囊肿假性强化的体外实验及临床研究
发布时间：2018-09-17 11:42
【摘要】：第一部分不同扫描条件对囊肿假性强化的影响 目的：通过扫描肾脏的水模和模拟肾囊肿的不同直径的试管，验证假性强化的存在，并评估背景浓度、病变直径和容积CT剂量指数三种因素可能产生的影响。 方法：肾囊肿假性强化的研究使用长径约100cm×31.5cm的圆筒作为模拟人体的水模。7.0cm×16cm的塑料水杯模拟肾脏，3只不同直径的塑料试管模拟囊肿，其内均装满蒸馏水，水杯内先后装满10%葡萄糖液及一定浓度的含碘溶液，分别模拟平扫（30HU）、中等强化（90HU、125HU、180HU）及最大强化程度（240HU）的CT值。含碘剂的容器放入体模中心的底部，模拟脊柱。将双源CT校机后行腹部常规扫描模式，根据扫描条件分成三组，A组管电压为120KV，管电流为119mAs、CTDIvol为8.04mGy；B组管电压为120KV，管电流178mAs，CTDIvol为12.03mGy；C组管电压120KV，管电流297mAs，CTDIvol为20.08mGy。重建层厚均为1mm。以CT差值10HU为临界值，评估各个背景浓度下囊肿有无假性强化。 结果：A组仅在240HU背景浓度下出现了假性强化，且直径6mm的囊肿最显著，为21HU。其余背景浓度下差值均小于10HU。B组10mm和6mm的囊肿在180HU和240HU背景下均出现假性强化，差值最大为240HU6mm的囊肿，为20.4HU。C组仅直径6mm的囊肿在125HU和240HU背景浓度下有假性强化，且240HU背景下差值最大为12.7HU。背景浓度（F=17.587，p=0.0004）和直径（F=4.214，P=0.023）与假性强化有关。背景浓度越高，直径越小，假性强化越明显。从8mGy到20mGy，假性强化值分别为21HU，20.4HU及12.7HU，因此随着管电流的增大，CTDIvol的增加，假性强化值越来越小，但是各组中，不同背景浓度及不同直径的囊肿假性强化出现的概率没有显著的规律。 结论：囊肿的假性强化是客观存在的现象，背景浓度和囊肿直径是影响假性强化的重要因素，且背景浓度越高，囊肿直径越小，假性强化程度越大。常规扫描中假性强化的出现具有不确定性。 第二部分迭代重建算法对图像质量和假性强化的影响 目的：通过迭代重建算法，评估其对图像质量及假性强化的影响。 方法：模型的制备同第一部分。将双源CT校机后行腹部常规扫描模式，管电压120kv，管电流178mAs，CTDIvol=12.03mGy，SAFIRE第3滤波强度。以10HU为临界值，分析各背景浓度囊肿的CT差值，认为大于10HU为囊肿有假性强化，并分析添加SAFIRE前后假性强化程度的变化及噪声的差异。 结果：模拟肾囊肿测得的CT值范围是-3.5HU～17.4HU。不同直径的囊肿均出现了CT值大于10HU的情况，尤其在240HU背景浓度下，假性强化明显，且假性强化率达75%，表明随着背景浓度的提高，直径越小，假性强化值越大。差值最大出现在240HU背景下的6mm囊肿，为20.9HU。利用SAFIRE重建后，假性强化的程度与常规重建方法相比，没有统计学意义，说明迭代重建技术SAFIRE不会影响假性强化的程度。但它会使噪声明显减低，下降最明显的由之前的24.3下降到16.4，下降了33%。但总体看来，不同背景浓度其噪声下降的程度没有显著的规律。 结论：迭代重建算法SAFIRE可以提高图像质量，使噪声明显减低，但对消除假性强化及强化程度无显著作用。 第三部分能谱CT对囊肿假性强化的影响 目的：通过双能扫描所获得的CT值，评估双能融合图像及单能量图像对假性强化的影响。 方法：模型的制备同第一部分。将双源CT校机后进行扫描，采用腹部双能扫描模式，根据管电压不同分为两组，A组管电压80-sn140kv，CTDIvol为11.87mGy；B组管电压100-sn140kv，CTDIvol为12.03mGy，重建层厚均为1mm。将扫描数据传入Dual energy软件中，间隔10kev在40-190kev单能量图像中进行重建，测量囊肿CT值，并将双能融合图像传入viewing中，测量囊肿CT值。以10HU为临界值，分析双能融合图像及单能量图像是否存在假性强化。 结果：单能量图像中，相同扫描条件下，70kev、80kev及90kev各期与平扫的CT差值均小于10HU，表明这三种能量水平的图像不存在假性强化。图像信噪比的高低不一，没有显著规律。70kev、80kev及90kev图像噪声在统计学上没有显著差异，P值均大于0.05，但80kev图像噪声最小。双能融合图像中，A、B两组各期与30HU背景浓度相比，CT差值均小于10HU，说明双能融合图像不存在假性强化。 结论：双能融合图像不存在假性强化，因此,双能CT可以消除假性强化。70kev、80kev及90kev图像均能消除假性强化，80kev图像噪声最小。第四部分肾囊肿假性强化：双源CT的临床研究 目的：搜集经超声、MR及CT多期扫描均诊断为单纯性肾囊肿的病例，回顾性地分析常规扫描或双能扫描所获得的CT值，评估能谱CT在临床研究中对囊肿假性强化的影响。 