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.

An unusual case of nodular fasciitis presenting as an intra-tendinous mass.

Nodular fasciitis is a benign soft tissue pseudotumour typically occurring in the upper extremities, head and neck, thigh and trunk. It is most commonly seen in subcutaneous locations but also can be present in intramuscular and intermuscular (fascial) locations. Its occurrence in the hand is rare, and while it can occur in close proximity to tendons, its presentation as an intra-tendinous mass has not been previously described. We present a unique and rare case of nodular fasciitis arising within the flexor digitorum profundus (FDP) tendon of the hand in a 16-year-old female. The patient presented with a painful swelling in the volar aspect of the base of her left middle finger, with progressive flexion deformity of the finger. Ultrasound and magnetic resonance imaging revealed a mass within the FDP tendon of the middle finger. An ultrasound-guided biopsy revealed a diagnosis of nodular fasciitis. Given the self-limiting nature of the condition, she was managed conservatively with close clinical and imaging follow-up. This case highlights the importance of considering nodular fasciitis in the differential diagnosis of an intra-tendinous lesion in the hand, even though it is a rare occurrence in this location. The clinical presentation, diagnostic workup, and management of this unique case are discussed, emphasising the potential for its misdiagnosis as a malignancy which can have important implications in management.

Can Non-Contrast 3T MRI scans predict the type of labral procedure in hip arthroscopy?

PURPOSE: The study proposed a simple classification system that aimed at predicting the labral procedure during hip arthroscopy using images from unenhanced 3T MRI scans. PATENTS AND METHODS: Forty patients undergoing hip arthroscopy had their MRI scans reviewed pre-operatively by one of two senior radiologists and classified into: type 1: stable labrum with intra-substance degeneration (no labral repair required), type 2: unstable labrum, no intra-substance degeneration (labral repair required), or type 3: unstable labrum with intra-substance degeneration (Labral repair not feasible). Hip arthroscopy is carried out by one of two surgeons and classified accordingly while blinded to the radiologists' assessment. RESULTS: The pre-operative radiological classification managed to predict the labral procedure in 29 cases out of 40 (72.5%). The gamma value was 0.83, and the kappa value was 0.46 denoting moderate agreement. The inter-class correlation coefficient was 0.52 indicating moderate reliability. CONCLUSION: The proposed classification showed a moderate agreement between the radiological findings and arthroscopic findings. As we cannot accurately correlate the MRI findings with the type of surgical management, the surgeon should be prepared for all scenarios of labral procedures. LEVEL OF EVIDENCE: Level IV (case series).

Should the webspaces be a review area for Mortons neuroma on computed tomographies performed for metatarsalgia?

PURPOSE: Morton's neuroma-bursal complex (MNBC) is a common cause of metatarsalgia which is usually investigated with ultrasound. Patients presenting with metatarsalgia may also have computed tomography (CT) as part of their investigation to look for alternative causes such as stress fracture. Although CT is considered to be of most use in assessing the bones in this scenario, the soft tissues can also be reviewed. This study analyses whether MNBC can reliably be detected on CT in patients presenting with metatarsalgia. MATERIAL AND METHODS: 43 cases were identified on the Radiology Information System where both CT and ultrasound had been undertaken to assess for metatarsalgia. Two blinded consultant musculoskeletal radiologists retrospectively reviewed the CTs to determine the presence or absence of MNBC and this was compared to the ultrasound reports. RESULTS: There was a mean sensitivity of 45.5% and mean specificity of 62.5%. Mean accuracy was 52.3% and Youden's index was 0.080. There was fair agreement between the two reviewers with Cohen's κ of 0.62. CONCLUSIONS: Sensitivity and specificity of CT for MNBC are poor. CT should not be used as an isolated modality to make a definite diagnosis regarding the presence or absence of a MNBC.

Multimodality imaging of greater trochanter lesions.

