Neonatal NeurosonographyOverviewwithKeyTerms (WordDocument)
and ComparisonStudies(PowerPointPresentation)
Jackie Dillman
M...
Neonatal neurosonographyisanimportanttool indiagnosisof the highrisk,premature or symptomatic
neonate. Sonographyisadvanta...
Table 2. Lobesof the cereberum: ⁶
Frontal lobe mostanterio-superiorlobe
separatedfromthe parietal lobe bythe central cingu...
Paramedianstructuresare:
Frontal Lobe Frontal horn,
lateral ventricle
Temporal horn,
lateral ventricle
Thalamus Choroidple...
planes. The coronal imagesare obtainedbysweepingstartinganteriorpositiontoposterior position.
The most anteriorimage shoul...
Complicationsof subependymalandintraventricularhemorrhage are intraventricularand
extraventicularobstructive hydrocephalus...
Disordersof Histogenesis ¹⁰
Gray mater heterotopia – clumpsof
gray matter in wrongpartsof the
brain
Schizencephaly - abnor...
Key terms:
Anencephaly–cephalicheadof the neural tube failstoclose prenatally,resultinginmissingmajorityof
scalp,skull,and...
A diagrammaticverticalsection through thebrain showing thelocation of the ventricles and the
direction of flowof cerebrosp...
Intraventricular- structurescontainingcerebrospinal fluidinthe brain.⁴
Microcephaly – conditionof headcircumference twosta...
References:
1. Rumack CM, Drose JA:Neonatal andinfant brain imaging, in RumackCM, WilsonSR, JohnsonJA, Charboneau
JW (eds)...
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  1. 1. Neonatal NeurosonographyOverviewwithKeyTerms (WordDocument) and ComparisonStudies(PowerPointPresentation) Jackie Dillman May 2010
  2. 2. Neonatal neurosonographyisanimportanttool indiagnosisof the highrisk,premature or symptomatic neonate. Sonographyisadvantageousoverothermodalitiesasitdoesnotrequire use of ionizing radiation, doesnotrequire sedation,iseasilyreproducible, isaspeedyevaluation andisportable.Cine loopimagingallowsthe retrieval of individual imagesinanuncooperativepatient andallow additional reviewif individual imagescreate aquestionable finding. ColorandpowerDopplerof cranial bloodflow may separate normal flowfromclot andmay aide inprovinga vascular lesion.² Neurosonographyisanimportanttool indiagnosisof typesof hemorrhage;subependylmal, intraventricular,posteriorfossa, andsubarachnoid. ¹ Table 1. Germinal matrix hemorrhage isgradedas:³ Grade 1 Subependymal hemorrhage Grade 2 Intraventricularextension withouthydrocephalus Grade 3 Intraventricularextension withhydrocephalus Grade 4 Intraparenchymal hemorrhagewithorwithouthydrocephalus Post-traumaticinjuryresultinginsubdural orepidural hematomascanbe diagnosedby neurosonography.Brainmalformationsdue tocongenital infectionssuchasrubella,herpesvirus, cytomegalovirus,toxoplasmosisandacquiredinfection suchasmeningitiscanbe diagnosedby neurosonography. Congenital brainmalformationsincludingneural tube closuredisorders, diverticulum,cleavage,andcellularmigrationdisorderscanbe seensonographically. Destructive lesions of cephalicdisordersare alsodiagnosed suchasporencephaly, schizencephaly, anencephaly,colpocephaly,holoprosencephaly,hydrancephalyandmicrocephaly. Thoroughknowledgeof brainanatomyisessentialtothe neurosonographer. The three major areasof the brainare the cerebrum, the cerebellum(little brain) andthe brainstem. The cerebrumisdividedintotwosides:left andrightcerebral hemispheresbythe longitudinalfissure. The hemispheresare connectedinternallybyacommissural tract of neural axonsknownasthe corpus callosum.
