Is "black geode" sign a characteristic MRI finding for extracranial schwannomas?. Issue 4 (19th October 2012)

• Record Type: Journal Article
• Authors: Kato, Hiroki; Kanematsu, Masayuki; Ohno, Takatoshi; Nishimoto, Yutaka; Oshima, Koji; Hirose, Yoshinobu; Nishibori, Hironori
• Is Part Of: Journal of magnetic resonance imaging. Volume 37:Issue 4(2013)
• Page Start: 830
• Page End: 835
• Publication Date: 2012-10-19
• Subjects: Magnetic resonance imaging -- Periodicals; 616
• DOI: 10.1002/jmri.23867
• Languages: English
• ISSNs: 1053-1807

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <sec id="abs1-1" sec-type="section"> <title>Purpose:</title> <p>To evaluate whether the "black geode" sign is a characteristic magnetic resonance imaging (MRI) finding for extracranial schwannomas.</p> </sec> <sec id="abs1-2" sec-type="section"> <title>Materials and Methods:</title> <p>Forty‐three patients with pathologically confirmed extracranial schwannomas underwent preoperative gadolinium‐enhanced MRI. The black geode sign was defined as the appearance of enhanced outer and inner rings. MR images were retrospectively reviewed for size, configuration, and signal intensity of the lesions in addition to the presence of the black geode sign.</p> </sec> <sec id="abs1-3" sec-type="section"> <title>Results:</title> <p>Gadolinium‐enhanced T1‐weighted images revealed the black geode sign in seven of 43 patients (16%). The thickness of inner rings (mean 0.6 cm, range 0.3–0.8 cm) was significantly greater than that of outer rings (mean 0.2 cm, range 0.1–0.3 cm) (<italic>P</italic> < 0.01). While outer rings were circular or elliptical in shape with smooth contours, inner rings had a lobular configuration with irregular thickness and contours. The degrees of enhancement were significantly stronger with inner rings than with outer rings (<italic>P</italic> < 0.01). In histopathological correlation of five patients who underwent total excision, inner and outer rings corresponded to peridegenerative areas and fibrous capsules, respectively.</p> </sec> <sec id="abs1-4" sec-type="section"> <title>Conclusion:</title> <p>The black geode sign may be fairly specific to extracranial schwannomas on gadolinium‐enhanced MR images. J. Magn. Reson. Imaging 2013;37:830–835. © 2012 Wiley Periodicals, Inc.</p> </sec> </abstract>