Color Flow Imaging Research Articles

Grading Carotid Stenosis Using Ultrasonic Methods

The controversy as to whether Doppler ultrasonic methods should play a role in clinical decision-making in the prevention of stroke is attributable to reported disagreement between angiographic and ultrasonic results and the lack of internationally accepted ultrasound criteria for describing the degree of stenosis. Foremost among the explanations for both is the broad scatter of peak systolic velocities in the stenosis, the criterion that has so far received most attention. Grading based on a set of main and additional criteria can overcome diagnostic errors. Morphological measurements (B-mode images and color flow imaging) are the main criteria for low and moderate degrees of stenosis. Increased velocities in the stenosis indicate narrowing, but the appearance of collateral flow and decreased poststenotic flow velocity prove a high degree stenosis (≥70%), additionally allowing the estimation of the hemodynamic effect in the category of high-degree stenosis. Additional criteria refer to the effect of a stenosis on prestenotic flow (common carotid artery), the extent of poststenotic flow disturbances, and derived velocity criteria (diastolic peak velocity and the carotid ratio). This multiparametric approach is intended to increase the reliability and the standard of reporting of ultrasonic results for arteriosclerotic disease of the carotid artery.

Abstract 2959: Diagnosis of Right-to-Left Shunt in Intracranial Vertebral Artery by Transcranial Color Flow Imaging

Objective: Right-to-Left shunt (RLS) detection by Transcranial Doppler is useful for diagnosis of paradoxical embolism. However, we sometimes could not monitor MCA due to insufficient temporal bone window, especially in old patients. Other insonation windows such as transorbital and suboccipital window (basilar artery) are using recently, whereas the ability to detect of intracranial arteries from these windows was not so high. We evaluated usefulness of RLS detection in intracranial vertebral artery (VA) from suboccipital approach that could be measured in almost patients. Methods: We evaluated RLS using transcranial color flow imaging (TC-CFI) in patients with ischemic stroke or transient ischemic attack who could be detected middle cerebral artery (MCA) from temporal bone window and intracranial VA from suboccipital window by TC-CFI. We monitored microembolic signal (MES) at ipsilateral MCA and VA (not hypoplastic side) for 90seconds after injection of 9ml saline agitated with 1ml of air in the right antecubital vein. The procedure was performed three times in each artery with and without Valsalva maneuver. The presence of MES was classified according to Spencer Logarithmic Scale (SLS) criteria. Results: Fifty two patients (46 male, mean age of 64.1±14.3) were included. Twelve patients were positive of MES (23.1%). VA comparison to MCA showed 10 true positive, 40 true negative, 0 false positive and 2 false negative cases (sensitivity 83.3%, specificity 100%, positive predictive value 100%, negative predictive value 95.2% and accuracy 96.2%). In 12 patients with MES, 22 of 36 examinations in MCA were positive of MES (SLS grade I was 20 examinations and grade II was 2 examinations), on the other hand, 20 of 36 examinations in VA were positive (SLS grade I was 20 examinations). The positive ratio of 36 examinations in 12 patients did not show significant difference statistically between MCA and VA. Conclusion: The evaluation of RLS in intracranial VA using TC-CFI from suboccipital window has equal diagnostic ability to MCA, and is useful for the patients with insufficient temporal bone window.

Transesophageal echocardiography: Instrumentation and system controls

Transesophageal echocardiography (TEE) is a semi-invasive, monitoring and diagnostic tool, which is used in the perioperative management of cardiac surgical and hemodynamically unstable patients. The low degree of invasiveness and the capacity to visualize and assimilate dynamic information that can change the course of the patient management is an important advantage of TEE. Although TEE is reliable, comprehensive, credible, and cost-effective, it must be performed by a trained echocardiographer who understands the indications and the potential complications of the procedure, and has the ability to achieve proper acquisition and interpretation of the echocardiographic data. Adequate knowledge of the physics of ultrasound and the TEE machine controls is imperative to optimize image quality, reduce artifacts, and prevent misinterpretation of diagnosis. Two-dimensional (2D) and Motion (M) mode imaging are used for obtaining anatomical information, while Doppler and Color Flow imaging are used for information on blood flow. 3D technology enables us to view the cardiac structures from different perspectives. Despite the recent advances of 3D TEE, a sharp, optimized 2D image is pivotal for the reconstruction. This article describes the relevant underlying physical principles of ultrasound and focuses on a systematic approach to instrumentation and use of controls in the practical use of transesophageal echocardiography.

