuss ultrasonography methods of using of ultrasonography for the assessment of peripheral vascular malformations and tumors (limbs, face, trunk).

Standardized Protocol for Hemodialysis Vascular Access Assessment: The Role of Ultrasound and ColorDoppler.

INTRODUCTION: Ultrasound and colorDoppler technique, which is relatively inexpensive, rapid, non-invasive and repeatable is a powerful tool used for early diagnosis of vascular access (VA) complications in hemodialysis patients. To date a standard and widely comprehensible echocolorDoppler (ECD) protocol is not available. MATERIALS AND METHODS: A simple step-by-step protocol based on anatomical and hemodynamic parameters of VA has been developed during a 3-years VA ECD follow-up. It consists of an ECD study scheme. The algorithm created involves the calculation of brachial artery flow, description of artero-venous and/or graft-vascular anastomosis and efferent vessel and/or graft. RESULTS: The algorithm allows to formulate a medical report that takes into account both anatomic and hemodynamic parameters of the VA. Reduction of complications and the prevention of chronic complications as well as the early detection of acute problems were achieved. DISCUSSION AND CONCLUSION: The creation of a step-by-step protocol may simplify the multidisciplinary management of VA, its monitoring and the early diagnosis of its complications.

[Innovative Ultrasound: Contrast-Enhanced Ultrasound of the Kidneys]. / Innovativer Ultraschall: Kontrastverstärkter Ultraschall der Nieren.

Ultrasound examination of the kidneys with grey-scale imaging and colour Doppler ultrasound is the most common renal imaging modality. A few years ago, contrast-enhanced ultrasound (CEUS) emerged as a non-invasive perfusion imaging modality to evaluate the renal vessels and microvascularisation. These contrast media contain intravenous microbubbles (sulfur hexafluoride), which have no deleterious effect on renal function. Being free of iodine, they also pose no risk for the thyroid gland. CEUS of the kidneys is mainly used for the evaluation of renal cysts and the analysis of renal lesions suspicious for malignancy. Also this method is used to visualise inflammation as well as renal perfusion after trauma or infarction.

Sistemática para el estudio Doppler de carótidas / Systematic assessment in carotid doppler ultrasound

La exploración de los ejes carotideo y vertebral resulta sencilla técnicamente, con un aprendizaje relativamente rápido para el que inicia la actividad, especialmente si se establecen protocolos de exámenes estandarizados y fácilmente reproducibles. El objetivo de la sistematización en los servicios de Doppler vascular es que los exámenes realizados por distintos operadores sean similares en cuanto a la técnica y la terminología del informe; a nivel docente la sistematización ofrece al neófito una metodología clara a seguir con el fin de completar las evaluaciones y solidificar el proceso de aprendizaje.

Ultrasonographic assessment of tendon thickness, Doppler activity and bony spurs of the elbow in patients with lateral epicondylitis and healthy subjects: a reliability and agreement study.

PURPOSE: Tennis elbow, also known as lateral epicondylitis (LE), is a common disorder often assessed by ultrasound. The aim of this study was to evaluate the ultrasonographic outcomes and methods used in LE research and clinical practice. MATERIALS AND METHODS: This study was designed as an intra- and interobserver reliability and agreement study. Ultrasonographic examination of the common extensor tendon of the elbow was performed. The intraobserver study examined tendon thickness twice in 20 right elbows from 20 healthy individuals at an interval of 7 to 12 days. The interobserver study examined tendon thickness, color Doppler activity, and bony spurs in 18 right elbows in 9 healthy individuals and 9 patients with LE. Two trained rheumatologists performed the interobserver examinations with the same scanner on the same day. The main outcomes were intra- and interclass correlation (ICC) and agreement. RESULTS: In the intraobserver study, the ICC with regard to tendon thickness ranged from 0.76 to 0.81, depending on the measurement techniques used. The agreement ranged from 0.06 to 0.13 mm. In the interobserver study, the tendon thickness ICC ranged from 0.45 to 0.65 and the agreement ranged from -0.17 to 0.13 mm. The ICC for color Doppler activity was 0.93, with agreement in 14/18 (78 %) of the cases. A perfect reliability was demonstrated for bony spurs, with an ICC of 1 and exact agreement in 18/18 (100 %) of the cases. CONCLUSION: Good to excellent reliability was obtained for all measurements. The ultrasonographic techniques evaluated in this trial can be recommended for use in both research and clinical practice.

A low-cost, durable, combined ultrasound and fluoroscopic phantom for cervical transforaminal injections.

