Intracranial Meningeal Enhancement Characterization

Transcription

1 Intrcrnil Meningel Enhncement Chrcteriztion Crcterizción del relce meníngeo intrcrnel José Luis Mer C. 1 An Mrí Grndos 2 Jun Sestián Toro 3 Dniel Ospin Delgdo 4 Andrés Felipe Borrero González 4 Key words (MeSH) Meninges Archnoid Mgnetic resonnce imging Centrl nervous system Plrs clve (DeCS) Meninges Arcnoides Imgen por resonnci mgnétic Sistem nervioso centrl Summry Ojective: To descrie the chrcteristics of intrcrnil meningel enhncement (IME) s mgnetic resonnce imging findings nd their ehvior under different ssocited conditions s descried in the scientific literture. Mterils nd methods: Descriptive cross-sectionl study with dt collected from the imges rchive etween Jnury nd Decemer of 2011, otining 89 eligile studies in which it ws determined, in the originl reding, presence of IME s positive finding. Ech study ws sujected to further review y neurordiologist of the institution for morphologicl chrcteriztion of the IME. Results: The most common cuses of IME were: metsttic disese (21.3%), infectious etiology (21.3%), history of intrcrnil surgery (20.2%) nd primry neoplsms (13.5%). Of totl CNS infections (19 cses), HIV infection ws documented in 12 ptients (70.6%). The ptient with the oldest surgicl history underwent crniotomy 17 yers efore performing the MRI included in the study, with persistnce of IME with no signs of recurrence defined y imge or clinicl mnifesttions up to The most frequent IME type ws leptomeningel (LME) (46.1%), followed y mixed (MME) (43.8%) nd pchymeningel (PME) (10.1%) enhncements. In the sugroup of LME, the most common etiologies were: infectious (31.7%), metsttic disese (19.5%) nd primry neoplsms (17.1%). This trend persisted in the sugroup of PME. In the sugroup of MME, postsurgicl etiology ws the leding cuse (35.9%), followed y metsttic disese (23.1%) nd infections etiologies (18%). Conclusion: Although prticulr pttern of meningel enhncement is not indictive of specific pthology, detiled study of its fetures cn provide informtion tht llow the proposl of dignostic groups, prticulrly in cses of neoplstic or infectious etiology, relevnt contriution in cses where the norml meningel enhncement is the only normlity in MRI. 1 Resident doctor, Deprtment of dignostic imging, Universidd ICESI. Cli, Colomi. 2 Rdiologist Fundción Vlle del Lili. Associte professor, Deprtment of dignostic imging, Universidd ICESI. Cli, Colomi. 3 Rdiologist Fundción Vlle del Lili. Cli, Colomi. 4 Medicine student, Universidd ICESI. Cli, Colomi. Resumen Ojetivo: Descriir ls crcterístics del relce meníngeo intrcrnel (RMI) como hllzgo en resonnci mgnétic y su comportmiento según ls diferentes ptologís socids descrits en l litertur científic. Mteriles y métodos: Estudio descriptivo de corte trnsversl relizdo con informción recolectd de 89 estudios, entre enero y diciemre de 2011, en los cules se encontró relce meníngeo como hllzgo positivo en l lectur originl. Cd estudio fue sometido nuev revisión por un neurorrdiólogo pr l crcterizción morfológic del relce meníngeo. Resultdos: Ls cuss más frecuentes de RMI fueron enfermedd metstásic (21,3 %), etiologí infeccios (21,3 %), ntecedente de cirugí intrcrnel (20,2 %) y neoplsis primris (13,5 %). Del totl de ls infecciones del sistem nervioso centrl (19 csos) se documentó infección por VIH en 12 pcientes (70,6 %). El pciente con ntecedente quirúrgico de myor ntigüedd fue sometido crneotomí 17 ños ntes de l tom de l resonnci mgnétic incluid en el estudio, en l cul persiste el relce unque no se hn definido signos de recidiv por imgen o por clínic hst El tipo de relce más frecuente fue el leptomeníngeo Rev. Colom. Rdiol. 2017; 28(3):

2 (46,1 %), seguido del mixto (43,8 %) y el pquimeníngeo (10,1 %). En el sugrupo de relce leptomeníngeo, ls etiologís más frecuentes fueron infeccios (31,7 %), enfermedd metstásic (19,5 %) y neoplsis primris (17,1 %), persistiendo est tendenci en el sugrupo de relce pquimeníngeo. En el sugrupo de relce mixto, l etiologí posquirúrgic fue l primer cus (35,9 %), seguid de l enfermedd metstásic (23,1 %) y ls infecciones (18 %). En los csos de etiologí infeccios se encontró un predominio del ptrón de relce leptomeníngeo, nodulr y difuso, sin relce pquimeníngeo, como único tipo de relce. Conclusión: Aunque un ptrón de relce meníngeo determindo no es indictivo de un ptologí específic, el estudio detlldo de sus crcterístics puede portr informción que permite plnter grupos dignósticos, prticulrmente