Image-guided synovial biopsy with a focus on infection.

Image-guided biopsy of the synovium is a relatively uncommon but safe procedure with a high-diagnostic yield in the correct clinical scenario. Whilst surgical and arthroscopic techniques are still commonly performed and remain the gold standard, they are more invasive, expensive and not widely available. Ultrasound and X-ray-guided synovial biopsy are being increasingly performed by radiologists to diagnose both native and periprosthetic joint infection (PJI) to guide surgical and microbiological management. The purpose of this review article is to present the historical background to synovial biopsy particularly related to potential joint infection, including common and uncommon pathogens encountered, sampling techniques and pitfalls, focusing mainly on its role in PJI and its role in patient pathways and decision-making within a joint infection multi-disciplinary framework.

Does T2 inversion aid in identifying disc pathologies?

OBJECTIVE: T2 inversion sequence is used in routine radiology practice mainly to heighten contrast resolution within the region to be studied but no evidence exists in current literature to assess it's true efficacy for lumbar disc degeneration. The objective of this study was to analyse T2 inversion and evaluate it's efficacy in assessment of lumbar disc pathology,. MATERIALS AND METHODS: This retrospective single-centre study included 50 randomly selected patients presenting with back pain and radiculopathy. T2 inversion sequence was obtained in both axial and sagittal planes in addition to routine sequences. All the Magnetic Resonance Imaging (MRI) procedures were performed on 3T. One senior Musculoskeletal (MSK) radiologist, 2 general radiologists and a spinal surgeon blinded to final results reviewed images for the various disc pathologies individually analysing conventional and T2 inversion images. Data was analysed using Fischer's test and Chi2 test with a p value of <0.05 considered as significant. RESULTS: Fifty randomly selected patients (mean age was 47.3 years(range 35-55 years) with back pain and radicular symptoms were included. The spectrum of disc pathologies included protrusions, annular fissures, discal cysts and calcified discs. Based on the above findings, T2 inversion sequence is not proved to be an alternative imaging sequence to routine MR imaging sequences for the depiction of various disc pathologies. CONCLUSION: T2 inversion sequence does not increase the depiction of various lumbar disc pathologies in comparison with conventional sequences when used by experienced MSK radiologists. It may highlight abnormalities better for relatively inexperienced readers such as general radiologists and spinal surgeons.

Current progress and future trends in imaging of musculoskeletal bone tumours.

Plain radiographs and MRI remains the gold standard imaging modality for bone tumour and tumour like lesions. Several imaging techniques have been developed to be used in conjunction, but doubt remains over how much additional diagnostic information they provide over and above routine MRI bone tumour sequences. Given the plethora of new modalities, this review aims to highlight some of them and how they may help in the diagnostic assessment of musculoskeletal bone tumours.

Comparison between conventional CT and grayscale inversion CT images in the assessment of the post-operative spinal orthopaedic implants.

AIM: To compare the accuracy of the inverted greyscale CT versus the conventional CT in the assessment of post-operative spinal orthopaedic implants and osseous fusion. METHODS: 50 patients who had CT as part of their routine spinal implant follow up were evaluated for the presence of fusion, fracture and loosening with conventional CT and with greyscale inverted CT images. 3 independent observers assessed the images 2 months apart. Diagnostic performance (sensitivity and specificity) of the conventional and greyscale inversion images relative to the reference standard were calculated. Agreement with the reference standard was assessed using Cohen's kappa for conventional and greyscale inversion images. RESULTS: Correct classifications increased when using the greyscale inverted CT images for each reader compared to conventional CT images (40-46, 39 to 42 and 41 to 44 (out of 50)). Inverted images demonstrated better agreement with the reference standard than conventional grayscale images for assessment of fusion (kappa of 0.588 for inverted CT versus 0.484 for conventional CT) and loosening (kappa 0.386 for inverted versus 0.293 for conventional). Sensitivity was increased for assessment of fusion and loosening. McNemar's test performed for assessment of sensitivity differences showed statistical significance (p = 0.038 for fusion and p = 0.0313 for loosening). CONCLUSION: Greyscale inversion CT is a useful adjunct which has advantages (improved sensitivity and better agreement) over conventional CT imaging in cases of fusion and loosening of metallic implants following spinal instrumentation. We recommend the use of both the greyscale inversion CT images and conventional CT imaging when assessing post-operative spinal orthopaedic implants.

