Magnetic resonance imaging of the pediatric spine

Transcription

1 RdloGrphlcs Index terms: MgnetIc resonnce ImgIng Musculoskeletl Imging PedItrIc Imging Cumultive index terms: Spine; MR studies Mgnetic resonnce (MR); in infnts nd children Children; skeletl system Mgnetic resonnce imging of the peditric spine Hrold S. Wlker, M,D,* Robert B. Lufkin, M.D,* Roslind B. Dietrich, M.B.,ChB.* Wrwick J. Pecock, M.D.t Bonnie D. Flnnign, M.D. Hooshng Kngrloo, M,D.* The uthors conclude tht MRI is the imging mode of choice for the evlution of extrdurl nd intrmedullry tumors nd for the screening of ll children with suspected spinl pthology. Introduction THIS EXHIBIT WAS DISPLAYED AT THE 72ND SCIENTIFIC ASSEMBLY AND AN- NUAL MEETING OF THE RADIOLOG- ICAL SOCIETY OF NORTH AMERICA, NOVEMBER 3-DECEMBER 5, 1986, CHICAGO, ILLINOIS. IT WAS RECOM- MENDED BY THE MRI AND PEDIATRIC RADIOLOGY PANELS AND WAS AC- CEPTED FOR PUBLICATION AFTER PEER REVIEW AND REVISION ON JUNE 15, The usefulness of MRI in evluting dult spinl ntomy nd disese processes hs become incresingly evident in the lst severl yers. MRI, however, is lso prticulrly well suited for use in the peditrid popultion where ptient irrdition is of more concern, nd invsive procedures re frequently more difficult, often requiring generl nesthesi. When evluting MR imges of the peditric spine, it is impertive to hve thorough knowledge of norml ntomy, nd of chnges in the ppernce of the spine tht occur with ge. The purposes of this pper re therefore: I. to demonstrte the norml MRI ntomy of the peditric spine nd to demonstrte ge-relted chnges; 2. to show the bility of MR to imge pthologicl bnormlities of the peditric spine; nd 3. to describe techniques for opti-. ml visuliztion of lesions of the spine in children. From the UCLA Medicl Center, Deprtment of Rdiologicl Sciences( ). nd Division of Neurosurgery(t). Los Angeles. nd Vlley Presbytenn Hospitl. Deprtment of Rdiology(t), Vn Nuys, Cliforni. Address reprint requests to RB. Dietrich, M.B.,ChB, Deprtment of Rdiologicl Sciences, UCLA Medicl Center, Los Angeles. CA 924. Mterils nd Methods MR imges of the spine were obtined in 125 children nd young dults (ged 3 weeks to 21 yers, men ge = 9 yers). Of these, 36 were children with no known spinl pthology who were imged to. evlute djcent orgns. The imges of these ptients, obtined in sgittl nd trnsxil plnes were compred to cdveric sections of the spines of newborn infnts. The remining 89 ptients were imged in order to evlute suspected spinl pthology. Dignoses were confirmed by correltion with plin rdiogrphs, CT scns, sonogrms or surgicl findings. Volume 7, Number 6 #{149}November, 1987 #{149}RdioGrphics 1129

