The use of the flow-void sign on MRI: highly sensitive sign in detecting bone metastases from renal cell carcinoma.

OBJECTIVE: To evaluate a range of pathologically proven malignant bone tumours, including primary bone sarcoma and metastatic bone lesions, referred to a tertiary referral centre for the presence of the flow-void sign on MR imaging. MATERIALS AND METHODS: A retrospective search was performed using the radiology information system and oncology database in our institution to identify patients over the age of 40 years referred with a solitary bone lesion. Patients with a range of pathologically proven malignant bone tumours, including primary bone tumours and metastatic bone lesions, were included in the study. MRI images were reviewed for the presence of the flow-void sign. The presence and type of the flow-void sign were correlated with lesion size. RESULTS: Two hundred and sixty-six cases were included in the study. Overall, the flow-void sign was identified in 40.9% of cases. The flow-void sign was most frequently seen in renal cell carcinoma metastasis (90.0%). The sign is highly sensitive (90%) for renal cell carcinoma metastases with a high negative predictive value (98.09%). When the flow-void sign is identified, the lesion is almost three times more likely to represent a renal cell carcinoma metastasis than any other malignant tumour in patients over the age of 40 years with a solitary bone lesion. CONCLUSION: The flow-void sign is highly sensitive for renal cell carcinoma bone metastases and could negate the need for biopsy in patients with a known history of renal cell carcinoma or in whom an occult renal cell carcinoma is subsequently identified.

A Rare Case of Migration of Hyaluronic Acid Gluteal Injection to the Medial Thigh Presenting as a Soft Lump.

Introduction Hyaluronic acid (HA) is a widely accepted agent most commonly used as a dermal filler in facial aesthetic/cosmetic medicine. More recently, HA has been utilized for gluteal augmentation. The common side effects of HA injection are often minor and self-limiting. HA migration is a very rare complication. Case Report We describe a rare case of HA buttock injection migration in a transgender patient, appearing as a superficial lump on right thigh representing a diagnostic dilemma. We highlight the need of a clinical suspicion and discuss the appropriate investigations for guided management of such patients. Conclusion It is essential for reporting radiologist to be aware of the commonly used injectable fillers, their complications, and imaging findings to avoid misdiagnosis and guide optimal patient management.

Optimisation of imaging parameters during CT guided interventional procedures in patients with total hip arthroplasty.

Objective: To determine the optimal KV and mAs settings during CT guided injections in the presence of a total hip arthroplasty so that image quality is maintained whist keeping the dose as low as reasonably achievable. Methods: A total hip arthroplasty phantom with needles with differing gauges was scanned using different CT parameters (from low dose to high dose) and evaluating if this had any effect on needle conspicuity. Conspicuity was graded from 1 to 3 by 2 independent blinded reviewers. Results: Irrespective of the CT settings used (high dose or low dose parameters) needle conspicuity was not adversely affected by the THA for either scorer, therefore a kVp of 100 mA and a. In addition the needle gauge did not affect the conspicuity of the needle. Conclusion: CT guided injections in this total hip arthroplasty phantom model can be performed without any adverse effect on the conspicuity of the needle tip on low dose CT settings. Advancement in knowledge: This paper enables one to optimise the kV and mA while performing interventional procedures.

The changing face of central chondrosarcoma of bone. One UK-based orthopaedic oncology unit's experience of 33 years referrals.

