螺旋CT扫描及后处理技术应用技巧

了解螺旋CT的新的基础概念,合理应用螺旋CT扫描和后处理的参数匹配以及后处理方式的选择,是目前诊断医师应当掌握的。掌握它们的应用技巧,可以改善病灶的检出、定性和定量,为手术方案的制定提供重要信息。     

3D-CISS序列与3D-TSE序列对Ⅶ～Ⅸ对颅神经成像质量的比较

目的:通过3D-CISS序列与3D-TSE序列对Ⅶ~Ⅸ对颅神经成像质量的比较,确定3D-CISS序列对脑脊液包绕的Ⅶ~Ⅸ对颅神经和淋巴液充盈的内耳迷路成像显示的优势。方法:应用3D-CISS序列与3D-TSE序列分别对第Ⅶ~Ⅸ对颅神经及内耳迷路进行MR成像,在MPR图像及MIP重建图像上最大程度的显示颅神经及内耳迷路,并对两种序列的成像质量进行统计比较。结果:面神经的脑池段、内听道近段及远段、前庭蜗神经的脑池段及内听道近段、耳蜗、前庭及半规管在两个序列中全部以100%的几率显示;蜗神经、前庭上神经、前庭下神经及舌咽神经在3D-CISS序列、3D-TSE序列的显示几率依次分别为:100%、81.2%;100%、51.4%;100%、42.0%;100%、57.1%;面神经、前庭蜗神经的内听道段、内耳迷路、舌咽神经的3D-CISS序列成像质量明显优于3D-TSE序列成像;面神经、前庭蜗神经的脑池段3D-CISS序列成像质量略优于3D-TSE序列。结论:对于被脑脊液包绕的颅神经和淋巴液充盈的内耳迷路的成像,3D-CISS序列是最佳的选择。     

18F-FDG PET/CT显像在恶性胸膜间皮瘤诊断中的价值

Objective Malignant pleural mesothelioma (MPM) is an uncommon neoplasm arising from mesothelial cells of the pleura. The prognosis is poor with median survival of 4- 12 months. The aim of this study was to evaluate the clinic value of 18F-fluorodeoxyglucose (FDG) PET/CT imaging in the diagno-sis and to staging of MPM and to determine if the mean standardized uptake value (SUVmax) of primary tumor correlates with staging and prognosis. Methods Study was conducted retrospectively including 17 pa-tients with clinical suspicion of MPM from 2002 to 2008. Twelve cases of MPM and 5 cases benign pleural pa-thology were proven by histopathology and clinical follow-up. 18F-FDG PET/CT imaging was performed 1 h af-ter injection of 7.4 MBq/kg 18F-FDG. Patients with MPM confirmed by histopatholagy were divided into two groups: with and without metastasis. PET/CT findings were analyzed to determine if SUVmax of primary tumor correlates with staging and prognosis. Receiver operating characteristic (ROC) curve of SUVmax of primary tumor was evaluated to determine if it was a predictor of metastasis and survival time. Results The difference in SUVmax between MPM and benign pleural were statistical significant (5.78±1.81 vs 2.72± 2.51, t = 2. 8, P < 0.05). The diagnostic sensitivity, specificity and accuracy of 18F-FDG PET/CT imaging for MPM were 100% (12/12) , 4/5 and 94% (16/17). All 7 cases of bone and lymph node metastases were detected by 18F-FDG PET/CT imaging. Area under the curve (AUC) was 0.80. Conclusions 18F-FDG PET/CT imaging is useful in the diagnosis and staging of MPM. High SUVmax in the primary tumor correlates well with prognosis and predication of a greater propensity to have nodal and distant metastasis.     

双简高压注射器在多层螺旋CT冠状动脉造影中的应用

随着多层螺旋CT及心电门控技术的问世,尤其是随着16层多层螺旋CT的出现,冠状动脉多层螺旋CT血管造影(multi-slice spiral CT angiography,MSCTA)已成为现实.作为微创性检查,具有广阔的应用前景,本文把双筒高压注射器多层螺旋CT冠状动脉造影和单筒高压注射器多层螺旋CT冠状动脉造影进行对照分析,初步评价双筒高压注射器冠状动脉MSCTA的临床价值.     

