Evaluation of lung perfusion MRI for various lung diseases

本文对放射性和博来霉素诱发的间质性肺炎犬模型进行了动态灌注MR成像，并对急性期、慢性期和纤维化期间质性肺炎的灌注特征进行了研究。对健康志愿者和急性、慢性、纤维化放射性肺炎、急性间质性肺炎、UIP、UIP复发、肺气肿、细菌性肺炎等肺部疾病患者进行了动态灌注MR成像检查。在肺气肿，其中血管床减少，动态MR成像的增强效果较低。间质性肺炎急性期动态增强效果较高。纤维化期动态增强表现为早期低强化，但逐渐增强。这些结果与实验研究结果相似。此外，动态MR成像可通过观察造影剂的血流动力学来评价全身灌注增加的情况，静脉注射后，造影剂首先分布于血管内，其次分布于血管外。通过对MR灌注成像动态模式的分析，该技术有助于评价这两个室，并有助于鉴别活动性和非活动性间质性肺炎。

We evaluated the dynamic perfusion MR imaging to differentiate the various lung diseases, which may be difficult to assess for scintigraphic technique and morphologic computed tomography.Experimentally the dynamic perfusion MR studies were performed to radiation- and bleomycin-induced interstitial pneumonia of dogs and were repeated to determine the perfusion characteristics of acute, chronic and fibrotic phase of interstitial pneumonia. The results suggested that the dynamic perfusion MR imaging may assess the activity of the experimental interstitial pneumonia.Clinically healthy volunteers and patients of various lung diseases such as acute, chronic and fibrotic radiation pneumonitis, acute interstitial pneumonia, UIP, relapse of UIP, pulmonary emphysema, bacterial pneumonia and so on, were examined for the dynamic perfusion MR imaging. In pulmonary emphysema, where vascular bed is decreased, the enhancement effect of dynamic MR imaging was lower. In acute phase of interstitial pneumonia, enhancement effect of dynamic MR imaging was higher. Although in fibrotic phase, dynamic pattern showed the lower enhancement in early phase of dynamic study but gradually the enhancement effect was increased. Those results were similar to that of experimental study. In addition, dynamic MR imaging could evaluate the increased systemic perfusion by the observation of the hemodynamics of contrast material.After intravenous injection, contrast material is distributed first to intravascular space and next to extravascular space. By analysis of dynamic pattern of perfusion MR imaging, this technique is useful to evaluate this two compartments and to differentiate the active or inactive interstitial pneumonia.