Birmingham Intervention Tent Technique (BITT): A Technical Note.

Objective We describe a novel and safe CT biopsy technique that we have termed the "Birmingham intervention tent technique (BITT)." This technique is ideal for biopsying osseous lesions where a direct approach is not possible due to difficult positioning. Methods The BITT uses a plastic surgical forceps clamp attached at an angle to the biopsy needle, creating a tent shape. The finger rings of the forceps is stabilized on the table. Results In our institution, we have already used the BITT successfully in over 10 cases. Conclusion The BITT is an inexpensive and reproducible technique.

The value of chest and skeletal staging in parosteal osteosarcoma: two-centre experience and literature review.

OBJECTIVE: To determine the value of chest and skeletal staging in patients with parosteal osteosarcoma (POS), and the incidence of late local and chest recurrence. MATERIALS AND METHODS: Retrospective review of patients across two institutions with histological confirmation of POS diagnosed between January 2007 and March 2020. Data collected included age, sex, skeletal location, results of chest CT and whole-body bone scintigraphy (WB-BSc) or whole-body MRI (WB-MRI) obtained at initial diagnosis. The histological tumour grade based on surgical resection specimens was classified as low-grade POS (LG-POS) and dedifferentiated POS (DD-POS). Findings of chest CT and skeletal staging were correlated with tumour grade. Follow-up chest CT and MRI studies were reviewed to determine the rate of late lung metastases and local recurrence. RESULTS: There were 27 males and 44 females, mean age 33 years (range 12-79 years). The femur (n = 43) and tibia (n = 14) were the most commonly involved bones. From surgical resection histology, 42 (59.2%) were LG-POS and 29 (40.8%) were DD-POS. WB-BSc/WB-MRI showed no skeletal metastases, while 1 case of DD-POS presented with bilateral calcified lung metastases. At follow-up, 7 patients (9.9%) developed lung metastases (mean of 18.9 months, range 10-48 months) from initial presentation, of which all were DD-POS. All but 1 patient who developed subsequent lung metastases had a local recurrence. CONCLUSIONS: Skeletal staging is unlikely to be of value in POS. Staging chest CT is very unlikely to demonstrate lung metastases in LG-POS and could be limited to DD-POS, particularly at the time of local recurrence.

Tibial tuberosity lesions.

Lesions of the tibial tuberosity are very rare but often present a diagnostic dilemma due to their unusual location and appearances. Although some pathologies affecting this region are commonly seen elsewhere in the skeleton, they may have atypical imaging appearances and morphological characteristics when present at the tibial tuberosity. The present review describes the developmental stages of the tibial tuberosity, explaining why this area is prone to degenerative tractional changes and injury, and also highlights various pathologies including benign and malignant osseous lesions and trauma/degenerative related abnormalities.

Diagnostic concordance between ultrasound-guided core needle biopsy and surgical resection specimens for histological grading of extremity and trunk soft tissue sarcoma.