en csos de etiologí neoplásic o infeccios, porte de relevnci en csos en que el relce meníngeo norml es l únic lterción evidente en un resonnci mgnétic. Introduction In neuroimging, intrvenous contrst nd the resulting informtion of the enhncement produced fter its dministrtion is fundmentl to rech the dignosis of multiple pthologies y mens of findings such s norml meningel enhncement; however, its detection is inconsistent nd its interprettion my vry depending on the experience of the rdiologist nd the technique of imge cquisition. Pthologic enhncement is the result of norml distriution of contrst medium in the intrvsculr nd extrcellulr spce (1). In generl, we descrie three loctions in which pthologicl enhncement occurs nd their respective pthophysiologicl mechnisms. Anorml intrvsculr enhncement, without disruption of the lood-rin rrier (BBB) s result of neovsculriztion, vsodiltion, or norml rteriovenous communictions tht decrese men trnsit time. Extrxil, without disruption of BBB secondry to meningioms, schwnnoms or grnulomtous diseses. Extrvsculr, y disruption of BBB nd filtrtion or lekge of the contrst medium in cses of neoplstic disese, infections, infrctions, inflmmtion with demyelintion nd trum (2). There is usully meningel enhncement; however, when the integrity of the BBB is compromised s consequence of some inflmmtory process (3), pthologicl meningel enhncement pttern of the nodulr nd continuous type cn e oserved (3). The meningel enhncement pttern cn e divided into two types, pchymeningel nd leptomeningel; the first refers to enhncement of the dur mter nd is identified in the durl reflections of the cererl sickle, the tentorium, the sickle of the cereellum nd the cvernous sinus. It is typiclly thick nd cn e liner or nodulr. The leptomeningel is due to the enhncement of the pi nd rchnoid, following the pil surfce of the rin nd covering the surchnoid spce of the grooves nd cisterns. It is recognized y gyriform or serpentine ppernce (1). The literture specifies some chrcteristics tht llow the description of the meningel enhncement pttern to guide differentil dignoses, such s the prticulr cse of nodulr enhncement nd meningel tuerculosis or srcoidosis; however, in everydy prctice, other different fetures re recognized tht could further id the prctice of imging dignosis. The visuliztion of the intrcrnil enhncement with contrst medium nd therefore the meningel enhncement in mgnetic resonnce (MRI) with the use of spin echo sequences hs trditionlly llowed n dequte chrcteriztion of the sme; however, grdient echo sequences with volumetric cquisitions llow etter sptil resolution, improving performnce to visulize norml enhncement nd smll rin lesions (4-6). As for strtegies to improve the sensitivity of intrcrnil enhncement, the 3 Tesls equipment hs llowed the cquisition of imges with etter signl-to-noise rtio, less time nd lower doses of contrst medium (2, 7-9). Justifiction Meningel enhncement hs een descried s rdiologicl sign of multiple pthologies nd, depending on its chrcteriztion nd interprettion, my led to clinicl dignosis. However, the literture is scrce nd sugroups of ptients re descried, mostly with dignosis of meningioms, post-surgicl chnges or meningel infection (1, 3, 10-13), so their usefulness s sign is limited to reduced spectrum of ptients. FVL, s reference center, serves wide vriety of ptients with multiple pthologies of the centrl nervous system (CNS), which frequently results in the sign of norml meningel enhncement. Therefore, it is importnt to know how the different ptterns of meningel enhncement with respect to the pthologies tht re treted in the institution ehve, so tht, through the judicious description nd the pproprite chrcteriztion of the meningel enhncement pttern, greter security cn e otined nd thus mke etter use of this finding in norml clinicl prctice. Ojetive To descrie the chrcteristics of intrcrnil meningel enhncement (MRI) s finding in MRI nd its ehvior ccording to the different ssocited pthologies descried in the scientific literture. Mterils nd methods Descriptive cross-sectionl study, with informtion otined in 89 eligile studies, collected etween Jnury nd Decemer 2011, in which meningel enhncement ws determined s positive finding in the originl reding. Ech study ws retested y neurordiologist with 15 yers of experience, for the morphologicl chrcteriztion of the meningel enhncement Intrcrnil Meningel Enhncement Chrcteriztion. Mer J., Grndos A., Toro J., Ospin D., Borrero A.

