High-frequency Ultrasound Research Articles

UHFUS: A Valuable Tool in Evaluating Exocrine Gland Abnormalities in Sjögren's Disease.

Sjögren's Disease (SjD) is a chronic autoimmune disorder that affects the salivary and lacrimal glands, leading to xerostomia and xerophthalmia. Ultrasonography of Major Salivary Glands (SGUS) is a well-established tool for the identification of the salivary glands' abnormalities in SjD. Recently, a growing interest has arisen in the assessment of the other exocrine glands with ultrasonography: lacrimal glands (LGUS) and labial salivary glands (LSGUS). The objective of this study is to explore the practical applications of ultra-high frequency ultrasound (UHFUS) in the assessment of lacrimal glands and labial salivary glands. Indeed, UHFUS, with its improved spatial resolution compared to conventional ultrasonography, allows for the evaluation of microscopic structures and has been successfully applied in various medical fields. In lacrimal glands, conventional high-frequency ultrasound (HFUS) can detect characteristic inflammatory changes, atrophic alterations, blood flow patterns, and neoplastic lesions associated with SjD. However, sometimes it is challenging to identify lacrimal glands characteristics, thus making UHFUS a promising tool. Regarding labial salivary glands, limited research is available with conventional HFUS, but UHFUS proves to be a good tool to evaluate glandular inhomogeneity and to guide labial salivary glands biopsy. The comprehensive understanding of organ involvement facilitated by UHFUS may significantly improve the management of SjD patients.

Ultra-High Frequency UltraSound (UHFUS) Assessment of Barrier Function in Moderate-to-Severe Atopic Dermatitis during Dupilumab Treatment.

Atopic dermatitis (AD) is a chronic multifactorial inflammatory disease characterized by intense itching and inflammatory eczematous lesions. Biological disease-modifying drugs, such as dupilumab are recommended for patients with moderate-to-severe AD, refractory to systemic immunosuppressive therapies. Disease monitoring is performed by clinical scores. Since 1970, however, the use of ultrasound and particularly high-frequency ultrasound (HFUS), has identified alterations in dermal echogenicity, called the subepidermal low-echogenic band (SLEB), that correlates with disease severity and response to treatment. We enrolled 18 patients with moderate-to-severe AD, divided into two groups: twelve patients in the dupilumab treatment (Group A) and six patients in standard treatment, from February 2019 to November 2019. We performed ultra-high frequency ultrasound (UHFUS) evaluation of lesional and non-lesional skin, focusing on SLEB average thicknesses measurement, epidermal thickness, and vascular signal in correlation with objective disease scores (EASI, IGA), patient's reported scores (Sleep Quality NRS and Itch NRS), and TEWL and corneometry at baseline (T0), after 1 month (T1) and 2 months (T2). The SLEB average thickness measurement, vascular signal, and epidermal thickness showed a statistically significant reduction in lesional skin of the biological treatment group and no significant reduction in non-lesional skin in both groups. In the lesional skin of the standard treatment group, only epidermal thickness showed a statistically significant reduction. Our study demonstrates that SLEB measurement, vascular signals, and epidermal thickness could be used as objective parameters in monitoring the AD treatment response, while the presence of SLEB in non-lesional skin could be used as a marker of subclinical inflammation and could predict development of clinical lesions, suggesting a pro-active therapy. Further follow-up and research are needed to clarify the association of SLEB decrease/disappearance with a reduction of flares/prolongment of the disease remission time.