2 MRI of the peditric spine Wlker ci l. V C V C MR imging ws performed using.3 T permnent mgnet (Fonr B-3) whole body imger. Solenoid bnd or plnr surfce coils, nd bdominl compression pds were used whenever possible. Interleved short TR, short TE spin echo pulse sequences (SE 3/18 or 5/28) were obtined in ll ptients with slice thicknesses of 5 to 7 mm t intervls rnging from 7 to 1 mm. In ptients suspected of hving inflmmtory or neoplstic lesions, T2 weighted Sequences were lso obtined (SE 15/56 or 2/84). Imges were initilly obtined in the sgiffl or trnsxil plnes, depending on the pthology demonstrted. Children less thn 7 yers old were routinely sedted with chlorl hydrte, meperidine/promethzine/chlorpromzine (DPI), or rectl thiopentl. Ptients were visully monitored, nd rdiologist ws present t ll times to tilor the study. Norml Norml MRI ntomy in sgittl, trnsxil nd coronl plnes is demonstrted in Figures 1-6. The following discussion will highlight some of the mjor differences between the dult nd the peditric spine nd will illustrte chnges in the spine with ge. A trnsverse line of intermedite signl intensily cn be seen crossing the vertebrl bodies of infnts nd is prticulrly prominent in children less thn one yer of ge. This represents the horizontl crtilginous plte, the Antomy plne of junction t which the two mesenchyml sclerotomes fuse to form the vertebrl body (Figure IA). With incresing mturtion, the crtilginous re decreses in size s ossifiction progresses. The intervertebrl discs re thicker nd hve more sphericl shpe in the newborn thn they hve in the dult (Figures lb- E). With incresing ge, the intervertebrl discs become fltter nd the previously biconcve vertebrl bodies tke on more nerly squre ppernce (Figure 2). messnchyml #{149}cI.rotom. -*- int#{149}rs#{149}gmntl vissel IA notochord Figure 1 (A) As the spine develops in the embryo, the vertebrl bodies re formed by the fusion of two mesenchyml sclerotomes. The intervertebrl disc lso develops from the sclerotome. The intersegmentl vessels cross the res of fusion nd lter become the bsivertebrl veins. (Adpted from Bnn, Clinicl Rdiology of the Spine nd Spinl Cord. Aspen Systems Corportion, Rockville, MD, 1985:24) (B-E) Norml sgittl ntomy Antomic sections of the cdver with corresponding MR imges (SE 5/28): Lines of intermedite signl intensity in the biconcve vertebrl bodies (rrowheds, C&E) correspond to crtilginous pltes t the sites of fusion of the sclerotomes (closed rrows, B&D). The intervertebrl discs re thick nd rounded (open rrows, D&E). 113 RdloGrphics #{149}November, 1987 #{149}Volume 7, Number 6

3 Wlker ci l. MRI of the peditric spine z 3 C Volume 7, Number 6 #{149}November, 1987 #{149}RdioGrphics 1131

4 MRI of the peditric spine Wlker ci l. >1. E z Figure 2 Age relted chnges in ntomy (A&B) Sgittl MR imges (SE 5/28) of norml one yer old child: The intervertebrl discs (rrowheds, A&B) hve become fltter, n the vertebrl bodies re more nerly squre. The cord is in the center of the spinl cnl (closed rrow, A). (C&D) Sgittl MR imges I (SE 5/28) of three yer old child: The cord now lies more nteriorly (open rrow, C). It is closer to the vertebrl bodies in the thorcic spine thn in the lumbr or cervicl regions RdioGrphics #{149}November, 1987 #{149}Volume 7, Number 6

5 Wlker ci l. MRI of the peditric spine The spine in the infnt is strighter thn tht of the older child nd dult, with less thorcic kyphosis nd less lumbr lordosis. The spinl cord in infncy my normlly extend inferiorly to the level of L2-3, but it should hve reched its finl position, t LI-2, by Iwo months of ge (13). In the infnt, the cord is positioned in the center of the cnl, but its reltive position chnges s norml kyphosis develops (Figure 2). The centrl cnl of the cord is more prominent in the child thn in the dult nd frequently cn be identified on norml studies (Figure 5B). The cross sectionl shpe of the cord of the infnt is similr to tht of the dult, ppering ovl in the cervicl spine, round in the thorcic region, nd more nerly squre in the lumbr region (Figure 3). z 3 C Figure 3A-D 3C Norml trnsxil ntomy Trnsverse sections through norml newborn spine with corresponding trnsxil MR imges (SE 5/28): (A&B) In the cervicl region, the cord hs n ovl shpe. (C&D) The thorcic cord hs more nerly round configurtion. Volume 7, Number 6 #{149}November, 1987 #{149}RdioGrphics 1133

6 MRI of the peditric spine Wlker ci l. >1 E z 3E the lrger size of the exiting lumbr nerve roots. The nerve roots of the cud equin cn be seen lyering posteriorly (rrows) (G&H) RdioGrphics #{149}November, 1987 #{149}Volume 7, Number 6

7 Wlker ci l. MRI of The peditric spine Becuse the spine in young children is reltively stright, coronl imging cn often imge long segments of the vertebrl column, spinl cnl nd spinl cord, giving more ntomic informtion thn cn be obtined with single coronl view in n older ptient (Figure 4). If lumbr lordosis nd thorcic kyphosis hve developed, imging in nonorthogonl plne my be performed to visulize longer segments of the cord (Figure 5). z 3 C 4C Figure 4 Norml coronl ntomy Coronl MR imges (SE 5/ 28) of two yer old girl: (A-D) In this plne, structures such s the trnsverse processes (open rrow, A), conus medullris (curved rrow, B), bsivertebrl vein (short rrow, C), scending lumbr vessels (rrowheds, C&D), nd intervertebrl discs (long rrow, D) re ll well demonstrted. Volume 7, Number 6 #{149}November, 1987 #{149}RdioGrphics 1135