方法：所有患者行常规平扫后，经肘静脉团注碘海醇非离子型造影剂90ml，速率为3.0ml/s，采集25s皮质期(cortical phase)、70s皮髓质期(corticomedullary phase)图像，保存平扫及皮髓质期图像并进行研究。第一组行腹部常规扫描模式，共13例患者18例囊肿，根据重建层厚不同再分为A组平扫5mm层厚，B组静脉期5mm层厚，C组静脉期1mm层厚。第二组13例患者共17例肾囊肿平扫先行腹部常规扫描模式，注射造影剂70s后行腹部双能扫描模式。同样根据重建层厚分为D组平扫5mm，E组静脉期5mm和F组静脉期1.5mm。通过测量不同期相及重建层厚的囊肿的CT值，分别分析常规和双能扫描中，平扫和静脉期图像囊肿CT值的差异，以均数（HU）±标准差的方式表示。 结果：26例患者共测量了35例囊肿，直径最小为7.0mm，最大为48.9mm。一、二两组中，囊肿的大小无统计学差异（t=-0.114, P=0.910）。第一组的平均直径为15.8±0.95mm，其中10例囊肿位于肾实质内（B组有2例出现假性强化，最大差值为12.3HU； C组有3例出现假性强化，最大差值为11.4HU），3例囊肿小于50%突出于肾脏轮廓（B组有1例出现假性强化，差值为11.4HU； C组有1例有假性强化，差值为14.2HU），3例囊肿大于50%位于肾脏轮廓之外（均无假性强化，差值均小于10HU）。常规扫描B组（t=6.377, P=0.0003）和C组（t=5.641, P=0.0001）均出现了假性强化。第二组的平均直径为16.2mm±1.01，其中15例囊肿位于肾实质内（E组有1例有假性强化，差值为11.0HU；F组均未出现假性强化，最大差值为6.4HU）,2例囊肿大于50%位于肾实质外（E组仅1例出现假性强化，，差值为12.4HU。F组仍无假性强化，最大差值为4.8HU）。双能扫描E组（t=5.799, P=0.0001）有假性强化，F组（t=0.542, P=0.297）无假性强化。 结论：临床研究验证了囊肿假性强化的存在，双能CT薄层扫描可以去除假性强化现象。
[Abstract]:Part I the effect of different scanning conditions on pseudocyst enhancement of cysts.
Objective: To verify the presence of pseudoenhancement by scanning the water model of kidney and the test tubes with different diameters of simulated renal cyst, and to evaluate the possible effects of background concentration, diameter of lesion and volume CT dose index.
Methods: The pseudo-enhancement of renal cysts was studied by using a cylinder with a length of about 100 cm *31.5 cm as a plastic water cup to simulate human kidneys. Three plastic test tubes with different diameters were filled with distilled water. The water cup was filled with 10% glucose solution and iodine solution of a certain concentration, respectively, to simulate plain scan (3.0 cm *16 cm). CT values of 0 HU, moderate enhancement (90 HU, 125 HU, 180 HU) and maximum enhancement (240 HU) were measured. Containers containing iodine were placed at the bottom of the phantom center to simulate the spine. In group C, the tube voltage was 120 KV, the tube current was 297 mAs, and the CT DIvol was 20.08 mGy. The thickness of reconstructed slices was 1 mm. The CT difference of 10 HU was used as the critical value to evaluate whether the cysts had pseudoenhancement at various background concentrations.
