Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_6022_Библиотеки_им_академика_М_И_Перельмана
.pdf
FIGURE6.69MultiplecaudaequinaschwannomasinNF-2inan18year-old-woman. Sagittal postgadolinium T1-weighted MR image
showsmultiplenodularenhancingmassesadherenttothecauda.
NF,neurofibromas.
Source:FromLeeRR.Spinaltumors.In:LeeRR,ed.SpinalImaging(Spine:StateoftheArt
Reviews,Vol.9).Philadelphia,PA:Hanley&Belfus;1995;261–286.
FIGURE6.70 Multiple large sacral neurofibromas in NF-1 in an 8year-old boy. Axial T2-weighted image shows multiple large bright
neurofibromas involving all the sacral nerve roots within the nerve
rootcanalsandextendingoutalongthesacralalaintothepelvis.Note
thetypicalcentralcoreofdarkersignalinthetumors.
NF,neurofibromas.
Source:FromLeeRR.Spinaltumors.In:LeeRR,ed.SpinalImaging(Spine:StateoftheArt
Reviews,Vol.9).Philadelphia,PA:Hanley&Belfus;1995;261–286.
Meningioma
Theseoccurinmiddle-agedandolderadults,atafemale-to-maleratioofgreater
than 4 to 1. Eighty percent are located in the thoracic region (Figure 6.71).
About 6% are intradural-extradural, and an equivalent number are completely
extradural (95). These have similar signal characteristics to schwannomas,
enhance brightly and homogeneously (100), and characteristically are dural
based.Rarely,ameningiomamayhaveanintramedullarycomponent.
Paraganglioma
Spinal paragangliomas have the same histology as their more familiar
counterparts elsewhere in the body, such as the adrenal medulla and carotid
body, and have similar imaging characteristics, including prominent contrast
enhancement.They arefound inadultsand aregenerally attachedto thefilum
terminaleorcaudaequina(109)(Figure6.72).
EmbryonalTumors
Developmentaltumors(e.g.,epidermoids,lipomas,dermoids,teratomas)havea
variable appearance on MRI, depending on the constituent components
composing the tumor. Fat-saturation techniques in MRI are very helpful in
makingthediagnosisoffattycomponents(Figure6.73).Thepresenceoffat is
also definitively diagnosed by CT (by fat’s very low attenuation of
approximately100Hounsfieldunits).
Inthespine,asinthebrain,epidermoidsmaybedifficulttodetectonMRI
because they may beisointense to CSF on all standard pulse sequences(111)
(Figure 6.74). However, DWI has proven very useful in distinguishing
epidermoids (which usually demonstrate markedly restricted diffusion) from
normalCSForarachnoidcysts(whichdonot)(37,43)(seeFigure6.9).
FIGURE 6.71 Meningioma in a 62-year-old woman who presented
with a several-month history of decreasing ability to walk.
PostgadoliniumsagittalT1MRimageshowsuniformenhancementof
the well-circumscribed intradural-extramedullary mass, which
markedlycompressesthethoracicspinalcordattheT2level.Notethe
characteristicenhancing“duraltail”(arrow).
Source:FromLeeRR.Spinaltumors.In:LeeRR,ed.SpinalImaging(Spine:StateoftheArt
Reviews,Vol.9).Philadelphia,PA:Hanley&Belfus;1995;261–286.
FIGURE 6.72 Paraganglioma in a 47-year-old man. Sagittal
postgadoliniumT1MRimage showsawell-circumscribedenhancing
massadherenttothefilumterminaleattheL3level.
Source:CourtesyofDr.P.Burger;LeeRR. Spinal tumors. In: LeeRR, ed. Spinal Imaging
(Spine:StateoftheArtReviews,Vol.9).Philadelphia,PA:Hanley&Belfus;1995;261–286.
Abnormalities of spinal development, such as meningomyeloceles or
tetheredcord,arecommonlyaccompaniedbydevelopmentaltumors,especially
lipomas(Figure6.75).
