Quantitative pulsatility measurements using 3D dynamic ultrasound localization microscopy.

A rise in blood flow velocity variations (i.e. pulsatility) in the brain, caused by the stiffening of upstream arteries, is associated with cognitive impairment and neurodegenerative diseases. The study of this phenomenon requires brain-wide pulsatility measurements, with large penetration depth and high spatiotemporal resolution. The development of dynamic ultrasound localization microscopy (DULM), based on ULM, has enabled pulsatility measurements in the rodent brain in 2D. However, 2D imaging accesses only one slice of the brain and measures only 2D-projected and hence biased velocities . Herein, we present 3D DULM: using a single ultrasound scanner at high frame rate (1000-2000 Hz), this method can produce dynamic maps of microbubbles flowing in the bloodstream and extract quantitative pulsatility measurements in the cat brain with craniotomy and in the mouse brain through the skull, showing a wide range of flow hemodynamics in both large and small vessels. We highlighted a decrease in pulsatility along the vascular tree in the cat brain, which could be mapped with ultrasound down to a few tens of micrometers for the first time. We also performed an intra-animal validation of the method by showing consistent measurements between the two sides of the Willis circle in the mouse brain. Our study provides the first step towards a new biomarker that would allow the detection of dynamic abnormalities in microvessels in the brain, which could be linked to early signs of neurodegenerative diseases.

Dorsal Wrist Carpal Boss Impingement-Dynamic Ultrasound to the Rescue!

The "carpal boss" is a variant present in 19% of the population according to cadaveric studies but becomes symptomatic in only 1% of cases. With the rising popularity of "yoga," which includes prolonged hyperextension at the wrist joint with weight bearing, an increasing number of individuals with silent carpal boss present with dorsal wrist pain due to impingement over the dorsal soft tissues by this innocuous bony protuberance. This warrants the attention of radiologists and clinicians while dealing with wrist pain. It can be challenging to identify this bossing on routine radiographs, necessitating special views. We describe the use of dynamic ultrasound in diagnosing "symptomatic" carpal boss, the effects of which become even more evident on imaging during hyperextension-the triggering movement.

High-resolution ultrasound in the evaluation of the adult hip.

This paper reviews ultrasound of the hip, which is a commonly requested examination for symptomatic hip issues. This includes both intra-articular and extra-articular causes of hip pain. Ultrasound is easily accessible, lacks radiation exposure, and allows for evaluation of the contralateral hip as well as assessment of dynamic maneuvers. Ultrasound can be used to guide interventional procedures. Ultrasound of the hip can be challenging due to the deep location of structures and complex anatomy. Typically, high-frequency transducers are used to examine the hip, however the choice of ultrasound transducer depends on the patient's body habitus, with lower frequency transducers required to penetrate deep structures in obese patients. It is important to have an approach to ultrasound of the hip which includes assessment of the anterior, lateral, posterior, and medial aspects of the hip. The technique and relevant anatomy of each of these compartments are discussed as well as the use of Doppler examination of the hip. Several dynamic maneuvers can be performed to help determine the cause of hip pathology in various locations, and these are described and illustrated. Ultrasound is useful for guided procedures about the hip, and these indications will be reviewed.

Chronic changes in muscle architecture and aponeurosis structure following calf muscle strain injuries.

