泌尿系结石CT征象与手术方式的相关性：NLP研究

目的:以自然语言处理(NLP)方法研究泌尿系结石CT报告征象与临床手术方式的相关性.方法:回顾性选取HIS中因泌尿系结石行CT检查、并在本院行外科处理的住院患者资料,包括CT报告、出院小结中记录的诊疗经过,形成记录文档.使用不同NLP模型研究CT报告中结石的影像特征与手术方式的相关性.结果:共纳入371例连续患者的资料用于分析,其中行经皮肾镜碎石取石术(PNL) 142例,输尿镜碎石术(URL) 190例,输尿管软镜碎石术(IRS) 39例.NLP提取“结石”、“炎症”、“输尿管形态”为关键CT特征,十折交叉验证结果显示,经优化后的NLP对结石手术(URL和PNL)分类符合率为0.730,ROC曲线下面积为0.741.结论:NLP用于CT结石特征分析是可行的,可为临床决策提供一定的帮助.     

泌尿系结石患者手术方式的选择：“临床信息+CT特征”的预测效能

目的:探讨泌尿系结石手术前的临床信息(症状、体征等)和CT报告与手术方式的相关性.方法:选取因泌尿系结石住院治疗的患者的病例资料,导出有完整术前资料的患者文档,以自然语言处理(NLP)技术对文档进行分析,提取加工其中的关键信息,研究术前关键信息与手术方式的相关性.结果:收集连续患者资料371例,行输尿镜碎石术(URI)患者190例,行经皮肾镜碎石取石术(PNL)患者142例,行输尿管软镜碎石术(RIRS)患者39例.利用NLP比较临床信息、CT报告与手术方式的相关性,单纯“CT报告”分类符合率为0.456,ROC曲线下面积为0.608;“CT报告+临床信息”分类符合率为0.461,ROC曲线下面积为0.618.增加临床信息后,NLP模型的分类符合率未见明显变化,但决策树路径变长,节点变多,规则复杂,不利于临床使用.结论:对于拟行手术的泌尿系结石患者,手术前的CT报告与手术方式具有相关性,可为手术方式的临床决策提供直接有效的信息.增加症状和体征的临床信息,不能提高预测手术方式的符合率.     

双能CT对离体泌尿系尿酸结石的诊断价值

目的:探讨双能CT对离体泌尿系尿酸结石的诊断价值。方法:搜集经体外光谱分析证实的63枚离体泌尿系结石(其中尿酸结石9枚,非尿酸结石54枚)。模拟体内环境,对结石进行常规CT扫描及双能CT扫描。后处理时采用单能模式(40和140keV)重建,统计结石的能谱曲线类型,测量40和140keV时结石的CT值、有效原子序数及常规扫描时CT值。计算上述参数对不同成分的结石进行鉴别诊断的敏感度和特异度。统计方法采用Kruskal-Wallis U检验及操作者工作特征曲线(ROC)分析。结果:尿酸结石9枚中有7枚(77.8%)呈上升型曲线,其它56枚结石均为下降型曲线,此征象诊断尿酸结石的敏感度为77.8%,特异度100%,阳性预测值100%,阴性预测值96.4%。尿酸结石常规扫描时CT值(403±112)HU,非尿酸结石(854±335)HU,两者之间差异有统计学意义(Z=-3.869,P<0.01);ROC分析曲线下面积(Az)为0.905,以564HU为阈值,诊断尿酸结石的敏感度为100%,特异度76.4%。40keV单能图像上:尿酸结石CT值(341±127)HU,非尿酸结石(1689±853)HU,两者之间差异有统计学意义(Z=-4.5,P<0.01);ROC分析Az为0.971,以615HU为阈值,诊断尿酸结石的敏感度为100%,特异度88.9%。140keV单能图像上:尿酸结石CT值(404±119)HU,非尿酸结石(445±130)HU,两者之间差异无统计学意义(Z=-0.778,P=0.436);ROC分析Az为0.581。有效原子序数:尿酸结石7.02±0.43,非尿酸结石11.93±2.16,两者之间差异具有统计学意义(Z=-4.65,P<0.01);ROC分析Az为0.988,以7.96为阈值,诊断尿酸结石的敏感度100%,特异度92.6%。结论:双能CT测量有效原子序数及40keV单能图像上CT值测量对尿酸结石及非尿酸结石的鉴别诊断价值较高,较常规平扫CT的诊断特异性高。上升型能谱曲线是诊断尿酸结石的可靠征象。     

