in preterm infants with real-time ultrasound

Transcription

1 Arhives of Disese in Childhood, 1981, 56, 9-94 Mesurement of the growth of the lterl ventriles in preterm infnts with rel-time ultrsound MALCOLM I LVN Deprtment ofpeditris nd Neontl Mediine, Institute of Child Helth, Hmmersmith Hospitl, London SUMMARY Rel-time ultrsound ws used to mke ext mesurements from the lterl wll of the body of the lterl ventrile to the flx (the ventriulr index) in 273 infnts of vrying gesttionl ges The mesurement performed in n xil plne through the temporoprietl bone orrelted losely with n tul mesurement mde in oronl plne in 5 infnts A ross-setionl entile hrt ws drwn up of the norml rnge for this mesurement from 27 to 42 weeks' postmenstrul ge A further hrt showing the rte of hnge of the ventriulr index llowed growth of the ventriles to be ssessed in longitudinl mnner Use of these hrts permits erly detetion of hydroephlus or dilted ventriles seondry to erebrl trophy Visulistion of the erebrl ventriles is essentil in investigtion of the hild with suspeted hydroephlus Four redily-vilble methods exist: eho enephlogrphy nd ir ventriulogrphy, nd more reently omputerised tomogrphy nd reltime ultrsound ho enephlogrphy using A-mode equipment produes relible mesurements of midline strutures suh s the 3rd ventrile,1-3 but mesurement of lterl ventriles is more diffiult nd time onsuming4-6 Air enephlogrphy is highly invsive nd produes rteftul hnges in lterl ventriulr size,7 8 mking its use severely limited The dignosis of hydroephlus on omputerised tomogrphy is often obvious,9 however little informtion is vilble on the norml rnge of ventriulr size' 1' nd erly hydroephlus or dilted ventriles of mild degree my be missed Fukuym et l'2 gve rnge for ventriulr rtio in norml hildren, lthough only 6 infnts ged below I yer were studied Ventriulr size hs been mesured prentlly in n effort to dignose erly fetl hydroephlus,'3 nd postntlly during the first yer of life Studies hve shown good orreltion between the lterl ventriulr rtio mesured both by A-sn eho-enephlogrphy nd omputerised tomogrphy in infnts'516 Reently, rel-time ultrsound hs been widely epted s relible method to dignose intrventriulr hemorrhge nd hydroephlus in infny'7 18 There re s yet no dt on the size of the ventriulr systems in preterm infnts, nd for this reson study of both ross-setionl nd longitudinl ventriulr growth ws undertken nd entile hrts onstruted Methods A Krnzbuhler ADR liner rry rel-time ultrsound mhine ws used to visulise the body of the Fig 1 (Right) xil sn (S MHz trnsduer) through the temporoprietl bone showing the mesurement from the midline eho to the lterl ventrile-the ventriulr index (A) (Left) oronl sn (7 MHz trnsduer) through the fontnelle showing the mesurement from the lterl-most extent of the lterl ventrile to the flx (A) 9 Arh Dis Child: first published s 11136/d56129 on 1 Deember 1981 Downloded from on 21 July 218 by guest Proteted by opyright

2 s Mesurement of the growth of the lterl ventriles in preterm infnts with rel-time ultrsound 91 lterl ventriles in 273 term nd preterm infnts With this higher frequeny trnsduer, the flx nd Snning ws performed with 5 MHz trnsduer ventriul r system ould be lerly visulised, nd pled ginst the firly flt temporoprietl region n tul mesurement mde from the flx to the of the infnt's hed t the level of the outer nthus most lterl extent of the lterl ventrile (Fig 1) of the eye nd the helix of the er'8 The trnsduer is Hely's method of estimting the men nd kept prllel to this line nd is moved upwrds until stndrd devition (SD) by 'ensoring' the lowest the body of the lterl ventriles is seen most lerly nd highest 5% of the mesurements for eh (Fig 1) The distne between the eho from the gesttionl ge group ws used19 The hnge in VI flx nd the ontrlterl ventriulr wll is mesured using omnidiretionl lipers fitted to the lulted nd expressed s veloity (mm/2 weeks) from birth to the end of the seond week of life ws mhine The system veloity ws 154 metres/seond This ws repeted for suessive 2-week intervls Two mesurements were mde t eh exmintion