A new method to estimate the histological stage of primary biliary cholangitis

ObjectiveTo analyze the diagnostic efficacy of the periportal hypoechoic band (PHB) in the histological stage of patients with primary biliary cholangitis (PBC).MethodsWe prospectively included 77 cases of PBC pathologically or clinically confirmed, and high-frequency ultrasound (HFUS) measurements of the PHB were performed in all included patients. Ludwig staging system of histopathology was used as the gold standard.ResultsThe width of the PHB was positively correlated with histological staging (r = 0.844, p < 0.001). By area under the receiving operating characteristic curve (AUROC), the best cutoff value for PHB for advanced stage (≥ stage 3) was 2.4 mm (AUROC: 0.934; 95%CI: 0.841–0.981) and 0.93 for sensitivity, and 0.91 for specificity, the concordance rates of PHB vs. liver biopsy was 90.3%. The correct rate for early-stage PBC was 87.9% and for the progressive stage was 93.1%. After multi-factor regression analysis, the PHB (OR = 1.331, CI = 1.105–1.603, p = 0.003) and total bilirubin (OR = 1.156, CI = 1.041–1.285, p = 0.007) were independent influencing factors for progressive PBC.ConclusionsMeasurement of the PHB to assess advanced PBC is a simple and effective method. This method may complement current methods for the histological staging assessment of patients with PBC.RegistrationClinical trial registration: ChiCTR 2000032053, 2020/04/19.Clinical relevance statementThe measurement of periportal hypoechoic band (PHB) provides a simple and easy assessment of the degree of disease progression in patients with PBC and provides an important clinical reference in predicting the histological staging of PBC from an ultrasound perspective.Key Points• The PHB is correlated with histological staging in the patient with PBC.• The area under the ROC curves of PHB for detecting advanced stage (≥ stage 3) were 0.934 and 0.93 for sensitivity, and 0.91 for specificity, the concordance rates of PHB vs. liver biopsy was 90.3%. The application of PHB can better assess the advanced PBC.• Measurement of the PHB to assess advanced PBC is a simple and effective method that can significantly reduce the need for liver biopsy.

Ultrasound characteristics of the cervical vagus nerve in patients with type 2 diabetes and diabetic peripheral neuropathy.

Diabetic peripheral neuropathy (DPN) and autonomic neuropathy are commonly coexistent in patients with type 2 diabetes mellitus (T2DM). Current assessment tools for diabetic neuropathy remain complicated and limited. We aimed to investigate the sonographic changes of the cervical vagus nerve in DPN patients with T2DM. Patients with T2DM were divided into a DPN group (DPN, n = 44) and non-DPN controls (NDPN, n = 43) based on electromyogram results. Another 43 healthy controls (CON) were included. High-frequency ultrasound (HFU) of the vagus nerve was performed in all participants. Compared with controls, the honeycomb structure of the vagus nerve in patients with T2DM decreased, p < 0.001. The DPN group had higher cross-sectional area (CSA) of the right vagus nerve than the NDPN group (1.60 ± 0.52 vs. 2.00 ± 0.57 mm2, p =0.001). Logistic regression showed that right vagus nerve CSA was a risk factor of DPN (odds ratio [OR] = 3.924, p = 0.002). Right vagus nerve CSA was positively correlated with diabetes duration (p = 0.003), and negatively correlated with the motor conduction velocity (MCV) of the ulnar, median, and common peroneal nerves (p < 0.001 for all), as well as the sensor conduction velocity (SCV) of the ulnar and median nerve (both p < 0.005). HFU shows thickening of the cervical vagus nerve in patients with DPN, which is a potential diagnostic feature of diabetic neuropathy.

A 2D Ultrasound Phased-Array Transmitter ASIC for High-Frequency US Stimulation and Powering.

Ultrasound (US) neuromodulation and ultrasonic power transfer to implanted devices demand novel ultrasound transmitters capable of steering focused ultrasound waves in 3D with high spatial resolution and US pressure, while having a miniaturized form factor. Meeting these requirements needs a 2D array of ultrasound transducers directly integrated with a high-frequency 2D phased-array ASIC. However, this imposes severe challenges on the design of the ASIC. In order to avoid the generation of grating lobes, the elements in the 2D phased-array should have a pitch of half of the ultrasound wavelength, which, as frequency increases, highly reduces the area available for the design of high-voltage beamforming channels. This article addresses these challenges by presenting the system-level optimization and implementation of a high-frequency 2D phased-array ASIC. The system-level study focuses on the optimization of the US transmitter toward high-frequency operation while minimizing power consumption. This study resulted in the implementation of two ASICs in TSMC 180 nm BCD technology: firstly, an individual beamforming channel was designed to demonstrate the tradeoffs between frequency, driving voltage, and beamforming capabilities. Finally, a 12-MHz pitch matched 12 × 12 phased-array ASIC working at 20-V amplitude and 3-bit phasing was designed and experimentally validated, to demonstrate high-frequency phased-array operation. The measurement results verify the phasing functionality of the ASIC with a maximum DNL of 0.35 LSB. The CMOS chip consumes 130 mW and 26.6 mW average power during the continuous pulsing and delivering 200-pulse bursts with a PRF of 1 kHz, respectively.

