High Frequency Ultrasound System Research Articles

Abstract 12894: Murine Arterial Wall Strain Estimation With Ultrasound-Based Lagrangian Carotid Strain Imaging and Validation Against Histological Findings

Introduction: Early identification of arterial injury by non-invasive imaging can facilitate research into mechanisms of arterial injury and has the potential to improve patient management. We tested the hypothesis that Lagrangian carotid strain imaging (LCSI) combined with adaptive Bayesian regularization could detect early arterial injury and monitor atherogenesis in a murine model by associating findings with histological examinations. Methods: Radio-frequency (RF) data were collected from the right and left common carotid arteries (CCA) of 10 (5 male and 5 female) ApoE tm1Unc/J mice at 6, 16 and 24 weeks using a high frequency ultrasound system. Cumulative axial, lateral and shear strain images were estimated using LCSI and 3 strain indices: maximum accumulated strain index (MASI), peak mean strain of full ROI index (PMSRI) and strain at peak axial displacement index (SPADI). Mice were euthanized (n=2 at 6 and 16 weeks, n=6 at 24 weeks) for histological examination. Results: We observed sex-specific differences in the temporal variation of strain indices. For male mice, axial PMSRI and SPADI changed significantly from 6 to 24 weeks (mean axial SPADI at 6 = 14.10±6.30 % and 24 weeks = 0.24±6.22%; p=0.0004). For female mice, lateral MASI was significantly higher at 24 than 6 weeks (mean lateral MASI at 6 = 10.26±3.13 % and 24 weeks = 16.42±7.15% p=0.048). Both sexes had strong associations with histological findings. For males, axial PMSRI and SPADI showed significant correlation with the number of elastin fibers (axial PMSRI: r s =0.83, p=0.01; axial SPADI: r s =0.76, p=0.02). For females, lateral and shear MASI had significant correlations with plaque scores (lateral MASI: r s =0.66, p=0.04; shear MASI: r s 0.77, p =0.009). Conclusions: LCSI can quantify carotid arterial wall strain in a murine model non-invasively. Changes in strain were associated with changes in arterial wall microstructure after plaque formation.

Abstract LBA051: Importance of drug osmotic pressure and viscosity for efficient drug delivery using lymphatic drug delivery system

Abstract Metastasis is known to be the prime cause of cancer associated fatality. It is therefore imperative to treat and prevent metastasis in order to curb cancer-associated morbidity and mortality. Metastatic lymph nodes (MLNs) are known to be crucial diagnostic and prognostic indicators. Furthermore, as per the lymph node mediated hematogenous theory, due to extant communication between the lymphatic network and the venous system, the lymphatic network facilitates the passage and subsequent colonization of tumor cells to distant sites, thus, serving as a starting point for distant metastasis even during the initial stages. Treatment of MLNs, therefore, is imperative. Proposed in 2015, the Lymphatic Drug Delivery System (LDDS) is a novel and promising drug delivery system for the treatment of MLNs that overcomes the limitations of conventional chemotherapy. Unlike systemic chemotherapy, LDDS entails a direct intranodal drug administration to sentinel lymph node, post its identification using radioisotopes and fluorescent molecules, in order to treat it and its downstream lymph nodes. Previous studies have documented the superior efficacy of LDDS as a MLN management strategy as compared to conventional therapy. Higher drug delivery to target sites and prolonged retention with lower systemic toxicity, and thereby stronger anti-tumor effect have been reported to have been achieved upon drug administration via LDDS. In the present study, MXH10/Mo/lpr mice and FM3A-Luc, mouse mammary carcinoma cells expressing the firefly luciferase gene, have been utilized for the establishment of a mouse model of Lymph node metastasis (LNM) to investigate the effect of drug osmotic pressure and viscosity on therapeutic efficacy of the LDDS. Two lymph nodes, exhibiting systemic lymphadenopathy, in the subiliac and axillary region, the subiliac lymph node (SiLN) and proper axillary lymph node (PALN) have been used to model a network of interconnected human lymph nodes. Drug solution of varying osmotic pressure and viscosity were administered via LDDS to the murine model of LNM and subsequently therapeutic efficacy was monitored using the high frequency ultrasound system, VEVO and bioluminescent imaging system, IVIS, and confirmed through histology. The study revealed an optimized window of drug osmotic pressure and viscosity (π = 1000 - 2000 kPa; µ = 0.9 - 11.5 mPa·s.) where a significantly stronger anti-tumor response was observed. Venturing below or beyond the optimized range results in decreased therapeutic efficacy. The study therefore concluded that drug osmotic pressure and viscosity are important fluid parameters that require careful consideration prior to preparation of drug cocktails as they can severely impact the prognosis. The findings of this study have the potential for translation to clinics and we anticipate that these results can be replicated in clinical trials, positively altering the fate of many cancer patients. Citation Format: Radhika Mishra, Ariunbuyan Sukhbaatar, Sora Shouta, Maya Sakamoto, Shiro Mori, Tetsuya Kodama. Importance of drug osmotic pressure and viscosity for efficient drug delivery using lymphatic drug delivery system [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr LBA051.

