Wasp sting-induced bilateral thalamic and midbrain infarction.

A male patient in his early 40s presented to the emergency department with an acute onset of respiratory distress and facial oedema, indicative of anaphylaxis. These symptoms emerged 2 hours subsequent to a wasp sting on the left side of his face. Despite initial stabilisation, the patient's state deteriorated into somnolence and disorientation. Notably, he denied any history of seizures, sensory or motor deficits, or bowel/bladder complications. Physical examination unveiled no focal neurological deficits. Routine laboratory tests and drug screening yielded no significant findings. Subsequent brain MRI with angiography exposed bilateral thalami diffusion restriction, strongly implying an acute infarction within the artery of Percheron territory, an atypical vascular variant. The sequence of events, alongside the absence of other conclusive aetiologies, indicated a wasp sting-induced thalamic infarction driven by vasogenic and thrombogenic effects of inflammatory substances.

Multi-modality parathyroid imaging: A shifting paradigm.

The goal of parathyroid imaging in hyperparathyroidism is not diagnosis, rather it is the localization of the cause of hyperparathyroidism for planning the best therapeutic approach. Hence, the role of imaging to accurately and precisely localize the abnormal parathyroid tissue is more important than ever to facilitate minimally invasive parathyroidectomy over bilateral neck exploration. The common causes include solitary parathyroid adenoma, multiple parathyroid adenomas, parathyroid hyperplasia and parathyroid carcinoma. It is highly imperative for the radiologist to be cautious of the mimics of parathyroid lesions like thyroid nodules and lymph nodes and be able to differentiate them on imaging. The various imaging modalities available include high resolution ultrasound of the neck, nuclear imaging studies, four-dimensional computed tomography (4D CT) and magnetic resonance imaging. Contrast enhanced ultrasound is a novel technique which has been recently added to the armamentarium to differentiate between parathyroid adenomas and its mimics. Through this review article we wish to review the imaging features of parathyroid lesions on various imaging modalities and present an algorithm to guide their radiological differentiation from mimics.

Technical and Interpretive Pitfalls in Pediatric Musculoskeletal Ultrasound.

The use of musculoskeletal (MSK) ultrasound (US) in pediatric rheumatology has expanded rapidly with various diagnostic and therapeutic indications. Unlike magnetic resonance imaging (MRI), US allows real-time dynamic assessment, evaluation of multiple joints in a single session and comparison with contralateral limb. However, a long learning curve and lack of experience with MSK US in pediatric patients still precludes its routine use at many imaging centers. It is prudent for pediatric radiologists to be aware of normal US appearances of the growing MSK structures to avoid their misinterpretation as pathology. The normal MSK US findings in children which can be confused with pathology and create diagnostic difficulty can arise due to variable states of maturation of bones, cartilage and tendons, complex anatomical locations, accessory structures, and artifacts. Herein, we describe the various technical and interpretive challenges encountered with MSK US in pediatric patients.

Dermatomyositis: Patterns of MRI findings in muscles, fascia and skin of pelvis and thigh.

PURPOSE: This review discusses characteristic, subtle, and florid changes in muscle, fascia, skin, and subcutaneous tissue of the lower limbs in MR imaging in patients with dermatomyositis. MATERIAL AND METHODS: This review is based on the analysis of 43 patients with dermatomyositis who were imaged from January 2014 to March 2021 in our institute as well a critical review of literature of MRI in dermatomyositis. RESULTS: Muscle involvement is predominantly bilaterally symmetric and involves anterior, posterior as well as medial compartments of the thigh. Diffuse intramuscular hyperintensity on T2-weighted images is a common pattern of involvement. Isolated myofascial involvement or muscular with myofascial involvement can also occur. Nodular areas of hyper intensity and enhancement is another uncommon pattern of muscle involvement. Reticular pattern of subcutaneous tissue involvement and skin thickening is best seen on fat saturated T2 -weighted images. Calcification in the subcutaneous tissues appears hypointense with a surrounding hyperintense rim on all pulse sequences which shows peripheral enhancement. MRI patterns of involvement range from subtle myofascial and skin involvement to florid muscular involvement. Diffusion weighted imaging is useful for myofascial involvement. Whole body MR can detect changes at unusual sites in muscles and extra skeletal involvement. Contrast enhanced imaging has no added benefit. Treatment responders show a return to normal signal intensity on MRI. CONCLUSION: This review highlights the patterns of muscle, skin, and subcutaneous tissue involvement of thighs in dermatomyositis on conventional MRI and the role of whole-body MR, diffusion weighted imaging and limited role of contrast enhanced imaging.

Primary elbow osteoarthritis presenting as ulnar nerve palsy with claw hand.

A 59-year-old woman was referred with weakness, paraesthesia, numbness and clawing of the little and ring fingers for the last 2 years. MRI of the cervical spine was normal and nerve conduction velocity revealed abnormality of the ulnar nerve. Ultrasound and MRI showed medial osteophytes and effusion of the elbow joint with stretched and thinned ulnar nerve in the cubital tunnel. The patient underwent release and anterior transposition of the ulnar nerve with significant relief of symptoms.