J Korean Radiol Soc 1998; 39 : 1063-1068

MR Imaging ofthe Meckel' s Cave : Anatomy and Pathologyl

Ho Kyu Lee, M.D. , Chang Jin Kim, M.D. 2, Soo Mee Lim, M.D. , Dae Hong Kim , M.D.

Choong Gon Choi, M.D. , Dae Chul Suh, M.D.

The Meckel ’ s cave is a dural recess containing trigeminal nerve and ganglion,

extending from the posterior fossa into the middle cranial fossa. Using MRI, internal architecture in the Meckel’s cave can be discernible, even a small nodule within it can be detected. There are a wide spectrum of disease process occurring in and or in the vicinity ofthe Meckel ’s cave. Disease can be classified into pathol­ogy of the trigeminal nerve proper, within the trigeminal cistern and outside the trigeminmal cistern. These classification depending on the location will aid in in terpretation of pathology of Meckel ’ s cave. We will demonstrate the MR anatomy and various pathologies ofthe Meckel’s cave.

Index words : Brain neoplasms, MR

Meckel’ s cave is a dural recess containing the tri­geminal nerve and ganglion, and extending from the posterior fossa into the middle cranial fossa(I - 5). On conventional MR images , the cave appears as a space filled only with cerebrospinal fluid. Using a high resol­ution MRL the internal architecture of Meckel' s cave can be discerned, and even a small nodule within it can thus be detected. A wide spectrum of disease processes occurrs in and/or in the vicinity of the Meckel ’ S cave,

and these can be classified as pathology either of the trigeminal nerve origin, or arising within or outside the trigeminal cistern. This classification based on the 10-cation helps interprete pathology of Meckel' s cave.

Normal anatomy(Figs. 1 & 2)

The main contents of Meckel' s cave are the trigem­inal (Gasserian) ganglion, and the subarachnoid space (trigeminal cistern) and its covering. The trigeminal nerve exits from the upper pons and enters Meckel’s cave through the trigeminal porus(l) . It separates into

lDepartment of Diagnostic Radiology, Asan Medical Center, Universityof Ulsan College of Medi cine SeouL Korea 'Department of Neurosurgery , Asan Medical Center University ofUlsan College of Medicine Seou!' Korea Received June 17, 1998; Accepted September 1, 1998 Address reprint requests to ‘ Ho Kyu Lee, M.D., Department ofDiagnostic Radi­ology, Asan Medical Center, University of Ulsan College of Medicine, ~ 388-1 Pungnap-dong, Songpa-ku, Seoul138-736, Korea Tel. 82-2-224-437 1 Fax .82-2-476-4719 e-mail: hklee2@www.amc.seou l.kr

multiple nerve root bundles, which gather to form the trigeminal ganglion, located anteriorly in Meckel ’s cave branching into three divisions. The ophthalmic division (Vl) courses anteriorly through the superior orbital fissure. The maxillary division (V2) proceeds anteriorly through the foramen rotundum, where it enters the superior aspect ofthe pterygopalatine fossa,

and the mandibu비la값r d비1V1씨1S잉ion (V3기) proceeds inferior야rly r t야thπrou뺑 t야따heforαra때me얹n ovale(3, 쇠

The dural relationship of Meckel ’ s cave is compli­cated. It represents an evagination of the dura of the posterior fossa under that of the middle cranial fossa ,

Trigeminal ganglion Dura mater Trigeminal cistern

ridge

Fig. 1. Sagittal section through the trigeminal ganglion. Double layered dura covers upper wall ofthe Meckel’s cave . The drawing on the left indicates the level of the section

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with a potential cleavage plane laterally between the

two fused layers. The dural-arachnoid pouch behind

the ganglion forms the trigeminal cistern, which

communicates with the infratentorial basal cistern via

the trigeminal por뼈 1)

Normal MR anatomY(Figs. 3 - 5)

To demonstrate the details of Meckel' s cave and tri­

geminal ganglion, it is important to use high resolution

T2 weighted imaging (matrix size= 196 - 256 X 512) in

the coronal plane with slice thickness of 2 - 3 mm(3, 5)

Recently , a newly developed sequence, 3D-CISS(three­

dimensional constructive interference in stead- y-state)

Ho Kyu Lee, et al : MR Imaging of the Meckel ’s Cave

Superior 。rbital

fissure Foramen rotundum

Motor root

Fig. 2. Drawing ofthe intracranial segments ofthe trigeminal nerve. Trigeminal ganglion is divided into three divisions; ophthalmic(Vl), max il!ary(V2), and mandibular (V3) div­lS lOns.

A B C

Fig. 3. Coronal T2 weighted image from the posterior to the anterior.