BACKGROUND: Muscle strain injuries in the human calf muscles are frequent sports injuries with high recurrence. Potential structural and functional changes in the medial head of the musculus gastrocnemius (GM) and the associated aponeurosis are not well documented. PURPOSE: To test whether a GM muscle strain injury affects muscle fascicle length, pennation angle, and the morphology of the deep aponeurosis at rest and during muscle contraction long time after the injury. Additionally, electromyography (EMG) of the GM and the soleus muscle during a unilateral heel rise was measured in the injured and uninjured calf. METHODS: GM fascicle length, pennation angle, and aponeurosis thickness was analyzed on dynamic ultrasonography (US) recordings in 10 participants with a chronic calf strain. In addition, US images taken across the distal portion and mid-belly of the GM were analyzed at three different ankle positions. EMG recordings were obtained during a unilateral heel rise. RESULTS: The pennation angle of the injured distal GM was significantly larger compared to the uninjured GM in the contracted, but not the relaxed state. Pennation angle increased more in the injured compared to the uninjured GM during contraction. Fascicle length was shorter in the most distal portion of the injured GM. Fascicles at the distal portion of the injured GM showed a pronounced curvilinear shape as the muscle contracted and the aponeurosis was enlarged in the injured compared to the uninjured GM. The ratio between GM and soleus EMG activity showed a significantly higher relative soleus activity in the injured compared to the healthy calf. CONCLUSION: The greater change in pennation angle and curvilinear fascicle shape during contraction suggest that a long-term consequence after a muscle strain injury is that some muscle fibers at the distal GM are not actively engaged. The significantly enlarged aponeurosis indicates a substantial and long-lasting connective tissue involvement following strain injuries.

Partial Flexor Tendon Injury Causing Locking: Illustration of the Utility of Dynamic Ultrasound.

Clinical diagnosis of partial flexor tendon lacerations is challenging because tendon function may be preserved. Although some partial flexor tendon tears can be managed conservatively, pain, stiffness, and triggering/locking may result, requiring surgical management. The mechanism by which this occurs has been investigated in animal and cadaver studies but has not been demonstrated in patients with real-time, in vivo imaging. Here, we present a case of partial tendon tear presenting with severe pain and locking that was diagnosed before surgery and characterized with dynamic ultrasound.

Genetic etiology and pregnancy outcomes of fetuses with central nervous system anomalies.

PURPOSE: To investigate genetic etiology and pregnancy outcomes of fetal central nervous system (CNS) anomalies. METHODS: 217 fetuses with CNS anomalies were included in our cohort from January 2016 to December 2022. 124 cases received karyotyping and 73 cases simultaneously underwent copy number variant sequencing (CNV-seq). Dynamic ultrasound screening and pregnancy outcomes were followed up, including neonates' neurodevelopmental outcomes. RESULTS: (1) 20 types of CNS anomalies were revealed by ultrasound and the most common was ventriculomegaly. (2) 14 (11.3%) of 124 cases were found chromosomal abnormalities by karyotyping, and copy number variations (CNVs) were revealed in 13 (17.8%) of 73 cases by CNV-seq. Fetuses with non-isolated CNS anomalies had a higher detection rate (DR) of abnormal karyotypes and CNVs than those with isolated CNS anomalies (25.0% vs. 4.8%; 35.0% vs. 11.3%) (P < 0.05). And the DR of abnormal karyotypes was significantly higher in multiple CNS anomalies than in single CNS anomaly (16.7% vs. 2.8%, P < 0.05), while there were no significant differences in the DR of CNVs. (3) Through dynamic ultrasound, 12 cases were further found progression or additional malformations. (4) Pregnancy outcomes of 209 cases were obtained, including 136 (65.1%) live births, 3 (1.4%) intrauterine fetal deaths, and 70 (33.5%) terminated. Two neonatal deaths at 6 months and one infant with motor and intellectual disabilities were finally found after long-term follow-up. CONCLUSION: Genetic analysis combined with dynamic ultrasound screening and multidisciplinary consultation plays an important role in evaluating the prognosis of fetal CNS anomalies, especially for those with multiple CNS or extracranial abnormalities.

Síndromes por atrapamiento del nervio intercostal y sus ramas / Entrapment syndromes of the intercostal nerve and its branches

