US Scanner Research Articles

Utility of ultra-portable ultrasound devices for the risk-stratification of thyroid dysfunctions in an emergency setting.

We previously showed that the rapid TSH (rTSH) screening is able to detect a high prevalence of thyroid diseases in patients presenting to the Emergency department (ED), with a 7% prevalence of undiagnosed thyroid dysfunctions. The purpose of the present study is to implement our diagnostic flow-chart for thyroid dysfunctions in the ED with a rapid point-of-care thyroid ultrasound (rPOCUS). rPOCUS was performed by an app-based mobile ultrasound device (Lumify® by Philips Healthcare) in patients with suppressed rTSH undergoing urgent procedures requiring iodinate contrast media. Our results suggest that rPOCUS is cost- and time-effective for the management of patients with a newly diagnosed hyperthyroidism requiring urgent iodinated contrast media or amiodarone administration. Moreover, this handled US scanner avoided rTSH measurement in patients found to have a normal thyroid gland, and detected some incidental findings (nodules, heterogeneous echotexture), which would lead to further diagnostic investigations. We demonstrate, for the first time, that rPOCUS greatly improves the management of patients attending the ED, including the prompt characterization and correct treatment of hyperthyroidism, and the prevention of iodine-induced thyrotoxicosis.

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.

Risk Factors for Nonalcoholic Fatty Liver Disease among Patients Referred to Radiological Departments at Hail Hospitals, KSA

Background: Nonalcoholic fatty liver disease (NAFLD) incidence and prevalence have increased globally. The gravity of this chronic disease comes from its ability to progress to cirrhosis and hepatocellular carcinoma, which are rising rapidly. Genetic, demographic, environmental, and clinical factors are significant in the occurrence of NAFL. This study aimed to assess risk factors that affect the occurrence of NAFLD. Methods and Results: This cross-sectional study was carried out at hospitals in the Hail Region, KSA. It included 160 patients: 76 were considered as control (normal liver), and 84 suffered from fatty liver (according to a US image). Sonography was carried out using a US scanner with curvilinear transducers having a frequency of 3.5MHz. The following data were obtained: age, BMI, clinical history, including long-term medication of more than 3 months (oral antidiabetic medications, hormone replacement therapy for hyperthyroidism, and antihypertensive drug), T2D, viral hepatitis, liver span, lipidemia, metabolic disorders, and weight loss. The prevalence of NAFLD increases significantly among patients taking medications for a long time and T2D patients (P<0.001). Hepatomegaly is one of the most common physical examination findings of NAFLD (P<0.001). Conclusion: A periodic US examination is helpful because it can reveal fatty infiltration of the liver in the early stages to avoid fatal complications, especially for patients with long-term medication or T2D. Other studies with larger sample sizes and different known risk factors are needed to discover all risk factors for the KSA population.

Evaluation of Nonlinear Contrast Pulse Sequencing for Use in Super-Resolution Ultrasound Imaging.

The use of super-resolution ultrasound (SR-US) imaging greatly improves visualization of microvascular structures, but clinical adoption is limited by long imaging times. This method depends on detecting and localizing isolated microbubbles (MBs), forcing the use of a dilute contrast agent concentration. Contrast-enhanced ultrasound (CEUS) image acquisition times as long as minutes arise as the localization of thousands of MBs are acquired to form a complete SR-US image. In this article, we explore the use of nonlinear CEUS strategies using nonlinear fundamental contrast pulse sequencing (CPS) to increase the contrast-to-tissue ratio (CTR) and compare MB detection effectiveness to linear B-mode CEUS imaging. The CPS compositions of amplitude modulation (AM), pulse inversion (PI), and a combination of the two (AMPI) were studied. A simulation study combined the Rayleigh-Plesset-Marmottant (RPM) model of MB characteristics and a nonlinear tissue model using the k-Wave toolbox for MATLAB (MathWorks Inc., Natick, MA, USA). Validation was conducted using an in vitro flow phantom and in vivo in the rat hind-limb. Imaging was performed with a programmable US scanner (Vantage 256, Verasonics Inc., Kirkland, WA, USA) and customized to transmit a set of basis US pulses from which both B-mode US (frame rate (FR) of 800 Hz) and multiple nonlinear CPS compositions (FR of 200 Hz) could be assessed from identical in vitro and in vivo datasets using a near simultaneous method. The simulations suggest that MB characteristics, such as diameter and motion, help to predict which US imaging strategy will enhance MB detection. The in vitro and in vivo US imaging studies revealed that different subpopulations of polydisperse MB contrast agents were detected by linear imaging and by each different nonlinear CPS composition. The most effective single imaging strategy at a 200-Hz FR was found to be B-mode US imaging. However, a combination of B-mode US imaging with a nonlinear CPS imaging strategy was more effective in detecting MBs in vivo at all depths and was shown to shorten image acquisition time by an average of 33.3%-76.7% when combining one or more CPS sequences.

