Linear Probe Research Articles

Ultrasound-guided sciatic nerve block injections in barred owl (Strix varia) cadavers

ObjectiveTo describe an ultrasound-guided approach to the sciatic nerve and the distribution of nerve staining using two injectate volumes of dye in barred owls. Study designDescriptive, randomized, assessor-blinded, cadaveric study. AnimalsTwelve barred owl cadavers. MethodsThe sciatic nerve was visualized with a 13-6 MHz linear ultrasound probe placed on the medial aspect of the proximal femur in barred owl cadavers. A needle was inserted at the proximal caudal thigh, and cranially advanced in-plane until the tip was immediately adjacent and ventral to the sciatic nerve. Eleven owls were injected bilaterally with a 1:1 solution of 1% methylene blue and 0.5% ropivacaine, with high-volume (HV; 0.4 mL kg–1) and low-volume (LV; 0.2 mL kg–1) treatments. Nerve staining ≥ 1 cm circumferentially was determined by dissection 15 minutes post-injection. The coelom was then opened to inspect for aberrant dye spread. In one barred owl cadaver, a 1:1 solution of 1% methylene blue and 74% ioversol contrast was injected, and computed tomography was performed immediately before and 15 minutes after injection for evaluation of injectate spread. ResultsThe HV treatment (0.4 mL kg–1) resulted in successful nerve staining in 100% of injections, whereas the LV treatment (0.2 mL kg–1) resulted in successful nerve staining in 91% of injections. There was no leakage of injectate into undesired locations (e.g. coelomic cavity) in any cadaver. Conclusions and clinical relevanceIn barred owls, the sciatic nerve can be visualized with ultrasound and injecting a ropivacaine/dye solution under ultrasound guidance successfully stained the sciatic nerve in the majority of cases. This technique holds potential for providing analgesia distal to the stifle joint; however, further investigations are necessary to evaluate its practical application in a clinical setting.

Triglyceride glucose index is associated with subclinical atherosclerosis and subclinical myocardial dysfunction in patients with newly diagnosed type 2 diabetes mellitus

BACKGROUND: Previous studies have shown that, the triglyceride glucose index (TyG index) is related with the development of cardiovascular disease.AIM: Our novel study aimed to determine whether the TyG index measured at the time of diagnosis conducted on newly diagnosed type 2 diabetic individuals and the relationship between TyG index and carotid intima media thickness, as well as both myocardial functions and epicardial adipose tissue was investigated.MATERIALS AND METHODS: The study included 105 individuals (58 F, 47 M; mean age 50.4±9.8 years) newly diagnosed with T2DM and 51 healthy subjects (30 females, 21 males, mean age 49.8±8.9 years) without any chronic disease as the control group. In addition to laboratory parameters, transthoracic echocardiography carotid intima-media thickness with linear vascular probe were examined in all individuals.RESULTS: TyG index was significantly higher in newly diagnosed type 2 diabetic individuals compared to the controls. There was a positive correlation between the TyG index and carotid intima-media thickness, epicardial fat thickness, HbA1c, Homa-IR, body surface area, waist circumference, hip circumference, body mass index and CRP. When diastolic functions were considered, there was a negative correlation with E/A and a positive correlation with E/e’ septal. TyG index was also negatively correlated with EF. Regression analysis revealed that age and TyG index were associated with an increase in carotid IMT thickness.CONCLUSION: TyG index measured at the time of diagnosis in newly diagnosed type 2 diabetic patients is also associated with subclinical atherosclerosis, deterioration in left ventricular systolic and diastolic functions.

Quantitative 2-Dimensionsal Digital Subtraction Venography for Venous Interventions: Validation in Phantom and In Vivo Porcine Models

PurposeTo determine the feasibility of using a 2-dimensional quantitative digital subtraction venography (qDSV) technique that employs a temporally modulated contrast medium injection to quantify blood velocity in phantom, normal, and stenotic porcine iliac vein models. Materials and MethodsBlood velocity was calculated using qDSV following temporally modulated pulsed injections of iodinated contrast medium and compared with Doppler ultrasound (US) measurements (phantom, in-line sensor; in vivo, diagnostic linear probe). Phantom evaluation was performed in a compliant polyethylene tube phantom with simulated venous flow. In vivo evaluation of qDSV was performed in normal (n = 7) and stenotic (n = 3) iliac vein models. Stenoses were created using endovenous radiofrequency ablation, and blood velocities were determined at baseline, after stenosis, after venoplasty, and after stent placement. ResultsIn the phantom model, qDSV-calculated blood velocities (12–50 cm/s) had very strong correlations with US-measured velocities (13–51 cm/s) across a range of baseline blood velocities and injection protocols (slope, 1.01–1.13; R2 = 0.96–0.99). qDSV velocities were similar to US velocities regardless of injection method: (a) custom injector, (b) commercial injector, or (c) hand injection. In the normal in vivo model, qDSV-calculated velocities (5–18 cm/s) had strong correlation (slope, 1.22; R2 = 0.90) with US-measured velocities (3–20 cm/s). In the stenosis model, blood velocities at baseline, after stenosis, after venoplasty, and after stent placement were similar on qDSV and US at all time points. ConclusionsVenous blood velocity was accurately quantified in a venous phantom and in vivo porcine models using qDSV. Intraprocedural changes in porcine iliac vein blood velocity were quantified with qDSV after creation of a stenosis and subsequently treating it with venoplasty and stent placement.

