A clinico-radiological review of chronic non-bacterial osteomyelitis in paediatrics, adolescents, and adults: demystifying a forgotten differential.

Chronic non-bacterial osteomyelitis (CNO), also known as non-bacterial osteitis, is a chronic autoinflammatory disease of unknown aetiology that primarily occurs in the paediatric population, although rare cases of adult-onset disease also exist. CNO has non-specific clinical and radiological presentations, and the affected population often present with bone pain of insidious onset secondary to sterile bony inflammation that can be associated with swelling, focal tenderness, and warmth at the affected sites. The pattern of bony involvement appears to be dependent on the age of onset, with adults frequently having axial skeletal lesions and children and adolescents often being affected in the appendicular skeletal sites. CNO is a diagnosis of exclusion, and imaging is heavily relied on to identify and characterise the bony lesions in addition to exclude diseases that can mimic CNO. Magnetic resonance imaging is often the reference standard with biochemical and histopathological findings being complementary. Although combining imaging methods can be used to facilitate the diagnosis, a single technique could be adequate depending on the clinical picture. Given the relatively rare incidence of CNO, limited awareness of the disease among care providers, and its similarity in clinical and radiological presentation to various bony diseases, there are often long delays in diagnosis, with adults being unfavourably affected compared to paediatrics and adolescents. This review of CNO will describe the condition, overview its clinical presentation, highlight the radiological features, and emphasise clinical pearls that can aid in diagnosis and ruling out the mimics.

Periarticular calcifications.

Periarticular calcification and ossification is a frequent finding on imaging and may sometimes pose a diagnostic challenge. The differential diagnoses for this radiological finding are wide and can be classified into broad groups such as idiopathic, developmental, trauma, burns, infection, tumor, connective tissue disease, crystalline, metabolic, vascular, and foreign bodies. With careful consideration of the clinical and imaging findings as well as awareness of mimickers of periarticular mineralization, the list of differential diagnoses can be narrowed down. This article aims to review the clinical-radiologic findings of periarticular calcified or ossified lesions with relevant imaging illustrations.

Evolving Practice Patterns Over Two Decades (1993-2013) in the Management of Desmoid-type Fibromatosis in British Columbia.

AIMS: Due to the rarity and varied natural history of desmoid-type fibromatosis, evidence-based treatment standards for this disease remain lacking. This study evaluated outcomes in patients with desmoid-type fibromatosis managed at a Canadian institution over two decades. MATERIALS AND METHODS: Records of 227 patients with desmoid-type fibromatosis referred from 1990 to 2013 were retrospectively reviewed to investigate management strategies including active surveillance, surgery, radiation therapy, cryoablation, and systemic therapy, including tamoxifen and chemotherapy. RESULTS: Thirty-two per cent of cases were men, median age 40 years, median tumour size 5.4 cm. Initial treatments were surgery (79%), tamoxifen (13%), radiation therapy (5.0%), chemotherapy (1.8%) and cryoablation (1.2%). Active surveillance was used upfront in 26% of cases, most after 2005. At a median follow-up of 77 months, one patient died of disease, 13 died of unrelated causes and the remainder were alive with no evidence of disease (56%), stable/responding disease (33%) or progressive disease (4%). The recurrence rate was 25% after upfront surgery. Response rates and disease control rates were 40% and 76% for active surveillance; 68% and 96% for radiation therapy; 31% and 67% for tamoxifen; and 53% and 80% for chemotherapy. On univariable analysis, factors associated with a higher recurrence after initial surgery were young age (P = 0.012), male gender (P = 0.012) and extremity location (P = 0.005). On multivariable analysis, only young age was significantly associated with recurrence risk (P = 0.010). CONCLUSIONS: Active surveillance was associated with spontaneous regression and long-term disease control consistent with other studies. Primary radiation therapy appeared to provide a similar response and disease control compared with systemic treatments and may be a viable option for patients who are not candidates for surgery or active surveillance.

Detection of occult, undisplaced hip fractures with a dual-energy CT algorithm targeted to detection of bone marrow edema.