8 MRI of the peditric spine Wlker ci l. E z Figure 5 Norml spine of one yer old boy Scout nd nonorthogonl MR imges (SE5/28): (A) In this scout imge, the cursors re positioned prllel to the spinl cnl. (B) The 5B resulting imge demonstrtes long segment of cord (rrow). Children lso demonstrte more prominent epidurl ft thn dults, prticulrly in the region of the scrl nterior epidurl spce (Figures 6A&B). A rounded re of high signl intensity in the center of the vertebrl body, occsionlly seen on TI weighted imges, is thought to be norml vrint (Figure 6) RdioGrphics #{149}November, 1987 #{149}Volume 7, Number 6

9 Wlker ci l. MRI of the peditric spine z 3 C Figure 6 Norml vrints (A) Sgittl nd (B) trnsverse MR imges (SE 5/28) of norml five yer old boy: There is prominent epidurl ft in the nterior scrl epidurl spce (rrows,a&b). The ptient ws entirely symptomtic. (C) Sgittl MR imge (SE5/28) of norml 15 yer old girl: Polk dot spineround res of high signl intensity in the center of the vertebrl bodies: These my represent res of decresed cellulrity nd incresed ft in the vertebrl body bone mrrow. Volume 7, Number 6 #{149}November, 1987 #{149}RdioGrphics 1137

10 MRI of the peditric spine Wlker ci l. Congenitl In ptients evluted for possible spinl dysrphism, MRI ws ble to identity the presence of tethered cords (but not the durl dhesions tethering them), thickened fil, widened durl scs, distemtomyeli, lipoms, meningoceles, nd hydrosyringomyelis. On sgittl imges lone, definition of the exct level of termintion of the conus medullris ws often difficult becuse of prtil volume effects on the imges of the filum terminle nd nerve roots of the cud equin (V. In these ptients, dditionl imges in the coronl, trnsxil, or oblique plnes were often useful to define the conus tip better (Figure 7). Reducing slice thickness from 7 mm to 5 mm reduced the prtil volume effect nd lso mde the filum terminle esier to identity. Defining the termintion of the centrl cnl helped to differentite between low lying conus nd thickened filum. In ddition to imges obtined in trnsxil, coronl nd sgittl plnes, imges obtined in nonorthogonl plnes cn be extremely useful. Dysrphism Besides defining the conus better, nonorthogonl imges re helpful in elucidting complidted dysrphic conditions. In one ptient with scrl dysgenesis, oblique imges were ble to identify the course of the spinl cord s it pssed into widened durl sc (Figure 8). As reported by other uthors (4), we were unble with MRI to demonstrte durl dhesions tethering the cord. Becuse of this limittion, MRI should be considered complementry technique to myelogrphy in the evlution of suspected tethered cord. The benefit of obtining Iwo views in conventionl rdiogrphy lso pplies to MR imging. It is impertive tht imging be done in t lest two plnes t right ngles to one nother, in order to define three dimensionl ntomy. For exmple, in two ptients with distemtomyeli, imging in the sgittl plne identified the low position of the cords, but only trnsxil or coronl imges showed the split spinl cords (Figure 9). Figure Nonorthogonl imging (A) Trnsverse MR scout imge (SE 5/28): The cursor lines show the nonorthogonl plne tht ws selected to give dditionl informtion bout the level of the conus medullris. (B) The resulting oblique MR imge (SE 5/28): A normlly positioned conus medullris (rrow) nd exiting nerve roots (rrowheds) re clerly demonstrted. 7B 1138 RdioGrphics #{149}November, 1987 #{149}Volume 7, Number 6

