Ultrasound Coupling Gel Research Articles

Lymphatic Mapping with Contrast-enhanced Ultrasound for Lymphaticovenous Anastomosis Surgery: How We Do It.

Lymphaticovenous anastomosis (LVA) surgery is an effective surgery for the treatment of lymphedema in the extremities. Indocyanine green lymphography is the reference standard for visualizing lymphatics for LVA surgery, but it has several limitations; most notably, superficial dermal congestion can mask deeper lymphatic vessels. To overcome the limitations, we add contrast-enhanced ultrasound (CEUS) lymphography. We have previously reported that CEUS lymphography can identify lymphatic vessels for LVA surgery that indocyanine green lymphography does not. Here, we describe how we perform CEUS lymphography, including workflow, technique, and documentation. Before informed consent, the patient must be screened for possible adverse reactions to microbubbles. The procedure involves multiple intradermal injections of the microbubble agent at various sites along the extremity. After each injection, imaging for microbubble uptake by lymphatic vessels is performed using an ultrasound scanner with contrast-specific software. We use sulfur hexafluoride lipid-type A microspheres (Lumason/SonoVue; Bracco Suisse SA), but we are investigating the performance of other Food & Drug Administration-approved microbubble agents for CEUS lymphography. Having a systematic approach to marking the skin can mitigate the hindrance of marking over ultrasound coupling gel. Another benefit of CEUS lymphography is the rapid identification of neighboring veins compatible in size and location for anastomosis. We hold regular scheduled multidisciplinary meetings for coordination of care, discussion of outcomes, quality assurance, and ongoing innovation.

AIUM Practice Parameter for the Performance and Interpretation of Diagnostic Ultrasound of the Thyroid and Extracranial Head and Neck.

AIUM Practice Parameter for the Performance and Interpretation of Diagnostic Ultrasound of the Thyroid and Extracranial Head and Neck.

AIUM Official Statement: Guidelines for Cleaning and Preparing External- and Internal-Use Ultrasound Transducers and Equipment Between Patients as Well as Safe Handling and Use of Ultrasound Coupling Gel.

AIUM Official Statement: Guidelines for Cleaning and Preparing External- and Internal-Use Ultrasound Transducers and Equipment Between Patients as Well as Safe Handling and Use of Ultrasound Coupling Gel.

Factors Associated With Ultrasound Color Doppler Twinkling by Breast Biopsy Markers: In Vitro and Ex Vivo Evaluation of 35 Commercially Available Markers.

BACKGROUND. Targeted axillary lymph node dissection after neoadjuvant systemic therapy (NST) for breast cancer depends on identifying marked metastatic lymph nodes. However, ultrasound visualization of biopsy markers is challenging. OBJECTIVE. The purpose of our study was to identify biopsy markers that show actionable twinkling in cadaveric breast and to assess the association of actionable twinkling with markers' surface roughness. METHODS. Commercial breast biopsy markers were evaluated for twinkling artifact in various experimental conditions relating to scanning medium (solid gel phantom, ultrasound coupling gel, cadaveric breast), transducer (ML6-15, 9L, C1-6), and embedding material (present vs absent). Markers were assigned twinkling scores from 0 (confident in no twinkling) to 4 (confident in exuberant twinkling); a score of 3 or greater represented actionable twinkling (sufficient confidence to rely solely on twinkling for target localization). Markers were hierarchically advanced to evaluation with increasingly complex media if showing at least minimal twinkling for a given medium. A 3D coherence optical profiler measured marker surface roughness. Mixed-effects proportional odds regression models assessed associations between twinkling scores and transducer and embedding material; Wilcoxon rank sum test evaluated associations between actionable twinkling and surface roughness. RESULTS. Thirty-five markers (21 with embedding material) were evaluated. Ten markers without embedding material advanced to evaluation in cadaveric breast. Higher twinkling scores were associated with presence of embedding material (odds ratio [OR] = 5.05 in solid gel phantom, 9.84 in coupling gel) and transducer (using the C1-6 transducer as reference; 9L transducer: OR = 0.36, 0.83, and 0.04 in solid gel phantom, ultrasound coupling gel, and cadaveric breast; ML6-15 transducer: OR = 0.07, 0.18, and 0.00 respectively; post hoc p between 9L and ML6-15: p < .001, p = .02, and p = .04). In cadaveric breast, three markers (Cork, Professional Q, MRI [Flex]) exhibited actionable twinkling for two or more transducers; surface roughness was significantly higher for markers with than without actionable twinkling for C1-6 (median values: 0.97 vs 0.35, p = .02) and 9L (1.75 vs 0.36; p = .002) transducers. CONCLUSION. Certain breast biopsy markers exhibited actionable twinkling in cadaveric breast. Twinkling was observed with greater confidence for the C1-6 and 9L transducers than the ML6-15 transducer. Actionable twinkling was associated with higher marker surface roughness. CLINICAL IMPACT. Use of twinkling for marker detection could impact preoperative or intraoperative localization after NST.

