Imaging of supra-thoracic tuberculosis.

Tuberculosis (TB) typically affects the lungs, but may involve many extra-pulmonary sites; with the latter especially prone in patients with human immunodeficiency virus infection. The clinical features of extra-pulmonary TB are often non-specific, mimicking many different disease entities. Application of the most appropriate imaging modality and knowing the imaging findings with clinical context awareness help initiation of further investigations, diagnosis and early treatment. This pictorial essay highlights the imaging spectrum of extra-pulmonary TB affecting the supra-thoracic region, i.e. brain, neck, and ear, nose and throat.

Benign incidental do-not-touch bone lesions.

Benign bone lesions may occasionally be incidentally detected on radiographs and are also increasingly found on CT or MRI performed for other clinical indications. Although mostly asymptomatic or associated with minor symptoms, these lesions may simulate true pathological lesions, causing problems in diagnosis. For instance, asymptomatic benign bone lesions can be misinterpreted as metastasis when incidentally encountered in a patient with known cancer. Recognising these entities as "do-not-touch" lesions helps avoid unnecessary further investigation or harmful intervention. In this review, we highlight three groups of bone incidentalomas found in adults, namely: osteolytic lesions, osteoblastic lesions, and bone protuberances. We aim to review the key imaging features of selected common and less common conditions in these three groups, so as to help radiologists confidently identify these benign do-not-touch lesions and to distinguish them from more sinister pathological lesions.

Imaging update on musculoskeletal infections.

The clinical diagnosis of musculoskeletal infections can be challenging due to non-specific signs and symptoms on presentation. These infections include infectious myositis, necrotising fasciitis, septic arthritis, septic bursitis, suppurative tenosynovitis, osteomyelitis, spondylodiscitis and periprosthetic infections. Diagnostic imaging is routinely employed as part of the investigative pathway to characterise the underlying infectious disease pattern, allowing expedited and customised patient management plans to optimise outcomes. This article provides an update on the various imaging modalities comprising of radiography, computed tomography, ultrasonography, magnetic resonance imaging and radionuclide procedures, and incorporates representative images of key findings in the different forms of musculoskeletal infections.

Acromioclavicular joint injuries: Imaging and management.

Acromioclavicular joint injuries are commonly encountered in the setting of shoulder trauma. Knowledge of the anatomy and biomechanics of the joint, grading of joint injuries, and understanding the capabilities and limitations of different radiological modalities will help in selecting the best management option and outcomes for affected patients.

Imaging of intramuscular haemangiomas of the extremities.

Intramuscular haemangiomas are benign soft tissue tumours that are more frequently seen in children and young adults. As they may be difficult to diagnose clinically, imaging has an important role in the detection, diagnosis and preoperative planning of these lesions. Haemangiomas of the extremities may be classified into capillary, cavernous, venous and mixed types, with or without an arteriovenous shunt, depending on the predominant vascular channels. Nonvascular components such as fat, smooth muscle, fibrous tissue and thrombus may also be present. This pictorial essay highlights the imaging features of intramuscular haemangiomas, with an emphasis on magnetic resonance imaging.

Magnetic resonance imaging of cervical ligamentous anatomy and traumatic ligamentous injuries.

Cervical spine trauma accounts for majority of spinal injuries, and approximately one-third involve the craniocervical junction (CCJ). Due to its high sensitivity, magnetic resonance imaging (MRI) has become the standard tool for imaging suspected ligamentous injuries in an unstable spine and in patients with neurological deficits having a normal CT. The ligamentous anatomy of the CCJ is complex, and thorough knowledge is a prerequisite for accurate interpretation of the MRI findings. This pictorial essay aims to familiarise radiologists with the ligamentous anatomy, mechanisms of injury and MRI appearances of injuries in the cervical spine, with emphasis on the CCJ.

Clinics in diagnostic imaging (189). Acute phase cardiac sarcoidosis (CS).

A 44-year-old man presented with breathlessness and episodes of palpitations for the last one year. The imaging diagnosis of cardiac sarcoidosis was made based on chest radiography and cardiac magnetic resonance (MR) imaging findings, and was further confirmed by biopsy. Cardiac sarcoidosis is an uncommon entity, yet is potentially fatal with nonspecific clinical manifestations, including sudden cardiac death. Hence, it is important to diagnose and treat this entity at an early stage to improve morbidity and mortality. Cardiac MR imaging plays a pivotal role in facilitating diagnosis and monitoring therapeutic response. We describe the MR imaging features of cardiac sarcoidosis and discuss imaging features of other cardiomyopathies that may mimic cardiac sarcoidosis.

Clinics in diagnostic imaging (184). Fat embolism syndrome (FES).

