Wang Fang, Akashi Ken, Murakami Yoshinori, Inoue Yusuke, Furuta Toshihiro, Yamada Haruyasu, Ohtomo Kuni, Kiryu Shigeru
Department of Radiology, Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo, Japan; Department of Radiology, Qi Lu Hospital of Shandong University, Jinan, China.
Division of Molecular Pathology, Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, Japan.
PLoS One. 2014 Apr 17;9(4):e94945. doi: 10.1371/journal.pone.0094945. eCollection 2014.
Due to their small size, lung tumors in rodents are typically investigated using high-field magnetic resonance (MR) systems (4.7 T or higher) to achieve higher signal-to-noise ratios, although low-field MR systems are less sensitive to susceptibility artifacts caused by air in the lung. We investigated the feasibility of detecting lung tumors in living, freely breathing mice with a 1-T compact permanent magnet MR system. In total, 4 mice were used, and MR images of mouse lungs were acquired using a T1-weighted three-dimensional fast low-angle shot sequence without cardiac or respiratory gating. The delineation and size of lung tumors were assessed and compared with histopathological findings. Submillimeter lesions were demonstrated as hyperintense, relative to the surrounding lung parenchyma, and were delineated clearly. Among the 13 lesions validated in histopathological sections, 11 were detected in MR images; the MR detection rate was thus 84.6%. A strong correlation was obtained in size measurements between MR images and histological sections. Thus, a dedicated low-field MR system can be used to detect lung tumors in living mice noninvasively without gating.
由于啮齿动物肺部肿瘤体积较小，通常使用高场磁共振（MR）系统（4.7 T或更高）进行研究，以获得更高的信噪比，尽管低场MR系统对肺部空气引起的磁化率伪影不太敏感。我们研究了使用1-T紧凑型永磁MR系统检测自由呼吸的活体小鼠肺部肿瘤的可行性。总共使用了4只小鼠，使用T1加权三维快速低角度激发序列在没有心脏或呼吸门控的情况下采集小鼠肺部的MR图像。评估肺部肿瘤的轮廓和大小，并与组织病理学结果进行比较。相对于周围肺实质，亚毫米级病变表现为高信号，且轮廓清晰。在组织病理学切片验证的13个病变中，MR图像检测到11个；因此，MR检测率为84.6%。MR图像和组织学切片之间的大小测量结果具有很强的相关性。因此，专用的低场MR系统可用于在无门控的情况下无创检测活体小鼠的肺部肿瘤。
