MRI for Guided Right and Left HeartCardiac Catheterization: A ProspectiveStudy in Congenital Heart Disease

ORIGINAL RESEARCH MRI o Guided Righ and Le Hea Ca diac Ca he e iza ion: A P ospec i e S udy in Congeni al Hea Disease Ma i Nie es Velasco Fo e, MRCPh, 1,2,3 *Sébas ien Roujol, PhD, 1 B am Ruijsink, PhD, 1,2 Is ael Val e de, MD, 1,2,3 Phuoc Duong, MRCPh, 1,2 Nick By ne, MSc, 1,4 Sascha K uege , PhD, 5 S e en Weiss, PhD, 5 Youse A a , MD, 6 Su end ana h R. Vee am Reddy, MD, 6 Tobias Schae e , PhD, 1 Ta ique Hussain, PhD, 1,6 Reza Raza i, MD, 1,2 and Kube an Pushpa ajah, MD 1,2 Backg ound: Imp o emen s in ou comes o pa ien s wi h congeni al hea disease (CHD) ha e inc eased he need o diagnos ic and in e en ional p ocedu es. Cumula i e adia ion isk is a g owing conce n. MRI-guided in e en ions a e a p omising ionizing adia ion- ee, al e na i e app oach. Pu pose: To assess he easibili y o MRI-guided ca he e iza ion in young pa ien s wi h CHD using ad anced isualiza ion passi e acking echniques. S udy Type: P ospec i e. Popula ion: A o al o 30 pa ien s wi h CHD e e ed o MRI-guided ca he e iza ion and pulmona y ascula esis ance analysis (median age/weigh : 4 yea s / 15 kg). Field S eng h/Sequence: 1.5T; pa ially sa u a ed (pSAT) eal- ime single-sho balanced s eady-s a e ee-p ecession (bSSFP) sequence. Assessmen : Images we e isualized by a single iewe on he scanne console (in e ac i e mode) o using a comme cially a ailable ad anced isualiza ion pla o m (iSui e, Philips). Image quali y o ana omy and ca he e isualiza ion was e alu- a ed by h ee ca diologis s wi h >5 yea s’expe ience in MRI-ca he e iza ion using a 1–5 scale (1, poo , 5, excellen ). Ca he- e balloon signal- o-noise a io (SNR), blood and myoca dium SNR, ca he e balloon/blood con as - o-noise a io (CNR), balloon/myoca dium CNR, and blood/myoca dium CNR we e measu ed. P ocedu e findings, easibili y, and ad e se e en s we e eco ded. A ac ion o ime in which he ca he e was isible was compa ed be ween iSui e and he in e ac i e mode. S a is ical Tes s: T- es o nume ical a iables. Wilcoxon signed ank es o ca ego ical a iables. Resul s: Nine pa ien s had igh hea ca he e iza ion, 11 had bo h le and igh hea ca he e iza ion, and 10 had single en icle ci cula ion. Nine pa ien s unde wen solely MRI-guided ca he e iza ion. The mean sco e o ana omical isualiza- ion and con as be ween balloon ip and so issue was 3.9 0.9 and 4.5 0.7, espec i ely. iSui e p o ided a signifi- can imp o emen in he ime du ing which he balloon was isible in ela ion o in e ac i e imaging mode (66 17% s. 46 14%, P< 0.05). View his a icle online a wileyonlinelib a y.com. DOI: 10.1002/jm i.27426 Recei ed Aug 17, 2020, Accep ed o publica ion Oc 19, 2020. *Add ess ep in eques s o: M.N.V.F., 3 d Floo Lambe h Wing S Thomas’Hospi al Wes mins e B idge Road, London SE1 7EH, UK. E-mail: mnie es. [email protected] Con ac g an sponso : Welcome Enginee ing and Physical Sciences Resea ch Council (EPSRC) Cen e o Medical Enginee ing a King’s College London; Con ac g an numbe : WT 203148/Z/16/Z; Con ac g an sponso : EPSRC; Con ac g an numbe : EP/R010935/1; Con ac g an sponso : B i ish Hea Foun- da ion (BHF); Con ac g an numbe : PG/19/11/34243; Con ac g an sponso : Na ional Ins i u e o Heal h Resea ch (NIHR) Biomedical Resea ch Cen e awa d o Guy’s and S Thomas’Na ional Heal h Se ice (NHS) Founda ion T us in pa ne ship wi h King’s College London; Con ac g an sponso : NIHR Heal hca e Technology Co-ope a i e o Ca dio ascula Disease a Guy’s and S Thomas’NHS Founda ion T us . F om he 1 School o Biomedical Enginee ing and