El dolor torácico de origen musculoesquelético plantea un diagnóstico diferencial amplio, donde destaca la afectación de los nervios intercostales. Su atrapamiento o el de alguna de sus ramas puede asemejarse a un dolor visceral, por lo que puede pasar fácilmente desapercibido. Con una buena exploración y el uso de la ecografía dinámica, la aproximación diagnóstica puede ser más sencilla. Presentamos un varón de 40años valorado en consultas de Rehabilitación por dolor costal bajo derecho, desencadenado por ciertos movimientos y que asociaba una deformidad torácica tipo pectus excavatum. Mediante el uso de maniobras ecográficas dinámicas fue diagnosticado de neuralgia del séptimo nervio intercostal derecho secundaria a un atrapamiento dinámico en el contexto de una deformidad torácica con hipermovilidad costal. Desarrollamos la presentación clínica, las imágenes ecográficas, el tratamiento y la evolución tras el mismo. En este caso, se describen los síndromes por atrapamiento del nervio intercostal y de las ramas cutáneas, su diagnóstico clínico y ecográfico, y su abordaje terapéutico.(AU)

Musculoskeletal chest pain poses a broad differential diagnosis, among which intercostal nerve involvement stands out. Its entrapment or that of any of its branches can resemble visceral pain and therefore can easily go unnoticed. With a good examination and the use of dynamic ultrasound, the diagnostic approach can be simpler. We present a 40-year-old man evaluated in a rehabilitation department for right lower rib pain, triggered by certain movements and associated with a pectus excavatum type thoracic deformity. Using dynamic ultrasound maneuvers, he was diagnosed with neuralgia of the 7th right intercostal nerve secondary to dynamic entrapment in the context of a thoracic deformity with costal hypermobility. We describe the clinical presentation, ultrasound imaging, treatment, and evolution after treatment. In this case, we describe entrapment syndromes of the intercostal nerve and its branches, their clinical and ultrasound diagnosis, and their therapeutic approach.(AU)

Dynamic ultrasound assessment of hip instability and anterior and posterior hip impingement.

OBJECTIVE: In this technical report, we describe our protocol for the dynamic sonographic evaluation of the hip and assess reliability of the ultrasound assessment of hip microinstability. MATERIALS AND METHODS: Our clinical experience with a standardized dynamic ultrasound of the hip performed in a series of 27 patients with imaging performed by an experienced musculoskeletal radiologist during physical examination by an orthopedic surgeon specializing in hip preservation is illustrated with clinical photographs and ultrasound images from volunteers and selected patients. Interrater reliability for the diagnosis of microinstability was calculated. RESULTS: Dynamic ultrasound technique and findings of hip instability, femoroacetabular impingement, and ischiofemoral impingement with corresponding clinical photos showing the necessary physical examination maneuvers are described. Interrater agreement for the diagnosis of microinstability was substantial (κ 0.606 [0.221-0.991]). CONCLUSION: At our institution, dynamic ultrasound of the hip during physical examination complements information gathered from static imaging by providing real-time correlation of symptoms with what is occurring anatomically.

[Entrapment syndromes of the intercostal nerve and its branches]. / Síndromes por atrapamiento del nervio intercostal y sus ramas.

Musculoskeletal chest pain poses a broad differential diagnosis, among which intercostal nerve involvement stands out. Its entrapment or that of any of its branches can resemble visceral pain and therefore can easily go unnoticed. With a good examination and the use of dynamic ultrasound, the diagnostic approach can be simpler. We present a 40-year-old man evaluated in a rehabilitation department for right lower rib pain, triggered by certain movements and associated with a pectus excavatum type thoracic deformity. Using dynamic ultrasound maneuvers, he was diagnosed with neuralgia of the 7th right intercostal nerve secondary to dynamic entrapment in the context of a thoracic deformity with costal hypermobility. We describe the clinical presentation, ultrasound imaging, treatment, and evolution after treatment. In this case, we describe entrapment syndromes of the intercostal nerve and its branches, their clinical and ultrasound diagnosis, and their therapeutic approach.

A novel approach based on machine learning analysis of flow velocity waveforms to identify unseen abnormalities of the umbilical cord.