Echo intensity and gray-level co-occurrence matrix analysis of soft tissue grafting biomaterials and dental implants: an in vitro ultrasonographic pilot study.

To characterize different allogeneic and xenogeneic soft tissue graft substitutes and to assess their echo intensity and grayscale texture-related outcomes by using high-frequency ultrasonography (HFUS). Ten samples from each of the following biomaterials were scanned using HFUS: bilayered collagen matrix (CM), cross-linked collagen matrix (CCM), multilayered cross-linked collagen matrix (MCCM), human-derived acellular dermal matrix (HADM), porcine-derived acellular dermal matrix (PADM), collagen tape dressing (C) and dental implants (IMPs). The obtained images were then imported in a commercially available software for grayscale analysis. First-order grayscale outcomes included mean echo intensity (EI), standard deviation, skewness, and kurtosis, while second-order grayscale outcomes comprised entropy, contrast, correlation, energy and homogeneity derive from the gray-level co-occurrence matrix analysis. Descriptive statistics were performed for visualization of results, and one-way analysis of variance with Bonferroni post-hoc tests were performed to relative assessments of the biomaterials. The statistical analysis revealed a statistically significant difference among the groups for EI (p < .001), with the group C showing the lowest EI, and the IMP group presenting with the greatest EI values. All groups showed significantly higher EI when compared with C (p < .001). No significant differences were observed for energy, and correlation, while a statistically significant difference among the groups was found in terms of entropy (p < 0.01), contrast (p < .001) and homogeneity (p < .001). IMP exhibited the highest contrast, that was significantly higher than C, HADM, PADM, CCM and CM. HFUS grayscale analysis can be applied to characterize the structure of different biomaterials and holds potential for translation to in-vivo assessment following soft tissue grafting-related procedures.

Shear wave elastography-based skin assessment system for systemic sclerosis: a supplement or alternative to conventional ultrasound?

Although shear wave elastography (SWE) has been found to have the potential to evaluate skin lesions in systemic sclerosis (SSc), current research fails to answer the following questions: (I) can high-frequency ultrasound (HFUS) and SWE at multiple sites throughout the body distinguish SSc subtypes; (II) is HFUS and SWE at every site equally affected by clinical characteristics; and (III) is SWE a supplement or a choice to HFUS. This prospective study aimed to compare the value of SWE-based skin stiffness and HFUS-based skin thickness in distinguishing different SSc subtypes, verify the influence of clinical features on SWE and HFUS, and provide a basis for the screening of the optimal evaluation sites and indicators in the future. Forty-nine limited and 51 diffuse SSc patients were included in this study. Their skin was assessed at 17 sites by palpation using the modified Rodnan skin score (mRSS), skin thickness measured by HFUS, and skin stiffness by SWE. Clinical features, including age, sex, body mass index, and disease duration, were collected. The diffuse SSc patients had higher skin stiffness at most sites (P<0.05), except for the finger, foot, and forehead, and a thicker skin layer at most sites (P<0.05), except for the finger. The area under the curve (AUC) of HFUS, SWE, and the combination of the two in distinguishing diffused and limited SSc were 0.866, 0.921, and 0.973, respectively. The differences were statistically significant (combination vs. SWE, P=0.002, combination vs. HFUS, P=0.021). Longer disease duration was associated with a thinner skin layer at the forearm, arm, chest wall, abdominal wall, and thigh in limited SSc, including the leg in diffused SSc. SWE was less affected by clinical features than HFUS. SWE could achieve greater discrimination between different mRSSs at multiple sites, such as fingers and arms, than HFUS. For the assessment of SSc skin, SWE has several advantages over HFUS, including less influence by clinical features and greater sensitivity to discriminate different mRSSs. SWE has the potential to become a primary imaging assessment tool as well as HFUS.

