MRI-based Neuropathy Score Reporting And Data System (NS-RADS): multi-institutional wider-experience usability study of peripheral neuropathy conditions among 32 radiology readers.

OBJECTIVE: To determine the inter-reader reliability and diagnostic performance of classification and severity scales of Neuropathy Score Reporting And Data System (NS-RADS) among readers of differing experience levels after limited teaching of the scoring system. METHODS: This is a multi-institutional, cross-sectional, retrospective study of MRI cases of proven peripheral neuropathy (PN) conditions. Thirty-two radiology readers with varying experience levels were recruited from different institutions. Each reader attended and received a structured presentation that described the NS-RADS classification system containing examples and reviewed published articles on this subject. The readers were then asked to perform NS-RADS scoring with recording of category, subcategory, and most likely diagnosis. Inter-reader agreements were evaluated by Conger's kappa and diagnostic accuracy was calculated for each reader as percent correct diagnosis. A linear mixed model was used to estimate and compare accuracy between trainees and attendings. RESULTS: Across all readers, agreement was good for NS-RADS category and moderate for subcategory. Inter-reader agreement of trainees was comparable to attendings (0.65 vs 0.65). Reader accuracy for attendings was 75% (95% CI 73%, 77%), slightly higher than for trainees (71% (69%, 72%), p = 0.0006) for nerves and comparable for muscles (attendings, 87.5% (95% CI 86.1-88.8%) and trainees, 86.6% (95% CI 85.2-87.9%), p = 0.4). NS-RADS accuracy was also higher than average accuracy for the most plausible diagnosis for attending radiologists at 67% (95% CI 63%, 71%) and for trainees at 65% (95% CI 60%, 69%) (p = 0.036). CONCLUSION: Non-expert radiologists interpreted PN conditions with good accuracy and moderate-to-good inter-reader reliability using the NS-RADS scoring system. CLINICAL RELEVANCE STATEMENT: The Neuropathy Score Reporting And Data System (NS-RADS) is an accurate and reliable MRI-based image scoring system for practical use for the diagnosis and grading of severity of peripheral neuromuscular disorders by both experienced and general radiologists. KEY POINTS: • The Neuropathy Score Reporting And Data System (NS-RADS) can be used effectively by non-expert radiologists to categorize peripheral neuropathy. • Across 32 different experience-level readers, the agreement was good for NS-RADS category and moderate for NS-RADS subcategory. • NS-RADS accuracy was higher than the average accuracy for the most plausible diagnosis for both attending radiologists and trainees (at 75%, 71% and 65%, 65%, respectively).

Anatomy and Biomechanics of Lower Extremity Tendons: Imaging Implications.

A comprehensive understanding of the anatomy and biomechanics of muscle fibers and tendons is crucial to comprehend their functions. The orientation of tendon fibers plays a significant role in the pathologies that affect them and the resulting functional impairments. In this review, we provide detailed information on the origin, insertion, and fiber orientation of selected muscles and tendons, as well as their functional significance. To aid in comprehension, we have included illustrations depicting the anatomy and fiber orientation, as well as cross-sectional MR images that highlight important imaging features of normal anatomy and tears of select lower extremity tendons.

Multimodality Imaging for Diagnosing Transthyretin Cardiac Amyloidosis.

Amyloidosis is the result of the extracellular deposition of amyloid in various organs. Common types are light-chain and transthyretin amyloidosis. Cardiac amyloidosis (CA) is a restrictive cardiomyopathy caused by amyloid infiltration in cardiac tissues. The detection of CA is increasing with the advent of easily accessible imaging modalities. Early diagnosis ensures a better prognosis. We present a case of cardiac amyloidosis, diagnosed from specific imaging findings on cardiac magnetic resonance imaging and more precisely as transthyretin type based on findings on nuclear scintigraphy.

Neuropathy Score Reporting and Data System: A Reporting Guideline for MRI of Peripheral Neuropathy With a Multicenter Validation Study.

