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1.
Objective To evaluate the respiration-induced target volume motion in 3D-CRT for mid-thoracic esophageal carcinoma in order to guide the radiation oncologist to choose the expansion margin for ITV.Methods Ten patients with mid-thoracic esophageal carcinoma were scanned by multi-spiral CT simulator respectively in free breathing(FB),breath.hold after normal inspiration and expiration(IBH and EBH)with the same scanning range.Then the CT images of three series were transfefred to the treatment planning system.The target volume was outlined following the same standard.The motion of the center point of GTV,the center point of each slice of GTV and the edge of the GTV in selected slice were measured respectively to obtain the comprehensive value of GTV motion。in order to find the appropriate IM value according to the 95%confidence interval of the GTV motion.Results ①The GTV motion between IBH and EBH was(0.19±0.16)cm in the left.right direction,(0.54±0.19)cm in the cranial and caudal irection.and(0.16±0.14)cm in anterior.posterior directions for the center of GTV,.For the center point of each slice of GTV.they ere(0.19±0.15)cm,(0.54±0.16)cm,(0.16±0.13)cm in three directions above.respectively.For the edge of the GTV in selected slice.they were(0.26±0.19)cm,(0.54±0.18)cm,(0.24±0.19)cm,respectively.The comprehensive value of GTV motion between IBH and EBH was(0.23±0.17)cm,(0.54±0.17)cm,(0.21±0.17)cm.respectively.The 95%confidence interval was 0.21-0.25 cm.0.53-0.56 cm and 0.19-0.22 cm in three directions.②The direction of GTV motion:No motion was noticed in 8.2%.while 73.3%to the right side and 18.5%to the left side in the left-right direction when IBH were compared with EBH.100%were moved to caudal in the the cranial and caudal direction[(0.54±0.17)cm].In the anterior-posterior direction,no motion was noticed in 8.2%,while 16.6%to the posterior and 75.2%to the anterior when IBH were compared with EBH.③The GTV motion was correlated with the vafiance of 1ung volumes in IBH-EBH(r=0.683,P=0.032)and not with GTV volume and length.Conclusions Respiration can induce target volume motion in 3 DCRT for mid-thoracic esophageal carcinoma.Compared to EBH.the GTV tends to move to the caudal,the anterior and the ight side in IBH.  相似文献   

2.
Objective To determine the effects of dose reduction on multi-slice spiral CT(MSCT) of neonatal head and assess the lowest possible radiation for acceptable clinical images.Methods Fifty-seven newborns suspected intracranial hemorrhage were entered into the study and underwent MSCT scans.Original images at three anatomic levels (posterior fossa, basal ganglia, centrum semiovale) were collected and synthetic noise was added so as to simulate dose reductions of 25%, 40%, 50% and 70%, respectively by using the noise addition tool.A total of 855 image data sets were obtained for the 57 patients.Original and simulated dose-reduction scan images were analyzed.Image noise and image quality were assessed by two independent experienced pediatric radiologists using diagnostic acceptability score, subjective image noise score on a 5-peint scale and objective noise index.Image noise was measured by respectively placing region of interest (ROI) at cerebellum, thalamus and corona radiata of 3 different slices.And the noise index and mean value was calculated.The degree of inter-observer concordance was determined by Kappa statistical analysis.The Spearman statistical correlations between the noise index and diagnostic acceptability score were performed.Results On the images of original dose and simulated dose reductions of 25%, 40%, 50% and 70%, the diagnostic acceptability was 4.47±0.51, 3.96±0.33, 3.21±0.45, 2.92±0.32, and 1.85±0.57, respectively,the subjective image scores were 1.62±0.48, 1.99±0.48, 2.76±0.81, 3.19±0.67, and 4.27±0.54, respectively, the noise index were 1.90±0.19, 2.17±0.20.2.44± 0.25, 2.68±0.28, and 3.37±0.39, respectively.The two radiologists had good intembserver agreement for diagnostic acceptability (K=0.860, P=0.017) and for image noise scoff ng (K=0.630, P=0.022).There was significant statistical correlation between image noise index and diagnostic acceptability (r= 0.826,P=0.001).At 40% dose reduction to the standard protocol, the noise index was 2.44 and the image quality score was 3.21 which were considered clinically acceptable.Conclusion The study revealed that acceptable imagos could be obtained with mean noise index of 2.44 and 40% dose reduction.  相似文献   