Imaging Sciences, King’s College London, London, UK; 2 Depa men o Congeni al Hea Disease, E elina London Child en’s Hospi al, Guy’s and S Thomas’NHS Founda ion T us , London, UK; 3 Ca dio ascula Pa hology Uni , Ins i u e o Biomedicine o Se ille, IBIS, Vi gen del Rocio Uni e si y Hospi al/CSIC/Uni e si y o Se ille, Se ille, Spain; 4 Depa men o Medical Physics, Guy’s and S . Thomas’NHS Founda ion T us , London, UK; 5 Philips Resea ch Eu ope, Hambu g, Ge many; and 6 Depa men o Pedia ics, UT Sou hwes e n Medical Cen e , Dallas, Texas, USA Addi ional suppo ing in o ma ion may be ound in he online e sion o his a icle This is an open access a icle unde he e ms o he C ea i e Commons A ibu ion License, which pe mi s use, dis ibu ion and ep oduc ion in any medium, p o ided he o iginal wo k is p ope ly ci ed. © 2020 The Au ho s. Jou nal o Magne ic Resonance Imaging published by Wiley Pe iodicals LLC. on behal o In e na ional Socie y o Magne ic Resonance in Medicine. 1446 Da a Conclusion: MRI-guided ca he e iza ions we e ca ied ou sa ely and is easible in child en and adul s wi h CHD. The pSAT sequence o e ed obus and simul aneous high con as isualiza ion o he ca he e and ca diac ana omy. Le el o E idence: 2 Technical E ficacy S age: 1 J. MAGN. RESON. IMAGING 2021;53:1446–1457. CONGENITAL HEART DISEASE (CHD) is he mos equen ly occu ing congeni al diso de in newbo ns and he mos equen cause o in an dea h om bi h de ec s. 1 Imp o emen s in diagnosis and ea men ha e led o a la ge numbe o pa ien s eaching adul hood, wi h an inc ease o 55% in he p e alence o adul s li ing wi h se e e ypes o CHD in he las decades. 2 This ise in he popula- ion wi h CHD has made he seconda y e ec s om cu en adiog aphic based echniques become mo e e iden , 3,4 A ecen s udy has shown a significan ele a ion in bioma ke s o ch omosomal damage bo h o diagnos ic and he apeu ic ca diac ca he e iza ion p ocedu es, s a ing ha no sa e dose exis s o adia ion in child en. 5 Magne ic esonance imaging (MRI)-guided ca he e iza- ion o e s an al e na i e o x- ay-guided ca diac p ocedu es, a oiding adia ion and p o iding be e so - issue isualiza- ion. In humans, passi e acking echniques ha e been used o diagnos ic pu poses in an inc easing numbe o s udies, wi h isola ed se ies o success ul in e en ions. 6-8 Di e en isualiza ion echniques in ol ing passi e acking ha e been a emp ed using balloon wedge ca he e s. A ca bon dioxide (CO 2 )-filled balloon can be isualized as a signal oid. 6 Con as -based app oaches use dilu ed gadolinium ins ead, which may be isualized by applying sa u a ion p epulses in e mi en ly, 9 a black-blood p epa a ion using flow-sensi i e g adien s, 10 o wi h pa ial sa u a ion (pSAT) p epulses. 11 The la e op ion o e s simul aneous isualiza ion o he bal- loon, ca diac ana omy, and blood pool. Ca diac p ocedu es unde MRI guidance in humans ha e been ca ied ou using a single 2D iewe on he scanne console 6-8 ( e e ed o as in e ac i e mode in his a icle) o by u ilizing an ad anced isualiza ion pla o m in a sepa a e wo ks a ion enabling eal- ime isualiza ion o 3D da a and mul iplane images, such as iSui e (Philips, Bes , he Ne he - lands) o In e ac i e F on End (Siemens Co po a e Resea ch, P ince on, NJ). 