BACKGROUND. A standardized guideline and scoring system would improve evaluation and reporting of peripheral neuropathy (PN) on MRI. OBJECTIVE. The objective of this study was to create and validate a neuropathy classification and grading system, which we named the Neuropathy Score Reporting and Data System (NS-RADS). METHODS. This retrospective study included 100 patients with nerve imaging studies and known clinical diagnoses. Experts crafted NS-RADS using mutually agreed-on qualitative criteria for the classification and grading of PN. Different classes were created to account for the spectrum of underlying pathologies: unremarkable (U), injury (I), neoplasia (N), entrapment (E), diffuse neuropathy (D), not otherwise specified (NOS), and postintervention state (PI). Subclasses were established to describe the severity or extent of the lesions. Validation testing was performed by 11 readers from 10 institutions with experience levels ranging from 3 to 18 years after residency. After initial reader training, cases were presented to readers who were blinded to the final clinical diagnoses. Interobserver agreement was assessed using correlation coefficients and the Conger kappa, and accuracy testing was performed. RESULTS. Final clinical diagnoses included normal (n = 5), nerve injury (n = 25), entrapment (n = 15), neoplasia (n = 33), diffuse neuropathy (n = 18), and persistent neuropathy after intervention (n = 4). The miscategorization rate for NS-RADS classes was 1.8%. Final diagnoses were correctly identified by readers in 71-88% of cases. Excellent inter-reader agreement was found on the NS-RADS pathology categorization (κ = 0.96; 95% CI, 0.93-0.98) as well as muscle pathology categorization (κ = 0.76; 95% CI, 0.68-0.82). The accuracy for determining milder versus more severe categories per radiologist ranged from 88% to 97% for nerve lesions and from 86% to 94% for muscle abnormalities. CONCLUSION. The proposed NS-RADS classification is accurate and reliable across different reader experience levels and a spectrum of PN conditions. CLINICAL IMPACT. NS-RADS can be used as a standardized guideline for reporting PN and improved multidisciplinary communications.

A Late Presentation of COVID-19 Vaccine-Induced Myocarditis.

With the introduction of the coronavirus disease 2019 (COVID-19) mRNA vaccines, the incidence of severe infection has significantly decreased. While the vaccines have been shown to be effective and safe, there have been few case reports of acute myocarditis within 3-5 days following the second dose of the vaccine. We report a case of an elderly man who presented with acute-onset chest pain after three months of receiving the second dose of the mRNA vaccine. He was found to have acute myocarditis on cardiac magnetic resonance imaging (CMRI), which was attributed to exposure to the COVID-19 vaccine in the absence of any other risk factors. Our patient demonstrated quick resolution of symptoms and was discharged within 72 hours. We review the literature and summarize published case reports on COVID-19 vaccine-associated myocarditis. The present case report provides new evidence regarding the possible subacute presentation of myocarditis post-COVID-19 vaccine, and further highlights the favorable outcome in this newly described clinical entity.

Coronary-Cameral Fistula, Thebesian Veins, and Anomalous Coronary Vein on Cardiac Computed Tomography.

A 63-year-old female with a history of hypertension presented with progressively worsening shortness of breath. She underwent a cardiac catheterization and was found to have prominent Thebesian veins as well as anomalous connections between the proximal right coronary artery and the right ventricle. Cardiac computed tomography was ordered for further evaluation and showed a coronary fistula to the right ventricular outflow tract confirming the diagnosis of a coronary-cameral fistula (CCF). CCF are rare congenital anomalous communications that occur between coronary arteries and a cardiac chamber. They are usually an incidental finding and patients are rarely symptomatic. As the use of coronary computed tomography angiography is rapidly expanding, the detection of CCF will likely increase in the general population.

Tumor Occupancy Ratio-An Imaging Characteristic Prognosticating the Surgical Outcome of Benign Intradural Extramedullary Spinal Cord Tumors.