多层螺旋CT在评价强直性脊柱炎骶髂关节病变中的价值

目的探讨强直性脊柱炎(AS)之骶髂关节病变的MSCT表现特点,以提高诊断与鉴别诊断水平。方法78例临床确诊为强直性脊柱炎患者的骶髂关节行MSCT扫描,并进行横断位、冠状位或前倾冠状位后处理多平面重组图像。对骶髂关节CT表现特点进行回顾性分析。结果强直性脊柱炎骶髂关节MSCT表现特点为病变主要累及骶髂关节滑膜部的髂骨侧,常见关节软骨钙化、关节间隙改变、关节面毛糙、面下骨硬化或吸收及骶髂韧带钙化等改变。结论MSCT扫描对AS骶髂关节病变的诊断与鉴别诊断具有很大的价值。     

针刺委中穴正电子发射计算机体层摄影/CT脑功能成像的观察

目的 应用正电子发射计算机体层摄影（PET）／CT脑功能成像技术,观察针刺委中穴在脑内引起的代谢变化,探讨针刺疗法的中枢调节机制。方法 电针刺激8名健康志愿者右侧委中穴,同时行PET／CT脑功能成像,采用相同扫描技术对同8名受试者行无任何穴位刺激的PET／CT脑功能成像。使用统计参数图（SPM）的配对t检验模型,对比针刺委中穴组与静息对照组的差异脑功能图。结果 根据布劳德曼区（Broadmann area,BA）,（1）针刺诱发的平均功能激活脑区：左侧BA10、11、22、38、39、40、44、45、46,右侧BA10,双侧BA19、18以及左侧小脑皮层、屏状核、岛叶（t〉3．36,P〈0．01,k〉30voxels）;（2）针刺诱发平均功能抑制脑区：双侧BA24,左侧BA7、8、19、40,右侧BA1、3、6、20、44和左侧黑质。结论 委中穴与大脑存在着一定的联系,针刺委中穴是通过激活和抑制有功能联系的多个特异脑功能区,并通过神经体液机制共同发挥作用。其中前额区、岛叶及小脑的功能激活和扣带回、顶叶及黑质的功能抑制分析是针刺委中穴的中枢调节机制之一。本研究证明,PET／CT脑功能成像技术有助于揭示中医经络理论,为针刺疗法提供中枢调节机制的可视性试验依据。     

1200例肿瘤患者CT检查辐射剂量的调查研究

目的 调查当前肿瘤患者CT检查的辐射剂量,与国家新标准给出的诊断学参考水平进行对比分析.方法 应用标准模体测量5台不同类型CT在典型扫描条件下的加权CT剂量指数（CTDIw）,并回顾统计900例成年肿瘤患者及300例儿童肿瘤患者的CT检查剂量参数,包括平均容积CT剂量指数（CTDIvol）、剂量长度乘积（DLP）、75％分位DLP值,估算有效剂量.结果 成人头部的CTDIw测量值与参考值处于同一水平,腰椎及腹部的CTDIw测量值小于参考值.对于成年患者,脑血管增强扫描的DLP最高,而腹部增强扫描的有效剂量最大.对于儿童患者,不同年龄段的DLP无明显差别.结论 CTDI虽然可以反映CT断层平面的剂量状况,但不能反映患者检查的总剂量水平.对于需要多次重复扫描的检查,因为有可能造成患者个体的高辐射剂量,国家标准应给出以DLP为单位的诊断学参考水平作为对照.应用个体化的扫描方案是降低儿童剂量的有效手段.     

