Hasaam Uldin

Magnetic resonance imaging (MRI) is universally recognized as the gold standard for evaluating anterior cruciate ligament (ACL) injuries. However, differentiating partial tears from complete ruptures using the standard sagittal plane remains a diagnostic challenge. The oblique coronal orientation of the ACL often leads to volume averaging artifacts and inaccurate interpretations. While axial imaging offers a favorable alternative, distal tears near the tibial attachment are frequently missed. This review synthesizes current concepts in the anatomical and radiological evaluation of the ACL and introduces the “Namaste sign,” a novel and proposed preliminary imaging marker observed on coronal MRI to help assess ACL integrity. Grounded in the distinct native double-bundle architecture of the ACL, the Namaste sign utilizes the coronal plane to evaluate the transverse relationship and physiological tension of the anteromedial and posterolateral bundles. In a normal knee, these bundles converge symmetrically from their distinct tibial footprints and maintain tight contact with the lateral femoral condyle, mimicking hands pressed together in a traditional “Namaste” gesture. This article details the anatomical basis of this sign, provides a systematic method for its identification, and illustrates how morphological variations such as “broken hands,” “absent hands,” “absent proximal hug,” or “separation of hands” may correspond to specific ACL lesions. As a preliminary conceptual marker, the Namaste sign is intended to serve as an educational adjunct to combined three-plane evaluation rather than a standalone diagnostic criterion. Notably, this sign is not applicable to postoperative ACL reconstructions. A preliminary pilot study of 50 cases utilizing thin-slice MRI (≤3 mm) demonstrated nearly 100% visibility of the sign, 98% diagnostic accuracy, and almost perfect inter-observer agreement between two radiologists with more than 10 years of experience (Cohen’s kappa = 0.92). However, future diagnostic studies with rigorous arthroscopic reference standards are required to establish its clinical performance and reliability in larger cohorts.

Benign notochordal cell tumours (BNCTs) are non-aggressive intraosseous lesions arising from notochordal remnants within the axial skeleton. This study aimed to evaluate their computed tomography (CT) and magnetic resonance imaging (MRI) features and to define how serial imaging follow-up can be used to monitor these lesions. A retrospective review with institutional ethical approval included all patients diagnosed with spinal BNCTs at a tertiary orthopaedic oncology centre between June 2008 and October 2025. Imaging studies were reviewed by consensus of three fellowship-trained musculoskeletal radiologists. Lesions were assessed using CT and MRI for location, size, margins, presence of concerning features, and interval change on follow-up imaging. Nineteen patients were included (11 females, 8 males; mean age 44.6 years, range 16-66 years). All BNCTs were incidentally discovered, solitary, well-defined, intraosseous lesions located in the midline of the vertebral bodies, without cortical destruction or extraosseous components. Most were sacral (14/19, 73.7%). Mean maximal lesion size was 1.7 cm. On MRI, 18/19 lesions demonstrated homogeneous low-to-intermediate T1-weighted and high T2-weighted/STIR signal intensity. Internal microscopic fat was present in 9/12 cases. On CT, lesions typically presented with faint sclerosis (10/12). Four lesions with atypical imaging features underwent biopsy and were confirmed as BNCTs. Mean imaging follow-up was 34.2 months (range 1 month to 11 years). All lesions remained stable throughout follow-up. Incidental spinal BNCTs demonstrate characteristic non-aggressive CT and MRI features and stability on longitudinal imaging follow-up. Lesions without concerning imaging features can be appropriately managed with interval imaging surveillance.