PURPOSE: Greater trochanter (GT) lesions are relatively uncommon. They can be traumatic, infective including tuber-culosis, inflammatory, and neoplastic (primary and metastatic osseous lesions). Although imaging of greater trochanter lesions remains essential for differential diagnoses, an image-guided biopsy is a mainstay for diagnosis and to guide subsequent management. MATERIAL AND METHODS: A retrospective search for the word 'greater trochanter' was performed of a computerised radiology information system (CRIS) of a tertiary referral centre for orthopaedic oncology over a period of 12 years (2007-2019). This revealed 6019 reports with 101 neoplasms. The imaging, histology, and demography were reviewed by a dedicated musculoskeletal radiologist. RESULTS: We identified 101 GT neoplasms with a mean age of 51.5 years (range 6 to 85 years) and a slight female predominance of 1.2 : 1 (46 males and 55 females). Using 30 years of age as a cut-off, we further segregated the patient cohort into 2 groups: 26 (25.74%) lesions in patients less than 30 years age and the remaining 75 (74.26%) lesions in patients over 30 years old. Chondroblastoma was the most common neoplasm in patients below 30 years of age, and metastases were the most common neoplasms in patients over 30 years of age. CONCLUSIONS: Greater trochanter pathologies show a broad spectrum of aetiologies. Imaging including radiographs, computed tomography, magnetic resonance imaging, and nuclear medicine scans help to narrow down the differen-tials diagnosis.

Calcified Thoracic Disc - A descriptive classification with clinical and management implications.

Introduction and Objective: Thoracic disc calcification is a radiological finding which may be incidental or diagnosed in patients presenting with myelopathy due to spinal cord compression. We performed a study to analyze the imaging patterns of calcified thoracic discs (CTDs). Patients and Methods: A retrospective review of the spinal and radiology database of a tertiary referral orthopedic hospital was conducted for the incidence of CTDs between 2007 and 2020. Patients' demographics and radiological findings were recorded. The relationship between disc size, morphology, spinal cord compression, and management was assessed. Results: Fifty-one cases of CTDs were identified. The mean size of CTD was 806.2 mm3 (range: 144-2340). The most common level of disc calcification was T9-T10 (24%) in 12 patients. Thoracic disc calcifications in our series commonly involved disc "protrusion" in 67% (34 patients), followed by "mushroom" type in 31% (16 patients) and "extrusion" in 2% (1 patient). 37% (19 patients) had spinal cord compression with 12% (6 patients) undergoing surgical interventions. There was no statistically significant difference in the mean sizes of CTD between the groups with and without spinal cord compression (P = 0.566, independent sample t-test). Patients with "mushroom" type calcification were more likely to have surgical intervention (P = 0.01, Fisher's exact test). Conclusion: Thoracic disc calcifications, while common, can still be underdiagnosed till late myelopathic deterioration. Care of the elderly physicians, spinal surgeons, and radiologists need to be aware of them to guide diagnosis and management. Our study demonstrates that disc morphology plays a vital role in myelopathic presentation and therefore determines the need for surgical intervention instead of the absolute size of disc calcification.

A New Radiological Scoring System as a Method of Assessing Sclerotherapy Treatment Response for Aneurysmal Bone Cysts: A Retrospective Study.

Background A widely accepted set of imaging criteria or classification has not yet been adopted to evaluate response to treatment by percutaneous sclerotherapy for aneurysmal bone cyst (ABC). In this article, we described and illustrated the Royal Orthopaedic Hospital (ROH) scoring system which is a new, reproducible, and objective tool to evaluate the radiological response. We also reported our institutional experience in the efficacy of computed tomography (CT)-guided sclerotherapy for treating such lesions. Patients and Methods A retrospective analysis was conducted for 19 patients who underwent CT-guided sclerotherapy with doxycycline and albumin to treat ABC. Follow-up magnetic resonance imaging, at a minimum of 12 months, was assessed according to the four ROH scoring system parameters: cystic component, fluid-fluid level, presence of consolidation, and cortical integrity. The cumulative score was used to grade response as either: excellent, good, equivocal, or poor. Results Out of 19 patients with a mean age of 17.8 years, 11 cases occurred in the long bones, 5 cases in the pelvis, and 1 in each of the C3 vertebral body, scapula, and talus. The mean parameter of response score for cystic component was 2, fluid-fluid level was 1.3, consolidation was 2, and cortical integrity was 2.1. Four cases showed excellent response, 12 cases showed good response, 2 cases showed equivocal response, and 1 case showed poor response. Interrater reliability was excellent (κ = 0.9). Conclusion The ROH scoring system provides the radiologist and surgeon with an objective method to score imaging parameters of response independently and achieve a grade based on the cumulative score.

