@About this App@Contributers@DeveloperACTH (Adrenocorticotropic hormone)AFP (Alpha-fetoprotein) TestingAIDS Dementia Complex (HIV)AIDS HIV InfectionAPGAR Scoring (Children)APTT and CoagulationAbacavirAbataceptAbbreviated Mental Test Score (AMTS)AbciximabAbdominal Aortic AneurysmAbdominal paracentesis for ascitesAbducent NerveAbetalipoproteinaemiaAbnormal Vaginal bleedingAcamprosateAcanthocytosisAcanthosis NigricansAcarboseAccelerated Idioventricular RhythmAcetazolamideAcetylcholine Receptor AntibodiesAcetylcholinesterase inhibitorsAchalasiaAchilles Tendon ruptureAchondroplasia (Children)AciclovirAcid maltase deficiency (Pompe disease)Acne RosaceaAcne VulgarisAcoustic Neuroma (Schwannoma)Acrodermatitis enteropathica (Children)Acromegaly and GiantismAcromio-clavicular jointActinomyces israeliAction PotentialActivated CharcoalActrapid (Insulin)Acute Abdominal Pain - Acute PeritonitisAcute Acalculous CholecystitisAcute Anaphylactoid ReactionsAcute AnaphylaxisAcute Angle Closure GlaucomaAcute AppendicitisAcute Bacterial MeningitisAcute BronchitisAcute CholangitisAcute CholecystitisAcute Colonic Pseudo-obstructionAcute Coronary Syndrome (ACS) GeneralAcute Coronary Syndrome (ACS) NSTEMI USAAcute Coronary Syndrome (ACS) STEMIAcute Coronary Syndrome (Cardiac Troponins)Acute Coronary Syndrome Grace scoreAcute DeliriumAcute Disc lesionsAcute Disseminated EncephalomyelitisAcute Diverticulitis - Diverticular diseaseAcute Dystonic ReactionAcute EncephalitisAcute Eosinophilic PneumoniaAcute EpiglottitisAcute Exacerbation of COPDAcute HepatitisAcute HydrocephalusAcute HypotensionAcute InflammationAcute Intermittent Porphyria (AIP)Acute Interstitial nephritisAcute Kidney Injury (AKI)Acute Limb IschaemiaAcute Liver FailureAcute Lymphoblastic Leukaemia (ALL)Acute MastoiditisAcute MonoarthritisAcute Myeloid Leukaemia (AML)Acute MyocarditisAcute PancreatitisAcute Pelvic Inflammatory DiseaseAcute PericarditisAcute Phase reactantsAcute PorphyriasAcute Promyelocytic LeukaemiaAcute Respiratory Distress Syndrome (Adults)Acute Retroviral Syndrome (HIV)Acute RhabdomyolysisAcute Rheumatic feverAcute Rotator cuff tearAcute Severe AsthmaAcute Severe ColitisAcute SinusitisAcute Stroke Assessment (ROSIER&NIHSS)Acute TonsilitisAcute Urinary RetentionAcute and Chronic GoutAcute and Chronic Heart FailureAcute on Chronic Liver Disease DecompensationAcutely Ill PatientAdalimumabAddenbrooke's Cognitive Examination-Revised (ACER)Addison Disease (Adrenal Insufficiency)AdefovirAdenosineAdenosine deaminase deficiencyAdhesive Capsulitis (Frozen Shoulder)Adjustment - Anxiety disordersAdrenal AntibodiesAdrenal PhysiologyAdrenaline (Epinephrine)AdrenoleukodystrophyAdrenomyeloneuropathyAdult Onset Still's DiseaseAfrican Trypanosomiasis (Sleeping sickness)Age related macular degenerationAicardi syndromeAir EmbolismAlbuminAlbumin-Protein Creatinine Ratio (PCR)Alcohol AbuseAlcohol Withdrawal (Delirium Tremens)Alcoholic (Steato)HepatitisAlcoholic KetoacidosisAldosterone PhysiologyAlendronate (Alendronic acid)AlfacalcidolAlkaline phosphatase (ALP)Alkalinisation of urineAlkaptonuriaAllergic Bronchopulmonary AspergillosisAllogeneic stem cell transplantationAllopurinolAlogliptin (Vipidia)AlopeciaAlpha FetoproteinAlpha ThalassaemiaAlpha subunit (ASU) of TSHAlpha-1 Antitrypsin (AAT) deficiencyAlport's SyndromeAlteplaseAltitude sicknessAluminium and Magnesium AntacidsAlveolar Gas EquationAlzheimer disease (Dementia)AmantadineAmenorrhoeaAmerican Trypanosomiasis (Chagas Disease)AmilorideAmino acidsAminoglycosidesAminophyllineAminosalicylatesAmiodaroneAmiodarone and Thyroid diseaseAmitriptylineAmlodipineAmmonia EncephalopathyAmnestic syndromesAmoebiasis (Entamoeba histolytica)AmoxicillinAmphetamine toxicityAmphotericin BAmpicillinAnaemia of Chronic DiseaseAnagrelideAnakinraAnal CancerAndexanet alfaAndrogen insensitivity syndromeAneurysmsAngina bullosa haemorrhagicaAngiodysplasiaAngiomyolipomaAngioneurotic OedemaAngiotensin Converting Enzyme InhibitorsAngiotensin Converting enzyme (ACE)Angular Stomatitis - CheilitisAnion GapAnkle and Foot fractures and InjuriesAnkle-Brachial pressure Index (ABPI)Ankylosing spondylitisAnorexia NervosaAntacid medicationAntepartum haemorrhageAnterior Horn Cell diseasesAnterior circulationAnti Dementia DrugsAnti-Cyclic Citrullinated Peptide (CCP) AntibodyAnti-D immunoglobulinAnti-Hu antibodiesAnti-OKT3 antibodiesAnti-RNP AntibodyAnti-Yo antibodiesAnti-neutrophilic cytoplasmic antibodies (ANCA)Antibiotics for Abdominal InfectionsAnticholinergic BurdenAnticholinergic syndromeAnticipationAnticoagulation and AntithromboticsAntidiuretic hormone (Vasopressin)Antigen presenting cellsAntimicrobial ChoicesAntimuscarinic drugsAntiphospholipid syndromeAntithrombin III deficiency (AT3)Aorta anatomyAortic DissectionAortic Regurgitation (Incompetence)Aortic SclerosisAortic StenosisAortoenteric fistulaApathetic thyrotoxicosisApixabanAplastic anaemiaApomorphineAppendix Cancer TumoursApproach to Assessing Sick ChildApproach to child with Acute GastroenteritisApproach to child with respiratory DistressArnold Chiari malformationArrhythmogenic Right ventricular CardiomyopathyArtemisininsArterial Blood gas analysisArterial Pulse assessmentArterial blood gas samplingArterial vs Venous vs Other Leg UlcersArteriovenous malformationsArtery of Percheron strokeArtery-to-artery embolic strokeArtesunateAsbestos Related Lung diseaseAscites Assessment and ManagementAspergillomaAspergillus fumigatusAspirinAspirin Salicylates toxicityAssessing Abdominal PainAssessing BreathlessnessAssessing Chest PainAssessing FallsAsteatotic eczemaAsthmaAstigmatismAstrocytomasAsystoleAtaxia TelangiectasiaAtazanavirAtenololAtherosclerosisAtopic Eczema or Atopic DermatitisAtorvastatinAtracuriumAtrial Ectopic beatsAtrial Fibrillation (Chemical cardioversion)Atrial Natriuretic Peptide (ANP)Atrial fibrillation (AF)Atrial flutterAtrial myxomaAtrial septal defect (ASD)Atrioventricular nodal reentrant tachycardiaAtropine SulfateAutoantibodiesAutoimmune Haemolytic anaemia (AIHA)Autoimmune HepatitisAutonomic neuropathyAutosomal DominantAutosomal Dominant Polycystic kidney diseaseAutosomal RecessiveAzathioprineAzithromycinB lymphocytesBRCA genes (Familial Breast Cancer)Bacillus anthracisBacillus cereus poisoningBackpain / BackacheBaclofenBacteriaBacteroides fragilisBalanitis (Adults)Balanitis (Children)Balkan endemic nephropathy (BEN)Balsalazide (Aminosalicylate)Barrett's oesophagusBartonellaBartters syndromeBasal Cell Carcinoma (BCC)Basic Fracture managementBasilar artery thrombosisBecker Muscular dystrophyBeclometasoneBeer PotomaniaBehavioural and Psychological Symptoms of DementiaBehcet's syndromeBell's palsyBendroflumethiazide (Bendrofluazide)Benign Paroxysmal Positional Vertigo (BPPV)Benign Prostatic HyperplasiaBenign recurrent intrahepatic cholestasisBenzodiazepine ToxicityBenzodiazepinesBenzylpenicillin Sodium (Penicillin G)Berg Balance ScaleBeriplexBerylliosisBeta AgonistsBeta Blocker toxicityBeta ThalassaemiaBeta-2 MicroglobulinBeta-lactamasesBetahistine (Serc)BezafibrateBiceps ruptureBilateral adrenalectomyBiliary atresiaBilirubinBiochemical Lab valuesBisacodylBisoprololBisphosphonatesBladder CancerBladder StonesBleedingBleeding disordersBleeding due to DrugsBleomycinBlindness - global causesBlood products - Packed cells blood transfusionBlood Products - CryoprecipitateBlood Products - Fresh Frozen PlasmaBlood Products - PlateletsBlood film interpretationBlood gas valuesBloody DiarrhoeaBlotting Techniques: Gel ElectrophoresisBone Marrow TransplantationBone disease Lab resultsBone metabolism RANK RANKL OPG pathwayBone scintigraphy (Bone scan)Bordetella pertussis - Whooping coughBorrelia burgdorferiBorrelia recurrentisBotulismBrachial neuritis (neuralgic amyotrophy)Brachial plexus anatomyBrachial plexus and associated injuryBrain AbscessBrain Anatomy and functionBrain MRIBrain Natriuretic Peptide (BNP)Brain PhysiologyBrain Tumours (Cancer)Brainstem anatomyBranchial cleft cystBreast CancerBreast FibroadenomaBretyliumBroad complex TachycardiaBromocriptineBronchial adenomaBronchiectasisBronchiolitisBronchoscopyBrown-Sequard syndromeBrucellaBrugada syndromeBudd-Chiari syndromeBudesonideBuerger disease (Thromboangiitis obliterans )Bulbar vs Pseudobulbar palsyBulimia NervosaBullous PemphigoidBumetanideBunionsBuprenorphineBupropionBurkholderia cepaciaBurkitt's lymphomaBurnsBusulphan (Busulfan)ByssinosisC reactive protein (CRP)CADASILCARASILCHADS2 - CHA2DS2-VASc scoreCMV retinitisCNS fungal InfectionsCNS infectionsCSF RhinorrhoeaCT Head Basics (Stroke)CT Pulmonary angiogram (CTPA)CT imaging basics for StrokeCURB 65 scoreCabergolineCaecal VolvulusCaisson Disease - Decompression sicknessCalcitoninCalcitriol (1,25 Dihydroxycholecalciferol)Calcium Chloride or GluconateCalcium PhysiologyCalcium Pyrophosphate Deposition (Pseudogout)Calcium ResoniumCalcium channel blockers toxicityCalot's triangleCampylobacterCancer of Unknown PrimarCandesartanCandidiasisCannabis toxicityCapecitabineCapnocytophaga canimorsusCapnographyCapreomycinCaptopriCarbamazepineCarbapenemase-producing