本文選題：雙能CT + 單能譜圖像　； 參考：《重慶醫(yī)科大學(xué)》2017年碩士論文

【摘要】：第一部分雙能CT單能譜成像檢測不同性質(zhì)孤立性肺結(jié)節(jié)的實驗研究目的:分析單能譜圖像與孤立性肺結(jié)節(jié)檢出率及其圖像質(zhì)量的關(guān)系。方法:采用男性胸部仿真體模,并隨機置入不同密度(-800HU、-650HU與100HU)及大小(3mm、5mm、8mm、10mm、12mm)的球形模擬肺結(jié)節(jié),使用西門子雙源炫速CT(SOMATOM definition flash)雙能量模式(80/140KV)對體模進行掃描,提取出不同能量水平的單能譜圖像后對每組圖像進行圖像質(zhì)量及檢出率分析。分組1:每種密度肺結(jié)節(jié)中各包含5種不同直徑肺結(jié)節(jié)各6枚,共計90枚;分組2:選取-650HU磨玻璃肺結(jié)節(jié),每種直徑肺結(jié)節(jié)各9枚,共計45枚。使用SPSS軟件進行統(tǒng)計分析,肺結(jié)節(jié)的噪聲、SNR、CNR采用ANOVA方差分析,若差異有統(tǒng)計學(xué)意義,則進一步進行兩兩對比(若方差齊則使用LSD檢驗,方差不齊使用Dunnett T3檢驗);肺結(jié)節(jié)檢出率的比較采用Fisher確切概率法。結(jié)果:-800HU、-650HU與100HU的模擬肺結(jié)節(jié)在不同單能譜圖像上噪聲、SNR及CNR的差異有統(tǒng)計學(xué)意義(P0.05),且通過繪制折線圖發(fā)現(xiàn)在70ke V圖像上,各密度肺結(jié)節(jié)的噪聲低而SNR、CNR最高;以70ke V為對照組,65ke V、75ke V與70ke V兩兩比較,相同密度肺結(jié)節(jié)圖像噪聲、SNR及CNR的差異無統(tǒng)計學(xué)意義(P0.05);在-650HU肺結(jié)節(jié)中,5種不同直徑的肺結(jié)節(jié)在每個單能量水平圖像上的噪聲、SNR及CNR的差異均無統(tǒng)計學(xué)意義(P0.05)。在60~140ke V圖像上-800HU、-650及100HU肺結(jié)節(jié)檢出率為100%,大于5mm的模擬肺結(jié)節(jié)在所有單能譜圖像上均檢出。在40和50ke V圖像上-800HU及3mm模擬肺結(jié)節(jié)檢出率低于60~140ke V(P0.05)。結(jié)論:胸部雙能CT孤立性肺結(jié)節(jié)成像時,70ke V時圖像的噪聲最小,其SNR與CNR最高;選擇60ke V以上單能譜圖像可提高孤立性肺結(jié)節(jié)的檢出率。第二部分雙能量CT非線性圖像融合技術(shù)對孤立性肺結(jié)節(jié)成像的可行性研究目的:探討雙能量CT非線性融合技術(shù)對孤立性肺結(jié)節(jié)成像的可行性,優(yōu)化各密度肺結(jié)節(jié)非線性融合參數(shù)。方法:采用男性胸部仿真體模,利用非離子型對比劑碘普羅胺注射液與生理鹽水混合模擬增強掃描后不同密度肺結(jié)節(jié)并置入胸部體模,分別使用西門子雙源炫速CT(SOMATOM definition flash)雙能模式(80/140k V)及單能120k V(兩者CTDI值一致)對體模進行掃描后重建出線性及非線性融合圖像后對圖像進行圖像質(zhì)量分析。結(jié)果:對于各不同CT值的模擬肺結(jié)節(jié),BC為0HU,BW為0~30HU時可獲得較高的CNR。不同CT值的模擬肺結(jié)節(jié)在非線性融合、線性融合及120k V圖像上的噪聲值及SNR差異有統(tǒng)計學(xué)意義(P0.05),CNR差異無統(tǒng)計學(xué)意義(P0.05)。其中各不同密度模擬肺結(jié)節(jié)在非線性融合優(yōu)化圖像的SNR顯著高于線性融合組及120k V組(P0.05);而圖像的噪聲在非線性融合優(yōu)化組低于線性融合組(P0.05)。結(jié)論:雙能量CT非線性融合優(yōu)化技術(shù)使CT增強掃描后肺結(jié)節(jié)的SNR明顯提高,可為更準確診斷孤立性肺結(jié)節(jié)提供幫助。
[Abstract]:The first part of the experimental study on the detection of solitary pulmonary nodules with dual energy CT single energy spectrum imaging objective: to analyze the relationship between single energy spectrum images and the detection rate and image quality of solitary pulmonary nodules. Methods: the male chest phantom was used, and the spherical simulated pulmonary nodules with different densities of Hu-800HU-650HU and 100HUU) and size of 3mm / 5mm / 8mm / 10mm / 12mm) were randomly placed. The models were scanned by Siemens dual-source CT(SOMATOM definition flash-mode (80 / 140KV). After extracting single energy spectrum images with different energy levels, the image quality and detection rate of each group of images were analyzed. Group 1: there were 6 pulmonary nodules with 5 different diameters in each density and 90 nodules in different diameters. Group 2 was divided into two groups: -650 Hu milled glass-shaped pulmonary nodules, each with 9 pulmonary nodules, with a total of 45. SPSS software was used for statistical analysis. The noise of pulmonary nodules was analyzed by ANOVA ANOVA. If the difference was statistically significant, further comparison