12,13 The second op ion has been used o clinical pu poses in elec ophysiology (EP) s udies and igh hea ca he e iza ion o pulmona y ascula esis ance analy- sis in adul and pedia ic pa ien s. 12-17 The pu pose o his s udy was o e alua e he possibili y o pe o ming MRI-guided ca he e iza ion and o assess he quali y o isualiza ion using a p e iously desc ibed pSAT sequence in an in e ac i e mode o embedded in iSui e o op imize isualiza ion o igh and/o le hea ca he e iza- ion in child en (including in an s) and young adul s wi h CHD. Ma e ials and Me hods Thi y- ou consecu i e pa ien s wi h CHD e e ed o pulmona y ascula esis ance (PVR) analysis we e conside ed o he s udy. The p o ocol was app o ed by he Ins i u ional Re iew Boa d. W i en in o med consen was ob ained om all pa icipan s o hei legal ep esen a i es. In Vi o Valida ion The en i e se up was ini ially es ed, op imized, and alida ed using a 3D-p in ed hea phan om. The no mal igh hea o a 2-yea -old pa ien was p in ed o his pu pose. The segmen a ion and s anda d essella ion language (STL) file p epa a ion we e pe o med manually using Mimics so wa e ( . 18.0, Ma e ialise, Leu en, Belgium) and 3-Ma ic Medical ( . 10.0, Ma e ialise). The model was p in ed using polyje echnol- ogy in Tango Plus FullCu e930 ma e ial in a hollow ashion o allow he simula ion o he in e en ion. The in e io ena ca a (IVC) and supe io ena ca a (SVC) we e a ificially elonga ed in o de o acili- a e he phan om expe imen s. The 3D model was hen a ached o a wa e -filled plas ic box using six F ench in oduce s connec ed a each end. Visualiza ion and na iga ion we e es ed using a p e iously desc ibed pSAT sequence 11 in in e ac i e mode o embedded in iSui e. A 5F balloon wedge ca he e was used, infla ed wi h 1–2mL o a 1% dilu ion o gadolinium (Do a em) a he balloon ip o all expe imen s. Each ope a o pe o med he p ocedu e h ee imes. Ca he e i- za ion was pe o med ollowing he same s a egy and ou e as in clinical cases. Fi s , a 3D bSSFP was acqui ed and selec ed imaging planes we e s o ed when iSui e was u ilized. The ca he e was hen na iga ed om he IVC o he igh a ium, igh en icle, main pulmona y a e y (PA), and PA b anches (Fig. 1). A 5-channel ca - diac a ay ecei e coil was used o he expe imen s. Real-Time MRI-Guided Ca diac Ca he e iza ion Imaging was pe o med on a Philips XMR se up (Achie a o Ingenia, Philips, Bes , Ne he lands). This consis s o a 1.5T MRI- scanne and a BV Pulse a o Allu a Cla i y o Ingenia (Philips) ca - diac X-Ray uni . All s udies we e conduc ed unde gene al anes hesia based on clinical need. An app op ia e size balloon wedge ca he e (A ow In l., Reading, PA) and ecei e coil we e used depending on he weigh o he pa ien (Table 1). Access o he igh o le emo al ein and a e y was gained in he x- ay pa o he XMR sui e. Once access was gained, he pa ien was ans e ed o he scanne and an app op ia e size ca he- e was inse ed. The balloon a he ca he e ip was filled in wi h a dilu ion o 1% gadolinium (Do a em, Gue be , F ance) mixed wi h a physiological 0.9% sodium chlo ide solu ion. Balloons we e ini- ially infla ed o a maximal olume as ecommended by he manu- ac u e . Howe e , he olume injec ed in he balloon- ip was May 2021 1447 Velasco Fo e e al.: iCMR in Congeni al Hea Disease adap ed o he size o he na iga ed s uc u es. This was pa icula ly necessa y when app oaching he PA b anches, whe e he size o he essels educed in calibe in ela ion o he diame e o he eeding essel, and whe e s enosis is a common finding in pa ien s wi h CHD. The iSui e pla o m consis s o a PC loca ed nex o he scanne console whe e he so wa e is ins alled, wo mi o ed sc eens (one nex o he iSui e PC in he scanne console oom and one in he scanne oom), and a se o oo pedals. The scanne console and he iSui e PC we e elec onically connec ed and images sen au oma ically in eal- ime. Fo each case, a e su ey and localize s scans, a 3D bal- anced s eady-s a e ee-p ecession (bSSFP) sequence