until the infnt ws 28 weeks old, irrespetive of nd verged As this is not true mesurement of gesttion The men nd SDs of eh veloity the size of the lterl ventrile t this point, this mesurement during 2-week intervl ws lulted distne is referred to s the ventriulr index (VI) using this method In order to detet ny vrition Seril mesurements were performed on mny in ventriulr size ourring before the end of the infnts until the skull hd beome suffiiently seond week of life, the hnge in VI t ge 7 dys minerlised to mke visulistion impossible, ws lulted, s ws the men nd SD generlly between ges 6 nd 9 months Attenution of ultrsound through the temporoprietl bone my use distortion nd mke Subjets mesurement of VI in this plne unrelible For this The infnts studied rnged from 26 to 42 weeks' reson the VI ws ompred with trnsfontnelle gesttion Some (n = 5) were norml term infnts oronl sn using 7 MHz trnsduer in 5 infnts (gesttionl ge 37 to 42 weeks) exmined on the O 15 : m X O 14 OD % m 88,or D, 12 - _ -U COD o m -, _ U -b 4 _ m ; 1 S 9- q l - 4 _ o J1 28 Ī I I I I I Postmenstrul ge (weeks) Fig 2 Distribution of ventriulr index by gesttionl ge Open irles represent 'norml' infnts exmined on the postntl wrd The men is shown by horizontl br Closed irles represent infnts dmitted to the neontl unit for premturity or linil problems Arh Dis Child: first published s 11136/d56129 on 1 Deember 1981 Downloded from on 21 July 218 by guest Proteted by opyright

3 92 Levene postntl wrd fter informed prentl onsent The remining 223 infnts hd been dmitted to neontl unit for observtion or tretment The first sn ws performed within the first 6 dys of life, nd in 81 % of them ws within 48 hours of birth If n infnt hd ultrsound evidene of intrventriulr hemorrhge or erebrl trophy on the first sn he ws exluded from the study; of the 273 infnts, only 8 subsequently developed intrventriulr hemorrhge fter n initilly norml sn Fig 2 shows the distribution of infnts by gesttionl ge nd their VI mesurements Thirtythree bbies died during the ourse of the study nd 9 (48 %) of the survivors returned to the follow-up lini nd were subsequently resnned t eh visit nd mesurements of VI mde Results The men nd SD were lulted weekly s desribed from 3 to 4 weeks of gesttionl ge Results for 26 nd 27, 28 nd 29, nd 41 nd 42 were onsidered together beuse of the smll numbers (Fig 2) Fig 3 shows the reltionship between the tul mesurement on oronl sn from the lterl-most extent of the lterl ventrile to the flx nd the VI mesured through the temporoprietl bone (r - 98) A ross-setionl entile hrt of the VI shows the smoothed 3rd, 5th, nd 97th entiles for this mesurement over the gesttionl ges 26 to 42 weeks (Fig 4) Fig 5 shows the smoothed growth veloity during 2-week intervls from birth to 28 weeks' hronologil ge, irrespetive of gesttion 2- x ` C Atul ventriul,r nesurement (mm) Fig 3 Correltion of ventriulr index ( mm) with tul ventriulr mesurement (mm) C - 1- o Vn - I I! g - I Postmenstrul ge (weeks) Fig 4 Cross-setionl hrt of ventriulr index Smoothed entiles re 3rd, 5th, nd 97th x W 5 C- ) ~ I Jo, I 4 8 Age from birth (weeks) IT--" Fig 5 Chrt showing growth veloity from ge 2 weeks Dotted lines represent hnge in ventriulr index during the first nd seond weeks of life Smoothed entiles re 3rd, 5th, nd 97th The broken line represents the hnge in VI from birth to the end of the first week, nd from 7 dys to the end of the seond week A omprison between men growth rtes in less mture bbies (less thn or equl to 33 weeks) nd those of 34 weeks or more is shown in Fig 6 During the first 6 months of life there is no signifint differene between the men vlues for the first 1 weeks nd from the 2th week of life Between 12 nd 18 weeks, y=39+198x the rte of inrese of the VI in the less mture r=q98 bbies is slightly higher thn in the more mture ones nd the differene is signifint during eh of those 6 weeks (P<5) Infnts were mesured three times during the 25 3 ourse of n hour (by MIL) nd the VI did not vry by more thn 1 mm Inter-observer error depended on the experiene of the observer The Tble shows two estimtes of VI mesurements on 1 infnts 42 mmmmmm Arh Dis Child: first published s 11136/d56129 on 1 Deember 1981 Downloded from on 21 July 218 by guest Proteted by opyright