EnterobacteriaceaeCarbimazoleCarbon monoxide poisoningCarcinoembryonic antigen (CEA)Carcinoid Heart DiseaseCarcinoid Tumour SyndromeCarcinoma of the Bile DuctCarcinoma of the GallbladderCardiac Amyloid heart diseaseCardiac Anatomy and PhysiologyCardiac Catheter ablationCardiac InfectionsCardiac MRICardiac Resynchronisation Therapy (CRT) PacemakerCardiac Valve replacementCardioembolic strokeCardiogenic Pulmonary OedemaCardiogenic shockCardiology - History TakingCardiology Exam ListCardiology ExaminationCardiology Valves SummaryCardiopulmonary bypassCarmustineCarotid Artery anatomyCarotid Body TumourCarotid EndarterectomyCarotid Sinus SyncopeCarotid StentingCarotid artery DissectionCarotid sinus massageCarpal tunnel syndromeCarvedilolCase 01 Sudden weaknessCase 02 Loss of speechCase 03 Adult male weak legsCase 04 High calciumCase 05 High Potassium and heart failureCase 06 High calcium and weight lossCase 07 Weak eyesCase 08 Weak faceCase 09 A cause of DeliriumCase 10 Older patient presenting post strokeCase 11 Young patient with acute headacheCase 20 Young patient with acute headacheCase 21 HypoglycaemiaCase 22Case 23 Old man with tremorCase 24 Cancer and weakCase 99 (Acute breathlessness)Case TemplateCat Scratch DiseaseCataractCatheter Related Urinary Tract infection UTICatheter related Blood stream infectionCatheter related UTICauda equina syndromeCaudate NucleusCauses of Airway ObstructionCauses of Avascular Necrosis of Femoral headCauses of Sore throatCauses of WeaknessCavernous angiomas (Cavernomas)Cavernous sinusCavernous sinus thrombosisCefaclorCefalexinCefotaximeCeftazidimeCeftriaxoneCefuroximeCelecoxibCell Response to InjuryCellular Anatomy and PhysiologyCellulitisCentral Cord SyndromeCentral Retinal Vein Occlusion (CRVO)Central Retinal artery Occlusion (CRAO)Central Venous line InsertionCentral pontine myelinolysisCephalosporinsCerebellar Anatomy Physiology Signs DiseaseCerebellar HaemorrhageCerebellar StrokeCerebral Amyloid angiopathy (CAA)Cerebral AneurysmsCerebral AngiitisCerebral Atrophy vs HydrocephalusCerebral CortexCerebral MetastasesCerebral PalsyCerebral PerfusionCerebral Salt WastingCerebral Venous Sinus thrombosisCerebral arteritisCerebral microbleedsCervical Cancer screeningCervical Spine injuryCervical cancerCervical spondylosisCetirizineChancroidCharcot Foot Syndrome (CFS)Charcot Marie Tooth (CMT) diseaseChediak Higashi syndromeChest Abdomen anatomyChest X Ray #1Chest X Ray InterpretationChest drain InsertionChlamydia - Chlamydophila pneumoniaeChlamydia psittaciChlamydia trachomatisChlorambucilChloramphenicolChlordiazepoxideChloroquineChlorphenamine(Chlorpheniramine)ChlorpromazineCholangiocarcinomaCholera (Vibrio cholera)Cholestatic JaundiceCholesteatomaCholesterol - LipidsCholinergic crisis-syndromeChondrocalcinosisChorea - BallismusChoreoacanthocytosisChromosome instability syndromesChronic BronchitisChronic HepatitisChronic InflammationChronic Inflammatory Demyelinating polyneuropathyChronic Interstitial NephritisChronic Kidney Disease (CKD)Chronic Lymphocytic leukaemia (CLL)Chronic Myeloid Leukaemia (CML)Chronic Obstructive Pulmonary Disease (COPD)Chronic PancreatitisChronic PeritonitisChronic Radiation EnteritisChronic Urinary RetentionChronic Vision Uni-Bilateral loss (Blindness)Chronic and recurrent MeningitisChronic liver diseaseChronic mucocutaneous candidiasisChronic stable anginaChylomicronsCiclosporinCimetidineCinacalcetCiprofloxacinCirrhosisCisplatinCitalopramCladribineClarithromycinCleft lip or palateClindamycinClopidogrelClostridium botulinumClostridium difficileClostridium perfringensClostridium tetani - TetanusClotrimazole creamClotting pathwaysClozapineCo Careldopa (Sinemet)Co-Amoxiclav (Augmentin)Co-Beneldopa (Madopar)Co-codamolCo-trimoxazoleCoagulopathyCoal Worker's PneumoconiosisCoarctation of the Aorta (CoA aortopathy)Cocaine abuseCocaine induced chest painCocaine toxicityCoccidioidomycosisCodeineCoeliac diseaseCogan SyndromeColchicineCold Agglutinin Disease (CAD/AIHA)CollagenColloid cyst in the third ventricleColloidsColonic (Large bowel) ObstructionColonoscopyColorectal cancerColorectal polypsColposcopyComa managementCombined Oral contraceptive pill (COCP)Common Peroneal Nerve (CPN)Common variable immunodeficiencyComparing Rheumatoid and OsteoarthritisComplementComprehensive Geriatric Assessment (CGA)Confirming DeathCongenital Acyanotic Heart Disease (Children)Congenital Adrenal hyperplasiaCongenital Complete Heart BlockCongenital Cyanotic Heart Disease (Children)Congenital HypothyroidismCongenital Talipes Equinovarus - ClubfootConstipationConstrictive PericarditisContact allergic dermatitisContinuous Positive Airways Pressure (CPAP)Continuous ambulatory peritoneal dialysisContraceptionConus Medullaris syndromeCor PulmonaleCoronary artery bypass graft surgeryCoronavirus SARS-CoV-2 COVID 19Corticobasal degeneration (Dementia)Corticosteroid-related psychosisCorticosteroidsCorynebacterium diphtheriaeCotard delusionCoxiella BurnetiiCranial nerves and examinationCraniopharyngiomaCreatinine ClearanceCremation forms (UK)Creutzfeldt Jakob disease (Dementia)Crimean-Congo haemorrhagic feverCritical illness neuromuscular weaknessCrohn's diseaseCroupCryptococcus neoformans infectionsCryptogenic Fibrosing AlveolitisCryptogenic Organising Pneumonia (COP-BOOP)CryptosporidiosisCrysal arthritisCrystalloidsCushing diseaseCushing syndromeCutaneous LeishmaniasisCyanide toxicityCyanosis - Central and PeripheralCyclizineCyclo-oxygenase (COX) enzymesCyclophosphamideCycloserineCys leukotriene receptor antagonistsCystic FibrosisCystinosisCystinuriaCytokinesCytomegalovirus infectionsD DimerDNA and RNA short notesDNA replicationDabigatranDalteparinDandy Walker syndromeDantroleneDapagliflozinDarier's DiseaseDarunavirDeQuervain's thyroiditisDeath Certificates (UK)Deep brain stimulationDeep vein thrombosis (DVT)Dehydration PhysiologyDelayed Puberty CriteriaDemeclocyclineDementia with Lewy bodiesDementiasDemyelinating DiseasesDengue FeverDenosumab (Prolia)Dental AnatomyDentatorubral pallidoluysian atrophyDepressionDermatitis HerpetiformisDermatology termsDermatomesDermatomyositisDermoid cystsDesferrioxamineDesmopressin (DDAVP)Desogestrel (Progestogen Only Pill)Developmental Dislocation (Dysplasia) of the HipDevelopmental MilestonesDexamethasoneDiGeorge syndrome (thymic aplasia)Diabetes Insipidus (Cranial and Nephrogenic)Diabetes Mellitus Type 1Diabetes Mellitus Type 1 and DKA (children)Diabetes Mellitus Type 2Diabetes Mellitus in pregnancyDiabetes on the wardDiabetic Autonomic Neuropathy (DAN)Diabetic Ketoacidosis (DKA) AdultsDiabetic Ketoacidosis (DKA) with SGLT2 InhibitorsDiabetic NephropathyDiabetic RetinopathyDiabetic amyotrophyDiabetic footDiamond-Blackfan anaemiaDiamorphineDiaphragmatic disordersDiarrhoeaDiazepamDidanosine (ddI)DiethylstilbestrolDifferentials causes of Foot DropDifferentials of ABCDifferentials of Generalised lymphadenopathyDifferentials of Painful thighDifferentials of XXXDiffuse Oesophageal spasmDiffuse large B-cell lymphomaDiffusion CapacityDigoxinDigoxin ToxicityDihydrocodeineDilated cardiomyopathyDiltiazemDiphtheriaDipyridamoleDischarges against adviceDiscoid lupus erythematosus (DLE)Disease templateDiseases with associated cancersDislocation Sternoclaivcular jointDisopyramideDisseminated Intravascular Coagulation (DIC)Distributive ShockDisulfiram (Antabuse)DobutamineDog BitesDog Bites HandDominant R wave in V1DomperidoneDonepezil (Aricept)DonovanosisDopamine HydrochlorideDopamine agonistsDown's syndrome (Trisomy 21)DoxapramDoxazosin (Cardura)DoxepinDoxorubicin (Adriamycin)DoxycyclineDrivingDrowningDrug Induced Parkinson diseaseDrug Reaction Eosinophilia Systemic Symptoms DRESSDrug TemplateDrug Toxicity - clinical assessmentDrug Toxicity with Specific AntidotesDrug induced Lupus ErythematosusDrug induced liver diseaseDrugsDrugs ListDrugs to Avoid in Acute Renal failureDrugs to avoid ElderlyDrugs to avoid in Liver failureDry and Wet GangreneDual X-ray absorptiometry (DEXA)Duchenne muscular dystrophyDulaglutide GLP-1 agonistDuloxetineDuodenal Atresia (Children)Dupuytrens contractureDysenteryDysphagiaECG - Acute Coronary SyndromeECG - Acute ST Elevation Myocardial InfarctionECG - Atrial fibrillationECG - Atrial flutterECG - BasicsECG - Broad complex tachycardia (possible VT)ECG - Brugada syndromeECG - Causes of a Dominant R wave in V1ECG - Early Repolarisation vs STEMIECG - First degree AV BlockECG - Heart BlockECG - HyperkalaemiaECG - InterpretationECG - Ischaemic Heart DiseaseECG - Left Axis DeviationECG - Left Bundle Branch Block LBBBECG - Left Ventricular HypertrophyECG - Low Voltage ComplexesECG - Narrow complex tachycardiaECG - Normal appearanceECG - Pathological Q wavesECG - QT intervalECG - Right Axis DeviationECG - Right Bundle Branch Block RBBBECG - ST-T T waves changesECG - Supraventricular tachycardia ECG - The QRS complexECG - Tutorial from Queens UniversityECG - Ventricular fibrillationECG - Ventricular tachycardiaECG - Wolff Parkinson White syndrome (WPW)ECG - short PR