Malghem Jacques, Lecouvet Frédéric E, François Robert, Vande Berg Bruno C, Duprez Thierry, Cosnard Guy, Maldague Baudouin E
Cliniques Universitaires St Luc, Université Catholique de Louvain, 10 av Hippocrate, 1200 Brussels, Belgium.
Skeletal Radiol. 2005 Feb;34(2):80-6. doi: 10.1007/s00256-004-0843-1. Epub 2004 Oct 8.
To explain a cause of high signal intensity on T1-weighted MR images in calcified intervertebral disks associated with spinal fusion.
Magnetic resonance and radiological examinations of 13 patients were reviewed, presenting one or several intervertebral disks showing a high signal intensity on T1-weighted MR images, associated both with the presence of calcifications in the disks and with peripheral fusion of the corresponding spinal segments. Fusion was due to ligament ossifications (n=8), ankylosing spondylitis (n=4), or posterior arthrodesis (n=1). Imaging files included X-rays and T1-weighted MR images in all cases, T2-weighted MR images in 12 cases, MR images with fat signal suppression in 7 cases, and a CT scan in 1 case. Histological study of a calcified disk from an anatomical specimen of an ankylosed lumbar spine resulting from ankylosing spondylitis was examined.
The signal intensity of the disks was similar to that of the bone marrow or of perivertebral fat both on T1-weighted MR images and on all sequences, including those with fat signal suppression. In one of these disks, a strongly negative absorption coefficient was focally measured by CT scan, suggesting a fatty content. The histological examination of the ankylosed calcified disk revealed the presence of well-differentiated bone tissue and fatty marrow within the disk.
The high signal intensity of some calcified intervertebral disks on T1-weighted MR images can result from the presence of fatty marrow, probably related to a disk ossification process in ankylosed spines.
解释与脊柱融合相关的钙化椎间盘在T1加权磁共振成像上出现高信号强度的原因。
回顾了13例患者的磁共振和放射学检查结果，这些患者有一个或多个椎间盘在T1加权磁共振成像上显示高信号强度，同时伴有椎间盘钙化以及相应脊柱节段的周边融合。融合的原因包括韧带骨化（n = 8）、强直性脊柱炎（n = 4）或后路关节融合术（n = 1）。所有病例的影像文件均包括X线片和T1加权磁共振成像，12例有T2加权磁共振成像，7例有脂肪信号抑制的磁共振成像，1例有CT扫描。对一例因强直性脊柱炎导致的腰椎关节强硬解剖标本中的钙化椎间盘进行了组织学研究。
在T1加权磁共振成像以及所有序列上，包括那些有脂肪信号抑制的序列，椎间盘的信号强度与骨髓或椎旁脂肪的信号强度相似。在其中一个椎间盘中，通过CT扫描局部测量到一个强负吸收系数，提示存在脂肪成分。对关节强硬的钙化椎间盘进行组织学检查发现椎间盘内存在分化良好的骨组织和脂肪骨髓。
一些钙化椎间盘在T1加权磁共振成像上的高信号强度可能是由于脂肪骨髓的存在，这可能与关节强硬脊柱中的椎间盘骨化过程有关。
