Upper extremity compartmental anatomy: clinical relevance to radiologists

Biological Sample Collection to Advance Research and Treatment: A Fight Osteosarcoma Through European Research and Euro Ewing Consortium Statement

Osteosarcoma and Ewing sarcoma are bone tumors mostly diagnosed in children, adolescents, and young adults. Despite multimodal therapy, morbidity is high and survival rates remain low, especially in the metastatic disease setting. Trials investigating targeted therapies and immunotherapies have not been groundbreaking. Better understanding of biological subgroups, the role of the tumor immune microenvironment, factors that promote metastasis, and clinical biomarkers of prognosis and drug response are required to make progress. A prerequisite to achieve desired success is a thorough, systematic, and clinically linked biological analysis of patient samples, but disease rarity and tissue processing challenges such as logistics and infrastructure have contributed to a lack of relevant samples for clinical care and research. There is a need for a Europe-wide framework to be implemented for the adequate and minimal sampling, processing, storage, and analysis of patient samples. Two international panels of scientists, clinicians, and patient and parent advocates have formed the Fight Osteosarcoma Through European Research consortium and the Euro Ewing Consortium. The consortia shared their expertise and institutional practices to formulate new guidelines. We report new reference standards for adequate and minimally required sampling (time points, diagnostic samples, and liquid biopsy tubes), handling, and biobanking to enable advanced biological studies in bone sarcoma. We describe standards for analysis and annotation to drive collaboration and data harmonization with practical, legal, and ethical considerations. This position paper provides comprehensive guidelines that should become the new standards of care that will accelerate scientific progress, promote collaboration, and improve outcomes.

The Investigation of Bio-impedance Analysis at a Wrist Phantom with Two Pulsatile Arteries

PURPOSE

Bio-impedance analysis (BIA) has been widely investigated for hemodynamic monitoring. However, previous works rarely modelled two synchronously pulsatile arteries (representing the radial and ulnar arteries) in the wrist/forearm model. This work aims to clarify and quantify the influences of two pulsatile arteries on BIA.

METHODS

First, two blood-filled arteries were structured in a 3D wrist segment using the finite element method (FEM). Afterwards, an easy-to-produce two-arteries artificial wrist was fabricated with two components: gelatine-based surrounding tissue phantom and saline blood phantom. A syringe driver was utilised to constrict the arteries, and the impedance signals were measured using a Multi-frequency Impedance Analyser (MFIA).

RESULTS

Both simulation and experimental results demonstrated the non-negligible influences of the ulnar artery on the overall BIA, inducing unwanted resistance changes to the acquired signals from the radial artery. The phantom experiments revealed the summation of the individual resistance changes caused by a single pulsatile artery was approximately equal to the measured resistance change caused by two synchronously pulsatile arteries, confirming the measured impedance signal at the wrist contains the pulsatile information from both arteries.

CONCLUSION

This work is the first simulation and phantom investigation into two synchronously pulsatile arteries under BIA in the distal forearm, providing a better insight and understanding in the morphology of measured impedance signals. Future research can accordingly select either a small spacing 4-spot electrode configuration for a single artery sensing or a band electrode configuration for overall pulsatile arteries sensing. A more accurate estimation of blood volume change and pulse wave analysis (PWA) could help to develop cuffless blood pressure measurement (BPM).