11 Wlker ci l. MRI of the peditric spine 3 ( 3 C V B Figure 8 Tethered cord This nine yer old boy ws exmined becuse of the possibility of tethered cord. (A) Sgittl MR imge (SE 5/28): There is scrl dysgenesis nd low lying cord tethered posteriorly (rrow). Cursor lines define the plne of nonorthogonl imging. (B) The resulting oblique MR imge (SE 5/28): The spinl cord (rrow) is seen entering widened durl sc. Figure 9 Distemtomyeli This 17 yer old girl hd symptoms of tethered cord. (A) Sgittl MR imge (SE 5/28): Although the sgittl imge demonstrtes block vertebr, lipom, dilted centrl cnl nd low lying cord (rrow), only the trnsxil view revels the division of the cord (B). Volume 7, Number 6 #{149}November, 1987 #{149}RdioGrphics 1139

12 MRI of the peditric spine Wlker ci l. E C e Lipoms were esily identified by their high signl intensity in TI weighted imges. Lipoms could be differentited from prominent epidurl 1 ft, which occurs normlly in children, by their : posterior loction nd subcutneous extension. g The reltions of the lipoms to the cord nd g nerve roots re well demonstrted by MRI (Fig- C.) ure 1). When evluting cystic lesions, MRI ws ble to suggest the cystic nture of lesion on the bsis of its displying well defined mrgins nd signl intensity equl to tht of CSF. MRI ws lso ble to define the reltionship of the lesion to the cord (Figures II nd 12). Figure 1 Lipoms nd sinus trcts This 7 month old girl presented with scrl mss. (A) Coronl MR imge (SE 5/28): A high signl intensity lipom is seen displcing the cord to the left. (B) Sgittl MR imge (SE 5/28): Cutneous sinus trcts re depicted (rrows). (C) Sgittl MR imge (SE5/28): Nerve roots (rrowheds) re tethered by the surrounding lipom. 114 RdioGrphics #{149}November, 1987 #{149}Volume 7, Number 6

13 Wlker ci l. MRI of the peditric spine I..: 3 ( 3 V 3. 3 Figure 11. Cystic lesion-cervicl cord syringohydromyell This 6 yer old girl ws reported to hve Chiri II mlformtion when dmitted, nd ws ventiltor dependent. (A) Sgittl nd (B) trnsxil MR imges (SE5/28): A cystic cvity is present within the cord (open rrows) with trophy of the cord distl to this lesion. Also demonstrted is hernition of the cerebrellr tonsils (rrow,a). Figure 12. Cystic lesion-rchnoid cyst This 16 yer old girl hd lower extremity wekness nd difficulty in wlking. A myelogrm reveled n extrmedullry mss from T6 to T9. (A) Sgittl MR imge (SE 5/28) nd (B) sgittl MR imge (SE 15/So): A cystic collection, displcing the cord nteriorly (rrow, A), hs similr signl intensity to CSF on both TI nd T2 weighted imges. At surgery, this proved to be n rchnoid cyst. It ws drined nd the ptient ws symptom free postopertively. Volume 7, Number 6 #{149}November, 1987 #{149}RdioGrphics 1141

14 MRI of the peditric spine Wlker ci l. E U) C. U) >1 C ) C 13A Figure 13 Down s syndrome This 8 yer old girl hd symptoms of cord compression. (A&B) Sgittl nd trnsxil MR imges (SE 5/28): Atlntoxil subluxtion nd compression of the cord is evident (rrows). This hs been described in 12% to 2% of ptients with Down s syndrome (5). Although conventionl rdiogrphy, polytomogrphy nd CT re better suited for the evlution of bony bnormlities of the crniovertebrl junction (5,6), MRI ws superior to other types of imging for defining ssocited bnormlities of the cervicl cord (Figures 13 nd 14). Figure 14 Hurler s syndrome This 14 yer old ptient ws lso exmined becuse of symptoms of cord compression. Sgittl MR imge (SE 5/28): There is nteroposterior nrrowing of the formen mgnum with compression of the cord (rrow). The vertebrl bodies re bek shped s is typicl of this condition RdioGrphics #{149}November, 1987 #{149}Volume 7, Number 6

15 Wlker ci l. MRI of The peditric spine More severe forms of dysrphism, such s meningomyelocele, were lso imged without difficulty nd their internl ntomy defined (Figure 15). 15A Figure 15 Meningocele This 2 yer old girl hd multiple congenitl nomlies nd lumbr mss. She ws exmined to rule out ssocited spinl nomlies. (A) Sgittl nd (B) trnsxil MR imges (SE 5/28): Septtions within the sc of lrge meningocele (open rrow) were demonstrted prior to surgery. There is n ssocited tethered cord (curved rrow) with widened centrl cnl (rrowhed). Also seen is exstrophy ofthe bldder. 15B Volume 7, Number 6 #{149}November, 1987 #{149}RdioGrphics 1143

