Dedicated Cone-Beam CT System for Extremity Imaging
Dedicated Cone-Beam CT System for Extremity Imaging
复制标题
DOI：
10.1148/radiol.13130225
复制
发表时间：
2014-03-01
期刊：
影响因子：
19.7
通讯作者：
Siewerdsen, Jeffrey H.
中科院分区：
文献类型：
--
作者：
Carrino, John A.;Al Muhit, Abdullah;Siewerdsen, Jeffrey H.
目的：为了提供初步评估的图像质量和剂量的锥束计算机断层扫描（CT）扫描仪专用于四肢imaging.Materials和Methods：一个原型锥束CT扫描仪已开发用于四肢成像，包括负重下肢。初步的技术评估包括评价作为千伏峰值和电子管输出函数测量的辐射剂量（单位：毫安秒），根据信号差-噪声比（SDNR）评估的对比度分辨率，通过使用来自体模的线对模块半定量评估的空间分辨率，由专家CT观察员对尸体图像进行潜在诊断价值和图像伪影的定性评价结果：标称扫描协议（80 kVp，108 mAs）的剂量为9 mGy（在CT剂量指数体模中心测量的绝对剂量）。使用80 kVp扫描技术，SDNR最大化，对比度分辨率足以显示肌肉、脂肪、韧带和/或肌腱、软骨关节间隙和骨。在轴向平面的空间分辨率超过15线对每厘米。与X射线散射（在患者较厚的区域-例如，膝关节）、射束硬化（关于皮质骨-例如，股骨干）和锥形射束伪影（在沿着扫描平面定向的关节间隙表面-例如，指间关节）相关的条纹对可视化造成轻微障碍。尸体图像（肘，手，膝盖，和脚）表现出良好的可见性，骨细节和良好的软组织能见度适合于广泛的肌肉骨骼indications.Conclusion：一个专用的四肢锥束CT扫描仪能够成像的上肢和下肢（包括负重检查）提供了足够的图像质量和有利的剂量特性，以保证进一步评价临床使用。(C)RSNA，2013年
Purpose: To provide initial assessment of image quality and dose for a cone-beam computed tomographic (CT) scanner dedicated to extremity imaging.Materials and Methods: A prototype cone-beam CT scanner has been developed for imaging the extremities, including the weight-bearing lower extremities. Initial technical assessment included evaluation of radiation dose measured as a function of kilovolt peak and tube output (in milliampere seconds), contrast resolution assessed in terms of the signal difference- to- noise ratio (SDNR), spatial resolution semi-quantitatively assessed by using a line-pair module from a phantom, and qualitative evaluation of cadaver images for potential diagnostic value and image artifacts by an expert CT observer (musculoskeletal radiologist).Results: The dose for a nominal scan protocol (80 kVp, 108 mAs) was 9 mGy (absolute dose measured at the center of a CT dose index phantom). SDNR was maximized with the 80kVp scan technique, and contrast resolution was sufficient for visualization of muscle, fat, ligaments and/or tendons, cartilage joint space, and bone. Spatial resolution in the axial plane exceeded 15 line pairs per centimeter. Streaks associated with x-ray scatter (in thicker regions of the patient-eg, the knee), beam hardening (about cortical bone-eg, the femoral shaft), and cone-beam artifacts (at joint space surfaces oriented along the scanning plane-eg, the interphalangeal joints) presented a slight impediment to visualization. Cadaver images (elbow, hand, knee, and foot) demonstrated excellent visibility of bone detail and good soft-tissue visibility suitable to a broad spectrum of musculoskeletal indications.Conclusion: A dedicated extremity cone-beam CT scanner capable of imaging upper and lower extremities (including weight-bearing examinations) provides sufficient image quality and favorable dose characteristics to warrant further evaluation for clinical use. (C) RSNA, 2013