was acqui ed a he beginning o he s udy. Using he 3D bSSFP images impo ed in o iSui e, pa ien -specific imaging planes we e defined o he ollow- ing ana omical iews: bica al (mul iplana e o ma showing he SVC and IVC), 4-chambe , igh en icula ou flow ac (RVOT), igh 3-chambe (R3ch), pulmona y a e y (PA) bi u ca ion, igh and le pulmona y a e ies (RPA and LPA, espec i ely) o igh hea ca he- e iza ion. Le en icula ou flow ac (LVOT), le 3-chambe (L3ch), and ao ic a ch ana omies we e also s o ed o pa ien s needing le hea in es iga ions. P essu es we e measu ed and eco ded ac oss all ca diac chambe s ca he e ized. In h ee cases an MRI condi ional wi e (EP flex Feinwe k echnik, Ge many, 0.03500 diame e and 180 cm leng h) was used. The iSui e sc een in he scanne oom was used o he ope a- o ’s guidance. Real- ime imaging was con olled by he oo pedals. These could be used o swi ch be ween a s anda d single-plane acquisi ion and dynamic in e lea ed acquisi ions o wo o h ee o hogonal imaging planes ha could be displayed simul aneously, and o s a o s op imaging. The ope a o was able o na iga e back- wa ds and o wa ds in he same plane o ien a ion by p essing he pedals, each mo emen ad anced 80% o he p e iously defined slice hickness o he sequence. Fo ca he e iza ion guidance, a p e iously desc ibed pSAT sequence ( epe i ion ime [TR] / echo ime [TE] = 2.65 msec/1.3 msec, flip angle = 60,field o iew [FOV] = 350 ×300 mm 2 , oxel size = 2.2 ×2.5 mm 2 , slice hick- ness = 10 mm, bandwid h = 1250 Hz/pixel, SENSE ac o = 2, pa - ial k-space acquisi ion in he phase-encoding di ec ion = 65%, numbe o phase encoding lines = 40, acquisi ion ime = 106 msec) was used. 11 The pSAT angle o ob ain pa ial sa u a ion was op i- mized o isualiza ion in each case. The slice hickness was adap ed depending on he pa ien ’s weigh and he size o he s uc u es ha needed o be ca he e ized (Table 1). Image Quali y Assessmen and Feasibili y o MRI Ca he e iza ion Image quali y o ana omy and ca he e isualiza ion was e ospec- i ely e alua ed by h ee ca diologis s (I.V., T.H., K.P.) wi h 11, 12, and 10 yea s o expe ience in c oss-sec ional imaging and MRI ca h- e e iza ion, espec i ely, using a 1–5 scale (1, poo , 5, excellen ). 11 Ca he e balloon signal- o-noise a io (SNR), blood SNR, myoca dium SNR, ca he e balloon/blood con as - o-noise a io (CNR), ca he e balloon/myoca dium CNR, and blood/myoca dium CNR we e measu ed o each case, as p e iously desc ibed. 11 Demog aphic da a, diagnosis, mean hea a e and end- idal CO 2 (e CO 2 ) du ing he p ocedu e, adia ion dose and ime, pul- mona y ascula esis ance a es and unde inhaled asodila o s, and ad e se e en s we e eco ded. As pe ins i u ional p o ocol, base- line PVR was assessed unde 30% ac ion o inspi ed oxygen (FiO 2 ) and epea ed wi h inhaled pulmona y asodila o s and 100% ac- ion o inspi ed oxygen when indica ed. Fo each pa ien , we e alua ed he easibili y o MRI-guided ca h- e e iza ion and ac ion o ime du ing MRI ca he e iza ion in which he ca he e was isible in a leas one plane o space. Slice hickness and he pSAT angle used du ing ca he e iza ion we e eco ded. All medical pe - sonnel in ol ed in MRI-guided in e en ions a ou ins i u ions we e ained in MRI sa e y be o e pa icipa ion in clinical scena ios. S a is ical Analysis S a is ical analysis was pe o med wi h IBM SPSS . 