Online MR evaluation of inter- and intra-fraction uterus motions and bladder volume changes during cervical cancer external beam radiotherapy

Purpose/objective(s)The purpose of the study was to assess the uterus motions and bladder volume changes of fractional movements in cervical sites throughout the external beam radiotherapy (EBRT) treatment.Materials/methodsA prospective online MR imaging tracking study was conducted in EBRT 43 patients with at least 4 scans during each treatment (before: ultrasound scan, MRI scan, CBCT scan, after: MRI scan) were included. In order to improve the treatment repeatability, each patient was instructed to empty the bladder and drink 500 ml water 1 h before CT simulation and each treatment. If the ultrasound scan result reached the CT simulation volume of bladder, the treatment began. Bladder was outlined on the T2 weighted axial sequence and CBCT image by the two observers to avoid the influence of contouring. The data of bladder volume and scanning time were accurately recorded. The bladder volumes, filling rates and uterus motion were retrospectively analyzed by MIM software.ResultsInter-fraction variation of the bladder volume was significant (p < 0.0001). Intra-fraction mean increase of the bladder volume was modest (30 cc) but significant (p < 0.001). Both inter- and intra-fraction of the uterus motion were significant. The average time between the pre-and post-fraction MRI scans was 27.82 ± 7.12 min (range 10–55 min) for IMRT plans and 24.14 ± 5.86 min (range7-38 min) for VMAT plan. Average bladder filling rate was 3.43 ml/min. The bladder filling rate did not change significantly with the course of treatment, but the bladder was more intolerant.ConclusionThis is the most detailed assessment of intra-fraction and inter-fraction motion during EBRT for cervical cancer. Finally, this study will inform appropriate treatment margins for online adaptive radiotherapy. We suggest that at least one image scan is needed before the EBRT. The portable US scanner provides a quick but unreliable measurement of the bladder volume. There is a significant statistical difference between the results of ultrasonic scanning and that of image scanning.

Starting a pediatric contrast ultrasound service: made simple!

The addition of contrast US to an existing pediatric US service requires several preparatory steps. This overview provides a guide to simplify the process. Initially, it is important to communicate to all stakeholders the justifications for pediatric contrast US, including (1) its comparable or better diagnostic results relative to other modalities; (2) its reduction in procedural sedation or anesthesia by avoiding MRI or CT; (3) its reduction or elimination of radiation exposure by not having to perform fluoroscopy or CT; (4) the higher safety profile of US contrast agents (UCA) compared to other contrast agents; (5) the improved exam comfort and ease inherent to US, leading to better patient and family experience, including bedside US exams for children who cannot be transported; (6) the need for another diagnostic option in light of increasing demand by parents and providers; and (7) its status as an approved and reimbursable exam. It is necessary to have an UCA incorporated into the pharmacy formulary noting that only SonoVue/Lumason is currently approved for pediatric use. In the United States this UCA is approved for intravenous administration for cardiac and liver imaging and for vesicoureteric reflux detection with intravesical application. In Europe and China it is only approved for the intravesical use in children. All other applications are off-label. The US scanner needs to be equipped with contrast-specific software. The UCA has to be prepared just before the exam and it is important to strictly follow the steps as outlined in the packaging inserts in order to prevent premature destruction of the microbubbles. The initial training in contrast US is best focused on the frontline staff actually performing the US studies; these might be sonographers, pediatric or interventional radiologists, or trainees. It is important from the outset to educate the referring physicians about contrast US. It is helpful to participate in existing contrast US courses, particularly those with hands-on components.