Background: Myopericytoma is a typically benign, slow-growing soft tissue tumour that originates from pericytes, the contractile cells surrounding blood vessels. While they can appear in both appendicular and axial skeletons, the rarity and indolent nature of the condition can be a clinical challenge. Objective: The purpose of this study is to review the radiological findings of myopericytomas in a series of cases at a tertiary referral centre, identify characteristic imaging patterns and aid in the accurate diagnosis of suspected lesions. Patients and Methods: A retrospective study was conducted and 62 histopathologically proven cases of myopericytoma were identified at our tertiary orthopaedic oncology institution. Of these, 51 cases were included in the final cohort and analysed. Each case was reviewed for patient demographics, lesion morphology and magnetic resonance imaging (MRI) signal characteristics. Results: Of 51 cases, most were located in the subcutaneous soft tissues. All lesions were solitary, with a mean size of 2.06 cm. On imaging, all lesions were isointense to muscle on T1-weighted sequences and hyperintense on fluid-sensitive sequences, exhibiting variable patterns of post-contrast enhancement. No significant signal drop was observed on chemical shift imaging and no diffusion restriction was noted on diffusion-weighted imaging (DWI). Conclusion: Myopericytoma is a rare soft tissue tumour with certain distinctive imaging features which can aid in early recognition and accurate diagnosis.

Objectives: Direct Magnetic Resonance Arthrography (MRA) is widely used for joint distension to assess intra-articular structures. Gadolinium based contrast agents (GdCA) have been used widely but concerns have emerged regarding their safety and cost. This study assesses current practice of UK musculoskeletal radiologists within the context of these recent changes. Methods: A questionnaire was disseminated to members of the British Society of Skeletal Radiology. This assessed whether responders performed MRA and—if so—investigated the techniques used. Responses were aggregated and compared to those from a comparator study from 2019. Results: Of 45 survey respondents, 43 regularly perform direct MRA with 24 (56%) doing over three a month. Of the 43, 72% use gadolinium with 11 using a licenced preparation and 19 using an off-licence preparation. Twelve respondents (28%) used saline instead of gadolinium. Many respondents had recently changed their practice, most commonly due to logistics (15 respondents - 33%) with concerns over bioaccumulation (14 respondents) a close second. Financial cost and environmental impact concerns were less common. Additional comments highlighted the impact of Magnevist discontinuation and improvements in conventional MRI. Conclusions: Although MRA remains prevalent, practice has changed for various reasons with a notable reduction in GdCA use. These considerations and alternatives to GdCA-MRA are discussed with reference to the existing literature and our tertiary centre experience. Advances in knowledge: This study outlines the evolving state of MRA use by radiologists across the UK and discusses options to optimise safety in its use, particularly referencing GdCA use.

Background and Aims: To establish the role of imaging in the diagnosis, staging, treatment planning, and surveillance of musculoskeletal tumours in orthopaedic oncology. Methods: A thorough literature search was carried out into the applications of conventional radiography, ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI), and nuclear medicine techniques. The strengths, limitations, and complementary contributions of each modality were reviewed in relation to diagnosis, staging, biopsy guidance, treatment response assessment, and surveillance. Results: A multidisciplinary approach—integrating clinicopathological assessment with multimodality imaging, maximises diagnostic accuracy and guides patient-specific management. Radiography remains the first-line investigation, offering initial lesion characterisation and narrowing the differential. US provides high-resolution evaluation of superficial soft tissue lesions and enables real-time image-guided biopsy. CT offers superior depiction of cortical integrity, osseous destruction, and matrix mineralisation, with advanced dual-energy techniques improving material characterisation and reducing metal artefacts. MRI is the gold standard for local staging, with advanced sequences such as diffusion-weighted imaging, dynamic contrast-enhanced MRI, and chemical shift imaging enhancing lesion characterisation and treatment response assessment. Established and emerging nuclear medicine techniques provide complementary functional information, enabling early detection of metastases and metabolic treatment response evaluation. Conclusion: This review outlines the strengths, limitations, and complementary contributions of these modalities in optimising the diagnostic and treatment pathways for orthopaedic oncology patients. It therefore highlights how imaging in orthopaedic oncology is inherently multimodal, with each modality contributing unique and complementary diagnostic insights.