Journal ofthe Kore an Radiological Society 1996 : 35(2 ) : 151-158

Cerebellar Cystic Hemangioblastoma and Cystic Astrocytoma : Differentiation on MR Imaging1

In Kyu Yu, M.D., Kee Hyun Chang, M.D., Moon Hee Han, M.D., In-One Kim, M.D., Chi Sung Song, M.D.2, Sang Hyung Lee, M .D.3, Kyung Mo Yeon, M.D.

Purpose : To determine differential points, if any, on MR imaging between cer­ ebellar cystic hemang ioblastoma and cystic astrocytoma. Materials and Methods : MR images of patients with surgically proven cerebel­ lar cystic hemangioblastomas (n=12) and cystic astrocytomas (n=14) were retrospectively reviewed with regard to the following points: size, location and signal intensity ofthe tumor; tumor margin; presence, size and location ofthe en­ hancing mural nodule; vascular signal voids, internal septations, enhancing fea­ ture of the cyst wall, secondary findings (degree of peritumoral edema and pres­ ence of hydrocephalus) and the patient’ sage. Results : The significant (p(.05) differential points were vascular signal voids, which were the most important clue, as well as the presence of an enhancing mu­ ral nodule, tumor margin, enhancing feature of the cyst wall and the patient’ s age. Ifthe patient was an adult and presented an enhancing mural nodulewith ad­ jacent vascular signal voids and smooth tumor margin, then cystic heman­ gioblastoma was suggested, while the presence of an irregular-margined thick enhancing cyst wall, mural nodule without adjacent vascular signal voids and pediatric age were suggestive of cystic astrocytoma. Conclusion : On MR imaging, there are certain significant differential points between these similar-appearing tumors and these would be useful for a more ac­ curate diagnosis.

IndexWords : 8rain neoplasms, MR

cytomas include the first two groups (1 -6). Differen­ INTRODUCTION tiation of these two cystic tumors of similar appear­ ance is important in preoperative planning. On angiog­ 80th hemangioblastoma and astrocytoma are com­ raphy, cystic hemangioblastoma can be readily differ­ mon primary cerebellar tumors and on magnetic res­ entiated from cystic astrocytoma because it shows a onance (MR) imaging, they may manifest themselves hypervascular mural nodule. However, if the mural as one of three types according to their gross mor­ nodule is small , differentiation may be difficult, not phology. The first is a unilocular cyst with an enhancing only on computed tomography (CT) , but also on angiog­ mural nodule, the second is a solid mass with either raphy (5) . necrosis or cyst formation , and the third is an entirely Detailed characterization of these tumors is better on solid mass “Cystic" hemangioblastomas and astro- MR imaging than on CT, but the capability of MR imag­ ing to differentiate between these two tumors has not been well documented except for the characteristic ser­ 1D epartm ent of Radiology, Seo ul National Uni versi ty Co ll egeo f Medici ne 'Departm ent ofR adiology, BoramaeH osp ital pentine signal voids in the mural nodule of hemangiob- 3Departmentof Neurosurg ery, Boramae Hospi tal lastoma (7 , 8) . The purpose of this study is to discover Received Apri l8, 1996 ; Accepted Jun e10 , 1996 significant differential points, if any, between these two Add ress reprintrequ estst o: In KyuY uM .D., Department ofRadi ology, Seou l National Uni versity Hospital, # 28 Yongon-Dong , Chongno-Gu , Seoul , tumors on MR imaging. 11 0.744, KoreaT el:82-2.760.251 9, Fax: 82.2.743.6385

