Tumors and Vascular diseases of the Brain

April 3, 2008

Jennifer Villa Frabizzio, M.D.Abington Memorial HospitalRadiology Group of Abington, PC

Board Certified in Diagnostic Imaging with Added Qualifications in Neuroradiology

Topics for DiscussionNeuroimagingThen and Now

Neuroanatomy Vascular and Nonvascular

Vascular DisordersDiagnosis and Treatment

TumorsPrimary and Metastatic Disease

Neuroimaging- Then

Standard RadiographPneumoencephalographyDirect Cerebral Angiography

PneumoencephalograhyIntroduced in 1919 by American Surgeon Dandy WalkerPrimary method of Neurodiagnosis used late until late 1970s early 1980sLumbar puncture performed in sitting positionPatient placed in somersault chair with head suspended in harnessCSF removed and 10-15 mls of air introducedPatient is tilted upside down and 50-60 mls more air introduced

Pneumonecephalography cont.Air outlined brainstem structures and supra tentorial structures to diagnose masses, tumors and cerebral atrophyVery time consuming, could take from one to two hours to performFollowing the procedure patients invariably developed severe headache and maybe a feverSampling of CSF post procedure showed high protein and white blood cells, which seemed to be a response to the airSymptoms would usually resolve within 48hrs

Direct Cerebral ArteriographyPioneered in 1927 by Dr. Egas MonizNeedle was inserted directly into the common carotid artery in the neck and contrast material injectedRapid series of radiographs were taken of the skull in numerous projectionsCurrently studies are preformed by inserting a catheter into the femoral arteryRemains as gold standard for imaging arterial and venous structures

Neuroimaging-NowComputed Axial TomographyCAT SCAN

Magnetic Resonance ImagingMRI

Computed TomographyFrom Greek tomos (slice) and graphein (to write)Generation of three dimensional images for a series of two dimension Xrays taken around a single axis of rotationComputer generated images produce an axial imageEarly CT scans in early 1970s had single slice, allowing imaging of the brain in four minutesModern state of the art scanners can have up to 200 slices and can image the whole body in 30 secondsIodine base contrast material in injected in an arm vein to optimize visualization of vessels and solid organsUses ionizing radiation to obtain images, and should be used with caution in pregnant or pediatric patients

CT cont.

Advanced techniques CT angiography and venography Contrast rapidly injected into an arm vein and timed to visualize arteries and veinsHas become first line minimally invasive procedure to image the intracerebral vasculature and coronary arteries

CT perfusionRapid imaging of the brain after contrast injection followed by computer post processing can generated area in the brain at risk for stroke

Magnetic Resonance Imaging (MRI)Powerful magnetic field used to align hydrogen atoms in the bodyRadiowaves are activated that alter the alignment of this magnetization, allow for the atoms to relax at different rates according to their chemical compositionThese signals are manipulated to reconstruct images of the bodyGreater soft tissue contrast than CTNo ionizing radiationMust be extremely careful to remove all metal from patientsContraindicated in patients with pacemakers

MRI cont.Advanced techniquesMR Angiographydetection of moving molecules done without the injection of contrast to visualize flowing bloodexcellent to visualize head and neck vessels

Gadolinium based contrast agent is injected into an arm vein, mixed with flowing blood and allows for visualization of vessels especially in the chest and abdomen

MRI cont.Diffusion imagingFor visualization of acute stroke, damaged cells swell and cause restricted diffusionMR spectroscopySeparating the chemical composition of brain lesions into different peaks to determine chemical compositionFunctional MRIUsing changes in blood flow to monitor neural activity

NeuroimagingNonvascular

NeuroimagingVascular

Vascular diseasesStrokeTrauma/Intracranial HemorrhageAneurysmArteriovenous Malformations

StrokeAcute episode leading to a neurologic deficit80% are due to ischemia (either thrombotic or embolic)20% other

Transient ischemic attack (TIA)Focal events that resolve in 24hrs

Stroke cont.Of the 80%, three quarters are due to atherosclerotic disease or occlusion of vessels.Diagnosis can be made by both CT and MRI, as well as the advanced images techniquesMRI is more sensitive, it can age strokes and can detect an acute stroke within thirty minutes.CAT scan can detect a stroke within 6 hrs, and is useful to determine if there is underlying hemorrhage

71 year old white femaleFound by husband in the bathroom on the floor, unable to move left side of her body

Brought by EMS to AMH and had a CAT scan

Cont.Admitted to intensive care CAT scan performed 6 hrs later after worsening of symptoms

Cont.Patient continues to deteriorate, despite supportive measuresCAT scan performed 24 hrs after admission

No improvementCAT scan performed 12 hrs later, 48 hrs after admission

19 year old white male

Found unconscious in dorm room by roommate after drinking all night at a fraternity partyFriends had seen him take some pills, found later to be valium (benzodiazepine-tranquilizer)

Anoxic brain injuryLack of blood flow to the brain affects deep grey matter structures and can cause irreversible damageCan also be seen in near drowning, carbon monoxide poisoning

Intracranial HemorrhageNon TraumaticHypertension (most common)TumorotherTraumaticEpidural and subdural HematomasHemorrhagic contusions

Hemorrhage cont.Hypertensive type most common in small arteries off of the middle cerebral arteryHigh mortality depending on size and location

81 year old black maleFound at breakfast with difficulty speakingBrought to AMH by sonRan out of blood pressure medicine last weekVital signs in ERBlood pressure 210/80CAT scan upon arrival

Cont.ICU Staff was unable to control blood pressure, symptoms worsened

Hemorrhage cont.TraumaticSubdural hematomasCommon in the elderly or in children due to child abuseTearing of bridging veins along the edge of the brainCan grow large and may need neurosurgical evacuation

Hemorrhage cont.Epidural hematoma Mostly due to injury to the middle meningeal artery, superficial vessel that runs along the skull Commonly associated with skull fracturesLarge ones are neurosurgical emergencies

AneurysmsMost common type is the berry or saccular aneurysm Are usually congenital or degenerative Focal outpouching of a arteryOccur in specific locations along the Circle of WillisOnce diagnosed, the risk of rupture is 1.3% per yearA ruptured aneurysm requires urgent diagnosis and treatment, due to a high risk of rebleeding and 50% mortality

Aneurysms cont.Patients present with worst headache of life and can have varying stages of consciousnessCAT scan of the brain show diffuse subarachoid hemorrhage, crab of death

Aneurysms cont.TreatmentConventional-crainiotomy and aneurysm clippingNeurointerventional-intravascular coiling

Arteriovenous Malformations (AVM)Network of arteries connected directly to veins with no intervening brain tissue or capillariesCan hemorrhage because of high flow stateTreatmentEndovascular coilingGlueStereotactic Radiosurgery

58 year old female MVA, crashed car into a tree because she blacked outArrives at AMH with headache, bruising but awakeCAT scan performed

Brain TumorsPrimary brain tumors are 70% of all intracranial neoplasmsThe remaining 30% represent metastases from primary tumors elsewhere in the body, common ones include lung and breast cancerMRI with Gadolinium in the modality of choice for diagnosis

Brain tumors cont.Primary Brain Tumors80% are gliomas, the most aggressive is the Gliomblastoma Multiforme (GBM)20% are all others, which include meningiomas from the brain surface, nerve sheath tumors and lymphomaTreatment is a combination of surgery, radiation and chemotherapy

Thank you.

jvfrabizzio@amh.org.