intervalECG - sinus pauseECG - tall R wave V1ENT Exam - Assessing hearingENT infectionsEbola Virus DiseaseEbstein anomalyEchinocytesEchocardiogramEcstasy toxicityEctopia lentis (subluxation of the lens)Ectopic PregnancyEctropionEculizumabEdoxaban (Lixiana)Edward syndrome (trisomy 18 syndrome)Efavirenz (Sustiva) EFVEhlers-Danlos syndromesEhrlichiosisEikenella corrodensEisenmenger's syndrome (Children)Elbow fractures and InjuriesElectrical injuryEloquent brainEmergency DrugsEmphysemaEmpty sella syndromeEmtricitabine (Emtriva) FTCEnalaprilEnd of Life Care PrescribingEndocarditis and StrokeEndocrinology Lab valuesEndometrial (Uterine) CancerEndometriosisEndoscopic Retrograde Cholangiopancreatography XEndothelinsEnfuvirtideEnoxaparin Sodium (Clexane-Lovenox)EnoximoneEntacaponeEnterococciEnteropathic SpondyloarthritisEnzyme inducers and inhibitorsEosinophilic granulomatosis (Churg Strauss)EpendymomaEpidural HaematomaEpidural abscessEpilepsy - General ManagementEpilepsy - Idiopathic Generalised EpilepsyEpilepsy - Mesial temporal lobe epilepsyEpilepsy - Post TraumaticEpilepsy in PregnancyEpiscleritisEpistaxisEplerenoneEponymous brainstem strokesEpstein-Barr Virus infectionEquivalent doses of OpiatesErb PalsyErgocalciferol (Calciferol)Erlotinib (Tarceva)Erysipelothrix rhusiopathiaeErythema MultiformeErythema NodosumErythrocyte Sedimentation rate (ESR)ErythrocytesErythrodermic PsoriasisErythromycinEscherichia coliEscitalopramEsomeprazoleEssential Thrombocythaemia (ET)Essential TremorEtanerceptEthambutolEthanolEthanol toxicityEthylene glycol toxicityEtomidateEtravirine (intelence) ETREwing sarcomaExenatide (Byetta) GLP1 agonistExercise stress testExploding head syndromeExtradural haematomaExtrapyramidal symptomsExtrinsic Allergic alveolitis (Hypersensitivity)Eye infectionsEzetimibeFabry diseaseFacial NerveFacioscapulohumeral muscular dystrophyFactor V Leiden DeficiencyFaecal CalprotectinFahr syndromeFailure to thrive or Faltering growthFamilial Adenomatous polyposis (FAP)Familial AmyloidosisFamilial HypercholesterolaemiaFamilial Mediterranean Fever (FMF)Familial hypocalciuric hypercalcaemia (FHH)Family Tree (Pedigree)FamotidineFanconi AnaemiaFanconi SyndromeFat embolismFatigue - CausesFatty acidsFebrile seizuresFelodipine (Dihydropyridine)Femoral HerniaFemoral triangleFemur fractures and InuriesFentanyl - FentanilFerritinFerrous Fumarate - Gluconate - SulphateFetal Alcohol SyndromeFetal circulationFever - Pyrexia of unknown origin (FUO PUO)Fever in a travellerFibratesFibrinogenFibromuscular dysplasiaFibromyalgiaFidaxomicinFinasteride (5 alpha-reductase inhibitor)First SeizureFitz-Hugh Curtis SyndromeFlail ChestFlecainide AcetateFlexor sheath infection (flexor tenosynovitis)FlucloxacillinFluconazoleFlucytosineFludrocortisoneFluid balances statusFlumazenil (Annexate - Romazicon)FluoxetineFocal Segmental Glomerulosclerosis (FSGS)Foix-Alajouanine syndromeFolate (Folic) acidFolate deficiencyFolinic acid (Leucovorin)FomepizoleFondaparinuxFood borne diseaseFoscarnet SodiumFosfomycinFosphenytoinFoster Kennedy SyndromeFournier's gangreneFracture TemplateFractured ClavicleFractured Neck of FemurFractured Pubic RamusFractured ScapulaFractured Shaft FemurFractured Tibia and FibulaFractures Shaft HumerusFractures in ChildrenFractures of Upper humerusFragile X syndromeFrailtyFraser guidelines and Gillick CompetenceFree RadicalsFriedreich's AtaxiaFrontotemporal dementiaFull or Complete Blood Count (FBC CBC)FungiFurosemide (Frusemide)Fusidic acidFusobacteria - Tropical ulcerFusobacteriumG protein-coupled receptorsGP Emergency Drugs CarriedGabapentinGalactorrhoeaGalantamineGamete intra-fallopian tube transfer (GIFT)Gamma Glutamyl Transferase (GGT)Gamma hydroxy butyrate (GHB) toxicityGanciclovir - ValganciclovirGardner syndromeGardnerella vaginalisGas GangreneGastric (MALT) LymphomaGastric CancerGastric Outlet obstruction (pyloric stenosis)GastrinomaGastro Intestinal Stromal Tumours (GIST)Gastro-Oesophageal Reflux (Adult GORD)Gastro-Oesophgeal Reflux (Paediatrics GORD)GastroenteritisGastroenterology Exam ListsGastroenterology ExaminationGastroenterology HistoryGastroenterology assessment - JaundiceGastrointestinal anatomy and physiologyGastrointestinal perforationGastrostomy (PEG) tubesGaucher's diseaseGene componentsGenetic DiseasesGentamicinGiardiasisGilbert's syndromeGingival (Gum) hyperplasia-hypertrophyGitelman's syndromeGlasgow Blatchford ScoreGlasgow Coma scaleGlatiramer acetate (Copaxone)GlibenclamideGliclazideGlimepirideGlipizideGlobus PallidusGlomerulonephritisGlossitisGlucagonGlucagonomaGlucose 6 phosphate dehydrogenase deficiencyGlucose Tolerance TestGlutamateGlycated HaemoglobinGlyceryl Trinitrate (GTN)Glycogen storage diseasesGlycolysis_Krebs_Electron_Transport_ChainGlycopyrronium BromideGoitreGolfer's ElbowGolimumab (Simponi)Goodpasture's syndrome (Anti GBM disease)Goserelin (Zoladex)Gradenigo's syndromeGrades of RecommendationGram StainGranuloma annulareGranulomatosis with Polyangitis GPA (Wegener)Graves DiseaseGriseofulvinGrowth Hormone DeficiencyGuillain Barre SyndromeGum hypertrophyGuthrie test New Born blood spotGynaecological History TakingGynaecomastiaHAS-BLED scoreHIV and Post-Exposure Prophylaxis (PEP)HIV and Pre-exposure prophylaxisHIV associated nephropathy (HIVAN)HIV disease AssessmentHTLV-1 Associated myelopathyHaematemesisHaematology Examination - SplenomegalyHaematology Lab valuesHaematuria Mild to SevereHaemodialysisHaemoglobinsHaemolysisHaemolytic AnaemiaHaemolytic Uraemic syndromeHaemolytic disease of the newbornHaemophilia AHaemophilia BHaemophilus aegyptiusHaemophilus ducreyiHaemophilus influenzaeHaemophilus parainfluenzaeHaemopoiesisHaemorrhagic TransformationHaemorrhagic strokeHaemorrhoids (Piles)Hairy Cell LeukaemiaHairy LeukoplakiaHallervorden-Spatz disease (PKAN)HaloperidolHamman-Rich syndromeHand foot and mouth diseaseHand fractures and InjuriesHantavirus infectionsHartmann's solution (Ringer's lactate)Hartnup disease*Hashimoto's (Steroid responsive) EncephalopathyHashimoto's thyroiditisHbA1cHead (Brain) InjuryHead and Neck CancersHeadache - Analgesic overuseHeadache - Assessing Acute and SevereHeadache - Basilar MigraineHeadache - ClusterHeadache - Low CSF pressureHeadache - MigraineHeadache - TensionHeadaches - GeneralHearing aidsHeat StrokeHelicobacter pyloriHelvetica Spotted feverHemicraniectomyHenoch-Schonlein purpuraHeparin - GeneralHeparin - Low Molecular Weight HeparinHeparin - Unfractionated HeparinHeparin-induced thrombocytopenia (HIT)Hepatic EncephalopathyHepatitis AHepatitis BHepatitis CHepatitis DHepatitis EHepatocellular CarcinomaHepatorenal syndromesHereditary ElliptocytosisHereditary HaemochromatosisHereditary Haemorrhagic TelangiectasiaHereditary Spastic ParaparesisHereditary SpherocytosisHereditary angio-oedemaHereditary neuropathy with pressure palsiesHereditary non polyposis coli (Lynch syndrome)Herpes GestationisHerpes SimplexHerpes Simplex Encephalitis (HSV)Herpes VirusesHerpes Zoster Ophthalmicus (HZO) ShinglesHerpes simplex keratitis (HSK)Heyde syndromeHiatus herniaHiccups (Singultus)High Dose Dexamethasone Suppression TestHip pain in childrenHirschsprung disease (congenital megacolon)Hirsuitism XXXHistonesHistoplasmosisHodgkin LymphomaHolt-Oram syndromeHolter monitor (tape) 24-72 hHomocystinuriaHookwormHorner's syndromeHospital acquired Pneumonia (NICE 139)Human albumin solution (HAS)Human prion diseasesHumeral fractures and injuriesHunter's syndrome (MPS-2)Huntington ChoreaHurler's syndrome (MPS-1)Hydatid disease (Echinococcus)Hydatidiform moleHydralazineHydrocortisoneHydrogen BondsHydrops fetalisHydroxocobalaminHydroxocobalamin - Cyanocobalamin (B12)HydroxychloroquineHydroxyurea-HydroxycarbamideHyoscine (Buscopan)Hyper IgM syndromeHyperbaric Oxygen therapyHypercalcaemiaHyperglycaemic Hyperosmolar State (HHS)Hyperinsulinaemic-euglycemic therapy (HIET)HyperkalaemiaHyperkalaemic and Hypokalaemic Periodic ParalysisHypermagnesaemiaHypernatraemiaHyperphosphataemia (High phosphate)HyperprolactinaemiaHypersensitivity reactionsHypertensionHypertension in PregnancyHypertriglyceridaemia (HTG)Hypertrophic cardiomyopathy (HCM - HOCM)Hyperventilation SyndromeHyperviscosity syndromeHypocalcaemiaHypoglycaemiaHypogonadism (Female)Hypogonadism (male)HypokalaemiaHypokalaemic Periodic ParalysisHypomagnesaemiaHyponatraemiaHypoparathyroidismHypophosphataemia (Low phosphate)Hypopituitarism (Pituitary Failure)HypospadiasHypothermiaHypothyroidismHypovolaemic or Haemorrhagic ShockIL-12 receptor deficiencyIV ImmunoglobulinIbandronic acid (Bisphosphonate)IbuprofenIcatibantIdiopathic Intracranial hypertensionIdiopathic Parkinson diseaseIdiopathic Pulmonary FibrosisIgA Nephropathy (Berger's disease)Images - Spot diagosesImatinib mesylateImipenem (Primaxin) with CilastinImmune Reconstitution SyndromeImmune(Idiopathic) Thrombocytopenic Purpura (ITP)Immunoglobulin G4-related disease (IgG4-RD)ImpetigoImplantable cardioverter defibrillator (ICD)Impulse control disordersInclusion Body MyositisIncubation periodsIndapamideIndinavir (IND)Infection