Clinical, dermoscopic, and ultrasonic monitoring of the response to biologic treatment in patients with moderate-to-severe plaque psoriasis.

Assessment of therapeutic response of psoriasis has relied traditionally on clinical observation, and effective non-invasive tools are desirable. To investigate the value of dermoscopy and high-frequency ultrasound (HFUS) in the monitoring of psoriatic lesions treated with biologics. Patients with moderate-to-severe plaque psoriasis treated with biologics were evaluated by clinical, dermoscopic, and ultrasonic scores at weeks 0, 4, 8, and 12. Clinical scores, including Psoriasis Area Severity Index (PASI) and target lesion score (TLS), were evaluated at representative lesions. Dermoscopy was performed to assess the red background, vessels, and scales on a 4-point scale as well as the presence of hyperpigmentation, hemorrhagic spots, and linear vessels. HFUS was performed to measure the thicknesses of the superficial hyperechoic band and subepidermal hypoechoic band (SLEB). The correlation between clinical, dermoscopic, and ultrasonic evaluation was also analyzed. In total, 24 patients were analyzed and achieved 85.3 and 87.5% reduction of PASI and TLS, respectively, after 12 weeks of treatment. The red background, vessels, and scales scores under dermoscopy were reduced by 78.5, 84.1, and 86.5%, respectively. Some patients developed hyperpigmentation and linear vessels after treatment. Hemorrhagic dots slowly subside over the therapeutic course. Ultrasonic scores were significantly improved with an average reduction of 53.9% in superficial hyperechoic band thickness and 89.9% in SLEB thickness. TLS in the clinical variables, scales in dermoscopic variables, and SLEB in ultrasonic variables decreased the most significantly in the early stage of treatment (week 4) with 55.4, 57.7, and 59.1% (P > 0.05), respectively. Most of the variables, including the red background, vessels, scales, and SLEB thickness, were strongly correlated with TLS. High correlations were also found between the SLEB thickness and the red background or vessels scores, and between the superficial hyperechoic band thickness and the scales scores. Both dermoscopy and HFUS were useful in the therapeutic monitoring of moderate-to-severe plaque psoriasis.

Masseteric Nerve Ultrasound Identification for Dynamic Facial Reanimation Purposes.

The masseteric nerve is one of the main options to neurotize free muscle flaps in irreversible long-term facial paralysis. Several preoperative skin-marking techniques for the masseteric nerve have been proposed to limit the surgical dissection area, shorten the surgical time, and enable a safer dissection. However, these have shown variability among them, and cannot visualize the nerve preoperatively. The authors designed an observational study to validate a high-frequency ultrasound (HFUS) nerve identification technique. A systematic HFUS examination was designed and performed to visualize the masseteric nerve in 64 hemifaces of healthy volunteers. One-third were randomly selected to undergo an additional HFUS-guided needle electrostimulation to validate the HFUS image. The masseteric nerve was identified by HFUS in 96.9% of hemifaces (95% CI, 0.89 to >0.99) and showed almost perfect agreement with direct needle stimulation as calculated with Cohen kappa coefficient (0.95; 95% CI, 0.85 to 1.00). The masseteric nerve was found within the masseter muscle, in between the deeper muscle bellies, at 18.3 mm (SD ±2.2) from the skin. Only in 12.9% of cases (95% CI, 0.06 to 0.24) did its course become adjacent to the mandible periosteum. Other important features, such as disposition in relation to the parotid gland, or if the nerve was covered directly by a thick intramuscular aponeurosis, could be well observed by HFUS. HFUS enables masseteric nerve identification and can provide the surgeon with specific information on anatomical relations for each examined individual before surgery.

High Frequency Ultrasound of Basal Cell Carcinomas: Ultrasonographic Features and Histological Subtypes, a Retrospective Study of 100 Tumors.

