The air kerma, which is the amount of energy given off by a radioactive substance, is essential for medical specialists who use radiation to diagnose cancer problems. The amount of energy that a photon has when it hits something can be described as the air kerma (the amount of energy that was deposited in the air when the photon passed through it). Radiation beam intensity is represented by this value. Hospital X-ray equipment has to account for the heel effect, which means that the borders of the picture obtain a lesser radiation dosage than the center, and that air kerma is not symmetrical. The voltage of the X-ray machine can also affect the uniformity of the radiation. This work presents a model-based approach to predict air kerma at various locations inside the radiation field of medical imaging instruments, making use of just a small number of measurements. Group Method of Data Handling (GMDH) neural networks are suggested for this purpose. Firstly, a medical X-ray tube was modeled using Monte Carlo N Particle (MCNP) code simulation algorithm. X-ray tubes and detectors make up medical X-ray CT imaging systems. An X-ray tube’s electron filament, thin wire, and metal target produce a picture of the electrons’ target. A small rectangular electron source modeled electron filaments. An electron source target was a thin, 19,290 kg/m3 tungsten cube in a tubular hoover chamber. The electron source–object axis of the simulation object is 20° from the vertical. For most medical X-ray imaging applications, the kerma of the air was calculated at a variety of discrete locations within the conical X-ray beam, providing an accurate data set for network training. Various locations were taken into account in the aforementioned voltages inside the radiation field as the input of the GMDH network. For diagnostic radiology applications, the trained GMDH model could determine the air kerma at any location in the X-ray field of view and for a wide range of X-ray tube voltages with a Mean Relative Error (MRE) of less than 0.25%. This study yielded the following results: (1) The heel effect is included when calculating air kerma. (2) Computing the air kerma using an artificial neural network trained with minimal data. (3) An artificial neural network quickly and reliably calculated air kerma. (4) Figuring out the air kerma for the operating voltage of medical tubes. The high accuracy of the trained neural network in determining air kerma guarantees the usability of the presented method in operational conditions.

目的 探讨CT扫描定量分析鉴别诊断惰性肺腺癌与浸润性肺腺癌的价值.方法 回顾性分析2017年8月-2021年5月浙江省台州市第一人民医院经手术病理证实的98例长径小于30mm的T1期肺腺癌患者,对其胸部CT平扫薄层图像进行主观形态学分析,并利用LIFEx软件通过人工分割,定量提取强度特征、形态特征及纹理特征等CT定量分析特征后进行比较分析.结果 病灶的体积、直方图的均匀性、峰度差异具有统计学意义(P＜0.05),偏度差异无统计学意义(P＞0.05),而CT衰减值中的均值、标准差、最大值差异均有统计学意义(P＜0.05).结论 CT扫描的定量分析特征有助于区分惰性和浸润性肺腺癌,为肺结节患者提供选择干预措施的机会.

目的 探讨多模式电子计算机断层扫描(Computed tomography,CT)下行溶栓时强化降压治疗对缺血性脑卒中(cerebral Ischemic stroke,CIS)患者的疗效及预后价值.方法 选取2017年2月至2019年3月于我院进行多模式CT下溶栓治疗的CIS患者201例,随机数字表法分为对照组(100例)、观察组(101例),对照组患者行标准化降压干预,观察组患者行强化降压手段干预.比较两组患者血压、血液流变学水平,评价两组患者神经功能、日常生活能力.比较两组治疗有效率及预后情况.结果 溶栓后观察组患者收缩压、舒张压、高切黏度、低切黏度、血浆比黏度、红细胞比容均低于对照组(P＜0.05);观察组患者NDS评分低于对照组,barthel评分高于对照组,治疗总有效率高于对照组,预后情况优于对照组(P＜0.05).结论 在多模式CT下行溶栓时对患者进行强化降压干预,能够改善患者血液流变学情况,有着较好的预后效果.