Results: Pseudo-enhancement was found only at 240 HU background concentration in group A, and the cysts with a diameter of 6 mm were the most prominent at 21 HU. The difference between the other background concentrations was less than 10 HU. The background concentration (F = 17.587, P = 0.0004) and diameter (F = 4.214, P = 0.023) were related to false enhancement. The higher the background concentration, the smaller the diameter, the more obvious the false enhancement. From 8 mGy to 20 mGy, the false enhancement values were 21 HU, 20.4 HU and 12.7 HU, respectively. Therefore, with the increase of tube current, CTDIvol increased. With the increase of cyst size, the pseudo-enhancement value became smaller and smaller, but the probability of pseudo-enhancement of cysts with different background concentrations and diameters did not change significantly in each group.
Conclusion: Pseudo-enhancement of cyst is an objective phenomenon. Background concentration and cyst diameter are important factors affecting pseudo-enhancement. The higher the background concentration, the smaller the cyst diameter and the greater the degree of pseudo-enhancement.
The influence of the second part iterative reconstruction algorithm on image quality and false enhancement
Objective: To evaluate the effect of the iterative reconstruction algorithm on image quality and false enhancement.
Methods: The model was made in the same way as the first part. The dual-source CT was used in the abdominal scanning mode. The tube voltage was 120 kv, the tube current was 178 mAs, the CTDIvol=12.03 mGy, and the filtering intensity of SAFIRE was 3. The change of degree and the difference of noise.
Results: The range of CT values measured by simulated renal cysts was - 3.5HU to 17.4HU. The CT values of cysts with different diameters were greater than 10HU. Especially at 240HU background concentration, the pseudo-enhancement was obvious and the pseudo-enhancement rate was 75%. It showed that the smaller the diameter, the larger the pseudo-enhancement value. 6 mm cyst, 20.9 HU. After SAFIRE reconstruction, the degree of pseudo-enhancement was not statistically significant compared with the conventional reconstruction method, indicating that the iterative reconstruction technique SAFIRE would not affect the degree of pseudo-enhancement. But it would significantly reduce the noise, the most obvious reduction from 24.3 to 16.4, a 33% reduction. But overall, different backs. There is no significant regularity in the degree of noise reduction.
Conclusion: The iterative reconstruction algorithm SAFIRE can improve the image quality and reduce the noise, but has no significant effect on eliminating false enhancement and enhancement.
The third part is the effect of CT on pseudocyst enhancement.
Objective: To evaluate the effect of dual-energy fusion image and single-energy image on pseudo-enhancement by CT value obtained from dual-energy scanning.
Methods: The model was made in the same way as the first part. The dual-source CT was scanned after calibration and divided into two groups according to the tube voltage: group A tube voltage 80-sn140 kv, CTDIvol 11.87 mGy, group B tube voltage 100-sn140 kv, CTDIvol 12.03 mGy, and the reconstructed thickness was 1 mm. Kev was reconstructed in 40-190 keV single energy images, CT values of cysts were measured, and dual energy fusion images were transferred into viewing to measure CT values of cysts.
Results: Under the same scanning condition, the difference of CT between 70 kev, 80 keV and 90 keV phases and plain scan was less than 10 HU, indicating that there was no false enhancement in the three energy levels of images. But the noise of 80 keV image is the smallest. In the dual-energy fusion image, the difference of CT between A and B groups is less than 10 HU compared with the background concentration of 30 HU in each phase, which indicates that there is no false enhancement in the dual-energy fusion image.
Conclusion: Dual-energy CT can eliminate pseudo-enhancement. 70 kev, 80 keV and 90 keV images can eliminate pseudo-enhancement. 80 keV images have the least noise. Part IV: Clinical study of dual-energy CT: pseudo-enhancement of renal cyst
Objective: To collect cases of simple renal cyst diagnosed by ultrasonography, MR and CT multi-phase scanning, retrospectively analyze the CT value obtained by conventional scanning or dual-energy scanning, and evaluate the effect of energy-dispersive CT on pseudoenhancement of cyst in clinical research.
Methods: After routine plain scan, all patients were injected iohexol nonionic contrast agent 90 mL through the elbow vein at a rate of 3.0 ml/s. The cortical phase of 25 s and corticomedullary phase of 70 s were collected. The images of plain scan and corticomedullary phase were preserved and studied. According to the thickness of reconstructed slices, 17 cases of renal cysts in the second group underwent routine abdominal scanning, 70 s contrast medium was injected, and then abdominal dual-energy scanning. Phase 1.5mm. The CT values of cysts with different phases and thickness of reconstructed slices were measured, and the differences of CT values between plain and venous phases were analyzed in terms of mean (HU) + standard deviation.