(1) Background: 22 MHz high frequency ultrasound (HFUS) is a non-invasive imaging technique that gives information on depth, length, volume and shape of skin tumors. (2) Methods: We reviewed the clinical, ultrasound, and histological records of 54 patients with 100 histologically confirmed basal cell carcinoma (BCC) tumors with the use of HFUS. (3) Results: Most infiltrative tumors (n = 16/21, 76.2%) were irregular shaped, followed by five (23.8%) being round shaped; most superficial tumors (n = 25/29, 86.2%) were ribbon shaped, followed by four (13.8%) being round shaped; most nodular tumors (n = 26/33, 78.8%) were round shaped, followed by seven (21.2%) that were irregular shaped; and, lastly, all microdular tumors (n = 2/2, 100%) were round shaped. Strong evidence of association (p = 0.000) was observed between the histological subtype and tumor shape as seen using the HFUS. No evidence of association was found between the histological subtype and tumor margin (p > 0.005). Cohen's Kappa statistic to assess the agreement between BCC subtypes evaluated by histological examination and U/S appearance was calculated equal to 0.8251 (almost perfect agreement). (4) Conclusions: HFUS appears to be a reliable technique for the pre-operative evaluation of BCCs, assisting physicians to decide on the optimal therapeutic approach.

Super-Resolution Ultrasound Localization Microscopy Using High-Frequency Ultrasound to Measure Ocular Perfusion Velocity in the Rat Eye.

Imaging of the ocular vasculature can provide new insights into the pathophysiology of ocular diseases. This study proposes a novel high-frequency super-resolution ultrasound localization microscopy (SRULM) technique and evaluates its ability to measure in vivo perfusion changes in the rat eye at elevated intraocular pressure (IOP). A 38.4 MHz center frequency linear array transducer on a VisualSonics Vevo F2 imaging platform was used to collect high frame rate (1 kHz) radiofrequency data of the posterior rat eye following systemic microbubble contrast injection. Following clutter and spatiotemporal non-local means filtering, individual microbubbles were localized and tracked. The microbubble tracks were accumulated over 10,000 frames to generate vascular images quantifying perfusion velocity and direction. Experiments were performed using physiologic relevant controlled flow states for algorithm validation and subsequently performed in vivo on the rat eye at 10 mm Hg IOP increments from 10 to 60 mm Hg. The posterior vasculature of the rat eye, including the ophthalmic artery, long posterior ciliary arteries and their branches, central retinal artery and retinal arterioles and venules were successfully visualized, and velocities quantified at each IOP level. Significant reductions in arterial flow were measured as IOP was elevated. High-frequency SRULM can be used to visualize and quantify the perfusion velocity of the rat eye in both the retrobulbar and intraocular vasculature simultaneously. The ability to detect ocular perfusion changes throughout the depth of the eye may help elucidate the role ischemia has in the pathophysiology of ocular diseases such as glaucoma.

High frequency ultrasound assessment of skin in systemic sclerosis patients

To evaluate the role of high frequency ultrasound (HFU) in assessing skin changes in terms of thickness and echogenicity in systemic sclerosis (SSc) patients with early and late changes. Twenty-three SSc patients were enrolled along with 21 matched controls. Skin thickness was assessed using modified Rodnan skin score (mRSS) and HFU. Patients had mean age of 41.8 ± 9.1 years, 91.3% were females, mean disease duration 6.0 ± 4.6 years, 11 patients had early (<5 years) and 12 late (≥5 years) disease, 8 patients had limited (lcSSc) and 15 diffuse (dcSSc) cutaneous SSc. Antinuclear antibody was positive in 17 (73.9%) and antiscleroderma-17 in 18 (78.3%). Patients had significantly thicker skin between second and third metacarpophalangeal joint (L = 1.52 ± 0.35 mm vs 1.25 ± 0.35 mm; p = 0.017 and T = 1.48 ± 0.34 mm vs 1.26 ± 0.33 mm; p = 0.038 respectively). Patients with early disease had thicker skin than those with late disease. HFU dermal thickness showed no significant difference according to gender, subtypes, presence and absence of clinical manifestations or autoantibody positivity. There was significant higher dermal thickness in patients with reflux (p = 0.009) and was lower in patients with interstitial pulmonary fibrosis (p < 0.05). There was negative correlation between US dermal thickness and disease duration (p < 0.05). mRSS showed no correlation with HFU dermal thickness in all areas. HFU is useful in assessing skin pathologic changes (even subclinical changes) in terms of thickness and echogenicity in SSc patients. Moreover, it could be a potential screening tool in differentiating normal from pathologic skin thickness.

