A Large Pontine Capillary Telangiectasia Detected by Susceptibility-weighted Imaging But Inconspicuous on Diffusionweighted Imaging
HKAK Sadana, TA Lim
Hong Kong J Radiol 2010;12:190-3
A case of symptomatic pontine capillary telangiectasia detected by susceptibility-weighted imaging is reported. The lesion was inconspicuous on diffusion-weighted imaging. To our knowledge there is only limited literature emphasising the diagnostic utility of diffusion- and susceptibility-weighted imaging in such lesions, particularly with reference to the combined appearances of susceptibility- and diffusion-weighted imaging in the same lesion. A large enhancing pontine lesion involving the acoustic pathway was found on post-contrast T1-weighted magnetic resonance images in a 62-year-old woman with progressive right-sided hearing loss. Susceptibility-weighted imaging was useful for lesion characterisation as it demonstrated evidence of slow flow in the lesion. However, the lesion was inconspicuous on diffusion-weighted imaging, despite its large size. In such lesions, the diagnostic utility of gradient recalled echo sequences is well established. Limited literature about the signal characteristics of these lesions on diffusion-weighted imaging is divergent, with descriptions of both normal and hypointense appearances. Literature about signal characteristics on susceptibility-weighted imaging is more unified for the low signal appearance of such lesions. Further studies may be necessary to establish the diagnostic utility of diffusion- and susceptibility-weighted imaging to characterise these lesions, particularly with a view to differentiating ominous entities with similar appearances on conventional magnetic resonance imaging sequences.
中文摘要
磁敏感加權成像可以診斷、卻未能於彌散加權成像顯示的大型腦橋毛細血 管擴張症病例
HKAK Sadana, TA Lim
本文報告一宗未能以彌散加權成像、卻可以磁敏感加權成像診斷的腦橋毛細血管擴張症病例。據我 們了解，探討上述兩種技術診斷方式於毛細血管擴張症的診斷功能的文獻十分有限，尤其是關於兩 者顯示相同病灶的文獻。一名62歲患有右耳進展性失聰的女病人，T1-加權磁共振成像發現造影強 化且影響聽覺傳導通路的巨大腦橋病灶。由於能顯示病灶內減緩血流，磁敏感加權成像很有效；反 之，雖然是巨大病灶，彌散加權成像顯示並不清楚。對於這些病灶，梯度回波序列的診斷已經明 確。這類病灶在彌散加權成像上的訊號特徵在文獻上意見分歧，而關於磁敏感加權成像病灶為低訊 號這點文獻的觀點則較為統一。有需要進一步研究建立以上兩種技術對此種病變的診斷功能，尤其 當常規磁共振成像上表現類似時，如何將之與預後不兆的病灶區別出來。