Tissue factor cytoplasmic tail regulates myeloid cell derived superoxide formation and TGF-beta 1 driven cardiac remodeling in myocardial infarction

Abstract Background In the setting of myocardial infarction (MI), patients with coronary no-reflow and/or delayed presentation after onset of symptoms (sub-acute MI) are inflicted by severe thrombo-inflammation and are marked by worse clinical outcome. However, it is unclear whether tissue factor (TF) contributes to outcome post MI solely by the regulatory functions of its cytoplasmic tail independently of its coagulation activity. Purpose We analyzed the role of the TF cytoplasmic domain in the recruitment of myeloid cells into the infarcted myocardium and the consequences on cardiac remodeling, scar formation, development of heart failure and survival post MI. Methods Twelve Patients enrolled in the MICAT (Mainzer Intracoronary Database, ClinicalTrials.gov Identifier: NCT02180178) study were examined. Patients with sub-acute MI and stable coronary artery disease were defined and monocytes were isolated from peripheral blood mononuclear cells (PBMCs). Human heart samples acquired from the left ventricular wall of explanted hearts following cardiac transplantation or obtained during implantation of left ventricular assist device. Samples were investigated for downstream analysis of protein by western blots, RNA quantification and cryo-sectioning. MI was induced in 9 to 12 weeks old male C57BL/6J mice, mice specifically lacking the cytoplasmic tail (CT) of TF (TFΔCT mice) and TFfl/flLysMCre+/− mice by permanent ligation of the left anterior descending artery. Left ventricular function was assessed by High-Frequency Ultrasound System. Infiltration of immune cells into the infarcted myocardium was analyzed by performing flow cytometric analysis after enzymatic digestion of the myocardium. Superoxide levels were quantified by HPLC-based measurement of dihydroethidium derived oxidation product 2-hydroxy ethidium. Results Circulating monocytes in patients with sub-acute MI showed increased nitrosative stress as well as increased phosphorylation of TF CT along with TGF-β1 and NF-kB inflammatory activation, which was recapitulated in cardiac tissue of end-stage heart failure patients with chronic MI. MI results in phosphorylation of the CT of TF within myeloid cells. Using mice with conditional knockout of TF on myeloid cells or TFΔCT mice, we found that this regulatory intracellular domain of TF within myeloid cells is required for cardiac infiltration of inflammatory Ly6Chigh TF+ monocytes, Rac-1 GTPase and superoxide formation of gp91phox + myeloid cells in MI. TGF-β1 dependent SMAD2 activation and cardiac collagen deposition as late sequel of MI was reduced in TFΔCT mice, resulting in attenuated cardiac dysfunction and reduced mortality. Conclusion We conclude that, TF CT drives NADPH-oxidase derived superoxide formation, thrombo-inflammation and cardiac fibrosis. Therefore, it might serve as putative biomarker and risk predictor in MI Funding Acknowledgement Type of funding source: None

A Preliminary Study for Quantitative Assessment with HFUS (High- Frequency Ultrasound) of Nodular Skin Melanoma Breslow Thickness in Adults Before Surgery: Interdisciplinary Team Experience.