The purpose of this study is to describe our initial clinical experience with dual-energy computed tomography (DECT) virtual non-calcium (VNC) images for the detection of bone marrow (BM) edema in patients with suspected hip fracture following trauma. Twenty-five patients presented to the emergency department at a level 1 trauma center between January 1, 2011 and January 1, 2013 with clinical suspicion of hip fracture and normal radiographs were included. All CT scans were performed on a dual-source, dual-energy CT system. VNC images were generated using prototype software and were compared to regular bone reconstructions by two musculoskeletal radiologists in consensus. Radiological and/or clinical diagnosis of fracture at 30-day follow-up was used as the reference standard. Twenty-one patients were found to have DECT-VNC signs of bone marrow edema. Eighteen of these 21 patients were true positive and three were false positive. A concordant fracture was clearly seen on bone reconstruction images in 15 of the 18 true positive cases. In three cases, DECT-VNC was positive for bone marrow edema where bone reconstruction CT images were negative. Four patients demonstrated no DECT-VNC signs of bone marrow edema: two cases were true negative, two cases were false negative. When compared with the gold standard of hip fracture determined at retrospective follow-up, the sensitivity of DECT-VNC images of the hip was 90 %, specificity was 40 %, positive predictive value was 86 %, and negative predictive value was 50 %. Our initial experience would suggest that DECT-VNC is highly sensitive but poorly specific in the diagnosis of hip fractures in patients with normal radiographs. The value of DECT-VNC primarily lies in its ability to help detect fractures which may be subtle or undetectable on bone reconstruction CT images.

Multimodality imaging features of hereditary multiple exostoses.

Hereditary multiple exostoses (HME) or diaphyseal aclasis is an inherited disorder characterised by the formation of multiple osteochondromas, which are cartilage-capped osseous outgrowths, and the development of associated osseous deformities. Individuals with HME may be asymptomatic or develop clinical symptoms, which prompt imaging studies. Different modalities ranging from plain radiographs to cross-sectional and nuclear medicine imaging studies can be helpful in the diagnosis and detection of complications in HME, including chondrosarcomatous transformation. We review the role and imaging features of these different modalities in HME.

Intravascular embolisation and surgical resection of a giant neurofibroma with intratumoural haemorrhage.

The use of pre-operative embolisation has been described for small neurofibromas, but not for giant lesions. Advances in embolisation techniques are extending the indications for this procedure, in particular to assist with operative intervention on a range of lesions. This case report describes a 45-year-old male with a giant neurofibroma who underwent embolisation to stabilise intratumoural haemorrhage and to assist with haemostasis during the subsequent surgical resection. Minimal transfusion was required and the patient has made a good recovery. This case demonstrates that pre-operative embolisation of these large and challenging lesions is technically feasible and appears to be beneficial in reducing perioperative blood loss and morbidity.

Vertebroplasty for vertebral compression fractures secondary to Cushing's syndrome induced by an ACTH-producing bronchial carcinoid tumour.

Adrenocorticotropic hormone (ACTH)-producing bronchial carcinoid tumours are a rare cause of Cushing's syndrome. Cushing's syndrome is frequently complicated by osteoporosis, which results in an increased tendency for the development of vertebral compression fractures. Percutaneous vertebroplasty has been shown to be an effective treatment option in the setting of painful osteoporotic compression fractures refractory to conservative therapies. We report a case where vertebroplasty was performed on a 36-year-old woman with osteoporosis and compression fractures secondary to hypercorticolism. A bronchial carcinoid tumour was found to be the source of excess ACTH production. Three-level percutaneous vertebroplasty resulted in a marked improvement in pain.

Dual energy computed tomography in tophaceous gout.