Three-dimensional periodontal investigations using a prototype handheld ultrasound scanner with spatial positioning reading sensor

To demonstrate the feasibility of the 3D ultrasound periodontal tissue reconstruction of the lateral area of a porcine mandible using standard 2D ultrasound equipment and spatial positioning reading sensors. Periodontal 3D reconstructions were performed using a free-hand prototype based on a 2D US scanner and a spatial positioning reading sensor. For automated data processing, deep learning algorithms were implemented and trained using semi-automatically seg-mented images by highly specialized imaging professionals. US probe movement analysis showed that non-parallel 2D frames were acquired during the scanning procedure. Comparing 3 different 3D periodontal reconstructions of the same porcine mandible, the accuracy ranged between 0.179 mm and 0.235 mm. The present study demonstrated the diagnostic potential of 3D reconstruction using a free-hand 2D US scanner with spatial positioning readings. The use of auto-mated data processing with deep learning algorithms makes the process practical in the clinical environment for assessment of periodontal soft tissues.

Therapeutic response monitoring after targeted therapy in an orthotopic rat model of hepatocellular carcinoma using contrast-enhanced ultrasound: Focusing on inter-scanner, and inter-operator reproducibility.

PurposeTo assess therapeutic response monitoring after targeted therapy in an orthotopic rat model of hepatocellular carcinoma (HCC) using CEUS with focusing on inter-scanner and inter-operator reproducibility.Materials and methodsFor reproducibility, CEUS was performed using two different US scanners by two operators in sixteen rat models of HCC. Using perfusion analysis software (VueBox ®), eleven parameters were collected, and intra-class correlation coefficient (ICC) was used to analyze reproducibility. Then seventeen rat models of HCC were divided into treatment group (n = 8, 30 mg/kg/day sorafenib for five days) and control group (n = 9). CEUS was performed at baseline and 14 days after first treatment, and changes of perfusion parameters were analyzed.ResultsIn treatment group, CEUS perfusion parameters showed a significant change. The peak enhancement (PE, 2.50 x103±1.68 x103 vs 5.55x102±4.65x102, p = 0.010) and wash-in and wash out AUC (WiWoAUC, 1.07x105±6.48 x104 vs 2.65x104±2.25x104, p = 0.009) had significantly decreased two weeks after treatment. On the contrary, control group did not show a significant change, including PE (1.15 x103±7.53x102 vs 9.43x102± 7.81 x102, p = 0.632) and WiWoAUC (5.09 x104±3.25x104 vs 5.92 x104±3.20x104, p = 0.646). For reproducibility, the various degrees of inter-scanner reproducibility were from poor to good (ICC: <0.01–0.63). However, inter-operator reproducibility of important perfusion parameters, including WiAUC, WoAUC, and WiWoAUC, ranged from fair to excellent (ICC: 0.59–0.93) in a different scanner.ConclusionOur results suggest that CEUS is useful for assessment of the treatment response after targeted therapy and with fair to excellent inter-operator reproducibility.

Costly Consideration and Dynamic Choice Set Formation

Dynamic choices of cognitively constrained individuals have been ascribed, by the rational inattention theory, as being a filtering problem, in which the attentional intensity is consciously elected. Human attention, however, is not merely of voluntary intensity; it is rather of volitional placement nature. In this article, I study the implications of a dynamic theory of volitional attention describing individuals who choose among the alternatives that are induced by their attentional choices. Firstly, a consumer search application using US scanner data indicates that attentional choices are characterized by complementarities. Costs do not exclusively depend on the cardinality of consideration sets, but also on experience and similarities between considered items. Neglecting, thereby, attentional placement aspects potentially leads to misidentification of preference characteristics. Secondly, participation inertia in financial markets is revisited under the scope of volitional attention and a cultural-based argument of why it can be optimal not to participate is provided.

Three-dimensional US for Quantification of Volumetric Blood Flow: Multisite Multisystem Results from within the Quantitative Imaging Biomarkers Alliance.