Cutaneous melanoma is one of the most severe skin diseases. Nodular melanoma is the second melanoma subtype in order of frequency. The prognosis of skin melanoma depends on the vertical growth of the tumor (Breslow index). For this measurement, excisional biopsy is strongly recommended. This is, however, an invasive procedure and may cause damage to the lymphatic drainage system. The HFUS system, , can be extremely useful for determining tumor thickness in the preoperative phase, given its high resolution capacity. The aim of this preliminary study is to define the role of HFUS for the nodular skin melanoma Breslow thickness in adults before surgery by making a comparison with histological features. In this study, 14 melanocytic lesions (8 male and 6 female) were evaluated with dermatoscopic clinical features strongly indicative of nodular melanoma. Out of these, excisional biopsy of 7 lesions was requested. The ultrasounds were performed preoperatively. The images were acquired through the first ultrasound scanner with ultra-high frequency probes (range from 50MHz to 70 MHz) available on the market under the EEC mark (Vevo "MD, FUJIFILM Visual Sonics, Amsterdam, the Netherlands) equipped with a linear probe of 50-70 MHz. From the ultrasonographic analysis of 14 nodular melanoma thickness was determined for the presence of two hyperechogenic laminae, separated by a hypo / anechoic space. The twelve lesions were in situ while the other two lesions showed ultrasonography for example; the satellite lesions (less than two centimeters from the primary lesion) and in transit (localizable to more than two centimeters from the primary lesion). Four of these lesions were ulcerated. A comparsion was made the 7 lesions on between the thickness calculated with this method, and that obtained on the bioptic piece. The presence of a positive concordance has been evident in all of the cases. If further studies are needed to support its widespread clinical use, its is believed that, in expert hands and with an interdisciplinary team, HFUS is already capable to reliably calculate a Breslow index in a large majority of patients with cutaneous melanoma.

Oxidative degradation of phenols in sono-Fenton-like systems upon high-frequency ultrasound irradiation

The kinetics of oxidative degradation of phenol and chlorophenols upon acoustic cavitation in the megahertz range (1.7 MHz) is studied experimentally in model systems, and the involvement of in situ generated reactive oxygen species (ROSs) is demonstrated. The phenols subjected to high frequency ultrasound (HFUS) are ranked in terms of their rate of conversion: 2,4,6-trichlorophenol > 2,4-dichlorophenol ~ 2-chlorophenol > 4-chlorophenol ~ phenol. Oxidative degradation upon HFUS irradiation is most efficient at low concentrations of pollutants, due to the low steady-state concentrations of the in situ generated ROSs. A dramatic increase is observed in the efficiency of oxidation in several sonochemical oxidative systems (HFUS in combination with other chemical oxidative factors). The system with added Fe2+ (a sono-Fenton system) derives its efficiency from hydrogen peroxide generated in situ as a result of the recombination of OH radicals. The S2O82-/Fe2+/HFUS system has a synergetic effect on substrate oxidation that is attributed to a radical chain mechanism. In terms of the oxidation rates, degrees of conversion, and specific energy efficiencies of 4-chlorophenol oxidation based on the amount of oxidized substance per unit of expended energy the considered sonochemical oxidative systems form the series HFUS < S2O82-/HFUS < S2O82-/Fe2+/HFUS.