Metastases
Spinal subarachnoid metastases result from CSF seeding from intracranial
primarytumorssuchasmedulloblastoma(Figure6.76)orependymoma,lungor
breastcancer(Figure6.77),orlymphoma.Thesemetastasesareoftenisointense
orslightlyhyperintenseonT1,andsomewhathyperintenseonT2,althoughthis
may be masked by T2-bright CSF. Gadolinium enhancement is extremely
helpfulinincreasingtheconspicuityofthese intradural-extramedullarylesions,
whichenhancebrightly(100).
IntramedullaryTumors
Glioma
These are the most common type of intramedullary tumor, particularly
ependymomas (especially at the conus and filum terminale) in adults and
astrocytomas in children. Sixty percent of primary cord tumors are
ependymomas (109). These expand the cord and are slightly dark on T1 and
brightonT2.Associatedcystsorsyrinxmaybeseeneithercaudalorrostralto
ependymomas, which generally enhance with contrast. Hemorrhage is not
uncommonlyassociatedwithependymomas,afactstressedbyNemotoetal.in
theirstudyofcervicalependymomas(112).Theymayalsocontaincalcification.
(GRET2*sequence maybe helpfulindemonstratinghemosiderin,which may
bemissedonFSEimaging.)
Themyxopapillarysubtypeofependymomawarrantsspecialmention(109).
These are well defined and almost exclusively found at the conus or filum
terminale(Figure6.78).They maybecomeverylarge,filling,andoccasionally
expanding the lower thecal sac with enhancing soft tissue. As mentioned, the
intramedullary ependymoma tumor is classically associated with NF-2 (107)
(Figure6.79).
Astrocytomasusuallyshowafusiformexpansionofthecordassociatedwith
T2 prolongation and (variable) enhancement (105) (Figures 6.80 and 6.81).
Cystsmaybepresenteitherintrinsictothetumororattheedgeofthetumor.
Spinalcordoligodendrogliomasare rare comprising only 0.8% to 4.7% of
intramedullarytumorsofthespinalcordandfilum(113).Theyarefoundinthe
cervicothoracicspineusuallyinpatientsintheirfourthdecadeoflife.Oneofthe
fewpublishedexamples(113)hasanappearancesimilartooursurgicallyproven
case (Figure 6.82): an enhancing intramedullary expansile mass in the
cervicothoracic cord with adjacent cystic intramedullary component. Spinal
oligodendrogliomas are often associated with meningeal or intracranial
oligodendrogliomatosis(113,114).
Hemangioblastoma
Thesetumorsmayoccursporadicallybutareoftenmultipleandassociatedwith
thecerebellarhemangioblastomas of von Hippel–Lindau syndrome. They may
exhibitthe typical cyst withassociatedmural nodule, which enhancesbrightly
withgadolinium(Figure 6.83). There may beassociated edema and, asin the
brain,theymayhaveassociatedprominentvascularity(109).
EmbryonalTumor
These were previously discussed in the Section on Intradural-Extramedullary
Tumors,butthey mayalso occurinan intramedullarylocation. Asmentioned,
they may be associated with spinal dysraphism, especially lipomas. Dermoids
andepidermoidshavevariablesignalintensitydependingontheircomposition.
Cysticteratomasmaybefoundinsidethecordsubstance(Figure6.84).
Metastases
Rarely,thesepresentasintramedullarylesionswithaprimarysiteinthebrainor
outsidetheCNS.SignalintensityislowonT1andbrightonT2;theseusually
enhancewithintravenouscontrast(Figure6.85).
FIGURE 6.73 Intradural-extramedullary lipoma in a 20-year-old
woman. (A) Left. Sagittal T1 MR image shows a very large, wellcircumscribed intradural-extramedullary T1-bright mass posterior to
and compressing the upper thoracic cord. (A) Right. Fat-saturated
postgadolinium T1 image shows complete suppression of the T1brightsignal,provingthepresenceoffatratherthanT1-brightblood.
