Kim J K, Kucharczyk W, Henkelman R M
Department of Medical Biophysics, University of Toronto, Ontario, Canada.
Radiology. 1993 Jun;187(3):735-41. doi: 10.1148/radiology.187.3.8497623.
A misleading susceptibility artifact was originally encountered at magnetic resonance imaging in a patient with multiple cavernous hemangiomas. By using a gradient-recalled echo sequence, the artifact appeared on axial sections as a single ring of enhanced signal intensity within the expected signal void around many of the individual lesions. It was hypothesized and confirmed through phantom experiments with ferromagnetic samples that hemosiderin deposits within each lesion behaved like a point magnetic dipole, causing the intravoxel signal interference patterns that appeared as a ring of enhanced signal intensity. The artifact was therefore found to be entirely susceptibility-induced. Knowledge of the origin and appearance of this new artifact will aid radiologists in the interpretation of susceptibility images and help them avoid misinterpreting a single lesion as multiple contiguous lesions.
一名患有多发性海绵状血管瘤的患者在磁共振成像时最初出现了一种误导性的磁化率伪影。通过使用梯度回波序列，该伪影在轴位图像上表现为许多单个病灶周围预期信号缺失区域内的单个增强信号强度环。通过对铁磁样本进行体模实验推测并证实，每个病灶内的含铁血黄素沉积物表现得像一个点磁偶极子，导致体素内信号干扰模式呈现为增强信号强度环。因此发现该伪影完全是由磁化率引起的。了解这种新伪影的起源和表现将有助于放射科医生解读磁化率图像，并帮助他们避免将单个病灶误判为多个相邻病灶。