X-linked dominant protoporphyria: report of a pedigree and detection of ALAS2 gene mutations

Objective To report a pedigree with X-linked dominant protoporphyria (XLDPP), and to detect 5-aminolevulinic acid synthetase 2 (ALAS2) gene mutations in this pedigree. Methods A clinical investigation was performed in a pedigree with XLDPP, and relevant data were collected from family members. A next-generation sequencing method was applied to screen possible mutation sites, and Sanger sequencing was performed to determine pathogenic gene mutations. Dermoscopy was conducted to observe skin lesions in the patients with XLDPP, and the Fotofinder system and very high frequency (VHF) ultrasound system were utilized to assess the severity of photodamage. Liver and gallbladder ultrasonography as well as blood examination were performed for all the family members. Results A deletion mutation, c.1706-1709 ΔAGTG, was detected in the ALAS2 gene on the X chromosomes of all the patients in this family, which led to replacement or loss of 19-20 C-terminal residues through transcriptional frameshifting, and eventually caused an increase in ALAS2 activity. In the patients with XLDPP, skin photodamage was relatively severe; protoporphyrin-induced hepatobiliary damage was observed and aggravated with age; anemia and iron deficiency occurred sometimes. Conclusion The deletion mutation c.1706-1709 ΔAGTG of the ALAS2 gene may be the underlying cause of XLDPP in this pedigree. Key words: Porphyria, erythropoietic; Genetic diseases, X-linked; DNA mutational analysis; 5-Aminolevulinic acid synthetase 2 gene; Photoaging

Mapping 3D Strains with Ultrasound Speckle Tracking: Method Validation and Initial Results in Porcine Scleral Inflation.

This study aimed to develop and validate a high frequency ultrasound method for measuring distributive, 3D strains in the sclera during elevations of intraocular pressure. A 3D cross-correlation based speckle-tracking algorithm was implemented to compute the 3D displacement vector and strain tensor at each tracking point. Simulated ultrasound radiofrequency data from a sclera-like structure at undeformed and deformed states with known strains were used to evaluate the accuracy and signal-to-noise ratio (SNR) of strain estimation. An experimental high frequency ultrasound (55MHz) system was built to acquire 3D scans of porcine eyes inflated from 15 to 17 and then 19mmHg. Simulations confirmed good strain estimation accuracy and SNR (e.g., the axial strains had less than 4.5% error with SNRs greater than 16.5 for strains from 0.005 to 0.05). Experimental data in porcine eyes showed increasing tensile, compressive, and shear strains in the posterior sclera during inflation, with a volume ratio close to one suggesting near-incompressibility. This study established the feasibility of using high frequency ultrasound speckle tracking for measuring 3D tissue strains and its potential to characterize physiological deformations in the posterior eye.

PO-0022 Assessment Of Coronary Artery In A Murine Model Of Kawasaki Disease By Echocardiography

Introduction This study sought to assess the changes of coronary artery complications and cardiac function in the murine model of Kawasaki disease (KD) with a high frequency ultrasound system. Methods Lactobacillus casei cell wall extract (LCWE) was prepared, and injected to C57BL/6 mice intraperitoneally to induce KD. Totally 40 mice were categorised into KD model group and the control group randomly. On days 10, 21 and 60, coronary artery were measured by echocardiography. Left ventricular end-diastolic diameter (LVIDd), end-systolic diameter (LVIDs), ejection fraction (EF), fractional shortening (FS) and blood flow velocity of atrio-ventricular valve during early diastole (E)/atrial contraction (A) were also assessed. Results Echocardiography detected coronary artery and measured cardiac function in all mice. There was a high density echo images around the coronary artery wall at 10 days and 21 days in the KD group, 4(20%) presented local coronary artery aneurysm at 14 days and 21 days. The diameter of left coronary artery in KD group (0.46 ± 0.11 mm on D10, 0.47 ± 0.09 mm on D21) was larger than controls (0.32 ± 0.14 mm on D 10, 0.36 ± 0.06 mm on D21, all p Conclusions Coronary artery and cardiac function could be assessed easily by echocardiography in murine model of KD. Murine model of KD established by LCWE was shown similar natural progression on coronary artery abnormalities with KD patient.

Transplantation of pulmonary valve using a mouse model of heterotopic heart transplantation.

