Gupta Rajiv, Bartling Soenke H, Basu Samit K, Ross William R, Becker Hartmut, Pfoh Armin, Brady Thomas, Curtin Hugh D
Department of Radiology, Massachusetts General Hospital, Boston 02114, USA.
AJNR Am J Neuroradiol. 2004 Sep;25(8):1417-24.
A CT scanner employing a digital flat-panel detector is capable of very high spatial resolution as compared with a multi-section CT (MSCT) scanner. Our purpose was to determine how well a prototypical volume CT (VCT) scanner with a flat-panel detector system defines fine structures in temporal bone.
Four partially manipulated temporal-bone specimens were imaged by use of a prototypical cone-beam VCT scanner with a flat-panel detector system at an isometric resolution of 150 microm at the isocenter. These specimens were also depicted by state-of-the-art multisection CT (MSCT). Forty-two structures imaged by both scanners were qualitatively assessed and rated, and scores assigned to VCT findings were compared with those of MSCT.
Qualitative assessment of anatomic structures, lesions, cochlear implants, and middle-ear hearing aids indicated that image quality was significantly better with VCT (P < .001). Structures near the spatial-resolution limit of MSCT (e.g., bony covering of the tympanic segment of the facial canal, the incudo-stapedial joint, the proximal vestibular aqueduct, the interscalar septum, and the modiolus) had higher contrast and less partial-volume effect with VCT.
The flat-panel prototype provides better definition of fine osseous structures of temporal bone than that of currently available MSCT scanners. This study provides impetus for further research in increasing spatial resolution beyond that offered by the current state-of-the-art scanners.
与多层CT（MSCT）扫描仪相比，采用数字平板探测器的CT扫描仪具有非常高的空间分辨率。我们的目的是确定具有平板探测器系统的原型容积CT（VCT）扫描仪在颞骨中对精细结构的显示效果如何。
使用具有平板探测器系统的原型锥形束VCT扫描仪，在等中心处以150微米的等距分辨率对4个部分处理的颞骨标本进行成像。这些标本也通过最先进的多层CT（MSCT）进行描绘。对两种扫描仪成像的42个结构进行定性评估和评分，并将VCT检查结果的评分与MSCT的评分进行比较。
对解剖结构、病变、人工耳蜗和中耳助听器的定性评估表明，VCT的图像质量明显更好（P <.001）。在MSCT空间分辨率极限附近的结构（例如，面神经管鼓室段的骨覆盖、砧镫关节、前庭导水管近端、蜗轴间间隔和蜗轴）在VCT上具有更高的对比度和更小的部分容积效应。
平板原型对颞骨精细骨质结构的显示优于目前可用的MSCT扫描仪。本研究为进一步提高空间分辨率的研究提供了动力，使其超越当前最先进扫描仪的水平。