BACKGROUND: This technical report describes a durable, low-cost, anatomically accurate, and easy-to-prepare combined ultrasound (US) and fluoroscopic phantom of the cervical spine. This phantom is meant to augment training in US- and fluoroscopic-guided pain medicine procedures. METHODS: The combined US and fluoroscopic phantom (CUF-P) is prepared from commercially available liquid plastic that is ordinarily used to prepare synthetic fishing lures. The liquid plastic is heated and then poured into a metal canister that houses an anatomical cervical spine model. Drops of dark purple dye are added to make the phantom opaque. After cooling, tubing is attached to the CUF-P to simulate blood vessels. RESULTS: The CUF-P accurately simulates human tissue by imitating both the tactile texture of skin and the haptic resistance of human tissue as the needle is advanced. This phantom contains simulated fluid-filled vertebral arteries that exhibit pulsed flow under color Doppler US. Under fluoroscopic examination, the CUF-P-simulated vertebral arteries also exhibit uptake of contrast dye if mistakenly injected. CONCLUSIONS: The creation of a training phantom allows the pain physician to practice needle positioning technique while simultaneously visualizing both targeted and avoidable vascular structures under US and fluoroscopic guidance. This low-cost CUF-P is easy to prepare and is reusable, making it an attractive alternative to current homemade and commercially available phantom simulators.

Use of a high-frequency linear transducer and MTI filtered color flow mapping in the assessment of fetal heart anatomy at the routine 11 to 13 + 6-week scan: a randomized trial.

OBJECTIVE: To prospectively assess the contribution of a high-frequency linear transducer and of moving target indicator (MTI) filtered color flow mapping in the visualization of cardiac fetal anatomy at the routine 11 to 13 + 6-week scan. METHODS: This was a cross-sectional prospective study, including 300 singleton fetuses at 11 to 13 + 6 weeks' gestation. Patients were randomized into four groups and a detailed fetal cardiac examination was conducted transabdominally using either a conventional curvilinear transducer, a conventional curvilinear transducer and MTI filtered color flow mapping, a high-frequency linear transducer or a high-frequency linear transducer and MTI filtered color flow mapping. Regression analysis was used to investigate the effect on the ability to visualize different cardiac structures of the following parameters: gestational age at ultrasound examination; fetal crown-rump length (CRL); maternal body mass index (BMI); transducer-heart distance; the technique used at ultrasound; and the position of the placenta. RESULTS: The four-chamber view was visualized in 89.0% of fetuses and regression analysis showed this rate was correlated with CRL and the use of MTI filtered color flow mapping during ultrasonography, and inversely correlated with BMI and transducer-heart distance. Use of a conventional curvilinear transducer and MTI filtered color flow mapping allowed visualization of the four-chamber view in 97.3% of fetuses, while this was only possible in 84.0% of fetuses using a high-frequency linear transducer. The left and right outflow tracts were visualized in 62.3 and 57.7% of fetuses, respectively. Regression analysis showed that the ability to visualize the left or the right outflow tract was correlated with the use of MTI filtered color flow mapping during scanning and was inversely correlated with transducer-heart distance. The use of a conventional curvilinear transducer and MTI filtered color flow mapping allowed visualization of the left and right outflow tracts in 96.0 and 97.3% of fetuses, respectively, while this was only possible in 37.3 and 26.7% of fetuses using a high-frequency linear transducer. CONCLUSIONS: During the routine 11 to 13 + 6-week scan, the use of MTI filtered color flow mapping but not of a high-frequency linear transducer, improves visualization of cardiac anatomy.

Noninvasive assessment of liver fibrosis with acoustic radiation force impulse imaging: increased liver and splenic stiffness in patients with liver fibrosis and cirrhosis.