3.
Objective To determine the effects of dose reduction on multi-slice spiral CT(MSCT) of neonatal head and assess the lowest possible radiation for acceptable clinical images.Methods Fifty-seven newborns suspected intracranial hemorrhage were entered into the study and underwent MSCT scans.Original images at three anatomic levels (posterior fossa, basal ganglia, centrum semiovale) were collected and synthetic noise was added so as to simulate dose reductions of 25%, 40%, 50% and 70%, respectively by using the noise addition tool.A total of 855 image data sets were obtained for the 57 patients.Original and simulated dose-reduction scan images were analyzed.Image noise and image quality were assessed by two independent experienced pediatric radiologists using diagnostic acceptability score, subjective image noise score on a 5-peint scale and objective noise index.Image noise was measured by respectively placing region of interest (ROI) at cerebellum, thalamus and corona radiata of 3 different slices.And the noise index and mean value was calculated.The degree of inter-observer concordance was determined by Kappa statistical analysis.The Spearman statistical correlations between the noise index and diagnostic acceptability score were performed.Results On the images of original dose and simulated dose reductions of 25%, 40%, 50% and 70%, the diagnostic acceptability was 4.47±0.51, 3.96±0.33, 3.21±0.45, 2.92±0.32, and 1.85±0.57, respectively,the subjective image scores were 1.62±0.48, 1.99±0.48, 2.76±0.81, 3.19±0.67, and 4.27±0.54, respectively, the noise index were 1.90±0.19, 2.17±0.20.2.44± 0.25, 2.68±0.28, and 3.37±0.39, respectively.The two radiologists had good intembserver agreement for diagnostic acceptability (K=0.860, P=0.017) and for image noise scoff ng (K=0.630, P=0.022).There was significant statistical correlation between image noise index and diagnostic acceptability (r= 0.826,P=0.001).At 40% dose reduction to the standard protocol, the noise index was 2.44 and the image quality score was 3.21 which were considered clinically acceptable.Conclusion The study revealed that acceptable imagos could be obtained with mean noise index of 2.44 and 40% dose reduction.  相似文献   

4.
Objective To determine the effects of dose reduction on multi-slice spiral CT(MSCT) of neonatal head and assess the lowest possible radiation for acceptable clinical images.Methods Fifty-seven newborns suspected intracranial hemorrhage were entered into the study and underwent MSCT scans.Original images at three anatomic levels (posterior fossa, basal ganglia, centrum semiovale) were collected and synthetic noise was added so as to simulate dose reductions of 25%, 40%, 50% and 70%, respectively by using the noise addition tool.A total of 855 image data sets were obtained for the 57 patients.Original and simulated dose-reduction scan images were analyzed.Image noise and image quality were assessed by two independent experienced pediatric radiologists using diagnostic acceptability score, subjective image noise score on a 5-peint scale and objective noise index.Image noise was measured by respectively placing region of interest (ROI) at cerebellum, thalamus and corona radiata of 3 different slices.And the noise index and mean value was calculated.The degree of inter-observer concordance was determined by Kappa statistical analysis.The Spearman statistical correlations between the noise index and diagnostic acceptability score were performed.Results On the images of original dose and simulated dose reductions of 25%, 40%, 50% and 70%, the diagnostic acceptability was 4.47±0.51, 3.96±0.33, 3.21±0.45, 2.92±0.32, and 1.85±0.57, respectively,the subjective image scores were 1.62±0.48, 1.99±0.48, 2.76±0.81, 3.19±0.67, and 4.27±0.54, respectively, the noise index were 1.90±0.19, 2.17±0.20.2.44± 0.25, 2.68±0.28, and 3.37±0.39, respectively.The two radiologists had good intembserver agreement for diagnostic acceptability (K=0.860, P=0.017) and for image noise scoff ng (K=0.630, P=0.022).There was significant statistical correlation between image noise index and diagnostic acceptability (r= 0.826,P=0.001).At 40% dose reduction to the standard protocol, the noise index was 2.44 and the image quality score was 3.21 which were considered clinically acceptable.Conclusion The study revealed that acceptable imagos could be obtained with mean noise index of 2.44 and 40% dose reduction.  相似文献   