Background Quantitative blood flow (QBF) measurements that use pulsed-wave US rely on difficult-to-meet conditions. Imaging biomarkers need to be quantitative and user and machine independent. Surrogate markers (eg, resistive index) fail to quantify actual volumetric flow. Standardization is possible, but relies on collaboration between users, manufacturers, and the U.S. Food and Drug Administration. Purpose To evaluate a Quantitative Imaging Biomarkers Alliance-supported, user- and machine-independent US method for quantitatively measuring QBF. Materials and Methods In this prospective study (March 2017 to March 2019), three different clinical US scanners were used to benchmark QBF in a calibrated flow phantom at three different laboratories each. Testing conditions involved changes in flow rate (1-12 mL/sec), imaging depth (2.5-7 cm), color flow gain (0%-100%), and flow past a stenosis. Each condition was performed under constant and pulsatile flow at 60 beats per minute, thus yielding eight distinct testing conditions. QBF was computed from three-dimensional color flow velocity, power, and scan geometry by using Gauss theorem. Statistical analysis was performed between systems and between laboratories. Systems and laboratories were anonymized when reporting results. Results For systems 1, 2, and 3, flow rate for constant and pulsatile flow was measured, respectively, with biases of 3.5% and 24.9%, 3.0% and 2.1%, and -22.1% and -10.9%. Coefficients of variation were 6.9% and 7.7%, 3.3% and 8.2%, and 9.6% and 17.3%, respectively. For changes in imaging depth, biases were 3.7% and 27.2%, -2.0% and -0.9%, and -22.8% and -5.9%, respectively. Respective coefficients of variation were 10.0% and 9.2%, 4.6% and 6.9%, and 10.1% and 11.6%. For changes in color flow gain, biases after filling the lumen with color pixels were 6.3% and 18.5%, 8.5% and 9.0%, and 16.6% and 6.2%, respectively. Respective coefficients of variation were 10.8% and 4.3%, 7.3% and 6.7%, and 6.7% and 5.3%. Poststenotic flow biases were 1.8% and 31.2%, 5.7% and -3.1%, and -18.3% and -18.2%, respectively. Conclusion Interlaboratory bias and variation of US-derived quantitative blood flow indicated its potential to become a clinical biomarker for the blood supply to end organs. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Forsberg in this issue.

Percutaneous Microwave Ablation of Hepatocellular Carcinoma

Background: Hepatocellular carcinoma (HCC) is the commonest primary cancer of the liver. Incidence is increasing and HCC has risen to become the 5th commonest malignancy worldwide and the third leading cause of cancer related death. According to the BCLC staging system image-guided tumor ablation is recommended in patients with early stage HCC. Microwave ablation (MWA), is a thermal ablative technique that has recently emerged as a new therapeutic option. The aim of this study was to evaluate the use of microwave ablation in hepatocellular carcinoma treatment and to assess the outcome. Methods: This study was carried out on 52 patients proved to have HCC who presented to Radiology Department in Alexandria University Hospitals. Microwave ablation was performed percutaneously under real-time ultrasound guidance using a GE LOGIQ 5 Pro US scanner (USA) with a 3.5–5 MHz probe, to completely destroy the tumor, as well as the surrounding 0.5–1.0 cm normal appearing liver tissue (safety margins). The patients were observed two hours before discharge. Contrast-enhanced triphasic CT imaging needed to be performed at 1 month after the ablation. Results: All patients completed the procedure safely. The outcome, as determined by dynamic CT performed 1 month after percutaneous MWA, was achieved in 66 (97%) of 68 lesions. The technical success rates for tumors smaller than 3 cm and those 3-5 cm were 97.2% (35 of 36 nodules) and 96.9% (31 of 32 nodules), respectively Conclusion: Thermal ablation, including radiofrequency ablation (RFA) and microwave ablation (MWA), have been shown to be effective for treating HCC. Microwave ablation is a safe, effective and promising technique and a good replacement to surgical interference for patients who are not amenable to surgical therapy.

Competition, business cycles, and price flexibility in grocery stores

We study how local competition affects price flexibility over the business cycle using a nationally representative US scanner database covering 2001 to 2011. We find that the entry of a grocery store has no significant effect on the frequency of price change at incumbent grocers in the same zip code, but the entry of a Walmart results in more frequent price changes. Looking across time, price change frequency increases during expansions and decreases during downturns; however, all else being equal, the presence of a Walmart mitigates much of this cyclical behavior, compared to other grocery store competitors that have no differential effect across the business cycle.