A Pilot Study Examining the Dielectric Response of Human Forearm Tissues

This work aims to describe the dielectric behaviors of four main tissues in the human forearm using mathematical modelling, including fat, muscle, blood and bone. Multi-frequency bioimpedance analysis (MF-BIA) was initially performed using the finite element method (FEM) with a 3D forearm model to estimate impedance spectra from 10 kHz to 1 MHz, followed by a pilot study involving two healthy subjects to characterize the response of actual forearm tissues from 1 kHz to 349 kHz. Both the simulation and experimental results were fitted to a single-dispersion Cole model (SDCM) and a multi-dispersion Cole model (MDCM) to determine the Cole parameters for each tissue. Cole-type responses of both simulated and actual human forearms were observed. A paired t-test based on the root mean squared error (RMSE) values indicated that both Cole models performed comparably in fitting both simulated and measured bioimpedance data. However, MDCM exhibited higher accuracy, with a correlation coefficient (R2) of 0.99 and 0.89, RMSE of 0.22 Ω and 0.56 Ω, mean difference (mean ± standard deviation) of 0.00 ± 0.23 Ω and -0.28 ± 0.23 Ω, and mean absolute error (MAE) of 0.0007 Ω and 0.2789 Ω for the real part and imaginary part of impedance, respectively. Determining the electrical response of multi-tissues can be helpful in developing physiological monitoring of an organ or a section of the human body through MF-BIA and hemodynamic monitoring by filtering out the impedance contributions from the surrounding tissues to blood-flow-induced impedance variations.

The effects of tissue proportions on blood volume change-induced variations using bio-impedance analysis: a simulation study. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023;2023:1-4. [PMID: 38082597 DOI: 10.1109/embc40787.2023.10340562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Bioimpedance Analysis (BIA) along the radial artery has been widely investigated for hemodynamic monitoring. However, its applicability to different body type populations still lacks sufficient research. The Finite Element Method (FEM) was performed on three different wrist models using ANSYS HFSS, aiming to reveal the influences of different fat and muscle proportions on the sensitivity of blood volume change-induced bioimpedance change. The simulation results confirmed that the current density in each tissue mainly depended on the conductivity of tissues. The higher conductivity of the tissue, the higher current density inside said tissue. The amounts of flowing current were decided by both volume and conductivity of tissues. Moreover, increasing the fat layer thickness from 4 mm to 6 mm raised simulated impedance from 86.82 Ω to 100.39 Ω and impedance change from 0.63 Ω to 1.55 Ω. However, a higher muscle proportion occupied more injected current from the blood and resulted in lower impedance change. Therefore, for the overweight population, the placement of BIA is recommended to avoid the muscular body parts for the acquirement of better-quality pulse waves.Clinical Relevance-This establishes the bio-impedance analysis should avoid the muscular body parts for a better blood pulse wave quality for overweight populations.

Towards Estimating Arterial Diameter Using Bioimpedance Spectroscopy: A Computational Simulation and Tissue Phantom Analysis

This paper improves the accuracy of quantification in the arterial diameter-dependent impedance variance by altering the electrode configuration. The finite element analysis was implemented with a 3D human wrist fragment using ANSYS Electronics Desktop, containing fat, muscle, and a blood-filled radial artery. Then, the skin layer and bones were stepwise added, helping to understand the dielectric response of multi-tissues and blood flow from 1 kHz to 1 MHz, the current distribution throughout the wrist, and the optimisation of electrode configurations for arterial pulse sensing. Moreover, a low-cost wrist phantom was fabricated, containing two components: the surrounding tissue simulant (20 wt % gelatine power and 0.017 M sodium chloride (NaCl) solution) and the blood simulant (0.08 M NaCl solution). The blood-filled artery was constricted using a desktop injection pump, and the impedance change was measured by the Multi-frequency Impedance Analyser (MFIA). The simulation revealed the promising capabilities of band electrodes to generate a more uniform current distribution than the traditional spot electrodes. Both simulation and phantom experimental results indicated that a longer spacing between current-carrying (CC) electrodes with shorter spacing between pick-up (PU) electrodes in the middle could sense a more uniform electric field, engendering a more accurate arterial diameter estimation. This work provided an improved electrode configuration for more accurate arterial diameter estimation from the numerical simulation and tissue phantom perspectives.