The Value of First-Order Features Based on the Apparent Diffusion Coefficient Map in Evaluating the Therapeutic Effect of Low-Intensity Pulsed Ultrasound for Acute Traumatic Brain Injury With a Rat Model.

PurposeIn order to evaluate the neuroprotective effect of low-intensity pulsed ultrasound (LIPUS) for acute traumatic brain injury (TBI), we studied the potential of apparent diffusion coefficient (ADC) values and ADC-derived first-order features regarding this problem.MethodsForty-five male Sprague Dawley rats (sham group: 15, TBI group: 15, LIPUS treated: 15) were enrolled and underwent magnetic resonance imaging. Scanning layers were acquired using a multi-shot readout segmentation of long variable echo trains (RESOLVE) to decrease distortion. The ultrasound transducer was applied to the designated region in the injured cortical areas using a conical collimator and was filled with an ultrasound coupling gel. Regions of interest were manually delineated in the center of the damaged cortex on the diffusion weighted images (b = 800 s/mm2) layer by layer for the TBI and LIPUS treated groups using the open-source software ITK-SNAP. Before analysis and modeling, the features were normalized using a z-score method, and a logistic regression model with a backward filtering method was employed to perform the modeling. The entire process was completed using the R language.ResultsDuring the observation time, the ADC values ipsilateral to the trauma in the TBI and LIPUS groups increased rapidly up to 24 h. After statistical analysis, the 10th percentile, 90th percentile, mean, skewness, and uniformity demonstrated a significant difference among three groups. The receiver operating characteristic curve (ROC) analysis shows that the combined LR model exhibited the highest area under the curve value (AUC: 0.96).ConclusionThe combined LR model of first-order features based on the ADC map can acquire a higher diagnostic performance than each feature only in evaluating the neuroprotective effect of LIPUS for TBI. Models based on first-order features may have potential value in predicting the therapeutic effect of LIPUS in clinical practice in the future.

Disinfection of Ultrasound Transducers Using Non-Sterile Tissue Paper in Some Low-Cost Private Ultrasound Centres in Nigeria – Implications for Nosocomial Infection Management

Background/Aims: The incidence of disease outbreaks in clinical settings arising from ultrasound examinations is well documented, and is a source of worry. The ultrasound transducers and the coupling gel are potential sources of these infections since they come in direct contact with the patient’s skin. In this study, we examine the efficacy of the widespread practice of the use of plain non-sterile tissue paper in some low cost private ultrasound centres in our locality as a method of disinfecting ultrasound transducers after each use. Its potential impact on nosocomial infection management in clinical practice is also examined. Methods: Swab samples from convex ultrasound transducers before and after transabdominal scanning of three consecutive patients were obtained from 10 different ultrasound centres in urban and rural areas of Enugu state. Ultrasound coupling gel samples were equally obtained, and all samples cultured for bacteria growth which was quantified in colony forming units per ml (cfu/ml) and reported in 1000/ml. Paired sampled t-test was used to check for significance in reduction in bacterial load before and after the transducer was cleaned.Results: Nine different bacterial strains were isolated. Staphylococcus aureus and Klebsiella spp had the highest percentage of occurrence in all centres. Significant bacteria growth was recorded in the morning before the examination, and plain tissue paper significantly reduced the bacteria load in the ultrasound transducer.Conclusion: Even though disinfecting ultrasound transducers with non-sterile plain tissue paper alone is statistically effective and has the potential to minimize nosocomial infection, it is however not clinically effective and hence not advised.