Super-Resolution Ultrasound Imaging of Skeletal Muscle Microvascular Dysfunction in an Animal Model of Type 2 Diabetes.

To evaluate the use of super-resolution ultrasound (SR-US) imaging for quantifying microvascular changes in skeletal muscle using a mouse model of type 2 diabetes. Study groups were young, standard chow-fed male C57BL/6J mice (lean group) and high fat diet-fed older mice (obese group). After an overnight fast, dynamic contrast-enhanced US imaging was performed on the proximal hind limb adductor muscle group for 10 minutes at baseline and again at 1 and 2 hours during administration of a hyperinsulinemic-euglycemic clamp. Dynamic contrast-enhanced US images were collected on a clinical US scanner (Acuson Sequoia 512; Siemens Healthcare, Mountain View, CA) equipped with a 15L8 linear array transducer. Dynamic contrast-enhanced US images were processed with a spatiotemporal filter to remove tissue clutter. Individual microbubbles were localized and counted to create an SR-US image. A frame-by-frame analysis of the microbubble count was generated (ie, time-microbubble count curve [TMC]) to estimate tissue perfusion and microvascular blood flow. The conventional time-intensity curve (TIC) was also generated for comparison. In vivo SR-US imaging could delineate microvascular structures in the mouse hind limb. Compared with lean animals, insulin-induced microvascular recruitment was attenuated in the obese group. The SR-US-based TMC analysis revealed differences between lean and obese animal data for select microvascular parameters (P < .04), which was not true for TIC-based measurements. Whereas the TMC and TIC microvascular parameters yielded similar temporal trends, there was less variance associated with the TMC-derived values. Super-resolution US imaging is a new modality for measuring the microvascular properties of skeletal muscle and dysfunction from type 2 diabetes.

Valuing the quantity and quality of product variety to consumers

This paper presents a new decomposition of the cost of living into price, variety-quality and variety-quantity components. Variety-quantity reflects the value to consumers of an increase in the number of products, while variety-quality measures the average attractiveness of new versus disappearing products. The decomposition is relevant to calculation of the CPI and understanding firms’ product development practices. Our empirical results, using a large US scanner data set, show that variety-quality change is the most important component of variety improvement. This reduced the cost of living by 1.34 percentage points per annum on average, while variety-quantity lowered it by 0.67 percentage points.

Price Dispersion and Demand Uncertainty: Evidence from US Scanner Data

I use the Prescott (1975) hotels model to explain variations in price dispersion across goods sold by supermarkets in Chicago. I extend the theory to accounts for the monopoly power of chains and for non-shoppers. The main empirical finding is that the effect of demand uncertainty on price dispersion is highly significant and quantitatively important: More than 50% of the cross sectional standard deviation of log prices is due to demand uncertainty. I also find that price dispersion measures are negatively correlated with the average price but are not negatively correlated with the revenues from selling the good (across stores and weeks) and with the number of stores that sell the good.

Sonographic characteristics of non-traumatic focal hourglass-like nerve constriction

To describe the sonographic phenomenon of the focal 'hourglass-like constriction' of the peripheral nerves (FCPN). The authors described 7 patients meeting the criteria for the diagnosis of neuralgic amyotrophy with unilateral FCPN identified with ultrasound in 4 cases and detected intraoperatively in 3 cases (preliminary ultrasound was not performed). The US scanner Sonoscape Pro mode gray scale in the transverse and longitudinal scanning, linear probe 8-15 MHz and Logiq9 scanner with elastography were used. FCPN was detected in the single nerve in 4 patients, in two nerves in 2 patients and in 3 nerves in one patient. Among all the nerves involved in the pathological process, the radial nerve and its branches were affected in 73% (8 nerves); the ulnar nerve was involved in 18% (2 nerves) and the musculo-cutaneous nerve in 9%. The length of the constriction of the peripheral nerve did not exceed 1.7 mm. The deformation coefficient (DC) of constriction area was 3.8 to .,9; the change in the elasticity in the form of an increase of DC to 5.9 when compared to the intact portion of the nerve and a decrease in echogenicity were observed in one patient. High-resolution ultrasound of the nerve can be an informative method for the diagnosis of idiopathic non-traumatic FCPN mononeuropathy.