OBJECTIVE: To evaluate the potential utility of a dual energy CT (DECT) scan in assessing urate deposits among patients with tophaceous gout, and obtain computerised quantification of tophus volume in peripheral joints. METHODS: 20 consecutive patients with tophaceous gout and 10 control patients with other arthritic conditions were included. DECT scans were performed using a renal stone colour-coding protocol that specifically assessed the chemical composition of the material (ie, urate coloured in red, calcium coloured in blue). An automated volumetric assessment of DECT was used to measure the volume of urate deposits in all peripheral joint areas. RESULTS: All 20 patients with gout showed red colour-coded urate deposits on their DECT scans, whereas none of 10 controls showed urate deposits. DECT scans revealed a total of 440 areas of urate deposition in 20 patients, whereas physical examination showed 111 areas of urate deposition (mean 22 vs 6 per patient, respectively, p<0.001). Total urate volume in a given patient ranged from 0.63 cm(3) to 249.13 cm(3), with a mean of 40.20 cm(3). CONCLUSIONS: DECT scans can produce obvious colour displays for urate deposits and help to identify subclinical tophus deposits. Furthermore, tophus volume can be measured by DECT scans through an automated volume estimation procedure.

Ossifying lipoma of the thigh.

Lipomas are common soft-tissue tumours that are usually found in the subcutaneous adipose tissue. Occasionally, they may contain mesenchymal elements other than adipose tissue, including osseous components. These ossifying lipomas are usually located near or within bone, and it is very rare for a lipoma with no connection to bone to contain mature osseous tissue. We describe a case of a symptomatic ossifying intramuscular lipoma of the thigh.

Aggressive angiomyxoma of the thigh.

Aggressive angiomyxoma is a rare tumour that typically occurs in the perineum in women of reproductive age. A small number of cases occurring in men have been reported, all of which were located in the low pelvis, perineum or scrotum. While benign, the tumour is locally infiltrative and consequently has a high rate of local recurrence following surgery; therefore, accurate pre-operative diagnosis is important. The characteristic location of these tumours in the low pelvis or perineum has led to speculation that aggressive angiomyxomas arise from a mesenchymal cell that is unique to the perineum. We describe a case of aggressive angiomyxoma arising in the thigh of a 54-year-old man, which we believe is the first reported instance of this rare neoplasm occurring remote from the pelvis or perineum in a male patient. Cross-sectional imaging demonstrated a well-defined mass that had low density on CT and high intensity on fluid-sensitive MR sequences. Biopsy was non-diagnostic and excision was performed. At histological analysis, the tumour exhibited the characteristic features of aggressive angiomyxoma, with bland spindle cells and large, hyalinised blood vessels in a hypocellular myxoid matrix. Extensive immunohistochemical staining further supported the diagnosis. While the imaging features of these tumours are non-specific and suggestive of myxoid neoplasms, the diagnosis should be considered whenever biopsy of a myxoid-appearing mass yields hypocellular, non-diagnostic material, despite adequate sampling.

A case report of synchronous osteoblastoma and fibromatosis.

Osteoblastoma is a rare bone tumour that accounts for 1% of all primary bone tumours and 3% of all benign bone tumours. Osteoblastoma occurring in long bones has a predilection for the meta-diaphysis. It bears a close histological resemblance to osteoid osteoma, but it is not growth limited - usually 2 cm or greater at diagnosis. The term "fibromatosis" covers a broad spectrum of benign fibrous tissue proliferations. It is characterized by infiltrative growth and a tendency for recurrence; however, unlike sarcoma, it never metastasizes. To our knowledge, this is the first case report in the English literature of a patient with synchronous presentation of an osteoblastoma and fibromatosis.

Radiological features of synovial cell sarcoma.

Synovial cell sarcoma is an uncommon soft-tissue malignant tumour. These tumours have common radiological features with a variety of both benign and malignant lesions. However, there is a variety of imaging findings that can suggest a pre-biopsy diagnosis of synovial cell sarcoma. This pictorial review aims to describe the imaging features of synovial sarcoma in a series of cases with various age ranges and tumour locations. In addition, the pathology, staging, prognosis and management of synovial sarcoma is briefly discussed.

Radiological imaging features of non-uterine leiomyosarcoma.

Leiomyosarcomas are unusual soft-tissue tumours that occur in the retroperitoneum, peripheral soft tissues, gastrointestinal and genito-urinary tracts, vessels and (rarely) in bone. The aim of this pictonal review is to delineate the more specific radiological features that would suggest a radiological diagnosis of leiomyosarcoma prior to biopsy.

The imaging appearances of metallosis.

