Spinal Dysraphism Spinal Dysraphism Definition This is also known as a neural tube defect (NTD), and are a group of congenital spine abnormalities that may cause progressive neurological damage (affecting 1 : 1000 live births) The common feature is an anomaly of the midline structures of the back It results from incomplete midline closure of the bony and neural spinal tissues following defective primary neural tube closure and…

Cerebellar Malformations Cerebellar Hypoplasia Definition The cerebellum may be small due to a congenital lack of formation or from subsequent atrophy ■ Causes: infection (especially congenital cytomegalovirus) ▸ inborn errors of metabolism (e.g. glycolysation disorder) ■ Other rarer causes: carbohydrate-deficient glycoprotein syndrome ▸ infantile neuroaxonal dystrophy ▸ pontocerebellar hypoplasia ▸ spinocerebellar atrophies ▸ Friedreich's ataxia Clinical presentation Variable hypotonia or ataxia Radiological features MRI Symmetrical atrophy…

Head Injury Subdural Haemorrhage (SDH) Definition Traumatic bleeding between the dura mater and arachnoid mater ▸ it usually arises from rupture of the veins crossing the subdural space (vault fractures are an uncommon cause) ▸ often associated with brain damage These may be extensive – although the haemorrhage is of low pressure, the blood is unrestricted and can spread over the entire brain surface ▪ Acute:…

Intracranial Infection Brain Abscess Definition A focal encapsulated pus-containing cavity ▸ in immunocompetent patients it is usually due to a streptococcal bacterial infection (multiple in 10–50%) ▪ It usually arises by haematogenous dissemination ▸ it can also occur following penetrating trauma or due to direct spread from a contiguous infection ▪ Fungal cerebral abscesses: these typically affect immunocompromised patients ▸ they are similar to a pyogenic…

Cerebral Ischaemia Cerebral Ischaemia Definition Stroke A sudden persistent neurological deficit of vascular origin Causes Large vessel thromboembolic stroke (40%) Most commonly due to thrombus at the site of atherosclerotic plaque or embolization more distally ▸ sites: carotid bifurcation > intracranial internal carotid artery (ICA) > proximal MCA (> anterior cerebral artery (ACA)) ▸ vertebral artery origins > distal vertebral artery (VA) > basilar artery Vasculopathy…

Imaging Techniques and General Features Computed Tomography NECT Intra-axial tumours: usually of low attenuation on NECT ▸ high attenuation areas within a tumour indicate tumour calcification or recent intratumoural haemorrhage Extra-axial tumours: associated with bone erosion or hyperostosis CECT Improved visualization of an enhancing mass lesion (e.g. a meningioma or metastases) CT perfusion This can assess tumour relative cerebral blood volume (rCBV) and permeability changes ▸…

Imaging Techniques in Gynaecology Ultrasound (US) Indications Evaluation of a pelvic mass, uterine enlargement, endometrial abnormalities, ovarian masses or acute pelvic pain ▸ it allows transabdominal and transvaginal guidance of fluid or tissue sampling ▸ it allows transvaginal-guided drain placement and guidance for placement of brachytherapy for cervical and endometrial malignancy ▸ it allows intraoperative assessment for the completion of evacuation of products of conception Transabdominal…

Introduction Normal Anatomy The breast lies on the chest wall and on the deep pectoral fascia ▸ the superficial pectoral fascia envelops the breast ▸ suspensory ligaments (Cooper's ligaments) connect the two layers 2 components Nipple–areolar complex: ▪ Collecting ducts open onto the tip of the nipple ▪ Sebaceous glands within the nipple–areolar complex are called Montgomery's glands ▸ ducts open onto the skin surface (and…

Reticuloendothelial Disorders Langerhans Cell Histiocytosis Definition A non-neoplastic proliferation of Langerhans cells Letterer–Siwe disease (acute disseminated histiocytosis) Rare and usually fatal ▸ it affects children <2 years of age ▸ splenomegaly, hepatomegaly and lymphadenopathy with anaemia predominate (patients usually die before any bone lesions are identified) ▸ patients present with fever and a failure to thrive Hand–Schüller–Christian disease (chronic multifocal histiocytosis) A disorder of childhood ▸…

Developmental Skeletal Anomalies Osteochondrodysplasias These are classified into 33 groups (1–33) ▸ abnormalities are intrinsic to bone and cartilage and will continue to evolve throughout life ■ Dysplasias: abnormalities of bone ± cartilage growth ■ Osteodystrophies: abnormalities of bone ± cartilage texture Conditions referenced elsewhere ■ Group 25 (dysplasia with increased bone density) – Osteogenesis imperfecta (Section 5 Chapter 7 , Osteogenesis imperfecta) ■ Group 31…

