A single cell atlas of frozen shoulder capsule identifies features associated with inflammatory fibrosis resolution.

Frozen shoulder is a spontaneously self-resolving chronic inflammatory fibrotic human disease, which distinguishes the condition from most fibrotic diseases that are progressive and irreversible. Using single-cell analysis, we identify pro-inflammatory MERTKlowCD48+ macrophages and MERTK + LYVE1 + MRC1+ macrophages enriched for negative regulators of inflammation which co-exist in frozen shoulder capsule tissues. Micro-cultures of patient-derived cells identify integrin-mediated cell-matrix interactions between MERTK+ macrophages and pro-resolving DKK3+ and POSTN+ fibroblasts, suggesting that matrix remodelling plays a role in frozen shoulder resolution. Cross-tissue analysis reveals a shared gene expression cassette between shoulder capsule MERTK+ macrophages and a respective population enriched in synovial tissues of rheumatoid arthritis patients in disease remission, supporting the concept that MERTK+ macrophages mediate resolution of inflammation and fibrosis. Single-cell transcriptomic profiling and spatial analysis of human foetal shoulder tissues identify MERTK + LYVE1 + MRC1+ macrophages and DKK3+ and POSTN+ fibroblast populations analogous to those in frozen shoulder, suggesting that the template to resolve fibrosis is established during shoulder development. Crosstalk between MerTK+ macrophages and pro-resolving DKK3+ and POSTN+ fibroblasts could facilitate resolution of frozen shoulder, providing a basis for potential therapeutic resolution of persistent fibrotic diseases.

AL amyloidosis presenting with isolated lumbosacral radiculoplexus neuropathy.

A 45-year-old man presented with an isolated sciatic mononeuropathy, which then evolved into a lumbosacral radiculoplexus neuropathy. His initial symptoms included lower limb pain, sensory disturbance and later weakness, without autonomic dysfunction. Neurophysiology suggested a postganglionic neuropathy. MR and ultrasound scans of the thighs showed right sciatic nerve thickening, and CSF analysis showed albuminocytological dissociation. Fluorodeoxyglucose positron emission tomography (FDG PET) was unremarkable. He then developed orthostatic symptoms and urinary disturbance, and was found to have an IgM paraprotein. Fat aspirate, cardiac and whole-body imaging found no amyloid deposition, and genetic testing for transthyretin amyloidosis was negative. A bone marrow biopsy was unremarkable. However, neuropathology review of a proximal, fascicular nerve biopsy identified a lambda chain-restricted plasma cell population with positive Congo red staining, leading to a diagnosis of peripheral nerve restricted amyloid light amyloidosis. We discuss the diagnostic approach to this case from the perspectives of neurology, neurophysiology, radiology and neuropathology.

Dual-energy CT in the diagnosis of occult acute scaphoid injury: a direct comparison with MRI.

OBJECTIVES: Scaphoid injuries occult on plain radiography often require further imaging for definitive diagnosis. We investigate the utility of dual-energy computed tomography (DECT) for the detection of acute bone marrow oedema and fracture of scaphoid compared to MRI. MATERIALS AND METHODS: Twenty patients who presented acutely (without prior injury) to the emergency department with clinically suspected occult scaphoid fracture and had MRI of the wrist were prospectively recruited to have DECT (GE Revolution CT). Material decomposition images of the water-calcium base pair were generated and assessed in conjunction with the monochromatic images to permit correlation of marrow signal changes with any cortical disruption for fracture confirmation. The assessment was performed by two musculoskeletal radiologists blinded from MRI results. The statistical difference of MRI and reviewers' detection of acute bone oedema (1 = present, 0 = absent) was performed using the Friedman test (SPSS v.16). RESULTS: MRI showed acute scaphoid fracture and/or bone marrow oedema in 14/20 patients of which 6 also had cortical disruption. On DECT, reviewer A identified oedema in 13 and cortical disruption in 10 patients while reviewer B identified oedema in 10 and cortical disruption in seven of the 14 MRI positive patients. No statistically significant difference in oedema detection on MRI and reviewers of DECT (p value 0.61) but DECT was more sensitive at detecting cortical disruption. CONCLUSION: DECT has the capability to detect acute scaphoid oedema in addition to cortical fractures. However, compared to MRI, DECT has lower contrast resolution and less sensitive in the detection of mild oedema. KEY POINTS: • Dual-energy CT is able to detect acute traumatic scaphoid marrow oedema. • Dual-energy CT has greater detection rate of scaphoid fractures than MRI. • Dual-energy CT is an alternative to MRI for occult scaphoid injury.

