45-year-old man with vertigo. 45才男性 めまい

45-year-old man with vertigo.
45才男性 めまい

解答:  Ecchordosis physaliphora   (EP)  ,  泡状外脊索腫

iPad version


You tube version


Key words: Ecchordosisphysaliphora, EP,  泡状外脊索症,  異所性 脊索の遺残

Key images:

T2WI 3D axial 3

通常のT2WI だとわかりにくい 上記の様に3DT2WI (今回は内耳道撮像目的)でないと難しい

T2WI axialT2WI 3D axi reconstruction sagi, coro ADCT1WI T2WI MPR3T1WI T2WI MPRT1WI T2WI MPR2


1)MehnertF, Beschorner, KukerW,et al.

Retroclivalecchordosisphysaliphora: MR imaging and review of the literature. AJNR. 2004, 25: 1851-1855

2)   ChiharaC, Korogi Y, Kakeda S, et al.

Ecchordosis physaliphora and its variants: proposed new classification based on high-resolution fast MR imaging employing steady-state acquisition. EurRadiol. 2013 Oct;23(10):2854-60.

3) Srinivasan A, Goyal M, KingstoneM.

Case 133:

Ecchordosis physaliphora. Radiology. 2008 May;247(2):585-8. No abstract available.

4) Golden LD, Small JE Benign notochordal lesions of the posterior clivus:      retrospective review of prevalence and imaging characteristics. J Neuroimaging.2014 May-Jun;24(3):245-9.

5) KaulS, Khan OH, Edem I, et al.

Transclivalpseudomeningocele secondary to ecchordosisphysaliphora: case report and literature review. J NeurolSurg Rep. 2013 Dec;74(2):92-5.

6)  KrishtKM, Palmer CA, Osborn AG, et al.

Giant ecchordosis physaliphora in an adolescent girl: case report. J NeurosurgPediatr. 2013 Oct;12(4):328-33. doi: 10.3171/2013.5.PEDS1395. Epub 2013 Aug 2.

7)Yamamoto T, Yano S, Hide T, et al.

A case of ecchordosis physaliphora presenting with an abducens nerve palsy: A rare symptomatic case managed with endoscopic endonasaltranssphenoidalsurgery. SurgNeurol Int. 2013;4:13.

8)AlkanO, Yildirim T, Kizilkiliç O, et al.

A case of ecchordosis physaliphora presenting with an intratumoral hemorrhage. Turk Neurosurg. 2009 Jul;19(3):293-6.

9)CiarpagliniR, Pasquini E, Mazzatenta D, et al.

Intraduralclivalchordoma and ecchordosis physaliphora: a challenging differential diagnosis: case report. Neurosurgery. 2009 Feb;64(2):E387-8; discussion E388.

10) Toda H, Kondo A, Iwasaki K.

Neuroradiologicalcharacteristics of ecchordosis physaliphora. Case report and review of the literature. J Neurosurg. 1998 Nov;89(5):830-4. Review.

55-year-old woman with vertigo. Answer 解答編

55-year-old woman with vertigo. 解答編


iPad version はこちら

You tube version はこちら

Key words: 巨大くも膜顆粒, くも膜顆粒、giant arachnoid granulation, arachnoid granulation, AG, AGs

Key comment: AGs  くも膜顆粒とは?

  • 通常1cm 未満:2-8mm、
  • 古いAJNRの論文だとCT上24%, MRI上13%で(造影MRIの静脈洞の濃染欠損域として)認められる 。平均的大きさは4-5mm
  • ほとんどが画像的に横静脈洞にみられる
  • 次に多いのが静脈洞交会(TorcularHerophili)
  • 剖検例29例も検討し類似結果を得ている 出現頻度 66%
  • 剖検では1-8mmで平均2mm
  • 性差はない
  • くも膜顆粒が存在する群は有意に年齢が高め
  • 無症状がほとんどで偶然見つかる、稀に頭痛

巨大なくも膜顆粒 って? giant AGs

  • 巨大くも膜顆粒:1cm を超えるもの
  • 19個の1cmを超えるくも膜顆粒を検討した45-75才 17人(2人が2つのAGs有す)
  • 2/17症例 頭痛あり
  • 横静脈洞:12、上矢状洞:6、静脈洞交会:1
  • CSF と同等の信号域と言われていたが・・・80%はCSFと同等ではない 何故?
  • AGsは単純にCSFの袋ではない→ ビデオを見てみてくださいね。


1) Leach JL, Jones BV,  Tomsick TA, et al. Normal appearance of arachnoid granulations on contrast-enhanced CT and MR of the brain: differentiation from dural sinus disease.

AJNR Am J Neuroradiol.1996 Sep;17(8):1523-32.

2)  Trimble CR, Harnsberger HR, Castillo M, Brant-Zawadzki M, Osborn AG.

“Giant” arachnoid granulations just like CSF?: NOT!!

AJNR Am J Neuroradiol. 2010 Oct;31(9):1724-8. doi: 10.3174/ajnr.A2157.