PURPOSE: To evaluate acoustic radiation force impulse imaging (ARFI) of the liver and spleen as a new method for the noninvasive assessment of liver fibrosis (LF). MATERIALS AND METHODS: Three groups of 58 examinees were studied: (A) 20 healthy volunteers; (B) 18 patients with chronic viral hepatitis (CVH) B or C having liver fibrosis stages F 1 - 4 (assessed by liver biopsy; Ishak classification); and (C) 20 patients with liver cirrhosis (LC). All participants were examined using the Siemens ACUSON S 2000 Ultrasound Virtual Touch Tissue Quantification system. Ten measurements were performed on both liver lobes and three measurements on the spleen, and the obtained mean values (shear wave velocities [SWV] expressed in m/s) were compared between the groups. In 20 patients the splenic artery pulsatility index (SAPI) was also measured and correlated to the liver and splenic ARFI and histological stage of LF. RESULTS: Hepatic ARFI measurements demonstrated a significant correlation to LB results (Spearman's ρ = 0.766; ρ < 0.001) and SWV cut-off values of 1.3 (AUC 0.96) and 1.86 (AUC 0.99) could reliably differentiate between healthy (A) and non-cirrhotic CVH (B), as well as between non-cirrhotic CVH (B) and LC (C). Splenic SWV cut-off value of 2.73 (AUC 0.82) could differentiate between the patients with LC and non-cirrhotic CVH. A significant correlation was also observed between the SAPI and liver ARFI results (ρ = 0.56; p = 0.013). CONCLUSION: The hepatic and splenic SWV measured by ARFI increase with the LF stage, and the hepatic SWV correlate well with SAPI. This new technology enables simultaneous morphological, Doppler and elastometric examinations and might improve the accuracy of noninvasive liver fibrosis assessment.

The assessment of microvascular flow and tissue perfusion using ultrasound imaging.

Imaging microvascular flow is of diagnostic value for a wide range of diseases including cancer, inflammation, and cardiovascular disease. The introduction of microbubbles as ultrasound contrast agents offers significant signal enhancement to the otherwise weakly scattered signal from blood in the circulation. Microbubbles provide maximum impedance mismatch, but are not linear scatterers. Their complex response to ultrasound has generated research on both their behaviour and their scattered-signal processing. Nearly 20 years ago signal processing started with simple spectral filtering of harmonics showing contrast-enhanced images. More recent pulse encoding techniques have achieved good cancellation of tissue echoes. The good quality contrast-only images enabled ultrasound contrast-imaging applications to be established in microvascular measurements in the liver and the myocardium. The field promises to advance the quantification of microvascular flow kinetics.

Practical knobology for ultrasound-guided regional anesthesia.

This article provides an instructive review of the essential functions universal to modern ultrasound machines in use for regional anesthesia practice. An understanding of machine knobology is integral to performing safe and successful ultrasound-guided regional anesthesia.

Assessment of numerical simulation strategies for ultrasonic color blood flow imaging, based on a computer and experimental model of the carotid artery.

Ultrasonic Doppler techniques are well established and allow qualitative and quantitative flow analysis. However, due to inherent limitations of the imaging process, the actual flow dynamics and the ultrasound (US) image do not always correspond. To investigate the performance of ultrasonic flow imaging methods, computational fluid dynamics (CFD) can play an important role. CFD simulations can be directly processed to mimic ultrasonic images or can be further coupled to ultrasound simulation models. We studied both approaches in the clinically relevant setting of a carotid artery using color flow images (CFI). The first order approach consisted of producing ultrasound images by color-coding CFD-simulations. For the second order approach, CFI was simulated using an ultrasound simulator, which models blood as a collection of point scatterers moving according to the CFD velocity fields. Color flow images were also measured in an experimental setup of the same carotid geometry for comparison. Results showed that during dynamic stages of the cardiac cycle, realistic ultrasound data can only be achieved when incorporating both the dynamic image formation and the measurement statistics into the simulations.

[Basic characteristics of duplex sonography in the assessment of lower limb arterial circulation].

INTRODUCTION: Dulpex and color duplex ultrasonography of lower limb arteries are valuable non-invasive diagnostic methods in the pathology of vascular diseases and a major step in diagnostics and in follow-up of hemodynamic and morphologic characteristics. COLOR DUPLEX SONOGRAPHY: The method consists of image analysis and analysis of Doppler information. Real-time-B mode is used to visualize the anatomy of blood vessels and other pathological lesions. Doppler information based on the Doppler effect determine the pulse wave i.e. the shape of flow velocity--hemodynamic characteristics. Spectral analysis is the most important element of Doppler examination of the lower limb peripheral arteries. Based on the spectral analysis, there are four stages of lower limb arterial disease: normal findings--1% - 19% diameter reduction; medium stenosis--artery diameter reduction of 20% - 49%; high level stenosis--artery diameter reduction of 50% - 100%; occlusion--no flow detected within the imaged arterial segment. In the first place, both iliac arteries are examined, which is followed with femoral, popliteal and crural arteries. The examination of iliac arteries is carried out with a 3.5 MHz transducer, and other peripheral arteries of the lower limbs are examined with a 7, 5 or 5 MHz transducer. CONCLUSION: Color Doppler is an extremely valuable diagnostic method in detecting pathology of the lower limb arteries. With high reliability level arterial insufficiency and pathological arterial segments are diagnosed by a duplex-Doppler.