3 Inclusion criteri We included the studies of cererl MRI with contrst medium, mde in the 1.5 tesls equipment, in which the meningel enhncement ws recorded s finding, with the terms pchymeningel nd leptomeningel. Exclusion criteri Lck of medicl history or insufficient informtion recorded. Authoriztion of the medicl ethics committe After the uthoriztion of the Ethics Committee in Biomedicl Reserch of the institution for the study, the studies were ssigned code of identifiction, without nmes, surnmes or ny other dt tht llowed their identifiction, in order to gurntee the privcy of ptients. The min investigtor ws in chrge of the custody of the dt nd these were used solely for the purposes of this investigtion. Tking into ccount tht no humn intervention ws done in this reserch, they did not pply the Helsinki Declrtion or the Genev recommendtions given for such reserch. Bsed on Resolution 8430 of 1998, which estlishes the scientific, technicl nd dministrtive norms for reserch in Colomi, this study ws clssified s risk-free since no intervention or modifiction of iologicl, physiologicl, psychologicl or socil vriles ws required. Procedure We performed serch in the registrtion system (Centricity RIS) to document 982 rin MRIs with contrst medium in 2011; we otined 259 studies descriing meningel enhncement s n normlity, of which 89 met the inclusion criteri. Susequently, the medicl records of the ptients to whom ech study elonged were reviewed nd the informtion ws recorded in dtse suject to reservtion. In ddition, ech study ws re-exmined y neurosurgeon of the institution, review performed in DICOM formt nd in dedicted worksttion, hving ll cquired MRI sequences ville. From this review, we otined informtion for the morphologicl chrcteriztion of meningel enhncement. Sttisticl nlysis Frequency distriutions were used when the vriles were qulittive, nd summry mesures nd centrl tendency when the vriles were quntittive. Results The 89 rin MRI studies reviewed elonged to 48 men (53.9%) nd 41 women (46.1%), with ges rnging from 1 to 82 yers (men of 42.7 yers). The most frequent cuses of meningel enhncement were metsttic disese, infectious etiology, history of intrcrnil surgery nd primry neoplsms of the CNS (Tle 1). Rev. Colom. Rdiol. 2017; 28(3): Tle 1. Etiology of norml meningel enhncement Cuse of norml meningel enhncement Frequency % Metsttic disese 19 21,3 Infectious 19 21,3 Intrcrnil surgery 18 20,2 Primry neoplsm of the CNS 12 13,5 Not determined 6 6,7 Cererl ischemi 3 3,4 Grnulomtosis 3 3,4 Extension of extrcrnil neoplsi 3 3,4 Extrxil leeding 2 2,2 Mediction 2 2,2 Idiopthic 1 1,1 Primry vsculitis of the CNS 1 1,1 Totl ,0 In the cses of metsttic disese, the min primry neoplsms were rest cncer (Figure 1) in 7 ptients (36%), lung cncer in 3 (15%), leukemi in 2 (10.5%) nd non-hodgkin s lymphom in 2 (10.5%). In the 19 cses of infectious etiology, the mjority showed HIVssocited CNS infection, 12 ptients (70.6%), 7 cses of toxoplsmosis, 3 cses of cryptococcosis (Figure 2) nd 2 cses of tuerculosis (TB) were found. the prticulrity of up to 2 of these opportunistic diseses were found simultneously in 3 ptients. In the 7 HIV negtive ptients the etiology ws cteril in 3 cses, virl in 2 nd tuerculosis (Figure 3) nd toxoplsmosis in the 2 remining cses. In order to select the intrcrnil surgery group, the surgicl history ws determined s the primry cuse of enhncement; ptients with ctive infection t the time of the study or with dignosis of recurrent or residul primry neoplsi were excluded from this group. Surgeries were indicted for mlignnt neoplsm in 12 ptients (66%), enign neoplsi represented y meningioms in 3 (16%) nd non-neoplstic pthology (Figure 4) in 3 (16%). In this group, the oldest ptient with norml enhncement ws sumitted to meningiom resection 17 yers efore the MRI included in the study, with no definition of signs of relpse due to imging or clinicl signs. In the group of primry CNS neoplsms, studies were included in which the ptients were not sumitted to surgery until the MRI. The neoplsis with histopthologicl postsurgicl dignosis were 2 gliolstoms, 3 medullolstoms, 1 nplstic strocytom, 1 rhdoid tumor of the posterior foss nd 1 ependymom. Additionlly, two studies with lesions in the pontocereellr ngle were included in this group of primry neoplsms, which were not sumitted to surgicl procedure or iopsy nd showed no signs of mlignncy t clinicl follow-up. For the chrcteriztion of the meningel enhncement, the type ws determined s leptomeningel, pchymenogeneous or mixed. The morphology of the enhncement ws determined s smooth, nodulr or mixed nd extension s focl nd diffuse, defining diffuse enhncement when there is extension to two intrcrnil ntomicl regions (eg, frontl nd prietl enhncement) or contrlterl extension. Additionlly, it ws clssified s infrtentoril, suprtentoril or mixed ccording to the loction of the tentorium (Tle 2). 4711