Establishment of a selective puncture method of the temporomandibular joint targeting the superior and inferior joint spaces using a human cadaver under the guidance of an ultrasound device

To investigate an ultrasound-guided selective puncture method for the temporomandibular joint (TMJ), targeting superior (SJS) and inferior joint spaces (IJS), using a human cadaver. The study utilized five cadavers donated by members of our university. The cadaver's left side was aimed at the SJS, while the right side was at the IJS. Nonionic contrast was injected into each joint using a crossing technique, with the linear ultrasound probe placed parallel to the long axis of the mandibular branch and punctured perpendicularly into the joint cavity. Cone-beam computed tomography scans assessed both the TMJs examining discs and other components for damage using a gross anatomical technique. Computed tomography images confirmed successful contrast agent injection into all joint spaces without damaging the articular discs or cartilage of the mandibular head. Our findings suggest that the ultrasound device can selectively puncture the TMJ in the SJS and IJS. In the future, the success rate is expected to improve with additional cadaver punctures. We aim to establish this technique as a viable treatment method that can be performed by oral surgeons with limited clinical experience in cadaver surgery training and a surgical technique training program using human cadavers.

Ultrasound-Guided Off-Plan Lumbar Seated Erector Spinae Plane Blocks : Are There Advantages?

The erector spinae plane block (ESPB) has been widely used as a treatment strategy for a variety of acute and chronic painful conditions. ESPBs are typically performed under ultrasound guidance [USG] in an in-plane long axis approach, targeting the tip of the lumbar transverse process while the patient lies prone. Off-Plane Seated Injection Technique-ESPB [OPSIT-E] represents a useful alternative in situations where a standard prone spine injection would be technically challenged by circumstances which may include morbid obesity, orthopnoea, recent upper limbs surgeries, chest pain from recent pacemaker implant, and in a subjects were in-plane approaches may be complicated by skin lesions. A seated forward flexed off-plane injection position, may also flatten the lumbar lordosis, shift adipose tissue more anteriorly, lessening skin to target distance and facilitating bony landmark identification, in high BMI and hyperlordotic subjects. The relatively larger curved transverse arc radius of the curvilinear probe [GE G1-5] in comparison to its transverse arc, also appears to offer improved central field of skin-transducer contact, earlier needle visualization, improved acute angle trajectory visualization of deep structures, which may be due to less crepuscular beam dispersion in comparison to transverse probe orientation. Even with a linear probe, the orthogonal technique facilitates a more perpendicular vector, lessening needle transit to target distance, which may in turn decrease procedure time, and improve patient comfort. The OPSITE, may also be easier to teach, learn, and master, as other studies have generally reported a higher rate of off-lane injection success among novice vascular interventionists.

Cranial ultrasound in preterm infants ≤ 32 weeks gestation—novel insights from the use of very high-frequency (18-5 MHz) transducers: a case series

The quality of cranial ultrasound has improved over time, with advancing technology leading to higher resolution, faster image processing, digital display, and back-up. However, some brain lesions may remain difficult to characterize: since higher frequencies result in greater spatial resolution, the use of additional transducers may overcome some of these limitations. The very high-frequency transducers (18-5 MHz) are currently employed for small parts and lung ultrasound. Here we report the first case series comparing the very high-frequency probes (18-5 MHz) with standard micro-convex probes (8-5 MHz) for cranial ultrasound in preterm infants. In this case series, we compared cranial ultrasound images obtained with a micro-convex transducer (8-5 MHz) and those obtained with a very high-frequency (18-5 MHz) linear array transducer in 13 preterm infants ≤ 32 weeks gestation (9 with cerebral abnormalities and 4 with normal findings). Ultrasound examinations using the very high-frequency linear transducer and the standard medium-frequency micro-convex transducer were performed simultaneously. We also compared ultrasound findings with brain MRI images obtained at term corrected age. Ultrasound images obtained with the very high-frequency (18-5 MHz) transducer showed high quality and accuracy. Notably, despite their higher frequency and expected limited penetration capacity, brain size is small enough in preterm infants, so that brain structures are close to the transducer, allowing for complete evaluation. Conclusion: We propose the routine use of very high-frequency linear probes as a complementary scanning modality for cranial ultrasound in preterm infants ≤ 32 weeks gestation.What is Known:• Brain lesions in preterm infants may remain insufficiently defined through conventional cranial ultrasound scan.• Higher frequency probes offer better spatial resolution but have a narrower filed of exploration and limited penetration capacity.What is New:• Very high-frequency probes were compared with standard medium-frequency probes for cranial ultrasound in infants ≤ 32 weeks' gestation.• Thanks to the smaller skull size of preterm infants, the new very high-frequency transducers allowed a complete and accurate evaluation.

