Ultrasound_19 Flashcards

Health Care
Terms Definitions
STROKE SYMPTOMES:
SEVERELoss of consciousnessComaDeathSevere mental handicapSevere physical handicapMILDVery fewTYPICALHeadacheConfusion & dizzinessVisual disturbancesSlurred or loss of speechDifficulty in swallowing Hemiplegia (paralysis on 1 side)
CAUSES OF CLAUDICATION
ARTERIAL SPASMATHEROSCLEROSISARTERIOSCLEROSISARTERIAL OCCLUSION * DIFFERENTIAL DIAGNOSIS IS NEUROGENIC OR MUSCULOSKELETAL INJURY
WINDKESSEL EFFECT
Arteries are compliantPressure increase in systoleArtery expandsPressure decrease in diastoleArtery contractsProduces flow in diastole
DYSARTHRIA
DYSARTHRIA- slurring and speech distortion due to lack of muscular control - left or right hemisphere
BERNOULLI EXPLAINS
THE INVERSE RELATIONSHIP BETWEEN PRESSURE AND VELOCITY
PLAQUE
material that is atherosclerotic that builds up on the vessel walls; may restrict flow or send small clots distally
TIA SYMPTOMES
SYMPTOMSBlindness in one eye (amaurosis fugax)Dysphasia or aphasia (speech)Contralateral hemiparesis/monoparesis (paralysis)Behavioral disturbances
BROUIT
ABNORMAL LOW RUMBLING SOUND HEARD USING A STETHOSCOPE OVER THE CAROTID ARTERYCAUSED BY TURBULENT BLOOD FLOW AS IT RUSHES BY AN OBSTRUCTIONMAY INDICATE:STENOTIC AREATORTUOUS VESSEL
BYPASS GRAFT
Provides alternative pathway around stenosisRarely performed for ICA diseaseMay be performed for stenosis inProximal CCASubclavian arteryInnominate artery
CLAUDICATION
A reproducible symptom complex brought on by same level of activityPredictablePatient may complain of muscle tiredness or pain with muscle weakness and cramping
PRESSURE SITES WITH ABI
DORSALIS PEDISEasily compressedHPOSTERIOR TIBIALHarder to compressEasier to locatearder to locate
GANGRENE
NECROSIS (DYING) OF TISSUETWO TYPESWET GANGRENEDRY GANGRENEMAY OCCUR WITH SEVERE CHRONIC ARTERIAL DISEASEMAY OCCUR AS A RESULT OF ACUTE ARTERIAL OBSTRUCTION DUE TO TRAUMA OR INJURY
WHAT CONDITION CAN DECREASE BLOOD VISCOSITY
SEVER ANEMIA
DISTURBED FLOW
LOSS OF LAMINAR PROFILEIRREGULAR FLOW PATTERNFLOW IN FORWARD DIRECTIONFLOW OSCILLATES AND WAVERSCAUSED BY :Change in vessel directionChanged velocities
LEFT CCA IS A BRANCH OF
AORTIC ARCH
STEADY FLOW
FLOW WITH CONSTANT SPEED (VENOUS FLOW)
DYSPHASIA
DYSPHASIA - difficulty in speaking - left hemisphere
TRANSTEMPORAL APPROACH
Cephalad to zygomatic archAnterior and slightly superior to earCan visualize the terminal portion of ICA, anterior cerebral, middle cerebral and posterior cerebral artery
TRANSOCCIPITAL APPROACH
Probe placed between posterior margin of foramen magnum and 1st cervical vertebraBasilar artery can be evaluatedIntracranial portions of vertebral arteries can be evaluatedPatient should be in prone or sitting position
LOWER EXTREMITY FLOW POST EXERCISE
VASODILATIONRESISTANCE DECREASESFLOW IS ANTEGRADE THROUGH CARDIAC CYCLE
TYPES OF CLUDICATIONS