OBJECTIVE: Determination of accurate histological grade impacts on management for soft tissue sarcomas (STSs). Although ultrasound-guided core needle biopsy (US-CNB) accurately establishes tumour subtype compared with surgical specimens, the concordance for tumour grade is uncertain. The aim of this study was to assess the concordance between US-CNB and surgical resection specimens for tumour grade in trunk and extremity STS. MATERIALS AND METHODS: Retrospective review of consecutive patients presenting with extremity/trunk STS. Data collected included patient age, gender, lesion location, US-CNB diagnosis and grade, and surgical histology and grade. The histological diagnosis and tumour grade from US-CNB was compared with surgical resection histology. RESULTS: A total of 118 patients were included, 76 males and 42 females with a mean age of 54 years (range 10 months-90 years old). STS size ranged from 26 to 350 mm (mean 89.5 mm). All US-CNB procedures were performed with a 14G biopsy needle with a mean number of 5 passes. First US-CNB was diagnostic for STS in all patients, and provided adequate tissue for tumour grading in all but one patient. Histological tumour subtype on US-CNB matched surgical specimens in all cases, with 25 (21.2%) STS being low grade and 93 (78.8%) high grade. The concordance for tumour grade was 96.6%, with no difference between low- and high-grade STSs (p > 0.05). The 4 cases of mismatch were considered low grade on US-CNB, but subsequently high grade on surgical resection. CONCLUSION: US-CNB of STS can reliably predict histological tumour grade compared with surgical resection specimens, thus allowing confident treatment decisions to be made.

Ultrasound of glenoid labrum with MR arthrographic correlation.

Ultrasound (US) is a reliable non-invasive method to image the rotator cuff tendons. Even though glenoid labral pathology is common, it is not routinely looked at as part of the shoulder ultrasound protocol. Currently, the gold standard for labral imaging remains MR arthrography. However, given the rather long waiting list and cost implications, US may be used as a modality to quickly screen the shoulder for gross labral pathology. Whilst there is relative paucity of the literature outlining labral pathology on US, there is none correlating sonographic and corresponding MRI appearances. We present a pictorial review highlighting scanning positioning, US and corresponding MRI appearances of a normal labrum and various labral pathologies. We discuss useful scanning tips and characteristic US signs which can help the radiologist.

Osteochondromas of the cervical spine-case series and review.

OBJECTIVE: Cervical spine osteochondromas are rare with approximately 3% of solitary and 7-9% of hereditary osteochondromas occurring in the spine. Almost 50% of spinal osteochondromas occur in the cervical region. METHODS: A search of osteochondroma of cervical spine was performed of our radiology database. RESULTS: In this study, we present 11 cases of adult cervical spine osteochondromas. These predominantly involved the posterior elements. The cartilage cap was more than 2 cm in 2 cases. There was cord compression in 1 case, foraminal narrowing in 2 patients and vertebral artery compression in 1 case. 6 patients underwent excision with majority being osteochondroma. There was only one case of chondrosarcoma. CONCLUSION: Osteochondromas of cervical spine and extremely rare and symptomatology are due to mass effect. One should be aware of this entitly when analysing cervical spine for neck pain or lump.

Standard operating procedure of image-guided intervention during the COVID-19 pandemic: a combined tertiary musculoskeletal oncology centre experience.

AIM: To evaluate the response measures in continuing an image-guided intervention service in two tertiary-level musculoskeletal oncology centres during the COVID-19 pandemic. MATERIALS AND METHODS: This study was a retrospective review of all patients undergoing image-guided intervention in the computed tomography (CT) and normal ultrasound (US) rooms from 24 March 2020 to 24 May 2020 (during the COVID-19 pandemic peak) at Royal National Orthopaedic Hospital, London, and Royal Orthopaedic Hospital, Birmingham, UK. Measures were put in place to address air pressures, airflow direction, aerosol generation, and the safe utilisation of existing scanning rooms and work lists for interventional procedures. RESULTS: Three hundred and thirty-one patients (164 at Royal National Orthopaedic Hospital and 167 at Royal Orthopaedic Hospital) underwent image-guided procedures at both sites in the CT and US rooms. At the Royal National Orthopaedic Hospital, 40% of all procedures were performed under general anaesthesia. These consisted of 47 CT biopsies, 7 CT radiofrequency ablations (RFAs), and 12 US biopsies. At the Royal Orthopaedic Hospital, 86% of all procedures were performed under local anaesthetic, with no general anaesthetic procedures. These consisted of 61 CT biopsies and 83 US biopsies. All 256 patients having procedures in the CT room had no post-procedural complications or COVID-19-related symptoms and morbidity on follow-up. CONCLUSION: By adopting a pragmatic approach with meticulous planning, a limited, but fully functional image-guided interventional list can be run without any adverse patient outcomes.

