多層螺旋CT胸部掃描技術(shù)與圖像噪聲及病變檢出相關(guān)性研究
發(fā)布時間：2018-08-03 21:37
【摘要】：目的：探討胸部CT掃描參數(shù)變化與不同組織噪聲的相關(guān)性及圖像質(zhì)量影響的規(guī)律。方法：應(yīng)用GE BrightSpeed16層CT機(jī)以管電壓120kV，管電流300mA，螺距0.938為標(biāo)準(zhǔn)，每次掃描改變一種掃描參數(shù)，其它掃描參數(shù)不變，以不同管電壓（80、100、120、140kV）、管電流（80、100、120、180、240、300mA）及螺距（0.562、0.938、1.375、1.75）掃描仿真胸部體模，測量、記錄體模不同組織噪聲值（CT值標(biāo)準(zhǔn)差，SD），并進(jìn)行統(tǒng)計學(xué)分析。結(jié)果：肺組織不同管電壓組（80、100、120、140kV）的噪聲比較差異無統(tǒng)計學(xué)意義（F=0.966,P＞0.05），而胸壁軟組織、脊柱旁軟組織及主動脈噪聲80kV組與常規(guī)管電壓120kV組比較差異有統(tǒng)計學(xué)意義，P＜0.05。肺組織、脊柱旁軟組織及主動脈噪聲不同管電流組（80、100、120、180、240、300mA）差異均有統(tǒng)計學(xué)意義（肺組織F=3.28，P＜0.05、脊柱旁軟組織F=11.89，P＜0.05及主動脈F=196.67，P＜0.05）；肺、胸壁軟組織、脊柱旁軟組織及主動脈噪聲80mA組與常規(guī)管電流300mA組比較差異有統(tǒng)計學(xué)意義，P＜ 0.05；脊柱旁軟組織噪聲80mA組與常規(guī)管電流300mA組比較差異有統(tǒng)計學(xué)意義，P＜0.05。肺、胸壁軟組織、脊柱旁軟組織不同螺距組（0.562、0.938、1.35及1.75）噪聲差異無統(tǒng)計學(xué)意義（肺組織F=0.23,P＞0.05；胸壁軟組織F=1.53,P＞0.05；脊柱旁軟組織F=2.27,P＞0.05）；主動脈噪聲不同螺距組比較差異有統(tǒng)計學(xué)意義（F=9.68,P＜0.05）。結(jié)論：降低管電壓、管電流，增加螺距時，不同組織噪聲逐漸增高，但肺組織的噪聲增加不明顯，胸部低劑量掃描時能夠在保證肺組織圖像噪聲變化不大的同時降低輻射劑量。 目的：分析胸部低劑量CT圖像噪聲分布特點(diǎn)并優(yōu)化低劑量掃描參數(shù)。方法結(jié)果結(jié)論方法：利用圖像空間噪聲添加軟件計算中國人仿真胸部體模CT圖像（6組不同噪聲指數(shù)）噪聲值，分析預(yù)設(shè)噪聲指數(shù)與模擬噪聲值差異性。采用圖像空間噪聲添加軟件對20例志愿者在常規(guī)參數(shù)下掃描獲得的原始圖像（美國GE公司Brightspeed16排螺旋CT）進(jìn)行噪聲添加，，模擬出10、30、50、80、100、120、150、180及240mA9組胸部低劑量圖像，記錄每幅圖像模擬噪聲值，并對不同毫安組模擬噪聲值進(jìn)行統(tǒng)計學(xué)分析。結(jié)果：圖像噪聲添加法計算的模擬噪聲值與預(yù)設(shè)噪聲指數(shù)差異無統(tǒng)計學(xué)意義（P0.05）；胸部低劑量掃描時圖像模擬噪聲值隨著管電流降低不斷增加，當(dāng)管電流在10~50mA時噪聲降低顯著，80~300mA時噪聲值降低幅度變緩。80mA組與120mA組之間圖像噪聲差異無統(tǒng)計學(xué)意義（P0.05）。結(jié)論：圖像空間噪聲添加軟件可應(yīng)用于胸部低劑量CT圖像噪聲的評價研究。胸部低劑量CT檢查時采用管電流80~120mA時能夠保證圖像噪聲無明顯變化的同時又可以降低輻射劑量。 目的：利用置入肺結(jié)節(jié)和熱釋光劑量計(thermoluminescentdosimeters， TLD)的胸部體模，測量數(shù)字?jǐn)鄬尤诤?digitaltomosynthesis， DTS)技術(shù)及多層CT(multi-slice computertomography， MSCT)胸部掃描時不同組織器官的吸收劑量，評價種方法對肺結(jié)節(jié)的檢出率及輻射劑量水平。方法：采用DTS及MSCT分別掃描共置入45個模擬結(jié)節(jié)及TLD的胸部體模，記錄并儲存圖像，測量胸部主要組織器官的吸收劑量并計算有效劑量。由3名放射診斷醫(yī)師分別進(jìn)行閱片并記錄結(jié)節(jié)部位、大小及密度。采用Fisher確切概率法檢驗(yàn)與X2檢驗(yàn)，比較DTS與MSCT掃描對模擬結(jié)節(jié)檢出率的差別；兩種檢查方法器官吸收劑量的比較采用配對t檢驗(yàn)。結(jié)果：DTS與MSCT對肺結(jié)節(jié)檢出率為66.7%(30/45)和91.1%(41/45)，兩者差異有統(tǒng)計學(xué)意義（X2=8.073，P＜0.05)；對-650HU磨玻璃結(jié)節(jié)檢出率為93.3%和73.3%，兩者差異無統(tǒng)計學(xué)意義，(P＞0.05)；DTS對-800HU磨玻璃結(jié)節(jié)及直徑小于8mm磨玻璃結(jié)節(jié)檢出率為5/15(33.3%)和2/12(16.7%),MSCT檢出率為12/15(80%)和8/12(66.7%)。胸部DTS檢查各主要組織器官吸收劑量明顯低于MSCT,兩者差異有統(tǒng)計學(xué)意義(肺t=19.69，P＜0.05；胸椎t=30.01，P＜0.05；心臟t=16.33，P＜0.05；肝臟t=5.06，P＜0.05；、乳腺t=9.43，P＜0.05；甲狀腺t=8.05，P＜0.05)；DTS與MSCT胸部掃描的有效劑量分別為0.65mSv、7.71mSv。結(jié)論：DTS對于-650HU磨玻璃結(jié)節(jié)檢出率與MSCT相近，DTS對極低密度(-800HU)磨玻璃結(jié)節(jié)及直徑小于8mm磨玻璃結(jié)節(jié)檢出率低。肺胸部結(jié)節(jié)檢查時，DTS有效劑量低于MSCT，約為MSCT輻射劑量的8.41%。