Anatomy of the nerves, vessels, and muscular compartments of the forearm, as revealed by high-resolution ultrasound. Part 1: overall structure and forearm compartments

In recent decades, high-resolution ultrasound (HRUS) has revolutionized the morphological and structural evaluation of peripheral nerves and muscles, revealing details of the internal structure of the neural fascicles and muscle architecture. Applications range from diagnostics to interventional procedures. The anatomy of the forearm region is complex, with several muscles and an extensive network of vessels and nerves. To guarantee the success of the evaluation by HRUS, knowledge of the normal anatomy of the region is essential. The aim of these two companion articles is to present the normal anatomy of the nerves and compartments of the forearm, as revealed by HRUS, as well as the relationships between the main vessels and nerves of the region. Part 1 aims to review the overall structure of nerves, muscles and tendons, as seen on HRUS, and that of the forearm compartments. We present a practical approach, with general guidelines and tips on how best to perform the study. Part 2 is a pictorial essay about compartment vascularization and cutaneous innervation. Knowledge of the normal anatomy of the forearm improves the technical quality of the examinations, contributing to better diagnoses, as well as improving the performance and safety of interventional procedures.

Tricks and pitfalls in the surgical treatment of malignant bone tumours of the forearm in children and adolescents

Malignant bone tumours around the forearm are rare. Nowadays, oncological and surgical management of bone sarcomas of this region has improved significantly. Although the anatomical features are complex, limb-sparing surgery is possible with wide surgical resection. Biological reconstruction methods are promising in this anatomically unique region. In addition, meticulous soft-tissue reconstruction yields good functional results in the hand and wrist. This study reviews malignant bone tumours of the forearm and their oncological and surgical management. Malignant bone tumours should be treated with a multidisciplinary approach based on chemotherapy, radiotherapy and limb salvage procedures.

Staging and Classification of Primary Musculoskeletal Bone and Soft Tissue Tumors Based on the 2020 WHO Update, From the AJR Special Series on Cancer Staging

Staging of primary musculoskeletal bone and soft tissue tumors is most commonly performed using the AJCC and the Enneking or Musculoskeletal Tumor Society (MSTS) staging systems. Radiologic imaging is integral in achieving adequate musculoskeletal neoplastic staging by defining lesion extent and identifying regional lymph node involvement and distant metastatic disease. Additional important features in surgical planning, though not distinct components of the staging systems, include cortical involvement, joint invasion, and neurovascular encasement; these features are optimally evaluated by MRI. In 2020, the WHO updated the classification of primary musculoskeletal tumors of soft tissue and bone. The update reflects the continued explosion in identification of novel gene alterations in many bone and soft tissue neoplasms. This has resulted in newly designated lesions, reclassification of lesion categories, and improved specificity of diagnosis. While radiologists do not need to have a comprehensive knowledge of the pathologic details, a broad working understanding of the most recent update is important to aid accurate and timely diagnosis given that histologic grading is a component of all staging systems. By approaching primary musculoskeletal neoplasms through a multidisciplinary approach with colleagues in pathology, orthopedic oncology, radiation oncology, and medical oncology, radiologists may promote improved diagnosis, treatment, and outcomes.

MRI of myositis and other urgent muscle-related disorders

Myositis has many etiologies, and it can be encountered in the acute or chronic setting. Our goal is to increase the radiologist’s knowledge of myositis and other urgent muscle disorders encountered in the emergent or urgent setting. We review the clinical presentation, the MRI appearance, and the complications that can be associated with these entities. Since myositis can affect multiple muscle compartments, we review how to differentiate the compartments of the appendicular skeletal in order to generate reports that relay important anatomic information to the treating physician. Given the poor sensitivity and positive predictive value of the clinical signs and symptoms used to diagnosing acute compartment syndrome, we discuss the potential use of MRI in cases of suspected but clinically equivocal compartment syndrome in the future.

