High-resolution ultrasound and magnetic resonance imaging of ulnar nerve neuropathy in the distal Guyon tunnel.

OBJECTIVE: The aim of the present study is to describe the ultrasound (US) and magnetic resonance imaging (MRI) findings in patients with neuropathies affecting the deep (DB) and superficial (SB) branches of the Ulnar nerve (UN) and to investigate the potential role of imaging modalities in the diagnostic workup of these conditions. MATERIALS AND METHODS: We screened our institutional imaging database to identify patients with a diagnosis of UN mononeuropathy, and among them, we reviewed the cases where US disclosed pathological findings affecting the UN terminal divisions. In this latter subgroup, we retrieved available data on MRI and electrodiagnostic tests performed by the patients during the diagnostic workup. All the patients were evaluated with US machines equipped with 17-5-MHz, 18-4-MHz, 24-8-MHz, or 22-8-MHz probes. MRI exams were performed on a 3-T unit equipped with a 64-channel head RF coil. RESULTS: Among 166 patients with UN mononeuropathy, we retrieved 15 patients (9%) for which US detected pathological findings affecting the UN terminal divisions, consisting of 7 cases of DB neuropathy, 4 cases of SB neuropathy, and 4 cases of combined neuropathy involving both nerves. Seven (46.7%) patients were submitted to MRI to integrate US findings. Among patients with SB and DB neuropathies, imaging allowed the identification of 7 traumatic nerve injuries, 2 nerve tumors, and 6 entrapment neuropathies, including 4 cases of nerve compression by a ganglion cyst. CONCLUSION: High-resolution US and MRI are accurate modalities for the investigation of patients with SB/DB neuropathy, can provide critical information on the cause of nerve damage, and guide therapeutic decisions. CRITICAL RELEVANCE STATEMENT: High-resolution US and MRI are accurate modalities for the investigation of patients with superficial/deep branch of the ulnar nerve neuropathy. In the proper setting, US may be regarded as a first-line approach in patients with suspected neuropathies affecting these small branches. KEY POINTS: • Neuropathies affecting the distal ulnar nerve often require multimodal investigations. • US and MRI can provide detailed morphological information about the terminal branches of the ulnar nerve. • US may be considered as a first-line approach in suspected distal ulnar nerve neuropathies.

Adhesive Capsulitis of the Shoulder: Current Concepts on the Diagnostic Work-Up and Evidence-Based Protocol for Radiological Evaluation.

Adhesive capsulitis is an idiopathic and disabling disorder characterized by intense shoulder pain and progressive limitation of active and passive glenohumeral joint range of motion. Although adhesive capsulitis has been traditionally considered a diagnosis of exclusion that can be established based on a suggestive medical history and the detection of supporting findings at the physical exam, imaging studies are commonly requested to confirm the diagnostic suspicion and to exclude other causes of shoulder pain. Indeed, clinical findings may be rather unspecific, and may overlap with diseases like calcific tendinitis, rotator cuff pathology, acromioclavicular or glenohumeral arthropathy, autoimmune disorders, and subacromial/subdeltoid bursitis. Magnetic resonance imaging, magnetic resonance arthrography, and high-resolution ultrasound have shown high sensitivity and accuracy in diagnosing adhesive capsulitis through the demonstration of specific pathological findings, including thickening of the joint capsule and of the coracohumeral ligament, fibrosis of the subcoracoid fat triangle, and extravasation of gadolinium outside the joint recesses. This narrative review provides an updated analysis of the current concepts on the role of imaging modalities in patients with adhesive capsulitis, with the final aim of proposing an evidence-based imaging protocol for the radiological evaluation of this condition.

Ultrasound of the palmar aspect of the hand: normal anatomy and clinical applications of intrinsic muscles imaging.

Intrinsic hand muscles play a fundamental role in tuning the fine motricity of the hand and may be affected by several pathologic conditions, including traumatic injuries, atrophic changes induced by denervation, and space-occupying masses. Modern hand surgery techniques allow to target several hand muscle pathologies and, as a direct consequence, requests for hand imaging now carry increasingly complex diagnostic questions. The progressive refinement of ultrasound technology and the current availability of high and ultra-high frequency linear transducers that allow the investigation of intrinsic hand muscles and tendons with incomparable resolution have made this modality an essential tool for the evaluation of pathological processes involving these tiny structures. Indeed, intrinsic hand muscles lie in a superficial position and are amenable to investigation by means of transducers with frequency bands superior to 20 MHz, offering clear advantages in terms of resolution and costs compared to magnetic resonance imaging. In addition, ultrasound allows to perform dynamic maneuvers that can critically enhance its diagnostic power, by examining the questioned structure during stress tests that simulate the conditions eliciting clinical symptoms. The present article aims to review the anatomy, the ultrasound scanning technique, and the clinical application of thenar, hypothenar, lumbricals and interossei muscles imaging, also showing some examples of pathology involving these structures.