[Abstract]:Objective: To investigate the correlation between the changes of the parameters of the chest CT scan and the noise of different tissues and the law of the influence of the image quality. Methods: using the GE BrightSpeed16 layer CT machine, the tube voltage 120kV, the tube current 300mA, the pitch 0.938 are the standard, and the scanning parameters are changed each time, the other scanning parameters are constant, and the different tube voltage (80100120140kV), Tube current (80100120180240300mA) and pitch (0.562,0.938,1.375,1.75) scanning simulation of chest body model, measurement, recording different tissue noise values (CT standard deviation, SD), and statistical analysis. Results: different tube voltage group (80100120140kV) of lung tissue (80100120140kV) has no statistically significant difference (F=0.966, P > 0.05), but the chest wall The difference between the soft tissue, the para spinal soft tissue and the aortic noise 80kV group was statistically significant compared with the conventional tube voltage 120kV group. The differences in P < 0.05. lung tissue, the paravertebral soft tissue and the aortic noise different tube current group (80100120180240300mA) were statistically significant (F= 3.28 in the lung tissue, P < 0.05, F=11.89 of the paravertebral soft tissue, P < 0.05). The aorta was F=196.67, P < 0.05); the lung, the soft tissue of the chest wall, the soft tissue of the spinal column and the 80mA group of the aortic noise were significantly different from that of the conventional tube current 300mA group, P
0.05, there were significant differences in the noise between the 80mA group and the routine tube current 300mA group. There was no significant difference between the P < 0.05. lung, the chest wall soft tissue and the different pitch groups (0.562,0.938,1.35 and 1.75) of the para soft tissue (0.562,0.938,1.35 and 1.75) (P > 0.05; the chest wall soft tissue F=1.53, P > 0.05; F=2.27, P in the para spinal soft tissue. > 0.05) and there was a significant difference between the different spiral distance groups of the aorta (F=9.68, P < 0.05). Conclusion: the noise of different tissues increases gradually when the tube voltage, the tube current and the pitch are increased, but the increase of the noise of the lung tissue is not obvious, and the low dose scanning of the chest can reduce the change of the image noise of the lung tissue at the same time. Shoot dose.