The AIUM Practice Parameter for the Performance of an Ultrasound Examination of the Extracranial Cerebrovascular System.

The AIUM Practice Parameter for the Performance of an Ultrasound Examination of the Extracranial Cerebrovascular System.

The AIUM Practice Parameter for the Performance of an Ultrasound Examination of the Neonatal and Infant Spine.

The AIUM Practice Parameter for the Performance of an Ultrasound Examination of the Neonatal and Infant Spine.

The AIUM Practice Parameter for the Performance of an Ultrasound Examination of the Abdomen and/or Retroperitoneum.

The AIUM Practice Parameter for the Performance of an Ultrasound Examination of the Abdomen and/or Retroperitoneum.

Ultrasound-guided regional anesthesia in COVID-19 and future pandemics: infection control.

Purpose of reviewInfection control is inherent in ultrasound-guided regional anesthesia practice, because ultrasound transducer and coupling gel can be vectors for pathogen transmission. We reviewed the current standards and recommendations of ultrasound transducer cleaning, disinfection, and safe handling of ultrasound equipment. Based on the available data, we propose a set of practical recommendations applicable to coronavirus disease 2019 (COVID-19) pandemic and future epidemics.Recent findingsRegional anesthesia is often preferred over general anesthesia for COVID-19 patients. Avoidance of general anesthesia reduces the need for aerosol generating procedures. Administration of ultrasound-guided regional anesthesia and surgery under regional anesthesia in COVID-19 patients requires careful infectious precautions to prevent the viral spread through the use equipment.SummaryUltrasound machine, transducer and coupling gel can serve as a vector for transmission of pathogens. In the era of COVID-19 pandemic, standardized strategies are recommended to minimize the risk of spread of COVID-19 to both patients and the healthcare providers.

AIUM Practice Parameter for the Performance of Sonohysterography and Hysterosalpingo-Contrast Sonography.

AIUM Practice Parameter for the Performance of Sonohysterography and Hysterosalpingo-Contrast Sonography.

AIUM Practice Parameter for the Performance of Ultrasound Evaluations of the Prostate (and Surrounding Structures).

AIUM Practice Parameter for the Performance of Ultrasound Evaluations of the Prostate (and Surrounding Structures).

Disinfection of Ultrasound Transducers Used for Percutaneous Procedures: Intersocietal Position Statement.

Disinfection of Ultrasound Transducers Used for Percutaneous Procedures: Intersocietal Position Statement.

AIUM Practice Parameter for the Performance of an Ultrasound Examination of Solid-Organ Transplants.

AIUM Practice Parameter for the Performance of an Ultrasound Examination of Solid-Organ Transplants.

AIUM Practice Parameter for the Performance of Duplex Sonography of Native Renal Vessels

AIUM Practice Parameter for the Performance of Duplex Sonography of Native Renal Vessels

AIUM Practice Parameter for the Performance of Fetal Echocardiography.

AIUM Practice Parameter for the Performance of Fetal Echocardiography.

Systematic study of the effect of ultrasound gel on the performances of time-domain diffuse optics and diffuse correlation spectroscopy.

Recently, multimodal imaging has gained an increasing interest in medical applications thanks to the inherent combination of strengths of the different techniques. For example, diffuse optics is used to probe both the composition and the microstructure of highly diffusive media down to a depth of few centimeters, but its spatial resolution is intrinsically low. On the other hand, ultrasound imaging exhibits the higher spatial resolution of morphological imaging, but without providing solid constitutional information. Thus, the combination of diffuse optical imaging and ultrasound may improve the effectiveness of medical examinations, e.g. for screening or diagnosis of tumors. However, the presence of an ultrasound coupling gel between probe and tissue can impair diffuse optical measurements like diffuse optical spectroscopy and diffuse correlation spectroscopy, since it may provide a direct path for photons between source and detector. A systematic study on the effect of different ultrasound coupling fluids was performed on tissue-mimicking phantoms, confirming that a water-clear gel can produce detrimental effects on optical measurements when recovering absorption/reduced scattering coefficients from time-domain spectroscopy acquisitions as well as particle Brownian diffusion coefficient from diffuse correlation spectroscopy ones. On the other hand, we show the suitability for optical measurements of other types of diffusive fluids, also compatible with ultrasound imaging.