Ultrasound of the plantar foot: a guide for the assessment of plantar intrinsic muscles.

Plantar intrinsic muscles play a pivotal role in posture control and gait dynamics. They help maintain the longitudinal and transverse arches of the foot, and they regulate the degree and velocity of arch deformation during walking or running. Consequently, pathologies affecting the plantar intrinsic muscles (for instance, acquired and inherited neuropathies) lead to foot deformity, gait disorders, and painful syndromes. Intrinsic muscle malfunctioning is also associated with multifactorial overuse or degenerative conditions such as pes planus, hallux valgus, and plantar fasciitis. As the clinical examination of each intrinsic muscle is challenging, ultrasound is gaining a growing interest as an imaging tool to investigate the trophism of these muscular structures and the pattern of their alterations, and potentially to follow up on the effects of dedicated rehabilitation protocols. The ten plantar intrinsic muscles can be dived into three groups (medial, central and lateral) and four layers. Here, we propose a regional and landmark-based approach to the complex sonoanatomy of the plantar intrinsic muscles in order to facilitate the correct identification of each muscle from the superficial to the deepest layer. We also summarize the pathological ultrasound findings that can be encountered when scanning the plantar muscles, pointing out the patterns of alterations specific to certain conditions, such as plantar nerves mononeuropathies.

High-resolution US of the facial vessels with new facial vein landmarks for reconstructive surgery and dermal injection.

BACKGROUND: Accurate knowledge of vessel anatomy is essential in facial reconstructive surgery. The technological advances of ultrasound (US) equipment with the introduction of new high-resolution probes improved the evaluation of facial anatomical structures. Our study had these objectives: the primary objective was to identify new surgical landmarks for the facial vein and to verify their precision with US, the secondary objective was to evaluate the potential of high-resolution US examination in the study of both the facial artery and vein. METHODS: Two radiologists examined a prospective series of adult volunteers with a 22-8 MHz hockey-stick probe. Two predictive lines of the facial artery and vein with respective measurement points were defined. The distance between the facial vein and its predictive line (named mandibular-orbital line) was determined at each measurement point. The distance from the skin and the area of the two vessels were assessed at every established measurement point. RESULTS: Forty-one volunteers were examined. The median distance of the facial vein from its predictive line did not exceed 2 mm. The facial vein was visible at every measurement point in all volunteers on the right side, and in 40 volunteers on the left. The facial artery was visible at every measurement point in all volunteers on the right and in 37 volunteers on the left. CONCLUSIONS: The facial vein demonstrated a constant course concerning the mandibular-orbital line, which seems a promising clinical and imaging-based method for its identification. High-resolution US is valuable in studying the facial artery and vein. RELEVANCE STATEMENT: High-resolution US is valuable for examining facial vessels and can be a useful tool for pre-operative assessment, especially when combined with the mandibular-orbital line, a new promising imaging and clinical technique to identify the facial vein. KEY POINTS: • High-resolution US is valuable in studying the facial artery and vein. • The facial vein demonstrated a constant course concerning its predictive mandibular-orbital line. • The clinical application of the mandibular-orbital line could help reduce facial surgical and cosmetic procedure complications.

Recurrent motor branch neuropathy in carpal tunnel syndrome: An ultrasound study.

INTRODUCTION/AIMS: The reason for the variable rate of progression of patients with carpal tunnel syndrome (CTS) to thenar muscles impairment is not fully understood. The aim of this study was to evaluate the occurrence of ultrasound signs of recurrent motor branch (RMB) neuropathy in patients with CTS and to correlate imaging findings with clinical and electrophysiological data. METHODS: Two cohorts were recruited, one consisting of CTS patients with electrodiagnostic evidence of prolonged median distal motor latency from wrist to thenar eminence and another consisting of sex- and age-matched healthy controls. Ultrasound reliability of RMB measurement was assessed by the calculation of the interclass correlation coefficient (ICC). Patients were evaluated with electrodiagnostic tests and asked to complete the Boston Carpal Tunnel Questionnaire. The difference between the RMB diameter in patients and controls was analyzed using a t test. Correlations between RMB diameter and other parameters were assessed using linear mixed models. RESULTS: 46 hands from 32 patients with CTS and 50 hands from 50 controls were evaluated. The intra- and interobserver agreements in RMB measurement were very good (ICC = 0.84; 95% confidence interval [CI], 0.75 to 0.90) and good (ICC = 0.79; 95% CI, 0.69 to 0.87). The RMB diameter was significantly larger in patients than in controls (P < .0001). No significant correlation was found between the RMB diameter and other variables, except for BMI and median nerve cross-sectional area. DISCUSSION: Ultrasound is reliable in identifying the RMB and characterizing its abnormalities. In this patient cohort, ultrasound allowed for detection of definite signs of RMB compression neuropathy.