AIM: To ascertain the changing incidence over time of the three commonest primary sarcomas of bone. Data obtained with particular reference to central chondrosarcoma from the annual referral rate to a large UK-based specialist orthopaedic oncology unit. To discuss how the "barnyard pen" analogy of cancers previously applied to certain commoner cancers can also be applicable to central chondrosarcoma (CS) of bone. MATERIALS AND METHODS: A retrospective review was conducted of a computerised database identifying all central cartilage tumours (CCT) of bone, including enchondroma and CS subtypes, between 1985 and 2018. These were compared with the referrals of the other two commonest primary sarcomas of bone, osteosarcoma and Ewing sarcoma. RESULTS: There was a total of 1507 CS showing a 68% overall increase in annual referral rate/incidence over the study period. 68% cases were the borderline malignant lesions now known as atypical cartilaginous tumour (ACT). The annual referral rate/incidence of this entity increased by 194% over the 30 years. Whereas, the annual referral rate/incidence for osteosarcoma and Ewing sarcoma was static for the past 20 years. CONCLUSION: The annual incidence of central CS of bone showed a marked increase over the 33-year period as compared with both osteosarcoma and Ewing sarcoma. This is especially in the ACT category and is thought to be due to the increased provision of MRI scanning flagging up a rise in incidental findings. The spectrum of CCTs from benign to highly malignant elegantly fits the "barn yard" pen analogy and could prove useful as an explanatory tool for patients and clinicians unfamiliar with these diseases.

Skull Imaging-Radiographs and CT revisited.

Although rare, skull vault lesions include a vast array of pathology encompassing infection, benign, and malignant bone tumors. Given the large range of potential diagnoses, it is crucial to identify imaging features to differentiate one from another, ensuring early diagnosis. Radiographs are still valuable in modern radiology but have largely been superseded by computed tomography (CT) due to its high spatial resolution. Both are especially important in developing countries where access to magnetic resonance imaging (MRI) may be limited.There are currently several publications outlining imaging appearances of skull vault lesions. However, the majority of literature is dated, with the last dedicated textbook published in 1980 (Principles of X-ray diagnosis of the skull). Despite overlapping features, a few lesions have "aunt minnie," type classical characteristics, which we will highlight. Most vault lesions also appear as a spectrum depending on location and the exact stage of the disease. A small subset within each disease entity also has atypical features not widely discussed in the current literature. In this pictorial review, we hope to focus on radiographic and CT imaging appearances to help differentiate between various skull vault lesions.

The use of pelvic radiographs as a predictor for gluteal tendinopathy and bursitis.

AIM: To evaluate the relationship between radiographic measurements of the hip and sonographic evidence of gluteal tendinopathy and bursitis in patients with lateral hip pain. METHODS AND MATERIALS: Patients with lateral hip pain referred for ultrasound of the hip in our institution over a 5-year period were identified. Findings of gluteal tendinopathy and subgluteal or trochanteric bursitis on ultrasound were recorded. Radiographs of the hip were also evaluated and femoral offset (FO), global offset (GO), abductor lever arm (ALA) and trochanteric impingement distance (TID) were recorded. The mean of each measurement was compared between patients with gluteal tendinopathy and subgluteal or trochanteric bursitis. RESULTS: 273 patients were included in the study. 107 patients (39.2%) had a THA. In the asymptomatic hip, a range of normal measurements were obtained: FO 22.4-76.5 mm, GO 40.1-116.1 mm, ALA 45.0-98.4 mm and TID 13.8-63.1 mm. In the native hip and post THA, there was no statistically significant relationship between FO, GO, ALA and TID in patients with gluteal tendinopathy or trochanteric or subgluteal bursitis. CONCLUSIONS: Lateral hip pain is a common presenting complaint in patients with hip pain and is reported in a small proportion of patients post THA. No statistically significant relationship was found between radiographic measurements and ultrasound findings in our patient cohort. However, we describe the range of measurements obtained from the normal asymptomatic hip in this large cohort of patients, which may aid in the evaluation and management of patients with lateral hip pain.

Musculoskeletal Corticosteroid Administration: Current Concepts.

Numerous corticosteroid preparations are available, but the type and dose administered is frequently at the discretion of the clinician. This is often based on anecdotal evidence and experience rather than formal clinical guidelines. In order to better understand current practice, we anonymously surveyed 100 members of the British Society of Skeletal Radiologists. The results of the survey demonstrated the arbitrary use of all types of steroid preparation at different anatomical locations. In this article, we review the commonly used corticosteroids and propose a guideline to help practitioners decide on the type and dose of steroid depending on the treatment location.

The impact of age and sex on the diagnosis of intrinsic rectus femoris masses: A single centre experience.