A. image through the trigeminal porus, B. iamge th rough the foramen spinosum(long arrow), and C. image thro ugh the for­amen ovale(short arrow). Note various pattern of trigeminal nerve bundles(small triangle). Thin band oflow signal intensity (white arrows) delineates perimeter ofthe Mecke!' s cave(T=trigeminal ganglion)

4 5 Fig. 4. Axial slice image of 3D-CISS through the inferior cavernous sinuses. Trigeminal nerve extends across the medial pet­rous ridge(arrow heads) . Nerve fibers enter the Mecke!' s cave and separate into multiple nerve bundles generating a ‘'feath­ered appearance" (open arrows) as they merge with CSF in the trigeminal cistern Fig. S. Sagittal T2 weighted image through the trigeminal nerve. Nerve root bundles extending into the Meckel ’ s cave through the petrous ridge(open arrow head) , separate and form trigeminal ganglion( white arrow head) in the anterior and lower part.

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J Korean Radiol Soc 1998; 39 : 1063-1068

originally developed for imaging the inner ear (6), has adequately depicted details of Meckel' s cave. Ad­ditionally, Tl -weighted imaging after the injection of a paramagnetic agent is important for characteriz-ation and localization oflesions.

CSF is the dominant determinant of MR signal within Meckel ’s cave (2). In the coronal plane, nerve root bundles are represented by small caliber, low sig­nal-intensity foci captured in cross section. In the axial plane, the trigeminal nerve takes on a “feathered ap­pearance" in the trigeminal cistern. In the sagittal plane, the trigeminal cistern is communicates with the CSF space of the infratentorial fossa. The trigeminal ganglion is seen as a lower-lying small solid tissue in the ventral aspect of Meckel ’s cave(3 , 4).

Pathology

Kapila et al (1) classified tumors that involve the tri geminal nerve and Meckel' s cave as intrinsic or extrinsic lesions. Including the whole pathology of Meckel ’s cave, we classified lesions as belonging to one ofthe following three groups: pathology ofthe trigem­inal nerve proper, pathology within the trigeminaI cis­tern or pathology outside the cistern. During the past five years, a totaI of 41 Iesions were detected on MR imaging of our institution(Table 1). Among these, the most common were meningioma and neurilemmoma. With regard to the trigeminaI nerve proper(Figs. 6 - 8), the most common Iesion is trigeminal neurilemmoma. These usually obliterate or dilate CSF contained in the cave. Within the trigeminal cistern(Fig. 9 - 11), the most common lesion is CSF seeding, which produces a

filling defect in the cave. For pathology ouside the cis­tern(Figs. 12 - 19), a wide spectrum of disease such as meningioma or pituitary adenoma invades and/or indents Meckel' s cave from outer sites.

A lesion from each group can therefore produce a different-shaped Meckel' s cave or indent it intrinsi­caIIy or extrinsically. Localization of compression sites of the Meckel’ s cave might be useful for evaluating the origin of extrinsic tumors.

Table 1. Various Pathologies ofthe Meckel's Cave(n=4 l}

Pathology ofthe trigeminal nerve proper Neurilemmoma Meningioma Perineural spread

Pathology within the trigeminal cistern CSF seeding Encephalocele Arachnoid cyst Tuberculous meningitis

Pathology outer the trigeminal cistern Meningioma Pituitary adenoma Skull base metastasis Thrombosis ofthe cavernous sinus Clival chordoma Secondary lymphoma Neurilemmoma ofthe abducens nerve Idiopathic hypertrophic pachymeningitis Inflammatory fibrosing pseudotumor Dural arteriovenous fistula Infratem poral hemangio pericytoma

m 6

2

2

6

3

l

건 7

5

3

2

2

6A 68 7

Fig. 6. Neurilemmoma ofthe trigeminal ganglion. A. contrast enhanced coronal Tl weighted image and (8) axial T2 weighted image. The tumor enlarges Meckel' s cave (white arrow heads) with cystic change. Intratumoral hemorrhage is associated(arrow). Fig. 7. Neurofibromatosis type II. In coronal T2 wieghted image, several small nodules (arrow heads) detected in both the Meckel’s caves are presumed as trigeminal neurilemmomas.

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Ho Kyu Lee. et al : MR Imaging of the Meckel’s Cave

8A 8B 9

Fig. 8. Nasopharyngeal squamous cell carcinoma extending into the cranial cavity. A. contrast enhanced Tl weighted image shows direct tumor extension through the foramen lacerum(arrow). Note the swell­ing ofthe cavernous sinus with an encasement ofthe internal carotid artery(open triangle) B. Perineural extension occurs along the left trigmeinal nerve (arrow heads) on contrast enhanced Tl weighted image Fig. 9. Arachnoid cyst in the Meckel ’ s cave. Coronal T2 weighted image shows far-anterior bulging ofthe f1 uid filled MeckeJ' s cave on the left(arrow heads).