Sonography of gangrenous cholecystitis

Gangrenous cholecystitis is an acute surgical emergency, which requires early cholecystectomy. Differentiation of patients with gangrenous cholecystitis from those with non-gangrenous cholecystitis can be difficult, both clinically and with imaging. Careful attention to the following sonographic signs suggests the presence of gangrenous cholecystitis decreased focal wall perfusion on Color Doppler, irregular gall bladder mucosal outline, gall bladder wall thickening with signs of de-lamination, gas within the gall bladder, absence of calculi, and large peri-cholecystic collections. Both sonogram with color flow imaging and contrast-enhanced Computed tomography are complementary investigations to establish this important diagnosis in critically ill patients.

Routinely adding ultrasound examinations by pocket-sized ultrasound devices improves inpatient diagnostics in a medical department

BackgroundWe aimed to investigate the potential benefit of adding a routine cardiac and abdominal diagnostic examination by pocket-sized ultrasound device in patients admitted to a medical department. MethodsA random sample of 196 patients admitted to the medical department at a non-university hospital in Norway between March and September 2010 was studied. The patients underwent cardiac and abdominal screening with a pocket-sized ultrasound device with B-mode and color flow imaging after a principal diagnosis was set. Three internists/cardiologists experienced in ultrasonography performed the examinations. Diagnostic corrections were made and findings were confirmed by high-end echocardiography and examinations at the radiologic department. Results196 patients were included (male=56.6%, mean±SD; 68.1±15.0years old). The time spent doing the ultrasound screening was mean±SD 4.3±1.6min for the cardiac screening and 2.5±1.1min for the abdominal screening. In 36 (18.4%) patients this examination resulted in a major change in the primary diagnosis. In 38 (19.4%) patients the diagnosis was verified and in 18 (9.2%) patients an important additional diagnosis was made. ConclusionBy adding a pocket-sized ultrasound examination of <10min to usual care, we corrected the diagnosis in almost 1 of 5 patients admitted to a medical department, resulting in a completely different treatment strategy without delay in many of the patients. Routinely adding a cardiac and abdominal ultrasound screening has the potential to rearrange inpatients workflow and diagnosis.

Effect of dual-frequency clutter suppression in harmonic Doppler detection

Background High-frequency Doppler imaging is highly potential for detection of blood flow in microcirculation. In a swept-scan system, however, the spectral broadening of tissue clutter limits the detectability of low-velocity flow signal. Conventionally, the scanning speed of transducer has to be reduced to alleviate the clutter interference but at the cost of imaging frame rate. For example, the blood velocity of 0.5 mm/s becomes detectable only with a scanning speed lower than 1 mm/s. In this study, an alternative method is examined by suppressing the clutter magnitude to reduce the interference to flow signal without sacrificing scanning speed. Methods The method of third harmonic (3 f 0) transmit phasing can suppress the tissue harmonic clutter by transmitting at the fundamental and the additional 3 f 0 frequencies to achieve mutual cancellation between the frequency-sum and the frequency-difference components of the second harmonic signal. With 3 f 0 transmit phasing, the cut-off frequency of wall filtering can be reduced to preserve low-velocity flow without compromising the frame rate. Results Our results indicate that the 3 f 0 transmit phasing effectively reduces the harmonic clutter magnitude and thus improves the flow signal-to-clutter ratio. Compared to the conventional counterpart, the clutter-suppressed color flow and power Doppler images show fewer clutter artifacts and is capable of detecting more low-velocity flow of microbubbles. The resultant color-pixel-density also improves with clutter suppression. Conclusion For the swept-scan high-frequency (>20 MHz) system, 3 f 0 transmit phasing is capable of providing effective clutter suppression. With the same achievable scanning speed, the resultant Doppler image has higher sensitivity for low-velocity flow and is less susceptible to clutter artifacts.