非增强螺旋CT低剂量扫描在泌尿系结石诊断中的可行性

目的探讨非增强螺旋CT低剂量扫描在诊断急性腰腹痛或怀疑泌尿系结石中的可行性。方法选择30例临床急性腰腹痛或怀疑患有泌尿系结石而未进行过螺旋CT扫描的患者进行常规剂量和低剂量扫描,扫描层厚10 mm,重叠重建1 mm,并进行MPR等后处理。对获得的图像进行诊断敏感性及准确性分析。结果图像经两名经验丰富的放射科医师进行了评估,所有低剂量扫描图像均获得成功。低剂量螺旋CT扫描中30例患者检出35枚结石,敏感性100%,准确性96.5%。结论研究表明,低剂量螺旋CT扫描对于泌尿系结石的诊断是安全并且敏感的,同时较常规剂量扫描明显减少了患者所接受的辐射剂量。     

结肠淤积影像学表现对泌尿系结石诊断的临床意义

目的:探讨泌尿系结石导致结肠淤积的影像学表现与临床意义.材料和方法:回顾性分析临床以及影像学证实的52例泌尿系结石导致的结肠淤积病例,研究结肠淤积的影像学表现和结石与肠淤积问关系.结果:结肠淤积的主要征象:①累及多个肠段的结肠充气(36/52,69.23%),平均最大横径为38.9mm.②左半结肠内少量内容物积聚(29/52,55.77%).③结肠充气肠段以连续性为特征.④肠内壁光滑,平均肠壁厚度为2.8mm.⑤结肠袋和黏膜皱襞保留(28/52,53.85%).⑥结肠壁和结肠系膜无水肿.结石治疗前后肠淤积程度有显著差异(t=2.97,P=0.025).结论:结肠淤积表现有助于诊断隐匿性泌尿系结石.     

泌尿系结石的个体化预防研究现状

泌尿系结石包括肾、输尿管、膀胱和尿道结石,是泌尿外科常见病、多发病.目前发病率高达4％～13％,并呈上升趋势,发病率男、女比例为2 ～3:1[1-2].我国南方为泌尿系结石高发区,是世界上3个主要的泌尿系结石高发区之一.     

双源双能量CT检测泌尿系结石的研究进展

泌尿系结石(以下简称结石)是泌尿系统最常见的疾病之一,患病率1%~5%,治疗后易复发,10年复发率高达50%[1]。X线平片常作为初筛方法,可发现绝大部分的阳性结石,缺点是不能发现阴性结石。超声检查无辐射,适用于结石筛查和随访。常规CT诊断结石的灵敏度和特异性高,检查快速,已成为结石影像学检查中最重要的方法之一。但是,上述方法均不能准确可靠地判断结石成分。分析结石成分对于推测结石病因、研究     

低剂量非增强多排螺旋CT扫描探查尿路结石:模型研究

目的:探讨将低剂量多排螺旋CT(MDCT)扫描技术应用我国成人尿路结石探查的可行性方案及其临床应用的可靠性。方法:参照228例体重75kg以下成人腹盆部骶髂关节水平的体径值制作含有各种组织成分并在其中植入2～5mm的草酸钙结石和7mm管径的水管模型;使用GE Lightspeed 16CT机对模型进行常规剂量和一系列低剂量扫描,筛选出可满足结石诊断要求的低剂量可行性扫描方案,并应用于临床探查尿路结石评价其可靠性。结果:辐射量CT-DIvol为2.67、2.99和3.4mGy的3个序列图像质量基本可满足诊断。选择其中CTDIvol为2.99的序列,扫描参数为120kV、60mA、扫描时间0.5s/r、扫描层厚5mm、螺距0.938应用于临床,检查病例104例,诊断尿路结石的灵敏度、特异度分别为96.67%和88.64%;常规剂量尿路结石检查病例100例,其灵敏度、特异度分别为98.18%和93.33%;比较两种方法的灵敏度与特异度的95%可信区间有重叠,表示两种方法的特异度与灵敏度无统计学差异。结论:应用合适的低剂量MDCT扫描序列探查成人尿路结石是可行、可靠的。     