Objective: to analyze the noise distribution characteristics of low dose chest CT images and optimize the low dose scanning parameters. Method results: using image spatial noise adding software to calculate the noise values of Chinese human simulated chest CT images (6 groups of different noise indices), and analyze the difference between the preset noise index and the simulated noise value. Noise addition software was used to add noise to the original images (GE Brightspeed16 row spiral CT) of 20 volunteers, to simulate the low dose chest images of 10,30,50,80100120150180 and 240mA9 groups, to record the noise values of each image, and to make statistical analysis of the simulated noise values of the different MS group. Results: there is no significant difference between the simulated noise value calculated by the image noise addition method and the presupposed noise index (P0.05). The noise value of the image in the low dose chest increases with the decrease of the tube current, and the noise decreases significantly when the tube current is at 10~50mA. The reduction of noise value at 80~300mA slows down the map between the.80mA group and the 120mA group. There is no statistical significance (P0.05). Conclusion: the image spatial noise adding software can be applied to the evaluation of low dose CT image noise in the chest. When the chest low dose CT examination is used, the use of the tube current can ensure that the image noise has no obvious change while reducing the radiation dose.
Objective: to measure the absorbable dose of different tissues and organs in the chest scan of multi-layer CT (multi-slice computertomography, MSCT), and to evaluate the detection rate of the pulmonary nodules by using the digitaltomosynthesis (digitaltomosynthesis, DTS) technique and the chest scanning of the thermoluminescentdosimeters (TLD). Method: DTS and MSCT were used to scan and store 45 mock nodules and TLD models of chest body, recorded and stored images, measured the absorption dose of the main tissues and organs of the chest and calculated the effective dose. 3 radiologists performed the film and recorded the location, size and density of the nodules. The exact probability of Fisher was used. The difference between DTS and MSCT scan on the detection rate of simulated nodules was compared with the X2 test. The comparison of the two methods of organ absorption was compared with the paired t test. Results: the detection rate of DTS and MSCT for pulmonary nodules was 66.7% (30/45) and 91.1% (41/45), and the difference was statistically significant (X2=8.073, P < 0.05), and the detection of -650HU glass nodules was detected. The rate was 93.3% and 73.3%, the difference was not statistically significant (P > 0.05); the detection rate of DTS for -800HU grinding glass nodules and the diameter less than 8mm grinding glass nodules was 5/15 (33.3%) and 2/12 (16.7%), MSCT detection rate was 12/15 (80%) and 8/12 (66.7%). Chest DTS examination of the main tissues and organs absorption dose was significantly lower than MSCT, the difference was statistically significant ( Lung t=19.69, P < 0.05; thoracic vertebra t=30.01, P < 0.05; heart t=16.33, P < 0.05; liver t=5.06, P < 0.05; breast t=9.43, P < 0.05; t=8.05 thyroid gland, P < 0.05). The detection rate of ground-glass nodules and ground-glass nodules less than 8 mm in diameter was low. The effective dose of DTS was lower than that of MSCT, which was about 8.41% of the radiation dose of MSCT.