Multi imaging approach with low field MRA in diabetic foot ulcer: hospital based study

The aim of study was to assess the usefulness of non-invasive imaging in patient of diabetic foot ulcer with low field MRA and determine the severity and extent of lower extremity arterial disease in diabetic patients with poor socio economic status. The present study is based on 38 patients who were referred to Department of Radiology with complaint of non-healing ulcer of lower limb of more than 6 weeks duration. The patients were subjected to plain radiographs, Duplex scanning with color flow imaging and MR angiography (non contrast enhanced). The modalities were used to detect vascular calcifications, osteomyelitis, bone resorption, deformities, thickening of arteries, plaques, spectral waveforms, collaterals. MRA was used to assess subjective calibre of vessels and presence of stenosis. The patients were categorised according to age and a note of ulcer duration made. Grade of ulcer was determined (wagner’s criteria) and note was made of severity of stenosis (cossman). Radiographs assessed bony destruction and vascular calcification. Doppler assessed degree of stenosis and vascularity. MRI gave a road map of vascular integrity. Integration of the tests provided a satisfactory diagnostic protocol to decide future prognosis and assessment of advancement of disease process. The data was subjected to calculation of mean, standard deviation and Pearson’s chi square test. p value < 0.05 was considered to be stastically significant. Majority of patients were males (80%) and highest incidence was noted in fourth-fifth decade (43.33%). 47.37% presented with grade III ulcer. Duplex scanning with color flow imaging was more accurate and sensitive in picking up calcified arteries, focal plaques, stenosed arteries and abnormal arterial waveforms. These patients had co-existent lower extremity arterial disease with moderate to severe stenosis (i.e. on comparision with peak systolic velocity (PSV), p < 0.05. Ulcer grade had stastically significant correlation with severity of stenosis, (p < 0.05). However MRA did not corroborate the same findings. It proved to be only 60% sensitive when compared to Duplex scanning (100%). Plain radiographs and color Doppler evaluation plays an indispensable role in imaging and evaluating patients with chronic non-healing ulcer of diabetic foot. MRA gives crucial information regarding parameters like vascularity, degree of stenosis, and extent of disease. Not all patients in our set up afford CTA or CEMRA followed by DSA or cost of stenting. When the diagnostic workup in our cases suggested poor prognosis or non salvageable vascular compromise the patient was counseled against further investigation and advised surgery. By using this approach many financially constrained patients are benefitted from unnecessary and costly diagnostic workup.

Clinical application of a micro multiplane transoesophageal probe in congenital cardiac disease

To assess the quality of imaging modalities of a new micro multiplane transoesophageal echocardiogram probe. This is a prospective study of micro transoesophageal echocardiogram S8-3t probe used at a single institution between 15 December, 2009 and 15 March, 2010. The images were compared with standard paediatric or adult probes where possible. Assessors prospectively rated imaging quality - two dimensional, colour flow imaging, pulse wave, and continuous wave Doppler - with a subjective 4-point scale (1 = poor to 4 = excellent). A total of 24 studies were performed on 23 patients, with a median weight = 11.7 kilograms (2.6-72 kilograms) and a median age of 3 years (0.16-60 years). Of the 23 patients, one neonate (2.8 kilograms) had transient bradycardia on probe insertion. Imaging in patients less than 10 kilograms was of full diagnostic value and new information was obtained in eight out of ten patients. Pulse wave and continuous wave Doppler was consistently good across all weight groups. There were high frame rates and good imaging quality to a depth of 4-6 centimetres in all studies. A comparison with a larger alternative probe was available for 12 studies (weight 11.9-72 kilograms). The median micro transoesophageal two-dimensional image quality score was 3 (2-4) and 4 (3-4) with the comparative probe. For the 10- to 30-kilogram group, image quality with the micro transoesophageal echocardiogram probe was judged as inferior to larger standard probes. Adult sized patients had good imaging of near the field, allowing guidance for percutaneous device closure of the atrial septum. The micro multiplane transoesophageal echocardiogram probe provides imaging of diagnostic quality in neonates. In larger patients, it offers good imaging of near field structures. In the intermediate-sized child (10-30 kilograms), standard paediatric probes provide better imaging.