Results: A total of 35 cysts were measured in 26 patients. The minimum diameter was 7.0 mm and the maximum was 48.9 mm. There was no significant difference in the size of cysts between the two groups (t = - 0.114, P = 0.910). The average diameter of cysts in the first group was 15.8 (+ 0.95 mm), of which 10 were located in the renal parenchyma (2 cases in group B had pseudoenhancement, the maximum difference was 12.3 HU; 3 cases in group C had pseudoenhancement). The maximum difference was 11.4 HU, and 3 cysts were less than 50% protruding from the contour of the kidney (1 case in group B, 11.4 HU; 1 case in group C, 14.2 HU; 3 cysts were more than 50% outside the contour of the kidney (all without false enhancement, the difference was less than 10 HU). Routine scan group B (t = 6.377, P = 0.0003) and group C (t = 0.0003) The second group had an average diameter of 16.2 mm (+ 1.01), of which 15 cysts were located in the renal parenchyma (1 case in group E had pseudo-enhancement with a difference of 11.0 HU; none in group F had pseudo-enhancement with a maximum difference of 6.4 HU), and 2 cysts were more than 50% outside the renal parenchyma (only 1 case in group E had pseudo-enhancement with a difference of 12.4 HU.F). There was no false enhancement in group E (t = 5.799, P = 0.0001) and no false enhancement in group F (t = 0.542, P = 0.297).
Conclusion: Clinical studies have confirmed the existence of pseudo-enhancement of cysts. Dual-energy CT thin-layer scanning can remove pseudo-enhancement.
【学位授予单位】：河北医科大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R816.7
本文编号：2245787
[Abstract]:Part I the effect of different scanning conditions on pseudocyst enhancement of cysts.
Objective: To verify the presence of pseudoenhancement by scanning the water model of kidney and the test tubes with different diameters of simulated renal cyst, and to evaluate the possible effects of background concentration, diameter of lesion and volume CT dose index.
Methods: The pseudo-enhancement of renal cysts was studied by using a cylinder with a length of about 100 cm *31.5 cm as a plastic water cup to simulate human kidneys. Three plastic test tubes with different diameters were filled with distilled water. The water cup was filled with 10% glucose solution and iodine solution of a certain concentration, respectively, to simulate plain scan (3.0 cm *16 cm). CT values of 0 HU, moderate enhancement (90 HU, 125 HU, 180 HU) and maximum enhancement (240 HU) were measured. Containers containing iodine were placed at the bottom of the phantom center to simulate the spine. In group C, the tube voltage was 120 KV, the tube current was 297 mAs, and the CT DIvol was 20.08 mGy. The thickness of reconstructed slices was 1 mm. The CT difference of 10 HU was used as the critical value to evaluate whether the cysts had pseudoenhancement at various background concentrations.
Results: Pseudo-enhancement was found only at 240 HU background concentration in group A, and the cysts with a diameter of 6 mm were the most prominent at 21 HU. The difference between the other background concentrations was less than 10 HU. The background concentration (F = 17.587, P = 0.0004) and diameter (F = 4.214, P = 0.023) were related to false enhancement. The higher the background concentration, the smaller the diameter, the more obvious the false enhancement. From 8 mGy to 20 mGy, the false enhancement values were 21 HU, 20.4 HU and 12.7 HU, respectively. Therefore, with the increase of tube current, CTDIvol increased. With the increase of cyst size, the pseudo-enhancement value became smaller and smaller, but the probability of pseudo-enhancement of cysts with different background concentrations and diameters did not change significantly in each group.
Conclusion: Pseudo-enhancement of cyst is an objective phenomenon. Background concentration and cyst diameter are important factors affecting pseudo-enhancement. The higher the background concentration, the smaller the cyst diameter and the greater the degree of pseudo-enhancement.
The influence of the second part iterative reconstruction algorithm on image quality and false enhancement
Objective: To evaluate the effect of the iterative reconstruction algorithm on image quality and false enhancement.
Methods: The model was made in the same way as the first part. The dual-source CT was used in the abdominal scanning mode. The tube voltage was 120 kv, the tube current was 178 mAs, the CTDIvol=12.03 mGy, and the filtering intensity of SAFIRE was 3. The change of degree and the difference of noise.