The clinical significance of indeterminate pulmonary nodules in patients with primary bone sarcoma: a systematic review.

OBJECTIVE: To report the incidence of indeterminate pulmonary nodules (IPN) and the rate of progression of IPNs to metastasis in patients with primary bone cancers. We also aimed to evaluate clinical or radiological parameters that may identify IPNs more likely to progress to metastatic disease and their effect on overall or event-free survival in patients with primary bone sarcoma. METHODS: A systematic search of the electronic databases Medline, Embase, and Cochrane Library was undertaken for eligible articles on IPNs in patients with primary bone sarcomas, published in the English language from inception of the databases to 2023. The Newcastle-Ottawa Quality Assessment Form for Cohort Studies was utilized to evaluate risk of bias in included studies. RESULTS: Six studies, involving 1667 patients, were included in this systematic review. Pooled quantitative analysis found the rate of incidence of IPN to be 18.1% (302 out of 1667) and the rate of progression to metastasis to be 45.0% (136 out of 302). Nodule size (more than 5 mm diameter), number (more than or equal to 4), distribution (bilaterally distributed), incomplete calcification, and lobulated margins were associated with an increased likelihood of IPNs progressing to metastasis, however, their impact on overall or event-free survival remains unclear. CONCLUSION: The risk of IPNs progressing to metastasis in patients with primary bone sarcoma is non-negligible. Large IPNs have a high risk to be an actual metastasis. We suggest that IPNs in these patients be followed up for a minimum of 2 years with CT imaging at 3, 6, and 12 month intervals, particularly for nodules measuring >5 mm in average diameter. ADVANCES IN KNOWLEDGE: This is the first systematic review on IPNs in patients with primary bone sarcomas only and proposes viable management strategies for such patients.

Alteration in the Cross-sectional Area (CSA) Ratio of the Paraspinal Muscles following Vertebral Insufficiency Fractures.

Background Vertebral insufficiency fractures in the elderly are associated with increased morbidity and mortality. Early diagnosis is essential to direct patient-specific rehabilitation. Aims We hypothesize that in patients with vertebral insufficiency fractures, there is atrophy of the psoas and paraspinal muscles with alteration in the cross-sectional area (CSA) of the muscles. Materials and Methods Magnetic resonance imaging (MRI) studies for 100 consecutive patients, older than 60 years presenting with lower back pain, were included in the study. For each MRI study, the CSA of the psoas and paraspinal muscles (multifidus) at the level of L4/5-disc space was measured to calculate the cross-sectional area ratio (CSAR) by two readers. One reader repeated the measurements after an interval of 2 weeks. We divided the patients ( n = 100) into various groups based on the number of vertebral fractures. Results In total, 77 patients with vertebral body fractures (48 with one, 16 with two and 13 with more than two fractures) were identified with a mean age of 73 (range 60-92) years. The ratio of multifidus CSA to psoas CSA was calculated with mean values of each group (1-4) as 2.56, 1.89, 2.09 and 2.16, respectively. There was statistically significance difference of the CSAR between the cohorts ( p -value = 0.0115). Conclusion Vertebral insufficiency fractures in the elderly are associated not only with atrophy of psoas and the multifidus group of muscles as evident by the CSA values, but they also affect the CSAR depending on the number of fractures. This finding may help to direct targeted patient-specific physiotherapy rehabilitation and interventions to prevent further such fractures.

