Lakits A, Prokesch R, Scholda C, Bankier A, Weninger F, Imhof H
Department of Ophthalmology, University of Vienna, Austria.
Ophthalmology. 1998 Sep;105(9):1679-85. doi: 10.1016/S0161-6420(98)99038-8.
This study aimed to compare the effectiveness of helical computed tomography (CT) versus conventional CT in the preoperative assessment of metallic intraocular foreign bodies on axial, coronal, and multiplanar reconstruction images in clinical routine.
Prospective comparative trial, alternate assignment of consecutive patients.
Eighteen patients with penetrating eye injuries and suspected metallic intraocular foreign bodies were studied.
Alternate patients were assigned to undergo either helical CT or conventional CT in the axial plane. Both the helical and the conventional data were transferred to a workstation, and reconstructions in the coronal and sagittal planes were performed. Additional direct coronal scanning was performed only when necessary for preoperative assessment.
The quality of the directly obtained axial and coronal, as well as the reconstructed coronal and sagittal images, was assessed for each, imaging method based on the ability to detect and accurately localize foreign bodies. The size of the foreign bodies was measured and compared to the actual diameter. Total examination time and radiation dose delivered to the lens were measured for each imaging method.
All foreign bodies were detected by each scanning method on the axial, the coronal, and on the reconstructed planes. The quality of the axial images was similar for helical and conventional CT. The helical technique provided high-quality reconstructed images comparable in quality to the directly obtained coronal planes in conventional CT. Reconstructions by conventional technique were not useful for preoperative assessment. The examination time for the total orbital volume was 18 seconds for helical CT examinations and 52 seconds for conventional CT examinations. Radiation dose delivered to the lens for the complete examination was 35 mGy for helical CT axial scanning, 56 mGy for conventional CT axial scanning, and 63 mGy for conventional CT coronal scanning.
Helical CT multiplanar imaging offers several significant advantages for the preoperative assessment of metallic intraocular foreign bodies compared to the conventional CT technique in clinical practice, including short examination time, reduced motion artifacts, reduced radiation exposure, and the ability to obtain diagnostically useful coronal and sagittal reconstruction images without the need for additional scanning.
本研究旨在比较螺旋计算机断层扫描（CT）与传统CT在临床常规中对金属性眼内异物进行轴位、冠状位及多平面重建图像术前评估的有效性。
前瞻性对比试验，连续患者交替分配。
对18例穿透性眼外伤且怀疑有金属性眼内异物的患者进行研究。
交替分配患者在轴位平面接受螺旋CT或传统CT检查。将螺旋CT和传统CT数据传输至工作站，并进行冠状位和矢状位重建。仅在术前评估必要时进行额外的直接冠状位扫描。
基于检测和准确定位异物的能力，对每种成像方法直接获得的轴位和冠状位以及重建的冠状位和矢状位图像的质量进行评估。测量异物大小并与实际直径进行比较。测量每种成像方法的总检查时间以及晶状体所接受的辐射剂量。
每种扫描方法在轴位、冠状位及重建平面上均检测到所有异物。螺旋CT和传统CT的轴位图像质量相似。螺旋技术提供的高质量重建图像，其质量与传统CT直接获得的冠状位平面相当。传统技术的重建对术前评估无用。螺旋CT检查整个眼眶容积的时间为18秒，传统CT检查为52秒。螺旋CT轴位扫描整个检查过程中晶状体所接受的辐射剂量为35 mGy，传统CT轴位扫描为56 mGy，传统CT冠状位扫描为63 mGy。
与临床实践中的传统CT技术相比，螺旋CT多平面成像在金属性眼内异物术前评估方面具有若干显著优势，包括检查时间短、运动伪影减少、辐射暴露降低以及无需额外扫描即可获得具有诊断价值的冠状位和矢状位重建图像。