INTRODUCTION: A Doppler ultrasound (DUS) is essential for detecting blood flow abnormalities in the umbilical cord (UC). Any morphological abnormalities of the UC may lead to morbidity and stillbirth. Some abnormalities such as torsion, strictures and true-knot, however, may only be discovered at birth. This study proposes a novel approach of using machine learning analysis of flow velocity waveforms to improve the diagnosis of UC abnormalities. METHODS: A dynamic in-vitro simulator for DUS and three UC models, each representing a different morphology: true-knot, straight and coiled, were designed. DUS flow field images were captured from four cases of flow through the models: straight, coiled, at mid- and exit of the UC true-knot. The images were transformed into vector profiles of average flow signals that were segmented into 250 flow waves, each comprising 120 samples, for each of the four cases. Three sets of features were extracted from each flow wave and different machine learning algorithms were used for dimensional reduction and binary and multiclass classification. RESULTS: Significant differences were obtained between flow signals measured at the mid-knot compared to all other cases, which were also reflected in the average high accuracy rates of 97.5%-99.2%. Good accuracy rates of ∼80% and up were also generated, allowing the differentiation between the straight, coiled and exit true-knot. DISCUSSION: Our dynamic simulator can produce an unlimited database, and combined with the proposed machine learning analysis, may be used as decision support system and increase the ability to diagnose unseen pathologies of the UC.

How Paretic and Non-Paretic Ankle Muscles Contract during Walking in Stroke Survivors: New Insight Using Novel Wearable Ultrasound Imaging and Sensing Technology.

Abnormal muscle tone and muscle weakness are related to gait asymmetry in stroke survivors. However, the internal muscle morphological changes that occur during walking remain unclear. To address this issue, this study investigated the muscle activity of the tibialis anterior (TA) and medial gastrocnemius (MG) of both the paretic and non-paretic sides during walking in nine stroke survivors, by simultaneously capturing electromyography (EMG), mechanomyography (MMG), and ultrasound images, and using a validated novel wearable ultrasound imaging and sensing system. Statistical analysis was performed to examine the test−retest reliability of the collected data, and both the main and interaction effects of each "side" (paretic vs. non-paretic) and "gait" factors, in stroke survivors. This study observed significantly good test−retest reliability in the collected data (0.794 ≤ ICC ≤ 0.985), and significant differences existed in both the side and gait factors of the average TA muscle thickness from ultrasound images, and in the gait factors of TA and MG muscle's MMG and EMG signals (p < 0.05). The muscle morphological characteristics also appeared to be different between the paretic and non-paretic sides on ultrasound images. This study uncovered significantly different internal muscle contraction patterns between paretic and non-paretic sides during walking for TA (7.2% ± 1.6%) and MG (5.3% ± 4.9%) muscles in stroke survivors.

Usefulness of dynamic ultrasound in the diagnosis of epigastric herniation of stomach.

Introduction: Abdominal wall hernia contents usually consist of omental or mesenteric fat or loops of small or large bowel. Gastric involvement has been only rarely reported. Case report: We present a case of a 62-year-old woman who was admitted to our hospital due to epigastric pain and vomiting. On physical examination, the only observed abnormality was a soft, painless, epigastric bulge located in the upper midline. Based on the clinical presentation, the patient was diagnosed with a probable epigastric hernia. Dynamic ultrasound evaluation of the palpable bulge confirmed the presence of epigastric hernia demonstrating the movement of abdominal contents through a large wall defect. Surprisingly, the herniated contents were found to contain also the anterior wall of the distal stomach together with omental fat and vessels. The patient opted for surgery, which confirmed the presence of an epigastric hernia containing the distal portion of stomach. Discussion: In this case, dynamic ultrasound provided added value over computed tomography by clearly demonstrating stomach passing from the abdominal cavity to enter into the hernia sac and it is therefore reported for both its rarity and interest. To our knowledge, this is the first such ultrasound-based case report presented in literature and certainly the best sonographically documented. Conclusion: We anticiapte that this case report will promote the use of dynamic ultrasound in current practice as an effective imaging tool to recognise unusual types of hernias.

Old Dog, New Trick: Efficacy of Self-Directed Procedural Training for Attending Critical Care Physicians.