BACKGROUND: Intradural extramedullary (IDEM) spinal cord tumors are two thirds of all spinal tumors. We have prospectively analyzed the importance of the tumor occupancy ratio as a factor for predicting the course of the disease and in prognosticating the surgical outcome in patients with IDEM tumors. METHODS: We prospectively analyzed 44 consecutive cases of IDEM tumors, diagnosed as cervical, thoracic, and lumbar IDEM tumors (excluding conus/cauda equina lesion) by magnetic resonance imaging (MRI), that were operated on at our institution between 2014 and 2016. We measured the tumor occupancy ratio and noted the sagittal and axial location of the tumor in the preoperative MRI and performed the laminectomy and unilateral medial facetectomy. A primary outcome has been noted according to the gait disability score in the preoperative period and in the follow-up period of 1 year. In the statistical analysis, categorical variables were compared using a chi-square test, and an analysis of variance and student t tests were used for the continuous variables. P < .05 was considered statistically significant. RESULTS: The tumor occupancy ratio showed a significant association to the preoperative gait disability score (P < .001) and also predicted that the surgical outcome is much better in patients with tumors with a low tumor occupancy ratio than in patients with tumors with a high occupancy ratio (P < .001). No difference in the tumor occupancy ratio was noted in 2 different pathological tumors, and there was also no difference in the tumor occupancy ratio at different sagittal and axial locations of the tumor. CONCLUSION: Tumor occupancy ratio has shown a significant impact on the preoperative course and also predicts the surgical outcome in patients with IDEM tumors. Hence, it is an important imaging characteristic to prognosticate the outcome in IDEM tumors and should be noted in each case.

Congenital Mobile Atlantoaxial Dislocation with Cervicomedullary Astrocytoma in Pediatric Patient.

Congenital mobile atlantoaxial dislocation with cervicomedullary astrocytoma has never been described. We present a case of a 7-year-old male child who presented to us with gradually progressive spastic quadriparesis following a fall from table. His lateral radiograph and magnetic resonance images showed mobile atlantoaxial dislocation with intramedullary heterogeneously enhancing cervicomedullary mass. The patient underwent suboccipital craniectomy with C1-4 laminectomy. Tumor was pinkish grey, tenacious with ill-defined plane and cyst at poles. C1-C2 fusion was done using C1 lateral mass and C2 pars screw and rod system with onlay bone graft. Histopathology revealed pilocytic astrocytoma. At the time of discharge, the patient showed improvement in spasticity. Postoperative lateral radiograph showed reduced atlantoaxial dislocation with stable construct.

Pelvic floor imaging with MR defecography: correlation with gynecologic pelvic organ prolapse quantification.

PURPOSE: Pelvic organ prolapse (POP) is assessed differently by gynecologists and radiologists. It is clinically staged by physical examination using the POP-Q (Pelvic Organ Prolapse Quantification) system and radiologically staged by modalities such as by Magnetic Resonance Defecography (MRD). The purpose of this study was to correlate the two methods of staging pelvic organ prolapse for each pelvic compartment by comparing correlative anatomic points and differences in technique. This understanding will help synthesize information from two different perspectives and bridge the gap between multiple specialists who participate in the care of patients with complex pelvic floor disorders. METHODS: A retrospective single institution study comparison of patients who underwent both dynamic magnetic resonance pelvic floor imaging and pelvic organ prolapse quantification (POP-Q) at our medical center was done. Two urogynecologists performed the POP-Q and one fellowship-trained radiologist interpreted the MRD and both staged pelvic organ prolapse independently. RESULTS: A total of 280 patients underwent magnetic resonance imaging (MRI) of the pelvic floor from 1/2013 to 12/2017, of whom 68 met our inclusion criteria. When compared to POP-Q, MRI has strong, moderate, and weak correlation for quantification of anterior, middle, and posterior compartment prolapse, respectively. POP-Q measurements Aa, Ba, C, and D are analogous to true pelvic anatomical landmarks which are directly and consistently measurable by MRI, hence accounting for the better correlation in anterior and middle compartments when compared to measurements Ap and Bp which do not correlate with true anatomical landmarks, and hence can explain the weak correlation for posterior compartment prolapse. CONCLUSION: When comparing POP-Q to MRI, anterior and middle compartment prolapse have better correlation than posterior compartment prolapse. Inherent differences that exist in technique and anatomic landmarks used for staging pelvic organ prolapse by clinical exam and imaging criteria account for this. MRD, however, still provides anatomic details on static images, real time simultaneous overview of multi-compartmental prolapse, characterizes contents of cul-de-sac hernias and rectal evacuation on dynamic imaging. Corroborative information derived from both methods of staging organ will result in optimum patient care.