screening in Septic patientInfections and their Microbial causeInfectious MononucleosisInfective ConjunctivitisInfective EndocarditisInfertilityInfliximabInfluenzaInguinal HerniaInitial Trauma AssessmentInjury Severity Score (ISS)Insomnia - sleep issuesInsulinInsulinomaInterferon BetaIntermittent ClaudicationInternal CapsuleInternuclear OphthalmoplegiaInterpreting HaematinicsInterstitial KeratitisIntestinal obstruction (Children)Intra Aortic Balloon PumpIntraabdominal abscessIntracerebral Haemorrhage (ICH) ScoreIntracranial HypertensionXIntravenous Iron Replacement (Ferrous)Intraventricular haemorrhage (neonates)Intubation and Mechanical VentilationIntussusception (Adults)Intussusception (Children)Iodine deficiency GoitreIpratropium Bromide (Atrovent)IrbesartanIron SaltsIron deficiency AnaemiaIron toxicityIrritable bowel syndromeIschaemic ColitisIschaemic StrokeIschaemic heart diseaseIsoniazidIsoprenalineIsosorbide DinitrateIsosorbide mononitrateIsotretinoin (Accutane)Ispaghula Husk (Fybogel)IvabradineJansen DiseaseJanus kinase 2Jervell and Lange-Nielsen syndromeJob Syndrome (Hyper IgE syndrome)Jugular Venous Pressure (JVP)Junctional TachycardiaJuvenile DermatomyositisJuvenile Idiopathic arthritis (Stills Disease)Juvenile Myoclonic epilepsy (JME)Kallmann's syndromeKaposi sarcoma (KS)Karnofsky performance status scaleKawasaki diseaseKennedy SyndromeKeratoconusKernicterusKetamineKetoconazoleKlebsiella pneumoniaKlinefelter Syndrome (Children)Klumpke palsyKnee fractures and InjuriesKoebner phenomenonKugelberg Welander syndromeKwashiorkorL-Thyroxine (T4)Labetalol (Trandate)Labyrinthitis - Vestibular NeuronitisLactateLactate dehydrogenase (LDH)Lactic acidosisLactobacillus acidophilusLactose IntoleranceLactuloseLady Windermere syndromeLambert-Eaton syndrome (LEMS)Lamivudine (3TC)LamotrigineLangerhans Cell Histiocytosis XLansoprazoleLanthanumLateral Medullary SyndromeLaxativesLe Fort FracturesLead toxicityLeber hereditary optic neuropathy (LHON)LeflunomideLegal definition of BlindnessLegionella pneumophilaLeishmaniasis (Cutaenous and Visceral)Lemierre's syndromeLenalidomide (Revlimid)Length Dependent PolyneuropathyLennox-Gastaut syndromeLenticulostriate branch occlusionLeprosyLeptinLeptospira interrogansLeptospirosis (Weil's Disease) (Notifiable)Leriche syndrome (aortoiliac occlusive disease)Lesch-Nyhan syndrome (Children)LeukaemiaLeukaemias in GeneralLeukoariosisLeukocytoclastic vasculitisLeukotrienesLevetiracetam (Keppra)LevodopaLevomepromazineLevosimendanLi Fraumeni syndromeLichen PlanusLiddle's syndromeLidocaine(Lignocaine)Lightning strikeLimb girdle dystrophyLimbic EncephalitisLinagliptin (Trajenta)LinezolidLinkageLiothyronine Sodium L-Triodothyronine (T3)Lipid emulsion therapy - IntralipidLipid management [NICE 2014]LipoatrophyLipoprotein lipase deficiencyLiraglutide (Victoza)LisinoprilListerial MeningitisListeriosisLithiumLithium toxicityLivedo ReticularisLiver Anatomy PhysiologyLiver BiopsyLiver Function TestsLiver TransplantationLiver abscessLiver disease in PregnancyLocalisation of cortical functionLofepramineLong QT syndrome (LQTS) AcquiredLong QT syndrome (LQTS) CongenitalLong term Oxygen therapy (LTOT)Loop diureticsLooser's zonesLoperamideLopinavirLoratadineLorazepamLosartanLow Dose Dexamethasone Suppression TestLower Gastrointestinal BleedingLugol iodineLumbar puncture and CSF interpretationLumbrosacral radiculopathyLung AbscessLung CancerLung ComplianceLung EmpyemaLung TransplantLupus NephritisLupus VulgarisLyme diseaseLymphocytic HypophysitisLymphogranuloma Venereum (LGV)LyonizationLysosomal storage diseasesMCune Albright syndromeMELASMacrocytic anaemiaMacroglossiaMagnesium PhysiologyMagnesium Sulphate - SulfateMagnetic resonance cholangiopancreatographyMagnetic resonance imagingMajor Histocompatibility complexMalabsorption - small intestineMalaria (non falciparum)Malaria FalciparumMale InfertilityMale Urethral CatheterisationMale erectile dysfunctionMalignant AscitesMalignant Hyperpyrexia (Malignant Hyperthermia)Malignant HypertensionMalignant MelanomaMalignant pleural mesotheliomaMallet FingerMallory-Weiss TearMalnutrition Universal Screening ToolManiaMannitolMantle cell lymphomaMarantic EndocarditisMarasmusMaraviroc (Celsentri)Marfan syndromeMarginal Zone LymphomaMassive HaemoptysisMaturity Onset Diabetes of the Young (MODY)McArdles disease (type V)Measles (notifiable)MebeverineMeckel's diverticulumMeconiumMedian NerveMedical Mnemonics Basic SciencesMedical Mnemonics CardiologyMedical Mnemonics EndocrineMedical Mnemonics Mental HealthMedical Mnemonics MiscellaneousMedical Mnemonics NeurologyMedical ProceduresMedical TeethMedullary Sponge kidneyMedulloblastomaMefenamic acidMefloquine (Larium)Megaloblastic anaemiaMelatoninMelioidosisMemantine HydrochlorideMembranous GlomerulonephritisMenetrier diseaseMeniere diseaseMeningiomaMeningitis in the ImmunocompromisedMenopauseMenstrual cycleMental Capacity Act 2005Mental Health Act 1983Mental State ExaminationMercaptopurineMeropenemMesalazine (Aminosalicylate)Mesangiocapillary GlomerulonephritisMesenteric infarctionMetabolic Syndrome XMetabolic acidosisMetabolic alkalosisMetachromic leucodystrophyMetastatic AdenocarcinomaMetastatic bone diseaseMetforminMethaemoglobinaemiaMethanol ToxicityMethodoneMethods to reduce toxin absorptionMethotrexateMethylcelluloseMethylprednisoloneMetoclopramideMetolazoneMetoprololMetronidazole (Flagyl)Metyrapone (Metopirone)MiconazoleMicroangiopathic Haemolytic anaemiaMicrocytic anaemiaMicroscopic PolyangiitisMicroscopic colitisMicrostomiaMidazolamMiddle East Resp Syndrome (MERS) CoronavirusMidodrineMigraine Disability Assessment (MIDAS)Miller-Fisher syndromeMilwaukee shoulder syndromeMini Mental State Examination (MMSE)Minimal Change Disease GlomerulonephritisMinocyclineMinoxidilMirabegronMirizzi syndromeMirtazapineMiscarriageMisoprostolMitochondrial diseasesMitral Regurgitation (Incompetence)Mitral StenosisMitral Stenosis vs Regurgitation - DominanceMitral Valve prolapseMittleschmerzMixed Connective Tissue Disease (MCTD)Mobility aidsModified Duke Criteria for EndocarditisModified Oxford Handicap Scale (MOHS)Modified Rankin ScoreMolluscum contagiosumMonoclonal gammopathy of undetermined significanceMonocular loss of visionMonocytesMonosodium glutamate (MSG) syndromeMontelukastMontreal Cognitive Assessment (MOCA)Moraxella catarrhalisMorphine SulphateMosquito borne diseasesMotor Neuron Disease (MND-ALS)Moyamoya diseaseMucormycosisMultifocal Atrial TachycardiaMultifocal Motor Neuropathy with Conduction blockMultiple Antithrombotics AnticoagulantsMultiple Endocrine Neoplasia type 1 (MEN1)Multiple Endocrine Neoplasia type II (MEN2)Multiple MyelomaMultiple PregnancyMultiple Sclerosis (MS) DemyelinationMultiple System Atrophy (MSA)Mumps (Notifiable)Muscles of the Abdominal RegionMuscles of the BackMuscles of the Head and NeckMuscles of the Lower LimbMuscles of the Pelvis and PerineumMuscles of the Thoracic RegionMuscles of the Upper limbMyasthenia GravisMycobacterium TuberculosisMycophenolate mofetilMycoplasma pneumoniaeMycoplasmasMycosis Fungoides (Sezary Syndrome)Myelodysplastic syndrome (Myelodysplasia)MyelofibrosisMyelofibrosis vs CMLMyelopathyMyeloproliferative disordersMyobacterium avium Complex InfectionMyocardial perfusionMyoclonusMyotonic dystrophy - Dystropica myotonicaMyxoedema comaN-Acetylcysteine (Parvolex)NEWS Reacting to Low Oxygen SaturationsNICE Guidelines LinksNICE Trauma Guidance Summary 2016NSAID toxicityNaloxone (Narcan) Opiate antagonistNaproxenNarcolepsyNasal polypsNasogastric tube insertionNatalizumab (Tysabri)National Early Warning Score NEWS 2 ScoreNeck PainNeck swellings and lumpsNecrotising Enterocolitis (Infants)Necrotising fasciitisNeedlestick injuryNefopamNeisseria gonorrhoeaeNeisseria meningitidisNelson SyndromeNeomycinNeonatal Abstinence Syndrome NASNeonatal JaundiceNeonatal Lupus ErythematosusNeonatal meningitisNeostigmineNephritic syndromeNephroblastoma (Wilm's tumour)Nephrotic syndromeNephrotoxic drugsNerve conduction studiesNerve fibresNeuroanatomy 101Neuroanatomy imagesNeuroblastomaNeurocysticercosisNeuroferrinopathyNeurofibromatosis Type 1Neurofibromatosis Type 2Neuroleptic Malignant SyndromeNeurological - Relative Afferent pupillary defectNeurological - Vision and Eye movementsNeurological Examination - CognitionNeurological Examination - Cortical FunctionsNeurological Examination - MotorNeurological Examination - SensoryNeurological Examination - Speech&LanguageNeurological ListsNeurological assessment - PtosisNeurological examination - EyesNeurological or ENT Examination - NystagmusNeurology - History takingNeurology Exam - Reflex findingsNeuromyelitis optica*Neuropathic Pain ManagementNeurotransmittersNeutropeniaNeutropenic SepsisNeutrophil Alkaline PhosphataseNeutrophilsNevirapine (Viramune) NEV-NVPNiacin deficiency (Pellagra Vitamin B6)Nicardipine (Cardene)NicorandilNiemann-Pick diseaseNifedipineNimodipine (Nimotop)Nitric OxideNitrofurantoinNitrous oxideNizatidineNocardiaNoise induced hearing lossNon Alcoholic Fatty Liver Disease