A Single-Ensemble Clutter Rejection Method Based on the Analytic Geometry for Ultrasound Color Flow Imaging

In ultrasound color flow imaging (CFI), the single-ensemble eigen-based filters can reject clutter components using each slow-time ensemble individually. They have shown excellent spatial adaptability. This article proposes a novel clutter rejection method called the single-ensemble geometry filter (SGF), which is derived from an analytic geometry perspective. If the transmitted pulse number M equals two, the clutter component distribution on a two-dimensional (2-D) plane will be similar to a tilted ellipse. Therefore, the direction of the major axis of the ellipse can be used as the first principal component of the autocorrelation matrix estimated from multiple ensembles. Then the algorithm is generalized from 2-D to a higher dimensional space by using linear algebra representations of the ellipse. Comparisons have been made with the high-pass filter (HPF), the Hankel-singular value decomposition (SVD) filter and the recursive eigen-decomposition (RED) method using both simulated and human carotid data. Results show that compared with HPF and Hankel-SVD, the proposed filter causes less bias on the velocity estimation when the clutter velocity is close to that of the blood flow. On the other hand, the proposed filter does not need to update the autocorrelation matrix and can achieve better spatial adaptability than the RED.

The Enemy of Good …

The Enemy of Good …

Ultrafast Ultrasound Imaging

Ultrasound can be considered as a disruptive technology in the medical device arena (Christensen, 2003). A disruptive technology has the potential to break the rules of existing markets. Thanks to its real time capabilities, its non ionizing properties and its cost much lower than any other medical modality ultrasound has significantly impacted clinical segments within radiology, obstetrics, vascular or cardiology and created new markets of emergency medicine and intervention. It could, in the future, change the rules for screening (where whole breast ultrasound devices are entering the market of breast imaging), diagnosis (with the standardization of elastography techniques in the prostate) and surgery (with HIFU – High Intensity Focused Ultrasound –, histotripsy devices and therapy monitoring tools). In this context, innovations in the ultrasound field always have enormous potential. In the history of ultrasound, many innovations have been developed since its establishment as a medical imaging device in the 1960s, roughly one or two per decade (Szabo, 2004). The key innovation that launched the modality in the 1960s, is the real time imaging capability through mechanical scanning. Multichannel systems with electronic control of transducer arrays were developed in the 1970s. In the 1980s, flow analysis tools came to maturity through color flow imaging and quantitative Doppler modes (Pulse Wave Doppler PWD). In the 1990's significant improvements in image quality were made possible with the introduction of real time compounding techniques and harmonic imaging. Although many of these concepts were studied in research laboratories years before the commercial dates cited above, it is systematically the maturity of a new technology that trigger the introduction of the innovations on commercially available platforms: for example, real time imaging was triggered by microprocessors development, Doppler modes were prompted by digital signal processing chips with enough dynamics to detect, at the same time, very weak blood signal and strong tissue echoes. The introduction of low cost Analog to Digital (A/D) converters has led to fully digital systems, significantly increasing the quality of the information delivered. Harmonic imaging was triggered by large bandwidth transducers, allowing reception of the signal at twice the transmit frequency. In the first decade of the 21st century, technology moved towards extensive miniaturization leading to the introduction of high performances portable devices. Portable devices have created new markets for ultrasound the emergency market for example, underlying again the disruptive potential of the modality. Today portable devices are the primary sources of