Value of High-Frequency Ultrasound in the Diagnosis of Pronator Teres Syndrome

Objective To investigate the clinical value of high-frequency ultrasound in the diagnosis of pronator teres syndrome (PTS). Methods The high-frequency ultrasound was employed to examine and measure the median nerve of the pronator teres muscle in 30 patients with PTS and 30 healthy volunteers (control group).The long-axis diameter (LA),short-axis diameter (SA) and cross-sectional area (CSA) of the median nerve were measured.The receiver operating characteristic curve of the median nerve ultrasonic measurement results was established,and the area under the curve (AUC) was calculated.The diagnostic efficiency of each index for PTS was compared with the surgical results as a reference. Results The PTS group showed larger LA[(5.02±0.50) mm vs.(3.89±0.41) mm;t=4.38,P=0.013],SA[(2.55±0.46) mm vs.(1.70±0.41) mm;t=5.19,P=0.009],and CSA[(11.13±3.72) mm2 vs.(6.88±2.68) mm2;t=8.42,P=0.008] of the median nerve than the control group.The AUC of CSA,SA,and LA was 94.3% (95%CI=0.912-0.972,Z=3.586,P=0.001),77.7% (95%CI=0.734-0.815,Z=2.855, P=0.006),and 78.8% (95%CI=0.752-0.821,Z=3.091,P=0.004),respectively.With 8.63 mm2 as the cutoff value,the sensitivity and specificity of CSA in diagnosing PTS were 93.3% and 90.0%,respectively. Conclusion High-frequency ultrasound is a practical method for diagnosing PTS,and the CSA of median nerve has a high diagnostic value.

Estimation of Mouse Carotid Arterial Wall Shear Stress Using High-Frequency Ultrasound Imaging.

Wall shear stress (WSS) is a crucial hemodynamic factor that promotes atherosclerosis (plaque) development in arteries; although the relationship between WSS and arterial atherosclerosis has been explored in many animal studies, it is not fully understood. No suitable tool, however, exists for rapidly estimating dynamic WSS in small-animal studies. This study proposes a 40-MHz high-frequency ultrasound (HFUS) imaging system for dynamic WSS estimation based on mouse carotid artery blood flow velocity gradient measurements by vector Doppler imaging (VDI). Aliasing reduces the accuracy of Doppler measurements, which can be prevented by increasing the imaging frame rate. Conventionally, imaging is performed at two tilted angles by alternating between the angles; in the proposed method, the frame rate was doubled by imaging at each tilted angle sequentially and by then temporally aligning the sequences based on pulsatile flow characteristics. Velocity estimation using this method had low errors for both a steady-flow straight-tube and pulsatile flow 60%-stenosis phantom. The method was tested for wild-type (WT) C57BL/6 mice at 16 weeks old and apolipoprotein E knockout (ApoE KO) mice at 16 and 24 weeks old; differences in time-averaged and oscillatory WSS were observed, and histology confirmed that the 24-week ApoE KO mice with the highest oscillatory WSS had the greatest plaque formation. The proposed HFUS WSS imaging method can predict the location and extent of plaque development; thus, this method is useful for small-animal studies investigating the WSS effect on atherosclerotic plaque development.

Value of High-Frequency Ultrasonography in the Qualitative and Semi-Quantitative Assessment of Immunoglobulin G4-Related Submandibular Sialadenitis.