目的 探讨肝细胞肝癌患者MRI特征在鉴别异常凝血酶原(PIVKA-Ⅱ)阳性和阴性中的价值.方法 回顾2018年1月至2020年3月台州市第一人民医院确诊的91例肝细胞肝癌患者的临床资料,根据PIVKA-Ⅱ水平分为PIVKA-Ⅱ阳性组45例(PIVKA-Ⅱ>32.01 mAU/ml)和PIVKA-Ⅱ阴性组46例(PIVKA-Ⅱ≤32.01 mAU/ml).比较两组患者MRI特征和临床资料.应用单因素以及多因素logistic回归分析PIVKA-Ⅱ阳性肝癌患者MRI特征的影响因素.结果 91例患者MRI增强均呈"快进快出"的强化模式.与PIVKA-Ⅱ阴性组比较,PIVKA-Ⅱ阳性组表现扩散系数(ADC)值更低,肿瘤更大,易表现为局部突出、弥散加权成像(DWI)靶征样改变,动脉期强化率更低(均P<0.05).多因素logistic回归分析发现,ADC值(OR=0.989,95％CI:0.983～0.995,P<0.05),肿块大小(OR=1.130,95％CI:1.055～1.211,P<0.05),DWI靶征样改变(OR=5.904,95％CI:1.336～26.096,P<0.05)是PIVKA-Ⅱ阳性肝细胞肝癌MRI特征的影响因素.结论 PIVKA-Ⅱ阳性与PIVKA-Ⅱ阴性肝细胞肝癌患者在MRI增强模式上表现一致,但其ADC值、肿块大小、DWI靶征样改变有助于鉴别PIVKA-Ⅱ阳性或阴性.

目的 分析磁共振成像(MRI)不同扫描序列对胎盘植入患者诊断及分级评估的价值.方法 选择2017 年3 月-2019年6月台州市第一人民医院妇产科收治的52例产前B超检查怀疑胎盘植入的孕妇为研究对象,采用1.5T MRI 系统对患者分别进行T2加权成像(T2WI)序列、单次激发平面回波成像(SSEPI)序列、单次激发快速自旋回波(SSFSE)序列扫描.以病理检查结果为金标准,观察不同类型胎盘植入3 种序列影像学图像,分析3 种序列MRI特征检出情况及对不同胎盘植入类型及分级的评估价值.结果 3种序列对胎盘信号不均、子宫肌层连续性中断、胎盘侵及子宫肌层、胎盘与子宫肌层间低信号带消失的检出率比较差异有统计学意义(均P＜0.05).T2WI、SSEP列、SSFSE诊断胎盘植入的灵敏度分别为25.00％(4/20)、80.00％(16/20)、90.00％(18/20),特异度分别为87.50％(28/32)、87.50％(28/32)、93.75％(30/32),阳性预测值分别为55.56％(4/9)、80.00％(16/20)、90.00％(18/20),阴性预测值分别为65.11％(28/43)、87.50％(28/32)、93.75％(30/32),诊断符合率分别为61.54％(32/52)、84.62％(44/52)、92.31％(48/52).T2WI与病理检查胎盘植入分级的符合率为65.00％(13/20),SSEPI 与病理检查胎盘植入分级的符合率为80.00％(16/20);SSFSE与病理检查胎盘植入分级的符合率为80.00％(16/20).结论 T2WI易造成伪影,SSEPI可对胎盘植入程度进行定量分析,SSFSE分辨率相对较高,三者联合应用可提高胎盘植入诊断率.

Objective:To detect the expression and methylation of TIA1 in breast cancer and to study its correlation with multi-slice spiral CT signs.Methods:50 patients with breast cancer were collected from Feb.2019 to Mar. 2020. The expression levels of TIA1 in breast cancer tissues and in peritumoral tissues were estimated by quantitative real-time polymerase chain reaction. Bioinformatics software MethPrimer was used for predicting TIA1 promotor and confirmed the existence of cPG island. Methylation-specific PCR (MSP) was performed to detect TIA1 DNA promoter methylation. All patients were examined by multi-slice CT. CT images were analyzed through observing the tumor size, shape, calcification area, lymph node metastasis and margin. The correlation between CT signs and TIA1 methylation status was further analyzed.Results:The expression levels of TIA1 in breast cancer tissues were lower than in peritumoral tissues (0.50±0.12, 0.95±0.10, P=0.00) , while TIA1 DNA promoter methylation rate was higher than in peritumoral tissues (64%, 42%, χ2=4.86, P<0.05) .There were no significant differences in TIA1 DNA promoter methylation rate among patients with different tumor shape and micro calcifications. TIA1 DNA promoter methylation rate in patients with mass diameter≥2 cm were significantly higher than those in patients with mass diameter<2 cm (78.57%, 45.45%, P<0.05) , and TIA1 DNA promoter methylation rate in patients with lymph node metastasis was higher than those without lymph node metastasis (79.17%, 50%, P<0.05) . TIA1 DNA promoter methylation rate in patients with burr at edge of mass was higher than those without burr at edge of mass (80.77%, 45.83%, P<0.05) . Conclusion:There is a correlation between CT imaging signs and TIA1 DNA promoter methylation rate in patients with breast cancer, which can provide more reference for the judgment of malignant degree and prognosis of patients with breast cancer.