Various pathologies may affect the rectus femoris manifesting as an enlargement of the muscle belly. These include traumatic, inflammatory and neoplastic conditions. We did a retrospective study to provide simple guidelines that will serve as an aid for the clinician in order to diagnose lesions presenting as a mass in the rectus femoris. 81 patients with rectus femoris mass referred to tertiary oncology centre were included in the study. The most common lesions were traumatic and benign tumours. In males, traumatic was commonest (90%) and in female over 40 years, 60% were benign and traumatic.

Metal-on-Metal Total Hip Arthroplasty Associated with Adverse Local Tissue Reaction and Pseudoaneurysm of the Superior Gluteal Artery: A Case Report and Literature Review.

Adverse local tissue reaction (ALTR) and pseudoaneurysm formation are rare but known complications following metal-on-metal hip total hip arthroplasty (THA). We report the first known case in the English literature of a concurrent unilateral ALTR and pseudoaneurysm of the superior gluteal artery in the same patient. Following minimal rise in serum metal ions, an ultrasound of the right hip demonstrated an avascular solid/cystic lesion anterolaterally in keeping with an ALTR. More posterolaterally, a second discrete thick-walled cystic lesion was identified. Doppler interrogation demonstrated a "yin yang" pattern suggestive of a pseudoaneurysm. Magnetic resonance imaging confirmed the presence of an anterolateral periarticular lesion with a second discrete lesion within the gluteus medius. Subsequent computed tomography angiography confirmed the presence of arterial contrast blush within the posterior gluteal lesion adjacent to the superior gluteal artery. The patient remains asymptomatic and is being managed conservatively. We review the imaging characteristics of ALTR and pseudoaneurysm occurring post-THA. When a complex solid/cystic lesion is encountered in a patient with a THA, radiologists must ensure that the lesion is interrogated with color Doppler to confidently distinguish a pseudotumor from a pseudoaneurysm. This information is vital to the surgeon to avoid unexpected hemorrhage if revision joint replacement surgery is being contemplated.

Musculoskeletal imaging: current and future trends.

Advances in imaging technology and the increasing role of interventional procedures in musculoskeletal imaging have continued to stimulate research over recent years. This review summarises some recent articles on musculoskeletal radiology topics and looks forward to potential future developments in this exciting sub-speciality.

Soft tissue tumors with muscle differentiation.

The working group of the World Health Organization (WHO) updated its classification of soft tissue and bone tumors in 2002, and modifications were made primarily to the nomenclature for soft tissue neoplasms. This review presents the imaging features, patient demographics, and clinicopathological findings for benign and malignant skeletal and smooth muscle tumors using the current WHO classification system.

The diagnostic accuracy of MR imaging in osteoid osteoma.

OBJECTIVE: To analyse the MR imaging appearances of a large series of osteoid osteomas, to assess the ability of MR imaging to detect the tumour, and to identify potential reasons for misdiagnosis. DESIGN AND PATIENTS: The MR imaging findings of 43 patients with osteoid osteoma were reviewed retrospectively and then compared with other imaging modalities to assess the accuracy of MR localisation and interpretation. RESULTS: The potential for a missed diagnosis was 35% based solely on the MR investigations. This included six tumours which were not seen and nine which were poorly visualised. The major determinants of the diagnostic accuracy of MR imaging were the MR technique, skeletal location, and preliminary radiographic appearances. There was a wide spectrum of MR signal appearances of the lesion. The tumour was identified in 65% of sequences performed in the axial plane. The nidus was present in only one slice of the optimal sequence in 27 patients. Reactive bone changes were present in 33 and soft tissue changes in 37 patients. CONCLUSION: Reliance on MR imaging alone may lead to misdiagnosis. As the osteoid osteoma may be difficult to identify and the MR features easily misinterpreted, optimisation of MR technique is crucial in reducing the risk of missing the diagnosis. Unexplained areas of bone marrow oedema in particular require further imaging (scintigraphy and CT) to exclude an osteoid osteoma.