Real-Time Phased Array Ultrasonic Monitoring of Debonding Growth Under Cycling Loading in CFRP

Carbon Fibre Reinforced Polymer (CFRP) composites are widely employed in diverse industries due to their specific stiffness and strength, and corrosion resistance. However, over time, service-induced damage can initiate a failure that can threaten the operation’s safety and reliability, especially in critical industries like aerospace applications. The challenge lies in identifying and monitoring the defects before they escalate into serious issues. Non-Destructive Testing (NDT) methods play a pivotal role in this scenario, aiming to detect and evaluate defects without causing harm to the material. Detecting flaws in composite materials such as CFRP remains a complex task. Traditional NDT methods often struggle to effectively pinpoint and assess defects within these intricate structures. However, recent advancements in ultrasonic testing, especially Phased Array Ultrasonic Testing (PAUT), show promise in examining the internal composition of CFRP composites with higher accuracy and reliability. This study aims to demonstrate the applicability of PAUT for real-time monitoring of debond growth under dynamic loading. The loading was applied to the test specimens up to one million cycles, and 64 elements 2 MHz linear phased array probe was attached to the specimen. The acquired signals were analyzed and could also be recorded for offline processing or archiving. To validate the credibility of the findings, the performance of PAUT was compared to Acoustic Emission (AE), a well-established method for detecting and analysing high-frequency signals emitted by materials undergoing deformation or damage. Encouragingly, both methods exhibited similar trends in capturing the growth of debond. Furthermore, to verify the final defect lengths, post-test ultrasonic C-Scans utilizing the through transmission technique were conducted, complemented by visual inspections. These assessments served to confirm the accuracy and reliability of the results obtained through Phased Array Ultrasonic Testing. Real-time monitoring of composite structures using phased array technology comprises a valuable tool for real- time assessment of debonding in the composite. As industries continue to rely on Carbon Fibre Reinforced Polymer composites for multifaceted applications, the utilization of advanced Non-Destructive Testing methodologies like Phased Array Ultrasonic Testing emerges as a cornerstone in guaranteeing their continued integrity and performance.

Association of inflammatory markers and ultrasonographic indicators of endothelial (dys)function in humans

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The Austrian Science Fund (FWF) Introduction It has been widely known that chronic inflammation is a crucial factor in the process of atherogenesis and atherosclerosis. Also, endothelial dysfunction presents the first and still reversible step of that process.(1) It is a challenge to find a laboratory marker whose levels would be informative about the extent of endothelial dysfunction and atherogenesis in humans. Purpose The aim of the present study was to determine associations between markers of chronic, low-grade inflammation and ultrasonographic indicators of endothelial (dys)function in healthy volunteers (H) and in patients with metabolic syndrome (MS). Methods Any kind of clinically manifest acute inflammatory or infectious disease, as well as chronic inflammatory, autoimmune or malignant disease was an exclusion criterion for participation. Serum levels of C-reactive protein (CRP) were measured using standard clinical chemistry analyser, and serum levels of interleukin-6 (IL-6) using electro-chemiluminescence immunoassay. Blood vessel wall function was quantified as flow-mediated dilation (FMD) and nitroglycerin-mediated dilation (NMD), which were measured automatically and continuously using the ultrasound device with linear probe (10 MHz) and the software for ultrasound blood vessel diameter analysis,(2) following currently valid guidelines.(3,4,5) Results A total of 130 individuals were enrolled in the study (65 H and 65 MS), with a median age of 56 (IQR 50.0, 60.0) years and 47.7% women in each group. CRP and IL-6 levels, although being very low and within the intervals that are considered normal in everyday clinical practice for both groups [CRP - H: 1.2 (0.6, 2.3), MS: 2.4 (1.2, 5.5) μg/mL; IL-6 - H: 2.3 (1.7, 3.0), MS: 4.1 (2.7, 6.8) pg/mL], were significantly higher in the MS compared to H (both p<0.001). The MS group also had significantly lower FMD (p=0.013) and NMD (p=0.033) compared to H. In H, IL-6 levels were significantly negatively correlated with FMD (r=-0.46, p<0.001), but not with NMD; whereas no significant associations of IL-6 levels with FMD or NMD were observed in the MS group. CRP levels were not significantly associated with FMD or NMD in neither the H nor MS group. Conclusion Higher IL-6 serum levels in the absence of acute inflammatory or infectious disease are significantly associated with lower FMD values among individuals with low risk for cardiovascular diseases, who are still considered healthy. Direct correlation is attenuated and lost among individuals with developed clinical signs of metabolic syndrome, probably due to its complex pathophysiology, as well as redundant and interdependent mechanisms contributing to the occurrence of endothelial dysfunction in such an environment. Further investigation on larger cohorts is needed to determine whether IL-6 serum levels could serve as a marker of endothelial dysfunction in individuals without clinically developed traditional risk factors and symptoms of cardiovascular disease.

