Naganawa Shinji, Ohashi Toshio, Kanou Mai, Kuno Kayao, Sone Michihiko, Ikeda Mitsuru
Department of Radiology, Nagoya University Graduate School of Medicine.
Magn Reson Med Sci. 2015;14(4):257-62. doi: 10.2463/mrms.2014-0118. Epub 2015 Mar 31.
We measured the volume of the endolymphatic space by extending a previously proposed less observer-dependent method of area quantification and compared volume measurements obtained using long (18 min, Image A) and short (8 min, Image B) scan times.
We performed MR imaging of 40 ears in 20 patients with clinically suspected endolymphatic hydrops 4 hours after intravenous administration of single-dose gadolinium-based contrast material (IV-SD-GBCM). Two observers separately measured the ratio of the volume of the endolymph to that of total lymph in the cochlea and vestibule by extending the area ratio measurement method previously reported (Image A and B). The correlation between the values by Image A and B was calculated.
We observed a strong linear correlation between Images A and B in the cochlear images; the Pearson's correlation coefficient (r) was 0.928 for Observer A and 0.926 for Observer B (P < 0.001, for all). A strong linear correlation was also observed in the vestibular images; the Pearson's correlation coefficient (r) was 0.962 for Observer A and 0.968 for Observer B (P < 0.001, for all).
Measurement of endolymphatic volume after IV-SD-GBCM may be feasible using an MR imaging protocol with a reduced scan time of 8 min. This method might facilitate greater use of endolymphatic hydrops imaging in clinical applications.
我们通过扩展先前提出的一种较少依赖观察者的面积量化方法来测量内淋巴间隙的体积，并比较了使用长扫描时间（18分钟，图像A）和短扫描时间（8分钟，图像B）获得的体积测量结果。
我们对20例临床怀疑有内淋巴积水的患者的40只耳朵进行了磁共振成像，在静脉注射单剂量钆基对比剂（IV-SD-GBCM）4小时后进行。两名观察者通过扩展先前报道的面积比测量方法（图像A和B）分别测量耳蜗和前庭内淋巴体积与总淋巴体积的比值。计算图像A和B所得值之间的相关性。
我们在耳蜗图像中观察到图像A和B之间有很强的线性相关性；观察者A的皮尔逊相关系数（r）为0.928，观察者B为0.926（所有P<0.001）。在前庭图像中也观察到很强的线性相关性；观察者A的皮尔逊相关系数（r）为0.962，观察者B为0.968（所有P<0.001）。
使用扫描时间缩短至8分钟的磁共振成像方案测量IV-SD-GBCM后的内淋巴体积可能是可行的。这种方法可能有助于在临床应用中更广泛地使用内淋巴积水成像。
