Gutierrez-Nibeyro Santiago D, Werpy Natasha M, White Nathaniel A, McCutcheon Jill, Weng Hsin-Yi, Christopher John M
Department of Veterinary Clinical Medicine, University of Illinois, Urbana, IL, USA.
Vet Radiol Ultrasound. 2011 Sep-Oct;52(5):521-33. doi: 10.1111/j.1740-8261.2011.01841.x.
High- and low-field magnetic resonance (MR) imaging systems are available for clinical diagnosis of collateral desmopathy of the equine distal interphalangeal joint (DIJ). Knowledge of the normal appearance, size, shape,and signal variation of these ligaments on high- and low-field MR images is essential when assessing desmopathy detected by MR imaging. However, there are no descriptions of the normal features of DIJ collateral ligaments on images obtained with a standing low-field MR system. Low-field MR imaging characteristics of normal collateral ligaments of the DIJ of cadaver feet were corroborated with high-field MR imaging and histologic examination to exclude desmopathy. The size and shape of the collateral ligaments of the DIJ was similar among limbs; however, the signal pattern of the ligaments varied depending on the segment of the ligament being assessed and the MR sequence used. In limbs positioned within the magnet as recommended for clinical MR imaging, collateral ligaments of the DIJ have heterogeneous signal pattern with a peripheral region of increased signal intensity at the level of the middle phalanx that can be confused with a desmopathy.The MR imaging characteristics of normal collateral ligaments of the DIJ are related to their anatomy and fiber configuration. The results of this study support the presence of magic angle effect within the axial margin of the CL of the DIJ at the level of fiber divergence within the proximal to mid-portion of the ligament.
高场和低场磁共振（MR）成像系统可用于马远侧指间关节（DIJ）侧副韧带病的临床诊断。在评估MR成像检测到的韧带病时，了解这些韧带在高场和低场MR图像上的正常外观、大小、形状和信号变化至关重要。然而，目前尚无关于站立位低场MR系统所获图像上DIJ侧副韧带正常特征的描述。通过高场MR成像和组织学检查证实了尸体足部DIJ正常侧副韧带的低场MR成像特征，以排除韧带病。DIJ侧副韧带的大小和形状在各肢体间相似；然而，韧带的信号模式因所评估的韧带节段和所使用的MR序列而异。在按照临床MR成像建议置于磁体内的肢体中，DIJ侧副韧带具有不均匀的信号模式，在中节指骨水平有信号强度增加的周边区域，这可能会与韧带病相混淆。DIJ正常侧副韧带的MR成像特征与其解剖结构和纤维构型有关。本研究结果支持在韧带近侧至中部纤维发散水平的DIJ侧副韧带轴向边缘内存在魔角效应。