4 _ +21 S + 1 _ o -1 Mesurement of the growth of the lterl ventriles in preterm infnts with rel-time ultrsound 93 I # i I I I I I I I I Ae from birth (weeks) Fig 6 Comprison of the men (± SD) for hnge in ventriulr index in preterm infnts 33 weeks nd below (losed irles) with more mture infnts of 34 weeks nd over (open irles) Asterisk represents signifint differene between the mens (P< 5) Tble stimte of inter-observer error by 2 experiened ultrsonogrphers Cse First observer Seond observer (MIL) (MRL) 1 9,9 9,9 2 9,9 9,9 3 11,11 11,11 4 1,1 1,9 5 8,9 9,9 6 1,1 1,9 7 11,12 11, ,12 12, ,12 12, ,11 11,11 performed t different times on the sme dy by two experiened observers (MIL nd MRL), eh with more thn 6 months' snning time Disussion Use of rel-time ultrsound provides sfe, rpid, nd onvenient method to mesure the size of the lterl ventriles In order to ssess the true prevlene of dilted ventriles, enlrgement beyond norml rnge must be shown This study provides suh rnge of ventriulr size for vrious gesttionl ges, thus llowing those infnts in whom this mesurement is more thn 2 SDs bove the men to be identified Longitudinl growth veloity hrts for ventriulr size permit rte of hnge in ventriulr size in n individul infnt to be losely monitored in order to detet bnorml rtes of enlrgement This desription provides ventriulr growth dt in only one diretion but mesurements in other positions re diffiult The shpe of the erebrl ventriles is omplited nd hnges with brin mturtion To monitor hnges in size of this system, one or number of referene points must be used These should be redily identifible, should be onstnt in position, nd should not vry in shpe between ptients The oipitl poles of the lterl ventriles re generlly the lrgest prt of the entire ventriulr system, however no onvenient lndmrk exists nd there my be onsiderble vrition in shpe of this struture2 The body of the lterl ventrile is esily essible with ultrsound through the nterior fontnelle nd is symmetril in shpe nd position There is ler mximum distne between the most lterl extent of the ventrile nd the flx whih n rpidly be mesured Chnges in size of the body of the lterl ventrile pper losely to mirror hnges within the entire lterl ventriulr system, nd suh hnges n be losely monitored Although the mesurements my be mde rpidly nd gree well between the sme observer nd different observers, experiene is neessry before onsistent reproduibility is hieved A new investigtive tehnique requires prtie but relible mesurements should be obtined in short time by user fmilir with ultrsound methods In the pst, the mesurement of the lterl ventriulr size hs usully been expressed s rtio to the skull dimeter vns7 introdued the muh used enephlogrphi rtio for estimting the size of the erebrl ventriles in ir-enephlogrphy nd this hs subsequently been used in omputerised tomogrphy snning2' A modifition of it, hs been dopted in ultrsound mesurements of ventriulr size in infnts'5 22 More reently, doubt hs been st on the vlue of the vns's rtio nd diret mesurement of the ventriulr size reommended23 In this study, the very lose orreltion between the tul mesurement of ventriulr size mde on oronl setion nd the ventriulr index permits the VI to be used s vlid mesurement of true ventriulr size nd mkes unneessry the use of rtio whih is more limited in terms of monitoring growth Chnge in the VI in the neonte shows ler pttern whih does not vry to ny gret extent with the mturity of the infnt There is initilly redution in size of the lterl ventriulr mesurement during the first week of life Signifint shrinkge of hed size during the first week in infnts weighing less thn 2 kg hs been reported,24 nd in ddition, redution in erebrl blood flow25 nd flututions in intrrnil pressure26 lso our during the first few dys of life The preise reson for these hnges is not ler, but redution in size of the lterl ventriles during this time is not unexpeted The most rpid inrese of the VI ours from the end Arh Dis Child: first published s 11136/d56129 on 1 Deember 1981 Downloded from on 21 July 218 by guest Proteted by opyright