宝石能谱CT在手足肌腱显示中的初步应用

目的初步评价宝石能谱CT在手足肌腱显示中的临床应用价值。资料与方法对30例手足疾病的患者行宝石能谱CT和MRI扫描,应用能谱分析软件,寻求肌腱与周围组织具有最佳对比噪声比(contrast-to-noise rati-o,CNR)的最佳单能量(keV)值,并比较宝石能谱CT最佳keV图像与常规混合能量的图像质量。同时,比较宝石能谱CT最佳keV成像与MRI扫描对手足肌腱病变的显示能力。结果手足肌腱成像的最佳keV值为65.09±2.98,宝石能谱CT最佳keV图像质量明显优于混合能量图像(P=0.005<0.05)。宝石能谱CT对于肌腱整体外形、迂曲、粘连、受压及断裂等显示较好,但对于肌腱内部及周围腱鞘、滑膜改变不如MRI敏感。结论宝石能谱CT最佳keV(65 keV)成像能够明显提高手足肌腱扫描的图像质量,并可用于临床诊断。在实际工作中,应根据患者情况合理选择能谱CT扫描和MRI扫描。     

双能量CT头颈部血管减影成像的效果评价及临床应用

目的：评价双能量CT在头颈部血管减影中自动去骨的效果及其临床应用价值。方法：52例临床怀疑头颈部血管疾病的患者随机分为2组,分别进行双能量CT血管减影成像和常规CT血管减影成像,分别用双能量处理软件和Neuro-DSA软件自动完成去骨,采用容积重建（VR）、最大密度投影（MIP）、多平面重组（MPR）等多种后处理方法,由两位经验丰富的放射科医生采用双盲法评价两种减影方法的去骨效果,并进行比较;同时结合非减影数据,观察血管病变情况。结果：双能量CT血管减影成像和常规CT血管减影成像的容积CT剂量指数（CTDIvol）分别为（20.5635±0.00977）mGy和（25.5746±0.55827）mGy,两者有显著性差异。两种方法对于颈动脉、椎动脉及整体头颈部血管的满意显示率分别为87.8%,68.0%,83.0%和93.5%,91.8%,92.6%,其中对于颈动脉的显示无明显差异,但双能量CT血管减影对部分椎动脉的减影效果较常规CT血管减影差,主要集中在椎动脉近颅底的部分。另外,双能量CT血管减影成像还发现了多处血管病变,临床符合率为100%。结论：相比头颈部常规CT血管减影,双能量CT血管减影辐射剂量更低,能够有效的去除绝大多数骨骼,为头颈部血管疾病的诊断提供了一种新的无创性检查方法。     

18F-FDG PET/CT显像在恶性胸膜间皮瘤诊断中的价值

Objective Malignant pleural mesothelioma (MPM) is an uncommon neoplasm arising from mesothelial cells of the pleura. The prognosis is poor with median survival of 4- 12 months. The aim of this study was to evaluate the clinic value of 18F-fluorodeoxyglucose (FDG) PET/CT imaging in the diagno-sis and to staging of MPM and to determine if the mean standardized uptake value (SUVmax) of primary tumor correlates with staging and prognosis. Methods Study was conducted retrospectively including 17 pa-tients with clinical suspicion of MPM from 2002 to 2008. Twelve cases of MPM and 5 cases benign pleural pa-thology were proven by histopathology and clinical follow-up. 18F-FDG PET/CT imaging was performed 1 h af-ter injection of 7.4 MBq/kg 18F-FDG. Patients with MPM confirmed by histopatholagy were divided into two groups: with and without metastasis. PET/CT findings were analyzed to determine if SUVmax of primary tumor correlates with staging and prognosis. Receiver operating characteristic (ROC) curve of SUVmax of primary tumor was evaluated to determine if it was a predictor of metastasis and survival time. Results The difference in SUVmax between MPM and benign pleural were statistical significant (5.78±1.81 vs 2.72± 2.51, t = 2. 8, P < 0.05). The diagnostic sensitivity, specificity and accuracy of 18F-FDG PET/CT imaging for MPM were 100% (12/12) , 4/5 and 94% (16/17). All 7 cases of bone and lymph node metastases were detected by 18F-FDG PET/CT imaging. Area under the curve (AUC) was 0.80. Conclusions 18F-FDG PET/CT imaging is useful in the diagnosis and staging of MPM. High SUVmax in the primary tumor correlates well with prognosis and predication of a greater propensity to have nodal and distant metastasis.