16 MRI of The peditric spine Wlker #{149}i l. Tumors MRI ws vluble in detecting tumors nd defining their extent. Primry, metsttic nd diffusely infiltrting neoplsms of the spine were imged. Tumors involving vertebrl bodies were usully seen s regions of lower signl intensity thn the surrounding tissue on TI weighted imges nd of higher signl intensity on T2 weighted imges. The importnce of using both TI nd T2 weighted imges ws illustrted by one cse of metsttic Ewing s srcom in which the presence of tumor ws indicted only by chnge in the shpe of vertebrl body on TI weighted imges. Only T2 weighted imges showed the high signl intensity of the tumor which differentited it from surrounding norml mrrow (Figure 16). This illustrtes the desirbility of obtining both TI nd T2 weighted imges in ll studies. Figure 16 Metsttic Ewing s srcom This 2 yer old mn with Ewing s srcom of the femur ws exmined becuse of bck pin. (A) Sgittl MR imge (SE 5128): Although there is n obvious bnormlity of the shpe of the involved vertebrl body, the signl intensity of the bone mrrow is similr to tht of the djcent norml vertebrl bodies. Usully, with metsttic involvement of bone mrrow, the signl intensity of the involved mrrow decreses. (B) Sgittl MR imge (SE 2/56): Only on T2 weighted imges such s this is there n increse in the signl intensity of the bone mrrow of the ffected vertebrl body, differentiting it from djcent norml vertebrl bodies RdioGrphics #{149}November, 1987 #{149}Volume 7, Number 6

17 Wlker ci l. MRI of The peditric spine Diffuse involvement of the mrrow in the row involvement my be difficult to pprecite spine ws seen in eight ptients with neurobls- (Figure 18). Although some uthors suggest tht tom nd in four with leukemi, while lym- MRI cn redily dignose leukemic infiltrtion phomtous involvement of the spine in two ptients ws noted to be ptchy (Figure 17). In diseses tht ffect the bones diffusely, bone mr- (9), our experience does not support this conclusion. -4 C 3 Figure 17 Lymphom This 8 yer old girl hd bck pin (A) Sgittl MR imge (SE5/28): The signl intensify of the ffected vertebrl body is less thn tht of the other vertebrl bodies. There is extrdurl extension posteriorly, compressing the cord (rrow). This ws proved by biopsy to be lymphom. (B) Coronl MR imge (SE 5/28): There is no evidence of lterl extension of the tumor. The preservtion of the disc spce nd the lck of soft tissue involvement bout the involved vertebr mke discitis nd osteomyelitis unlikely. Figure 18 Acute lymphoblstic leukemi This 5 yer old girl presented with fever, incresing bdominl girth nd bck pin. (A) Lterl spine rdiogrph: There is diffuse osteopeni nd flttening of the vertebrl bodies. (B) Sgittl MR imge (SE 5/28): Diffuse flttening of the vertebrl bodies is gin seen, but there is uniformity of the signl from the mrrow, nd the diffuse replcement ofthe bone mrrow by tumor is not so esily pprecited s is involvement of single vertebrl body. 18B Volume 7, Number 6 #{149}November, 1987 #{149}RdioGrphics 1145

18 MRI of The peditric spine Wlker ci l. (I) E 3 I- One cse of primry Ewing s srcom demonstrted the verstility of MRI in the dignosis nd followup of spinl tumors. As described previously, the signl intensity of the mrrow of bones included in rdition tretment port is greter thn norml (11) (Figure 19). Figure 19 Primry Ewing s srcom This 3 yer old girl ws studied becuse of bck pin ccompnied by systemic illness. (A) Sgittl MR imge (SE 5/28): Involvement of LI with posterior extension of the tumor into the spinl cnl is seen in this initil study. (B) Trnsxil MR imge (SE 5/ 28): Extension of the tumor into the cnl nd lterl displcement of the cord is evident (rrow). Biopsy proved the lesion to be Ewing s srcom. (C) Sgittl MR imge (SE5/28): After irrdition nd chemotherpy, collpse of the ffected vertebrl body nd n increse in signl intensity from the other vertebrl bodies within the rdio RdioGrphlcs #{149}November, 1987 #{149}Volume 7, Number 6