Imaging of the lesions in the lateral muscle compartment of the forearm, alias mobile wad of Henry: Demographics, radiological anatomy and surgical relevance

INTRODUCTION

Mobile wad of Henry (MOH) is a preferred surgical term used to describe the lateral compartment muscles of the forearm consisting of brachioradialis, extensor carpi radialis longus and brevis. The lesions in this compartment are uncommon. In this paper, we describe the largest series of the MOH lesions including their demographics, imaging appearances and importance of surgical anatomy whilst managing MOH lesions via radiological or surgical interventions.

METHODS

A retrospective search of oncology database for lesions in MOH at our tertiary orthopaedic oncology institute was performed for the last 12 years (2007-2019) after obtaining institutional review board approval. We further analyse data to obtain further clarity of various neoplasms occurring at this particular anatomical site.

RESULTS

We identified 28 patients with MOH lesions with an age range of 8 to 84 years and a male predominance. Imaging-wise, majority of lesions were benign following characteristics of lipomatous tumours, lipomas being the commonest. Other relatively uncommon benign lesions were nodular fasciitis, myositis ossificans and brachioradialis muscle injury; whereas aggressive MOH soft tissue neoplasms included synovial sarcoma and fibrohistiocytoma.

CONCLUSION

Although majority of MOH lesions are benign, one needs to be aware of spectrum containing uncommon benign and aggressive MOH lesions. When posed with dilemma, the MOH lesions require multidisciplinary approach with close collaboration of the radiologist, the surgeon and the pathologist to decide further management.

Bone Biopsies: What Radiologists Need to Know

OBJECTIVE. The purpose of this article is to provide a step-by-step guide for bone imaging-guided percutaneous core needle biopsy, including the armamentarium available and the most recent advances. CONCLUSION. Bone imaging-guided percutaneous core needle biopsies are well-established, minimally invasive, cost-effective interventions for histologic characterization of bone lesions with an excellent safety profile and diagnostic outcomes; they play a crucial role in management of patients. Radiologists involved in the care of patients with bone lesions must be familiar with the various steps involved in such procedures and their role in patient management.

Bone and Soft-Tissue Biopsies: What You Need to Know

Percutaneous, image-guided musculoskeletal biopsy, due to its minimal invasive nature, when compared with open surgical biopsy, is a safe and effective technique which is widely used in many institutions as the primary method to acquire tissue and bone samples. Indications include histopathologic and molecular assessment of a musculoskeletal lesion, exclusion of malignancy in a bone/vertebral fracture, examination of bone marrow, and infection investigation. Preprocedural workup should include both imaging (for lesion assessment and staging) and laboratory (including coagulation tests and platelet count) studies. In selected cases, antibiotic prophylaxis should be administered before the biopsy. Core needle biopsy of musculoskeletal lesions has a diagnostic accuracy that ranges from 66 to 98% with higher diagnostic yield for lytic, large-size, malignant lesions and when multiple and long specimens are obtained. Reported complication rates range between 0 and 10% and usually do not exceed 5%, with a suggested threshold of 2%. The purpose of this review article is to illustrate the technical aspects, the indications, and the methodology of percutaneous image-guided bone biopsy that will assist the interventional radiologist to perform these minimal invasive techniques.

Assessment of normal forearm compartment pressures in a Nigerian population

PURPOSE

The forearm is prone to raised compartment pressure and it is the second most common site for compartment syndrome. The normal compartment pressure of the forearm should be known and serve as a benchmark for the diagnosis of acute and chronic compartment syndrome. This study was aimed to determine the normal compartment pressures of the forearm using a digital compartment pressure monitor.

METHODS

This was a prospective hospital-based study of the uninjured forearm in 30 patients, who presented with closed unilateral forearm fracture at the accident and emergency department of a tertiary health care facility, between June 2012 and December 2013. Approval was sought and obtained from institutions ethical committee. An 18 gauge bevelled-tip needle, attached to a Compass TM digital compartment pressure monitor made by Mirador USA, was used to measure the pressures in the compartments of the forearm. Data obtained were analysed using the Stata 12. Significance was determined at p < 0.05.