Does Chemical Shift Magnetic Resonance Imaging Improve Visualization of Pars Interarticularis Defect?

Introduction A unilateral or bilateral pars interarticularis defect (spondylolysis) is a leading cause of axial back pain in adolescent athletes. Currently, a spectrum of imaging modalities is used for assessment of pars interarticularis defects. Objectives The aim of this study is to compare the accuracy of chemical shift sequence (magnetic resonance imaging [MRI]) technique to conventional MRI sequences in the detection of pars defects. Patients and Methods Conventional T1, T2, and short tau inversion recovery sagittal and axial, as well as "in-" and "out-" phase chemical shift sagittal MRI sequences of 70 consecutive patients referred for low back pain were reviewed. Demographic details, clinical indication, and presence/diagnosis of pars defects using a 5-point Likert scale on both conventional and chemical shift MRI sequences. Spearman's correlation was used for statistical analysis. Intraclass correlation coefficient analysis was evaluated to assess the intraclass reliability between observers. Data were analyzed using DATAtab web-based statistics software (2022). Results A total of 70 patients with an average age of 54.34 years with a female predominance were included. There were 11 pars defects in the cohort. Both in and out phases of chemical shift imaging were able to identify pars defect and intact pars. However, out phase was relatively better in delineating pars defects, while the in phase was superior in identifying an intact pars, though this was not statistically significant. There was good intra- and interobserver reliabilities. Conclusion Chemical shift MRI sequence is a quicker, complementary technique to assess and analyze pars interarticularis confidently than conventionally utilized MRI sequences in patients being evaluated for axial back pain.

Measurement Analysis of Ice Ball Size during CT-Guided Cryoablation Procedures for Better Prediction of Final Ice Ball Size and Avoidance of Complications.

Introduction Cryoablation is the destruction of living tissue by the application of extreme freezing temperature. There has been an increase in the use of cryoablation in the management of musculoskeletal lesions, in particular fibromatosis. Aim This study aimed to measure the average and relative increase in size of the cryoablation ice ball after the first (10 minutes) and second freeze cycles (20 minutes) to accurately predict the size of the ice ball between first and second freezes to help prevent any unwanted damage of the nearby skin and neurovascular structures. This is especially important when ablating in relatively small body parts such as in the appendicular skeleton. Material and Methods Eight patients treated with cryoablation over a 12-month period for fibromatosis were, included in the study. The size and volume of the ice ball were measured during the first and second cycle of cryoablation. Results The average patient age of the cohort was 35.6 years old (min 28 and max 43). There was female predominance in the study (3:2, F:M). There was a significant increase (26%) in the linear dimensions and almost doubling in the volume of the ice ball between freeze cycles ( p -value = 0.0037 for dimensions and p -value = 0.0002 for volumes). Conclusion This pilot study is a preliminary attempt to predict the eventual size of the ice ball during cryoablation procedures when treating cases of fibromatosis. This should help in planning cryoablation to ensure decrease morbidity by preventing injury to adjacent critical structures (neurovascular bundle and skin).

The T1 Ratio of Marrow (TROM) as a Novel Tool to Identify Metastatic from Nonmalignant Marrow Lesions of the Spine: A Pilot Study.

Objective The purpose of this study was to analyze quantitative values of normal and abnormal marrow on T1-weighted images of spine, to propose a ratio for T1 values of abnormal to normal vertebrae, and to assess whether this ratio could be helpful in predicting presence of neoplastic lesions in the spine. Materials and Methods One-hundred randomly selected magnetic resonance imagings of lumbar spine without infection, fracture, and tumor were selected to form normal cohort. A second cohort of 100 metastasis of lumbar spine was identified. Ratio of T1 value of vertebral body to the T1 value of the inferior vertebral body was performed for normal cohort from D11 to L5. Ratio of T1 value of metastasis to adjacent normal vertebral body was done for metastatic cohort. Data was analyzed using standard t -test and kappa was performed for intra- and inter-observer reliability. Results A decline in T1 value of abnormal to normal marrow was seen in patients with metastasis that was statistically significant. We call this the T1 ratio of marrow (TROM). The sensitivity and accuracy with the cutoff value of TROM at 0.7 (92% sensitivity, 97.1% accuracy) are better than at 0.6 (75% sensitivity, 96.2% accuracy) or 0.5 (47% sensitivity, 93.2% accuracy). A subset analysis of the other T1 hypointense benign lesions including atypical hemangiomas and focal marrow hyperplasia, however, revealed overlapping TROM values with the metastatic cohort. Conclusion Using the TROM on T1-weighted images could not confidently differentiate malignant from benign T1 hypointense lesions of the spine.