Understanding the effects of microbubble concentration on localization accuracy in super-resolution ultrasound imaging.

Super-resolution ultrasound (SRUS) through localising and tracking of microbubbles (MBs) can achieve sub-wavelength resolution for imaging microvascular structure and flow dynamics in deep tissuein vivo. The technique assumes that signals from individual MBs can be isolated and localised accurately, but this assumption starts to break down when the MB concentration increases and the signals from neighbouring MBs start to interfere. The aim of this study is to gain understanding of the effect of MB-MB distance on ultrasound images and their localisation. Ultrasound images of two MBs approaching each other were synthesised by simulating both ultrasound field propagation and nonlinear MB dynamics. Besides the distance between MBs, a range of other influencing factors including MB size, ultrasound frequency, transmit pulse sequence, pulse amplitude and localisation methods were studied. The results show that as two MBs approach each other, the interference fringes can lead to significant and oscillating localisation errors, which are affected by both the MB and imaging parameters. When modelling a clinical linear array probe operating at 6 MHz, localisation errors between 20 and 30μm (∼1/10 wavelength) can be generated when MBs are ∼500μm (2 wavelengths or ∼1.7 times the point spread function (PSF)) away from each other. When modelling a cardiac probe operating at 1.5 MHz, the localisation errors were as high as 200μm (∼1/5 wavelength) even when the MBs were more than 10 wavelengths apart (2.9 times the PSF). For both frequencies, at smaller separation distances, the two MBs were misinterpreted as one MB located in between the two true positions. Cross-correlation or Gaussian fitting methods were found to generate slightly smaller localisation errors than centroiding. In conclusion, caution should be taken when generating and interpreting SRUS images obtained using high agent concentration with MBs separated by less than 1.7 to 3 times the PSF, as significant localisation errors can be generated due to interference between neighbouring MBs.

B- Mode Ultrasonography of Ocular Abnormalities in Dogs

Background: Ultrasonography is a simple, safe and non-invasive method to examine the internal structures of eye in case of opacity of otherwise clear ocular medium like cornea, aqueous, lens, and vitreous. Methods: 123 dogs with ocular abnormalities from March 2021 to October 2022, presented to the Division of Veterinary Surgery and Radiology were included in this study. All of the animals underwent a thorough ophthalmic examination along with B-scan ultrasonography of both the eyes using a 7.5 MHz linear probe. Result: Ultrasonography revealed thin hyperechoic lines and a thin hyperechoic rim of the lens, indicating early cataract changes and cortical cataract, respectively. Sixty-two dogs were found to be affected by cataract; 20 dogs were affected by the disease Phthisis bulbi; 16 dogs had a complete retinal detachment showing a typical “morning glory” sign; 10 dogs had vitreous haemorrhage; 6 dogs had a damaged eye with lens dislocation; and 5 dogs had choroidal melanoma and intraocular tumours in 4 dogs out of 123 observed dogs. Further, out of 62 cataract cases, 16 dogs were affected by cortical cataracts, 41 had nuclear cataracts, and 5 dogs were affected by morgagnian cataracts. Therefore, B-scan ultrasonography of the eye was a quick, safe, and accurate way to examine the pathology, especially when opaque media inhibit direct examination or when exophthalmos is evident and the normal anatomy of the eye.