4 Figure 1. Metstsis of infiltrting ductl rest cncer nd leptomeningel crcinomtosis. MRI with T1 informtion. ) Simple. ) With contrst medium: left temporl intrxil nodulr lesion nd smooth nd nodulr leptomeningel enhncement. Figure 2. Cryptococcosis in ptient dignosed with HIV. MRI with T1 informtion. ) Simple. ) With contrst medium: nodulr leptomeningel enhncement in the posterior foss. Figure 3. Ptient dignosed with tuerculous meningitis ssocited with HIV. MRI with T1 informtion. ) Simple. ) With contrst medium: nodulr leptomeningitis nd pchymeningel enhncement y empyem dringe crniotomy ntecedent. Figure 4. Bckground of right temporl rchnoid cyst resection. MRI ) FLAIR sequence. ) Sequence with T1 informtion with contrst medium of the vertex; diffuse smooth pchymeningel enhncement Intrcrnil Meningel Enhncement Chrcteriztion. Mer J., Grndos A., Toro J., Ospin D., Borrero A.

5 Tle 2. Imging chrcteriztion of norml meningel enhncement ccording to etiology nd numer of cses y ctegory Type Morphology Extension Loction Etiology Fi Pil* Durl** Mixed Liso Nodulr Mixed Focl Diffuse Infr- Supr+ Mixed Metstsis Infectious Intrcrnil surgery Primry neoplsm of the CNS Not determined Cererl ischemi Grnulomtosis Extrcrnil neoplsi Extrxil leeding Mediction Idiopthic Primry vsculitis of the CNS * Leptomeningel, ** Pchymeningel, -Infrtentoril, + Suprtentoril The most frequent type of enhncement ws the leptomeningel (46.1%), followed y the mixed one (43.8%) nd the pchymeningel one (10.1%). In the sugroup of leptomeningel enhncement the most frequent etiologies were infectious (31.7%), metstses (19.5%) nd primry neoplsis (17.1%), with prevlence of this tendency in the sugroup of pchymeningel enhncement. In the mixed enhncement sugroup, postopertive etiology ws the first cuse (35.9%), followed y metsttic disese (23.1%) nd infections (18%). Postopertive etiology (29%) nd metsttic disese (23.7%) were the min cuses of smooth enhncement, while infectious etiology (36.4%) ws the first cuse of nodulr enhncement, followed y metsttic disese 21.2%). In cses of infectious etiology, predominnce of the pttern of leptomeningel, nodulr nd diffuse enhncement ws found. In the 7 cses dignosed with HIV nd concomitnt toxoplsmosis, 5 presented smooth pchymeningel enhncement. In the cses of metsttic disese nd post-surgicl etiology, the tendency ws diffuse enhncement without identifying predominnt chrcteristic in cses of primry neoplsi. Ptients with cererl toxoplsmosis presented, in its mjority, leptomeningel, nodulr, diffuse nd supr nd infrtentoril locliztion. In cse of CBT, smooth nd loclized leptomeningel enhncement ws oserved; however, in the more dvnced cses (2 cses) the enhncement ws predominntly nodulr nd diffuse (Figure 3). Rev. Colom. Rdiol. 2017; 28(3): Discussion nd Conclusion The pthophysiologicl mechnisms tht explin the occurrence of norml meningel enhncement such s BBB disruption, vsodilttion nd neovsculriztion (1, 2) re chrcteristic of pthologies of inflmmtory, infectious nd tumor origin. In 55% (49, n = 89) of the cses studied, the etiology of norml meningel enhncement ws metsttic disese (21.3%), intrcrnil surgery (20.2%), nd neoplsi (13.5%), which is lso expected considering tht the institution where the study ws developed is reference center for southwestern Colomi nd offers the service of clinicl neurology, neurosurgery, oncology nd rdiotherpy. These results re in ccordnce with those otined in clinicl-rdiologicl correltion study tht included 34 ptients studied y MRI with contrst medium, in whom secondry neoplstic infiltrtion ws the first cuse (38%), followed y itrogenic etiology (30%) nd inflmmtory cuses of infectious type (20%) (14). As prticulr considertion nd ecuse the ntecedent of intrcrnil surgery is recognized cuse of pchymeningel enhncement in up to 99% of ptients undergoing surgery without history of neoplsi (1, 3, 15-17), it ws decided to determine this ntecedent s the primry cuse of enhncement. A pttern ws found in which the pchymeningel nd leptomeningel (mixed) enhncement coexist, tending to e smooth, diffuse nd of infr nd suprtentoril loction regrdless of the site of the surgery, posterior foss or not. Another notle finding ws the persistence of enhncement for more thn 17 yers, following intrcrnil 4713