Hand-held thoracic sonography for detecting post-traumatic pneumothoraces: the Extended Focused Assessment with Sonography for Trauma (EFAST).

BACKGROUND: Thoracic ultrasound (EFAST) has shown promise in inferring the presence of post-traumatic pneumothoraces (PTXs) and may have a particular value in identifying occult pneumothoraces (OPTXs) missed by the AP supine chest radiograph (CXR). However, the diagnostic utility of hand-held US has not been previously evaluated in this role. METHODS: Thoracic US examinations were performed during the initial resuscitation of injured patients at a provincial trauma referral center. A high frequency linear transducer and a 2.4 kg US attached to a video-recorder were used. Real-time EFAST examinations for PTXs were blindly compared with the subsequent results of CXRs, a composite standard (CXR, chest and abdominal CT scans, clinical course, and invasive interventions), and a CT gold standard (CT only). Charts were reviewed for in-hospital outcomes and follow-up. RESULTS: There were 225 eligible patients (207 blunt, 18 penetrating); 17 were excluded from the US examination because of battery failure or a lost probe. Sixty-five (65) PTXs were detected in 52 patients (22% of patients), 41 (63%) being occult to CXR in 33 patients (14.2% whole population, 24.6% of those with a CT). The US and CXR agreed in 186 (89.4%) of patients, EFAST was better in 16 (7.7%), and CXR better in 6 (2.9%). Compared with the composite standard, the sensitivity of EFAST was 58.9% with a likelihood ratio of a positive test (LR+) of 69.7 and a specificity of 99.1%. Comparing EFAST directly to CXR, by looking at each of 266 lung fields with the benefit of the CT gold standard, the EFAST showed higher sensitivity over CXR (48.8% versus 20.9%). Both exams had a very high specificity (99.6% and 98.7%), and very predictive LR+ (46.7 and 36.3). CONCLUSION: EFAST has comparable specificity to CXR but is more sensitive for the detection of OPTXs after trauma. Positive EFAST findings should be addressed either clinically or with CT depending on hemodynamic stability. CT should be used if detection of all PTXs is desired.

Comparison of color-flow Doppler scanning, power Doppler scanning, and frequency shift for assessment of carotid artery stenosis.

OBJECTIVE: We investigated the accuracy of color-flow Doppler (CD) scanning, power Doppler (PD) scanning, and peak systolic Doppler frequency shift (PSF) in assessment of carotid artery stenosis with angiography used as gold standard, including the measurement techniques used in the North American Symptomatic Carotid Surgery Trial (NASCET) and the European Carotid Surgery Trial (ECST). METHODS: Fifty-eight consecutive patients diagnosed for carotid artery surgery underwent color-coded duplex sonography and angiography. The duplex examination included the assessment of PSF and the videotaping of sagittal images in CD and PD mode from the proximal common carotid artery to the distal internal carotid artery. Two experienced examiners performed the studies, but once one examiner had done the taping, the other examiner was allowed only to review the tape. Separately, each examiner reviewed the tapes and determined by cursor settings each stenosis according to NASCET and ECST. For interobserver agreement kappa statistic was used. To compare with angiography (degree of stenosis 40%, 50%, 60%, 70%, and 80%) sensitivity, specificity, positive and negative predictive values, and overall accuracy were calculated. PSF cut-off frequencies were based on receiver operator curve analysis. RESULTS: Because interobserver agreement in CD and PD was good (chance-corrected kappa > 0.6), further analysis used the between-observer mean value for each stenosis. With the NASCET measurement technique, accuracy of Doppler techniques to distinguish a 50% stenosis was 89% for PSF, 91% for CD, and 93% for PD; for a 70% stenosis it was 83% for PSF, 84% for CD, and 81% for PD. With the ECST measurement technique, accuracy to distinguish a 70% stenosis was 86% for PSF, 88% for CD, and 86% for PD; for an 80% stenosis it was 87% for PSF, 87% for CD, and 77% for PD. CONCLUSION: CD and PD carotid artery stenosis measurements are highly reproducible, and in our hands provided accuracy equal to PSF.

Noninvasive assessment of vocal fold mucosal wave velocity using color doppler imaging.