BUTTOCK CLAUDICATION - suggests aortoiliac diseaseTHIGH CLAUDICATION - suggests distal external iliac or common femoral artery diseaseCALF CLAUDICATION - suggests superficial femoral artery or popliteal artery diseaseREST PAIN CLAUDICATION - worse with limb elevation; relieved by dependency
BRUITS AND THRILLS
BRUITE-LOW RUMBLING SOUND HEARD UPON AUSCULATIONTHRILLS-PALPABLE VIBRATION FELT AT THE STENOSIS
SPECTERAL ANALYSIS
- analysis of the frequency shifts present in pulsed wave Doppler signals
EMBOLUS
a solid, liquid, or gas traveling in circulation that may cause vessel occlusion
THE FIRST BRANCH OF ASCENDING AORTA BEFORE BECOMING AORTIC ARCH
CORONARY ARTERY
WHAT CONDITIONS CAN INCREASE THE VISCOSITY OF BLOOD
ELEVATED HEMATOCRIT(ERYTROCYTHEMIA)AND DEHYDRATION
LAMINAR FLOW
LAYERS OF BLOOD CELLS MOVING AGAINST ONE ANOTHER, THE FASTEST MOVING FLOW IS IN THE CENTER AND SLOW MOVING AND STATIONARY FLOW REMAIN AT THE WALL.
COMPLIANT MEANS
ARTERIES ARE CAPABLE OF EXPANSION AND CONTRACTION WITH CHANGES IN PRESSURE
CAROTID DISSECTION
Separation of the intima from the mediaSeparate flow channel within the dissected wallPROXIMAL DISSECTIONDISTAL ICA DISSECTIONCauses:Fibromuscular dysplasiaTrauma to neckCongenital weakness of the mediaChiropractic treatment
TRANSIANT ISCHEMIC ATTACK
A neurologic deficit that reverses within 24 hours (usually in minutes)Ischemic deficit affects anterior circulation (ICA)Cause: temporary blood clot in an arteryRisk of stroke increased after TIA10% in next three monthsIncrease by 17 times in next 5 years
SUBCLAVIAN STEAL SYNDROME
Blood destined for brain through vertebral artery is shunted away, due to high grade stenosis or occlusion of innominate artery or subclavian artery (proximal to take off of vertebral artery)
LIMITATIONS IN INDIRECT TESTING
CANNOT DISTINGUISH BETWEEN STENOSIS AND OCCLUSIONONLY DETECTS STENOSIS OF 60% OR MORE (HEMODYNAMICALLY SIGNIFICANT)CANNOT PRECISELY LOCATE THE OCCLUSIVE DISEASEDIFFICULT TO DIFFERENTIATE COMMON ILIAC FROM CFA STENOSISMAY SHOW FALSELY ELEVATED PRESSURES IN DIABETIC PATIENTS
PLUG FLOW
THE LAYERS OF BLOOD CELLS ARE MOVING WITH THE SAME SPEED. IT IS SEEN AT VESSEL ORIGIN
THE VESSELS THAT CARRY BLOOD TO THE ADVENTITIA LAYER OF ARTERIAL WALLS
VASA VASORUM
POSTERIOR TO ANTERIOR CIRCULATION
AORTA TO SUBCLAVIAN ARTERYTO VERTEBRAL ARTERYTO BASILAR ARTERYTO RIGHT POSTERIOR CEREBRAL ARTERYRIGHT POSTERIOR COMMUNICATING ARTERYTO DISTAL ICATO RIGHT MIDDLE CEREBRAL ARTERY
TRANSORBITAL APPROACH
Probe placed on closed eyelid at inner canthus of eyePower must be reducedOphthalmic artery and carotid siphon can be evaluated
ANATOMY OF PERONEAL ARTERY
THE PERONEAL ARTERY BIFURCATES FROM THE TIBEOPERONEAL TRUNK ALONG WITH THE POSTERIOR TIBIAL ARTERY. THIS ARTERY SUPPLIES STRUCTURES IN THE LATERAL SIDE OF THE CALF AND CALCANEAL (HEEL) REGION OF THE FOOT WITH BLOOD. THE ARTERY RUNS ADJACENT TO THE FIBULA AND TERMINATES AS THE EXTERNAL CALCANEAL ARTERY.