6 surgery, ccording to records of persistent postopertive enhncement up to 40 yers fter the procedure (18). Primry nd secondry CNS tumors shre ltertions in BBB permeility nd ngiogenesis, s mechnism tht leds to meningel enhncement (19, 20). In the present study, none of these etiologies descried distinctive meningel enhncement pttern. It is noted tht most of the primry tumors of the study were of high grde nd rest cncer ws the leding cuse in the metsttic disese group. The infectious etiology s cuse of norml meningel enhncement is recognized nd constitutes dignostic tool for the detection of this type of pthologies (1, 11-13, 20-24). It is representtive of the numer of cses where enhncement is ssocited with HIV infection nd concomitnt opportunistic infection (12 cses). In the sugroup of 7 with dignosis of toxoplsmosis s the only opportunistic infection, pituitry-leptomeningel pttern nd nodulr lesions in 5 of the cses were oserved, finding consistent with the description of the MRI pttern with typicl contrst medium of ring or nodulr enhncement of the focl lesions (25-28). An dditionl finding ws tht in the 3 ptients dignosed with cryptococcosis the type of enhncement nd morphology ws different in ech, diffuse involvement nd supr nd infrtentoril locliztion were constnt, with nodulr morphology enhncement in the mesencephlic region nd posterior foss. An dditionl finding in the study ws the increse in cererospinl fluid (CSF) signl in the FLAIR sequence, ssocited with leptomeningel enhncement in cses of infectious etiology, finding theoreticlly ttriutle to the increse in protein concentrtion s consequence of the BBB (21, 23, 29). The uthors of this study recommend the joint visuliztion of the T1 sequence with contrst medium nd FLAIR (Figure 5) s n lterntive to the use of FLAIR with contrst medium. In the other types of infectious gents, uniform pttern or tendency of enhncement ws not recognized, ecuse the cses studied were few nd most were in dvnced clinicl stges, in which pthologies such s TB tend to present enhncement nodulr more evident. In the other etiologicl groups, the numer of ptients does not llow to descrie chrcteristics tht re useful for differentil dignosis; However, in prticulr cses, such s neurosrcoidosis, meningel involvement ws predominntly sl nd of crnil pirs, with nodulr enhncement nd supr nd infrtentoril locliztion (Figure 6), findings consistent with tht descried in different pulictions (30-34). One ctegory referred to in the study ws the meningel enhncement of drug etiology, documented in two ptients with dignosis of reversile posterior leukoencephlopthy syndrome induced y L-sprginse s tretment of cute lympholstic leukemi (35, 36), n entity lredy descried in the literture nd, in the prticulr cse of ptients in the present study, ssocited with infrtentoril smooth leptomeningel enhncement (Figure 7). Although norml meningel enhncement nd its chrcteristics do not llow dignosis to e mde on its own, postsurgicl sttus, infections, nd primry or secondry oncologic disese re estlished cuses of norml meningel enhncement; This is why it is very useful to know the pthophysiologicl mechnisms tht led to norml meningel enhncement s finding, which llows the rdiologist to propose dignostic lterntives tht re more in line with the requirements of the requesting physicin nd which, together with sufficient clinicl dt, llow for more ccurte dignosis. The detiled study of the chrcteristics of meningel enhncement in specific sugroups, such s infectious or neoplstic diseses, provides informtion tht llows more specific dignosis or the discrding of less prole pthologies, fct of specil importnce in cses in which the norml meningel enhncement is the only ovious normlity in n MRI. c d Figure 5. Bcteril meningitis secondry to spondylodiscitis. MRI ) Axil with simple T1 informtion. ) Axil with T1 informtion with contrst medium, diffuse leptomeningel enhncement. c) Axil FLAIR, increse in CSF signl intensity in res of leptomeningel enhncement. d) Sgittl T1 FS informtion (ft St) with contrst medium, L5-S1 spondylodiscitis Intrcrnil Meningel Enhncement Chrcteriztion. Mer J., Grndos A., Toro J., Ospin D., Borrero A.