  3. 3. Table 2. Lobesof the cereberum: ⁶ Frontal lobe mostanterio-superiorlobe separatedfromthe parietal lobe bythe central cingulate sulcus separatedfromthe temporal lobe bythe lateral sulcus Parietal lobe mostposterior-superiorlobe separatedfromthe frontal lobe bythe central cingulate sulcus separatedfromthe occipital lobe bythe parieto-occipitalsulcus separatedfromthe temporal lobe bythe lateral sulcus Temporal lobe lateral andinferiortofrontal andparietal separatedfromthe frontal andparietal lobesbythe lateral sulcus Occipital lobe posteriorandinferiortoparietal andtemporal lobes. separatedfromthe parietal lobe bythe parieto-occipital sulcus Table 3. The fontanelsatbirthare : ⁷ Anteriorfontanel unpaired;locatedatmidline betweenthe twoparietalbonesandthe frontal bone.Itis the largestfontanel,normallyclosingbetween18-24 months Posteriorfontanel unpaired;locatedatmidline betweenthe twoparietalbonesandthe occipital bone.Due to small size itnormallyclosesatabout2 monthsafterbirth Anterolateral fontanel (sphenoid)¹ paired;locatedlaterallybetweenfrontal,parietal,temporal andsphenoid bones.Due to small size it normallyclosesatabout3 monthsafterbirth Posterolateral fontanel (mastoid)¹ paired;locatedlaterallybetweenparietal, occipital,temporalbones.The closure of thisfontanel isnormallycomplete at12 months Fontanelsprovidewindowsbetween bonesof the skull forplacementof the transducerwhenscanning. The most commonstandardimagingof neonatesisdone coronallyand sagittally throughthe anterior fontanel.The posteriorandmastoidfontanelsare usedsecondarilyandprovide usefulimages.My experience hasmade use of a 5 MHz lineararray at RGH at the anteriorfontanel.The literature suggests higherfrequencyforpremature infants(7.5MHz) andevenhigherforscans inthe near field(12MHz).¹ The fissuresimportanttothe Sonographerare the sagittal or longitudinal fissure andthe Sylvain fissure.² Midline structuresare importanttoknow todivide rightfromleftandanteriorfromposterior. Midline structuresare: Frontal lobe Cingulate (central) sulcus Cavumvergae Tentorium Vermisof cerebellum Parietal lobe Corpuscallosum Thirdventricle Choroidplexus, thirdventricle Aqueduct Occipital lobe Cavumseptum pellucidum Fourthventricle Brain stem Occipitoparietal fissure
  4. 4. Paramedianstructuresare: Frontal Lobe Frontal horn, lateral ventricle Temporal horn, lateral ventricle Thalamus Choroidplexus Parietal lobe Bodyof lateral ventricle Occipital horn, lateral ventricle Caudothalamic groove Cerebellum Occipital lobe Atriumlateral ventricle choroidplexus Caudate nucleus If you are familiarwiththe plumed Romancenturion helmetof ancientGreece,Macedonia, andSparta (see KeyTermsforexample picture),youcanthinkof the plume as the corpuscallosum, the cavum septumpellucid,cavumvergae andpineal recess canbe considered the plume holder, the face of the helmetasthe thirdventricle,the cheekplates of the helmetconsidered asthe thalamus, the (echogenic) centurion’s bodybelowthe helmetasthe vermis, andthe hypoechoicareaanteriortothe vermisisthe fourthventricle innormal structural circumstances. The visualizationof thiscomplex seriesof structuresdenotesthe midline plane. The sulcii of the frontal and parietal lobesare wavy,branchedhyperechoiclineswiththe cingulated sulcusmovingparallel anteriortothe corpus callosumforabouthalf its length,again,in normal structure. The ventricularsysteminthe braindistributes cerebrospinalfluid (CSF).CSFnormallyflowsfromthe lateral ventricles,throughthe foremenof Monro,throughthe thirdventricle,thenthe aqueductof Sylvius,the fourthventricle,the lateral foramenof Luschkaor medial foramenof Magendie,the basal cisterns, andthe spinal subarachnoidspace. Blockagesinthissystemcanleadto hydrocephalus,sonographicallyseenasexpandedfluid volumesin the affectedventricles.The choroidplexus,mostof whichresidesinthe lateral ventricles,isamajor producerof CSF, alongwiththe ependymal cellsof the ventrical lining.The remainingproductionof CSF happensinthe liningsof the subarachnoidspacesinthe craniumandspine.The ventrical sizescanbe measuredandratiosdeterminedbycomparingsizes. Repeatstudiescanfollow the course of hydrocephalusandshuntingtreatmentaslongascare is maintainedincontinuityof image depthfrom studyto study.¹ The mostcommon sonographicapproachisthroughthe anteriorfontanelle incoronal andsagittal