RESULTS

The mean age was 38.3 ± 18.3 years with male-to-female ratio of 2.3:1. The pressures in the volar compartment of the forearm ranged from 1 to 8 mmHg with a mean ± SD compartment pressure of 4.7 ± 1.5 mmHg. In the dorsal compartment the pressure ranged from 2 to 8 mmHg with a mean ± SD of 4.9 ± 1.7 mmHg SD, while the lateral compartment measurement ranged between 1 and 5 mmHg with a mean ± SD of 3.6 ± 1.1 mmHg. There was significant positive correlation (p < 0.01) between the compartment pressures in the volar, dorsal, and lateral compartments.

CONCLUSION

The normal compartment pressure for forearm is 4.4 ± 1.6 mmHg and ranged from 1 to 8 mmHg from this study in our environment. This will serve as reference value when forearm compartment pressure is being measured.

Practical Guidelines for Ultrasound-Guided Core Needle Biopsy of Soft-Tissue Lesions: Transformation from Beginner to Specialist

Ultrasound-guided core needle biopsy (US-CNB) is an important step in the diagnosis of musculoskeletal soft-tissue lesions. To maximize efficacy and minimize the complications of US-CNB, it is critical to collaborate with a multidisciplinary team and to understand the particular considerations of US-CNB for these lesions. The purpose of this article is to provide a systematic review and step-by-step tips for using US-CNB to diagnose musculoskeletal soft-tissue lesions.

Focal hand lesions: review and radiological approach

Focal hand lesions are commonly encountered in clinical practice and are often benign. Magnetic resonance (MR) imaging is the imaging modality of choice in evaluating these lesions as it can accurately determine the nature of the lesion, enhancement pattern and exact location in relation to surrounding tissues. However, while MR features of various soft tissue lesions in the hand have been well described, it is often still difficult to differentiate between benign and malignant lesions. We review the MR imaging features of a variety of focal hand lesions presenting at our institution and propose a classification into "benign", "intermediate grade" (histologically benign but locally aggressive with potential for recurrence) and frankly "malignant" lesions based on MR findings. This aims to narrow down differential diagnoses and helps in further management of the lesion, preoperative planning and, in cases of primary malignancy, local staging. Teaching Points • Hand lesions are often benign and MR is essential as part of the workup. • MR features of various hand lesions are well described but are often non-specific. • Certain MR features may help for the diagnosis but histological examination is usually required. • We aim to classify hand lesions based on MR features such as margin, enhancement and bony involvement. • Classifying these lesions can help narrow down differential diagnoses and aid management.

Image-guided musculoskeletal biopsies

Image-guided musculoskeletal (MSK) biopsies are safe and effective procedures that yield diagnostic accuracies up to 97%. When performed in conjunction with a multidisciplinary team, they provide crucial information that will affect patient care and outcome. Computed tomography and ultrasound are the main modalities used to carry out MSK biopsies, and various needles and techniques are available to help the radiologist perform these procedures safely.

Accuracy of CT-guided percutaneous core needle biopsy for assessment of pediatric musculoskeletal lesions

BACKGROUND

CT-guided percutaneous core needle biopsy has been shown in adults to be an effective diagnostic tool for a large number of musculoskeletal malignancies.

OBJECTIVE

To characterize our experience with CT-guided percutaneous core needle biopsy of pediatric bone lesions and determine its utility in diagnosing pediatric osseous lesions, in a population where such lesions are commonly benign.

MATERIALS AND METHODS

From 2000 to 2009, 61 children underwent 63 CT-guided percutaneous biopsies. Radiological, pathological and clinical records were reviewed.

RESULTS

Fourteen biopsies (22%) were performed on malignant lesions, while 49 biopsies (78%) were performed on benign lesions. Forty-nine of the 63 biopsies (78%) were adequate; these children underwent no further tissue sampling. Fourteen of the 63 biopsies (22%) were inadequate or non-conclusive. Of these patients, 12 underwent open biopsy. Retrospective analysis of percutaneous biopsies in these patients demonstrates that 9/12 provided clinically relevant information, and 4/12 patients received final diagnoses that confirmed initial core biopsy findings. No malignancies were diagnosed as benign on percutaneous biopsy. Overall, percutaneous core needle biopsy provided accurate diagnostic information in 84% (53/63) of biopsies.