Uπ Journal ofthe Korean Rad iologi ca l Society 1996 : 35(2 ) : 151 - 158

angioblastoma), a 1.0-T superconducting unit was used MATERIALS and METHODS while the superconducting unit was a 2.0-T with 8 patien­ ts (4 hemangioblastomas and 4 astrocytomas) ; the We reviewed MR images of 12 consecutive patients images were obtained using multiecho, multislice, with surgically proven cerebellar cystic hemangioblas­ spin-echo (SE) pulse sequences. Before contrast tomas and of 14 consecutive patients with cerebellar administration, T1-weighted (400-600/15-30/2-4, TR/TE cystic astrocytomas. We classified a tumor ascystic’ /excitations) sagittal and proton-density-weighted when its cystic component was over half its total vol­ (2000-3000/20-30/1-2) and T2-weighted (2000-3000/80- ume on MR images. In the astrocytoma group, eightca­ 100/1-2) axial images were obtained. After intravenous ses of pilocytic astrocytoma (seven cases of juvenile injection of gadopentetate dimeglumine (Magnevist @, pilocytic astrocytoma and one case of adult type pil­ Shering, Germany) , (0.07-0.1 mmol/kg body weight), ocytic astrocytoma), three cases of fibril 녀 ry astroc­ T1-weighted axial and sagittal , and sometimes coronal ytoma and three cases of anaplastic astrocytoma were images were obtained in all patients. The slice thick­ included ness/gap was 5 mm/2 mm for the 2.0-T and 1.0-T unit Patient ages with hemangioblastoma ranged from 27 and 7 mm/2 mm for the 0.5-T unit. The acquisition mat­ to 66 years (mean, 38 years) , while those with astroc­ rix was 256 X 256 with spatial resolution of 1 mm X 1 ytoma ranged from 2 to 34 years (mean , 12 years). Pat­ mm. ient ages with pilocytic astrocytoma were between 3 We retrospectively analyzed MR findings with regard and 34 years (mean , 12 years; mean of juvenile pil­ to the following points : size, location and signal inten­ ocytic astrocytoma, 9 years) ; those with fibri Ilary astroc­ sity of the tumor; tumor margin ; presence, size and 10- ytoma were between 2 to 20 years (mean , 11 years); cation of the enhancing mural nodule ; vascular signal those with anaplastic astrocytoma were between 7 to vOids , internal septations, enhancing feature ofthe cyst 33 years (mean , 15 years). The male to female ratio was wall , secondary findings (degree of peritumoral edema 9:3 in cases of hemangioblastoma and 8 : 6 in those of and presence of hydrocephalus) and the patient’s age. astrocytoma. We arbitrarily classified enhancement pattern of the In the cases of 17 patients (7 hemangioblastomas tumor into three types : Type 1 tumors included those and 10 astrocytomas), MR images were obtained on a showing enhancement of only the mural nodule without 0.5- T superconducting unit ; with one patient (hem- enhancement of the cyst wall (1 A : mural nodule:::;:2 cm ,

Table 1. Comparisons 01 Characteristics betvite.en Cystic Hemangioblatoma and Cystic Astrocytoma Hemangioblastoma Astrocytoma Parameter p-value (n =12) (n=14)

• Ag e 38 years (27-66) 12 years (12-34) 0.000 • Tumor Si ze 5.5cm (2.5-8 이 5.2cm (3.0-7.0) 0.745 • Tumor Location Hemisphere 67 % ( 8/12) 57 % ( 8/14) 0.743 Vermis 27 % ( 3/12) 36 % ( 5/14) Tonsil 9 % ( 1/12) 7%( 1/14) • Tumor Margin Smooth 100 % (12/12) 50 % ( 7/14) 0.005 Irregular 0 %( 0/12) 50 % ( 7/14) • Prese nce 01 EM N 92 % (11/12) 43 % ( 6/14) 0.011 • EMN Size 1.3 cm (0.5-3.5) 2.3 cm (1.0-4 이 0.139 • VSV 92 % (11/12) 0%( 0/14) 0.000 • EMN with VSV 91 % (10/11) 0%( 0/6) 0.000 • EMN without VSV 9 % ( 1/11) 100 % ( 6/6) 0.000 .IS 33 % ( 4/12) 57 % ( 8/14) 0.234 .IMECW 0 % ( 0/1 2) 50 % ( 7/14) 0.000 • PE + 58 % ( 7/12) 50 % ( 7/14) 0.791 ++ 42 % ( 5/12) 43 % ( 6/14) +++ 0 %( 0/12) 7 %( 1/14) • Hydrocephalus 92 % (11 /12) 93 %(13/14) 0.911 Note : Size was expressed as mean size (range) in long diameter (cm) EMN : enhancing mural nodule , VSV: vascular signal voids , IS : in te rnal septation , PE: peritumoral edema ,

IMECW ‘ irregular margined enhancing cyst wall +: no or minimal degree , + + : moderate degree , + + + : severe degree

「F 1 」 4 In Kyu Yu , etal: CerebellarCystic Hemangioblastoma and Cystic Astrocytoma