Application of three-dimensional ultrasound technique in repairing dorsal foot wounds with medial sural artery perforator flaps

To investigate the accuracy of positioning perforator of medial sural artery with three-dimensional ultrasound technique guided by a wide band linear matrix array volume transducer probe before operation, and the effectiveness of the flap design based on this in repairing the dorsal foot wounds. Between January 2019 and December 2022, 30 patients with skin and soft tissue defects of the dorsal foot were treated. There were 19 males and 11 females, with an average age of 43.9 years (range, 22-63 years). There were 12 cases of traffic accident injury, 15 cases of heavy crushing injury, and 3 cases of machine injury. The time from injury to hospitalization was 1-8 hours (mean, 3.5 hours). The wounds in size of 5 cm×3 cm to 17 cm×5 cm were thorough debrided and covered with vacuum sealing drainage dressing. Then the wounds were repaired with the medial sural artery perforator flaps after no obvious infection observed. To obtain the complete three-dimensional image, the number and position of the medial sural artery perforator branches and the position of the main blood vessels in the muscle were detected and recorded by wide band linear matrix array volume transducer probe before operation. Suitable perforating branches were selected to design the flap and guide the flap incision on this basis. The size of the perforating flap ranged from 6 cm×4 cm to 18 cm×6 cm. The sensitivity and positive predictive value were calculated by comparing preoperative exploration with intraoperative observation of perforating branches, so as to evaluate the positioning accuracy of three-dimensional ultrasound technique. The donor sites were sutured directly in 25 cases and repaired with free skin grafting in 5 cases. The 60 perforating branches of medial sural artery were found before operation and 58 during operation in 30 patients. Among them, pre- and intra-operative perforations were consistent with 56. The sensitivity was 93.3% and positive predictive value was 96.6%. The intramuscular position and route of the main blood vessels were basically consistent with the pre- and intra-operative observation. All flaps survived and wounds healed by first intention. All incisions at the donor sites healed by first intention, and all skin grafts survived. All patients were follow up 9-24 months (mean, 14.7 months). The appearance, color, and texture of the flaps were good, and no obvious effect on wearing shoes and walking. At last follow-up, the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hind score ranged from 80 to 92, with an average of 87.5. The patient satisfaction was excellent in 29 cases and good in 1 case. The three-dimensional ultrasound technique guided by the wide band linear matrix array volume transducer probe can accurately locate the perforating branch of the medial sural artery, and the three-dimensional imaging is more intuitive, which can be used to guide the design and incision of the medial sural artery perforator flap.

Prospective measurement of the width of cerebrospinal fluid spaces by cranial ultrasound in neurologically healthy children aged 0–19 months

BackgroundUltrasound (US) is often the first method used to look for brain or cerebrospinal fluid (CSF) space pathologies. Knowledge of normal CSF width values is essential. Most of the available US normative values were established over 20 years ago, were obtained with older equipment, and cover only part of the age spectrum that can be examined by cranial US. This prospective study aimed to determine the normative values of the widths of the subarachnoid and internal CSF spaces (craniocortical, minimal and maximal interhemispheric, interventricular, and frontal horn) for high-resolution linear US probes in neurologically healthy infants and children aged 0–19 months and assess whether subdural fluid collections can be delineated.MethodsTwo radiologists measured the width of the CSF spaces with a conventional linear probe and an ultralight hockey-stick probe in neurologically healthy children not referred for cranial or spinal US.ResultsThis study included 359 neurologically healthy children (nboys = 178, 49.6%; ngirls = 181, 50.4%) with a median age of 46.0 days and a range of 1–599 days. We constructed prediction plots, including the 5th, 50th, and 95th percentiles, and an interactive spreadsheet to calculate normative values for individual patients. The measurements of the two probes and the left and right sides did not differ, eliminating the need for separate normative values. No subdural fluid collection was detected.ConclusionNormative values for the widths of the subarachnoid space and the internal CSF spaces are useful for evaluating intracranial pathology, especially when determining whether an increase in the subarachnoid space width is abnormal.

Imaging Approach in the Diagnostics and Evaluation of the Psoriasis Plaque: A Preliminary Study and Literature Review.