20.0 (A monk, NY). Nume ical alues a e p esen ed as mean s anda d de ia ion (SD) unless s a ed o he wise. The ac ion o ime in which he ca he e was isible was compa ed be ween iSui e and in e ac i e mode. A - es was used o es o di e ences be ween he wo guidance app oaches in e ms o ac ion o ime in which he ca he e was isible. Fo ca ego i- cal a iables (sco es), a Wilcoxon signed ank es was pe o med o e al- ua e s a is ical significance. Ca ego ical a iables a e p esen ed as median and ange unless s a ed o he wise. P< 0.05 was conside ed significan . Resul s Demog aphic Fea u es and P ocedu e Findings F om he 34 consecu i e pa ien s ini ially e e ed o PVR s udy, 30 pa ien s we e finally ec ui ed ( wo pa ien s declined en olmen , one pa ien had a pacemake implan ed, and one pa ien was an adul wi hou capaci y o consen ). FIGURE 1: Visualiza ion o he balloon wedge ca he e in a 3D p in ed hea . Tip o he ca he e a he igh a ium (le ), o igin o he le pulmona y a e y (cen e ) and in he igh pulmona y a e y ( igh ). 1448 Volume 53, No. 5 Jou nal o Magne ic Resonance Imaging TABLE 1. Diagnosis, P e ious P ocedu es, Weigh , Slice Thickness, pSAT Angle, Size o Balloon Wedge Ca he e , Coil, and Scanning Me hod Used o Each Pa ien Pa ien Diagnosis P e ious ca diac p ocedu es Weigh (kg) Slice hickness/ pSAT flip angle Hea s uc u es ca he e ized Size o balloon wedge ca he e (F ench)/Use o MRI compa ible wi e Coil Scanning me hod 1 Comple e AVSD Nil 49 10 mm/30IVC, RA, RV, MPA, LPA, LCPW 6/No Ca diac coil In e ac i e 2 a Allagile’s synd ome. Bila e al PAs s enosis Nil 7.5 10 mm/30IVC, RA, RV, MPA, LPA, RPA, RPCW, DAo, AAo, LV 4/No Ca diac coil iSui e 3 DORV, malposi ion o he g ea a e ies William’s Synd ome As hma Uppe ai way obs uc ion (pa ial ocal palsy) •Modified BT shun •VSD closu e, ASO (Lecomp e), excision o subpulmona y s enosis 98 8 mm/50IVC, RA, RV, RPA, MPA, DAo, AAo, LV 6/No Ca diac coil iSui e 4 a Allagile, PAs s enosis Nil 12.2 5 mm/30IVC, RA, RV, MPA, LPA, RPA, RPCW, DAo, AAo, LV 4/No Ca diac coil iSui e 5 Le a ial isome ism In e up ed IVC wi h bila e al azygos con inua ion PAPVD (RPV o igh sided a ium), small ASD, pe imemb anous VSD Pulmona y hype ension •Comple e su gical epai 14 7 mm/30IVC, RA, RV, MPA, LPA, RPA, RPCW, DAo, AAo, LV 4/No Ca diac coil In e ac i e 6 TGA, AP window Nil 11 7 mm/30IVC, RA, RV, MPA, LPA, LPCW, Ao a 4 ( ) & 5 (a)/No Ca diac coil iSui e 7 AVSD Nil 6.5 7 mm/40IVC, LA, RA, RV, LV, MPA, LPA, RPA, RCPW 4/No Flex M iSui e 8 TOF •Balloon dila a ion o pulmona y al e •Su gical epai o TOF & LPA econs uc ion •Balloon dila a ion o igh uppe , RUPA, RMPA &RLPA •Balloon dila a ion o LPA & s en inse ion 33 10 mm/30- 45 IVC, RA, RV, MPA, RPA, (LPA a emp ed bu obs uc ed), RCPW 6/No Ca diac coil iSui e 9 HLHS Single en icle –s/p Fon an 45 8 mm/40IVC, LL, SVC, RPA, LPA, LPCW, RA, LA, RV 6/No Ca diac coil iSui e 10 TAPVD, se e e RPV s enosis •Su gical epai o TAPVD •Balloon dila a ion o RUPV 25 7 mm/40IVC, RA, RV, LPA, RPA, RPCW, LPCW, DAo, AAo, LV 5 ( ) & 4 (a)/No Ca diac coil iSui e May 2021 1449 Velasco Fo e e al.: iCMR in Congeni al Hea Disease TABLE 1. Con inued Pa ien Diagnosis P e ious ca diac p ocedu es Weigh (kg) Slice hickness/ pSAT flip angle Hea s uc u es ca he e ized Size o balloon wedge ca he e (F ench)/Use o MRI compa ible wi e Coil Scanning me hod 11 Secundum ASD, Pe imemb anous VSD, T21 Nil 6 7 mm/40IVC, RA, LA, RV, MPA, LPA, RPA, LPCW, 4/No Flex L iSui e 12 PAPVD (LU&LMPV o innomina e ein), pe imb anous VSD Nil 5 7 mm/40IVC, RA, RV, LPA, RPA, LPCW, RPCW. DAo, AAo, LV 4/No Flex L iSui e 13 AV disco dance, DORV •Single en icle –s/p Fon an 60 8 mm/30IVC, LL, SVC, RA, LA, RV, RPA, LPA, LPCW 6/No Ca diac coil iSui e 14 PAPVD (RPV o RA), secundum ASD •Coil embolisa ion o MAPCAs 5.5 N/A IVC, RA, RV, MPA, LPA (RPA a emp ed bu obs uc ed), LA, LV, DAo, Asc