1 B : mural nodule>2 cm) ; type 2 tumors showed en­ hemangioblastoma (Fig. 1) and astrocytoma (Fig. 5) hancement of both the mural nodule and cyst wall , whil­ were slightly hyperintense relative to cerebrospinal e those, which were type 3, exhibited enhancement of fluid (CSF) on all p 비 se sequences in most patients. The only the cyst wall without a demonstrable enhancing signal intensities of solid components of both types mural nodule (3A : smooth margin, 3B : irregular mar­ were slightly hypointense, or isointense relative to gin). The degree of peritumoral edema was classified brain parenchyma on T1-weighted images, and slightly as follows : no or minimal (+), moderate (+ +), and hyperintense or hyperintense on T2-weighted images severe (+ ++). in most patients. There was no significant difference Statistics were analysed using the Mantel-Haenszel between the two groups in tumor signal intensity chi-square or Wilcoxon rank sum test to determine AII hemangioblastomas showed a smooth tumor mar­ whether there were statistically significant differences gin (Figs. 1 -4), while astrocytomas showed a smooth between the two tumor groups. margin in half of all cases (7/14) . Astrocytomas with a smooth margin were type 1 B (four juvenile pilocytic RESULTS astrocytomas, Fig. 5) , type 1A (an ad 비 t-type pilocytic astrocytoma and a fibrillary astrocytoma) and type 3A The mean age of patients with hemangioblastoma (a fibrillary astrocytoma). The remaining astrocytomas was significantly higher than that of those with astroc­ showed an irregular margin (type 3B , Fig. 6, 7). In other ytoma (p=.OOO). A comparison of MR findings and en­ words, type 3B tumors were all astocytomas. There hancement type for the two tumor groups are listed in was a significant difference in the tumor margin be­ Table 1 and 2 tween the two groups (p = .005). Both tumor groups involved the cerebellar hemi­ The enhancing mural nodule was seen in 92 % sphere, vermis (Fig. 1) and tonsil in the same order of (11/12) of hemangioblastomas (Figs. 1 -3), but in 43 % decreasing frequency. The cerebellar hemisphere (Fig­ (6/14) of astrocytomas (Fig. 5). Astrocytomas with en­ s. 2 -4) was the dominant occuring site in both groups hancing mural nodule were pilocytic astrocytomas There were no significant differences in tumor location (n=5) and one fibrillary astrocytoma (n=1l. The size of (p = .743) or size (p =.745) between the two groups the enhancing mural nodule in hemangioblastomas var­ The signal intensities of cystic components of both ied from 0.5cm to 3.5cm (mean , 1.4cm) in long diam-

a b c Fig. 1. Classical cystic hemangioblastoma (Type 1A) in a 35-year-old man a. T1-weighted (600/25) sagittal MR image shows a smooth margined hypointense, but sl ightly hyperintense to CSF , cerebellar cystic tumor with a isointense small mural nodule (arrow) abutting pial surface. Note vascular signal voids intra- and adjacent to the small mu- ral nodule (curved arrows) b. T2-weighted (2500 /120) axial MR image shows smooth margined , hyperintense cerebellar vermian tumor with a hyperintense mural nodule (arrow) and minimal peritumoral edema c. Contrast-enhanced T1-weighted (600/25) sagittal MR image shows a markedly enhancing mural nodule (arrow) with adjacent vas­ cualr signal voids (curved arrow) , but no enhancement 01 cystic wall ωm Journal ofthe Korean Radiological Society 1996 : 35(2) : 151-158 eter, but from 1.0cm to 4.0cm (mean, 2.3cm) in mangioblastoma, the sizes of the enhancing mural astrocytomas. The largest enhancing mural nodule (3.5 nodules of hemangioblastomas were less than 2 cm in cm) in hemangioblastoma was seen in von-Hippel­ diameter. The enhancing mural nodules of juvenile Li ndau disease (Fig. 2). Except for this case of he- pilocytic astrocytomas were all over 2 cm in diameter.