Background: In teaching hospitals, the majority of central venous lines (CVL) are placed by trainees, resulting in little opportunity for attending critical care physicians to maintain this procedural skill. Additionally, not all attending critical care physicians have been trained in the most up-to-date method of dynamic ultrasound (US) guided CVL placement. Furthermore, there is no standardized method to assess procedural competency of attending critical care physicians or to train them in the evolving practice of CVL placement. Despite these limitations, attending critical care physicians are ultimately responsible for supervision of CVL placement by trainees. Objective: To assess the utility of an instructional video to impact attending critical care physicians' competency and confidence in dynamic US guided CVL placement. Methods: A pre-post intervention study was conducted at an academic medical center. Attending critical care physicians were first asked to obtain CVL access on a gelatin model using US guidance. They then participated in the intervention, which consisted of watching a short instructional video demonstrating a method of dynamic US guided CVL placement. They were then asked to obtain access again, this time using the described method. All CVL placements were video recorded to assess competency in dynamic US guided CVL placement as well as the time required to obtain CVL access. Two blinded and independent reviewers evaluated each video with discrepancies resolved by a third reviewer. Participants were also surveyed pre and post intervention to assess their confidence in performing and supervising CVL placement. Results: A total of 21 attending critical care physicians were included. Pre-intervention, four used dynamic US guidance compared to 16 post-intervention (P < .001). Confidence in both CVL placement and supervision improved post-intervention (P = .03 each). Time required to obtain CVL access did not differ significantly pre and post intervention. The majority (20/21) believed there should be required competency testing for CVL placement. Conclusions: Pre-intervention dynamic US guided CVL competency was poor in this sample of attending critical care physicians but improved significantly with an instructional video intervention. This study suggests there is a role for procedural competency testing among attending critical care physicians, and that significant improvement is achievable with relatively minimal instruction.

Localized tenosynovial giant cell tumor: a rare case of snapping hip.

We report on a 40-year-old male with a 9-month-long history of snapping of his right hip caused by a previously undescribed etiology of internal extra-articular snapping hip, namely due to a localized tenosynovial giant cell tumor. Both dynamic ultrasound evaluation and MRI proved to be crucial in the diagnosis of this rare entity. Auto-provocation of the snapping showed an anterior hip mass moving posteriorly to the psoas tendon which elucidated the pain and clicking sensation. Subsequent MRI demonstrated a peripheral low-intensity rim due to hemosiderin deposition around the synovial mass which is indicative for pigmented villonodular tenosynovitis. Treatment consisted of arthroscopic shaver burr resection. Immediately postoperatively, the snapping sensation could not be provoked anymore by the patient. The purpose of reporting on this case report is to emphasize several successive learning points. First, dynamic ultrasound aids in diagnosis and differentiation of the types of snapping hip. Second, specific MRI features are suggestive of tenosynovial giant cell tumor, recognizing these traits may prevent delayed diagnosis and subsequent aggravated clinical course. Third, localized pigmented villonodular tenosynovitis around the hip may present as an internal extra-articular snapping hip and is of consideration in the differential diagnosis of recurrent snapping hip.

Dynamic Ultrasound Assessment of the Anterior Tibial Translation for Anterior Cruciate Ligament Tears Diagnostic.

The aim of our study was to investigate the accuracy of dynamic ultrasound assessment of the anterior tibial translation, in diagnosing anterior cruciate ligament tears, and to assess its test−retest reliability. Twenty-three patients (32 ± 8.42 years; 69.56% males) with a history of knee trauma and knee instability participated in the study. Knee ultrasound was performed by an experienced orthopedic surgeon. The anterior tibial translation was measured in both knees and differences between the injured and uninjured knee were calculated. Side-to-side differences > 1 mm were considered a positive diagnosis of an ACL tear. The anterior tibial translation values were 3.34 ± 1.48 mm in injured knees and 0.86 ± 0.78 mm in uninjured knees. Side-to-side differences > 1 mm were found in 22 cases (95.65%). The diagnosis accuracy was 91.30% (95%CI: 71.96−98.92%) and sensitivity 95.45% (95%CI: 77.15−99.88%). The intraclass correlation coefficient showed an excellent test−retest reliability (ICC3,1 = 0.97 for the side-to-side difference in anterior tibial translation). The study highlights the accuracy and reliability of the dynamic ultrasound assessment of the anterior tibial translation in the diagnosis of unilateral anterior cruciate ligament tears. Ultrasound assessment is an accessible imaging tool that can provide valuable information and should be used together with physical examination in suspected cases of ACL injuries.