5.
Objective To measure the volume of hippoeampal formation(HPF) in healthy Chinese Han adults and provide database for researching on a variety of diseases associated with alteration of hippocampal structure. Methods This is a clinical multi-center study. One thousand Chinese healthy volunteers (age range = 18 to 70) recruited from 15 hospitals were divided into 5 groups, i. e. , Group A (age range = 18 to 30), B (age range =31 to40), C (age range =41 to 50), D (age range=51 to 60),and E (age range =61 to 70). Each group contained 100 males and 100 females. All of the volunteers were scanned by MR using T1 weighted three-dimensional magnetization prepared rapid acquisition gradient echo sequence. The margin of HPF were outlined manually for each side. Using multiple linear regression,relationships between hippocampal volume and sex, age, weight and height were analyzed respectively.Independent two sample t test was used to study the differences between male and female and between lcft and right. The differences of hippoeampal volume among age groups were analyzed by ANOVA. Results Hippocampal volume for left and right side were (4752 ± 659) and (5032 ± 660) mm3 respectively. The volume of HPF is significant correlated with gender and age, but without relevance to height and weight ( left and right r = 0. 283,0. 311, F = 30. 127,37. 050 ,P < 0. 01 ). The volumes of left and right hippocampus were (4897 ± 670), (5192 ± 667)mm3 respectively for men, and (4647 ± 624) and (4904 ± 630) mm3 for women. The right hippocampal volume was larger than the left ( t = 7. 030,6. 696, P < 0. 05 ). On both sides, men have larger hippocampus than that of women ( t = 6. 586,7. 326, P < 0. 01 ). The volumes of the left hippocampus among the five age groups in the male were (4981 ± 684), ( 5003 ± 609 ), (4976 ± 657 ),(4841 ± 631 ), (4631 ± 681 ) mm3 respectively, while the volumes of the right hippoeampus were (5340 ±647) ,(5276 ±582), (5264 ±620), (5133 ±661 ), (4894 ±699) mm3 respectively. Among age groups,the differences were statistically significant ( left and right F = 5. 737,7. 607, P < 0. 01 ). For male, there was significant difference of bilateral hippoeampus between the 18-30, 31-40, 41-50 years group and 61-70 years group ( P < 0. 05 ) and there was no significant difference among the other groups ( P > 0. 05 ).There was no significant difference of hippocampal among different groups in women (P > 0. 05 ).Conclusions With high-resolution MRI, the volume of the HPF was accurately measured, so as to provide the basic data for research of the hippocampus-related disease.  相似文献   

6.
Objective To explore the normal range of the volume of frontal lobe in Chinese adults of the Han nationality and provide morphological data for the construction of database for Chinese Standard Brain. Methods This is a clinical multi-center study. Two hundred Chinese healthy volunteers (age range= 18 to 70) recruited from 16 hospitals were divided into 5 groups, i. e. , age range from 18 to 30, age range from 31 to 40, age range from 41 to 50, age range from 51 to 60, and age range from 61 to 70. Each group contained 20 males and 20 females. All of the volunteers were scanned by MR using T1 weighted threedimensional magnetization prepared rapid acquisition gradient echo sequence. We used the manual method to trace the region of interest and measured the left and right frontal lobe volumes separately. All the data were analyzed with SPSS (version 13.0). The sex differences in the frontal lobe volumes were analyzed by independent-samples t test, and the side differences were analyzed by paired-samples t test. Correlation and regression analysis was used between the age and the frontal lobe volumes. Results In 200 healthy Chinese Han volunteers, the total frontal lobe volumes was (563 ± 73) cm3. For male, the volumes of the left and the right frontal lobe were (288±42) cm3 and (292 ±41 ) cm3 ,respectively. The volumes of the left and right frontal lobe in 100 women were (273 ±30) cm3 and (274 ± 30) cm3 respectively. The differences of sex (t = 3. 334, P < 0. 05 ) and side ( t = - 3.09, P < 0. 05 ) in the total frontal lobe volumes reach significant. There was no significant differences in women ( t = - 1. 304, P > 0. 05 ). There were negative correlations between the frontal lobe volumes and age in men and women ( r = - 0. 586, - 0. 498, P <0. 01 ). Conclusions The total frontal lobe volume of men was larger than that of women. The volume of the right frontal lobe was larger than the left frontal lobe in men, and the asymmetries didn't exist in women.The total frontal lobe volumes were both shrinking with age in men and women, which was more rapid in men than in women.  相似文献   