2 3 4 Fig. 2. Hemangioblastoma (Type 1 B) with von-Hippel-Lindau disease in a 40-year-old man. Contrast enhanced T1-weighted (500/30) sagittal MR image shows a cystic cerebellar tumor with a large, densely enhancing mural nodule (curved arrow). Note vascular signal voids adjacent to the mural nodule (white arrows) and internal septation (white arrowheads). Fig. 3. Atypical hemangioblastoma (Type 2) in a 65-year-old man. Contrast enhanced T1-weighted (500/30) sagittal MR image shows smooth margined cystic cerebellar tumor with a small enhancing mural nodule and an enhancing thin cyst wall (arrowheads). Note vascualr signal voids (white arrows) adjacent to the small mural nodule. There were no tumor cells in the enhancing cystwall on the pathology Fig. 4. Atypical hemangioblastoma (Type 3A) in a 28-year-old man. Contrast enhanced T1-weighted (600/15) coronal MR image shows a smooth margined, right cererbellar hemispheric cystic tumor with densely enhancing uneven thickened cyst wal l. There is n 。 emonstrable enhancing mural nodule, but, prominent vascular signal voids (curved arrow) adjacent to the uneven thickened enhancing cyst wall , which was a clue for hemangioblastoma, rather than astrocytoma. There were tumor cells in the enhancing cystwall on the pathology.

a b c Fig. 5. Juvenile pilocytic astrocytoma (Type 1 B) in a 12-year-old female patient. a. T1-weighted (400/20) sagittal MR image shows a smooth margined, hypointense, but slightly hyperintense to CSF , cerebellar cystic tumor with a hypointense mural nodule (arrow) b. T2-weighted (3000/100) sagittal MR image shows hyperintense cystic tumor with a slightly hyperintense mural nodule (arrow). There is no peritumoral edema C. Contrast enhanced T1-weighted (500/30) axial MR image shows well-enhancing mural nodule (arrow), but no demonstrable vascular signal voids adjacent to the enhancing mural nodule M요 In Kyu Yu. etal: CerebellarCystic Hemangioblastoma and Cystic Astrocytoma

The location of all enhancing mural nodules of both mural nodule showed vascular signal voids adjacent to tumor groups was abutting the pial surface (Fig. 1 -3, theenhancingcystwall (Fig. 4). 5). There was a significant difference in the incidence of Internal septations causing a multilocular cystic ap­ enhancing mural nodules (p =.이 1) , but no significant pearance were seen in four patients (33 %) with difference in size (p = .139) and location of the enhanc­ hemangioblastoma (Fig. 2) , and in eight patients (57 %) ing mural nodule between the two groups. with astrocytoma (Fig. 6, 7). There was no significant Vascular signal voids (Figs. 1 -4) were seen only in difference in the presence of internal septations be­ hemangioblastomas (92 %, 11/12) with a significant dif­ tween the two groups (p = .234). ference (p = .000). They were found intra- or adjacent to The presence of enhancing cyst wall was seen in the enhancing mural nodule abutting the pial surface both tumor groups: 25 % (3/12) of hemangioblastomas, and were serpentine shaped. There was a case of and 57 % (8/14) of astrocytomas; there was no signifi­ hemangioblastoma which showed no demonstrable cant difference between the two groups (p =.105). How­ vascular signal voids adjacent to the enhancing mural ever, irregular margined enhancing cyst wall (Fig. 6, 7) nodule, the smallest in our series, while a case of was seen only in astrocytoma (50 %), with a significant hemangioblastoma with no demonstrable enhancing difference (p = .000).

Table 2. Comparison of Enhancement Type between Cystic Hemangioblastoma and Cystic Astrocytoma Astrocytoma Total Enhancement Hemangioblastoma (n=14) (n=26) Type (n = 12) PA(n = 8) FA(n=3) AA(n=3) Total 1 A 8(67 %) 2(14 %) 10(38 %) 1 B 1 ( 8 %) 4 4(29 %) 5(19 %) 2 2(17 %) 2( 8 %) 3A 1 ( 8 %) 1 ( 7 %) 2( 8%) 3B 3 3 7(50 %) 7 (27 %) Note P =0.006 1 A enhancement 01 only MN(MN ";;: 2 cm in diameter) 1 B: enhancement 01 only MN(MN>2 cm in diameter) 2 : enhancement 01 both MN and CW 3 A: enhancement 01 only CW with smooth margin 3 B enhancement 01 only CW with irregular margin MN : mural nodule , CW: cyst wall , PA: pilocytic astrocytoma, FA : librillary astrocytoma , AA: anaplastic astrocytoma