  5. 5. planes. The coronal imagesare obtainedbysweepingstartinganteriorpositiontoposterior position. The most anteriorimage shouldbe ator anteriorto the frontal hornsof the frontal cortex. The next image shouldinclude the frontal hornsandbifurcationof the internal carotidartery.The thirdshould be throughthe sylvianfissuresandbrainstem.The fourthshoulddisplaythe bodyof the lateral ventricle, choroidplexus,thalmus,vermisof cerebellum, tentoriumcerebelli andcingulate sulcus. The fifthshould displaytentoriumcerebelli, lateral ventricle withglomusof choroidplexus. The most posteriorandlastimage shoulddisplaythe occipitallobe andoccipital hornsof the ventricles. ¹ Sagittal imagesare obtainedbyplacingthe transducerlongitudinallyacrossthe anteriorfontanelle and anglingfromside toside.Midline imageisidentifiedwiththe curvedcorpuscallosumanteriorto the cavum septumpellucidi,the thirdandfourthventriclesandthe echogenicvermisof the cerebellum. Shallow angulations of about10% ineitherdirectiondisplaysthe small lateral ventricles, the cerebral hemispheres,caudate nuclei andcaudiothalmicnotch.Additional angulations to20 degreesdisplaysthe temporal lobesand horns. Thismethodprovidesfive images,minimally. Patientcare includes maintenance of bodytemperaturewithanisolette andwarmingblankets. The gel shouldbe warmed.Handsshouldbe washed,the transducercleanedwithappropriate wipesor alcohol sprayand allowedtodrybefore andafteruse,outof the patient’spresence.Sterilitycanbe offeredbypackingthe transducerwithgel ina sterile gloveortransducercover.Sterile gel is commerciallyavailable,also. Hemorrhage inthe germinal matrix iscommoninpremature infantsof lessthan32 weeksin gestational age.¹ Hypoxia,hypertension,hypercarbia(too muchCO2in the blood),hypernatremia (elevatedbloodsodium),rapidbloodvolume increase,pneumothorax,maternal aspirinuse, prematurity andmultiple gestationscancontribute toepisodesof neonatal germinal matrix hemorrhage.¹ The immature brain tissue of the premature infantishighlysensitivetochangesin pressure. There are three commonlocationsforgerminal matrix hemorrhage:subependymal, intraventricular,orintraparenchymal.The subependymal areaisthe mostcommon.There isa fine networkof bloodvesselsinthe germinal matrix thatexistsduringfetal life.Duringthe maturation processthisnetworkregressestowardsthe foramenof Monrosothat by term, onlya small amountof vesselsexistinthe caudothalmicgroove betweenthalmus andcaudate nucleus.¹
  6. 6. Complicationsof subependymalandintraventricularhemorrhage are intraventricularand extraventicularobstructive hydrocephalus. Necrosisof the periventricularwhite mattermayoccur, termedperiventricularleukomalacia(PVL).PVLinitiallyappearsasanarea of highlyechogenictissue in the parietal lobe adjacenttothe lateral ventriclesorinthe frontal lobes.² Complicationsof intraparenchymal hemorrhage are permanentlydamagedareasof the brainthat can become necrotic, leadingtoporencephaly.¹ Infectiousagents acquiredearlyinapregnancyoftenhave severeresults:fetal death,abortion, and congenital malformationsresultfrominfectionsatcritical timesduringgestations. ¹ The TORCH acronym representsthe mostcommoninfections: toxoplasmagondii, other(suchas syphyllis - aspirochete) rubellavirus, cytomegallyvirusand herpessimplex type II.Calcifications and lesions,oftenperiventricular,are seen withintraparenchymal hemorrhage . Basal gangliaare oftennotedinthe area on bothsidesof the thalamus,below the cingulategyrus,andwithinthe temporal lobes.¹ There are oftencalcificationsinthe basal ganglia associatedwithinfection. Congenital brainmalformationsare extremelycommonrepresentingthe mostcommonanamolies inhumans.¹Malformationscanbe classifiedintothree stages: ¹ Cytogenesis Formationof cellsfrommolecules Histogenesis Formationof cell groupsinto tissues Organogenesis Formationof tissuesintoorgans 1. neural tube formationat3-4 weeksgestation 2. diverticulationof forebrainat5-6 weeks 3. neuronal proliferation/migrationat8-24 weeks Cytogenesisproducestumors:⁹ CytogenesisDisease Tumor Type Li-Fraumeni syndrome Neurofibromatosis-1 Glioma, ependymoma, choroid plexus tumor Glioma Neurofibromatosis-2 Nevoid basal cell carcinoma syndrome Vestibular schwannoma, ependymoma, meningioma Medulloblastoma Tuberous sclerosis Sub-ependymal giant-celltumor Turcot’s syndrome Medulloblastoma Glioblastoma Von-Hippel Lindau disease Hemangioblastoma
  7. 7. Disordersof Histogenesis ¹⁰ Gray mater heterotopia – clumpsof gray matter in wrongpartsof the brain Schizencephaly - abnormal slits,or clefts,in thecerebral hemispheres. Cysts arelined with graymatter Cortical dysplasias – improper neuron tissuemigration withinthe brain Abnormalities of corpus callosum Phakomatoses – such as neurofibromatosis,tuberous schlerosis,ataxiatelangiectasia,Sturge – Weber syndrome,Von –Hippel Lindau disease,incontentiapigmenti, nevoid basal cell carcinomasyndrome Disordersof Organogenesis¹ Malformations Neural tube closure Chiari Malformation DandyWalkerMalformation Agenesisof the corpuscallosum Lipomaof the corpuscallosum Teratoma Diverticulumdisorder Septoopticdysplasia Holoprosencephaly Aventricularcerebrum Proliferationdisorder Microcephaly Sulcation andMigrationdisorders Lissencephaly Schizencephaly Heterotopias Destructive lesions Disorganization Myelinationdisorder Please refertothe PowerPointpresentationentitled: JackieDillman_May2010 ComparisonStudies
  8. 8. Key terms: Anencephaly–cephalicheadof the neural tube failstoclose prenatally,resultinginmissingmajorityof scalp,skull,andbrain.⁴ Brain: Cerebral ventricles Scheme showing relations of the ventricles to the surface of the brain. Drawing of a cast of the ventricular cavities, viewed from above.