Ao 4/No Ca diac coil N/A 15 HLHS Single en icle –s/p Fon an 20 7 mm/30IVC, LL, SVC, RPA, LPA, LPCW, RA, LA, RV 6/No Ca diac coil iSui e 16 C iss-c oss hea , ASD, se e e subpulmona y and pulmona y al e s enosis Nil 19 N/A IVC, RA, RV, MPA, RPA, LPA, RPCW 5/No Ca diac coil N/A 17 Disco dan AV connec ions, conco dan VA connec ions •Single en icle –s/p Glenn 11.5 8 mm/30IVC, RA, LV, SVC, RPA, LPA, LPCW 4/No To so coil In e ac i e 18 HLHS •Single en icle –s/p Fon an 21.3 8 mm/40IVC, LL, SVC, RPA, LPA, LPCW, RA, LA, RV 6/No To so coil In e ac i e 19 HLHS •Single en icle –s/p Glenn 18 8 mm/40IVC, RA, RV, SVC, RPA, LPA, LPCW 5/No To so coil In e ac i e 20 Ao ic Coa c a ion, mode a e sized VSD, congeni al le diaph agma ic he nia and le lung hypoplasia, 13 ch omosome dele ion, scoliosis •Ao ic coa c a ion epai 7 10 mm/40IVC, RA, RV, MPA, RPA, RPCW, LPA, LPCW, LV, AAo, DAo 4/Yes Ca diac coil iSui e 21 Common a ium, iny muscula VSD •ASD closu e 34 10 mm/40IVC, RA, RV, MPA, RPA, LPA, LPWC 6/Yes Ca diac coil iSui e 22 HLHS, Le pulmona y ein s enosis •Single en icle –s/p HemiFon an •LPV s en 13 N/A SVC, LPA, LPCW, RPA, RPCW 4/No Ca diac coil N/A 23 Pe imemb anous en icula sep al de ec Nil 15 10 and 5 mm/ 40 IVC, RA, RV, MPA, LPA, RPA, RPCW, LV, AAo, DAo 5/No Ca diac coil iSui e 24 HLHS •Single en icle –s/p Fon an •LPA s en 24 N/A IVC, LL, LPA, RPA, RPCW, RA, RV, AAo, DAo 5 ( ) & 4 (a)/No Ca diac coil N/A 1450 Volume 53, No. 5 Jou nal o Magne ic Resonance Imaging TABLE 1. Con inued Pa ien Diagnosis P e ious ca diac p ocedu es Weigh (kg) Slice hickness/ pSAT flip angle Hea s uc u es ca he e ized Size o balloon wedge ca he e (F ench)/Use o MRI compa ible wi e Coil Scanning me hod 25 a HLHS •Single en icle pallia ion –s/p Fon an 72 10 mm/40IVC, LL, SVC, RPA, LPA, LPCW, RA, RV, AAo, DAo 6F ( & a)/Yes Ca diac coil iSui e 26 He e o axy, dex oca dia, AVSD, sup/in en icles, pulmona y a esia wi h disconnec ed PAs •Uni ocaliza ion o MAPCAs + BTS 7.6 8 mm/30IVC, RA, LA, RV, LV, DAo, AAo, BTS, LPA, RPA 5 ( ) & 4 (a)/No Flex M In e ac i e 27 TOF/absen pulmona y al e •Ao homog a , LeComp e maneu e 13.3 10 mm/40IVC, RA, RV, MPA, LPA, RPA, RCPW 5/No Flex M In e ac i e 28 TGA, hypoplas ic RV •Single en icle –s/p Fon an 17.4 10 mm/40IVC, LL, SVC, LPA, RPA 6/No Flex M In e ac i e 29 HLHS •Single en icle –s/p Glenn 13.4 8 mm/40IVC, RA, RV, SVC, RPA, LPA, LPCW 5 ( ) & 4 (a)/No Flex M In e ac i e 30 HLHS •Single en icle –s/p Glenn 15.4 8 mm/40IVC, RA, RV, SVC, RPA, LPA, LPCW 5 ( ) & 4 (a)/No Flex M In e ac i e The size o he shea h e e s o he enous access unless specified o he wise. a These pa ien s unde wen dobu amine s ess s udy as well as PVR analysis. (A) = a e ial access; ASD = a ial sep al de ec ; AAo = ascending ao a; AV = a io en icula ; AVSD = a io en icula sep al de ec ; BTS = Blalock-Taussig shun ; DAo = descending ao a; DORV = double ou le igh en icle; HLHS = hypoplas ic le hea synd ome; IVC = in e io ena ca a; LA = le a ium; LL = la e al unnel; LPA = le pulmona y a e y; LPCW = le pulmona y capilla y wedge; LPV = le pulmona y eins; LV = le en icle; MAPCA = majo ao opulmona y colla e al a e y; PAs = pulmona y a e ies; RA = igh a ium; RPA = igh pul- mona y a e y; RPCW = igh pulmona y capilla y wedge; RUPA = igh uppe pulmona y a e y; RMPA = igh middle pulmona y a e y; RLPA = igh lowe pulmona y a e y; RV = igh en icle; RVOT = igh en icula ou flow ac ; SVC = supe io ena ca a; TGA = ansposi ion o he g ea a e ies; TOF = Te alogy o Fallo ; ( ) = enous access; VSD = en icula sep- al de ec . May 2021 1451 Velasco Fo e e al.: iCMR in Congeni al Hea