6a 6b 7 Fig. 6. Juvenile pilocytic astrocytoma (Type 3B) in a 17-year-old male patient a. T1-weighted (500/30) sagittal MR image shows an irregular margined , septated , sl ightly hyperintense to CSF, cystic cerebellar tumor with isointense uneven thickened cyst wall (arrowheads) b. Contrast-enhanced T1-weighted (500/30) sagittal MR image shows septated , irregular margined thick enhancing cyst wall (arrowheads) , but no demonstrable vascular signal voids adjacent to the enhancing cyst wall Fig. 7. Fibrillary astrocytoma (Type 3B) in a 8-year-old female patien t. Contrast-enhanced .T1-weighted (500/30) sagittal MR image shows a cerebellar cystic tumor with irregular margined thick enhancing cyst wall (arrowheads) and interanl septations (arrows) , but no demonstrable vascular signal voids adjacenl 10 Ihe enhancing cysl wall ω따 Journal ofthe Korean Radiological Society 1996; 35(2) : 151 - 158

The majority of both hemangioblastomas and astroc­ of cystic portion , rel ative to CSF, on T1-weighted and ytomas showed no, minimal or moderate peritumoral proton density-weighted image and an isointense sig­ edema (Fig. 1, 5). A case with severe peritumoral ede­ nal , relative to CSF, on T2-weighted image are attrib­ ma was anaplastic astrocytoma. AII juvenile pilocytic uted to the high proteinaceous contents of the station­ astrocytomas with enhancing mural nodule showed no ary cystic fluid in both tumor groups (1 , 2 -6, 10-14, 18). or minimal peritumoral edema (Fig. 5) . Hydrocephalus In hemangioblastoma, the T1 shortening effect ofcystic was seen in the majority of both tumor groups. There contents is thought to be due to a blood product from a were no significant differences in the degree of peri­ previous hemorrhage or the presence of lipid-Iaden tumoral edema (p = .791) and incidence of hydrocepha­ stroma cells, one of the essential components of hem­ lus (p = .911) between the two groups angioblastoma (6-1 이 . Tumor margin was one of the differential p 이 nts be­ DISCUSSION tween the two tumor groups. It seems that hemangiob­ lastoma can be excluded if the tumor shows irregular Hemangioblastomas are slowly growing vascular, margin. However, more clues for the differentiation of histologically benign unencapsulated neoplasms of en­ smooth margined tumors should be considered. The dothelial origin, occuring in the cerebellum, the med­ smooth tumor margin in hemangioblastoma is thought ulla near the area postrema, the spinal cord, and rarely to be resulted from the reactive change to the expansile supratentorially. Most of these tumors occur in adult­ cystic fluid in the process of chronic minor hemorrhage hood, with a peak incidence in the fourth decade, thoug­ (8 -1 1). Most astrocytomas with smooth tumor margin h up to 20 % of cases occur in childhood (1 , 6, 1 이 were of the pilocytic type. Although hemangioblastomas may be sOlid, 60 % to 73 The association of an enhancing mural nodule with a % are visualized as sharply marginated cysts with or large cyst is more characteristic of hemangioblastoma without a mural nodule. This nodule is usually rela­ than astrocytoma (3 -8). This was the case in the pres­ tively small and abuts the pial surface (1 , 5-9). Micro­ ent series. However, 43 percent (6/14) of astrocytomas scopically, hemangioblastoma is characterized by a also showed an enhancing mural nodule. AII astroc­ fine hypervascular capillary mesh in a stroma compos­ ytomas with this nodule also had a smooth tumor mar­ ed of polygonal cells without mitotic activity. The cyst gin. In a smooth margined tumor with an enhancing fluid is thought to represent a proteinaceous, gelati­ mural nodule (type 1 tumors) , the differential p 이 ntwas nous transudate from the mural nodule, sometimes the presence or absence of serpentine vascular signal with hemorrhagic elements. The cyst wall is usually not voids intra- or adjacent to the enhancing mural nodule involved by the tumor and is usually composed of neur­ In hemangioblastoma, most nodules (1 0/11) had vascu­ oglial cells(2,6). lar signal voids intra- or adjacent to the mural nodule Cerebellar astrocytomas are the most common cys­ while in astrocytoma, the enhancing mural nodules had tic cerebellar tumor of pediatric patients, accounting no demonstrable vascular signal voids. In our series, for 38 % of cerebellar tumors in children. Approximate­ the mean diameter of the enhancing mural nodule of Iy 75 % to 85 % of cerebellar astrocytomas are hist이­ astrocytoma was not significantly greater than that of ogically of the “juvenile" pilolcytic type, offering an ex­ hemangioblastoma(p = .139). The location of the en­ cellent prognosis, while 15 to 25 % demonstrate less hancing mural nOdule, abutting the pial suface, was common fibrillary astrocytoma in histology with a poor­ known to be charateristic of cystic hemangioblastoma er prognosis. Morphologically cerebellar astrocytom­ (2 , 5 -9). In the present series, however, enhancing as take three configurations as same as those of hem­ mural nodules of astrocytomas were also located abut­ angioblastomas. Microscopically, a typical cerebellar ting the pial su rface. Location and size of the enhancing astrocytoma demonstrates a pilocytic growth pattern, mural nodule were not therefore the essential p 이 nts of abundunt Rosenthal fibers, frequent microscopic calci­ difference between the two groups. In both groups, fication , vascular endothelial hyperplasia and rare most mural nodules were markedly and homogeneous- intratumoral hemorrhage (1 , 1이 . Iy enhanced by gadolinium administration, though the As in others series, the mean age ofthe patients with mural nodu hemangioblastoma was significantly higher than that of patients with astrocytoma in our series; juvenile pil­ ocytic astrocytoma showed a peak incidence in the first decade, fibrillary and anaplastic astrocytoma had a peak incidence in the second decade, while hemangiob­ lastoma showed a peak incidence in the fourth decade (1 , 10-14). As shown in Table 1, there were no significant differ­ ences in size, location and signal intensity ofthe tumor between the two groups. A slightly hyperintense signal nor In Kyu Yu , et al : Cerebellar Cystic Hem angiobl astoma and Cystic Astrocytoma ler enhancing mural nodule. In our series, the hem­ angioblastoma, whereas the presence of irregular mar­ angioblastoma with the smallest enhancing mural nod­ gined thick enhancing cyst wall , mural nodule with no ule did not show any demonstrable vascular signal voi­ demonstrable adjacent vascular signal voids and pedi­ ds adjacent to the mural nodule, while another hem­ atric age were suggestive of cystic astrocytoma. We angioblastoma with no demonstrable enhancing mural think that these points would be useful for a more accu­ nodule showed vascular signal voids adjacent to the rate diagnosis between these two similar-appearing enhancing cyst wal l. The amounts and frequency of va­ tumors on MR imaging. scular signal voids are thought to correlate with the size of the enhancing mural nodule or solid compone­ REFERENCES nts(2, 6 -9). In a study by Kucharczyk et a l. 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m Journal ofthe Korean Radiological Society 1996 ; 35(2) : 151-158