Modern Quality Assurance Requirements for Diagnostic Ultrasound Systems and Transducers

Physicians rely on the accuracy and quality of the clinical data derived from these ultrasound systems to make informed diagnosis. Consequently these systems must be periodically assessed by medical physicists, or other technically trained Hospital staff to insure they are operating according to factory specifications. A quantitative and objective electronic test device for diagnostic ultrasound systems, known as FirstAssist, has been evaluated as a tool that will provide assurance that the ultrasound unit is providing clinically efficacious data. FirstAssist ultrasound probe emulator and Philips iE33 cardiovascular ultrasound system. Probe emulator device is used to input signals into an ultrasound system to determine the functionality and performance of the ultrasound system in B-mode, Doppler and color flow imaging modes. The probe emulator can determine in the clinical setting that the ultrasound system is performing at a level expected. The FirstAssist is an important new tool that provides the physician with objective evidence that the ultrasound system they are using is providing the clinical data they expect from a fully functioning ultrasound system. FirstAssist also showed data that ultrasound systems in the field may not be functioning properly, but the physician was unaware that a problem existed. FirstAssist is a valuable and powerful new quality assurance tool for testing and ensuring the proper performance of ultrasound systems in the clinical setting.

Left Ventricular Assist Device-Related Systolic Aortic Regurgitation

A 39-year-old woman underwent transesophageal echocardiography during heart transplantation after 2.5 years of support with a continuous-flow left ventricular assist device (cf-LVAD). The patient was admitted to the hospital when a donor heart became available, and did not present with any symptoms or signs of heart failure on cf-LVAD support. Color-flow imaging demonstrated pronounced systolic aortic regurgitation (AR) while the LVAD was providing full support. The development of this unusual LVAD-related systolic AR may involve dynamic changes in resistance to flow of the aortic valve of an unknown mechanism. In most cases involving a combination of cf-LVAD support and aortic valve incompetence, AR would manifest as a mild-to-moderate diastolic or continuous valve regurgitation.1 Surprisingly, the patient demonstrated pronounced systolic AR (Figure 1 and Movie in the online-only Data Supplement) on support with a …

Estimation of blood velocity, volumetric flow and wall shear rate using Doppler ultrasound

Commercial ultrasound systems can make a number of measurements related to haemodynamics which are relevant to clinical practice and to clinical research. These include maximum velocity, volumetric flow and wall shear rate. Using appropriate protocols, measurements can be made averaged over the cardiac cycle, or as a function of time through the cardiac cycle. Maximum velocity underpins most of these measurements. Maximum velocity is overestimated as a result of geometric spectral broadening, by typically up to 30%, but by much larger amounts as the angle approaches 90°. Though not used in clinical practice, a simple correction technique using a string phantom can substantially reduce these errors. For volumetric flow and wall shear rate, methods such as specialist multi-gate ultrasound systems, magnetic resonance imaging and image guided modelling are available. Before resorting to these more complex methods users might consider that, with care and attention to procedure, high quality information may be obtained using commercial ultrasound systems. Manufacturers could make more use of the colour flow image for quantification of velocity, and adopt vector Doppler techniques.

Assessment of synovitis in the knee of patients with newly-diagnosed rheumatoid arthritis using high frequency and color Doppler ultrasonography