INDIRECT PHYSIOLOGIC TESTING
PURPOSE: To detect arterial disease in the lower extremity arteries that is hemodynamically significantOften used as a screening process to differentiate between true claudicators and those with neuropathyCan assess graft patencyProvides follow up assessment for patients with arterial disease
TECHNIQUE FOR ABI
Patient placed in supine positionA BP of arm taken using brachial pulseRecord systolic pressureA BP of ankle taken using posterior tibial pulse and dorsalis pedis pulseRecord systolic pressure using the highest of twoCalculate ratio by dividing the ankle systolic pressure by the arm systolic pressure
BRANCHES OF OPHTHALMIC ARTERY
SUPRAORBITAL A., FRONTAL A., AND NASAL A.
ANEURYSM
+ A DILATION OF ALL THREE LAYERS OF THE ARTERY. + IT IS VERY RARE FOR AN ANEURYSM TO OCCUR IN THE CAROTID ARTERY. + CAUSES INCLUDE TRAUMA, INFECTION, CONGENITAL WEAKNESS OF THE VESSEL WALL, AND ATHEROSCLEROSIS.
EFFECTS OF STENOSIS ON FLOW CHARACTERISTICS
VELOCITY ACCELERATION DUE TO AREA REDUCTION AT THE STENOSIS WHICH RESULTS IN ENERGY LOSSES DUE TO ACCELERATION. DISTAL TO THE STENOSIS TURBULENCE FLOW OCCURS DUE TO ENLARGED AREA AND INCREASED PRESSURE.(EDDY OR VORTICE CURRENTS)
CLINICAL SIGN FOR SUBCLAVIAN STEAL SYNDROM
BRACHIAL BLOOD PRESSURE DIFFERENCE OF 15-20 MM/HGPULSES DECREASED ON AFFECTED SIDEFLOW RESISTANCE IN SUPPLYING VERTEBRAL MAY INCREASE (feeding high resistance bed)SURGICAL TREATMENT: stent, by-pass graft, endarterectomy
SEVERE CHRONIC ARTERIAL DISEASE SYMPTOMS
Rest pain in feet and toesArterial ulcers Tissue death / gangrene
HYDROSTATIC ENERGY IS DEFINED AS
THE WEIGHT OF THE COLUMN OF BLOOD EXTENDING FROM THE HEART TO THE LEVEL WHERE PRESSURE IS MEASURED.
MICROSCOPIC ANATOMY OF ARTERIAL WALL CONTAINS:
TUNICA INTIMA (INNER LAYER COMPOSED OF ONE LAYER OF ENDOTHELIAL CELLS), TUNICA MEDIA (THE THICKEST LAYER COMPOSED OF SMOOTH MUSCLES AND CONNECTIVE TISSUES)AND TUNICA EXTERNA OR ADVENTITIA (THE OUTERMOST LAYER COMPOSED OF FIBROUS CONNECTIVE TISSUES)
ANATOMY OF TIBEOPERONEAL TRUNK
DISTAL TO THE TAKE OFF OF THE ANTERIOR TIBIAL ARTERY IS A SHORT SEGMENT KNOWN AS THE TIBEOPERONEAL TRUNK. THIS SHORT REGION IS SOMETIMES REFERRED TO AS THE PROXIMAL PORTION OF THE POSTERIOR TIBIAL ARTERY. IT QUICKLY GIVES RISE TO THE PERONEAL ARTERY AND THE POSTERIOR TIBIAL ARTERY.