Imaging and Management of Rectal Cancer.

High-resolution phased array external magnetic resonance imaging (MRI) is the first investigation of choice in rectal cancer for local staging, both in the primary and restaging situations. Use of MRI helps differentiate between those with good prognosis, which can be offered upfront surgery and the poor prognostic cases where treatment intensification is needed. MRI identified poor prognostic factors are threatened or involved mesorectal fascia, T3 tumors with >5 mm extramural spread, those with extramural vascular invasion, pelvic sidewall nodes and mucinous tumors. At restaging, use of MRI helps evaluate response and an MR tumor regression grading system is being evaluated. Complete response seen on clinical examination and endoscopy, needs confirmation on MRI using both T2-weighted and diffusion-weighted sequences to justify a "watch and wait" approach. In this subset of patients, MRI also plays a role in monitoring and detecting early regrowth. In those with partial response, MRI helps define surgical margins and can be used as a roadmap to decide between sphincter preserving surgeries and radical sphincter sacrificing surgeries; pelvic exenteration and pelvic sidewall lymph node dissection. Poor responders on MRI may benefit from adjuvant chemotherapy. Use of MRI thus helps in individualizing treatment in rectal cancer.

Comprehensive Review of Abdominopelvic Mesenchymal Tumors With Radiologic Pathologic Correlation and Update on Current Treatment Guidelines-Part 2.

Soft-tissue sarcomas are a diverse group of rare mesenchymal malignancies accounting for only 1% of all solid adult malignancies. These have been categorized in 12 broad groups by the World Health Organization (WHO) with their recent update in 2013. Majority of them lack specific imaging features serving as imaging conundrums for a radiologist. These are often large masses at presentation as they are asymptomatic or cause vague clinical symptoms. These tumors are challenging for surgeons as well as they find it difficult to achieve complete resection because of complex intra-abdominal anatomy and their close relationship with critical structures. Often, a multidisciplinary approach is required to decide on the most appropriate management for these complex cases so as to provide optimal patient care. Knowledge of the WHO classification, pathologic features, and treatment options available helps the radiologist make a meaningful contribution in multidisciplinary discussions of such cases and overall patient care. Liposarcoma (well-differentiated and dedifferentiated liposarcomas), leiomyosarcoma, and gastrointestinal stromal tumor are the 3 most common primary intra-abdominal sarcomas. In part 1 of this article, general features of soft-tissue sarcomas and some of the common tumors from WHO category 1-4 found in abdomen and pelvis are discussed. Part 2 will focus on common tumors from remainder of the WHO categories.

Comprehensive Review of Abdominopelvic Mesenchymal Tumors with Radiologic Pathologic Correlation and Update on Current Treatment Guidelines - Part 1.