To assess the value of high-frequency ultrasonography in the evaluation of immunoglobulin G4-related submandibular sialadenitis (IgG4-SS). Thirty-four submandibular glands in 17 patients with IgG4-SS were retrospectively enrolled, as well as 34 submandibular glands in 17 healthy control subjects. Qualitative ultrasonic features including submandibular gland size, border, echogenicity, and vascularity were reviewed. Two different scoring systems (0-16 and 0-48, respectively) were used for semi-quantitative analysis of imaging features. Comparison of both qualitative and semi-quantitative ultrasonic analysis were made between patients with IgG4-SS and healthy controls. Spearman correlation was used to explore relationships between variables. The submandibular glands with IgG4-SS presented with enlarged size, rough border, increased vascularity, and abnormal echogenicity (All P < .05). The most common echogenicity pattern for IgG-SS was diffuse hypoechoic foci pattern (44.1%), followed by superficial hypoechoic pattern (20.6%), tumor-like pattern (14.7%), and diffuse hypoechogenicity pattern (11.8%). Most IgG4-SS glands presented linear hyperechogenicity in parenchyma (91.2%). Based on both scoring system, scores of IgG4-SS were significantly higher than those of the controls (All P < .05). Association analysis of both scoring systems showed positive correlation of scores with vascularity in the gland parenchyma (All P < .05). The ultrasonic features of IgG4-SS comprise enlarged gland, rough border, increased vascularity, and abnormal echogenicity, which correlate with its pathological characteristics. The most common echogenicity pattern for IgG4-SS was diffuse hypoechoic foci pattern. Semi-quantitative analysis systems could be useful in the assessment of IgG4-SS. Ultrasound is a potential, valuable, and non-invasive tool for the diagnosis and evaluation of IgG4-SS.

Recognition of Object Presence and Material Type in a Water Container Using High Frequency Ultrasound

Detection and characterization of soluble, diffuse, and solid objects and their characteristics in water has important implications in various applications, including water quality assessment and incontinence monitoring for health applications. In particular in the latter task, it is essential to be able to non-intrusively detect the appearance, presence, and consistency of materials in the water without the need for special purpose instruments or a special purpose setting. To achieve this, this work investigates the potential use of high frequency sonar sensors retrofitted to an existing, water-filled container to detect and characterize events where materials are added to the water, and to classify characteristics of the materials in terms of solubility, granularity, and density.

Morphological aspects of basal cell carcinoma vascularization.

Basal cell carcinoma (BCC) is a malignant skin cancer which commonly exhibits aberrant blood flow because of angiogenesis. Its invasiveness and lack of metastatic potential may be explained by the typical pattern of vascularization seen in BCCs, where blood vessels are absent in the tumor islands and prominent in the tumor's periphery. From clinical point of view, high-frequency ultrasound (HFUS) is a useful tool for the evaluation of the lateral and depth extension of these tumors; furthermore, by employing color Doppler, important data regarding the vascularization degree of BCCs is provided. Knowingly, the sonographic vascular pattern of cutaneous tumors can aid in improving diagnosis and treatment by differentiating between benign and malignant lesions, between various types of cutaneous malignancies and also between various types of BCC (e.g., low risk versus high risk). Our aim was to perform a review integrating all currently known vascular properties of BCC as a tumor entity.

Advancing Process Intensification with High-Frequency Ultrasound: A Mini-Review of Applications in Biofuel Production and Beyond

High-frequency ultrasound (HFU) is an ultrasound technology with a frequency higher than 1000 kHz. It has become increasingly recognized as an emerging process intensification technology in various fields, such as biofuel production, carbon dioxide absorption, and wastewater treatment. HFU is seen as a potential intensifier technology for biofuel production, as its mechanisms, such as cavitational phenomena, microstreaming, and fountain formation, can benefit biofuel production. Previous research has shown that HFU can decrease the reaction time required for biofuel production, aid in lipid extraction, increase carbon dioxide absorption rates, and be effective in destroying pathogens in wastewater treatment. However, despite the potential benefits, there are limited reports on the use of HFU technology for biofuel production, which has led to uncertainties and constraints in its industrial deployment. These constraints include equipment design, economic analysis, and safety concerns, which require further in-depth analysis. Despite these limitations, previous studies have shown promising results for the incorporation of HFU into various fields due to its unique characteristics and mechanisms. This paper presents a review of the theory and application of HFU for process intensification, with a focus on its potential for biofuel production. It also provides recommendations for the further exploration of the technology to overcome industrial deployment obstacles.