19 Wlker ci l. MRI of The peditric spine In the spinl cord, MRI redily defined intrmedullry tumors. In this group of lesions, T2 weighted pulse sequences were essentil for detecting the presence of tumor nd delineting its extent (Figure 2). -4 C 3 1 Figure 2 Intrmedullry tumor-strocytom This 21 yer old womn hd symptoms of incresed sweting bout her hed nd neck with other vgue, trnsient neurologic complints. (A) Sgittl MR imge (SE 5/28): A region of low signl intensity is seen (rrows) expnding the upper cervicl cord. (B) Sgittl MR imge (SE 2/56): A T2 weighted imge more clerly defines the extent of the mss. MRI demonstrted lrger extrmedullry lesions, such s neurofibroms very well (Figure 21), but smller lesions such s drop metstses, were likely to be missed unless they impinged on the cord or nerve roots or displced them. Myelogrphy is still clerly the procedure of choice for evluting smll extrmedullry spinl lesions (3,12). (Although the improved bility of MRI to demonstrte drop metstses fter the dministrtion of intrvenous gdolinium-dtpa my chnge this in the future.) Extrdurl nd extrspinl tumors were lso imged by MRI, nd coronl views were found to be extremely helpful for demonstrting the origins nd extents of prspinl tumors (14) (Figures 22 nd 23). Volume 7, Number 6 #{149}November, 1987 RdioGrphlcs 1147

20 MRI of The peditric spine Wlker ci l U) I Figure 21 Extrmedullry, intrdurl tumors - neurofibromtosis This 21 yer old mn ws known to hve neurofibromtosis. Sgittl MR imge (SE 5/28): An extrmedullry, intrdurl mss compressing the cervicl cord is present. This ws found t surgery to be neurofibrom RdioGrphics #{149}November, 1987 #{149}Volume 7, Number 6

21 Wlker ci l MRI of The peditric spine -4 MRI cn show bnormlities of the intervertebrl disc. Becuse it cn demonstrte erly degenertive chnges, it my prove to be n idel screening tool in young thletes prior to trining progrms (2,7,8) (Figure 24). Other Trum/Degenertion trumtic lesions such s spondylolistheses, vertebrl body frctures nd posttrumtic cystic chnges of the cord hve lso been demonstrted by MRI (1) (Figures 25-27). C 3 ( 3 3 Figure 24 Degenertive disc disese This 15 yer old gymnst complined of low bck pin. Sgittl MR imge (SE5/ 28): A degenerting disc is evidenced by loss of disc height, decresed signl intensity from the nucleus pulposus nd posterior disc bulging (rrow). Figure 25 Corner frcture This 17 yer old femle gymnst ws evluted fter flling from blnce bem, hyperflexing her spine. (A) Lterl spine rdiogrph: Slight displcement of vertebrl body corner frcture cn be seen (rrow). (B) Sgittl MR imge (SE5/28): The frcture is gin evident (curved rrow). No evidence of hemtom is seen. Volume 7, Number 6 November, 1987 #{149}RdioGrphics 1149

22 C MRI of The peditric spine Wlker ci l. C ) E 3 I- Figure 26 Cervicl vertebrl frcture This 21 yer old womn ws involved in motor vehicle ccident nd sustined neck trum. She ws reevluted severl months fter the ccident. Sgittl MR imge (SE5/28): A crush frcture of the C5 vertebrl body nd cystic degenertive chnges in the cord re seen, Figure 27 Lumbr vertebrl frcture nd spondylolisthesis This 15 yer old ptient hd history of low bck pin. Sgittl MR imge (SE 5/28): A Grde 2 spondylolisthesis is demonstrted (rrow). An undisplced corner frcture of lumbr vertebrl body is lso evident (curved rrow). Metbolic Metbolic diseses which ffect the bones of the spine cn lso be imged by MRI. Although there is limited experience with MR imging of metbolic bone disese, such entities s renl osteodystrophy, fibrous dysplsi nd hypophosphtemic rickets ll demonstrted pperonces comptible with the disese process nd the plin rdiogrphic findings (Figures 28-3). 115 RdioGrphics #{149}November, 1987 #{149} Volume 7, Number 6