Corrigendum to "Ectopic breast tissue presenting as an enlarging abdominal mass" [Radiology Case Reports 15 (2020) 733-740].

[This corrects the article DOI: 10.1016/j.radcr.2020.02.028.].

The anterolateral ligament in acute knee trauma: patterns of injury on MR imaging.

OBJECTIVE: To delineate the spectrum of traumatic knee injuries associated with injury of the anterolateral ligament of the knee (ALL). MATERIALS AND METHODS: A retrospective review of 200 MRI scans undertaken for acute knee trauma was performed. In each scan, the ALL was scored as normal, sprained or torn. The menisci, ligaments and tendons of each knee were also assessed. RESULTS: The mean age was 27.4 years (range, 9-69 years), and 71.5% (n = 143) of the patients were male. The anterolateral ligament (ALL) was graded as ruptured in 17 cases (8.5%), sprained in 58 cases (29%), normal in 116 cases (58%) and not visible in 9 cases (4.5%). Of cases with injury of the ALL (n = 75), there was associated injury of the anterior cruciate ligament (ACL) in 61 cases, medial collateral ligament (MCL) in 51 cases, popliteofibular ligament (PFL) in 29 cases, medial meniscus in 29 cases, lateral meniscus in 24 cases, lateral collateral ligament in 9 cases, posterior cruciate ligament in 8 cases, biceps femoris in 5 cases, popliteus tendon in 4 cases and fluid or oedema was seen adjacent to the iliotibial band in 59 cases. No cases of isolated ALL injury were seen. CONCLUSIONS: ALL injury is not uncommon in acute knee trauma and is typically associated with significant internal derangement of the knee, especially anterior cruciate ligament rupture, ITB sprain, medial collateral ligament injury, meniscal tears and injury to the popliteofibular ligament.

Ectopic breast tissue presenting as an enlarging abdominal mass.

Ectopic breast tissue (EBT) is an uncommon entity that occurs in about 6% of the population, more frequently in Asian people. It manifests as a nonspecific soft tissue mass that can develop in any location along the "milk-line," with the axilla being the most frequently reported location. As with normal breast tissue, both benign and malignant processes can arise from EBT. Therefore, imaging plays an important role in the adequate assessment of these soft tissue lesions, characterizing its shape, borders, internal components, and vascularity, as well as its relationship with the deep fascia and adjacent structures. Here we present a case of a 33-year-old female Indian patient with an 8 cm soft tissue mass in the upper left abdominal quadrant with a recent increase in size. Clinical and imagiological evaluation were nonspecific but established the nonaggressive behavior of the lesion. To ultimately exclude malignancy, an ultrasound-guided biopsy was performed providing the histological diagnosis of EBT. This case report illustrates the value of clinical, radiological, and histological correlation in the approach of indeterminate soft-tissue tumors, with special focus on lesions in close proximity to the native breasts, where EBT should not be forgotten amongst differentials.

Imaging and management of greater trochanteric pain syndrome.

Greater trochanteric pain syndrome (GTPS) is a commonly diagnosed regional pain syndrome with a wide spectrum of aetiologies, reflecting the anatomy of the structures outside the hip joint capsule. There are five muscle tendons that insert on to the greater trochanter and three bursae in the region of the greater trochanter. The term GTPS includes tendinopathies, tendinous tears, bursal inflammation and effusion. There are a range of treatments and therapies depending on the specific diagnosis and severity of the condition. Many patients with GTPS can be successfully managed conservatively with weight loss and non-steroidal anti-inflammatory drugs. Patients suffering from more chronic pain can receive varying degrees of symptomatic relief with lateral hip corticosteroid and local anaesthetic injections. More severe refractory cases of GTPS can be treated with surgical intervention. It is therefore important to make the correct diagnosis to ensure that appropriate management can be implemented. The clinical features of GTPS however are often non-specific because common conditions such as lumbar radicular pain and hip joint osteoarthritis can present with an almost identical form of lateral hip pain. The various diagnostic imaging modalities have particular strengths and weaknesses with ultrasound being the best first-line investigation due to its availability, low cost, dynamic nature and ability to guide treatments such as steroid injections. MRI can be very helpful in the further investigation of patients in whom there is diagnostic uncertainty as to the cause of lateral hip pain and in whom specialist orthopaedic referral is being considered.