FLOW SEPARATION OR BOUNDRY LAYER SEPARATION IS
IS THE AREA OF LITTLE MOVEMENT DUE TO BIFURCATION OR TORTUOUS VESSEL. CAN ALSO BE DUE TO INTRA LUMINAL DISEASE.IT IS SEEN AS OPPOSIT COLOR CLOSE TO THE WALL
TRIPHASIC FLOW
AKA: MULTIPHASIC FLOWHSYSTOLE: flow toward feetEARLY DIASTOLE: flow toward heartLATE DIASTOLE: flow toward feetAS THREE PHASES
TURBULENT FLOW
FLOW IS CHAOTICDIFFERENT DIRECTIONSDIFFERENT SPEEDSVORTICES AND EDDIESVARIES IN TIME & WITH LOCATIONASSOCIATED WITH BRUITS AND THRILLS
VASOCONSTRICTION
Arteries and arterioles are constricted at restHigh resistance flow below the renal arteries
PHASES OF PULSATILE FLOW
1.SYSTOLE-FORWARDFLOW WITH ACCELARATION2.LATE SYSTOLE/EARLY DIASTOLE-TEMPORARY FLOW REVERSAL DUE TO PERIPHERAL RESISTANCE3.END DIASTOLE-FLOW IS FORWARD AGAIN.
TOTAL ENERGY CONTAINS:
PRESSURE (POTENTIAL)ENERGY, KINETIC ENERGY, GRAVITATIONAL (HYDROSTATIC) ENERGY.
COLLATERAL CIRCULATION
alternate pathways for blood flow
VERTEBRO-BASILAR INSUFFICIENCY (VBI)SYMPTOMES
Symptoms usually bilateralVertigo (most common)Ataxia ( muscle coordination)Weakness in limbsDrop attacksParesthesiaVisual disturbancesNumbness around lips and mouth
STROKE IN EVOLUTION
Neurologic effects increase progressively with timeWorsening may occur for up to two weeks
MECHANISMS CONTROLLING BLOOD FLOW
CARDIAC OUTPUTWALL RESISTANCECOMPLIANCE OF ARTERIESVASOCONSTRICTIONVASODILATION
CAPILLARIES
Vast network of tiny vesselsExchange of nutrients and gasses No more than 1 mm long8-10 microns in diameter
VASODILATION
Arteries and arterioles dilate with exercise Low resistance flow pattern after exercise
STENOSIS
narrowing of an artery, usually caused by plaque build-up
HEMODYNAMICS
the study of the characteristics of blood flow
POISEUILLE'S EQUATION DEFINES
RELATIONSHIP BETWEEN PRESSURE, FLOW VOLUME AND RESISTANCE. IT HELPS ANSWER QUESTION OF HOW MUCH FLUID MOVES THROUGH A VESSLE.
CIRCLE OF WILLIS
ANTERIOR CEREBRAL ARTERIES, DISTAL ICA, ANTERIOR COMMUNICATING ARTERIES, POSTERIOR COMMUNICATING ARTERIES AND POSTERIOR CEREBRAL ARTERIES
STROKE RISK FACTORS (MORE)
Hyperlipidemia (increased serum cholesterol)Polycythemia Vera (increased RBC s)Use of estrogen (oral contraceptives)Family History or personal history
VERTIBEROBASILAR SYMPTOMES
.; drop attacks, vertigo, syncope, diplopia, or other posterior circulation symptoms
TRANSCRANIAL DOPPLER
DUPLEX IMAGING OF THE INTRACRANIAL CIRCULATION IS REFERRED TO AS A TRANSCRANIAL DOPPLER EXAM (TCD).
TRANSMANDIBULAR APPROACH
Probe placed under the mandiblePetrous portion of ICA can be evaluated
5 P s OF ACUTE ARTERIAL OCCLUSION
PAINPALLORPULSELESSNESSPARALYSISPARESTHESIAS
ANTERIOR CIRCULATION CONTAINS:
COMMON CAROTID A., INTERNAL CAROTID A., EXTERNAL CAROTID A.