NAFLDNon Convulsive Status EpilepticusNon Hodgkin LymphomaNon alcoholic steatohepatitis (NASH)Non gonococcal urethritisNon invasive ventilation (NIV)Non steroidal anti inflammatory drugs (NSAIDs)Non sustained Ventricular tachycardiaNoonan syndromeNoradrenalineNormal DistributionNormal Pressure HydrocephalusNormal Saline 0.9%Normocytic anaemiaNortriptylineNosocomial infectionsNotifiable disease and organisms UKNutrition in Infants BreatsfeedingNystatinOSCE - Administer IV InjectionOSCE - Blood cultureOSCE - VenepunctureOSCE - Venous Cannula InsertionObsessive-Compulsive disorderObstetric definitionsObstructive ShockObstructive Sleep ApnoeaOctreotideOculomotor Nerve (IIIrd Cranial Nerve)OedemaOesophageal CarcinomaOesophageal Perforation - RuptureOesophageal Variceal BleedingOesophagogastroduodenoscopyOlanzapineOlfactory Nerve (I)OligodendrogliomaOlmersartanOlsalazine (Aminosalicylate)OmalizumabOmeprazoleOnchocerciasisOncogenic virusesOncological emergenciesOndansetronOne Table TemplateOphthalmology Exam ListsOpiate ToxicityOpiatesOpicaponeOpioid toxicityOptic Neuritis-NeuropathyOptic atrophyOptic tract anatomyOral Aphthous UlcersOral CandidiasisOral LeukoplakiaOrbital vs Preorbital CellulitisOrganism and sensitivitiesOrganophosphate (OP) PoisoningOrphenadrineOrthopaedic infectionsOrthostatic - Postural hypotensionOscillopsiaOseltamivir - TamifluOsteoarthritisOsteogenesis ImperfectaOsteogenic sarcoma (Osteosarcoma)Osteomalacia-Rickets-Vitamin DOsteomyelitisOsteonecrosis of the jawOsteopetrosisOsteoporosisOtitis Externa (Malignant)Otitis MediaOtosclerosisOttawa rules for ankle and foot x-rayOvarian CancerOvarian CystOvaryOxford community stroke project (Bamford)Oxybutynin (Ditropan)Oxycodone (Oxycontin-Oxynorm)Oxygen delivery devicesOxytetracyclinePEDIS Score for Diabetic Foot UlcersPOEMS syndromePabrinexPacemaker DDDPacemaker VVIPacemaker syndromePacemakersPacing - Indications for temporary pacingPaediatric emergenciesPaediatricsPaget's (Bone) diseasePain ManagementPainful Shoulder syndromesPalliatiion - Nausea Dyspnoea Secretions PainPalliation prescribingPalpitationsPamidronate (Bisphosphonate)Pancoast tumour (Cancer)Pancreatic CancerPanton-Valentine leucocidin toxinPantoprazolePapilloedemaParacetamol (Acetaminophen)Paracetamol toxicityParadoxical embolisationParaneoplastic Encephalitis with NMDA antibodiesParaneoplastic Limbic Encephalitis (Dementia)Paraneoplastic cerebellar degenerationParaphimosisParaquat toxicityParkinson Plus syndromesParkinsonismParonychiaParoxetineParoxysmal Nocturnal HaemoglobinuriaParvovirus (Erythrovirus 19) B19 infectionPasteurella multocidaPatau syndrome (trisomy 13)Patent Ductus arteriosus (PDA) (Children)Patent Foramen Ovale (PFO)Pathogen - pattern recognition receptorsPathological bone fracturePegvisomantPelvic fracturesPemphigus VulgarisPenetrating Abdominal TraumaPenetrating Thoracic TraumaPenicillaminePenicillinsPenile CancerPeptic ulcer diseasePercutaenous Coronary Intervention (PCI ACS)PergolidePericardial Effusion_TamponadePerimesencephalic Subarachnoid haemorrhagePerindoprilPerinephric abscessPerioperative AnticoagulationPeripartum cardiomyopathyPeripheral Arterial Disease (PAD)Peripheral Cannula InsertionPeripheral Nerve Palsies*Peripheral neuropathyPeripherally inserted central cathetersPernicious anaemiaPerthes disease (Osteochondritis of the Hip)PethidinePeutz-Jeghers syndromePhaeochromocytomaPhagocytesPharmacokinetic notesPharmacokineticsPharyngeal arch derivativesPhenobarbital sodiumPhenoxymethylpenicillin (Penicillin V)PhentolaminePhenylketonuria (PKU)Phenytoin (Dilantin)Philadelphia chromosomePhimosisPhobic disordersPhocomelia and ThalidomidePhosphorusPhysiology of visionPicolax - CitrafleetPilonidal Abscess (sinus)Pioglitazone (Thiazolidinediones)Pituitary AdenomaPituitary Anatomy and PhysiologyPituitary ApoplexyPityriasis or Tinea versicolor infectionsPityriasis roseaPivmecillinam (a penicillin antibiotic)Placenta praeviaPlacental abruptionPlantar fasciitisPlasmacytomaPlasmapharesisPlasmidsPleural effusionPleural tap (thoracentesis)Pneumococcal meningititisPneumoconiosisPneumocystis jirovecii pneumoniaPneumoniaPneumothoraxPoisons eliminated Haemodialysis - perfusionPoliomyelitisPolyarteritis nodosa (PAN)Polyarticular arthritisPolycystic Ovary syndromePolycythaemia Vera (primary polycythaemia)Polymerase chain reactionPolymorphic light eruptionPolymyalgia RheumaticaPolymyositisPolypharmacy Start CriteriaPolypharmacy Stop CriteriaPolyuriaPontine-Midbrain haemorrhagePorphyria Cutanea Tarda (PCT)Porphyria TestingPortal HypertensionPositron Emission TomographyPost Menopausal BleedingPost Operative ManagementPost Partum ThyroiditisPost Polio SyndromePost SplenectomyPost Streptococcal/Infectious GlomerulonephritisPost Stroke Epilepsy (PSE)Post traumatic stress disorderPost-exposure prophylaxis with ImmunoglobulinsPosterior Reversible Encephalopathy Syndrome (PRESPosterior circulationPostpartum haemorrhagePotassium PhysiologyPralidoximePramipexole (Mirapexin)PrasugrelPravastatinPraxbind - IdarucizumabPraziquantelPrazosinPre-Operative AssessmentPreEclampsia, Eclapsmia and HELLPPrednisolonePrednisonePregabalinPremature LabourPremature MenopausePresbyacusisPrescribing InformationPrescribing in PregnancyPressure soresPrevotella (Bacteroides) melaninogenicaPriapismPrimaquinePrimary (Chronic simple) Open angle GlaucomaPrimary Biliary CirrhosisPrimary CNS LymphomaPrimary HyperparathyroidismPrimary Sclerosing CholangitisPrimary ciliary dyskinesiaPrimary hyperaldosteronism (Conn's syndrome)Primary progressive aphasia (Dementia)ProbenicidProchlorperazine (Stemetil)ProcyclidineProgressive Multifocal Leukoencephalopathy (PML)Progressive Supranuclear Palsy (PSP)ProlactinomaPropafenonePropanthelinePropionibacteriumPropofolPropranololPropylthiouracilProstate cancerProsthetic ValvesProtamine SulfateProtein C DeficiencyProtein S DeficiencyProtein losing enteropathyProtein p53Protein synthesisProteusProthrombin 20210A mutationProthrombin Complex Concentrates (PCC)Prothrombin time and CoagulationProthrombotic disordersProton Pump InhibitorsProximal myopathyPrucalopridePsammoma bodiesPseudohypoparathyroidismPseudomonas infection (Pseudomonas aeruginosa)Psoas AbscessPsoriasisPsoriatic arthritisPsychogenic PolydipsiaPubic Lice (Pediculosis Pubis)Pulmonary Alveolar ProteinosisPulmonary Arteriovenous malformationPulmonary EmbolismPulmonary Eosinophilia and CXR changesPulmonary HypertensionPulmonary Hypertension - PrimaryPulmonary RegurgitationPulmonary StenosisPulmonary hypertension - SecondaryPulse oximetryPutamenPutaminal HaemorrhagePyloric stenosis (Children)Pyoderma gangrenosumPyonephrosisPyrazinamidePyridostigminePyruvate Kinase deficiencyQuetiapineQuinineQuinine toxicityRabiesRadial PulseRadial nerveRadiation exposureRadioactive iodine (I 131)Radiofrequency Catheter AblationRadius and Ulna fractures and InjuriesRaloxifeneRaltegravirRamiprilRamsay Hunt syndromeRanitidineRanolazineRapid sequence intubation (RSI)Rapidly Progressive GlomerulonephritisRasagilineRasburicaseRaynaud's PhenomenonReactive arthritisRectal ProlapseRed cell aplasiaRed eyeRefeeding syndromeReferring to Level 2 or 3 care (ITU ICU HDU)Refractive ErrorsRefsum's diseaseRelapsing polychondritisRemdesvir (Veklury)Renal Artery StenosisRenal Papillary NecrosisRenal Physiology IRenal Stones (Nephrolithiasis)Renal TransplantationRenal Tubular AcidosisRenal Vein ThrombosisRenal cell carcinomaRenal physiologyRenin and Aldosterone Renin ratio (ARR)Renin-angiotensin systemRespiratory (Chest) infections and pneumoniaRespiratory - History TakingRespiratory AcidosisRespiratory AlkalosisRespiratory Anatomy and PhysiologyRespiratory Disease InvestigationsRespiratory Distress Syndrome (Neonates)Respiratory ExaminationRespiratory Examination - Finger ClubbingRespiratory Failure (hypoxia-hypercarbia)Resting membrane potentialRestless legs syndromeRestriction enzymesRestrictive CardiomyopathyResuscitation - Adult Bradycardia AlgorithmResuscitation - Adult Tachycardia AlgorithmResuscitation - Advanced Life SupportResuscitation - Basic Life Support ABCDEResuscitation - Choking AlgorithmResuscitation - Post Resuscitation AlgorithmReteplaseReticulocytesRetinal detachmentRetinitis pigmentosaRetinoblastomaRetinoidsRetroperitoneal fibrosisRett SyndromeReversible cerebral vasoconstriction syndromeReye syndromeRhesus haemolytic diseaseRheumatoid arthritisRheumatology AutoantibodiesRheumatology Lab valuesRhodococcus equiRibavirinRicin ToxicityRickettsia (General Principles)Rickettsia africae (Tick Bite Fever)Rickettsia akariRickettsia conorii (Tick Bite Fever)Rickettsia prowazekiiRickettsia rickettsiiRickettsia tsutsugamushiRickettsia typhiRifampicin (Rifabutin Rifampin)RifaximinRilipivirine (Edurant) RVPRiluzole (Rilutek)Risedronate (Bisphosphonate)RisperidoneRitonavir (Norvir) RTVRituximab (Mabthera)Rivaroxaban (Xarelto)Rivastigmine (Exelon)Rocky Mountain Spotted FeverRocuroniumRotigotineRubella (German Measles) NotifiableSCL70 AntibodySMASH U Intracerebral Haemorrhage ClassificationSOCRATES