To investigate the value of high frequency and color Doppler ultrasonography in detection of synovitis and the intra-articular vascularization in the knee joint of patients with newly-diagnosed rheumatoid arthritis (RA). Forty-one patients (30 women, 11 men) with newly-diagnosed RA were recruited to a cross sectional study (RA group). Forty-one age and gender-matched healthy volunteers were used as control group. The thickness of hydatid fluid, synovium hyperplasia, color flow imaging, peak systolic velocity (PSV), end diastolic velocity (EDV), resistance index (RI), venous blood flow and intra-articular perfusion were evaluated by high frequency and color Doppler ultrasonography. Totally 91.46% knee joints with synovial hyperplasia (> 2 mm) were found in 41 patients with RA (75/82 knee joints), and the thickness of the synovial membrane was 2.2 - 19.7 mm (average 6.3 ± 3.4 mm). In aspect of blood flow, the percentage of 0 to 3 grade were 18.67% (14/75), 29.33% (22/75), 45.33% (34/75) and 6.67% (5/75), respectively; the results of arterial blood were indicated with PSV (10.82 ± 3.71 cm/s), EDV (3.86 ± 1.12 cm/s) and RI (0.61 ± 0.07), while the average of venous blood velocity was 2.72 ± 1.02 cm/s. Joint effusion was found in 69 joints (84.15%) with the anteroposterior diameter 2.4 - 16.1 mm (average 6.9 ± 3.2 mm). The thickness of synovial membrane was 1.2 - 1.8 mm (average 1.4 ± 0.4 mm) and no significant difference were observed in joint effusion, signal of blood flow and thickness of synovial membrane in the control group. High frequency and power Doppler ultrasonography may be a valuable and optimal clinical tool to accurately and objectively detect synovial hyperplasia, vascular pannus formation and joint effusion in the knee joint of patients with RA.

MO-F-220-02: Imaging Educational Course - Ultrasound Miniaturization

Ultrasound is used more often than any other medical imaging modality because compared to the alternatives it is fast, safe, portable, and inexpensive. Moreover ultrasound has evolved symbiotically with advances in integrated electronics to allow increasingly higher image quality, along with enhanced functional information, like color flow, perfusion, tissue-strain, and elasticity imaging. It has now become possible to incorporate in compact instruments capabilities that were only available in full size consoles a decade ago. Imagers consist of a sensor that both transmits and receives ultrasound, an electronic beamformer to create focused beams of energy, a mid processor to convert these into grey scale images or functional information, and a display module for output. User interface and control elements complete the units. Three key technologies drive ultrasound miniaturization. First, integrated electronics that allow more processing per volume and per watt are important for both the analog front end as well as the digital beamforming and mid processing units. Second, advances in CPU, and now GPUs, along with simpler software platforms allow many of the functions that used to be done in dedicated hardware to be done in software. Third, the migration of beamforming into the probe shrinks the cable diameter and distributes processing and power consumption. Several examples from recent progress will be used to illustrate these points: the introduction of laptop, tablet, and hand-held imagers; automatic image optimization to simplify the user experience, and automatic physiological parameter estimates. Recent studies show that in some cases the diagnostic utility of small ultrasound imagers matches results from the larger and more costly consoles. Ultrasound imaging will be adopted in more point-of-care and rural settings. Spurred by technological innovations, the ability of ultrasound to address quality, access, and cost issues will likely increase its utilization worldwide. Research supported by General Electric Corporation Learning Objectives: 1. Be able to describe the operation of the major parts of an ultrasound imager. 2. Appreciate recent advances in probes and microelectronics. 3. Understand how engineering specifications impact the diagnostic workflow.

Quantitation of Mitral Regurgitation

Mitral regurgitation (MR) is the most frequent valve disease. Nevertheless, evaluation of MR severity is difficult because standard color flow imaging is plagued by considerable pitfalls. Modern surgical indications in asymptomatic patients require precise assessment of MR severity. MR severity assessment is always comprehensive, utilizing all views and methods. Determining trivial/mild MR is usually easy, based on small jet and flow convergence. Specific signs of severe MR (pulmonary venous flow systolic reversal or severe mitral lesion) are useful but insensitive. Quantitative methods, quantitative Doppler (measuring stroke volumes) and flow convergence (aka PISA method), measure the lesion severity as effective regurgitant orifice (ERO) and volume overload as regurgitant volume (RVol). Interpretation of these numbers should be performed in context of specific MR type. In organic MR (intrinsic valve lesions) ERO ≥ 0.40 cm(2) and RVol ≥ 60 mL are associated with poor outcome, while in functional MR ERO ≥ 0.20 cm(2) and RVol ≥ 30 mL mark reduced survival. While MR assessment should always be comprehensive, quantitative assessment of MR provides measures that are strongly predictive of outcome and should be the preferred approach. The ERO and RVol measured by these methods require interpretation in causal context to best predict outcome and determine MR management.