23 Wlker ci l MRI of The peditric spine Figure 28 Metbolic bone disese This young mn hd known renl osteodystrophy. Sgittl MR imge (SE 5/28): Regions of endplte sclerosis demonstrte decresed signl intensity, giving reverse rugger jersey ppernce. CD Figure 29 Fibrous dysplsi This 19 yer old womn with McCune Albright syndrome nd cromegly ws scnned to evlute her pituitry glnd. Sgittl MR imge (SE 5/ 28): There is bone expnsion nd diffuse decrese of signl intensity (rrow) from the mrrow of the bones of the spine nd skull owing to replcement of mrrow by fibrous tissue. Figure 3 Hypophosphtemic rickets This 8 yer old girl ws known to hve hypophosphtemic rickets. Sgittl MR imge (SE 5/28): There is bsence of signl from the mrrow of bones becuse of replcement of mrrow by corticl bone (rrow). Volume 7, Number 6 #{149}November, 1987 #{149}RdloGrphics 1151

24 MRI of The peditric spine Wlker ci l. Conclusion MRI is ble to demonstrte norml ntomy tive evlution of dysrphism nd in the evlund ge-relted ntomic chnges of the tion of extrmedullry tumors. In ddition to visulizing the spinl cord, MRI gives informtion peditric spine, which re importnt to understnd when imging pthologicl lesions. We bout the intervertebrl discs nd vertebrl believe MRI to be the imging mode of choice bodies. MRI directly visulizes bone mrrow involvement in benign nd neoplstic bone mr- for the screening of ll children with suspected spinl pthology nd for the evlution of extrdurl nd intrmedullry tumors. Sonogrphy spine, it is essentil to use surfce coils, to emrow disese. For optiml visuliztion of the remins n extremely useful screening tool in ploy pulse sequences tht produce thin sections, children less thn 6 months old, however. MRI, in nd to imge in multiple plnes. Imges obtined our judgment, should be considered replcement for myelogrphy except in the preoper- useful to define bnormlities in non-orthogonl plnes re lso frequently better. References I. Brnes PD, Lester PD, Ymnshi WS, Prince JR. MRI in infnts nd children with spinl dysrphism. MR 1986; 147: Edelmn PR, Shoukims GM, Strk DD, et l. High-resolution surfce coil imging of lumbr disk disese. AiR 1985; 144: Goy AMO, Pinto PS, Rghvendr BN, Epstein FJ. Kricheff II. Intrmedullry spinl cord tumors: MR imging. with emphsis on ssocited cysts. Rdiology 1986; 161: , Hn JS, Benson JE. Kufmn B. Recte H. Alfidi L, Bohlmn, H. Kufmn B. Demonstrtion of distemtomyeli nd ssocited bnormlities with MR imging. AJNR 1985; #{243}:2l Hreidrsson 5, Mgrm G. Singer H. Symptomtic tlntoxil disloction in Down syndrome. Peditrics 1982; 69: Lee BCP. Deck MDF, Kneelnd JB. Chill PT. MR imging of the crniocervicl junction. AJNR 1985; 6: Mrvill KR, Lesh P. Weinreb JC, Selby DK Mooney V. Mgnetic resonnce imging of the lumbr spine with CT correltion. AJNR 1985; 6: Modic MT. Pvlicek W, Weinstein MA, et l. Mgnetic resonnce imging of intervertebrl disk disese. Rdiology 1984; 152: Moore 5G. Gooding CA, Brsch RC, et l. Bone mrrow in children with cute lymphocytic leukemi: MR relxtion times. Rdiology 1986; 16: Quencer PM, Sheldon JJ, Post MJD. et l. MRI of the chroniclly injured cervicl spinl cord. MR 1986; 147: Rmsey RG. Zchris CE. MR imging of the spine fter rdition therpy: Esily recognizble effects. AJNR 1985; 6: Scotti G. Scilf G. Colombo N. Lndoni L. MR imging of intrdurl extrmedullry tumors of the cervicl spine. J domput Assist Tomgr 1985; 9: Schpiro R. Myelogrphy. 2d ed. Chicgo Yerbook Medicl Publishers, 1984; Siegel MJ. Jmroz GA. Glzer HS. Abrmson CL. MR imging of intrspinl extension of neuroblstom. J Comput Assist Tomogr 1986; 1: Smoker WRK. Keyes WD. Dunn VD, Menezes AH. MRI versus conventionl rdiologic exmintions in the evlution of the crniovertebrl nd cervicomedullry junction. RdioGrphics 1986; 6: RdioGrphics #{149}November, 1987 #{149}Volume 7, Number 6