REYNOLD'S CRITICAL NUMBER
PREDICTS THE ONSET OF TURBULENT FLOWFACTORS: flow velocity, fluid density, radius of vessel, viscosity of blood
LOW RESISTANCE FLOW
CONTINUOUS STEADY FLOW FEEDING A DILATED VASCULAR BED(VESODILATION),EXAMPLE ARTERIES: ICA, VERTEBRAL, RENAL, CELIAC, SPLENIC, HEPATIC
INTRACRANIAL OF ICA INCLUDES:
OPHTALMIC A.ORIGINATES NEAR CAROTID SIPHON,ANTERIOR AND MIDDLE CEREBRAL A WHICH TERMINATE AT THE CIRCLE OF WILLIS, POSTERIOR COMMUNICATING A.
HEMIPARESIS
HEMIPARESIS - paralysis on one side of body - contralateral hemisphere of brain
4 ACOUSTIC WINDOWS FOR TCD
TRANSTEMPORAL APPROACHTRANSORBITAL APPROACHTRANSOCCIPITAL APPROACHSUBMANDIBULAR APPROACH
MILD CHRONIC ARTERIAL DISEASE SYMPTOMS
No symptomsDecreased pedal pulsesDecrease in ankle blood pressure with exercise
STROKE VOLUME
- amount of blood ejected with each contraction
CAROTID BODY TUMOR
Carotid body is located next to carotid sinus between ECA and ICACarotid body is a small mass of vascular tissueFunctions as chemoreceptorA tumor on the carotid body is very vascularBlood supply is via ECATreatment is surgical ( may require ligation of ICA or ECA
CIRCLE OF WILLIS PATHWAY CIRCULATIONS
2 PATHWAYS OF COLLATERAL FLOWCONTRALATERAL HEMISPHEREPOSTERIOR TO ANTERIOR
MODERATE CHRONIC ARTERIAL DISEASE SYMPTOMS
No symptoms at restIntermittent claudicationSignificant decrease in ankle blood pressure with exercise
THE ANKLE BRACHIAL INDEX(ABI)
AKA: ANKLE ARM INDEXPURPOSE: often used as screening process to differentiate true claudicators from pseudo claudicatorsRESULTS USUALLY COMBINED WITH DOPPLER VELOCITY WAVEFORM ANALYSIS
HIGH RESISTANCE FLOW
FLOW OF A PULSATILE NATURE WHICH CAUSE NO OR LITTLE FLOW IN DIASTOLE DUE TO VESOCONSTRICTION OF THE PERIPHERAL VASCULAR BED. EXAMPLE ARTERIES:ECA, SUBCLAVIAN, AORTA, ILIAC, EXTREMITY ARTERIES AND FASTING SMA
FACTORES AFFECTING RESISTANCE TO FLOW
VISCOSITY, VESSEL LENGTH AND VESSEL RADIUS
CONTRALATERAL HEMESFERE CIRCULATION
AORTA TO LEFT CCATO LEFT ICATO LEFT ANTERIOR CEREBRAL ARTERYTO ANTERIOR COMMUNICATING ARTERYRIGHT ANTERIOR CEREBRAL ARTERYTO RIGHT MID CEREBRAL ARTERY
FIBROMUSCULAR DYSPLASIA (FMD)
Dysplasia of the media with overgrowth of collagenPart of collagen vascular system disorder groupOccurs mainly in womenHas bead like appearance on angiographyReduced blood supply to the brain
ANATOMY OF POSTERIOR TIBIAL ARTERY
THE POSTERIOR TIBIAL ARTERY RUNS SOMEWHAT OBLIQUELY DOWN THE MEDIAL POSTERIOR PART OF THE CALF. IT RUNS POSTERIOR TO THE TIBIA AND TERMINATES POSTERIOR TO THE MEDIAL MALLEOLUS. THE ARTERY THEN TERMINATES AS THE MEDIAL, LATERAL, AND PLANTAR ARTERIES OF THE FOOT.