mnemonicST segment changesSacubitril with ValsartanSalivary Gland DiseaseSalivary glandsSalmonella entericaSalmonella typhiSaquinivir (Invirase) SQVSarcoidosisSaxagliptin (Onglyza)ScabiesScarlet Fever (Scarlatina)SchistosomiasisSchizophreniaSchmidt's syndromeSciaticaSeborrheic DermatitisSecondary Brain TumoursSecondary MessengersSecondary dysmenorrhoeaSecondary hyperparathyroidismSedation and Analgesia on ITUSelective IgA deficiencySelective Serotonin reuptake Inhibitor toxicitySelective serotonin reuptake inhibitors (SSRI)SelegilineSelenium deficiencySennaSeptic Shock and Sepsis 3Septic arthritisSepticaemiaSeronegative SpondyloarthropathiesSerotonin syndromeSerratiaSevelamerSevere combined immunodeficiency disordersSex Linked RecessiveSheehan's syndromeShigella characteristicsShigellosis (Bacillary Dysentery)Shock (General Assessment)Short Synacthen test (SST)Short and Tall stature Growth in ChildrenShoulder dislocationsSick Euthyroid SyndromeSickle Cell DiseaseSideroblastic AnaemiaSigmoid VolvulusSildenafil (Viagra)SilicosisSilver Trauma - Age over 65SimvastatinSinus BradycardiaSinus Node diseaseSinus TachycardiaSitagliptinSitosterolemiaSjogren's syndromeSkin and soft tissue infectionsSkull AnatomySleep physiologySlipped Upper Femoral Epiphysis (SUFE)Small Bowel IschaemiaSmall Bowel ObstructionSmall vessel diseaseSmallpoxSmokingSnake BitesSneddon SyndromeSodium BicarbonateSodium NitroprussideSodium PhysiologySodium PicosulfateSodium Thiopental - Sodium ThiopentoneSodium Valproate (Epilim Depakote)Sodium Zirconium Cyclosilicate (Lokelma)Soft tissue injuries (sprains, strains)SolifenacinSolitary Pulmonary NoduleSotalol HydrochlorideSpetzler-Martin Grading of AVMSpina BifidaSpinal Cord AnatomySpinal Cord Arteriovenous MalformationsSpinal Cord CompressionSpinal Cord HaematomaSpinal Cord InfarctionSpinal StenosisSpirometrySpironolactoneSpleenSplenic RuptureSpondylolisthesisSpontaneous Bacterial PeritonitisSpontaneous intracranial hypotensionSquamous Cell CarcinomaSt John's WortStaphylococcal InfectionsStaphylococcus aureusStaphylococcus epidermidisStaphylococcus saprophyticusStatinStatus Epilepticus (Epilepsy)Stavudine (Zerit) d4TStevens-Johnson SyndromeStiff Person SyndromeStrabismus (Lazy Eye)Streptobacillus moniliformisStreptococci - anaerobesStreptococcusStreptococcus agalactiaeStreptococcus milleriStreptococcus pneumoniae (Pneumococcus)Streptococcus pyogenesStreptococcus viridansStreptokinaseStreptomycinStridorStroke - Arterial Occlusion and clinical correlateStroke - Epidemiology and risk factorsStroke - General ManagementStroke - ImagingStroke ASPECTS scoringStroke CollateralsStroke Risk FactorsStroke ThrombolysisStrongyloides stercoralis (threadworm)StrontiumSubacute Sclerosing PanencephalitisSubacute ThyroiditisSubarachnoid HaemorrhageSubclavian Steal SyndromeSubclavian vein thrombosisSubdural haematomaSucralfateSudden Cardiac Death (SCD)Sudden Infant Death Syndrome (SIDS)Sudden sensorineural hearing loss (SNHL)SuicideSulfasalazine - SulphasalazineSulphonamide (Sulphamethoxazole)SumatriptanSuperior Mesenteric Artery (SMA) SyndromeSuperior Sagittal Sinus ThrombosisSuperior vena caval obstruction syndromeSupracondylar Femur FracturesSupracondylar Humerus FracturesSupraspinatus tendonitisSupraventricular TachycardiaSurgical CricothyroidotomySurgical prophylaxisSurgical site infectionSusac syndromeSuxamethoniumSydenham's choreaSynchronised DC CardioversionSyncopeSyndrome X (Cardiology)Syndrome of Inappropriate ADH (SIADH) secretionSyndromes with Severe Cognitive IssuesSyphilisSyringobulbiaSyringomyeliaSystemic AmyloidosisSystemic Lupus Erythematosus (SLE)Systemic MastocytosisSystemic SclerosisT cellsTIMI scoreTMN Staging tumoursTNF receptor-associated periodic syndromeTORCH infectionsTURP Hyponatraemia syndromeTabes dorsalisTacrolimusTafamidisTakayasu arteritis (pulseless disease)Takotsubo CardiomyopathyTamoxifenTamsulosin (Flomax)Tanner Stages of Pubertal DevelopmentTardive DyskinesiasTay-Sachs diseaseTazocin (Tazobactam - Piperacillin)TeicoplaninTelomeresTemazepamTemozolomide (Temodal)Template XTemplate two columns listTemporal (Giant Cell GCA) ArteritisTenecteplaseTennis ElbowTensilon testTension PneumothoraxTerbutalineTeriparatideTerlipressinTertiary hyperparathyroidismTesticular CancerTesticular torsionTestingTetrabenazineTetracosactide (Synacthen)TetracyclinesTetralogy of Fallot (Children)Thalamic HaemorrhageThalamic Pain SyndromeThalamic Stroke SyndromeThalidomideTheophyllineTheophylline toxicityThiamineThird Degree (complete) Heart BlockThoracic TraumaThoracic anatomyThoracic outlet syndromeThrombocytosisThrombolysisThrombophilia testingThrombotic Thrombocytopenic purpura (TTP)Thyroglossal Cyst (Children)Thyroid CancerThyroid Function Tests and antbodiesThyroid GlandThyroid Storm - Thyrotoxic crisisThyroid Surgery (Thyroidectomy)Thyroid noduleThyrotoxicosis and HyperthyroidismTiagabineTibia and Fibula fractures and InjuriesTicagrelorTick ParalysisTimololTinea capitisTinidazoleTinzaparin (Innohep)Tiotropium (Spiriva)Titre - TiterTocilizumabTolbutamideTolcaponeTolosa Hunt SyndromeTolterodineTolvaptanTongue tie - ankyloglossia (Children)Topiramate (Topamax)Torsades de pointes (Polymorphic VT)Total Anomalous Pulmonary Venous DrainageToxic Epidermal Necrolysis (TEN)Toxic MegacolonToxic Shock SyndromeToxoplasmosisTramadolTranexamic AcidTranscatheter aortic valve implantation (TAVI)Transfer factor (TLCO)Transfusion ten commandmentsTransient Global Amnesia (TGA)Transient Ischaemic Attack (TIA)Transient Monocular Blindness (TMB)Transoesophageal Echocardiography (TOE-TEE)Transplant and organ rejectionTransposition of the great arteries (Children)Transverse myelitisTrastuzumab (Herceptin)Traumatic Spinal InjuryTravellers DiarrhoeaTrazodoneTreponemaTriangles of the neckTrichinellosisTricuspid Atresia (Children)Tricuspid RegurgitationTricuspid StenosisTricyclic Antidepressant ToxicityTricyclic antidepressantsTrigeminal NerveTrigeminal neuralgiaTrihexyphenidyl (benzhexol)TrimethoprimTrinucleotide (triplet) repeatsTrochlear NerveTropheryma whipplei (Whipple disease)Tropical SprueTruncus Arteriosus (Children)TuberculosisTuberculous MeningitisTuberous sclerosisTularaemiaTumour Lysis SyndromeTumour markersTurcot's syndrome (Brain tumor polyposis syndrome)Turner's syndrome (Children)Two list Table templateTyphoid - Paratyphoid fever (Enteric Fever)Tyrosine Kinase receptorsUS vs UK Drug namesUbiquitinUlcerative ColitisUlnar nerveUltrasound - Echo basicsUndifferentiated Inflammatory Arthritis (Children)Unexplained symptomsUpper Gastrointestinal Bleed (GI Bleed)Upper-Lower Motor Neurone signsUrea and ElectrolytesUrethral syndomeUrinary CatheterisationUrinary Incontinence (Stress and Urge)Urinary Tract Infection (UTI Children)Urinary Tract InfectionsUrinary Tract ObstructionUrinary UTI Antibiotic guidanceUrine AnalysisUrothelial tumoursUrticariaUterusVIPomasVTE DVT PE in PregnancyVaginal CarcinomaValaciclovirValsartanVancomycinVariable rate intravenous insulin infusion VRIIIVariant (Prinzmetal) AnginaVaricella-Zoster (Chickenpox Shingles) InfectionVariegate PorphyriaVascular DementiaVasculitis - General Issues and ClassificationVasopressin (AVP) Antidiuretic hormoneVasovagal syncopeVaughan-Williams ClassificationVecuroniumVedolizumab (Entyvio)VenlafaxineVenous Insufficiency and Leg UlcersVenous access Venflons and Central linesVentilator associated pneumonia (VAP)Ventricular FibrillationVentricular Septal defect (VSD) (Children)Ventricular TachycardiaVentricular ectopic beatsVerapamilVertebral artery dissectionVertigoVesicoureteric reflux (VUR) (Children)Vibrio parahaemolyticusVibrio vulnificusVibrio vulnificus Vigabatrin (Sabril)VinblastineVincristineViral MeningitisViral associated cancersVirusesVisual acuityVitamin A deficiency (Children)Vitamin B1 Thiamine deficiencyVitamin B12 deficiencyVitamin B12 excessVitamin C deficiency (Scurvy)Vitamin D (1,25 OH2)Vitamin D (25 OH D)Vitamin D deficiencyVitamin D resistant rickets (Children)Vitamin K (Phytomenadione)Vitamin K deficiencyVitiligoVoltarol (Diclofenac)Von Gierke Disease (Children)Von Hippel LindauVon Willebrand DiseaseWaardenburg's syndrome (Children)Wagner Classification Diabetic foot ulcersWaldenstrom Macroglobulinaemia (WM)Wallerian DegenerationWarfarinWarfarin and BleedingWater PhysiologyWatershed InfarctsWerdnig Hoffman Disease (Children)Wernicke Korsakoff SyndromeWhite Blood Cells - LeukocytesWilliams Syndrome (Children)Wilson diseaseWiskott-Aldrich syndrome (Children)Wolff-Parkinson White syndrome (WPW)Wolfram syndrome (DIDMOAD)Wound healingX linked Agammaglobulinaemia (Bruton)X linked Hypophosphataemic ricketsX-linked IchthyosisX-linked lymphoproliferative disease (Children)Xeroderma pigmentosumYellow FeverYellow Nail SyndromeYersinia enterocoliticaYersinia pestis - Bubonic PlagueYersinia pseudotuberculosisZZAAAZZ_Abnormal charZabramski Classification of CavernomasZidovudine (Retrovir) AZT - ZDVZieve's syndromeZika virusZinc deficiencyZoledronic acidZollinger Ellison syndromeZolpidemZopicloneeGFR