Results: The range of CT values measured by simulated renal cysts was - 3.5HU to 17.4HU. The CT values of cysts with different diameters were greater than 10HU. Especially at 240HU background concentration, the pseudo-enhancement was obvious and the pseudo-enhancement rate was 75%. It showed that the smaller the diameter, the larger the pseudo-enhancement value. 6 mm cyst, 20.9 HU. After SAFIRE reconstruction, the degree of pseudo-enhancement was not statistically significant compared with the conventional reconstruction method, indicating that the iterative reconstruction technique SAFIRE would not affect the degree of pseudo-enhancement. But it would significantly reduce the noise, the most obvious reduction from 24.3 to 16.4, a 33% reduction. But overall, different backs. There is no significant regularity in the degree of noise reduction.
Conclusion: The iterative reconstruction algorithm SAFIRE can improve the image quality and reduce the noise, but has no significant effect on eliminating false enhancement and enhancement.
The third part is the effect of CT on pseudocyst enhancement.
Objective: To evaluate the effect of dual-energy fusion image and single-energy image on pseudo-enhancement by CT value obtained from dual-energy scanning.
Methods: The model was made in the same way as the first part. The dual-source CT was scanned after calibration and divided into two groups according to the tube voltage: group A tube voltage 80-sn140 kv, CTDIvol 11.87 mGy, group B tube voltage 100-sn140 kv, CTDIvol 12.03 mGy, and the reconstructed thickness was 1 mm. Kev was reconstructed in 40-190 keV single energy images, CT values of cysts were measured, and dual energy fusion images were transferred into viewing to measure CT values of cysts.
Results: Under the same scanning condition, the difference of CT between 70 kev, 80 keV and 90 keV phases and plain scan was less than 10 HU, indicating that there was no false enhancement in the three energy levels of images. But the noise of 80 keV image is the smallest. In the dual-energy fusion image, the difference of CT between A and B groups is less than 10 HU compared with the background concentration of 30 HU in each phase, which indicates that there is no false enhancement in the dual-energy fusion image.
Conclusion: Dual-energy CT can eliminate pseudo-enhancement. 70 kev, 80 keV and 90 keV images can eliminate pseudo-enhancement. 80 keV images have the least noise. Part IV: Clinical study of dual-energy CT: pseudo-enhancement of renal cyst
Objective: To collect cases of simple renal cyst diagnosed by ultrasonography, MR and CT multi-phase scanning, retrospectively analyze the CT value obtained by conventional scanning or dual-energy scanning, and evaluate the effect of energy-dispersive CT on pseudoenhancement of cyst in clinical research.
Methods: After routine plain scan, all patients were injected iohexol nonionic contrast agent 90 mL through the elbow vein at a rate of 3.0 ml/s. The cortical phase of 25 s and corticomedullary phase of 70 s were collected. The images of plain scan and corticomedullary phase were preserved and studied. According to the thickness of reconstructed slices, 17 cases of renal cysts in the second group underwent routine abdominal scanning, 70 s contrast medium was injected, and then abdominal dual-energy scanning. Phase 1.5mm. The CT values of cysts with different phases and thickness of reconstructed slices were measured, and the differences of CT values between plain and venous phases were analyzed in terms of mean (HU) + standard deviation.
Results: A total of 35 cysts were measured in 26 patients. The minimum diameter was 7.0 mm and the maximum was 48.9 mm. There was no significant difference in the size of cysts between the two groups (t = - 0.114, P = 0.910). The average diameter of cysts in the first group was 15.8 (+ 0.95 mm), of which 10 were located in the renal parenchyma (2 cases in group B had pseudoenhancement, the maximum difference was 12.3 HU; 3 cases in group C had pseudoenhancement). The maximum difference was 11.4 HU, and 3 cysts were less than 50% protruding from the contour of the kidney (1 case in group B, 11.4 HU; 1 case in group C, 14.2 HU; 3 cysts were more than 50% outside the contour of the kidney (all without false enhancement, the difference was less than 10 HU). Routine scan group B (t = 6.377, P = 0.0003) and group C (t = 0.0003) The second group had an average diameter of 16.2 mm (+ 1.01), of which 15 cysts were located in the renal parenchyma (1 case in group E had pseudo-enhancement with a difference of 11.0 HU; none in group F had pseudo-enhancement with a maximum difference of 6.4 HU), and 2 cysts were more than 50% outside the renal parenchyma (only 1 case in group E had pseudo-enhancement with a difference of 12.4 HU.F). There was no false enhancement in group E (t = 5.799, P = 0.0001) and no false enhancement in group F (t = 0.542, P = 0.297).
Conclusion: Clinical studies have confirmed the existence of pseudo-enhancement of cysts. Dual-energy CT thin-layer scanning can remove pseudo-enhancement.
【学位授予单位】：河北医科大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R816.7
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