Evaluation on Accuracy of Pancreatic Volume Using Multislice Spiral CT

目的 研究多层螺旋CT测量胰腺体积的准确性.资料与方法 多层螺旋CT扫描胰腺模型及胰腺正常患有其他疾病的患者,由有5年以上CT工作经验的放射科医师测量胰腺体积并记录.结果 胰腺模型体积CT测量值与实际值差异无统计学意义(t=1.648,P=0.134),这两者间的一致性很高(ICC=1.000,P=0.000);可重复性分析中,CT测量胰腺体积观察者内的差异及观察者间的差异无统计学意义(P＞0 05),一致性很高(所有ICC ＞0 99,P=0 000).结论 多层螺旋CT测量胰腺体积准确、可靠,可重复性较高.     

低剂量多层螺旋CT测量腹部脂肪的实验研究

目的 应用低剂量多层螺旋CT(multi-slice spiral computed tomography,MSCT)测量腹部脂肪的含量.材料与方法用猪肉及内脏器官模拟腹部成分制作模型,在管电压(kV)不变的条件下,测量不同管电流(mA)时,皮下、肌间、腹内脂肪的CT值和腹部脂肪体积百分率以及CT剂量指数(CTDI)值.结果 在kV不变的条件下,mA不同时,皮下、肌间和腹内脂肪的CT值以及腹部脂肪体积百分率差异无统计学意义(P＞0.05),而不同mA时,CTDI差异有统计学意义(P＜0.01);mA与各部脂肪CT值和腹部脂肪体积百分率无相关性(P＞0.05),mA与CTDI成正相关(P＜0.01).结论 腹部脂肪CT值和脂肪体积百分率不随mA降低而发生变化,在低剂量条件下MSCT可以完成腹部脂肪含量的测量.     

多层螺旋CT兔牙颌测量准确性可靠性研究

目的 研究应用多层螺旋CT三维影像进行牙颌测量的准确性和可靠性.方法 选取12只雄性新西兰大白兔,制取上颌超硬石膏模型；并进行头颅64排多层螺旋CT(飞利浦Brilliance CT 64排,飞利浦医疗系统公司,美国)扫描获得兔牙颌三维影像.以石膏模型高精度数显游标直接测量作为金标准,对多层螺旋CT测量结果应用均数差和一致性相关系数(CCC)检验其准确性和可靠性.结果 64排多层螺旋CT兔牙颌三维影像测量具有良好可靠性(CCC:0.6961～0.9506),且与石膏模型测量的一致性很高(CCC:0.8547～0.9796)；配对t检验和误差分析显示64排多层螺旋CT检测的准确性高(P值=0.067～0.817).结论 64排多层螺旋CT兔牙颌三维影像具有良好的测量准确性和可靠性.     

多层螺旋CT测量猪肾体积准确性的相关性研究

目的:评价多层螺旋CT(MSCT)不同体积测量软件猪肾体积测量的准确性。方法:对20个新鲜离体猪肾进行MSCT扫描,分别用改良排水法、3D Object Editor、Voume进行体积测量,对比3D Object Editor、Volume与排水法测量体积之间的相关性。结果:3D测量值与真实值进行配对t检验,t=0.1280.05,两组间差异无显著意义,相关系数r1=0.983(P0.01),呈显著性相关;Volume测量值与真实值进行配对t检验,t=0.5040.05,两组间差异无显著意义.相关系数r2=0.896(P0.01),呈高度相关;3D测量值与真实值平均差异比为(-0.730±2.398)%,Volume测量值与真实值平均差异比为(-0.745±2.394)%,两种差异比经配对t检验,t=0.0830.05,两组间差异无显著意义,相关系数r=1.000。结论:3D Object Editor测量的体积与真实体积的相关性更高(r1r2),准确度高。     

