Radiofrequency Ablation (RFA) Monopolar RFA involves the application of high frequency (460-500 kHz) alternating current to the target tissue using a needle like applicator (dispersive grounding pads are attached to the patient's trunk / thigh) ► the resultant alternating electric field…
Chest Pleural drainage catheters are smaller than surgical drains (up to 16Fr) – haemothorax is better treated with surgical drains (36–38Fr) USS is adequate for uncomplicated collections, but CT is usually needed for drainage of multiloculated pleural collections It is…
Multidetector CT Angiography (MDCTA) Rapid IV injection of contrast (3-5 mL/s) ▸ automated contrast bolus detection techniques: the ‘arrival of contrast medium is measured within a vessel at a single level, and data acquisition initiated when a certain density threshold is…
Catheter Angiography Vascular Access Contraindications Very few absolute contra-indications – caution with patients on anticoagulants / systemic hypertension / prolonged steroid treatment / connective tissue disorders The right common femoral arterial approach is preferred (other sites include the axillary, brachial…
Positron Emission Tomography – CT (PET-CT) General principles PET imaging is based on the detection of an injected positron-emitting radioactive tracer – PET relies on the co-incidence detection of the annihilation photons (γ) released when a positron combines with an…
9 Lymphoma 894 Introduction 894 Lymph node disease in lymphoma 898 CNS lymphoma 900 Pulmonary lymphoma 902 Lymphoma of the gastrointestinal tract 904 Musculoskeletal lymphoma 906 Extranodal manifestations of lymphoma 908 Monitoring the response to therapy in lymphoma 912 Lymphoma…
Non-Functional Adrenal Disorders Non-Hyperfunctioning Adrenal Adenoma Definition This is due to non-neoplastic overgrowth of the adrenocortical cells of the zona fasciculate More common in some inherited diseases (e.g. MEN 1/Beckwith–Weidman syndrome/Carney complex) It is detected incidentally in up to 5%…
Thyroid Cancer Thyroid Cancer Definition A malignant tumour arising from the thyroid or parafollicular C cells ▸ it is an uncommon tumour (accounting for 0.5% of all cancer deaths) Risk factors: previous radiation exposure ▸ iodine excess ▸ a genetic…
Mandibular/Maxillary Cystic Lesions General Features Definition Cysts occur more frequently within the jaw than in any other bone due to the numerous epithelial cell residues left after tooth formation ▸ these cysts are slow growing and painless (unless they become…
Selected Disorders of the Ear External Ear Squamous or basal cell carcinoma HRCT Defines the extent of any bone erosion or destruction MRI Allows precise assessment of the soft tissue mass Necrotizing otitis externa Definition An osteomyelitis/necrosis particularly affecting the…