Metallosis is an uncommon condition in which there is infiltration of periprosthetic soft tissues and bone by metallic debris resulting from wear of joint arthroplasties. It is often associated with significant osteolysis; therefore the identification of metallosis is an indication for revision arthroplasty. The radiographic, CT and MRI features of metallosis in a 63-year-old man who presented 16 years post-arthroplasty are described in this case report.

Imaging of Budd-Chiari syndrome.

Budd-Chiari syndrome occurs when venous outflow from the liver is obstructed. The obstruction may occur at any point from the hepatic venules to the left atrium. The syndrome most often occurs in patients with underlying thrombotic disorders such as polycythemia rubra vera, paroxysmal nocturnal hemoglobinuria and pregnancy. It may also occur secondary to a variety of tumours, chronic inflammatory diseases and infections. Imaging plays an important role both in establishing the diagnosis of Budd-Chiari syndrome as well as evaluating for underlying causes and complications such as portal hypertension. In this review article, we discuss the role of modern imaging in the evaluation of Budd-Chiari syndrome.

Malignant chest wall neoplasms of bone and cartilage: a pictorial review of CT and MR findings.

Malignant tumours of the chest wall are uncommon. The purpose of this pictorial essay is to describe the CT and MRI findings of malignant neoplasms affecting the bony skeleton of the chest wall and the costal cartilages. The most common primary malignant neoplasms involving the bony skeleton of the chest wall are chondrosarcoma, osteosarcoma and Ewing's sarcoma/primitive neuroectodermal tumour. Metastases, multiple myeloma and invasive primary lung cancer are the most frequent secondary lesions. We performed a retrospective review of the radiology and pathology archive at our institution from 1 July 2000 to 31 December 2004 and identified 31 of these lesions. Several of these tumours have distinctive radiological features, allowing a confident radiological diagnosis to be suggested.

CT-guided bone biopsy: Initial experience with a commercially available hand held Black and Decker drill.

PURPOSE: To describe the use of a simple commercially available Black and Decker hand based drill in performing CT-guided bone biopsies. MATERIALS AND METHODS: Three international institutions were enrolled in the study. In each centre, a fellowship trained musculoskeletal radiologist directed the assessment of a hand based commercial drill for performing CT-guided bone biopsies. A specially designed component was engineered which allowed the connection of a standard bone biopsy set to a commercial drill. The component was distributed to the three centres involved. Over a 3-year period, data from all three institutions was collected. Information regarding technical success, diagnostic data and complication rates were all collated to assess the technical feasibility of this technique. RESULTS: In total 68 patients underwent bone biopsy using a hand held commercial drill. Technical success was achieved in 65 patients. Diagnostic material was obtained in 53 patients. Non-diagnostic material was obtained in 12 patients. Five out of the 12 patients with non-diagnostic material had repeat biopsies with diagnostic material obtained in 2 of these. No major complications occurred in any patient. CONCLUSION: CT-guided bone biopsy using a hand held commercial drill has a technically high success rate with minimal complications.

Soft tissue tumours and mass-like lesions of the chest wall: a pictorial review of CT and MR findings.

Soft tissue tumours and tumour-like lesions of the chest wall are uncommon. The purpose of this pictorial essay is to describe the imaging findings of chest wall soft tissue tumours and tumour-like lesions. We searched the radiological and pathological archive at our institution retrospectively and reviewed the literature on soft tissue tumours of the chest wall. Common chest wall soft tissue tumours and mass-like lesions include peripheral nerve tumours, lipomas, liposarcomas, haemangiomas, elastofibromas, metastases, lymphoma and abscesses. Other lesions encountered include desmoid tumours and malignant fibrous histiocytoma. Many have distinctive radiological findings or occur in specific locations, allowing a specific radiological diagnosis to be suggested.

An unusual case of elevated liver enzymes (2006: 10b). Hepatic necrosis following HELLP syndrome.

HELLP syndrome is a form of severe pre-eclampsia with multisystem involvement. Laboratory markers include haemolysis (H), elevated liver enzymes (EL), and low platelets (LP). We present a patient to our institution with HELLP syndrome complicated by liver necrosis. The patient underwent urgent Caesarian section prior to transfer.