was made (if the variance was homogeneous, LSD test was used. Dunnett T 3 test was used for variance heterogeneity, and Fisher exact probability method was used to compare the detection rate of pulmonary nodules. Results there was significant difference in noise SNR and CNR between the simulated pulmonary nodule between the two groups on different single energy spectrum images (P0.05A). It was found that on the 70ke V image, the noisiness of each density pulmonary nodule was lower and the SNRN was the highest. 70ke V was compared with 70ke V in the control group. There was no significant difference in noise-SNR and CNR in the same density pulmonary nodule images (P 0.05), but there was no significant difference in the noise of 5 lung nodules with different diameters on each single energy level image (P 0.05). On 60~140ke V images, the detectable rate of pulmonary nodules of -800 HU-650 and 100HU was 100. The simulated pulmonary nodules larger than 5mm were detected on all single energy spectrum images. The detectable rate of -800 Hu and 3mm simulated pulmonary nodules on 40 and 50ke V images was lower than that on 60~140ke V V (P 0.05). Conclusion: the SNR and CNR of solitary pulmonary nodules were the least and the SNR and CNR were the highest at 70ke V, and the detection rate of solitary pulmonary nodules could be improved by selecting single energy spectrum images above 60ke V. The second part: feasibility study of dual energy CT nonlinear image fusion technique for solitary pulmonary nodule imaging objective: to explore the feasibility of dual energy CT nonlinear fusion technique in solitary pulmonary nodule imaging. The nonlinear fusion parameters of lung nodules with different densities were optimized. Methods: male chest phantom was used to simulate the pulmonary nodules of different density after contrast injection of non-ionic contrast agent iopramide and normal saline. Siemens dual-source CT(SOMATOM definition flash-two-energy mode (80 / 140kV) and single energy 120kV (the same value of CTDI) were used to reconstruct linear and nonlinear fusion images and image quality analysis. Results: for the simulated pulmonary nodules with different CT values, when BC was 0 HUU BW was 0~30HU, higher CNRs could be obtained. There were significant differences in the noise value and SNR of the simulated pulmonary nodules with different CT values in nonlinear fusion, linear fusion and 120kV images. The SNR of different density simulated pulmonary nodules in nonlinear fusion optimization image is significantly higher than that in linear fusion group and 120kV group, while the noise of image is lower in nonlinear fusion optimization group than that in linear fusion group. Conclusion: dual energy CT nonlinear fusion optimization technique can improve the SNR of pulmonary nodules after enhanced CT scan, which can help to diagnose solitary pulmonary nodules more accurately.
【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】：2017
【分類號】：R734.2;R730.44

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