Tissue engineered heart valves, especially decellularized valves, are starting to gain momentum in clinical use of reconstructive surgery with mixed results. However, the cellular and molecular mechanisms of the neotissue development, valve thickening, and stenosis development are not researched extensively. To answer the above questions, we developed a murine heterotopic heart valve transplantation model. A heart valve was harvested from a valve donor mouse and transplanted to a heart donor mouse. The heart with a new valve was transplanted heterotopically to a recipient mouse. The transplanted heart showed its own heartbeat, independent of the recipient's heartbeat. The blood flow was quantified using a high frequency ultrasound system with a pulsed wave Doppler. The flow through the implanted pulmonary valve showed forward flow with minimal regurgitation and the peak flow was close to 100 mm/sec. This murine model of heart valve transplantation is highly versatile, so it can be modified and adapted to provide different hemodynamic environments and/or can be used with various transgenic mice to study neotissue development in a tissue engineered heart valve.

AB0783 Dermal thickness, peripheral blood perfusion and nailfold microangiopathy in systemic sclerosis patients

BackgroundIncreased dermal thickness (DT), decreased peripheral blood perfusion (PBP), and nailfold microangiopathy are typical clinical aspects of systemic sclerosis (SSc) (1-3).ObjectivesTo investigate possible correlations between DT and both PBP degree...

The Mechanical Properties of Ex Vivo Bovine and Porcine Crystalline Lenses: Age-Related Changes and Location-Dependent Variations

The mechanical properties of ex vivo animal lenses from three groups were evaluated: old bovine (25–30 mo old, n = 4), young bovine (6 mo old, n = 4) and young porcine (6 mo old, n = 4) eye globes. We measured the dynamics of laser-induced microbubbles created at different locations within the crystalline lenses. An impulsive acoustic radiation force was applied to the microbubble, and the microbubble displacements were measured using a custom-built high pulse repetition frequency ultrasound system. Based on the measured dynamics of the microbubbles, Young's moduli of bovine and porcine lens tissue in the vicinity of the microbubbles were reconstructed. Age-related changes and location-dependent variations in the Young's modulus of the lenses were observed. Near the center, the old bovine lenses had a Young's modulus approximately fivefold higher than that of young bovine and porcine lenses. The gradient of Young's modulus with respect to radial distance was observed in the lenses from three groups.

Development of a Bipolar Pulse Generator for High-Frequency Ultrasound Imaging System

The pulse generator is the critical component in high-frequency ultrasound imaging systems. Currently, there still exist some shortcomings about commercial ultrasound image systems and devices such as 5900 PR …etc.. However, to achieve a higher sensitivity and high performance, a programmable pulser generator is desired to match the requirements of high frequency ultrasound image system. In this study, we utilized a novel bipolar pulse generator method to overcome those issues in developed high resolution image system. As the needs of application in clinic, a real –time of high-frequency ultrasound imaging systems, including pulse generator, high speed scanning mechanism, high voltage protection and FPGA trigger control circuit, was developed in our Laboratory. This paper will focus to compare the performance of the bipolar generator and unipolar generator as used in pulse generator device respectively. Finally, the developed bipolar pulse generator show the better performance than the unipolar generator does. The bipolar system can generate clean N-cycle bipolar pulses and improve the center frequency of transducer up to 60 MHz. The axial resolution of scan system has been improved to around 60 μm. In addition, the result indicated that the proposed bipolar pulser could increase 4 dB for pulse/echo waveforms amplitude.