多模态 MR与CT小肠造影诊断小肠肿瘤性疾病的对比观察

目的：比较多模态 MR 小肠口服造影法与 CT 小肠造影在诊断小肠肿瘤性疾病中的价值。方法：对本院2012年2月至2014年8月对怀疑有小肠肿瘤的65例患者行CT和多模态MR小肠造影检查。由两位腹部影像学医师分别对CT及 MR图像进行分析,记录十二指肠、近段空肠、远段空肠、近段回肠以及远段回肠肠管的病变累及情况,并与手术以及内镜活检病理结果进行对照。结果：经手术及内镜病理证实,65例中共37例患者有38个小肠肿瘤病灶（腺癌6例,淋巴瘤7例,间质瘤18例,神经内分泌肿瘤3例,海绵状血管瘤2例,脂肪瘤2例）。CT及 MRI对小肠肿瘤性病变的检出率分别为97．4％（37／38）和94．7％（36／38）;McNemar检验结果显示,CT小肠显像与多模态小肠 MR口服造影法对于多部位侵犯的小肠肿瘤性病变的诊断敏感度和特异度的差异无统计学意义（P＞0．05）。两例黏膜海绵状血管瘤伴出血仅在CT图像上显示。结论：多模态 MR小肠口服造影法与CT小肠造影均是诊断小肠肿瘤性疾病的有效手段。     

Dual-energy CT virtual non-calcium technique for detection of bone marrow edema in patients with vertebral fractures: A prospective feasibility study on a single- source volume CT scanner

ObjectivesDual-energy computed tomography (DECT) is a recent development for detecting bone marrow edema (BME) in patients with vertebral compression fractures. The aim of this pilot study was to determine the reliability of single-source DECT in detecting vertebral BME using magnetic resonance imaging (MRI) as standard of reference.Materials and methodsNine patients with radiographic thoracic or lumbar vertebral compression fractures underwent both, DECT on a 320-row single-source scanner and 1.5 T MRI. Virtual non-calcium (VNC) images were reconstructed from the DECT volume datasets. Three blinded readers independently scored images for the presence of BME. Only vertebrae with loss of height in radiography (target vertebrae) were included in the analysis. A vertebra was counted as positive if two readers agreed on the presence of BME. Cohen’s kappa was calculated for interrater comparison. Intervertebral ratios of target and the reference vertebra were compared for CT attenuation and MR signal intensity in a reference vertebra using Spearman correlation. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated.ResultsFourteen target vertebrae with a radiographic height loss were identified; eight of them showed BME on MRI, while DECT identified BME in 7 instances. There were no false positive virtual non-calcium images, resulting in a sensitivity of 0.88 (0.75–1.0 among all readers) and specificity of 1.0 (0.81–1.0). Interrater agreement was inferior for DECT (κ = 0.63–0.89) compared to MRI (κ = 0.9–1.0). Intervertebral ratio in VNC images strongly correlated with short-tau inversion recovery (r = 0.87) and inversely with T1 (-0.89). SNR (0.2 +/− 0.2 in VNC and 16.7 +/− 7.3 in STIR) and CNR (0.2 +/− 0.3 and 7.1 +/− 6.3) values were inferior in VNC.ConclusionsDetecting BME with single-source DECT is feasible and allows detection of vertebral compression fractures with reasonably high sensitivity and specificity. However, image quality of VNC reconstructions has to be improved to achieve better interrater agreement. Nonetheless, DECT might accelerate the diagnostic work-flow in patients with vertebral compression fractures in the future and reduce the number of additional MRI examinations.     

Intermodality comparison between 3D perfusion CT and 18F-FDG PET/CT imaging for predicting early tumor response in patients with liver metastasis after chemotherapy: Preliminary results of a prospective study

Objectives

To evaluate the feasibility of 3D perfusion CT for predicting early treatment response in patients with liver metastasis from colorectal cancer.

Methods

Seventeen patients with colon cancer and liver metastasis were prospectively enroled to undergo perfusion CT and 18F-FDG-PET/CT before and after one-cycle of chemotherapy. Two radiologists and three nuclear medicine physicians measured various perfusion CT and PET/CT parameters, respectively from the largest hepatic metastasis. Baseline values and reduction rates of the parameters were compared between responders and nonresponders. Spearman correlation test was used to correlate perfusion CT and PET/CT parameters, using RECIST criteria as reference standard.

Results

Nine patients responded to treatment, eight patients were nonresponders. Baseline SUV_mean30 on PET/CT, reduction rates of 30% metabolic volume and 30% lesion glycolysis (LG₃₀) on PET/CT and blood flow (BF) and flow extraction product (FEP) on perfusion CT after chemotherapy were significantly different between responders and nonresponders (P = 0.008–0.046). Reduction rates of BF (correlation coefficient = 0.630) and FEP (correlation coefficient = 0.578) significantly correlated with that of LG₃₀ on PET/CT (P < 0.05).

Conclusion

CT perfusion parameters including BF and FEP may be used as early predictors of tumor response in patients with liver metastasis from colorectal cancer.