대 한방사선의 학회 지 1996;35(2): 151-158

소뇌의 낭성 혈관모세포종과낭성 성상세포종:자기공명영상에서의 감별 1

1 서울대학교의과대학진단방사선과학교실 2 보라매병원진단방사선과 3 보라매병원신경외과

유인규 · 장기현 · 한문회 · 김인원 · 송치성 2 • 이상혈 3. 연경모

목 적 :자기공명영상에서소뇌의낭성혈관모세포종과낭성성상세포종사이에감별점이있는가를알아보고자하였다.

대상 및 방법 : 수술로 확진된 12 예의 소뇌의 낭성 혈판모세포종과 14 예의 낭성 성상세포종의 자기공명영상소견 을후향적으 로분석하였다.분석내용은종앙의위치및크기，신호강도，종양의경계，조영증강되는벽재성결절유무，벽재성결절의위치및크 기，혈관성 신호소실유무，종앙내 격막유무，조영증강되는낭벽모양，종앙에 의한이차적 변화(종앙주위 부종의 정도와수두증유

무).환자의 연렁을비교하였다. 결 과 : 가장 중요한 단서로 생각되는 혈관성 신호소실유무를 비롯해서 조영증강되는 벽재성 결절유무， 종양의 경계， 조영증

강되는 낭벽모양， 환자의 연렁에서 두종앙간 유의한차이를 보였다 (p<.05). 주위 혈관성 신호소실을 동반하는 조영증강되는 벽

재성 결절， 매끄러운 경계가 있고 성인 연 렁이 면 혈관모세포종의 가능성이 높았다. 불규칙한 경계의 두껍게 조영증강되는 낭벽， 주위 혈관성 신호소실을동반하지 않는조영증강되는 벽재성 걸절，소아연렁이면 성상세포종의 가능성이 높았다. 경 론 : 비슷하게 보이는이 두종앙사이에 자기공명영상에서 몇가지 유의한감별점이 있으며 이 감별점은보다정확한진단

에 유용하리 라사료된다.

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