A high pulse repetition frequency ultrasound system for the ex vivo measurement of mechanical properties of crystalline lenses with laser-induced microbubbles interrogated by acoustic radiation force

A high pulse repetition frequency ultrasound system for an ex vivo measurement of mechanical properties of an animal crystalline lens was developed and validated. We measured the bulk displacement of laser-induced microbubbles created at different positions within the lens using nanosecond laser pulses. An impulsive acoustic radiation force was applied to the microbubble, and spatio-temporal measurements of the microbubble displacement were assessed using a custom-made high pulse repetition frequency ultrasound system consisting of two 25 MHz focused ultrasound transducers. One of these transducers was used to emit a train of ultrasound pulses and another transducer was used to receive the ultrasound echoes reflected from the microbubble. The developed system was operating at 1 MHz pulse repetition frequency. Based on the measured motion of the microbubble, Young’s moduli of surrounding tissue were reconstructed and the values were compared with those measured using the indentation test. Measured values of Young’s moduli of four bovine lenses ranged from 2.6 ± 0.1 to 26 ± 1.4 kPa, and there was good agreement between the two methods. Therefore, our studies, utilizing the high pulse repetition frequency ultrasound system, suggest that the developed approach can be used to assess the mechanical properties of ex vivo crystalline lenses. Furthermore, the potential of the presented approach for in vivo measurements is discussed.

Application of optical coherence tomography and high-frequency ultrasound imaging during noninvasive laser vasectomy

A noninvasive approach to vasectomy may eliminate male fear of complications related to surgery and increase its acceptance. Noninvasive laser thermal occlusion of the canine vas deferens has recently been reported. Optical coherence tomography (OCT) and high-frequency ultrasound (HFUS) are compared for monitoring laser thermal coagulation of the vas in an acute canine model. Bilateral noninvasive laser coagulation of the vas was performed in six dogs (n=12 vasa) using a Ytterbium fiber laser wavelength of 1075 nm, incident power of 9.0 W, pulse duration of 500 ms, pulse rate of 1 Hz, and 3-mm-diameter spot. Cryogen spray cooling was used to prevent skin burns during the procedure. An OCT system with endoscopic probe and a HFUS system with 20-MHz transducer were used to image the vas immediately before and after the procedure. Vasa were then excised and processed for gross and histologic analysis for comparison with OCT and HFUS images. OCT provided high-resolution, superficial imaging of the compressed vas within the vas ring clamp, while HFUS provided deeper imaging of the vas held manually in the scrotal fold. Both OCT and high HFUS are promising imaging modalities for real-time confirmation of vas occlusion during noninvasive laser vasectomy.

In vivo monitoring of venous thrombosis in mice

Venous thrombosis (VT) is an important cause of morbidity and mortality in clinical medicine. Animal models studying venous thrombosis are scarce and, in most cases, very crude and rely on sacrificing the animals to excise formed thrombi. Developing an in vivo murine model of venous thrombosis can be a powerful tool for studying venous thrombosis. We sought to use a high-frequency ultrasound system (HFUS) to dynamically and non-invasively monitor thrombus formation in the inferior vena cava (IVC) of mice. We developed a murine model of venous thrombosis using, for detection, the Vevo 770(®), a micro-imaging HFUS. Two different thrombosis models were used to generate thrombi in the IVC of C57Bl/6NCr mice: (i) ligation and (ii) application of ferric chloride (FeCl(3)). We then assessed venous thrombosis by HFUS. In both models, measurements of the clot pathologically correlated favorably with measurements acquired with HFUS. Thrombus develops less than an hour after ligation or FeCl(3) -induced injury of the IVC and the size of the clot increases over time for up to 24 h. Importantly, we demonstrate that HFUS can be used to monitor the effect of an anticoagulant such as dalteparin until complete resolution of the thrombus. These data show that HFUS assesses venous thrombosis in mice reliably and non-invasively. Developing a murine model of thrombosis using more accurate, and clinically more relevant, techniques such as ultrasonography, is a step towards a better understanding of the pathophysiology of venous thromboembolism.