(1) Background: the aim of the study was to demonstrate its usefulness in the field of imaging evaluation of plaque morphology in psoriasis vulgaris, with an emphasis on the use of confocal microscopy and other advanced skin-imaging techniques. (2) Methods: we conducted a prospective study over two years (July 2022-April 2024), on patients diagnosed with moderate or severe psoriasis vulgaris, treated in the dermatology department of our institution. We selected 30 patients, of whom 15 became eligible according to the inclusion and the exclusion criteria. A total of 60 psoriasis plaques were analyzed by dermatoscopy using a Delta 30 dermatoscope and Vidix 4.0 videodermoscope (VD), by cutaneous ultrasound (US) using a high-resolution 20 MHz linear probe, and by confocal microscopy, along with histopathological analysis. (3) Results: the study included fifteen patients with vulgar psoriasis, diagnosed histopathologically, of whom six were women and nine were men, with an average age of 55. Between two and six plaques per patient were selected and a total of sixty psoriasis plaques were analyzed by non-invasive imaging techniques. Twelve lesions were analyzed with ex vivo fluorescence confocal microscopy (FCM), compared to histology. US showed that the hyperechoic band and the lack of damage to the subcutaneous tissue were the most common criteria. The epidermis and dermis were found to be thicker in the area of psoriasis plaques compared to healthy skin. Dermatoscopy showed that the specific aspect of psoriasis plaques localized on the limbs and trunk was a lesion with an erythematous background, with dotted vessels with regular distribution on the surface and covered by white scales with diffuse distribution. The presence of bushy vessels with medium condensation was the most frequently identified pattern on VD. Good correlations were identified between the histological criteria and those obtained through confocal microscopy. (4) Conclusions: the assessment and monitoring of patients with psoriasis vulgaris can be conducted in a more complete and all-encompassing manner by incorporating dermatoscopy, ultrasonography, and confocal microscopy in clinical practice.

High-Resolution Ultrasound of Odontogenic Cutaneous Sinus Tract: An International Multicentric Experience and a Review of the Literature.

To investigate the role of high-resolution ultrasound (HR-US) in the initial and differential diagnosis of the Odontogenic Cutaneous Sinus Tract (OCST) in a multicentric setting. Skin HR-US examinations of OCSTs performed between January 2019 and June 2023 at different Institutions were retrospectively reviewed. Epidemiological and clinical data (age, gender, location of the skin lesion, causative tooth, and the clinical suspicion) as well as HR-US imaging findings (morphology and length of the sinus tract, Doppler signal, and cortical bone interruption of maxilla or mandible) were collected. US examinations were performed by expert radiologists using a high-performance US scanner, employing a high-frequency linear probe (15 MHz or higher frequencies). In only one patient the HR-US exam was integrated with strain elastography (SE). Sixteen patients were enrolled with a median age of 37.6 years (range 16-70 years). The most frequent clinical suspicion was epidermal cyst, while OCST was suspected in only two cases. In all cases, HR-US depicted the sinus tract as a nodular, triangular or "champignon-shaped" lesion in the subcutaneous layer, which continued with a slightly tortuous band structure, up to the focally interrupted cortical bone plate. Furthermore, color Doppler evaluation showed color signals around and/or within the lesion, expression of inflammation. On SE, the sinus tract showed a hard pattern, due to fibrous and granulomatous tissue. HR-US, thanks to its high spatial resolution, allows the evaluation of OCST, and play a crucial diagnostic role, mainly when the clinical suspicious is different.

Optimum Parameters in Ultrasound Coherent Plane Wave Compounding for High LPWV Estimation: Validation on Phantom and Feasibility in 10 Subjects.

The aim of this study is to determine the optimum and fine values of the number and transmission angles of tilted plane waves for coherent plane-wave compounding (CPWC)-based high local pulse wave velocity (LPWV) estimation. A Verasonics system incorporating a linear array probe L14-5/38 with 128 elements and a pulsatile pump, CompuFlow1000, were used to acquire radio frequency data of 3, 5, 7, and 9 tilted plane wave sequences with angle intervals from 0° to 12° with a coarse interval increment step of 1°, and the angle intervals from 0° to 2° with a fine interval increment step of 0.25° from a carotid vessel phantom with the LPWV of 13.42 ± 0.90 m/s. The mean value, standard deviation, and coefficients of variation (CV) of the estimated LPWVs were calculated to quantitatively assess the performance of different configurations for CPWC-based LPWV estimation. Ten healthy human subjects of two age groups were recruited to assess the in vivo feasibility of the optimum parameter values. The CPWC technique with three plane waves (PRF of 12 kHz corresponding to a frame rate of 4000 Hz) with an interval of 0.75° had LPWVs of 13.52 ± 0.08 m/s with the lowest CV of 1.84% on the phantom, and 5.49 ± 1.46 m/s with the lowest CV of 12.35% on 10 subjects. The optimum parameters determined in this study show the best repeatability of the LPWV measurements with a vessel phantom and 10 healthy subjects, which support further studies on larger datasets for potential applications.