High-pressure injection injury of the hand: Clinical usefulness of ultrasound as an early diagnostic tool.

High-pressure injection injuries of the hand are uncommon accidents with potentially catastrophic complications. We present a case of a 49-years-old male with a high-pressure injection of motor oil in his left hand. Ultrasound accurately demonstrated soft tissue infiltration and late complications, playing a fundamental role in the treatment choice.

Imaging of Anatomical Variants Around the Wrist and Hand.

Wrist and hand anatomy may present several clinically relevant variants that involve bones, muscles, tendons, and nerves. Thorough knowledge of these abnormalities and their appearance in imaging studies is useful for proper management. In particular, it is necessary to differentiate the incidental findings that do not represent a trigger for a specific syndrome from those anomalies causing symptoms and functional impairment. This review reports the most common anatomical variants encountered in clinical practice and briefly discusses their embryogenesis, related clinical syndrome if present, and their appearance using different imaging techniques. The information each diagnostic study (ultrasonography, radiographs, computed tomography, and magnetic resonance imaging) may provide is described for each condition.

Immune checkpoint inhibitor-related pneumonitis and COVID-19: a case-matched comparison of CT findings.

OBJECTIVES: To compare the radiological findings of immune checkpoint inhibitor-related pneumonitis (IRP) and COVID-19 pneumonia, evaluating the potential of the CO-RADS score to differentiate between them. METHODS: Two readers blindly reviewed chest CTs from age- and sex-matched groups of 33 patients with IRP and 33 patients with COVID-19 pneumonia. Each examiner evaluated the presence of 13 CT features, semiquantitatively scored lung involvement, and assigned a CO-RADS score. Inter-reader reliability in the assessment of CT features and CO-RADS categories was evaluated with Cohen's κ. Distribution differences between groups were evaluated with the χ2, Fisher's, and Mann-Whitney U tests. RESULTS: Substantial or higher inter-reader reliability was found in CO-RADS assignments (κ = 0.664) and in the evaluation of CT features (κ ≥ 0.638), among which the sole feature found to significantly differentiate IRP from COVID-19 pneumonia was unilateral presentation (p < 0.001). Lung involvement semiquantitative scores and CO-RADS scores were significantly higher (p < 0.001) in COVID patients (median involvement score 4, IQR 4-6; median CO-RADS score 5, IQR 4-5) than in IRP patients (median involvement score 2.5, IQR 2-4; median CO-RADS score 3, IQR 3-4) but exploratory analysis of CO-RADS specificity revealed comparatively low values, ranging between 51.5% (Reader 1) and 54.6% (Reader 2). CONCLUSIONS: CT features of IRP and COVID-19 pneumonia frequently overlap, save for the extent of lung involvement and bilaterality. In the current SARS-CoV-2 pandemic, the low specificity of the CO-RADS score for the differential diagnosis of COVID-19 pneumonia and IRP may prompt to reconsider the role of imaging in IRP work-up.

High-Resolution Ultrasound of Facial Muscles: Sonoanatomy, Scanning Technique, and Pathological Cases.

The aim of the present work is to review the sonographic appearance of facial muscles with high-frequency transducers and to illustrate a step-by-step scanning technique that enables an effective evaluation of them. In addition, we highlighted the clinical application showing some pathological cases demonstrated with ultrasound (US). The recent technological advances have greatly enlarged the potential of high-resolution US in the evaluation of the face. Furthermore, the clinical indications of this technique are expected to increase in the near future.

High-resolution ultrasound of peripheral neuropathies in rheumatological patients: An overview of clinical applications and imaging findings.