螺旋CT甲状腺体积测量的可靠性及临床应用

目的 评价螺旋cT甲状腺体积测量的可靠性并研究不同人群甲状腺体积的差异.资料与方法 经颈部CT检查排除甲状腺疾病的患者124例,从中随机抽出25例行甲状腺螺旋CT体积测量的可靠性分析,并对124例按人群组进行测量研究.可靠性分析由两名观察者独立测量,每名观察者均测量2次.同一观察者2次间和两名观察者间测量的差异用重复测量的方差分析比较,相互关系用组内相关系数(ICC)描述.两名观察者间的可靠性分析用Cronbach's alpha系数描述.对124例甲状腺体积的测量则由一名观察者测量2次,取其均值.观察甲状腺体积在各年龄段及性别间的差异、体积和年龄间的相关关系.结果 观察者甲2次测得甲状腺平均体积为(11.57±5.25)cm3和(11.60±5.18)cm3;F=0.32,P=0.58,ICC=0.9984.观察者乙2次测量的甲状腺平均体积为(11.52±5.18)cm3和(11.58±5.19)cm3;F=1.92,P=0.18,ICC=0.9990.两名观察者所测体积的均值分别是(11.59±5.21)cm3和(11.55±5.18)cm3;F=0.95,P=0.34,ICC=0.9993,Cronbach's alpha系数=0.9996.124例甲状腺平均体积是(12.12±6.19)cm3,年龄与甲状腺体积间r.=-5.70,P=0.00.男性平均体积(13.02±4.81)cm3,女性(12.01±7.76)cm3,P=0.015.结论 螺旋CT甲状腺体积测量可靠性高,甲状腺体积随衰老减小,男性甲状腺平均体积较女性大.     

肺肿块轮廓特征辨识的观察者之间的一致性分析

目的 研究肺肿块CT毛刺征、分叶征辨识的个体间差异,确定在临床工作中这2种征象辨识的稳定性.方法 5位不同工作经历的影像医师作为观察者,对经病理证实的49例肺肿块的 CT图片进行评价,确定毛刺征、分叶的有无及其程度.使用χ2检验和Kappa系数(K值)进行统计学研究.结果 毛刺的总体检出率在5位观察者之间差异无统计学差异(检出率平均39.2%,范围:32.7%~54.1%;χ2=24.892,df=4,P=0.213),对毛刺各亚型检出率的判断差异显著,有统计学意义(χ2=46.655 5,df=20,P=0.001[双尾]),K值从0.277(P=0.041)~0.738(P=0.000)不等.分叶征的有无及其亚型的辨识,5位观察者的总体检出率均存在统计学差异(χ2=34.563,df=4,P=0.000和χ2=93.323,df=16,P=0.000[双尾]),K值仅为0.036(P=0.342)~0.453(P=0.001).结论 肺肿块轮廓征象的主观判断、手工测量个体之间差异较大.     

孤立性肺结节CT动态增强扫描的层面优化及临床应用

目的利用选层重组的方法改善孤立性肺结节(SPN)CT动态增强扫描各延时像测量层面的一致性,并探讨其临床应用价值。方法(1)对3种均质液体行CT螺旋扫描并在Z轴方向同层厚任意多平面重组,比较其原始扫描图像及重组图像密度测量值的差异。(2)对72例SPN患者行螺旋CT动态增强扫描,运用一定的选层重组的方法保证各延时像测量层面的一致性。并对其中46例经病理及临床证实的SPN的CT动态增强特点进行评价,评估其增强前后的CT值、强化峰值、SPN与主动脉的强化值比。结果(1)不同密度的均质液体同层厚的原始扫描图像及重组图像间密度测量值差异无统计学意义(F=1.544,P>0.05);(2)67例SPN选层重组前、后各延时像测量层面一致率分别为20.98%(14/67)和97.01%(65/67),其差异有统计学意义(χ2=80.22,P=0.00)。多层螺旋CT对5例SPN的选层重组全部成功。(3)SPN的CT动态增强各延时像测量层面一致性优化以后,恶性结节与炎性结节强化峰值[(38.48±14.32)、(42.48±11.55)HU]和结节与主动脉强化值比[(19.64±9.52)、(21.14±7.77)%]均明显高于良性结节[(9.52±3.78)HU、(3.41±1.86)%];P值均<0.01。炎性结节的强化峰值、结节与主动脉强化值比[(42.48±11.55)HU、(21.14±7.77)%]与恶性结节[(38.48±14.32)HU、(19.64±9.52)%]间的差异无统计学意义(P值均>0.05)。CT动态增强选层重组保证各延时像测量层面一致性后,使其对SPN定性的准确率由78%提升至80%。结论螺旋CT扫描Z轴方向同层厚任意重组对均质物质的密度值的测量无明显影响。CT动态增强扫描各延时像测量层面一致性的优化可进一步客观反映SPN的动态增强情况,有利于其形态学的比较及CT值的测量,有望提高其对孤立性肺结节鉴别诊断的能力。     