Langerhans cell histiocytosis of the shoulder girdle, pelvis and extremities: a review of radiographic and MRI features in 85 cases.

OBJECTIVES: To describe the radiographic and MRI features of histologically proven Langerhans cell histiocytosis (LCH) of the bone. MATERIALS AND METHODS: A retrospective review of the radiographic and MRI features of 85 histologically proven cases of skeletal LCH over a 12-year period. Clinical data recorded included age, gender and location. Radiographic features evaluated included Lodwick grading, cortical/periosteal response and matrix mineralisation. MRI features assessed included lesion size and T1-weighted signal intensity (T1W SI), nature of margin, hypointense rim, enhancement pattern, bone marrow and soft tissue oedema, soft tissue mass, fluid-fluid levels, the penumbra sign and the budding and bulging signs. RESULTS: The study included 85 patients, 54 males and 31 females with mean age of 13 years (range 1-76 years). The femur was the commonest bone involved (38.8%), followed by the scapula (9.4%), clavicle (8.2%), ilium (8.2%) and ischium (8.2%). The mean maximal lesion size was 40 mm (range 16-85 mm). The commonest radiographic appearance was of a lytic lesion with no appreciable sclerotic rim, an intact expanded cortex and either absent or laminated periosteal response. MRI demonstrated a hypointense rim (41.5%), the budding (31.7%) and bulging (36.6%) signs, eccentric extra-osseous mass (42.7%), prominent bone marrow (95.3%) and soft tissue oedema (84.1%). Rarer features included haemorrhage (2.4%), the penumbra sign (3.5%) and fluid-fluid levels (2.4%). Thirteen of 25 post-contrast studies showed peripheral/rim enhancement with central necrosis. CONCLUSIONS: LCH classically presents as a moderately aggressive lytic bone lesion on radiography, with prominent reactive bone and soft tissue oedema being a characteristic feature on MRI.

Is acetabular morphology related to trochlear dysplasia?

PURPOSE: To evaluate the correlation between trochlear dysplasia and acetabular coverage. MATERIALS AND METHODS: 109 retrospective CT studies referred from the young adult knee clinic were independently reviewed by two observers. Anterior acetabular (AASA) and posterior acetabular (PASA) sector angles were calculated bilaterally on axial CT. Trochlear dysplasia was graded using the Dejour classification (A-D). ANOVA test was used. RESULTS: Dejour types A, B and D trochlear dysplasia were associated with a significantly increased AASA (P value = 0.0011). CONCLUSION: Our results demonstrate a significant relationship between trochlear dysplasia and anterior acetabular coverage, as measured by AASA.

Surface adhesive and hand-aided needle-assisted biopsy technique (SAHNA).

OBJECTIVE: We describe a novel and efficient CT biopsy technique that we have termed 'skin adhesive and hand-aided biopsy technique', shortened to the acronym SAHNA. This technique is ideal for biopsying surface osseous lesions where there is a lack of subcutaneous fat. This avoids the need for the radiologist's hand to be in close proximity to the CT scanner beam at the time of intervention. METHODS: The SAHNA technique uses a plastic surgical forceps towel clamp to stabilise the biopsy needle just proximal to the lesion after piercing through the skin. The clamp itself is stabilised via a self-adhesive dressing which is stuck down to the skin at its shank. RESULTS: In our institution, we have already used the SAHNA technique successfully in over 5 cases. CONCLUSION: The SAHNA technique is a widely accessible and effective way of stabilising the CT biopsy needle in technically challenging superficial bony lesions.