The human placenta: Function and morphological assessments using ultrasound and magnetic resonance elastography

s / Placenta 45 (2016) 63e133 74 P1.6 THE HUMAN PLACENTA: FUNCTION AND MORPHOLOGICAL ASSESSMENTS USING ULTRASOUND AND MAGNETIC RESONANCE ELASTOGRAPHY Richard K. Miller , Stephan McAleavey , Juvenal Ormachea , Eva Pressman, Loralei Thornburg , David Dombroski , Jianhui Zhong, Marvin Doyley , Ronald W. Wood, Jonathan Carrol-Nellenback , Ollivier Hyrien , Philip Katzman , Christopher Stodgell , Kam Szlachetka, Henry Wang, Kevin Parker . University of Rochester School of Medicine and Dentistry, Rochester, New York, USA; University of Rochester Haijm School of Engineering, Rochester, New York, USA Objective: In utero evaluations of placental anatomy and function offer the promise of associating placental pathophysiology with neonatal outcomes, and thus potential for enhanced management of perinatal complications and improved long-term health of the mother and child. Ultrasound Elastography (USE) and Magnetic Resonance Elastography (MRE) provide means to evaluate tissue stiffness in utero. In conjunction with measures of vascular anatomy and perfusion, we can test mechanistic hypotheses about the relationship with anatomical function and deviations associated with disease states. For example, The Parker Hypothesis (Parker, Phys. Med. Biol. 59: 4443,14) proposes that viscoelastic measures of soft tissue stiffness are related to the fractal branching properties of the vascular anatomy. Methods: Term human placentae were obtained immediately upon delivery and evaluated directly either in a 3T GE MRI with Elastography or using a Siemens Antares US scanner and VF10-5 Probe with custom single track location shear wave elasticity imaging pulse sequences and accelerated processing. Other placentae were perfused through the umbilical cord and imaging, Doppler measures and elastography were conducted. At the end of the experiments, a barium gel was infused to enhance subsequent CT imaging of the fetal vasculature. Results: The utility of elastography in functional evaluation of the placenta are readily demonstrated in the following examples: 1) Placental tissue anomalies (e.g., infarcted areas) are stiff, and provided dramatic examples of the sensitivity USE and MRE methodologies for the detection of placental pathology; 2) Ex vivo placental perfusions have been used to relate placental stiffness to fetal vasculature when measured by USE, as seen when fetal vascular dynamics were pharmacologically manipulated. Clinical and high-resolution microCT systems can and have been used on placentae to provide additional post-delivery anatomical characterization and quantification of the vascular beds. These CT observations provide confirmation of in vivo Doppler US and the potential use of MR angiography for vascular characterization. We demonstrated that these datasets are amenable to automated identification and characterization of branching morphology, including centerline tree and Sholl analyses. Conclusion: These USE and MRE technologies enable promising new approaches for the prediction of risks during and after pregnancy. (Support: Goode Foundation) MRI localization of a placental infarct with associated elastographic ortho slice A: gross examination of placental lesion. B, MR segmented volume. C. Superimposed MRE. Yellow arrow directs attention to lesion.

Reliability of 2D ultrasound imaging associated with transient ShearWave Elastography method to analyze spastic gastrocnemius medialis muscle architecture and viscoelastic properties

The aim of the study was to assess the reliability of pennation angle (PA) and muscle thickness (MT) 2D measurements and of shear elastic modulus measurement, using ultrasound imaging (US). Those measurements were made on spastic gastrocnemius medialis muscle at rest and at maximal passive stretching, in post-stroke hemiplegic patients. The paretic side measurements were compared to non-paretic side. Fourteen patients took part in 2 inter-session reliability experiments, realized at a 7 days interval by the same operator. The Aixplorer ® Supersonic US scanner with the transient ShearWave Elastography (SWE) software was used. The stretching experiments were made manually and controlled by a goniometer. The reliability of the 2D measurements was good. The coefficient of variation (CV) was 6.30% for MT measurement at rest, 6.40% and 8.26% for PA at rest and at maximal passive stretching respectively. The reliability of the shear elastic modulus measurement in the sagittal plane was good only at rest with a CV of 9.86%, versus 40.58% at stretching. None of the shear elastic modulus measurements in the axial plane were good. At rest, MT and PA were weaker on the paretic side (14.25 ± 3.12 mm and 17.32 ± 5.10°) versus non-paretic side (16.30 ± 3.19 mm and 21.08 ± 5.05°) ( P < 0.0001 and P = 0.006). At rest, there was a small difference in the shear elastic modulus between the paretic side and the non-paretic side (5.40 ± 1.67 kPa versus 6.20 ± 2.18 kPa, P = 0.041). This is the first description of muscle spastic structure using SWE with Supersonic Shear Imaging. 2D US associated with SWE shows promise in terms of muscular atrophy quantification and muscle histological quality assessment. These structural properties reflect some of the functional abilities regardless of motor control. It should enable further research on therapies, which impact muscle tissue quality, such as botulinum neurotoxin injections.