目的 评价三维CTA(3D-CTA)检查高危颅内动脉瘤破裂出血的应用价值及筛选敏感性指标.方法 选择手术确诊颅内动脉瘤患者共60例(80个动脉瘤,破裂出血30个),均采用3D-CTA检查,评估动脉瘤数目、位置、形态、长度、高度、瘤颈宽度、瘤体颈比(AR)、入射夹角、载瘤动脉直径、高度/载瘤动脉直径(SR)、瘤体钙化及血栓,分别采用单因素和多因素Logistic回归分析筛选破裂的高危因素,以受试者工作曲线(ROC)评价动脉瘤破裂的诊断价值.结果 单因素分析得出,破裂组患者性别和年龄、动脉瘤数目、位置、高度、载瘤动脉直径、瘤体钙化及血栓与未破裂组比较均无差异(P＞0.05);但破裂组动脉瘤形态、长度、瘤颈宽度、AR、入射夹角和SR与未破裂组比较,差异有统计学意义(P＜0.05).多因素Logistic回归分析得出:子囊、AR＞0.98、入射夹角＞105.4°和SR＞0.42是动脉瘤破裂的独立危险因素(P＜0.05).ROC分析得出:AR诊断动脉瘤破裂的准确性(曲线下面积AUC值)为0.866,临界值1.15;入射夹角诊断准确性为0.845,临界值110°;SR诊断准确性为0.855,临界值0.51.结论 3D-CTA检查高危颅内动脉瘤破裂出血有较好的应用价值,子囊、AR、入射夹角和SR值可能是预测破裂的敏感性指标.

目的 观察冠状动脉CTA与冠状动脉造影在诊断心肌桥-壁冠状动脉(MB-MCA)的应用效果.方法 选取我院就诊的167例疑似心肌缺血患者,分别进行冠状动脉CTA和冠状动脉造影(CAG)检查.比较两种检查方法对MBMCA的诊断效果,测量和分析MB-MCA的长度和狭窄程度.结果 冠状动脉CTA共检出MB-MCA患者37例,而CAG检查共检出MB患者20例,冠状动脉CTA对于MB-MCA的检出率显著高于CAG检查,差异有统计学意义(P＜0.05);以CAG检查结果为参照,可计算出冠状动脉CTA诊断MB的敏感性为90％、特异性为87.1％、阳性预测值为48.6％和阴性预测值为98.5％;冠状动脉CTA对MB-MCA测量的长度和狭窄程度结果均大于CAG测量结果,差异有统计学意义(P＜0.05).结论 冠状动脉CTA在MB-MCA的诊断和测量中具有较高的准确性,具有较好的临床应用及推广价值.

目的:分析Tourette综合征患儿症状严重程度与静息态功能磁共振脑低频振幅(ALFF)的关系.方法:选取台州市第一人民医院2017年2月至2018年4月所收治20例首发Tourette综合征患儿,均接受静息态功能磁共振扫描检查,分别在不同频段对脑ALFF值进行计算,探讨症状严重程度与脑ALFF值的相关性.结果:左额上回眶部、右额中回、左额中回眶部的症状严重程度评分与脑ALFF值表现为正相关(P<0.05);左距状沟、右距状沟及其周围皮质的症状严重程度评分与脑ALFF值表现为负相关(P<0.05).结论:Tourette综合征患儿的症状严重程度与特定区域脑功能活动异常存在显著相关性.