5 94 Levene of the first week to the sixth week of life nd therefter the rte is slower Rel-time ultrsound provides method for mesuring lterl ventriulr size in infnts Mesurement of the VI llows dignosis of dilted ventriles for given gesttionl ge, nd regulr ssessment of size permits erly detetion of devition in lterl ventriulr growth Use of these hrts permits both hydroephlus nd erebrl trophy to be dignosed erly in their development nd pproprite tion tken I thnk Dr M R Lebed for ssistne, Miss A Smith for seretril help, Professor Vitor Dubowitz for help nd enourgement, nd the Deprtment of Medil Art, Royl Postgrdute Medil Shool, for the illustrtions This work ws supported by the Wellome Trust Referenes 1 Grumme T, Frommel G, Meese W Post ntle ehoenephlogrphishe Untersuhungen bei Fruhgeborenen Neuropeditrie 1971; 3: Grumme T, Meese W, Frommel G hoenephlogrphishe kontrolluntersuhungen n Fruhgeborenen whrend der ersten 18 Lebensmonte Neuropeditrie 1974; 5: Grumme T Die Breite der 3 Hirnkmmer vom Fruhgeborenen bis ins 1 Dezennium Fortshr Neurol Psyhitr 1977; 45: ' Dill R hoenephlogrphishe Normlwerte des kindlihen Ventrikelsystems in den vershiedenen Altersgruppen Montsshr Kinderheilkd 1971; 119: Welthll S R, Todd J H, Bll C The role of A-sope enephlogrphy in hildhood hydroephlus Dev Med Child Neurol 1973; Supplement 29, Tenner M S, Wodrsk G, Adpon B D Newer ultrsound tehniques in the evlution of neurologi disorders Rdiol Clin N Am 1974; 12: vns W A, Jr An enephlogrphi rtio for estimting ventriulr enlrgement nd erebrl trophy Arh Neurol Psyhitr 1942; 47: Olgrd A Chnges in ventriulr size during pneumoenephlogrphy Neurordiology 1971; 3: 8-11 Nidih T P, pstein F, Lin J P, Kriheff I I, Hohwld G M vlution of peditri hydroephlus by omputed tomogrphy Rdiology 1976; 119: Hhn F J Y, Rim K Frontl ventriulr dimensions on norml omputed tomogrphy AJR 1976; 126: Wolpert S M The ventriulr size on omputed tomogrphy J Comput Ass Tomogr 1977; 1: Fukuym Y, Miyo M, Ishizu T, Mruym H Developmentl hnges in norml rnil mesurements by omputed tomogrphy Dev Med Child Neurol 1979; 21: Denkhus H, Winsberg F Ultrsoni mesurement of the fetl ventriulr system Rdiology 1979; 131: Lombroso C T, rb G, Yogo T, Logowitz N Twodimensionl ultrsonogrphy: method to study norml nd bnorml ventriles Peditris 1968; 42: Johnson M L, Mk L A, Rumk C M, Frost M, Rshbum C B-mode ehoenephlogrphy in the norml nd high risk infnt AJR 1979; 133: Hnson J, Levnder B, Liliequist B Size of the intrerebrl ventriles s mesured with omputer tomogrphy, enephlogrphy, nd ehoventriulogrphy At Rdiol [Suppl] (Stokh) 1975; 346: Ppe K, Blkwell R J, Cusik G, et l Ultrsound detetion of brin dmge in preterm infnts Lnet 1979; i: Levene M I, Wigglesworth J S, Dubowitz V Cerebrl struture nd intrventriulr hemorrhge in the neonte: rel-time ultrsound study Arh Dis Child 1981; 56: Hely M J R A men differene estimtor of stndrd devition in symmetrilly ensored norml smples Biometrik 1978; 65: Lst R J, Tompsett D H Csts of the erebrl ventriles Br J Surg 1953; 4: Gyldensted C Mesurements of the norml ventriulr system nd hemispheri suli of 1 dults with omputed tomogrphy Neurordiology 1977; 14: Johnson M L, Rumk C M Ultrsoni evlution of the neontl brin Rdiol Clin NAm 198; 18: Ztz L M The vns rtio for ventriulr size: lultion error Neurordiology 1979; 18: Willims J, Hirsh N J, Corbet A J S, Rudolph A J Postntl hed shrinkge in smll infnts Peditris 1977; 59: Cooke R W I, Rolfe P, Howt P Apprent erebrl blood-flow in newborns with respirtory disese Dev Med Child Neurol 1979; 21: Donn S M, Philip A G S rly inrese in intrrnil pressure in preterm infnts Peditris 1978; 61: 94-7 Correspondene to Dr M I Levene, Deprtment of Peditris nd Neontl Mediine, Institute of Child Helth, Hmmersmith Hospitl, Du Cne Rod, London W12 OHS Reeived 3 June 1981 Arh Dis Child: first published s 11136/d56129 on 1 Deember 1981 Downloded from on 21 July 218 by guest Proteted by opyright