Analysis of reproducibility of 2D Ultrasound imaging with transient ShearWave Elastography on spastic gastrocnemius medialis muscle in children with spastic hemiplegic cerebral palsy

The aim of the study was to assess the intra- and inter-operator reliability of pennation angle (PA) and muscle thickness (MT) 2D measurements and of shear elastic measurement, using ultrasound imaging (US). Those measurements were realised on spastic gastrocnemius medialis muscle at rest and at maximal passive stretching, in children with spastic hemiplegic cerebral palsy. The paretic side measurements were compared to the non-paretic side. Eight patients took part in 2 inter-session reliability experiments, realised at a 7 days interval by two different operators. The Aixplorer ® Supersonic US scanner with the transient ShearWave Elastography (SWE) software was used. The stretching experiments were made manually and controlled by a goniometer. The intra-operator reliability of the 2D measurements was good. Both operators found a coefficient of variation (CV) ≤ 7% and 6.04% for MT at rest and at maximal passive stretching respectively, ≤ 9.77% for PA at rest. The reliability of the shear elastic modulus measurement in the sagittal plane was only good at rest for both operators with a CV ≤ 9.82%, versus 25.29% at stretching. The inter-operator reliability of 2D measurements was good for MT exclusively (CV ≤ 9.69% for the two sessions and two operators). At rest, MT was weaker in the paretic side (10.17 ± 1.52 mm) versus non-paretic side (12.43 ± 2,85 mm) ( P < 0.0001), and the shear elastic modulus was stronger in the paretic side versus non-paretic side (29.45 ± 5.7 Kpa vs 23.77 ± 3.93 Kpa) ( P < 0.0001). This is the first description of muscle spastic structure in children with cerebral palsy using SWE with Supersonic Shear Imaging. 2D US associated with SWE contribute to assess muscular atrophy and muscle elasticity. These structural properties reflect some of the functional abilities regardless of motor control. It should enable further research on therapies which impact muscle tissue quality, such as botulinum neurotoxin injections, in children with cerebral palsy.

Is pneumoperitoneum the terra ignota in ultrasonography?

In most cases, pneumoperitoneum is caused by gastrointestinal perforation, which usually requires surgical treatment. Many authors believe that ultrasound imaging of pneumoperitoneum is at least as effective as conventional radiography, or even that its efficacy is superior. In such a situation, it is imperative to make this modality one of the main tools in the diagnostic arsenal of emergency medicine. This is the main aim of this paper. First, ultrasound anatomy of so-called thoracic-abdominal border is discussed. The equipment requirements emphasize that the diagnostic process can be conducted with the simplest portable US scanner, even without the Doppler mode. The technique of a US examination, the aim of which is to detect, free air in the peritoneal cavity is also simple and conducted with the patients lying down, either in the supine or lateral position. A convex transducer with the frequency of 3.5–5 MHz is applied above the lower intercostal spaces on the right and left side, to the epigastric region below the xiphoid process and in various sites of the abdominal wall. The most effective examination, however, is conducted in the left lateral position via the right intercostal spaces. The differential diagnosis on the right side under the diaphragm should include the presence of a subdiaphragmatic abscess with gas and a hepatic abscess with a similar content as well as transposition of the colon in between the diaphragm and the liver (Chilaiditi syndrome). It seems that the inclusion of a US examination to the E-FAST method in order to detect free gas in the peritoneal cavity is justified since it is a sign of gastrointestinal perforation in numerous cases, and is clinically as relevant as the presence of free fluid.