CONCLUSION

Our results demonstrate that CT-guided percutaneous biopsy is safe and beneficial in children. This study supports the use of CT-guided percutaneous core needle biopsy for primary diagnosis of pediatric bone lesions.

Modeling of the spread of infection in the interdigital spaces of the manus in limbs from clinically normal dogs

OBJECTIVE

To determine whether the pattern of extension of modeled infection from the interdigital web spaces in dogs is predictable and whether the distribution differs among initial injury sites.

SAMPLE POPULATION

Thawed frozen forelimbs from 23 cadavers of previously healthy adult medium- to large-breed dogs.

PROCEDURES

The manus of each forelimb was evaluated by use of computed tomography (CT) before and after injection of radiopaque blue-staining contrast medium into the interdigital web spaces. Two veterinary radiologists reviewed the CT images and recorded the extent of contrast medium from each site. Each manus was dissected or sectioned transversely after imaging, and the extent of contrast medium accumulation was recorded and compared with locations of CT contrast enhancement. The Fisher exact test was performed to determine whether the pattern of contrast medium extension differed by injection site.

RESULTS

Injections made in the interdigital web spaces of the canine manus led to unique and predictable patterns of extension into the surrounding soft tissues. That pattern of extension primarily involved the soft tissues of the digits.

CONCLUSIONS AND CLINICAL RELEVANCE

In humans, knowledge of common extension patterns from infected soft tissue spaces is used to predict the spread of disease within the hand and develop surgical plans that will minimize patient illness. Identification of the common sites of disease spread from the interdigital web spaces in dogs may help improve surgical planning and treatment for infection in the manus.

Computed tomographic and cross-sectional anatomic characterization of myofascial compartments and soft tissue spaces in the manus in cadavers of dogs without forelimb disease

OBJECTIVE

To characterize the computed tomographic (CT) and cross-sectional anatomic features of myofascial compartments and soft tissue spaces in the manus of cadavers of dogs without forelimb disease.

ANIMALS

33 cadavers of adult medium- to large-breed dogs without forelimb disease.

PROCEDURES

Forelimbs were removed from the cadavers within 4 hours after euthanasia or within 6 hours after thawing from initial freezing. Specimens were then frozen for variable periods and thawed for approximately 16 hours before use. Each manus of 60 forelimbs underwent CT before and after injection of a radiopaque, blue-staining contrast medium into locations where soft tissue spaces and myofascial compartments were predicted (on the basis of pilot study data [6 forelimbs]). Two veterinary radiologists reviewed CT images and recorded the presence or absence of a discrete space or compartment at each injection site. Each manus was subsequently dissected or sectioned transversely. Locations of blue-staining contrast medium accumulation were compared with locations of contrast enhancement in CT images. Anatomic structures within each soft tissue space or myofascial compartment were described.

RESULTS

13 soft tissue spaces and 5 myofascial compartments were identified in the manus. Three myofascial structures that were examined were determined not to be compartments.

CONCLUSIONS AND CLINICAL RELEVANCE

Knowledge of soft tissue spaces and myofascial compartments are used to map the likely spread of disease in the hands and feet of humans. Thus, understanding the locations and extent of similar structures in the canine manus may improve the effectiveness of surgical interventions in dogs with injury or inflammation of this region of the forelimb.

Image-guided musculoskeletal biopsy

Image guidance allows safe passage of needles, often into small and otherwise inaccessible lesions, and into the portions of the lesion most likely to yield useful samples, while avoiding damage to important structures. This article hopes to provide a useful guide to image-guided musculoskeletal biopsy for radiologists in practice and in training.