7.
Objective To explore the normal range of the volume of frontal lobe in Chinese adults of the Han nationality and provide morphological data for the construction of database for Chinese Standard Brain. Methods This is a clinical multi-center study. Two hundred Chinese healthy volunteers (age range= 18 to 70) recruited from 16 hospitals were divided into 5 groups, i. e. , age range from 18 to 30, age range from 31 to 40, age range from 41 to 50, age range from 51 to 60, and age range from 61 to 70. Each group contained 20 males and 20 females. All of the volunteers were scanned by MR using T1 weighted threedimensional magnetization prepared rapid acquisition gradient echo sequence. We used the manual method to trace the region of interest and measured the left and right frontal lobe volumes separately. All the data were analyzed with SPSS (version 13.0). The sex differences in the frontal lobe volumes were analyzed by independent-samples t test, and the side differences were analyzed by paired-samples t test. Correlation and regression analysis was used between the age and the frontal lobe volumes. Results In 200 healthy Chinese Han volunteers, the total frontal lobe volumes was (563 ± 73) cm3. For male, the volumes of the left and the right frontal lobe were (288±42) cm3 and (292 ±41 ) cm3 ,respectively. The volumes of the left and right frontal lobe in 100 women were (273 ±30) cm3 and (274 ± 30) cm3 respectively. The differences of sex (t = 3. 334, P < 0. 05 ) and side ( t = - 3.09, P < 0. 05 ) in the total frontal lobe volumes reach significant. There was no significant differences in women ( t = - 1. 304, P > 0. 05 ). There were negative correlations between the frontal lobe volumes and age in men and women ( r = - 0. 586, - 0. 498, P <0. 01 ). Conclusions The total frontal lobe volume of men was larger than that of women. The volume of the right frontal lobe was larger than the left frontal lobe in men, and the asymmetries didn't exist in women.The total frontal lobe volumes were both shrinking with age in men and women, which was more rapid in men than in women.  相似文献   

8.
Objective To evaluate the value of reducing radiation dose with ECG-pulsing and image quality in 64-row multi-alice CT coronary angiography.Methods Fifty-nine consecutive patients whose heart rates were less than 80 beat per minute and cardiac rhythm was regular were randomly divided into two groups from October 26, 2007 to March 12, 2008.Conventional technique of CT coronary angiography was employed in group 1, while ECG-pulsing technique was applied in group 2.CT dose index volume (CTDIvol) and dose length product (DLP) were obtained automatically, and then the corresponding effective dose (ED) were calculated.The quality scores were performed on obtained imaging by using double blind method.Student t-test was applied in the comparison of value of CTDIvol, value of ED and quality of imagiugbetween two groups.Results The value of CTDIvol was (70.0±1.1) and (39.0±2.7) mGy, the value of ED was (16.8±2.0) and (9.5±1.7) rosy in group 1 and group 2, respectively, which reached statistically significant differences between the groups(t=57.675,15.346 ,P <0.01, respectively). The quality scores of coronary images were 3.8±0.2 and 3.8±0.1 in the groups, which did not reach the statistical significance (t=-0.222, P 0.05).Conclusions The proper application of ECG-Pulsing technology in 64-slice spiral CT coronary angiography can reduce radiation dose significantly while having no influence on the quality of the imaging.  相似文献   