Bacterial contamination of ultrasound probes and coupling gels in a university hospital in Turkey

Objectives: Nosocomial outbreaks of infection originating from ultrasound probes and contaminated coupling gels have been reported. It was reported that the ultrasound probe, if cultured after routine scanning of intact skin, may become colonized with skin flora. Methods: Culture swabs from 22 probes of the 9 ultrasound machines and from the gels in the 10 gel folders were taken. All swabs taken from probe head, probe holder and the coupling gel in the folder at the beginning of the day were cultured. After fifth scanning and after wiping off the gel with a dry, nonsterile paper towel, cultures were again obtained from probe head and probe holder. Results: A total of 98 culture results were included of which 42.8% were positive for bacterial growth. The rate of bacterial contamination from probes at morning before the start of examination and after scanning were 34.1% and 56.8%, respectively and this difference was statistically significant (p = 0.023). Conclusions: We think that using nonsterile, dry, soft and absorbent paper towel after each procedure, could be inadequate for disinfection of probe head. Especially, good hand hygiene could decrease the rate of growth of bacterial colony at probe handle.

Shake No Bake: A Homemade Ultrasound Gel Recipe for Low-Resource Settings.

Commercially produced ultrasound coupling gel is often a scarce resource in rural regions of low-income countries that use sonography as their main imaging modality and, when available, may be cost prohibitive. Various homemade gels were created and tested to assure image quality was not compromised. Glucomannan-based gel and guar gum-based gel had superior physical properties in initial testing and showed no substantial difference compared with commercially available ultrasound gel on subject and phantom imaging and analysis (P > .05 using a 1-tailed sign test). Neither gel required heating, attracted insects, damaged ultrasound transducers, stained samples of clothing, or had harmful effects to subjects.

Microbubble oscillation induced acoustic micromixing in microfluidic device

Microfluidic is of great significance for biomedical research and chemical engineering. The mixing of liquids is an essential and necessary procedure for the sample preparation. Due to the low Reynolds number, laminar flow is dominant in a microfluidic channel and it is difficult to mix the fluids in the microchannel quickly and effectively. To improve the mixing efficiency of the liquids in microfluidic channels, we develop an acoustic mixer based on single microbubble oscillation. By designing the cylinder structure on the bottom surface, when the fluid flows through cylinder structure with a diameter of 40 m, the microbubble can be generated by the surface tension of the liquid. The device is fabricated by using standard soft lithography and the replica moulding technique, ensuring the stability and repeatability of the mixing. A piezoelectric transducer (PZT) with a resonant frequency of 165 kHz is attached to the polydimethylsiloxane microfluidic device on the glass substrate by ultrasound coupling gel. When the microbubble is excited by the PZT at a resonant frequency of 165 kHz, microbubble oscillates immediately. To verify whether ultrasound can induce microbubble cavitation, a passive cavitation detection system is established. The results show that the higher harmonics can be detected, indicating that the stable cavitation occurs. The microstreaming induced by the oscillating microbubble disturbs the fluid dramatically, achieving the mixture of liquids. Particle image velocimetry method is utilized to characterize the microstreaming, and a pair of counter-rotating vortices in the microchannel is detected. Furthermore, to test the performance of the device, the deionized water and rhodamine B are injected into the Y-shape microchannel. Relative mixing index is used to quantitatively analyze the mixing performance by measuring the grayscale values of the optical images. The results indicate that with the increase of the input power, mixing time can be shortened correspondingly. When the input power is 14.76 W, the mixing process is ultrafast, within 37.5 ms the high mixing uniformity can be achieved to be 92.7%. With the advantages of simple design, high efficient and ultrafast mixing, and low power consumption, this oscillating microbubble-based acoustic micromixer may provide a powerful tool for various biochemical studies and applications.