ISNVD Abstract Book

useful in assessing blood products such as microbleeds and hemorrhagespossibly due to traumatic
braininjury,vasculardementia,orMS.SWIMRAcanrevealarteriesandveinsontheorderofafew
hundredmicronsbymeansofadualechosequence.MRAandMRVdatacanbeobtainedatthesame
time.
Formoreconventionalimaging,T2WIisusedtoshowtissuewithlongT2componentssuchasedema,
CSF,tumors,andMSlesions.3DT2FLAIRisusedbecausetheimageshavesuppressedCSFsignal.FLAIR
showsperiventricularlesionswellwithouttheinterferencefromCSF.Lesionquantityandvolumecan
lsobeassessedwithFLAIR.Eventuallyitmaybepossibletocomparelesionvolumewithbloodflowor
patient’sphysiologicalchangesovertime.T1WIisusedattwopartsofthescanningprotocoltoimage
the head: initially before contrast agent injection, and after contrast agent injection.Lesions that
enhancepostcontrastareconsideredasacute.
PWIisusedtoevaluatethehemodynamicsofthebrain.Fromthisdataitispossibletoassessmean
transittime(MTT)whichisthetimeittakesforcontrastagenttopassthroughthemicrovasculature;the
cerebralbloodvolume(CBV)andthecerebralbloodflow(CBF).
Notallthesescansneedtoberunoneverypatient.Thefullprotocolbelowisusedinaresearchmode.
Whilethefullprotocolscantakesroughly1hour,22minutestorun,thereareshorterprotocolswith
andwithoutcontrastthatcanreducethescantime.Removingthecontrastdependentsequencescan
reducethetotalscantimetoapproximately52minutes.Foraposttreatmentscanwithoutcontrastand
azygousdata,thescantimewouldbereducedtoapproximately34minutes:lesions,ironcontent,
anatomyfrom2DTOFMRV,andbloodflowwouldstillbeabletobeassessed.
ScanningProcedure
Initially,registerthepatientalongwithhis/herheightandweight.Thisplaysanimportantrolein
flowquantification(FQ).
Activateappropriate(head,neckandspine)coilsforimagingtheregionofinterest.
Makesuretoputthepulsetriggeronthesubject's(left/right)indexfingerorforabetterflow
quantificationcardiacgatingcanbeused.
Initially,westartimagingtheheadusingSWI,T2,MPRAGE,FLAIR,VIBE,andPWIsequences.
Make sure to use the head and neck coils. Inject 5cc of contrast agent on the 10 th
measurementofPWIsequence.
Later, move the table to center at the neck and acquire T2, 3D CE MRAV, and flow
quantification (FQ) sequences. Make sure to use the head neck coils. Inject the remaining
contrastagentonthe3 rd measurementof3DCEMRAV.
The FQ plane will be set perpendicular to the CSF flow at C2/C3 necklevel with a VENC of
10cm/sec,andsetperpendiculartotheinternaljugularveins(IJV’s)attheC2/C3,C5/C6and
C7/T1necklevelswithavencof50cm/sec.
Next,movethetablecenterbacktotheheadandacquirethedatausingthepostgadolinium
sequencesVIBE,andMPRAGE.
Toimagetheazygous,movethetabletocenteratthemidsternum.Usetheneckandspine
coils.Acquire2DTOFMRVandFQsequences.UseaVENCof50cm/secfortheFQsequence.