B-flow Sonography Research Articles

Comparison of B-Mode with B-Flow Sonography for the Evaluation of Femoral Arteries in Infants

Purpose To evaluate femoral arteries (FAs) in infants in the context of catheter angiography with B-mode (BMS) and B-flow sonography (BFS) and to compare both methods for vessel delineation and reliability of vessel diameter measurements. Methods 21 consecutive infants who underwent ultrasound for the evaluation of FAs before or after cardiac catheterization were retrospectively included in this study. The diameter of the FAs and the maximum length of the vessel section displayed on a single ultrasound plane were recorded by two radiologists for BMS and BFS. The visual image quality was rated by one observer. Statistics included intraclass correlation coefficient, Bland-Altman analysis, Fisher´s exact test and t-test. Results The intraobserver as well as interobserver correlation was excellent for BMS (0.7922 and 0.6521) and BFS (0.8094 and 0.7637). The Bland-Altman analysis revealed limits ofagreement for BMS between +/-0.73 mm (intraobserver)and +/-0.55 mm (interobserver) and for BFS between +/-0.83 mm (intraobserver) and +/-0.7 mm (interobserver).BFS allowed visualization of a longer stretch of the FAthanBMS (length 3.54 +/-0.85 vs. 2.21 +/-0.9 cm, p < 0.0001). The image quality was significantly higher forBFS (p = 0.0043). Conclusion Since BFS shows excellent reproducibility for vessel measurements and superior image quality in infants, ifavailable, BFS should be included in standard protocols when realistic measurements are required. Key Points · B-flow sonography offers high image quality for the evaluation of femoral arteries.. · Femoral artery diameter measurements performed with B-flow sonography show excellent reproducibility.. · If available, additional B-flow sonography of femoral arteries in infants is recommended.. Citation Format · Groth M, Dammann E, Arndt F et al. Comparison of B-Mode with B-Flow Sonography for the Evaluation of Femoral Arteries in Infants. Fortschr Röntgenstr 2017; 189: 1161 - 1167.

Novel Application of Four-Dimensional Sonography with B-Flow Imaging and Spatiotemporal Image Correlation in the Assessment of Fetal Congenital Heart Defects

To evaluate the role of four-dimensional (4D) ultrasound with B-flow imaging and spatiotemporal image correlation (STIC) in the evaluation of normal fetal heart and congenital heart disease during pregnancy. Volume data sets of the fetal heart were acquired with automated transverse and longitudinal sweeps of the anterior chest wall. We studied 31 normal fetuses and 28 fetuses with congenital heart disease (6 with double-outlet right ventricle, 5 with complete transposition of great arteries, 8 with tetralogy of Fallot, 3 with right aortic arch, 2 with persistent left superior vena cava, 3 with truncus arteriosus communis, and 1 with interruption of aortic arch) at gestation ages ranging from 18 to 39 weeks using transabdominal 4D B-flow sonography with STIC (4D BF-STIC). Four-dimensional BF-STIC demonstrated dynamic angiographic features in both normal and abnormal fetal hearts. Four-dimensional BF-STIC images could not be obtained in two normal fetuses at 18.9 and 35.6 weeks because of the high fetal heart rate and inappropriate fetal position. Of the other 29 fetuses all extracardiac vessels such as aorta, pulmonary artery, ductus arteriosus, inferior vena cava, and ductus venosus could be detected on reconstructed images. In seven normal cases, a 4D image was recorded to allow simultaneous visualization of all four pulmonary veins. In the 28 fetuses with cardiac anomalies, 4D sonography with B-flow imaging and STIC detected the "digital casts" of the outflow tracts, great arteries, and veins draining into the heart. These results demonstrate spatial relationship among these structures which provide important anatomical information. Four-dimensional BF-STIC provides a means of real time three-dimensional evaluation of fetal extracardiac hemodynamics in the second and third trimesters. This novel technique assists in the evaluation of fetal cardiac hemodynamics and may play an important role in future fetal cardiac research and in the identification of anatomical features of different congenital cardiac anomalies.

B-flow and color Doppler sonography findings in iatrogenic carotid–jugular arteriovenous fistula

We describe the case of a 66-year-old woman with an aortic valve reconstruction. Subsequently she presented with an arteriovenous fistula (AVF) between the left common carotid artery and internal jugular vein following several attempts of jugular catheter insertion. Due to aliasing, correct visualization of the fistula track was hindered by conventional color Doppler. However, by using the B-flow imaging technique, the fistula track could be detected without aliasing or overwriting. Duplex examination revealed an AVF between both vessels with an arterialized waveform in the left jugular vein and a high-velocity turbulent flow inside the fistula. Due to these findings we will change our routine scanning protocol for extracranial vessels and will use B-flow in indistinctive or difficult conditions to obtain additional informations.

Four‐dimensional sonography with B‐flow imaging and spatiotemporal image correlation for visualization of the fetal heart