Acute Osteomyelitis Acute Osteomyelitis Definition Acute infection of the bone diagnosed within 2 weeks of symptoms (subacute if diagnosed > 2 weeks) ▸ causes: ▪ Staphylococcus aureus : commonest organism in any age group (80%) ▪ Gram-negative organisms ( Pseudomonas/Enterobacter ): remaining 20% ▪ Acute infections prosthetic implants: S. aureus Spontaneous MSK infections in adults are less common than in children and are usually die to…

Introduction Clinical and Radiological Findings in Joint Disease Condition Site of involvement Discriminatory findings Primary osteoarthritis (F>M ▸ > 45 years) Hands PIP and DIP joint involvement (Heberden's and Bouchard's nodes) ▸ no osteopenia Large joints (e.g. hip, knee) Joint space narrowing ▸ subchondral sclerosis ▸ subchondral cysts ▸ marginal osteophytes Spine Degenerative disc disease ▸ spondylosis deformans ▸ apophyseal joint involvement ▸ spinal stenosis ▸…

Osteoporosis Osteoporosis Definition A systemic skeletal disease characterized by a low bone mass and micro-architectural deterioration of the bone tissue with a consequent increase in bone fragility and an associated susceptibility to fracture It is the most common metabolic disorder affecting 50% of woman and 20% of men (> 50 years old) ▸ due to: ▪ Reduced bone accumulation during development ▪ Bone resorption outstrips new…

Chondroid Origin Chondrosarcoma Definition A malignant cartilage-producing tumour – it generally has a better prognosis than an osteosarcoma (due to late metastases) Classification: ▪ Central (intramedullary) vs peripheral ▪ Primary vs secondary (e.g. arising in a pre-existing bone lesion such as a central enchondroma or a peripheral osteochondroma) ▪ Grade I: low grade ▸ Grade II: myxoid ▸ Grade III: high grade ▸ dedifferentiated: this refers…

Chondroid Origin (En)Chondroma Definition Chondroma: a benign intramedullary neoplasm consisting of mature hyaline cartilage ▸ it is commonly centrally located (and then referred to as an enchondroma) It is the 2 nd commonest benign chondral lesion (after an osteochondroma) Clinical Presentation An incidental finding ▸ a pathological fracture (60%) ▸ pain in the absence of a fracture or a rapid size increase is potentially malignant Age:…

General Characteristics of Bone Tumours Age at Presentation Metastases are the commonest malignant bone tumours in patients that are > 45 years of age (an atypical metastasis is more common in this age group than a classical primary malignant tumour) ▪ Primary malignant bone tumours are rare before 5 years of age ▪ 1 st decade: these are commonly disseminated bone lesions of leukaemia and neuroblastoma…

Localized Calcification and Ossification Localized Calcification and Ossification Definition Deposition of calcium pyrophosphate dihydrate or calcium hydroxyapatite within soft tissues is called mineralization or calcification Metastatic: the result of abnormal calcium metabolism Calcinosis: occurring with a normal calcium metabolism Dystrophic: related to tissue damage Ossification: bony trabeculae are discernible (either ectopic or heterotropic) ▸ calcium deposits tend to be more densely sclerotic than in normal bone…

Specific Paediatric Fractures Greenstick/Torus Fracture/Plastic Bowing Definition In the paediatric skeleton the soft bone tends to bend and partially break (greater elasticity) Greenstick fracture: the bone cortex and periosteum break on the convex side of a long bone only Torus fracture: the bone cortex buckles on the concave side Plastic bowing: a long bone bends, rather than breaks (multiple oblique microfractures are present) ▸ in the…

Introduction General Considerations XR Two orthogonal views are required ▸ it is poor at soft tissue assessment Displacement and obliteration of the normal fat pads can be a clue to an acute fracture haematoma or joint distension ▸ a lipohaemarthrosis (fat and blood within the joint space) is evidence of an intra-articular fracture Scintigraphy Uptake is related to any osteoblastic activity ▸ it is much more…

Duplex Kidney Duplex Kidney Definition A congenital abnormality where drainage of the kidney is via two collecting systems (occurring in 3% of individuals) ▪ Partial < complete ▪ Bilateral > unilateral Complete duplication ▪ The ureters draining the two moieties never join ▪ Classically the upper moiety ureter obstructs (its ectopic ureteral orifice is often stenotic) and the lower moiety ureter tends to demonstrate vesicoureteric reflux…