Volumetric and Angiogenic Evaluation of Antitumor Effects with Acoustic Liposome and High-Frequency Ultrasound

Acoustic liposomes (AL) have their inherent echogenicity and can add functionality in serving as drug carriers with tissue specificity. Nonuniform vascular structures and vascular branches/bends are evaluated by imaging the intravascular movement locus of ALs with high-frequency ultrasound (HF-US) imaging. However, the evaluation of antitumor effects on angiogenesis by ALs and HF-US imaging has not been reported. Here, we show that the combination of ALs and an HF-US imaging system is capable of noninvasively evaluating antitumor volumetric and angiogenic effects in preclinical mouse models of various cancers. In this study, the antitumor effects of cisplatin on tumor growth and angiogenesis in mice bearing two different types of tumor cells were assessed. By tracking each AL flowing in the vessel and transferring the images to personal computers, microvessel structures were mapped and reconstructed using the color difference based on SD method. The antitumor effects were confirmed with an in vivo bioluminescence imaging system and immunohistochemical analysis. Our results show that cisplatin inhibits tumor growth by decreasing intratumoral vessel area but does not affect the angiogenesis ratio in the tumor. The vascular occupancy in the outer region of the tumor was larger than that in the inner region; however, both occupancies were similar to those of the control tumor. We propose that this method of mapping microvessels with ALs and an HF-US system can serve as a new molecular imaging method for the assessment of angiogenesis and can be applied to evaluate the antitumor effects by various therapeutic agents.

Characterisation of polymer-shelled microbubbles in wall-less flow phantom using high-frequency ultrasound and video microscopy

A high frequency ultrasound pulse echo system and a video microscope were combined to investigate the relationship between backscatter from polymer shelled ultrasound contrast agents (UCAs) and their diameter. Individual UCAs (manufactured by Point Biomedical or Philips Research) were imaged while being sonicated with 40 MHz tone bursts. The backscatter magnitude produced by the Philips UCAs was proportional to UCA size, which is consistent with theoretically predicted behaviour of encapsulated microbubbles driven at frequencies above resonance. Despite being smaller, the Point UCAs produced a backscatter magnitude twice that of Philips UCAs, indicating that Point UCAs might behave quasi-resonantly when excited at 40 MHz.

A File Reader for the VisualSonics Vevo 770 Digital RF Data

A C++ file reader for the VisualSonics Vevo® 770 high frequency ultrasound system is presented. The digital RF header file is read into an XML DOM representation, which can be serialized as XML, HTML, or accessed in C++ natively with data object binding. An InsightToolkit reader is also implemented.

Anterior segment OCT assisting new techniques in the field of corneal grafting

Abstract Purpose Optical coherence tomography (OCT) after extended use in diagnosis of retinal diseases has now become a new cross‐sectional imaging approach useful for anterior segment (AS) imaging. The potential advantages and limits using AS‐OCT in the field of corneal grafting are presented. Methods Systematic literature review search and clinical examples focused in the fields of corneal grafting procedures by using two different OCT systems (time domain and spectral domain). Results AS‐OCT technology, using 1310 nm wavelength, offers some advantages as compared to high frequency ultrasound system, the main being the absence of contact with the eye. It provides relatively accurate morphology and measurements of different structures of the AS and of the cornea. Morphometry of corneal structures is particularly useful in the preoperative evaluation lamellar keratoplasty procedures, including anterior lamellar keratoplasty, deep anterior lamellar keratoplasty and endothelial keratoplasty. Morphology of the transplant, accurate measurements of lamellar graft, interface profile evaluation and complication assessment, including posterior lamellar disc detachment are feasible. Conclusion AS‐OCT presents advantages in the clinical practice in the field of corneal disease and surgery. This technology alone should not substitute a comprehensive clinical examination but may offer valuable insights in the quantification and observation of fine details which can be obscured or not detectable during conventional slit‐lamp examination.

Descement's Membrane Detachment Diagnosis Using a Very High Frequency Ultrasound Scanning System.

A 74-year-old woman was referred to our institute due to persistent corneal edema after cataract surgery. Slit-lamp examination revealed severe total corneal edema (obscuring anterior chamber and iris). Using a very high frequency (VHF) ultrasound scanning system (Artemis 2, Ultralink LLC) descement's membrane detachment (DMD) was diagnosed. VHF ultrasound scanning system could be a useful instrument in detecting post-cataract surgery DMD especially in patients in which diagnosis is difficult due to significant corneal clouding.