Isolated pathologies of Tensor Fasciae Latae: Retrospective cohort analysis from a tertiary referral centre.

Introduction: Tensor Fasciae Latae (TFL) and the iliotibial band (ITB) act as a single functional unit in maintaining pelvic stability whilst standing, walking, or running in human beings. The Tensor Fasciae Latae (TFL) muscle acts across the hip and the knee joint. Consequently, though its pathologies traditionally present with lateral hip pain, identifying the precise clinical diagnosis can be a challenge. Patients and methods: A retrospective search for the keyword 'Tensor Fasciae Latae'/iliotibial band (ITB) was performed of our Radiology Information System (RIS) and Picture Archiving and Communication System (PACS), Computerised Radiology Information System (CRIS) at our tertiary orthopaedic referral centre of a for orthopaedic oncology over a period of 13 years (2007-2020). Data was collected from RIS, oncology database and local histopathology laboratory records. Patient demographics, clinical characteristics, complementary imaging and clinical management outcome were documented. Results: We identified 35 patients with a mean age of 66 years (range 19-94 years). There were 18 female and 17 male patients. Lateral hip lump and pain were the most frequent clinical finding/presentation features. A variety of pathologies such as benign and malignant tumours, including vascular and tumour mimic lesions involving the TFL muscle were identified. Atrophy and pseudohypertrophy of TFL was the commonest pathology found; accounting for two thirds of the cases. Conclusion: Tensor Fasciae Latae (TFL) can be afflicted with a broad spectrum of pathologies. Radiological imaging especially cross-sectional imaging modality is crucial in guiding appropriate patient management of TFL conditions. Our analysis suggests isolated TFL lesion are more likely to be benign conditions, presenting commonly as hip pain and swelling.

Metachronous Osteoid Osteoma of the Mid-Diaphysis of the Fibula and Distal Humerus: A Case Report.

Osteoid osteomas are mostly solitary. We report a case of metachronous osteoid osteoma of mid-diaphysis of fibula followed by distal humeral osteoid osteoma after a 7-year interval.

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.

Imaging review of normal anatomy and pathological conditions involving the popliteus.

Popliteus is an integral component of the posterolateral corner of the knee. We review the anatomy and various pathologies affecting the popliteus.

Spontaneous Isolated Iliopsoas Tendon Tear in Elderly-Case Report and Review of Literature.

Iliopsoas tendon tears are rare. These typically occur in young and can be associated with avulsion fractures of lesser trochanter. We report a case of full thickness rupture of iliopsoas tendon in 87-year-old male without avulsion of the lesser trochanter.

A Rare Presentation of Osteoid Osteoma in a 77-Year-Old Patient, Treated with Computer Tomography-Guided Percutaneous Radiofrequency Ablation.

Osteoid osteoma (OO) is a benign bone forming tumor characterized by small size and a disproportionate amount of pain. They are most commonly seen between the ages of 5 and 30 years; however, they can be seen in the older patient albeit infrequently. The hands and feet are the least common site of OO among the extremity bones. We present a case of an OO in the hand of a 77-year-old man who underwent successful treatment with computed tomography-guided percutaneous radiofrequency ablation. We believe this is the oldest recorded patient in the medical literature with a histologically confirmed OO. The condition should therefore be considered in the differential diagnosis of a painful sclerotic bone lesion in this age group to avoid a delay in diagnosis and subsequent treatment.