Ultrasound color flow imaging based on compute unified device architecture

Ultrasound Color Flow Imaging(CFI) is widely used in clinical diagnosis.This paper made two improvements for previous research about Graphics Processing Unit(GPU) framework for CFI: on wall filtering block,the parallel regression filtering was implemented instead of Finite Impulse Response(FIR) filter;on post-processing block,the parallel threshold box filtering was added to improve flow uniformity.The experimental data were acquired from a healthy carotid artery: 88 scan lines,510 samples along the scan line,and an ensemble size of 16.The experimental results show that,compared with the serial algorithm based on Central Processing Unit(CPU),the computational efficiency of the proposed parallel algorithms based on GPU has been increased by 15.2 times and the frame rate increases up to 70.The color flow image can achieve a high quality by the regression filter instead of FIR filter,and improve the accuracy of tissue/flow detection by threshold box filter.

EVALUATION OF THE ALTERNATE BLOOD FLOW IN ESOPHAGEAL VARICEAL PATIENTS BY ENDOSCOPIC COLOR DOPPLER ULTRASONOGRAPHY

Background: Endoscopic color Doppler ultrasonography (ECDUS) is a useful modality for obtaining color flow images of esophageal varices. The direction of blood flow in passageways is fundamentally hepatofugal flow according to ECDUS. The present study is designed to evaluate the alternate direction of color flow image of passageways via ECDUS in esophageal variceal patients. Methods: The study involved 125 patients with esophageal varices using ECDUS. The grades of red color (RC) were as follows: RC(+) in 79 cases, RC(+ +) in 35 cases, and RC(+ + +) in 11 cases. We investigated the alternate direction on color flow images of the left gastric vein, the palisade vein, and the perforating veins via ECDUS. Results: Color flow images of the esophageal varices and the left gastric vein were obtained in all 125 (100%) patients by ECDUS. Color flow images of the perforating veins were obtained in 90 (72.0%) of the 125 patients. Vessel images of the palisade veins were detected in 33 (26.4%) of the 125 patients. The alternate direction on color flow images was detected in seven (5.6%) of the 125 patients with ECDUS: in three patients, left gastric vein; in three patients, perforating veins; and in one patients, left gastric vein and palisade veins. This phenomenon was observed periodically at regular intervals. The endoscopic findings were RC(+) in all seven patients. Conclusion: The alternate direction of blood flow in the passageways was observed in a few cases of RC(+) esophageal varices. We can observe the hemodynamics of esophageal varices non-invasively and in real time with ECDUS, and clarify the frequencies of the alternate direction of blood flow in RC-positive esophageal variceal patients.

Chest Ultrasound Helps to Diagnose Pulmonary Consolidations in Pediatric Patients

The diagnosis of pneumonia in pediatric patients relies on physical examination, blood tests, and chest X-rays. Physical examination, blood tests, and chest X-rays have a low accuracy, that is even greater in the critically ill. These limitations along with the risk of ionizing radiations, mandate the search for a safe diagnostic tool for patients with suspected pneumonia. Ultrasound (US) imaging offers several advantages over traditional radiographic techniques: it is non-invasive, painless, and involves minimal contact. In case of pulmonary parenchymal lesions, US is useful for differentiating pulmonary consolidation or atelectasis from lung masses and pleural lesions. Detection of air or fluid bronchograms at US and of pulmonary vessels with color flow imaging, is essential for the differential diagnosis of parenchymal consolidations. Furthermore US has a role in the evaluation of mediastinal masses and characterization of pleural fluid collection. Chest US is an ideal modality for serial examinations in rapidly evolving disease processes.