脑瘤灌注CT不同层厚CBV和rCBV测量的可重复性研究

目的:评价灌注CT采用不同层厚测量脑瘤脑血容量(cerebral blood volume, CBV)和相对脑血容量(relative cerebrat blood volume, rCBV)的可重复性.方法:分析52例不同类型脑瘤病人的灌注CT数据,比较不同层厚组CBV和rCBV测量结果的差别,计算变异系数(coefficient of variation, CV)及配对相对差值.结果:观察者2不同层厚组CBV和 rCBV各自的测量值有统计学差异显著性(P<0.05).10mm层厚组CBV测量的观察者间CV和配对相对差值低于5mm层厚组.同一层厚CBV的观察者间CV和配对相对差值低于rCBV者.10mm层厚组观察者2两次CBV和rCBV测量值有统计学差异显著性(P<0.05).观察者2观察者内CBV和rCBV的CV和配对相对差值均明显高于另两位观察者.结论:两种不同层厚灌注CT CBV和rCBV测量均有较高的可重复性,适当的培训有助于提高测量的稳定性.     

低剂量64层螺旋CT前瞻性心电门控技术测量冠状动脉钙化积分的可重复性研究

目的 探讨低剂量64层CT测定冠状动脉钙化积分的可重复性.方法 43例冠状动脉钙化的患者连续进行2次64层螺旋CT扫描,管电流分别为100 mAs和55 mAs,其余参数不变,由2名放射科医生测定钙化积分,计算前后2次扫描差值;同时测量升主动脉的CT值的均数及标准差.结果 2次扫描在观察者和观察者内部差值的绝对值多数在50以内(分别为81.4%和86.5%).低剂量扫描对不同测量者无明显统计学差异(P=0.883和0.952);取平方根转换后均具有明显相关(r均为0.998).采用管电流55 mAs,所测均数与2倍标准差之和低于130 HU,可将辐射剂量降低0.6 mSv.结论 低剂量前门控64层CT钙化积分扫描在降低辐射剂量的同时,图像满足测量需要,具有较高的可重复性.     

应用人工智能对肺结节直径测量:观察者内、观察者间差异

目的比较观察者内、观察者间、人工智能与手动测量对肺结节轴位最大径测量的一致性与重复性。方法收集2018年6月1日～2018年6月30日间在我院检查发现70个肺结节(≤30mm,≥3mm)的CT影像资料进行分析。观察者内、观察者间、人工智能与人工手动测量并记录最大直径。应用配对样本t检验及Pearson相关分析评估2种直径测量方法的差异、Bland-Altman法评估2种方法的重复性。结果人工智能与人工手动直径测量、同一观察者不同时间段的直径均无明显差异(P=0.247,P=0.909);而不同观察者所测量的肺结节直径间差异具有显著性(P=0.012)。同一结节不同时间观察者间的测量重复性最佳(RD 95%一致性区间为-1.04%～1.32%,均值为0.14%)及相关性最好(r=0.975,P=0.000)。结论不同观察者之间测量肺结节直径差异具有显著性,但人工智能自动测量结节直径与人工手动测量差异无显著性,具有较好的一致性。     

兰州地区成人脾脏容积多层螺旋CT测量

目的:探讨正常成人脾脏容积多层螺旋CT测量的方法和正常值,并研究脾脏容积与脾脏各径线长度及肋单元的相关性。方法:应用多层螺旋CT自带的Volume软件对400例正常成人脾容积进行测量。结果:400例检查者脾容积的平均值为(173.94±52.17)cm3,200例男性脾容积平均值为(184.99±51.01)cm3,200例女性脾容积平均值为(162.90±51.08)cm3。脾容积与肋单元相关系数r=0.32,与上下径相关系数r=0.62,与前后径相关系数r=0.64,与脾厚径相关系数r=0.52,P0.01。结论:多层螺旋CT脾容积测量方法简便,结果较其他方法更为准确。脾脏上下径、前后径和脾厚径与脾容积相关性较大,两项以上超过正常上限,可做为判断脾脏增大的初步指标。     