  9. 9. A diagrammaticverticalsection through thebrain showing thelocation of the ventricles and the direction of flowof cerebrospinalfluid (CSF).CSFis formed by thechoroid plexuses(CP),mainly in the lateral ventricles, and drainsinto the blood via the arachnoid villi and the spinalnerve roots ⁵ Chiari malformationshave fourclassifications,type IIbeingthe mostcommon: Chiari I downwarddisplacement ofcerebellar tonsilswithout displacement of 4th ventricle or medula Chiari II Arnold-Chiari. menigomyocele; downwarddisplacement ofcerebellar tonsils, caudal displacement of pons, medulla, enlargedforamenmagnum. Elongated 4th ventricle Chiari III High cervical encephalomenigomyocele – containing medulla, 4th ventricle andcerebellum Chiari IV severe hypoplasia without displasement CSF – cerebrospinal fluid Epyndma– the epithelial liningof the ventricularsysteminthe brainandspinal cord.The liningismade of epyndymal cells,havingciliatocirculate andmicrovilli toabsorbcerebrospinal fluid.⁶ Hydrancephaly –conditionof absentcerebral hemispheres,replacedbycystsof CSF. ⁴ Hydrocephalus - abnormal accumulationof cerebrospinalfluidinthe ventriclesof the brain.⁴ Hypoxia– deprivationof oxygentoanyarea Intraparenchymal –amongst/withinbraintissue.
  10. 10. Intraventricular- structurescontainingcerebrospinal fluidinthe brain.⁴ Microcephaly – conditionof headcircumference twostandarddeviationslessthannormal for developmental age andsex. The brainof affectedindividualsisoftenverysmall.⁴ Phakomatoses – disorders of ectodermal origin¹ Porencephaly - cephalicdisordercharacterizedbyabnormal cleftsinthe cerebral hemisphereswith cysts linedwith whitematter.⁴ Romancenturionhelmetexample: ⁸ Septo-optic dysplasia is a congenital malformation syndromemade manifest by hypoplasia(underdevelopment) of the optic nerve and absenceof the septum pellucidum.¹¹ Schizencephaly - cephalicdisordercharacterizedbyabnormal cleftsinthe cerebral hemisphereswith cysts linedwith gray matter.⁴ Subependymal –cell layersurroundingthe lateralventriclesinthe brain.The adultversionof the embryonicforebrain germinal zone.¹
  11. 11. References: 1. Rumack CM, Drose JA:Neonatal andinfant brain imaging, in RumackCM, WilsonSR, JohnsonJA, Charboneau JW (eds): Diagnostic Ultrasound. 3rd ed. St. Louis, MO, Elsevier Mosby, 2005, pp 1623–1701 2. Fox, Traci: Sonography of the Neonatal Brain. JDMS 25:331-348 November/December 2009 3. Callen, Peter:UltrasonographyinObstetrics and Gynecology. 5th editionPhiladelphia, Pa Elsevier Mosby, 2008, pp 363 -389 4. Ventricular system : http://en.wikipedia.org/wiki/Ventricular_system 5. CSF at Answers.com http://www.answers.com/topic/cerebrospinal-fluid?cat=health 6. Jenkins GW, KremnitzCP, Tortora GJ: Anatomyand Physiology, From Science to Life, Hoboken NJ, John Wiley & Sons, Inc., 2007 pp 219, 445-480. 7. Fontanels http://www.innerbody.com/image_skel01/skel49_new_skull.html 8. RomanCenturion helmet http://www.a2armory.com/medievalhelmets/grachhelm.htm 9. Jaclyn Biegel: Cytogenetics and molecular genetics of childhood brain tumors. Neuro-Oncology1, 139-151, April 19, 1999, Doc 98-30 (neuro-oncology.mc.duke.edu) 10. Kundu S., Sharma S.K., Neuroimaging in neonatal congenital anomalies and infections of brain and spine, Journal of Neonatology. Vol. 22, No. 4, October- December 2008, pp 259-266. 11. Septo-optic dysplasia: http://en.w ikipedia.org/wiki/Septo-optic_dysplasia

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