Peripheral neuropathies are surprisingly common and can be associated with a number of conditions, including rheumatological diseases. Whether the co-existence of peripheral neuropathies with rheumatological disorders is coincidental or related to a common pathogenic mechanism, these disabling conditions can affect the outcome of rheumatological patients and should be targeted with specific treatment. The clinical presentation of peripheral neuropathy can be multifaceted and difficult to recognize in polysymptomatic patients. However, physicians adopting state-of-art diagnostic strategies, including nerve imaging, may improve the detection rate and management of neuropathies. In particular, a diagnostic approach relying exclusively on clinical history and nerve conduction studies may not be sufficient to disclose the etiology of the nerve damage and its anatomical location and thus requires integration with morphological studies. High-Resolution Ultrasound (HRUS) is increasingly adopted to support the diagnosis and follow-up of both joint disorders in rheumatology and peripheral neuropathies of different etiologies. In this review, the different types of nerve disorders associated with the most common syndromes of rheumatological interest are discussed, focusing on the distinctive sonographic features.

High-resolution Doppler ultrasound in systemic sclerosis: Analysis of digital arteries and nailfold microvasculature using 18-5 MHz and 33-9 MHz probes.

INTRODUCTION: Newly developed Doppler techniques enable the sampling of slow vascular flows and the extrapolation of spectral parameters in distal arterioles. The aim of this study was to investigate the role of spectral analysis performed by means of ultra-high frequency ultrasound (US) in the evaluation of the peripheral vascular bed of systemic sclerosis (SSc) patients. METHODS: Both hands of 33 patients affected by diffuse cutaneous SSc and 34 volunteers were evaluated with a US machine equipped with 33-9 MHz and 18-5 MHz transducers. Proximal resistive index and the peak systolic velocity (pRI and pPSV, respectively), were calculated at the level of the second interdigital artery. The distal resistive index (dRI) was calculated at the level of a nailfold arteriole of the third finger. All SSc patients had been previously divided into 4 subgroups according to their nailfold videocapillaroscopic (NVC) patterns following accepted criteria. RESULTS: SSc patients showed a significantly slower systolic velocity at the level of the second interdigital artery (pPSV [SD] = 8.38 [3] cm/s vs pPSV [SD] = 11.14 [4.5] cm/s; P = .005) and a higher dRI (dRI [SD] = 0.65 (0.14) vs dRI [SD] = 0.57 [0.11); P = .0115). No differences were found between the pRI values measured in the SSc patients and those of the controls (pRI [SD] = 0.76 [0.11] vs pRI [SD] = 0.73 [0.12]; P = .359]. The subgroup analysis did not show any significant difference when pPSV, pRI and dRI were compared among NVC morphological patterns. CONCLUSION: High-resolution Doppler analysis of digital distal arterioles may disclose subtle abnormalities in the downstream microvasculature of SSc patients that could be missed when the examination is performed at a more proximal level and/or using lower Doppler frequencies.

Outstanding Response in a Patient With ROS1-Rearranged Inflammatory Myofibroblastic Tumor of Soft Tissues Treated With Crizotinib: Case Report.

Inflammatory myofibroblastic tumor (IMT) is a very rare subtype of sarcoma, which frequently harbor chromosomal rearrangements, including anaplastic lymphoma kinase (ALK) rearrangements (almost 50% of the IMTs) and other kinase fusions such as ROS1. ROS1 fusions are present in about 10% of IMT, almost half of the ALK-negative IMT patients. Apart from radical surgery for resectable tumors, there is no standard-of-care therapy for advanced IMTs. Nonetheless, the use of tyrosine kinase inhibitors has shown promising efficacy in IMT patients with targetable genomic alterations. We report the case of a 24-year-old patient with chemotherapy-refractory metastatic IMT harboring ROS1 kinase fusion, who experienced a significant clinical and pathological response to crizotinib. This clinical case highlights the need to assess all patients with unresectable IMTs for chromosomal abnormalities and gene mutations and address them to targeted agents as well as clinical trials.

High-resolution ultrasound of spigelian and groin hernias: a closer look at fascial architecture and aponeurotic passageways.

From the clinical point of view, a proper diagnosis of spigelian, inguinal and femoral hernias may be relevant for orienting the patient's management, as these conditions carry a different risk of complications and require specific approaches and treatments. Imaging may play a significant role in the diagnostic work-up of patients with suspected abdominal hernias, as the identification and categorization of these conditions is often unfeasible on clinical ground. Ultrasound imaging is particularly suited for this purpose, owing to its dynamic capabilities, high accuracy, low cost and wide availability. The main limitation of this technique consists of its intrinsic operator dependency, which tends to be higher in difficult-to-scan areas such as the groin because of its intrinsic anatomic complexity. An in-depth knowledge of the anatomy of the lower abdominal wall is, therefore, an essential prerequisite to perform a targeted ultrasound examination and discriminate among different types of regional hernias. The aim of this review is to provide a detailed analysis of the fascial architecture and aponeurotic passageways of the abdominal wall through which spigelian, inguinal and femoral hernias extrude, by means of schematic drawings, ultrasound images and video clips. A reasoned landmark-based ultrasound scanning technique is described to allow a prompt and reliable identification of these pathologic conditions.