The vibratory movement of the vocal folds (VF) plays an important role in normal function of phonation. We developed a noninvasive technique to quantify the human mucosal wave velocity (MWV) in vivo using color Doppler imaging (CDI). During phonation, the motion of mucosa-air interface generates a unique pattern of US color artefacts that assist the identification of true VF location. An in vitro study using a vibrating string phantom was conducted to investigate how the CDI displayed a vibrating soft tissue at high frequency. The vibrating amplitude, frequency, mass density and the acoustic impedance of the soft tissues were found to dominate the formation of color artefacts. Based on the model of finite string with fixed ends, we estimated the mean MWV for 10 adult volunteers (6 men, 4 women, ages 34 +/- 5 years) with normal VF function. The mean MWVs for the men were found to vary from 2.1 to 10 m/s in a frequency range of 85 to 310 Hz at their comfortable pitch and intensity, and the women typically had higher MWVs that varied from 5.0 to 16.5 m/s in a frequency range of 180 to 480 Hz. The MWV increased linearly with the frequency and there was no observable difference in mucosa stiffness due to the effect of gender. The variation in MWV as it propagates vertically can be seen from the color and shape of the artefacts. The VF polyp resulted in abnormal MWV and different CDI vibratory artefacts. The CDI artefacts provide insight on the dynamics of mucosa structure during phonation, and the method presented is promising for noninvasive monitoring of laryngeal functions clinically.

Assessment of carotid wall motion and stiffness with tissue Doppler imaging.

In this study, the wall motion of the common carotid artery was characterized by measuring wall-motion velocity (Wv) with tissue Doppler imaging (TDI) in 78 male and female subjects (16-75 y) with no history of cardiovascular disease. The near and far arterial wall showed essentially different Wv patterns. To assess the vascular systolic distension, the Wv of the near and far arterial walls were measured and a Wv index was calculated by subtracting the far Wv from the near Wv. Aging was associated with a 2.0-2.5-fold decrease of peak Wv index. Corrected for carotid diameter and blood pressure, the peak Wv index and mean systolic acceleration to the peak Wv correlated highly with arterial distensibility (r = 0.81 resp. r = 0.75) and compliance (r = 0.73 resp. r = 0.68). This study demonstrates the feasibility of TDI in the characterization of wall motion patterns and in the assessment of common carotid artery stiffness.

Assessment of internal thoracic artery graft with intraoperative color Doppler ultrasonography.

BACKGROUND: Intraoperative ultrasonography has the potential to provide anatomic and functional information about internal thoracic artery (ITA) graft, but this potential has been hindered by the relatively large standard probe. In this study, we used a color Doppler microprobe to evaluate ITA grafts. METHODS: The subjects were 15 consecutive patients who underwent elective coronary artery bypass grafting either with cardiopulmonary bypass (n = 14) or without (n = 1). All patients underwent anastomosis of the left ITA to the left anterior descending artery. The ITA graft was assessed before the chest was closed, with the microprobe placed directly on the graft. RESULTS: A good-quality color Doppler image of the ITA graft was easily obtained in all 15 patients within a few minutes. The ITA graft function was assessed by analyzing the shape of the pulsed Doppler wave. All ITA grafts were patent, and the mean graft diameter was 1.8 +/- 0.04 mm. The peak systolic velocity, peak diastolic velocity, and mean velocity were 52.0 +/- 14.9 cm/s, 58.3 +/- 22.4 cm/s, and 36.5 +/- 10.9 cm/s, respectively. The ratio of peak diastolic velocity to peak systolic velocity was 1.24 +/- 0.66. The ITA graft seemed to function well when the biphasic diastolic predominant flow appeared. The mean blood flow was 55.1 +/- 22.0 mL/min. CONCLUSIONS: Intraoperative ultrasonography using the microprobe provides adequate anatomic and hemodynamic information regarding ITA grafts. As the Doppler flow evaluation has high sensitivity and specificity, we suggest that intraoperative ultrasonography is useful for the assessment of these grafts.

Color Doppler imaging of the eye and orbit.

Since the development of A- and B-scan ultrasound technique in the 1950s, significant progress in ophthalmic ultrasound has appeared. As the technology advances and ultrasound systems improve their ability to acquire and detect ultrasonic signals and to analyze them in terms of a spatial resolution and frequency distribution, there is no doubt that the extent of clinical applications will expand accordingly. Nevertheless, the fundamental physical restrictions of ultrasonography and Doppler will always remain the same. For ophthalmology, we hope that less expensive color Doppler systems with specifically designed probes, improved two-dimensional resolution, and Doppler spectrum acquisition will become more widely available. Because CDI allows for the first time a noninvasive assessment of the retrobulbar vasculature, we feel that many applications of this technology will develop for ophthalmology.