A subtlethinrimofenhancementisnoted aroundthetumorcapsule.
(B)AxialT1imageshowsthelipomafillingandexpandingthethecal
sacandspinalcanal,markedlyflatteningthecord(arrow).
Source:FromLeeRR.Spinaltumors.In:LeeRR,ed.SpinalImaging(Spine:StateoftheArt
Reviews,Vol.9).Philadelphia,PA:Hanley&Belfus;1995;261–286.
FIGURE 6.74 Epidermoid in a 5-year-old boy. (A) Consecutive
sagittalT1-imagesshowaverysubtle(almostundetectable)intradural
bipartitemass(smallarrows)belowtheconusatthelevelsofL3–L4.
Thislesiondemonstratednoenhancementwithgadolinium.(B)(Left)
Sagittalproton-densityand(right)SagittalT2-weightedimagesagain
show the very subtle mass which is almostisointenseto CSF on all
sequences,butisbest seenon theproton-density images.At surgery,
this mass was yellow-white in color. On being cut, it had the
consistencyandflake-liketextureofabarofsoap.
CSF,cerebrospinalfluid.
Source:FromLeeRR.Spinaltumors.In:LeeRR,ed.SpinalImaging(Spine:StateoftheArt
Reviews,Vol.9).Philadelphia,PA:Hanley&Belfus;1995;261–286.
FIGURE6.75Tetheredcordwithconuslipomyelomeningoceleinan
8-year-old girl. (A) Sagittal T1 image shows a tethered cord with
conus(whitearrow)attheL3–L4levelwithposteriorlyadherentT1brightintradurallipoma.Theposteriordura(smallblackarrow)iswell
visualized outlined by fat. Note the absence of normal posterior
elements at this level and the wide spina bifida defect (large black
arrow). (B) Axial T1-image shows the C-shaped T1-bright lipoma
wrapped around the right side of the conus. Note also the epidural
lipoma posterior to the thecal sac and the abnormal bony posterior
elements.
Source:FromLeeRR.Spinaltumors.In:LeeRR,ed.SpinalImaging(Spine:StateoftheArt
Reviews,Vol.9).Philadelphia,PA:Hanley&Belfus;1995;261–286.
FIGURE6.76Intrathecaldropmetastasesfrommedulloblastomaina
3-year-oldboy.Left.T2-weightedimageshowsexpansionandedema
of the cervical cord extending up to the medulla. Note that CSF
occupies much of the midline posterior cranial fossa because some
cerebellumhasbeenresectedduetoinvolvementbymedulloblastoma.
Right. Postgadolinium sagittal T1 image shows multiple enhancing
subarachnoidmetastasescoatingtheposterioraspectofthecord,with
somelargerdepositsappearingtoextendintothecord,thusaccounting
fortheedema.
Source:FromLeeRR.Spinaltumors.In:LeeRR,ed.SpinalImaging(Spine:StateoftheArt
Reviews,Vol.9).Philadelphia,PA:Hanley&Belfus;1995;261–286.
FIGURE6.77 Intrathecal metastases from lung cancer in a 25-yearold woman. Consecutive sagittal postgadolinium T1weightedimages
showtwo smallenhancing tumornodulesat theconus. Thereisalso
diffusesubtle enhancingtumorcoating the posterior spinal cord and
cauda equina. Precontrast images showed no involvement of the
vertebralbodymarrowatanylevel.
CSF,cerebrospinalfluid.
Source:FromLeeRR.Spinaltumors.In:LeeRR,ed.SpinalImaging(Spine:StateoftheArt
Reviews,Vol.9).Philadelphia,PA:Hanley&Belfus;1995;261–286.
Соседние файлы в папке Библиотека им академика М.И. Перельмана