【摘要】 目的通过对头颅标本后部眼眶填砂的CT扫描测量值和量筒测量值的对比,选择CT扫描测量的最佳窗宽、窗位和层厚。方法从备用的颅骨标本中随机选出5具标本,进行在13组不同窗宽和窗位组合下的2mm层厚的CT冠状扫描和后部眼眶容积测量,再将所得的容积和量筒直接测量法所得的后部眼眶容积进行对比,选择出误差最小、最精确的窗宽和窗位组合,在此组合下对20具(40只眼眶)颅骨标本的后部眼眶容积进行不同层厚(2mm、3mm和5mm层厚CT机上一般不设4mm层厚)的扫描,将所得测量值和量筒直接测量值进行比较研究。结果当窗宽和窗位为1600HU和500HU时,误差率最小;后部眼眶砂子体积平均值:CT测量法为(15.91±1.62)ml,量筒直接测量法为(15.87±1.70)ml,两种方法对比无明显差别(p>0.05);后部眼眶砂子体积(直接测量法):左眼为(16.04±1.84)ml,右眼为(15.70±1.62)ml,左右眼无显著性差异(p>0.05);2mm、3mm和5mm层厚测量的结果分别是:(15.91±1.62)ml、(15.77±1.81)ml、(14.99±1.67)ml,2mm和3mm两组对比没有显著性差异(p>0.05),3mm和5mm两组对比有显著性差异(p<0.05)。结论三维螺旋CT测量标本眼眶中砂子体积时,窗宽和窗位为1600HU和500HU时是最佳组合;采用3mm层厚CT扫描,可相对减少患者的X线辐射量和放射科医生的工作量,省时、省力且对人体损伤小,适合于临床实际应用;左、右眼后部眶容积值无明显差异;三维螺旋CT是测量眼眶容积值的一种精确、可靠的测量方法。更多还原

【Abstract】 Objective To choose the suitable layer thickness、window level and window width after the comparision of the volumes of sand filled in retral orbit of skull sampals measured by CT and done by volumetric. Methods Firistly 5 skull sampals were selected in random, and whose orbital capacity after the eyeball’s equator were measured in 13 groups differrent window level and window width and 2mm layer thick- ness by CT in coronary scan. Results The average volumes of sand filled in retral orbit are: (15.91 ± 1.62)ml measured by CT, (15.87 ± 1.70)ml measured by volumetric, there is no significant difference between the two methods (p>0.05); direct measurement: left eye is (16.04 ± 1.84)ml, right eye is (15.70 ± 1.62)ml, there is no significant difference between left and right eye (p>0.05); the results measured by 2mm、3mm and 5mm are (15.91 ± 1.62)ml、(15.77 ± 1.81)ml、(14.99 ± 1.67)ml,there is no significant difference between 2mm and 3mm (p>0.05), there is significant difference between 3mm and 5mm (p<0.05). Conclusion Three-dimensional CT measurement of orbital volume is an accurate and reliable measurement method. when we select window level and winow width is 1600HU and 500HU, which is the best combination; when we select 3mm layer thickness, which could comparatively reduce the radition of patients and doctor’s work, and the suffer on body is less, and fits clinical application in fact.更多还原