多层螺旋CT胰腺三期增强扫描的临床价值

目的　探讨多层螺旋CT(MSCT)胰腺三期增强扫描的临床价值。资料与方法　随机选择 4 0例无胰腺疾病患者 ,进行平扫及三期 (动脉期、胰腺期及肝脏期 )增强扫描。分别测量平扫及三期增强扫描时胰腺实质密度 ,根据三期增强扫描胰腺实质密度较增强前提高程度 ,比较三期增强扫描胰腺实质强化的情况 ;同时分别评价动脉期与胰腺期胰周血管的显示率及显示程度 ,并行统计学分析。结果　三期增强扫描中 ,胰腺期胰腺实质密度较平扫提高程度最为明显 ,胰腺期与动脉期及胰腺期与肝脏期 ,差异均非常显著 (P <0 .0 0 1)。对于胰周大动脉显示率 ,动脉期与胰腺期无统计学差异 (P >0 .0 5 ) ,而对其显示程度 ,则差异非常显著 ,动脉期明显优于胰腺期 (P <0 .0 0 1) ;对于胰周大静脉、胰周主要动、静脉的显示率及显示程度 ,动脉期与胰腺期则均有显著性差异 (P <0 .0 1)。结论　MSCT胰腺检查 ,一般宜行三期增强扫描 :动脉期、胰腺期及肝脏期 ;若已于MSCT检查前明确为不可切除性胰腺癌 ,亦可行双期增强扫描 :胰腺期及肝脏期。     

Craniofacial measurements based on 3D-CT volume rendering: implications for clinical applications

OBJECTIVES: This study was designed to determine the precision and accuracy of anthropometric measurements using three-dimensional computed tomography (3D-CT) volume rendering by computer systems for craniofacial clinical applications, and to compare the craniometric landmarks using bone and soft tissue protocols. METHODS: The study population consisted of 13 cadaver heads that were examined with spiral CT. The archived CT data were transferred to a workstation, and 3D-CT volume rendered images were generated using computer graphics tools. Linear measurements (n = 10), based upon conventional craniometric anatomical landmarks (n = 08), were identified in 2D-CT and in 3D-CT images by two radiologists twice each independently, and then performed by 3D-CT imaging using a computer graphics systems using bone and soft tissue protocols. In total, 520 imaging measurements were made. The soft tissues were subsequently removed from the cadaver heads and the measurements were repeated using an electromagnetic 3 Space trade mark digitizer. RESULTS: The results demonstrated no statistically significant difference between interobserver and intraobserver measurements or between imaging and physical measurements in both 3D-CT protocols. The standard error was found to be between 0.45% and 1.44% for all the measurements in both protocols, indicating a high level of precision. Furthermore, there was no statistically significant difference between imaging and physical measurements (P > 0.01). The error between the mean actual and mean 3D-based linear measurements was 0.83% for bone and 1.78% for soft tissue measurements, demonstrating high accuracy of both 3D-CT protocols. CONCLUSIONS: 3D-CT volume rendering images using craniometric measurements can be used for anthropological studies involving craniofacial applications.     

Accuracy and reliability of thyroid volumetry using spiral CT and thyroid volume in a healthy, non-iodine-deficient Chinese adult population

Objective

The purpose of this study was to assess the accuracy and reliability of thyroid volumetry using spiral CT and to investigate thyroid volumes for a healthy, non-iodine-deficient adult population in southwestern region of China.

Materials and methods

Spiral CT was performed in phantoms and adult subjects with normal thyroid, and the volumes were measured by observers with 5 years or more of CT experience. The phantom volumes and the thyroid volumes of all subjects were noted.

Results

For the thyroid phantoms, there was no significant difference between the true and CT calculated volumes (t = 0.862, P = 0.399), and the correlation was excellent (ICC = 0.9995, P = 0.000). In the subjects for reliability analysis, the intraobserver or interobserver differences for CT volumetric measurement of thyroid were not significant (P > 0.05). The intraobserver or interobserver correlations were very high (ICC > 0.99, P < 0.001). In the subjects for population analysis, the median of the thyroid volumes was 11.45 cm³. The nonparametric Mann-Whitney U-test showed no significant difference for the thyroid volume between sexes (U = 4388.00, Z = −1.118, P = 0.264). The nonparametric Kruskall-Wallis test showed no significant difference in all age groups (χ² = 13.466, P = 0.062). There was a slight negative correlation between the thyroid volume and age (r_s = −0.166, P = 0.019).

Conclusion

The accuracy and reliability of multi-slice spiral CT in measuring thyroid volume are very high. The thyroid volumes are not significantly difference between genders or among decades for the healthy, non-iodine-deficient adult population in southwestern region of China.     