A B

11 12

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Fig. 10. Transalar sphenoidal en­cephalocele A. Coronal Tl weighted image shows encephalomeningocele into infrat emporoal fossa through the large for­amen ovale. Note a large Meckel ’s cave (arrow heads) connecting to the encephalomeningocele into the infrat­emporal fossa. B. Parasagittal Tl weighted image shows downward herniation of the temporal lobe with temporal horn through the bony defects(arrow head­s)

Fig. 11. CSF seeding into both MeckeJ' s caves. Primary lesion was proved as a squamous cell carcinoma of the lung cancer. A nodular en­

‘ . 1 hancement (arrow heads) is detected in the sides ofthe Meckel’s caves after contrast JnJect lOn. Fig. 12. Sixth nerve sheath meningi oma. Upper part of Meckel ’s cave is indented by a meningioma (arrow heads)

J Korean Radiol Soc 1998; 39 : 1063-1 068

13 14

lS 16

Fig. 13. Direct carotico-cavernous fis­tula. Dilated veins indent the Meckel’s cave on the top(arrow head­s). Fig. 14. Secondary lymphoma involv ing bilateral cavernous sinuses (arrow heads) and pituitary gland indents the upper part of the left Meckel' s cave(open arrow) . Perineural spread occurs along the mandibular division ofthe trigeminal nerve.

17 Fig. 1 S. Nasopharyngeal squamous cell carcinoma. It invades the skull base producing elevation ofthe bottom ofthe Mecke!' s cave(arrow heads). Note widening of the foramen ovale (open arrows) with a associated dural tail(black arrows). Fig. 16. Presumed inflammatory granuloma in the Meckel’s cave. A platelike enhancing nodule indents the bottom of the Meckel’ s cave(arrow heads). Fig. 17. Petroclival meningioma. contrast enhanced Tl weighted image shows a skull base tumor with displacement and encasement ofthe internal carotid artery(open arrow) . It indents medial and upper aspects of Meckel' s cave(arrow heads)

A B

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i Fig. 18. Hemangiopericytoma in the mastlcator space. A. This large tumor extend into the cranial cavity through the bony de­fect of the floor of the middle cranial fossa(arrows). lntracranial portion indents the lateral aspect of the Meckel’ s cave(arrow heads). B. Contrast enhanced Tl weighted image shows a highly enhancing solid tumor producing compression of lat­eral aspect of the Meckel’ s cave (arrow heads) and the lateral displace­ment ofthe temporomandibular joint.

A B

Neurilemmoma and meningioma frequently involve

Meckel' s cave, and it is not easy to differentiate one

from the other. The localization of each lesion is helpful

for its evaluation.

In conclusion, an understanding ofthe MR anatomy

of Meckel ’s cave and categorization of its pathology is

useful for the evaluation of associated pathologies.

References

1. Kapila A, Chakeres DW , Blanco E. The Meckel ’ 5 cave: comput­ed tomographic study. Part I : normal anatomy; Part II: path이­

ogy. Radiology 1984; 152 ‘ 425-433

Ho Kyu Lee. et al : MR Imaging of the Meckel’s Cave

Fig. 19. Idiopathic hypertrophic pachymeningitis A. Contrast enhanced Tl weighted image shows diffuse thickening ofthe dura of cavernous sinuses , falx cer­ebri, and convexity dura(arrows). It makes Meckel’ s cave contract(black arrow heads) B. The thickened dura of both cav­ernous sinuses shows different stages of pachymeningitis. The dark signal intensity (white arrow heads) sugges­ts fibrotic change and the high signal intensity outer it (white arrows) means active change of the pac­hymeningitis.

2. Yuh WTC, Wright DC, Barloon TJ, Schultz DH. Sato Y, Cervan­tes CA. MR imaging of primary tumors of trigeminal nerve and Meckel's cave. AJR 1988; 151 :577-582

3. Rubinstein D, Stears RLG , Stears Jc. Trigeminal nerve and gan­gIion in the Meckel cave: appearance at CT and MR imaging. Radiolog)’ 1994; 193: 155-159

4. Daniels DL, Pech P, Pojunas KW, Kilgore DP, Williams AL, Haughton VM ‘ Trigeminal nerve anatomic corrleation with MR imaging. Radiology 1986; 159: 577-583

5. Kelly WM. Functional anatomy and cranial neuropathy Neuroimag Clin N Am 1993; 3 : 1-45

6. Casselman JW, Kuhweide R, Deimling M, et al. 3D FT MR imaging of the inner ear and cerebellopontine angle. AJNR

1993; 14: 47-57

[H한방시선의학회지 1998; 39: 1063-1068

Meckel씨 굴의 MR영상소견 : 정상해부학과 병리 1

l 울산대 학교 의과대학 진단방사선과학교실 2울산대학교 의과대학 신경외과학교설

이호규 · 검창전2. 임수미 - 김대홍 · 최충곤 · 서대철

Meckel씨굴은 중뇌와에 위치하고 삼차신경， 신경절， 및 뇌척수액으로 구성되어 있고 두겹의 뇌수막으로 둘러

싸인 경막함요이다. 이 부위에는 이러한 여러가지 구성성분으로 인하여 다양한 질환이 발생할 수 있다. 본 화

보에서는 고해상 MR을 이용한 Meckel씨 굴의 해부학적인 검토 및 이 부위에셔 발생하는 질환을 삼차신경절

명변，삼차뇌조및 삼차뇌조외부병변으로나누어 알아보았다.

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