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Brain MRI


MRI Basics
  • Unlike CT, which requires ionising radiation, MRI is based on the interaction between radio waves and hydrogen nuclei in the body in the presence of a strong magnetic field. There is no ionising radiation and no known safety issues. MRI produces higher quality images than CT. In CT scans must be in the plane of the gantry, that is, axial or semi-coronal. In MRI, one is able to acquire images directly in any plane, that is, the usual axial, sagittal, coronal, or any other.
  • Both modalities focus on the properties of a volume element or "voxel" of tissue. This is represented in 2-D form or picture elements or "pixels". The pixel intensity in CT reflects the electron density but in MRI it reflects the density of hydrogen, generally as water (Hâ‚‚0) or fat. To be more exact, MR signal intensity reflects the density of mobile hydrogen nuclei modified by the chemical environment, that is, by the magnetic relaxation times, T1 and T2, and by motion.
  • A hydrogen nucleus is a single proton. It has a positive charge and spins and so generates a small magnetic field (a "magnetic moment") which are usually randomly distributed. These magnetic moments align when placed in a larger magnetic field. With MRI the magnetic field across the body-sized sample is intentionally made non-uniform by superimposing additional magnetic field gradients that can be turned on and off rapidly. Activation of these additional magnetic fields results in a net gradient in the strength of the magnetic field across the body which is necessary for spatial localisation and imaging. The essential components of an MR imaging system include a large magnet which generates a uniform magnetic field, smaller electromagnetic coils to generate magnetic field gradients for imaging and a radio transmitter and receiver and its associated transmitting and receiving antennae or coils. In addition to these fundamental components, a computer is necessary to coordinate signal generation and acquisition and image formation and display.
  • When the body lies within a strong magnetic field, it becomes temporarily magnetised. This state is achieved when the hydrogen nuclei in the body align with the magnetic field. When magnetised, the body responds to exposure to radio waves at a particular frequency by sending back a radio wave signal called a "spin echo". This phenomenon (NMR) only occurs at one frequency (the "Larmor frequency") corresponding to the specific strength of the magnetic field. The spin-echo signal is composed of multiple frequencies, reflecting different positions along the magnetic field gradient.
  • When the signal is broken into its component frequencies (by a technique called a "Fourier Transform"), the magnitude of the signal at each frequency is proportional to the hydrogen density at that location, thus allowing an image to be constructed. Thus, spatial information in MRI is contained in the frequency of the signal, unlike X-ray-based imaging modalities such as CT.
Sometimes MRI is not possible
  • Brain MRI usually involves lying within a very tight space for between 10 and 30 minutes. Access to the patient is difficult. It is incredibly noisy and communication with radiographers is difficult. One has to be realistic and consider the shortest protocol that will get the important clinical information needed.
  • Some do not tolerate it at all. It is a common paradox and frustration that those in whom it would be of most value can't have one due to one reason or other. There are some open scanners available for those who are claustrophobic but access is often difficult.
Reasons why MRI not possible
  • MRI scanner unavailable, Swan-Ganz catheter
  • Brain aneurysm clips - check with manufacturer, Deep brain stimulator
  • Ocular or other metallic foreign bodies (skull X-ray can help to exclude)
  • Unable to monitor safely in MRI environment - patient too ill
  • Extreme claustrophobia
  • Pacemaker/AICD or recent surgery and clips or metallic foreign bodies.
  • Insulin pumps, neurostimulators, cochlear implants, etc. may be de-programmed
  • Patient unable to lie flat - musculoskeletal or cardiorespiratory reasons
  • Patient kyphosis or obesity
  • Bullets or gunshot pellets near great vessels or vital organs such as lungs, heart or brain
  • Relative C/I in early pregnancy- data lacking
  • Cognitive impairment - sometimes sedation considered if agitated
Examples
T2 FLAIRT2
DWIADC
SWIT1 Sagittal

Metal outside the brain and eye is NOT an absolute contraindication: Magnetic deflection is minimal compared to normal physiologic forces. Cardiac valves), inferior vena cava filters, biliary and vascular stents, IUD's and metallic prostheses are safe unless there is doubt as to positional stability. MRI Policies - Safety and Contraindications . Information is changing all the time. Another useful site is MRI safety.com

MRI with Gadolinium

This is the MRI equivalent of CT with contrast and uses Gadolinium which shortens T1 relaxation times. It is useful when there is suspicion of neoplastic, inflammatory lesions or abscesses. Also useful for detecting meningeal disease. It is not often used in acute stroke unless the diagnosis is in doubt.