Validation of ultrafast computed tomographic left ventricular volume measurement

Left ventricular volume has been measured with ultrafast computed tomography. However, the accuracy with which this can be done is unknown. We therefore imaged with ultrafast computed tomography 11 rectangular phantoms, 20 to 225 ml, and 17 left ventricular casts, 15 to 112 ml. Two observers planimetered serial tomographic images and computed volume from sequential tomograms. There was no significant inter- or intraobserver difference in measurement of phantoms. Deviation of ultrafast computed tomographic volume from true phantom volume was -0.1 +/- 3.5% SD, range 9.0 to -7.6%. Correlation of true phantom volume with ultrafast computed tomographic volume was 0.99, SEE = 1.9 ml. No significant difference was observed between merged and single ultrafast computed tomographic scanning sequences. Left ventricular cast volume determined by ultrafast computed tomography deviated from true volume by 6% +/- 20%, range 54% to -45%. Correlation of true volume with ultrafast computed tomographic volume was 0.99, SEE = 5.1 ml. There was no interobserver significant difference in measurement of left ventricular cast volume. Correlation between ultrafast computed tomographic volume and cineradiographic volume of the same left ventricular casts was 0.99, SEE = 4.4 ml. Thus, phantom volumes can be measured accurately without significant intra- or interobserver variation. Merged scanning sequences did not influence volume determination. Left ventricular cast volume determination was comparable to that obtained with cineradiography.     

Spiral versus electron-beam CT for coronary artery calcium scoring

PURPOSE: To determine differences in coronary artery calcium detection, quantification, and reproducibility, as measured at electron-beam computed tomography (CT) and subsecond spiral CT with retrospective electrocardiogram gating in an asymptomatic adult population. MATERIALS AND METHODS: Seventy subjects asymptomatic for coronary heart disease underwent both electron-beam CT and subsecond spiral CT. In all subjects, two images each were obtained with both scanners. Two experienced readers using three different algorithms scored each of the four scans: one score for the electron-beam CT images and two scores for the spiral CT images. RESULTS: With a 130-HU threshold for the quantification of calcium, there were no significant differences in interscan and interobserver variation in calcium scores between the electron-beam CT and spiral CT images. There was greater interobserver (P <.001) and interscan (P <.03) variation in scores when a 90-HU threshold was used for spiral CT images. With a 130-HU threshold, when calcium scores were used for clinical risk stratification, there was a significant difference between the results obtained with electron-beam CT and those obtained with spiral CT (P <.05). CONCLUSION: Spiral CT has not yet proved to be a feasible alternative to electron-beam CT for coronary artery calcium quantification. There are systematic differences between calcium scores obtained with single-detector array subsecond spiral CT and those obtained with electron-beam CT.     

Interobserver and intraobserver variability in the assessment of pulmonary nodule size on CT using film and computer display methods

RATIONALE AND OBJECTIVES: A critical element in determining biologic behavior of pulmonary nodules is volume and temporal volume change. We evaluate variability in nodule volume among readers and measuring methods. MATERIALS AND METHODS: 55 small (<2 cm) lung nodules were measured in long- and short-axis dimensions independently by 4 radiologists, using 3 methods: 1) hard copy, 2) GE Advantage Windows workstation (GE Healthcare, Milwaukee, WI), 3) Siemens IMACS workstation (Siemens Medical Systems, Iselan, NJ). Nodule margin was recorded as smooth, lobulated, or spiculated. Volume was calculated from diameter measurements. Variability in nodule volume was evaluated within each reader, between readers, and across measurement tools. RESULTS: Mean nodule short-axis diameter was 5.3 mm; mean long-axis diameter 7.2 mm. There was statistically significant variation among readers and measurement method for nodule volume. Volume was significantly larger using hard-copy measurements (51.9%-54.1% variation; P < .0001) than either workstation, and not different between workstations. There was greater intraobserver variability in volume using the hard-copy method, and no difference between workstation methods. Volumes based on measurements from one reader were consistently lower than those from other readers (P = < .001, .003, and .02); volume was consistently larger for another reader (P < .0001, .03, and .12). Reader agreement for nodule margin was good to excellent. CONCLUSION: Considerable interobserver and intraobserver variability in measuring nodules exists using hard-copy and computer tools. Since a small change in diameter indicates a much larger change in volume, this may be significant when using early repeat CT to follow small pulmonary nodules. Computer-aided diagnostic tools that reproducibly measure nodule volume are strongly needed.     