目的 探讨肝脏局灶性结节增生(Focal nodular hyperplasia,FNH)采用腹部超声、CT、MRI诊断的影像学特点,为临床诊断FNH提供依据.方法 回顾性分析2015年6月至2018年6月经医院手术病理检查或肝穿刺活检确诊为FNH的70例患者的临床资料,所有患者均行腹部超声、CT、MRI检查,分别对其影像学特征进行分析,并对诊断符合率进行评价.结果 腹部超声FNH诊断符合率为62.86％,CT FNH诊断符合率为65.71％,MRI FNH诊断符合率为97.14％,MRI诊断符合率显著高于超声和CT,误诊率、漏诊率均低于CT,差异有统计学意义(P＜0.05);超声的漏诊率、诊断符合率与CT相比差异无统计学意义(P＞0.05),CT误诊率低于超声,差异有统计学意义(P＜0.05).结论 腹部超声、CT、MRI检查均可作为FNH的初筛手段,MRI增强扫描三期信号与CT扫描特点具有相似性,但MRI更适合微小病灶的诊断,因此MRI对FNH的诊断更具有临床价值.

目的 探讨磁共振成像(MRI)对老年骨质疏松及骨转移瘤所致脊柱椎体压缩性骨折的鉴别诊断价值.方法 分析80例脊柱椎体压缩性骨折患者的临床资料,对照组46例骨质疏松性脊柱椎体压缩性骨折患者,77节椎节,试验组34例骨转移瘤性脊柱椎体压缩性骨折患者,42节椎节.对比两组MRI影像学特征、磁共振表观扩散系数(ADC值)、血清肿瘤坏死因子(TNF)-α、白细胞介素(IL)-23和IL-6水平.结果 试验组主要以扁平形(23.81％)和倒楔形(71.43％)为主,椎体信号以T1WI低信号(95.24％)、T2WI高信号(90.48％)和DWI高信号(92.86％)为常见信号,椎体后缘形态以膨隆(85.71％)为主,椎弓根以膨大(80.95％)和T1WI低信号(95.24％)为主,椎管软组织以结节肿块(85.71％)和环形增厚(71.43％)为主;对照组主要以楔形(48.05％)和凹陷形(42.86％)为主,椎体信号以DWI低信号(83.12％)、T1WI低信号(67.53％)为常见信号,椎体后缘形态以成角(79.22％)为主.两组椎体形态、椎体后缘形态、椎弓根形态、椎体信号和椎管软组织形态变化水平,差异均有统计学意义(P<0.05).试验组ADC值明显低于对照组,血清TNF-α、IL-23及IL-6水平明显高于对照组(P<0.05).结论 采用MRI扫描及血清炎症因子对骨质疏松及骨转移瘤所致脊柱椎体压缩性骨折的鉴别诊断具有临床指导意义.

Objective To analyze the clinical value of X ray examination, CT examination and MRI examination in the diagnosis of giant cell tumor of bone.Methods 50 patients with giant cell tumor of bone confirmed by postoperative pathology were selected.The patients' X ray, CT scan and MRI imaging examination data were retrospectively analyzed, and the imaging features of giant cell tumor of bone were discussed and summarized.Results The rate of CT examination and MRI examination in the diagnosis of bone destruction was higher than X ray examination, but the difference was not statistically significant (x2=4.181,P>0.05).CT examination and MRI examination in the soap bubble sign, bone crest, liquid plane and soft tissue mass in the diagnostic rate compared with X ray examination was significantly higher, the difference was statistically significant (x2=5.333,22.941,30.000,38.400,64.000,14.166,6.102,all P<0.05).Conclusion The diagnostic accuracy of CT and MRI in giant cell tumor of bone is higher than X ray, but the value of MRI examination in the diagnosis of edema near the tumor is better.

目的：探讨MRT rueFisp序列在评估肝癌侵犯门脉中的应用价值。方法对怀疑为肝癌伴门脉受侵患者MRI平扫、增强扫描及True FISP序列检查。结果 True FISP序列、增强门脉期冠状位诊断结果进行对照分析发现二者的一致性高（Kappa值＝0．811）。增强门脉期冠状位与病理诊断结果进行对照分析，增强门脉期冠状位在对肝癌侵犯门脉的显示有很高的一致（Kappa值＝0．764）。True FISP序列与病理诊断结果进行对照分析，True FISP序列在对肝癌侵犯门脉的显示有很高的一致（Kappa值＝0．757）。结论 MR True FISP序列显示门脉的最佳成像参数和扫描方法，具有高效、省时、实用性强的优点。