Disease Demog aphic ea u es and hemodynamic findings a e summa ized in Table 2. Among all ec ui ed pa ien s, 11 we e emales. The median age was 4 yea s ( ange: 2 mon hs o 39 yea s), median weigh was 15.2 kg ( ange: 5–98 kg), median body su ace a ea (BSA) was 0.65 m 2 ( ange: 0.27–2). Twen y pa ien s had p e ious majo ca diac su ge y. Th ee needed a dobu amine s ess s udy in addi ion o base- line PVR analysis. Se en unde wen igh hea ca he e iza- ion, 11 needed bo h igh and le hea assessmen , and he es o he pa ien s 12 we e single en icle ana omies needing ca he e iza ion o he Fon an (se en cases) o HemiFon an/ Glenn (fi e cases) ci cula ion and in aca diac p essu es. In ou ec ui ed pa ien s a he beginning o he s udy, MRI guidance was no pe o med owing o he p edic able need o a wi e in a pa ien wi h a c iss-c oss hea and se e e al a and sub al a pulmona y s enosis, he pa ien ’s clinical ins abili y (pe sis en pulmona y hype ensi e c isis), and he a i ac caused by he exis ing s en s in he pulmona y essels in wo pa ien s wi h single en icle ci cula ion. The mean adia ion dose and ime we e 0.42 0.58 mGym 2 and 10.02 11.36 minu es, espec i ely. The o al p ocedu e ime (skin in –skin ou ) was 219 52 minu es. The median baseline pulmona y ascula esis ance was 2.3 WU.m 2 ( ange: 0.28–32.6). These alues educed o a TABLE 2. Summa y o Demog aphic Fea u es and Ca he e iza ion De ails in Rec ui ed Pa ien s Age (median, ange) 4 yea s (2 mon hs o 39 yea s) Body su ace a ea (median, ange) 0.65 m 2 (0.27–2) Weigh (median, ange) 15.2 kg (5–98) Heigh (median, ange) 102 cm (58–175) P e ious ca diac p ocedu e 20/30 pa ien s Hea a e 98 28 bpm Ca he e isa ion ime (skin in-skin ou ) 219 52 minu es Indexed adia ion dose 0.42 0.58 mGym 2 Radia ion ime 10.02 11.36 minu es Measu emen s a e shown as mean SD unless s a ed o he wise. FiO2 = ac ion o inspi ed oxygen; iNO = inhaled ni ic oxide; ppm = pa s pe million; PVR = pulmona y ascula esis ance. FIGURE 2: E ec o changes in pSAT angle (30,40 , and 50) and slice hickness (5, 7, 8, and 10 mm) in balloon, blood, and myoca dium SNR (a,b) and balloon/blood, balloon/myoca dium and myoca dium/blood CNR (c,d) ac oss di e en pa ien s. 1452 Volume 53, No. 5 Jou nal o Magne ic Resonance Imaging median PVR o 1.9 WU.m 2 ( ange: 0.63–27) in esponse o inhaled asodila o s. Indi idual Adjus men o he pSAT Sequence in Clinical Cases The in i o e ec o changes in pSAT angle (30,40 , and 50) and slice hickness (5, 7, 8, and 10 mm) in balloon, blood, and myoca dium SNR and balloon/blood, balloon/ myoca dium and myoca dium/blood CNR a e summa ized in Fig. 2. Only one se o pSAT angle/slice hickness was acqui ed o each subjec ; he e o e, each plo ep esen s a di - e en pa ien . Slice hickness and pSAT angle o each pa ien a e desc ibed in Table 1. Bo h ea u es we e adap ed indi idually. In one case, he slice hickness was 5 mm. This was a small pa ien (weigh 12 kg) wi h se e e PA b anches s enosis FIGURE 3: Images acqui ed wi h iSui e in a pa ien wi h Te alogy o Fallo and LPA s en . An inc ease in he pSAT angle om 30 ( op image) o 45(bo om image) imp o ed he conspicui y o he balloon- ip by inc easing he con as be ween blood and balloon. May 2021 1453 Velasco Fo e e al.: iCMR in Congeni al Hea Disease associa ed wi h Allagile’s synd ome (minimum LPA and RPA diame e we e 5 and 6 mm, espec i ely). Fo he es o he cases, he slice hickness anged om 7–10 mm and was adap ed acco ding o he pa ien ’s weigh and ca diac s uc- u es’size. The pSAT angle o achie e pa ial sa u a ion was also op imized in each case, a ying om 30 o 50.In pa ien