To use B-flow imaging with 4-dimensional (4D) sonography and spatiotemporal image correlation (STIC) in the evaluation of normal fetal heart and congenital heart disease during pregnancy. Volume data sets of the fetal heart were acquired with automated transverse and longitudinal sweeps of the anterior chest wall. We studied 13 normal fetuses and 2 fetuses with congenital heart disease (1 double-outlet right ventricle and 1 hypoplastic left heart syndrome) at gestation ages ranging from 13 to 39 weeks using transabdominal 4D B-flow sonography with STIC (4D BF-STIC). 4D BF-STIC demonstrated dynamic angiographic features in both normal and abnormal fetal hearts. 4D BF-STIC images could not be obtained in 2 normal fetuses at 18.1 and 33.1 weeks because of the high fetal heart rate and inappropriate fetal position. In normal fetal heart, characteristic hemodynamic changes in both atria and ventricles were clearly demonstrated in systole and diastole. 4D BF-STIC also allowed visualization of the relationship, size, and course of the outflow tracts, thus helping the examiner to better understand the relationships between the vessels. In a case of hypoplastic left heart syndrome, dramatic hemodynamic changes including the right atrium, right ventricle, and pulmonary artery were evident. In a case of double-outlet right ventricle with ventricular septal defect, left-to-right shunt flow through a ventricular septal defect was clearly shown, as were great arteries originating in parallel from the right ventricle. 4D BF-STIC provides a means of real-time 3-dimensional evaluation of fetal intracardiac and extracardiac hemodynamics in the second and third trimesters. This novel technique assists in the evaluation of fetal cardiac hemodynamics and may play an important role in future fetal cardiac research and in the evaluation of congenital heart disease in the fetus.

B-Flow Sonography for Detecting Portal Venous Stenosis After Liver Transplantation

A case of a patient in his early 60s with a portal vein stenosis after liver transplantation (LTx) detected by sonography in B-flow mode is reported. Two weeks after LTx, the patient developed ascites and severe alteration of liver function tests. Color Doppler (CD) demonstrated a stenosis in the portal vein with a maximum flow of 340 cm/sec. Due to aliasing, correct assessment of stenosis diameter was not possible by means of CD. However, by using the B-flow imaging technique, slow and fast velocities in the pre-, intra-, and poststenotic segment could be detected without aliasing or overwriting. In addition, a second stenosis in the portal vein was identified. For the follow-up outcome of patients, it is essential to detect and treat this complication. After surgical intervention, graft function recovered and postoperative flow measurements showed a normal portal vein flow of 70 cm/sec in the poststenotic segment.

B‐flow sonographic demonstration for assessing carotid atherosclerosis in young patients with heterozygous familial hypercholesterolemia

To determine whether bloodstream swirls detected with B-mode flow (B-flow) sonography at the region of the carotid bifurcation can predict the early progression of atherosclerosis, we prospectively examined the relationships between the size of bloodstream swirls as identified with B-flow sonography, the local mechanical behavior of the common carotid artery (CCA), and some cardiovascular risk factors in young patients with heterozygous familial hypercholesterolemia (FH). Thirty-eight young patients (mean age 25.8 +/- 14.1 years) with FH were evaluated for the following parameters: age, sex, body mass index, degree of dyslipidemia, presence of a plaque, intima-media thickness (IMT), elastic modulus (Ep) and internal diameter of the CCA via duplex scan, wall shear stress, maximal diameter of the bloodstream swirl (Sm) at bifurcation, maximal diameter of the CCA (Cm) at the level of the swirl's center, and diameter ratio (Sm/Cm) via B-flow sonography. Bloodstream swirls of varying size at the site of bifurcation were observed in all patients. Six (15.7%) out of 38 patients exhibited plaques at bifurcation. All plaques were located at the far wall and were in contact with the distal portion of the bloodstream swirl as observed with B-flow sonography. Univariate analysis revealed that Sm/Cm and Sm were positively correlated with age, presence of a plaque, IMT, and Ep and were negatively correlated with shear stress. Multivariate analysis revealed that Sm was significantly correlated with age (P < 0.01) and Ep (P < 0.05). Our results suggest that a bloodstream swirl visualized at the carotid bifurcation with B-flow sonography may be an indicator of a local mechanism for the age-related progression of atherosclerosis in young patients with FH.

B-Flow Sonographic Evaluation of Hemodialysis Fistulas

The purpose of this study was to determine the effectiveness of B-flow sonography in the evaluation of hemodialysis fistulas and to compare this new technique with color and power Doppler sonography. In this study, 32 randomly selected patients (mean age, 46 years; age range, 18-87 years) with normally functioning hemodialysis fistulas were evaluated with low- and high-pulse repetition frequency (PRF) color and power Doppler sonography (PRF values of 3 and 10 kHz) and B-flow sonography. All images were reviewed and graded independently by 2 observers for luminal filling with flow signals, visibility of the intimal layer, and overall image quality. The study was approved by the Institutional Review Board, and informed consent was obtained from all patients. Statistical analysis with Friedman and Wilcoxon signed rank tests revealed that B-flow sonography was superior to other techniques for luminal filling and visibility of the intimal layer (P = .000). For overall image quality, B-flow sonography was also the best method according to the Friedman test (P = .000). However, the Wilcoxon test showed no significant difference between B-flow and high-PRF (10-kHz) color and power Doppler sonography (P = .131). The kappa scores reflected moderate to good interobserver agreement (kappa = 0.285-0.784). B-flow sonography is a relatively new and superior imaging technique that provides direct visualization of the blood echoes and the morphologic characteristics of the surrounding vessel wall simultaneously. During the evaluation of hemodialysis shunts, the major advantage of this technique is its ability to avoid artifacts such as aliasing and overwriting.

New fetal cardiac imaging techniques

Rapid advances in graphics computing and micro-engineering have offered new techniques for prenatal cardiac imaging. Some of them can be non-invasively applied to both clinical and laboratory settings, including dynamic three-dimensional echocardiography, myocardial Doppler imaging, harmonic ultrasound imaging, and B-flow sonography. With clinical constraints, a few others have been mainly used in laboratories, such as endoscopic ultrasound, magnetic resonance imaging and biomicroscopy. Appropriate use and co-use of these new tools will not only provide unique information for better clinical assessment of fetal cardiac disease but also offer new ways to improved understanding of cardiovascular development and pathogenesis.