9.
Objective To investigate the effect of slice orientation on the popliteomeniscal fasciculi (PMF) MR imaging and its normal MRI appearances. Methods Volumetric MRI data of 40 knees of healthy volunteers were acquired using an isotropic 3D turbo spin echo (TSE) MR sequence. The posterior tangential line to both femoral condyles was used as the reference line, and the long axis sectional images of the popliteal hiatus region were reformatted at 0°, 15°, 30°, 45°, 60°, 75° and 90° to the reference line. The MRI appearances of the PMF were scored respectively and classified. The final scores of the PMF at each slice angle were statistically analyzed by a repeated measure ANOVA. Results At 0°, 15°, 30°, 45°, 60°, 75° and 90° slice angles: scores of the anteroinferior fasciculi were (1.7±0.7), (1.8±0.6), (1.9±0.6), (2.0±0.7), (1.9±0.7), (1.8±0.8) and (1.0±0.5),respectively. Scores of the posterosuperior fasciculi were (1.5±0.7), (1.9±0.7), (2.1±0.6), (2.2±0.6),(2.2±0.6), (2.0±0.8) and (1.7±0.8), respectively. There were statistically significant differences in the average scores at each slice angle for both anteroinferior fasciculi (F = 29.744, P = 0.000) and posterosuperior fasciculi (F = 19.770,P =0.000). The anteroinferior fasciculi and the posterosuperior fasciculi had highest average scores at the angle of 45°. The percentage of type A, B and C of anteroinferior fascicali were 20.0% (8/40), 75.0% (30/40) and 5.0% (2/40), respectively. The percentage of type A, B and C of posterosuperior fasciculi were 37.5% (15/40) ,62.5% (25/40) and 0% (0/40) ,respectively. Conclusion The anteroinferior fasciculi and the posterosuperior fasciculi can be well depicted at the angle of 45° slice orientation.  相似文献   

10.
目的 测量食管胸中段癌三维适形放疗中因呼吸运动而导致的靶区移位大小,为临床医师选择食管胸中段癌靶区外扩范围提供参考。方法 对10例食管胸中段癌患者行三维适形放疗定位时,分别于自由呼吸(FB)、自由吸气末屏气(IBH)及自由呼气末屏气(EBH)3个时相行相同范围的CT定位扫描。3套图像传输到计划系统并按照相同标准进行靶区的勾画。测量3种不同呼吸状态之间的大体肿瘤靶区(GTV)中心点移位、GTV每层中心点移位、感兴趣层面的GTV边缘形变移位,得到包含全部数值的综合值。并根据GTV移位的95%置信区间推断合适的内边界(IM)值。结果 1测量GTV中心点为左右方向(0.19±0.16)cm,头脚方向(0.54±0.19)cm,前后方向(0.16±0.14)cm;每层中心点分别为(0.19±0.15)cm、(0.54±0.16)cm和(0.16±0.13)cm;边缘分别为(0.26±0.19)cm、(0.54±0.18)cm和(0.24±0.19)cm;各方向含全部数值的综合值分别为(0.23±0.17)cm、(0.54±0.17)cm和(0.21±0.17)cm。其95%置信区间,左右、头脚和前后方向分别为0.21~0.25 cm、 0.53~0.56 cm和0.19~0.22 cm。2以EBH为基准,在IBH时左右方向,未发生移位的占8.2%,向右移位的占73.3%,向左移位的占18.5%;在头脚方向均向脚侧移位[(0.54±0.17) cm];在前后方向,未发生移位的占8.2%,向后移位的占16.6%,向前移位的占75.2%。3GTV移位与IBH-EBH之间双肺体积变化值呈正相关(r=0.683,P=0.032),与GTV体积及长度均无相关。结论 在食管胸中段癌的三维适形放疗中,呼吸运动可导致GTV移位,IBH较EBH时趋于向脚侧、向前、向右移位。  相似文献   

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