【學(xué)位授予單位】：重慶醫(yī)科大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2012
【分類號】：R816.4
本文編號：2163067
[Abstract]:Objective: To investigate the correlation between the changes of the parameters of the chest CT scan and the noise of different tissues and the law of the influence of the image quality. Methods: using the GE BrightSpeed16 layer CT machine, the tube voltage 120kV, the tube current 300mA, the pitch 0.938 are the standard, and the scanning parameters are changed each time, the other scanning parameters are constant, and the different tube voltage (80100120140kV), Tube current (80100120180240300mA) and pitch (0.562,0.938,1.375,1.75) scanning simulation of chest body model, measurement, recording different tissue noise values (CT standard deviation, SD), and statistical analysis. Results: different tube voltage group (80100120140kV) of lung tissue (80100120140kV) has no statistically significant difference (F=0.966, P > 0.05), but the chest wall The difference between the soft tissue, the para spinal soft tissue and the aortic noise 80kV group was statistically significant compared with the conventional tube voltage 120kV group. The differences in P < 0.05. lung tissue, the paravertebral soft tissue and the aortic noise different tube current group (80100120180240300mA) were statistically significant (F= 3.28 in the lung tissue, P < 0.05, F=11.89 of the paravertebral soft tissue, P < 0.05). The aorta was F=196.67, P < 0.05); the lung, the soft tissue of the chest wall, the soft tissue of the spinal column and the 80mA group of the aortic noise were significantly different from that of the conventional tube current 300mA group, P
0.05, there were significant differences in the noise between the 80mA group and the routine tube current 300mA group. There was no significant difference between the P < 0.05. lung, the chest wall soft tissue and the different pitch groups (0.562,0.938,1.35 and 1.75) of the para soft tissue (0.562,0.938,1.35 and 1.75) (P > 0.05; the chest wall soft tissue F=1.53, P > 0.05; F=2.27, P in the para spinal soft tissue. > 0.05) and there was a significant difference between the different spiral distance groups of the aorta (F=9.68, P < 0.05). Conclusion: the noise of different tissues increases gradually when the tube voltage, the tube current and the pitch are increased, but the increase of the noise of the lung tissue is not obvious, and the low dose scanning of the chest can reduce the change of the image noise of the lung tissue at the same time. Shoot dose.
Objective: to analyze the noise distribution characteristics of low dose chest CT images and optimize the low dose scanning parameters. Method results: using image spatial noise adding software to calculate the noise values of Chinese human simulated chest CT images (6 groups of different noise indices), and analyze the difference between the preset noise index and the simulated noise value. Noise addition software was used to add noise to the original images (GE Brightspeed16 row spiral CT) of 20 volunteers, to simulate the low dose chest images of 10,30,50,80100120150180 and 240mA9 groups, to record the noise values of each image, and to make statistical analysis of the simulated noise values of the different MS group. Results: there is no significant difference between the simulated noise value calculated by the image noise addition method and the presupposed noise index (P0.05). The noise value of the image in the low dose chest increases with the decrease of the tube current, and the noise decreases significantly when the tube current is at 10~50mA. The reduction of noise value at 80~300mA slows down the map between the.80mA group and the 120mA group. There is no statistical significance (P0.05). Conclusion: the image spatial noise adding software can be applied to the evaluation of low dose CT image noise in the chest. When the chest low dose CT examination is used, the use of the tube current can ensure that the image noise has no obvious change while reducing the radiation dose.
Objective: to measure the absorbable dose of different tissues and organs in the chest scan of multi-layer CT (multi-slice computertomography, MSCT), and to evaluate the detection rate of the pulmonary nodules by using the digitaltomosynthesis (digitaltomosynthesis, DTS) technique and the chest scanning of the thermoluminescentdosimeters (TLD). Method: DTS and MSCT were used to scan and store 45 mock nodules and TLD models of chest body, recorded and stored images, measured the absorption dose of the main tissues and organs of the chest and calculated the effective dose. 3 radiologists performed the film and recorded the location, size and density of the nodules. The exact probability of Fisher was used. The difference between DTS and MSCT scan on the detection rate of simulated nodules was compared with the X2 test. The comparison of the two methods of organ absorption was compared with the paired t test. Results: the detection rate of DTS and MSCT for pulmonary nodules was 66.7% (30/45) and 91.1% (41/45), and the difference was statistically significant (X2=8.073, P < 0.05), and the detection of -650HU glass nodules was detected. The rate was 93.3% and 73.3%, the difference was not statistically significant (P > 0.05); the detection rate of DTS for -800HU grinding glass nodules and the diameter less than 8mm grinding glass nodules was 5/15 (33.3%) and 2/12 (16.7%), MSCT detection rate was 12/15 (80%) and 8/12 (66.7%). Chest DTS examination of the main tissues and organs absorption dose was significantly lower than MSCT, the difference was statistically significant ( Lung t=19.69, P < 0.05; thoracic vertebra t=30.01, P < 0.05; heart t=16.33, P < 0.05; liver t=5.06, P < 0.05; breast t=9.43, P < 0.05; t=8.05 thyroid gland, P < 0.05). The detection rate of ground-glass nodules and ground-glass nodules less than 8 mm in diameter was low. The effective dose of DTS was lower than that of MSCT, which was about 8.41% of the radiation dose of MSCT.
【學(xué)位授予單位】：重慶醫(yī)科大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2012
【分類號】：R816.4
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