7 Figure 6. Neurosrcoidosis. MRI nd ) xil nd sgittl with T1 informtion with contrst medium. Diffuse leptomeningel nd pchymenongeneous enhncement with severe involvement of crnil pirs in the Turkish sddle nd prepontine region. Figure 7. L-sprginse-induced reversile posterior leukoencephlopthy syndrome. MRI ) Axil FLAIR: Lesions with high signl of periventriculr white mtter. ) With T1 informtion with contrst medium. Intense leptomeningel enhncement infrtentoril. Referencis 1. Smirniotopoulos JG, Murphy FM, Rushing EJ, Rees JH, Schroeder JW. Ptterns of contrst enhncement in the rin nd meninges. Rdiogrphics. 2007;27: Essig M, Dinkel J, Gutiérrez JE. Use of contrst medi in neuroimging. Mgn Reson Imging Clin N Am. 2012;20(4): Kirmi O, Sheerin F, Bchir MB, Ptel N, Cnt MA. Imging of the meninges nd the extr-xil spces. YSULT. 2009;30(6): Li D, Hcke EM, Trr RW, Venktesn R, Lin W, Wielopolski P. Mgnetic resonnce imging of the rin with gdopentette dimeglumine-dtpa: comprison of T1-weighted spin-echo nd 3D grdient-echo sequences. J Mgn Reson Imging. 1996;6(3): Mugler JP, Brookemn JR. Theoreticl nlysis of gdopentette dimeglumine enhncement in T1-weighted imging of the rin: comprison of two-dimensionl spin-echo nd three-dimensionl grdient-echo sequences. J Mgn Reson Imging. 1993;3(5): Mirowitz SA. Intrcrnil lesion enhncement with gdolinium: T1-weighted spin-echo versus three-dimensionl Fourier trnsform grdient-echo MR imging. Rdiology. 1992;185(2): Noeuer-Huhmnn I-M, Pinker K, Brth M, et l. Contrst-enhnced, highresolution, susceptiility-weighted mgnetic resonnce imging of the rin. Invest Rdiol. 2006;41(3): Trttnig S, Pinker K, B-Sslmh A, Nöuer-Huhmnn IM. The optiml use of contrst gents t high field MRI. Eur Rdiol. 2006;16(6): Krutmcher C, Willinek WA, Tschmp HJ, et l. Brin tumors: full- nd hlf-dose contrst-enhnced MR imging t 3.0 T compred with 1.5 T--Initil Experience. Rdiology. 2005;237(3): Mittl RL, Dvid M. Frequency of unexplined meningel enhncement in the rin fter lumr puncture. Am J Neurordiol. 1994;15: Sze G, Antomiclly TA. Review rticle diseses fetures of the intrcrnil meninges: MR imging. Am J Roentgenol. 1993: Soletsky S, Bronen R. MR imging of the crnil meninges with emphsis on contrst enhncement nd meningel crcinomtosis. Am J Roentgenol. 1989;153: Rev. Colom. Rdiol. 2017; 28(3): Phillips ME, Ryls TJ, Kmhu SA, Yuh WT. Neoplstic vs inflmmtory meningel enhncement with Gd-DTPA. J Comput Assist Tomogr. 1990;14(4): Bermúdez S, Monslve J, Aguirre D. Relce meníngeo norml en resonnci mgnétic: correlción clínico-rdiológic en 34 pcientes. Rev Colom Rdiol. 2001;12(3): Burke JW, Podrsky AE, Brdley WG. Meninges: enign postopertive enhncement on MR imges. Rdiology. 1990;174(1): Dietemnn JL, Correi Bernrdo R, Bogorin A, et l. Norml nd norml meningel enhncement: MRI fetures. J Rdiol. 2005;86(11): Sto N, Bronen RA, Sze G, et l. Postopertive chnges in the rin: MR imging findings in ptients without neoplsms. Rdiology. 