新生儿颅脑超声

1、新生儿颅脑超声影像汪元芳MD, ARDMS, ARVTNeurosonography 1Technique, Indication, AnatomyProtocolIVH & PVLSpinal SonographyTechnique and IndicationRoutinely for premature infants at 6 days and 4 weeks and as needed to rule out Intraventricular Hemorrhage and Periventricular Leukomalacia, as well as other abnormali

2、tiesTypically up to 9 months or as long as fontanelle is openUse anterior fontanelle mostly, also transmastoid and posterior for better visualization of the posterior fossa and 4th ventricleHighest frequency transducer to allow sufficient penetration and resolution (curved or vector), linear images

3、to define superficial structuresAnatomyCorpus CollosumCSPCavum VergaeVelum InterpositumVentriclesChoroid PlexusCerebellumCaudate NucleusThalamusSylvian FissuresCircle of WillisCerebral HemispheresBrain CoveringLobes of CerebrumLobes of CerebrumTemporalParietalFrontalOcciptalVentriclesLateral Ventric

4、le-Frontal Horn-Body -Occipital Horn-Temporal HornAnatomyCSF Pathway-Choroid Plexus-Lateral Ventricles-Foramina of Monro -3rd Ventricle-Aqueduct of Sylvius-4th Ventricle-Foramina of Magendie and Luschka-Foramen Magnum AnatomyCovering of BrainSubdural VsSubarachnoidSubarachnoidSpaceSubduralSpaceBESSI

5、(Benign Enlargement of the Subarachnoid Spaces of Infancy)Enlargement of frontal, temporal extracerebral CSF spaces, enlargement of the frontal horns, and macrocephalyWill show bridging cortical veins (to distinguish between subdural collections which are never benign) Subarachnoid VsSubduralSubarac

6、hnoid VsSubdural ProtocolCoronal Images (frontal occipital)Frontal at level of orbitsOrbital BonesFrontal horns Anterior to Foramen of MonroMCA Region (Measure Lat. Vents.)Foramen of MonroPosterior aspect of 3rd ventricle through thalamiCerebellum and Lateral Vents. BodiesTentoriumLaertal Vents. Inc

7、luding Choroid PlexusCortex of occipital lobes and posterior Interhemispheric Fissure (periventricular white matter)ProtocolCoronalMCARegion of Circle of WillisMCAMeasure Lat. Vents3rd VentSylvian FissuresProtocolCoronalThalamiProtocolCoronalCerebellumTentoriumCerebellar VermisProtocolCoronalChoroid

8、 Plexus in Lat. Vents.Periventricular White MatterInterhemispheric Fissure (Falx)Protocol ParasagittalMidline including corpus callosum, cavum, 3rd and 4th vents, vermis, cisterna magnaCaudothalamic grooveFrontal horn of lat. VentBody of lat. Vent including temporal and occipital hornsSylvian fissue

9、Sulci/Gyri lateralProtocolParasagittal3rd Vent.4th Vent.Cerebellar VermisAqueduct ofSylvius Corpus CollosumMidlineProtocolParasagittalCavum VergaeCisterna MagnaVelum InterpositumCavum SeptumPellucidumMidlineProtocolParasagittalThalamusCaudothalamic GrooveCaudate NucleusProtocolParasagittalTemperal H

10、orn of Lat. VentSylvian FissureFrontal Horn of Lat. VentPeriventricularWhite MatterProtocolParasagittalPremature Smooth BrainSulcationTermProtocolTransmastoidView of cerebellum, 4th ventricle, foramen magnumCerebellar hemisphere closer to transducer will have best resolution, thus we image the cereb

11、ellum from both the right and left mastoid fontanellesPosterior fontanelleImage the occipital horns of the lateral ventriclesProtocolPosteriorOccipital Horn of Lat. Vent4th Vent.Cisterna MagnaTransmastoidCerebellumInterventricular Hemorrhage(IVH)Complications of prematurity: IVH and PVLGerminal matr

12、ix consists of proliferating cells that give rise to neuroblasts which migrate out to form the neurons of the cerebral cortex and the basal gangliaHighly vascular, consisting of network of thin-walled capillaries, veins and arteriolesEarly in gestation, germinal matrix forms subependymal lining of e

13、ntire ventricular system. Maximizes in size at 23-24wks, then slowly regresses, involuting 3rd vent and occipital and temporal horns firstDuring end of gestation, only small area remains over caudate nucleus. By 36 weeks, almost completely gone.Germinal matrix hemorrhage in infants is usually venous

14、 in originIVHRisk Factors for IVH- premature infantInstability of Cardiovascular system leading to sudden increases in blood pressureAbsence of autoregulatory mechanism which maintains constant blood flow to brainMechanics of ventilation, tracheal suctioning, pnuemothorax, patent ductus arteriosus,

15、and high inspired oxygen content because they all increase systemic pressure flow to brainIVHClinical FindingsDiminished consciousness, apnea, decreased hematocrit, coma, seizures50% silent, detected by imaging80-90% of IVH occurs within first 4 days of lifeIVHGrade I HemorrhageCoronally, echogenic

16、mass inferolateral to floor of frontal horns and medial to head of caudate nucleusParasagitally, increased echogenicity anterior to caudothalamic grooveUnilateral or bilateral, subependymal, normal ventricle sizesResolving clot undergoes central liquefaction and may form tiny subependymal cystGrade

17、IIVHGrade IIVHGrade 2 HemorrhageIVH, hemorrhage ruptures through subependymal lining into lat. VentsEchogenic material fills part or all of NON-dilated ventricular system, may adhere to choroid and be difficult to distinguishDecreases in size and echogenicity over several weeksSubependymal lining of

18、 vents may develop echogenic lining due to chemical ventriculitisGrade IIIVHGrade IIIVHGrade 3 HemorrhageIVH with ventricular enlargement of one or both lat. VentsMay extend into 3rd, 4th vents, and cavumUsually resolves over 5-6 weeksMay resolve completely or persist as bands or septationsPost-hemo

19、rrhagic hydrocephalus in more than 2/3, usually remains mild-mod, few need shunt placement ( 10%)Grade IIIIVHGrade IIIIVHGrade 4 HemorrhageIVH with extension into the brain parenchyma adjacent to one or both lat. Vents, ventricular dilationCan cause mass effect with midline shiftTypically frontal or

20、 parietal, and unilateral (same side as IVH)If bilateral, usually assymetric- helping to differentiate from nonhemorrhagic ischemic lesions (PVL) which tend to be bilaterl, symmetricalBy 2-3 months, area of encephalomalacia develops, can communicate with ipsilateral lat. Vent which is often dilatedG

21、rade IVIVHGrade IVPeriventricular Leukomalacia(PVL)In premature infant, same risk factors as for IVH. Systemic hypotension causes fall in cerebral perfusion, leading to ischemia, then infarction and ultimately PVLPVL is an ischemic lesion affecting the deep white matter adjacent to trigones of lat.

22、vents and frontal horns near foramen of MonroClinically, hypotonia, seizures, apneic or bradycardiac episodes. 25-40% of very low bw infants (1000g)Increased echogenicity of white matter seen sonographicallyPVLSymmetric or assymetric2-3 weeks after ischemic insult, cystic changes occur cystic enceph

23、alomalaciaLarger area of PVL, great likelihood of hemorrhagicLarger area of PVL, more likely to have cystic formationCerebral atrophy later result of PVL shows as prominent interhemispheric fissures, cerebral sulci, and lat. VentsSpastic diplegia of both legs is classic neurologic sequela of PVL. In severe cases, may affect arms. Also, intellectual and visual deficits can occur.PVLSpinal S