Evaluation of Pericardial Thickening and Adhesion Using High-Frequency Ultrasound

Routine echocardiography using a standard-frequency ultrasound probe has insufficient spatial resolution to clearly visualize the parietal pericardium (PP). High-frequency ultrasound (HFU) has enhanced axial resolution. The aim of this study was to use a commercially available high-frequency linear probe to evaluate apical PP thickness (PPT) and pericardial adhesion in both normal pericardium and pericardial diseases. From April 2002 to March 2022, 227 healthy individuals, 205 patients with apical aneurysm (AA) and 80 patients with chronic constrictive pericarditis (CP) were recruited to participate in this study. All subjects underwent both standard-frequency ultrasound and HFU to image the apical PP (APP) and pericardial adhesion. Some subjects underwent computed tomography (CT). Apical PPT was measured using HFU and found to be 0.60±0.01mm (0.37-0.87mm) in normal control subjects, 1.22±0.04mm (0.48-4.53mm) in patients with AA, and 2.91±0.17mm (1.13-9.01mm) in patients with CP. Tiny physiologic effusions were observed in 39.2% of normal individuals. Pericardial adhesion was detected in 69.8% of patients with local pericarditis due to AA and 97.5% of patients with CP. Visibly thickened visceral pericardium was observed in six patients with CP. Apical PPT measurements obtained by HFU correlated well with those obtained by CT in those patients with CP. However, CT could clearly visualize the APP in only 45% of normal individuals and 37% of patients with AA. In 10 patients with CP, both HFU and CT demonstrated equal ability to visualize the very thickened APP. Apical PPT measured using HFU in normal control subjects ranged from 0.37 to 0.87mm, consistent with previous reports from necropsy studies. HFU had higher resolution in distinguishing local pericarditis of the AA from normal individuals. HFU was superior to CT in imaging APP lesions, as CT failed to visualize the APP in more than half of both normal individuals and patients with AA. The fact that all 80 patients with CP in our study had significantly thickened APP raises doubt regarding the previously reported finding that 18% of patients with CP had normal PPT.

Noninvasive imaging exploration of phacomatosis pigmentokeratotica using high-frequency ultrasound and optical coherence tomography: Can biopsy of PPK patients be avoided?

Phacomatosis pigmentokeratotica (PPK) is a distinct and rare type of epidermal nevus syndrome characterized by coexisting nonepidermolytic organoid sebaceous nevus (SN) with one or more speckled lentiginous nevi (SLN). Atypical nevi including compound Spitz and compound dysplastic may manifest within regions of SLN. Patients with PPK, or similar atypical nevus syndromes, may be subject to a significant lifetime number of biopsies, leading to pain, scarring, anxiety, financial burden, and decreased quality of life. The current literature includes case reports, genetics, and associated extracutaneous symptoms of PPK, but use of noninvasive imaging techniques have not been explored. We aim to investigate the value of high-frequency ultrasound (HFUS) and optical coherence tomography (OCT) in discriminating morphological features of pigmented lesions and nevus sebaceous within one patient with PPK. Two modalities, (1) HFUS imaging, based on acoustic properties and (2) OCT imaging, based on optical properties, were used to image a patient with PPK. Benign pigmented lesions, which may raise clinical suspicion for significant atypia, and nevus sebaceous, were selected on different areas of the body to be studied. Five pigmented lesions and one area of nevus sebaceous were imaged and analyzed for noninvasive features. Distinct patterns of hypoechoic features were seen on HFUS and OCT. HFUS provides a deep view of the tissue, with ability to differentiate gross structures beneath the skin. OCT provides a smaller penetration depth and a higher resolution. We have described noninvasive features of atypical nevi and nevus sebaceous on HFUS and OCT, which indicate benign etiology.