Posttraumatic cicatricial sciatic nerve entrapment: dynamic imaging and percutaneous neurolysis.

We describe a case of late-onset sciatic neuralgia due to cicatricial tethering of the sciatic nerve by a retracted torn hamstring muscle that was successfully treated with percutaneous neurolysis. Ultrasound and MRI showed a chronic complete avulsion of the proximal hamstring complex with fatty atrophy of the retracted hamstring muscles. Dynamic ultrasound and magnetic resonance imaging displayed tethering of the retracted hamstring complex to the sciatic nerve caused by cicatricial adhesions. Whereas hamstring injuries are highly prevalent sports injuries, there are only a small number of reported cases in the literature of late-onset sciatic nerve involvement. We highlight the benefits of dynamic ultrasound and magnetic resonance imaging and propose ultrasound-guided percutaneous neurolysis as a viable minimally invasive treatment option.

Slipping rib syndrome: A clinical and dynamic-sonographic entity. A serial cases report.

BACKGROUND: Slipping rib syndrome (SRS) consists of false or floating rib hypermobility, which can force the ribs to come into contact with each other. OBJECTIVE: We aimed to examine each case by dynamic ultrasound to determine their ultrasound characteristics and analyze the clinical features of patients with SRS in order to better manage and follow them up. METHODS: Retrospectively, we collected 14 case series presenting to SRS between June 2016 and September 2018. The diagnosis was clinical and confirmed by dynamic ultrasound maneuvers. RESULTS: The mean age was 35.00 ± 10.66 years and 64.29% was male. The pain mechanism was caused by repetitive movements or a traumatic event. Dynamic ultrasound was considered a very useful tool for the diagnosis. Different conservative treatments were applied in most cases. Eco-guided infiltration was also an option. CONCLUSIONS: SRS should initially be based on a clinic suspicion in order to achieve a correct diagnosis and management. It is an underdiagnosed syndrome, so these case series contribute to our knowledge regarding this syndrome.

Urethral support in female urinary continence part 1: dynamic measurements of urethral shape and motion.

INTRODUCTION AND HYPOTHESIS: Urethral closure mechanism dysfunction in female stress urinary incontinence (SUI) is poorly understood. We aimed to quantify these mechanisms through changes in urethral shape and position during squeeze (voluntary closure) and Valsalva (passive closure) via endovaginal ultrasound in women with varying SUI severity. METHODS: In this prospective cohort study, 76 women who presented to our tertiary center for urodynamic testing as preoperative assessment were recruited. Urodynamics were performed according to International Continence Society criteria. Urethral pressures were obtained during serial Valsalva maneuvers. Urethral lengths, thicknesses, and angles were measured in the midsagittal plane via dynamic anterior compartment ultrasound. Statistical shape modeling was carried out by a principal component analysis on aligned urethra shapes. RESULTS: Age, parity, and BMI did not vary by SUI group. Ultrasound detected a larger retropubic angle, urethral knee-pubic bone angle (a novel measure developed for this study), and infrapubic urethral length measurements at Valsalva in women with severe SUI (p = 0.016, 0.015, and 0.010). Shape analysis defined increased "c" shape concavity and distal wall pinching during squeeze and increased "s" shape concavity and distal wall thickening during Valsalva (p < 0.001). It also described significant urethral shape differences across SUI severity groups (p < 0.001). CONCLUSIONS: Dynamic endovaginal ultrasound can visualize and allow for quantification of voluntary and passive urethral closure and variations with SUI severity. In women with severe SUI, excessive bladder neck and distal urethra swinging during Valsalva longitudinally compressed the urethra, resulting in a proportionally thicker wall at the mid-urethra and urethral knee.