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““MRI in MS: the radiologist perspectiveMRI in MS: the radiologist perspective””

Unidad de Resonancia MagnéticaServicio de RadiologíaHospital Vall d’Hebron

Barcelonaalex.rovira@idi‐cat.org

Àlex Rovira

••ScansScans mustmust bebe technicallytechnically adequateadequate••TheThe simplificationsimplification andand lessless restrictiverestrictive McDonaldMcDonald criteriacriteria maymay ultimatelyultimatelycompromisecompromise diagnosticdiagnostic specificityspecificity (overdiagnosis)(overdiagnosis)••InterpretationInterpretation mustmust bebe donedone byby expertsexperts::

••withwith knowledgeknowledge ofof relevantrelevant clinicalclinical andand laboratorylaboratory informationinformation

Application of the 2010 McDonald MRI criteriaApplication of the 2010 McDonald MRI criteria

gg yy••withwith enoughenough skillsskills toto recognizerecognize thethe fullfull rangerange ofof brainbrain andand spinalspinal cordcord MSMS imagingimagingabnormalitiesabnormalities••familiarfamiliar withwith atypicalatypical featuresfeatures thatthat shouldshould raiseraise thethe diagnosisdiagnosis ofof otherother diseasesdiseases (“red(“redflags”)flags”)

Misdiagnosis  of MS

••CommonCommon ((academicacademic institutionsinstitutions))••MainlyMainly duedue toto improperimproper interpretationinterpretation ofof MRIMRI findingsfindings

dd

Solomon et al. Neurology 2012

••>>2525%% underunder treatmenttreatment

IncreaseIncrease specificityspecificity of MRI of MRI findingsfindings isis stillstill requiredrequired

Situations in which misdiagnosis may occur

Situation

••PreclinicalPreclinical diagnosisdiagnosis

Pitfalls

••Incidental MRI Incidental MRI findingsfindings suggestsuggest MSMS

normal population aged 18normal population aged 18‐‐50 (550 (5‐‐10%)10%)migraine (x4)migraine (x4)

Modified from Rudick and Miller. Neurology 2013

••Diagnosis at Diagnosis at firstfirst symptomsymptom

••MS MS mimicsmimics

••DifficultDifficult whenwhen clinicalclinical presentationpresentation isis atypicalatypical

••e.ge.g. Vasculitis, . Vasculitis, lymphomalymphoma, , hipoxichipoxic‐‐ischemicischemicvasculopathiesvasculopathies, , sarcoidosissarcoidosis, , LymeLyme diseasedisease……

MisdiagnosisMisdiagnosis has has significantsignificant consequencesconsequences::•• PatientPatient carecare•• HealthHealth carecare systemsystem costcost ((overtreatmentovertreatment))

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Diagnostic strategy in patients with multifocal brain T2 Diagnostic strategy in patients with multifocal brain T2 lesions of unknown originlesions of unknown origin

DemographicDemographic datadataFamilyFamily historyhistoryVascular Vascular riskrisk factor factor profileprofileClinicalClinical informationinformation / CSF / CSF analysisanalysisFullFull rangerange ofof imagingimaging abnormalitiesabnormalities

–– Distribution and shape of lesionsDistribution and shape of lesions–– Involvement:Involvement:

callososeptalcallososeptal interfaceinterfaceUU‐‐fibersfibersbrainstem brainstem spinal cordspinal cord

Full Full rangerange of of imagingimaging abnormalitiesabnormalities

Perivenular  topography of MS plaques“Dawson‘s fingers“

venule plaque

Dawson J. Trans Roy Soc Edinb 1916Horowitz et al. AJNR 1989

HR MR venography (SWI)

venule p q

FLAIR* sequence (3T)Central vein visibility 

SWIFLAIR FLAIR*

Diagnostic value of SWI

Hipointensity signals within MS lesions

FLAIR T1 gad SWI

Intralesional susceptibility signal (ISS) 48% of non48% of non‐‐enhancingenhancing MS MS lesionslesions58% of 58% of enhancingenhancing MS MS lesionslesions

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Susceptibility‐weighted imaging

ITSS within lesions

FLAIR

MSMigraine

SWI

MRI features in MSCorpus callosum lesions

MS

Vascular lesions

MS

CADASIL(40%)

SUSAC(100%)

Small‐vessel disease(diabetes)

NMO

Juxtacortical lesionsMRI features in MS

Courtesy of Dr. García‐Merino

T1 GadPDFlairT2

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Cortical / juxtacortical lesionsDouble‐inversion recovery sequences (3.0T)

DIRFLAIRPDT2

Juxtacortical lesions

MS

Double Inversion Recovery sequences

Vascular

Brainstem/cerebellar lesionsMRI features in MS

MRI at 9.4 TCourtesy of T. Naidich LPM in CIS

Spinal cord Sd. ON Brainstem Sd.

Subclinical lesions in 27‐53% of patients with CIS

Spinal cord lesions 83% of patients with early relapsing MS

Prevalence of spinal cord lesions in MS

Spinal cord lesions in 74‐92% of patients with MS

McDonald 2010 criteria fulfill in 29.8% (brain only) and in 34.7%(brain and spinal cord) in CIS (NNS=7)

Sombekke et al. Neurology 2013; O`Riordan et al. JNNP 1998; Dalton et al. JNNP 2003 Lycklama à Nijeholt GJ et al. Brain 1998; Bot et al. Neurology 2004

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Brain MRI with equivocal findings

Bot et al. Radiology 2002Abnormal spinal cord MRI in 74‐92% of patients with MS

MS or incidental findings in a young subject?

FLAIR

Ovoid lesions

Juxtacortical lesions

Juxtacortical lesion

SWI

Subclinical spinal cord lesions

Corpus callosum lesion

Iron within lesions on SWI

MultipleMultiple sclerosissclerosis

Frontal subcortical lesions

No juxtacortical, corpus callosum 

FLAIR

MS or incidental findings in a young subject?

No subclinical spinal cord lesions

plesions

No iron content on SWI

SWI

Incidental Incidental findingfinding

ConclusionsConclusions

ConventionalConventional MRIMRI techniquestechniques,, whichwhich areare highlyhighly sensitivesensitive forfordetectingdetecting CNSCNS demyelinatingdemyelinating plaques,plaques, areare recognizedrecognized asas thethemostmost importantimportant paraclinicalparaclinical tooltool forfor diagnosingdiagnosing MSMS

IncidentalIncidental findingsfindings andand vascularvascular lesionslesions maymay mimickmimick MSMSIncidentalIncidental findingsfindings andand vascularvascular lesionslesions maymay mimickmimick MSMS

MRIMRI patternpattern inin MSMS isis usuallyusually relativelyrelatively specificspecific whenwhen thethe fullfullrangerange ofof signalsignal abnormalitiesabnormalities areare takentaken intointo considerationconsideration

NonNon‐‐conventionalconventional techniquestechniques maymay improveimprove thethe specificityspecificity ofofMRIMRI