A study of carotid intima media thickness in patients with rheumatoid arthritis and its correlation with acute phase reactants and disease activity

Introduction: There is increased risk of cardiovascular morbidity and mortality in patients of rheumatoid arthritis (RA) due to accelerated atherosclerosis. In this study we measured Carotid artery intima media thickness (CIMT) as a surrogate marker for subclinical atherosclerosis in RA patients without pre-existing cardiovascular disease. This study also analyzed the correlation between CIMT, disease duration, Simplified Disease Activity Index (SDAI) and acute phase reactants. Methods: A cross-sectional study was conducted on 90 patients divided into two groups of 45 patients of RA and another 45 control subjects. Subjects with RA and age and sex matched healthy controls were included in the study without pre-existing CV risk factors. Complete clinical evaluation, hematological and biochemical profile done. ESR, CRP and platelet count were used as markers of acute phase reactants. All the RA patients included in the study were evaluated for their disease activity using Simplified Disease Activity Index (SDAI). All the subjects including the controls evaluated for carotid intima media thickness by using carotid ultrasonography. CIMT measured in common carotid artery bilaterally by examining throughout common carotid artery up to 2 cm proximal to bifurcation. CIMT measurement taken at the site of greatest thickness. All measurements taken in diastole, measured in phase when lumen diameter is at its smallest and IMT at its largest. Mean value of 6 readings (3 from each side) taken as final CIMT for evaluation. B mode (linear probe) USG was used to determine carotid IMT. Results: 45 cases and similar control subjects included in the study with mean age (SD) as 45.07 (14.81) years. We found female preponderance with 37 females out of 45 cases. Mean (SD) disease duration in male subjects was 5.38(2.40) years while in females was 5.09 (2.78) years. CRP was found to be significantly increased in cases group with mean (SD) of 5.75(8.85) mg/dl. ESR significantly raised to 35.22(13.55) mm/hour in cases group compared to control group where it was 16.16(5.71) mm/hr. Mean (SD) platelets (x10³/mm³) were 229.24(69.80) in cases while controls had 290.33(83.85), so platelets correlation with disease could not be established. CIMT was significantly raised in cases group. Mean (SD) CIMT in cases was 0.95(1.06) mm whereas in control group it was 0.60(0.16) mm with p value of 0.002. Moderate positive correlation was found between CIMT (mm) and SDAI and this correlation was statistically significant with p=0.001. For every 1 unit increase in CIMT, the SDAI increases by 2.92 units. A strong positive correlation between CIMT (mm) and Disease Duration (Years), and this correlation was statistically significant (rho = 0.9, p = <0.001). For every 1 unit increase in CIMT (mm), the Disease Duration (Years) increases by 1.26 units. Conversely, for every 1 unit increase in Disease Duration (Years), the CIMT (mm) increases by 0.19 units. Conclusion: A strong correlation was observed between CIMT and disease duration in rheumatoid arthritis. Hence, CIMT can be a useful surrogate marker for detecting atherosclerosis in patients with RA. In view of the relation to duration of disease, established RA patients should regularly be screened to identify the evidence of atherosclerosis and manage it earlier. Prevention of cardiovascular disease in RA requires an integrated approach encompassing cardiovascular risk factors screening and management, effective and sustained control of RA disease activity, high index of suspicion and prompt investigation of suspected cardiac disease.

In Vivo Human Lacrimal Gland Imaging Using an Ultrasound Biomicroscopy.

In the present study, we introduce human lacrimal gland imaging using an ultrasound biomicroscopy (UBM) with a soft cover and show their findings. The representative UBM findings of palpebral lobes in seven subjects (four with non-Sjögren dry eye syndrome, one with Sjögren syndrome, and two healthy subjects) were described in this study. To prolapse the palpebral lobe, the examiner pulled the temporal part of the upper eyelid in the superotemporal direction and directed the subject to look in the inferonasal direction. We scanned the palpebral lobes longitudinally and transversely using UBM. We used an Aviso UBM with a 50 MHz linear probe and ClearScan. In UBM of two healthy subjects, the echogenicity of the lacrimal gland was lower than that of the sclera and homogeneous. But the parenchyma of a patient with Sjögren dry eye syndrome was quite inhomogeneous compared to the healthy subjects. In two patients with dry eye syndrome, we were able to observe some lobules in the parenchyma. We could find excretory ducts running parallel at the surface of the longitudinal section in some subjects. In the longitudinal UBM scan of a subject, we observed a tubular structure at a depth of 1,500 μm that was considered a blood vessel. It ran from the superonasal to the inferotemporal direction. In a subject, we observed a large cyst beneath the conjunctiva. Lacrimal gland imaging using UBM has both advantages of optical coherence tomography and sonography, and could be useful for evaluating dry eye syndrome.

Comparison of Ultrasound Attenuation Imaging Using a Linear versus a Conventional Convex Probe: A Volunteer Study.

