Tomasová Studynková J, Charvát F, Jarosová K, Vencovsky J
Institute of Rheumatology, Na Slupi 4, 12850 Praha 2, Czech Republic.
Rheumatology (Oxford). 2007 Jul;46(7):1174-9. doi: 10.1093/rheumatology/kem088. Epub 2007 May 10.
Acute inflammation in idiopathic inflammatory myopathies (IIM) causes oedema that can be visualized by magnetic resonance imaging (MRI). The inflammatory infiltrate in IIM is thought to be frequently in a focal distribution. The aim of this study is to better evaluate the relationship of MR image of thigh muscles to clinical and histological parameters in patients with IIM.
MRI-short tau inversion recovery (STIR) technique was used to distinguish between affected and non-affected muscles. Computer tomography (CT)-controlled targeted needle biopsy was used for sampling. The intensity of muscle oedema, its extent and total assessment on MRI were evaluated with 10 cm visual analogue scale. The intensity of inflammatory infiltrate was assessed using 5-point grading system. The second MRI and muscle biopsy were performed after the time interval of treatment.
MR scans, muscle biopsy and clinical examination were performed in 29 patients with polymyositis (PM) and dermatomyositis (DM). Paired MRI-affected and MRI-non-affected biopsy samples were obtained from 17 cases. In six cases, the biopsy was available for comparison before and after period of treatment. At the initial examination, it was the intensity of oedema on MRI that was associated with clinical status. Mean intensity of MRI findings significantly decreased in 10 patients where the MRI was available also after treatment. The mean intensity of inflammatory infiltrate in PM/DM patients was 2.5 +/- 0.7 for MRI-affected and 1.7 +/- 0.6 for MRI-non-affected muscles (P < 0.001). Mean intensity of inflammatory infiltrate in the MRI-affected muscles in the first examination (n = 6) was 2.2 +/- 0.8 and did not significantly decrease in the second examination in samples taken after the treatment (2.0 +/- 0.9).
It is mainly the signal intensity in MR scan, which is associated with disease activity in the acute presentation of PM/DM. Muscle biopsy guided by positive MRI finding contains significantly more inflammatory cells than the biopsy taken from MRI non-affected sites. However, even in parts of muscles, which look unaffected on MR scan, the inflammatory cells can be found. The intensity on MR scans decreases significantly after the treatment, but the histologically detected inflammation does not change substantially.
特发性炎性肌病（IIM）中的急性炎症会导致水肿，磁共振成像（MRI）可显示这种水肿。IIM中的炎性浸润被认为常呈局灶性分布。本研究的目的是更好地评估IIM患者大腿肌肉的MRI图像与临床及组织学参数之间的关系。
采用MRI短反转时间反转恢复（STIR）技术区分受累和未受累肌肉。使用计算机断层扫描（CT）引导下的靶向针吸活检进行取样。肌肉水肿的强度、范围及MRI的总体评估采用10厘米视觉模拟量表进行。炎性浸润的强度采用5分分级系统进行评估。在治疗间隔期后进行第二次MRI和肌肉活检。
对29例多发性肌炎（PM）和皮肌炎（DM）患者进行了MR扫描、肌肉活检及临床检查。从17例患者中获取了配对的MRI受累和MRI未受累的活检样本。6例患者在治疗前后均有活检样本可供比较。在初次检查时，MRI上的水肿强度与临床状态相关。在10例治疗后也有MRI检查结果的患者中，MRI表现的平均强度显著降低。PM/DM患者中，MRI受累肌肉的炎性浸润平均强度为2.5±0.7，MRI未受累肌肉为1.7±0.6（P<0.001）。初次检查时（n=6）MRI受累肌肉的炎性浸润平均强度为2.2±0.8，治疗后取样的第二次检查中该强度未显著降低（2.0±0.9）。
在PM/DM的急性表现中，主要是MR扫描中的信号强度与疾病活动相关。MRI阳性结果引导下的肌肉活检所含炎性细胞明显多于从MRI未受累部位获取的活检样本。然而，即使在MR扫描看起来未受累的肌肉部分，也能发现炎性细胞。治疗后MR扫描的强度显著降低，但组织学检测到的炎症变化不大。