1997;204(3): Elster AD, DiPersio DA. Crnil postopertive site: ssessment with contrstenhnced MR imging. Rdiology. 1990;174(1): Fidler IJ, Yno S, Zhng R-D, Fujimki T, Bucn CD. The seed nd soil hypothesis: vsculristion nd rin metstses. Lncet Oncol. 2002;3(1): Groothuis DR. The lood-rin nd lood-tumor rriers: review of strtegies for incresing drug delivery. Neuro Oncol. 2000;2(1): Ahmd A, Azd S, Azd R. Differentition of leptomeningel nd vsculr enhncement on post-contrst FLAIR MRI sequence: Role in erly detection of infectious meningitis. J Clin Dign Res. 2015;9(1):TC Mohn S, Jin KK, Ari M, Shh GV. Imging of meningitis nd ventriculitis. Neuroimging Clin N Am. 2012;22(4): Prmr H, Sitoh Y-Y, Annd P, Chu V, Hui F. Contrst-enhnced flir imging in the evlution of infectious leptomeningel diseses. Eur J Rdiol. 2006;58(1): Sze G, Soletsky S, Bronen R, Krol G. MR imging of the crnil meninges with emphsis on contrst enhncement nd meningel crcinomtosis. AJR Am J Roentgenol. 1989;153(5): Din TS. Primry centrl nervous system lymphom versus toxoplsmosis in AIDS. Rdiology. 1991;179(3): Gottumukkl RV, Romero JM, Riscos RF, Rojs R, Glikstein RS. Imging of the rin in ptients with humn immunodeficiency virus infection. Top Mgn Reson Imging. 2014;23(5):

8 27. Post MJ, Sheldon JJ, Hensley GT, et l. Centrl nervous system disese in cquired immunodeficiency syndrome: prospective correltion using CT, MR imging, nd pthologic studies. Rdiology. 1986;158(1): Shih RY, Koeller KK. Bcteril, fungl, nd prsitic infections of the centrl nervous system: Rdiologic-pthologic correltion nd historicl perspectives. Rdiogrphics. 2015;35(4): Kstrup O, Wnke I, Mschke M. Neuroimging of infections of the centrl nervous system. Semin Neurol. 2008;28(4): Smith JK, Mtheus MG, Cstillo M. Imging mnifesttions of neurosrcoidosis. AJR Am J Roentgenol. 2004;182(2): Fels C, Riegel A, Jvheripour-Otto K, Oenuer S. Neurosrcoidosis: findings in MRI. Clin Imging. 2004;28(3): Gint DT, Dhillon G, Almst J. Mgnetic resonnce imging of neurosrcoidosis. J Clin Imging Sci. 2011;1: Nowk DA, Widenk DC. Neurosrcoidosis: review of its intrcrnil mnifesttion. J Neurol. 2001;248(5): Bthl G, Singh AK, Policeni B, Agrwl A, Cse B. Imging of neurosrcoidosis: common, uncommon, nd rre. Clin Rdiol. 2016;71(1): Rthi B, Azd RK, Vsudh N, Hissri P, Swlni V, Gupt RK. L-sprginseinduced reversile posterior leukoencephlopthy syndrome in child with cute lympholstic leukemi. Peditr Neurosurg. 2002;37(4): Hourni R, Aoud M, Hourni M, Khlifeh H, Muwkkit S. L-Asprginseinduced posterior reversile encephlopthy syndrome during cute lympholstic leukemi tretment in children. Neuropeditrics. 2008;39(1): Correspondence José Luis Mer C. Universidd ICESI Clle 18 # Cli, Colomi jolumeco@hotmil.com Received for evlution: Ferury 10, 2017 Accepted for puliction: July 26, Intrcrnil Meningel Enhncement Chrcteriztion. Mer J., Grndos A., Toro J., Ospin D., Borrero A.