Quantification of coronary plaque by 64-slice computed tomography: a comparison with quantitative intracoronary ultrasound

BACKGROUND: Noninvasive assessment of coronary atherosclerotic plaque may be useful for risk stratification and treatment of atherosclerosis. MATERIALS AND METHODS: We studied 47 patients to investigate the accuracy of coronary plaque volume measurement acquired with 64-slice multislice computed tomography (MSCT), using newly developed quantification software, when compared with quantitative intracoronary ultrasound (QCU). Quantitative MSCT coronary angiography (QMSCT-CA) was performed to determine plaque volume for a matched region of interest (regional plaque burden) and in significant plaque defined as a plaque with > or =50% area obstruction in QCU, and compared with QCU. Dataset with image blurring and heavy calcification were excluded from analysis. RESULTS: In 100 comparable regions of interest, regional plaque burden was highly correlated (coefficient r = 0.96; P < 0.001) between QCU and QMSCT-CA, but QMSCT-CA overestimated the plaque burden by a mean difference of 7 +/- 33 mm3 (P = 0.03). In 76 significant plaques detected within the regions of interest, plaque volume determined by QMSCT-CA was highly correlated (r = 0.98; P < 0.001) with a slight underestimation of 2 +/- 17 mm3 (P = not significant) when compared with QCU. Calcified and mixed plaque volume was slightly overestimated by 4 +/- 19 mm3 (P = ns) and noncalcified plaque volume was significantly underestimated by 9 +/- 11 mm3 (P < 0.001) with QMSCT-CA. Overall, the limits of agreement for plaque burden/volume measurement between QCU and QMSCT-CA were relatively large. Reproducibility for the measurements of regional plaque burden with QMSCT-CA was good, with a mean intraobserver and interobserver variability of 0% +/- 16% and 4% +/- 24%, respectively. CONCLUSIONS: Quantification of coronary plaque within selected proximal or middle coronary segments without image blurring and heavy calcification with 64-slice CT was moderately accurate with respect to intravascular ultrasound and demonstrated good reproducibility. Further improvement in CT resolution is required for more reliable measurement of coronary plaques using quantification software.     

胰腺癌螺旋CT动态增强扫描征象的探讨

目的 :对胰腺癌螺旋CT动态增强扫描征象进行探讨。方法 :病理证实胰腺癌 37例 ,胰头癌 2 8例 ,胰体癌 5例 ,胰尾癌 4例。其中男 30例 ,女 7例。给予高分辨率螺旋CT动态增强扫描。结果 :胰腺癌主要征象 :胰腺肿块 ,在动脉期 (胰腺期 )表现为明显的低密度灶 ,胰腺肿块低密度灶与正常胰腺组织密度差有显著差异。其他征象 :胰管和胆管扩张 ;胰周脂肪间隙模糊 ;胰周血管变形和周围淋巴结肿大等。结论 :螺旋CT动态增强扫描对检出胰腺癌是非常有效的方法。     

非小细胞肺癌精确放疗中三种CT扫描方法的研究

目的 比较自主呼吸控制(ABC)、自由呼吸(FB)状态下慢速CT扫描(SS)和常规轴位扫描在周围型非小细胞肺癌(NSCLC)精确放疗中减小放射性肺损伤方面的作用差异。方法 10例周围型NSCLC患者在适形放疗定位时分别采集3种CT图像:1FB时常规轴位扫描;2ABC螺旋CT快速扫描;3FB时慢速CT扫描。将3套图像传输至计划系统,分别制定3个适形放疗计划,比较3个计划的大体肿瘤靶区(GTV)、临床靶区(CTV)、计划靶区(PTV)、受照剂量>20 Gy的正常肺组织占全肺体积的百分比(V₂₀)及全肺平均受照剂量(D_mean)。结果 3个计划的GTV、CTV体积以慢速扫描似乎最大,ABC计划似乎最小,但差异无统计学意义(F=1.513,P=0.238;F=1.376,P=0.270);FB常规轴位计划的PTV体积最大,且分别与另2个计划间差异有统计学意义(F=26.148,P=0.000);V₂₀、D_mean在FB常规轴位计划均最大,且FB计划和另2个计划间差异有统计学意义(F=7.623,P=0.002;F=18.217,P=0.000)。结论 相对于FB状态,使用ABC或慢速CT扫描可有效减少周围型NSCLC精确放疗中正常组织的受照体积和剂量,减小放射性肺损伤的发生率。