A 23-year-old Indian man presented with shortness of breath and new-onset confusion along with a rash on his chest on Postoperative Day 2, following internal fixation of his femur fracture. Although computed tomography pulmonary angiography was negative for filling defects in the pulmonary vasculature, it showed mosaic attenuation changes with some interlobular septal thickening. Magnetic resonance imaging of the brain showed patchy signal abnormalities, predominantly in the grey-white matter junction region with extensive susceptibility artefacts, consistent with petechial haemorrhages. The laboratory work-up showed thrombocytopenia and anaemia. A diagnosis of fat embolism syndrome was established, based on the clinical presentation combined with laboratory and imaging findings. The clinical and imaging features of fat embolism syndrome are discussed.

Clinics in diagnostic imaging (178). Wünderlich syndrome and pseudoaneurysm.

Wünderlich syndrome is a rare entity characterised by spontaneous retroperitoneal haemorrhage with renal origin. We present a case of Wünderlich syndrome secondary to clotting dyscrasia in a 64-year-old woman. The patient experienced a second Wünderlich haemorrhagic event with metachronous pseudoaneurysm formation, which was likely secondary to the large subcapsular haematoma stripping the renal capsule and tearing the cortical arteries. Selective pseudoaneurysm embolisations were successfully performed on both occasions. This clinical entity, its imaging differential diagnoses and management are discussed.

Magnetic resonance imaging of painful swollen legs in the emergency department: a pictorial essay.

Patients presenting with a painful swollen leg are not infrequently encountered at the emergency department and can pose a diagnostic dilemma for attending physicians. The potential causes of leg pain and swelling include trauma, infection, inflammation, and neurogenic, vascular, and iatrogenic conditions; with magnetic resonance imaging (MRI) being an important tool in evaluation. We describe the MRI features of various conditions causing painful swollen legs. We also discuss the differential diagnosis and the useful clinical and laboratory findings that radiologists should be aware of, in order to arrive at an accurate diagnosis.

Clinics in diagnostic imaging (175). Corpus callosum glioblastoma multiforme (GBM): butterfly glioma.

A 54-year-old man presented with change in behaviour, nocturnal enuresis, abnormal limb movement and headache of one week's duration. The diagnosis of butterfly glioma (glioblastoma multiforme) was made based on imaging characteristics and was further confirmed by biopsy findings. As the corpus callosum is usually resistant to infiltration by tumours, a mass that involves and crosses the corpus callosum is suggestive of an aggressive neoplasm. Other neoplastic and non-neoplastic conditions that may involve the corpus callosum and mimic a butterfly glioma, as well as associated imaging features, are discussed.

Clinics in diagnostic imaging (174). L5 vertebral superior facet osteoblastoma (OB).

A 25-year-old man presented with chronic low back pain and occasional radiation to the right lower limb. Magnetic resonance imaging and computed tomography (CT) of the lumbar spine showed an osteolytic expansile lesion with a central sclerotic nidus in the right superior facet of the L5 vertebra and surrounding marrow oedema. The diagnosis of osteoblastoma was made based on imaging findings and confirmed after CT-guided biopsy. Radiofrequency ablation of the lesion was successfully performed. The patient tolerated the procedure well and showed symptomatic relief. The imaging features and management of osteoblastoma are discussed.

Clinics in diagnostic imaging (173). Scimitar syndrome with horseshoe lung.

A 56-year-old Chinese man presented with giddiness and vertigo. Subsequent chest radiography showed the classic scimitar sign of an abnormal pulmonary venous return. Further evaluation with non-contrast computed tomography substantiated the finding of a partial anomalous venous drainage pattern and identified an associated rare lung anomaly, horseshoe lung. The imaging findings of scimitar syndrome and its association with horseshoe lung are reviewed.

Vomiting-induced short gastric artery apoplexy.

Abdominal apoplexy due to short gastric artery rupture following vomiting is an exceedingly rare condition. It results from non-traumatic and non-iatrogenic causes. This entity has variable clinical presentation and patients usually present with non-specific abdominal pain. Imaging plays a vital role in early diagnosis, as immediate exploratory laparotomy is the treatment of choice for successful outcome and helps to reduce mortality rate. We report the case of a 27-year-old male patient who presented to the emergency department with acute-onset abdominal pain after multiple episodes of vomiting following binge alcohol drinking. Contrast-enhanced CT revealed intraperitoneal haemorrhage secondary to vessel rupture, probably from a short gastric artery. Intraoperatively, the short gastric artery was identified as the bleeding source and ligated. The patient had an uneventful postoperative course.

Magnetic resonance imaging of traumatic and non-traumatic brachial plexopathies.

Adult-onset brachial plexopathy can be classified into traumatic and non-traumatic aetiologies. Traumatic brachial plexopathies can affect the pre- or postganglionic segments of the plexus. Non-traumatic brachial plexopathies may be due to neoplasia, radiotherapy, thoracic outlet syndrome and idiopathic neuralgic amyotrophy. Conventional magnetic resonance imaging (MRI) is useful to localise the area of injury or disease, and identify the likely cause. This review discusses some of the common causes of adult-onset brachial plexopathy and their imaging features on MRI. We also present a series of cases to illustrate some of these causes and their MRI findings.