Soft-tissue sarcomas are a diverse group of rare mesenchymal malignancies accounting for only 1% of all solid adult malignancies. These have been categorized in 12 broad groups by the World Health Organization (WHO) with their recent update in 2013. Majority of them lack specific imaging features serving as imaging conundrums for a radiologist. These are often large masses at presentation as they are asymptomatic or cause vague clinical symptoms. These tumors are challenging for surgeons as well as they find it difficult to achieve complete resection because of complex intra-abdominal anatomy and their close relationship with critical structures. Often, a multidisciplinary approach is required to decide on the most appropriate management for these complex cases so as to provide optimal patient care. Knowledge of the WHO classification, pathologic features and available treatment options will help the radiologist make a meaningful contribution in multidisciplinary discussions of such cases and overall patient care. Liposarcoma (well-differentiated and dedifferentiated liposarcomas), leiomyosarcoma, and gastrointestinal stromal tumor are the 3 most common primary intra-abdominal sarcomas. In part 1 of this article, general features of soft tissue sarcomas and some of the common tumors from WHO category 1-4 found in abdomen and pelvis are discussed. Part 2 will focus on common tumors from remainder of the WHO categories.

MR neurography in Parsonage-Turner syndrome.

BACKGROUND AND AIMS: Parsonage Turner Syndrome is a well known clinical entity. Several excellent articles have succinctly described Magnetic Resonance Imaging (MRI) findings in PTS. However, these articles have inferred neural involvement in PTS based on the patterns of denervation of muscles in the shoulder region. The aim of this study is to directly visualize the distribution and extent of abnormality in MR Neurography (MRN) of the brachial plexus in known cases of brachial plexus neuritis or Parsonage-Turner Syndrome (PTS). METHODS: 15 patients who were diagnosed with PTS based on clinical and electrophysiological findings participated in the study. MRN of the brachial plexus was done in a 1.5T system using a combination of T1W (T1-weighted), T2W (T2-weighted) fat-saturated, STIR (Short Tau Inversion Recovery), 3D STIR SPACE (Sampling Perfection with Application Optimized Contrasts) and 3D T2W SPACE sequences. Findings were recorded and assessed. RESULTS: The age range of our patients was 7-65 years (mean 37.87 years). Most of the patients had unilateral symptoms. All patients had weakness in shoulder abduction. Other common associated complaints included pain in the shoulder/neck/arm and preceding fever. MRN revealed the percentage of involvement of roots, trunks, cords and terminal branches was 53.3%, 46.7%, 40% and 13.3% respectively. Evidence of muscle denervation in the form of edema, fatty infiltration and atrophy was noted in 8 (53.3%) patients. CONCLUSION: Most of the patients in this study had unilateral involvement on MRN. The roots were the commonest site of involvement followed by the trunks, cords and terminal branches. C5 was the most commonly involved root.

A Cadaveric Study of Cutaneous Vascular Anatomy about the Elbow Using Computed Tomography Angiography.

The posterior approach is a commonly employed exposure of the elbow that provides excellent visualization and efficacy for various orthopedic procedures, including total elbow arthroplasty (TEA) and fracture care. The posterior approach to the elbow has been associated with an increased rate of wound complications, including infection, skin necrosis, and wound dehiscence. Despite an association between these complications and decreased elbow perfusion, data regarding the intrinsic anatomic etiology for preferential complications in this area has been scarcely reported in the literature. This study characterizes the subdermal and cutaneous vascular perfusion about the elbow by describing the predominant direction of circulation, subdermal anastomoses, and volume of perfusion through cadaveric modeling using computed tomography angiography (CTA). Fifteen upper extremity cadaver specimens were prepared with injection of radiographic contrast directly into the axillary artery immediately preceding CTA imaging of each specimen. Sectra IDS7 software for Windows was used for analysis of all images to produce superimposed axial and 3-D reconstructions of each CTA series. From these images it was discerned that the predominant direction of flow in the posterior elbow integument is anterior medial to posterior lateral. Both the posterior medial and posterior lateral subdermal vascular networks emanate from proximally derived medial arterial sources with few anastomoses and minimal collateral perfusion from the anterolateral location. Consequently, it is important to preserve medial subdermal vascular structures to prevent ischemic wound complications. This is especially true in previously incised elbow integuments. Clin. Anat. 32:509-514, 2019. © 2019 Wiley Periodicals, Inc.