The study aimed to investigate the feasibility of attenuation imaging (ATI) measurements using a linear probe on healthy volunteers and compare measurements with the conventional convex probe. Attenuation imaging measurements of the liver tissue were taken using ultrasound with a convex and a linear probe in 33 volunteers by two examining doctors, and the measurements were repeated 4-5 weeks later by one of them. The ATI values for the linear probe were in the range of the values for the convex probe for both examiners. Measurements did not change significantly for 32 out of 33 volunteers after 4-5 weeks when using the linear probe. The size of the region of interest (ROI) only impacted the ATI values for the convex probe; it did not affect the values taken with the linear probe. Healthy volunteers were measured, and their attenuation values were compared to those from a convex probe, commonly used in steatosis evaluation. When both probes were positioned in the same liver area, they showed good agreement in attenuation values, though depth significantly affected the measurements, with both probes providing different values at different depths. The study's results aligned with previous research using the same system. Operator A and B's results were compared, demonstrating similar ranges of values for both probes. The linear probe has been demonstrated to allow for superficial measurements and attain ATI values in line with that of the convex probe in the liver.

Acute Neuropixels Recordings in the Marmoset Monkey.

High-density linear probes, such as Neuropixels, provide an unprecedented opportunity to understand how neural populations within specific laminar compartments contribute to behavior. Marmoset monkeys, unlike macaque monkeys, have a lissencephalic (smooth) cortex that enables recording perpendicular to the cortical surface, thus making them an ideal animal model for studying laminar computations. Here we present a method for acute Neuropixels recordings in the common marmoset (Callithrix jacchus). The approach replaces the native dura with an artificial silicon-based dura that grants visual access to the cortical surface, which is helpful in avoiding blood vessels, ensures perpendicular penetrations, and could be used in conjunction with optical imaging or optogenetic techniques. The chamber housing the artificial dura is simple to maintain with minimal risk of infection and could be combined with semichronic microdrives and wireless recording hardware. This technique enables repeated acute penetrations over a period of several months. With occasional removal of tissue growth on the pial surface, recordings can be performed for a year or more. The approach is fully compatible with Neuropixels probes, enabling the recording of hundreds of single neurons distributed throughout the cortical column.

To Compare the Efficacy of Sub-Pecto-Interfascial Block with Erector Spinae Plane Block in Postoperative Pain Management in Patients Undergoing Cardiac Surgery

Objectives: Pain following sternotomy has always been an issue of major concern for anesthesiologists. The incidence of pain is as high as 49% at rest following coronary artery bypass grafting. We planned to utilize the sub-pecto-interfascial plane (SIP) block and erector spinae plane (ESP) block to determine its efficacy and quality of analgesia as compared to conventional intravenous analgesia. Material and Methods: After the Institutional Ethics Committee’s approval, we recruited 105 patients and randomized them into three groups. Group 1 received conventional analgesia, group 2 SIP, and group 3 ESP block. Group 2 and Group 3 received allocated blocks after induction of balanced general anesthesia under ultrasound guidance. With high-frequency linear probe (13 MHz) planes identified, a mixture of injection ropivacaine (0.375%) and dexmedetomidine (1.1 mcg/mL) was deposited. In group 2, six injections of 6 mL each at the 2nd, 4th, and 6th intercostal spaces in the bilateral parasternal region. In group 3, two injections of 20 mL of the above-mentioned mixture on each side above the transverse process of the T5 vertebra under the erector spinae muscle plane were injected. All patients were monitored throughout the procedures, and their vitals were recorded. Heart rate, systolic blood pressure, and diastolic blood pressure were noted at baseline, at skin incision, at sternotomy, and 30 min post-extubation. Patients were followed for total fentanyl consumption, pain score (numerical rating scale [NRS] score), and peak inspiratory flow rate, which were noted at extubation and 2, 4, 6, 8, 12, and 24 hours post-extubation. Levels of C-reactive protein (CRP), cortisol, and prolactin were done at baseline and 24 h after surgery. Extubation time, time of first oral intake, and total length of intensive care unit (ICU) stay were also compared between the groups. Results: Total fentanyl consumption was significantly lower (P < 0.005) in group 2 and group 3 compared to group 1. Patient receiving blocks were significantly lower NRS score compared to the control group. Spirometry has shown improved results in block groups catering to early discharge from ICU. Rise in levels of CRP, cortisol, and prolactin were much higher in group 1 as compared to group 2 and group 3. Conclusion: The application of ESP and SIP blocks is far superior than conventional parenteral analgesics in terms of pain score, total opioid’s consumption, hemodynamic maintenance, spirometry efforts, and length of ICU stays.