PERIORBITAL CIRCULATION WHICH CAN BECOME PERIORBITAL COLATERALS
1.SUPRAORBITAL A. WHICH JOINS ECA VIA SUPERFICIAL TEMPORAL A.2.FRONTAL A. WHICH JOINS ECA VIA SUPERFICIAL TEMPORAL A.
CHRONIC ARTERIAL DISEASE WAVEFORM CHANGES
With severe disease the arteries will vasodilate at restResistance will decrease distally and produce a monophasic waveformDelayed systolic rise time
ANATOMY OF ANTERIOR TIBIAL ARTERY
THE ANTERIOR TIBIAL ARTERY IS THE FIRST MAJOR ARTERY ARISING FROM THE DISTAL POPLITEAL ARTERY. THIS ARTERY PASSES SUPERFICIAL TO THE INTEROSSEOUS MEMBRANE AND RUNS DEEP IN THE ANTERIOR PORTION OF THE CALF ALONG THE ANTERIOR SURFACE OF THE INTEROSSEOUS MEMBRANE. THE DISTAL PORTION OF THE ANTERIOR TIBIAL ARTERY COURSES TO THE ANTERIOR ASPECT OF THE TIBIA. IT THEN PASSES IN FRONT OF THE ANKLE AND BECOMES THE DORSALIS PEDIS ARTERY ON THE TOP OF THE FOOT.
WHAT HAPPENDS WITH EACH CARDIAC CONTRACTION
PRESSURE IN THE LEFT VENTRICLE RISES RAPIDLY, LEFT VENTRICLE PRESSURE EXCEEDS THAT IN THE AORTA (PRESSURE GRADIANT), AORTIC VALVE OPENS AND BLOOD IS EJECTED, BP RISES.
PREDISPOSING RISK FACTORS FOR STROKE:
Age (rare to uncommon less than 60 years)Hypertension (high pressure damages arterial walls)Sex (1.5 times more common in males)AtherosclerosisHeart disease (atrial fibrillation, damaged valves, recent MI)Diabetes Mellitus (increased risk of HTN or atherosclerosis)ObesitySmoking (irritates endothelial lining)
ARTERIAL ANATOMY OF THE UPPER LEG
THE CFA ARISES INFERIOR TO THE INGUINAL LIGAMENT. IT THEN DIVIDES INTO THE DEEP FEMORAL ARTERY (PROFUNDA FEMORIS) AND THE SUPERFICIAL FEMORAL ARTERY. THE PROFUNDA ARTERY LIES POSTERIOR AND LATERAL TO THE SFA. IT SUPPLIES BLOOD TO THE THIGH MUSCLES AND HIP JOINT. THE PROFUNDA IS DEEP TO THE SFA AND MAY ACT AS A PATHWAY FOR COLLATERAL CIRCULATION WHEN BLOOD FLOW IN THE SFA IS REDUCED. THE SFA RUNS THE LENGTH OF THE THIGH. IT TERMINATES AFTER IT PASSES THROUGH AN OPENING IN THE TENDON OF THE ADDUCTOR HIATUS (AKA HUNTER’S CANAL). THE PROXIMAL SFA IS SUPERFICIAL, BUT DIVES DEEP AS IT TRAVELS INTO THE DISTAL PORTION OF THE THIGH
DOPPLER FLOW PROXIMAL AND DISTAL TO A SIGNIFICANT STENOSIS(GRATER THAN %50)
DOPPLER FLOW PROXIMAL TO A SIGNIFICANT STENOSIS BECOMES HIGHER RESISTANCE AND DISTAL TO STENOSIS BECOMES LOWER RESISTANCE
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