The Incremental Value of Magnetic Resonance Neurography for the Neurosurgeon: Review of the Literature.

INTRODUCTION: Magnetic resonance neurography (MRN) is a newer imaging technique that is increasingly used for detailed visualization of peripheral nerves not reliably achieved with conventional imaging modalities. Although MRN has been previously characterized in the literature, few studies have assessed its utility to neurosurgery, where there is potentially substantial impact particularly with preoperative assessment. In this article, we performed a retrospective review of cases in which MRN was used for clinical evaluation and surgical decision making. METHODS: MRN, clinical assessment, and operative decision making were retrospectively assessed in 206 consecutive patients at our institution between 2015 and 2018. RESULTS: MRN was determined to lead to a change in diagnosis or surgical decision making in 44 patients (21.4%: 27 female, 17 male). These were classified into 6 major diagnostic categories: trauma, postsurgical evaluation, compressive/degenerative conditions, tumors, neuritis/inflammation, and other neurogenic lesions. Nine representative cases were selected from these categories to highlight the range of neurosurgical pathologies in which MRN was useful in diagnostic assessment and surgical decision making. CONCLUSIONS: MRN is an underused resource with great potential value in the diagnoses, surgical planning, and postoperative assessment of various neurosurgical conditions. These present incremental utility to the neurosurgeon as well as socioeconomic benefit in the detection of potentially surgically treatable lesions.

Medial meniscal extrusion: Detection, evaluation and clinical implications.

The menisci play an important role in knee kinematics. Their unique anatomy allows them to channel forces generated during knee movements through the larger tibio-femoral condylar surfaces while simultaneously resisting deleterious hoop stresses. Although physiologic meniscal extrusion occurs with every knee joint movement, pathologic meniscal extrusion subjects the knee to persistent and excessive load transmission. This renders the knee structures susceptible to injury or exacerbates worsening of existing knee joint internal derangement. Detection and quantification of meniscus extrusion is important given its association with underlying pathological processes and internal derangements such as cartilage loss, osteoarthritis and meniscal tears. The medial and lateral menisci vary in size, attachments and load transmission, and the medial meniscus is more susceptible to injury. In this article, the authors illustrate the role of meniscus kinematics, and the identification and quantification of medial meniscal extrusion. Multimodality imaging appearances and implications of presence of medial meniscal extrusion in different knee joint pathologies are discussed with review of the relevant literature.

Rational design and evaluation of HBsAg polymeric nanoparticles as antigen delivery carriers.

The present work is focused on the development and evaluation of single dose sustained-release Hepatitis B surface antigen (HBsAg) loaded nanovaccine for Hepatitis B. The conventional treatment suffers from repeated administration and hence requires a booster dose. Therefore, polymeric nanovaccine of HBsAg was developed by double emulsion solvent evaporation technique, utilizing central composite design for formulation optimization. The effects of independent variables (like polymer amount, stabilizer concentration, aqueous/organic phase ratio and homogenizer speed) were also studied on critical quality attributes like particle size and entrapment efficiency. Nanovaccine was characterized in terms of physicochemical parameters, release, internalization and in vivo immunological evaluation in BALB/c mice after administration by different routes such as oral, sub-cutaneous, nasal and intramuscular. The designed nanovaccine demonstrated nanometric size with smooth surface, negative zeta potential, maximum entrapment, sustained release and better internalization in macrophage and MRC-5 cell line. The immune-stimulating activity of nanovaccine administered by different routes was evaluated by measuring anti-HBsAg titre like specific immunoglobulin IgG and IgA response and cytokine level (interleukin-2, interferon-Y) measurement. The results indicated that the nanovaccine administered by intramuscular route produced better humoral as well as cellular responses and potential carriers for antigen delivery at single dose administration via intramuscular route.