MR Angiography
Scan Sequences

Relaxation times
  • T1 relaxation time: Time taken for 63% of longitudinal magnetisation to recover in a tissue. T1 is short in fat and long in water and proteins. Contrast causes T1 shortening.
  • T2 relaxation time: Time taken for 63% of transverse magnetisation to be lost in a tissue. Liquids have long T2 and large molecules a short T2.
  • T2* based on T2 decay and dephasing due to inhomogeneities in the magnetic field. Relevant in Gradient echo imaging.
  • Weighting T1 and T2 weighting can increase tissue contrast
T1 weighted
  • Scanning parameters are set (short TR/short TE)
  • Dark: CSF and anything with increased water (oedema, tumour , infection, infarction, haemorrhage or flow void or calcification).
  • Bright: Fat, subacute haemorrhage, melanin, protein-rich fluid, slow-flowing blood, gadolinium, laminar necrosis of an infarct. White matter is brighter than grey. Myelin is light grey. Grey matter is grey. T1 is better for showing anatomy. An acute stroke will be hypointense.
T2 Weighted
  • Dark: Calcification, Blood products, protein-rich fluid, flow void.
  • Bright: Anything with increased water e.g. CSF, Oedema, tumour , Infarct, inflammation, infection, subdural collection, methaemoglobin in subacute bleed. CSF is white and brain tissue is darker and more intermediate. Fat is dark. Myelin is dark grey. Grey matter is brighter than white matter. Good for identifying pathology. T2 is bright due to water or any oedema in pathology. For example, a fresh infarct with oedema will show up bright or hyperintense after a few days becoming most obvious after a few months. T2 weighted hyperintensities may be seen within 6 hours and are present in 90% by 24 hours.
T2* "star"
  • T2* can be recorded using GRE sequences with a low flip angle, long TE, and long TR
  • Mostly used to detect iron in its various forms. Haemorrhages cause an influx of haemoglobin and haemosiderin into the lesion.
  • The iron in haemoglobin and haemosiderin is paramagnetic and thus causes a susceptibility difference in the damaged region, which shows up as dark regions in T2* scans.
  • Blood looks black and Haemosiderosis can also be detected by T2* scans for the same reason.
  • Calcification shows up bright in a T2* MRI due to its higher diamagnetism than the surrounding tissue.
FLAIR
  • Fluid attenuated inverse recovery.
  • FLAIR scans are T2 scans with the free water signal nulled.
  • CSF is now dark. Useful to see oedema and periventricular lesions which appear bright.
  • An acute ischaemic stroke will be bright
Gradient echo (GRE)
  • Excellent at identifying areas of blood and haemosiderin deposition such as in macrophages around an old bleed.
  • Also useful in identifying microbleeds. Sensitivity for blood approaches CT within first 24 hours of a bleed.
  • After several days GRE is the more sensitive modality.
Diffusion Weighted Imaging
  • Identifies areas where Brownian motion is restricted due to cytotoxic cell death. Useful for identifying early Ischaemic stroke.
  • This is explained by the loss of ATP causes a loss of ion exchange pumps.
  • Water from the extracellular space enters into the intracellular compartment (cytotoxic oedema) and produces a typical bright spot on DWI.
  • These changes are seen even within 30 minutes. A new stroke is bright but an old stroke will have low signal intensity on DWI.
  • The DWI is initially bright white and then gradually fades after 10-15 days when the lesion will be best seen on T2 and FLAIR.
  • The ADC often shows the inverse and is black.
  • The signal intensity of acute stroke on DW images increases during the 1st week after symptom onset and decreases thereafter.
  • The ADC map shows similar findings.
Restricted diffusion: Bright DWI and Dark ADC
  • Infarction
  • Abscess/Cerebritis
  • Lymphoma
  • Creutzfeldt-Jakob disease
Left MCA infarctDWI of an Anterior cerebral artery infarct
Apparent Diffusion Coefficient: (ADC map)

Used with DWI. Ischaemic lesions appear dark. If bright this may suggest the DWI increased signal changes are due to T2 shine through and old i.e. false positive.

Gadolinium Enhancement

Identifies pathology in which there is the breakdown of the blood-brain barrier. Also useful in producing an angiogram. Tumours or other lesions may show ring-like enhancement. T1 with Gadolinium will show increased signal with a pituitary tumour , acoustic neuroma or meningioma.

Susceptibility weighted imaging (SWI)

SWI is an MRI sequence sensitive to paramagnetic compounds which distort the local magnetic field. It can detect blood, iron and calcium etc. and so is useful to detect haemorrhage or blood. Images generate a unique contrast, different from that of spin density, T1, T2, and T2*. It is very sensitive over other sequences. It is not possible to differentiate calcium from the blood. A filtered phase can allow us to distinguish between the two as diamagnetic and paramagnetic compounds will affect phase differently (i.e. veins/haemorrhage and calcification will appear of opposite signal intensity). SWI is very useful in detecting cerebral microbleeds in ageing and occult low-flow vascular malformations, in characterising brain tumour and degenerative diseases of the brain, and in recognizing calcifications in various pathological conditions. The phase images are especially useful in differentiating between paramagnetic susceptibility effects of blood and the diamagnetic effects of calcium. SWI can also be used to evaluate changes in iron content in different neurodegenerative disorders. Reference

  • Comparing T2*and SWI. Clearly, the right-handed image shows more detail

    MRI Imaging
    Acute Ischaemic Stroke
    • T2 Weighted Imaging and FLAIR show increased signal 'bright' which peaks at 7 days and may persist for a month.
    • Diffusion weighted imaging is the most sensitive sequence for acute ischaemia as it shows the diffusion restriction (reduced Brownian motion) of extracellular water due to imbalance caused by cytotoxic oedema within minutes. It can remain bright for up to 3 weeks. Some of the bright areas may be viable. Vasogenic oedema can also give a bright appearance. Chronic Infarction is not bright on DWI.
    • ADC map is initially 'dark' low signal with cytotoxic oedema (acute ischaemic stroke) and then increases in signal later on. Vasogenic oedema increases water diffusion and gives a bright appearance on the ADC map and this is called 'T2 shine through. With time the DWI shows decreased signal intensity and the ADC shows increased ADC values.
    • Gradient echo or T2 star It may also be useful in the very early detection of acute thrombosis and occlusion involving the middle cerebral (MCA) or internal carotid artery (ICA). This may show as a hypointense (dark) signal within the MCA or ICA, often in a curvilinear shape. Note that the diameter of the hypointense signal is larger than that of the contralateral unaffected vessel. This finding is called the susceptibility sign, and it is analogous to the hyperdense MCA sign described for CT imaging.
    • Perfusion weighted imaging requires fast MRI techniques to quantify the amount of MR contrast agent reaching brain parenchyma after an IV bolus. Allows construction of maps of cerebral perfusion. This can show an ischaemic zone.
    • There has been increased using MR as a guide to salvageable tissue using the difference in the volume of the brain with restricted diffusion in the DWI and that with high signal in the flair. When haemorrhage is suspected the sequence of choice is MRI with Gadolinium
    Cardioembolic stroke
    • Typically large vessel stroke or strokes
    • Multiple lesions : Anterior and posterior circulation and bilateral
    • Strokes of different age
    Lacunar Stroke
    • Typically < 1.5 cm diameter usually subcortical hypodensity
    • Within thalamus, caudate, entire subcortex and brainstem especially pons
    • Occluded small penetrating arteries
    Basilar Artery Occlusion
    • Hyperdense Basilar artery in front of pons
    • Confirm with MRA/CTA/DSA
    Carotid Dissection
    • Axial Use Fat suppression T2 shows cross section of artery with thrombus
    • CTA/DSA or CEMRA shows vessel with obstruction or subtotal obstruction
    • MRI or CT may show downstream infraction from occlusion or thromboembolism
    Cerebral/Vertebral venous sinus thrombosis
    • Generalised parenchymal oedema
    • Cerebral Haemorrhage
    • Cerebral infarction which does not fit to typical arterial territory
    • Thrombus may be seen even on NCCT within occluded sinuses and veins
    • Empty sinus or Delta sign - may be seen on CT images post contrast. The sign consists of a triangular area of enhancement or high attenuation with a relatively low-attenuating centre on multiple contiguous transverse CT images obtained in the region of the superior sagittal sinus
    CADASIL
    • CT may be normal or show mild to advanced periventricular small vessel disease
    • Multiple areas white matter T2-hyperintensity and lacunar infarctions concentrated in the anterior temporal lobes and in the deep white matter of the frontal and parietal lobes. There is relative sparing of the occipital lobes.
    • Anterior temporal pole and external capsule lesions have higher sensitivity and specificity for CADASIL.
    • A DSA is typically normal not identifying any significant large vessel disease.
    Primary angiitis of the CNS
    • The Digital subtraction angiogram or CEMRA shows lumen irregularities in distal cerebral arteries.
    MELAS syndrome
    • CT shows widespread infarct like lesions
    • MR shows multiple cortical and subcortical infarct-like lesions that cross vascular boundaries
    • Lesions are most prominent in the parieto-occipital region and basal ganglia.
    • Lesions have a migrating pattern over time, with appearance, disappearance, and reappearance.
    • Variable degrees of generalised cerebral and cerebellar atrophy may also be seen.
    • Basal ganglia calcifications may also be seen.
    • CTA and MRA are usually normal.
    • DSA in the acute phase may show dilated cortical arteries with prominent capillary blush and no arterial occlusion.
    Posterior reversible encephalopathy syndrome (PRES)
    • Marked cerebral oedema which is often widespread
    • Focused predominately in the cortical and subcortical grey matter of the parietal and occipital regions but may also be seen in frontal and inferior temporal-occipital junction and cerebellum.
    • MRI (DWI) has shown that the areas of abnormality represent vasogenic oedema which follows arterial territories
    • DSA has shown diffuse vasoconstriction as well as focal vasoconstriction, vasodilation, and even a string-of-beads appearance consistent with vasospasm or arteritis.
    • There is reduced brain perfusion in regions of PRES.
    Imaging Patterns in Haemorrhagic Stroke
    Hypertensive haemorrhage
    • Gradient echo or T2 star. This can show up bleeds especially small microbleeds
    • Location of Bleeds in putamen, thalamus, and pons.
    • Microbleeds may also be found in the basal ganglia, thalamus, or pons
    Cerebral Amyloid Angiopathy
    • Gradient echo or T2 star can show up bleeds especially small microbleeds
    • Haemorrhages more likely to occur in the temporal and occipital than the frontal and parietal lobes and sites of previous bleeds. There was a slight bias for the posterior circulation.
    • Cerebellum can also be affected.
    • Microbleeds as small as 2 mm may be found on GRE or T2*. Gradient-echo MRI may also show by iron-containing deposits left by old haemorrhages
    Other relevant imaging Diagnoses

    Non Communicating Hydrocephalus

    Radiology of choice is Midsagittal MRI which reveals the drainage pathway in great detail

    • Normal - Lateral ventricles small and 3rd ventricle barely visible
    • Single lateral ventricle dilated (Univentricular hydrocephalus) = Obstruction of one foramen of munro
    • Both lateral ventricles dilated (Biventricular) = Obstruction of both foramen of munro
    • Dilation of Lateral + 3rd Ventricle (Triventricular) = Obstruction at level of aqueduct
    • Dilation of Lateral + 3rd + 4th = Obstruction at foramen of Magendie and Luschka

    Communicating Hydrocephalus

    • All ventricles are modestly dilated.
    • Prominent Subarachnoid spaces and basal cisterns