s wi h small pulmona y a e ies, he u bulen flow p e en ed depic ion o he balloon ip using low pSAT angles. This was pa icula ly e iden in a pa ien wi h Te alogy o Fallo and LPA s en , in whom bo h pulmona y a e ies we e slende all along hei cou se. An inc ease in he pSAT angle om 30 o 45imp o ed he isualiza ion and allowed con- inua ion o he s udy (Fig. 3, Video S1 in he Supplemen al Ma e ial). A slice hickness o 20 mm and a pSAT angle o 120was used in wo cases o find he balloon du ing eal- ime MRI ca he e iza ion. Once he balloon was loca ed, he plane o isualiza ion was ans e ed up o he balloon ip, and he slice hickness and pSAT angle con e ed o he one ini ially selec ed. The olume injec ed in he balloon a he ip o he wedge ca he e was adap ed no only o each pa ien bu acco ding o he size o he na iga ed s uc u es du ing he cou se o he case. Al hough ini ially infla ed o he maximum olume ecommended by he manu ac u e , in nume ous occasions i had o be pa ially defla ed o c oss he pulmo- na y al e o o ca he e ize he pulmona y b anches. Visualiza ion Du ing Real-Time MRI-Guided Ca he e iza ion The iSui e pla o m was used in 16 pa ien s. In 10, he pSAT sequence was used in in e ac i e mode in he scanne console, as he iSui e was no a ailable. In one pa ien , ca he e enous access was om he neck essels wi h simul aneous need o a le hea ca he e om a emo al a e ial app oach. This lim- i ed sa e isualiza ion o he iSui e sc een om he head end o he MRI bo e in he cu en se -up o he labo a o y. Visualiza ion o he balloon a he ip o he ca he e was achie ed in all he s udies. Du ing eal- ime MRI ca he- e iza ion, he balloon was isible h oughou 57 21% o he scanning ime. The iSui e pla o m allowed o isualiza- ion in he h ee planes o space, wi h a significan imp o e- men in he ime du ing which he balloon was isible in ela ion o he in e ac i e imaging mode on he scanne console (iSui e: 66 17% s. in e ac i e mode: 46  14%, P< 0.05). O e all, he sco e o balloon/blood con as and ana- omical isualiza ion was good o excellen , achie ing a median o 4 ( ange: 2–5) and 5 ( ange: 2–5), espec i ely. High sco es o bo h we e ob ained independen o he use o he pSAT sequence embedded in iSui e o as in e ac i e mode in he scanne console (Wilcoxon es : compa ison be ween balloon/blood con as wi h iSui e o in e ac i e mode, P= 0.385; ana omical isualiza ion, P= 0.5). Th ee pa ien s ecei ed a sco e o 2 o ana omical isu- aliza ion. O no e, all h ee we e a he ex eme side o he weigh ange in ou popula ion ( wo o hem we e less han 8 kg, one o hem was o e 95 kg). A o al o 91% o sco es gi en o ana omy depic ion we e ≥3; he weigh ange o hese pa ien s was 10–60 kg. Al hough no significan di e - ence was no ed, a end o ob ain highe sco es was ound o ana omical isualiza ion in ela ion o pa ien ’s weigh (P= 0.053). Simila alues we e obse ed when balloon/ blood con as sco ing was compa ed among di e en weigh g oups (P= 0.483) (Fig. 4). Two pa ien s in whom he MRI ca he e iza ion was guided wi h he pSAT sequence on in e ac i e mode ecei ed a sco e o 2 o con as . In all p ocedu es guided by iSui e, con as be ween balloon and pa ien ’s ana omy was sco ed FIGURE 4: Mean sco es o ana omical isualiza ion and balloon/ blood con as sco es acco ding o pa ien ’s weigh . Be e sco es we e achie ed o pa ien s wi h weigh be ween 10 and 60 kg. FIGURE 5: To al pe cen age o pa ien s ecei ing a sco e o 2 (9 and 5%), 3 (23 and 12%), 4 (42 and 23%), and 5 (26 and 59%) o ana omical and balloon/blood con as isualiza ion, espec i ely. 1454 Volume 53, No. 5 Jou nal o Magne ic Resonance Imaging