High-resolution ultrasound of the marginal mandibular branch of the facial nerve: Normal appearance and pathological findings in a postsurgical case series.

BACKGROUND: The aim of this study was to validate high-resolution ultrasound (US) as an imaging modality able to map the normal marginal mandibular nerve (MMN) and recognize its abnormalities in the postoperative setting. METHODS: The ability of US to recognize the MMN was first tested by injecting latex under US guidance on three fresh frozen cadavers. Then, a standardized scanning protocol was established on 20 healthy volunteers based on appropriate landmarks. Finally, a postsurgical series of three patients with MMN abnormalities were examined with US. RESULTS: In the cadaveric study, US-guided latex injection provided identification of the MMN. In healthy volunteers, US was able to recognize the MMN for a segment of 3.4 ± 1.2 cm in length. Pathologic abnormalities of the MMN were detected and characterized in three patients. CONCLUSIONS: High-resolution US is a valuable diagnostic tool to identify the MMN and might have potential for detecting its pathologic changes.

High-Resolution Ultrasound of Small Clinically Relevant Nerves Running Across the Posterior Triangle of the Neck.

With the advent of high-frequency ultrasound (US) transducers, new perspectives have been opened in evaluating millimetric and submillimetric nerves that, despite their dimensions, can be considered relevant in clinical practice. In the posterior triangle of the neck, the suprascapular, long thoracic, phrenic, supraclavicular, great auricular, lesser occipital, and transverse cervical nerves are amenable to US examination and the object of special interest because they may be involved in many pathologic processes or have a value as targets of advanced therapeutic procedures. The correct identification of these nerves requires a deep knowledge of local neck anatomy and the use of a complex landmarks-based approach with US. This article describes the anatomy and US technique to examine small but clinically relevant nerves of the posterior triangle of the neck (excluding the brachial plexus), reviewing the main pathologic conditions in which they may be involved.

Ultrasound Imaging Guide for Assessment of the Intrinsic Ligaments Stabilizing the Subtalar and Midtarsal Joints.

Ligament injuries around the subtalar, talocalcaneonavicular, and calcaneocuboid joints are often underestimated on clinical and imaging findings during investigation of patients with ankle and foot injuries. Because a delayed diagnosis of midtarsal ligament tears may lead to chronic pain and functional disability, an in-depth knowledge of the complex regional anatomy and of the appropriate ultrasound scanning technique is a prerequisite for evaluating these structures and avoiding misdiagnoses. The objective of this article is twofold: to describe the relevant anatomy and biomechanics related to the ligaments that stabilize the subtalar, talocalcaneonavicular, and calcaneocuboid joints, and to illustrate reasoned landmark-based scanning techniques to provide a systematic examination of these ligaments and thus make ultrasound an effective tool for assessment of patients with suspected subtalar or midtarsal sprain.

Breast Metastases: Updates on Epidemiology and Radiologic Findings.

Purpose The aim of this study was to report the prevalence of secondary breast malignancies and analyze their radiological characteristics. Materials and methods We collected 42,505 pathological reports of mammary biopsies performed from January 2000 to January 2019 in our hospital database, from which we screened reports of secondary cancer of the breast. We collected and analyzed imaging data from computed tomography (CT), ultrasound (US), and mammography. Mammograms, CT scans, and US images were reviewed by two breast radiologists. Prevalence of secondary breast malignancy among suspicious breast masses and all breast malignancies were calculated. Results Out of 42,505 histopathology reports from mammary biopsies, we found 19,354 malignancies. We identified 33 cases of secondary breast cancers (0.08% of suspicious breast lesions, 0.17% of breast malignancies). Most common metastases were from lymphoma (23 cases, 0.05% of suspicious breast lesions, 0.12% of breast malignancies) and melanoma (six cases, 0.01% of suspicious breast lesions, 0.03% of breast malignancies). All secondary lesions were hypoechoic on US and showed high density on mammogram. On CT, 83% of the lesions appeared solid/dense, and 17% were mixed, alternating areas of iso/hyperdensity with areas of hypodensity. Conclusion Secondary breast cancer had a prevalence of 0.17% among all breast malignancies. No specific imaging features, characteristic of secondary breast cancer, were found.