Low-dose CT image denoising method based on generative adversarial network

In order to solve the problems of artifacts and noise in low-dose computed tomography(CT)images in clinical medical diagnosis,an improved image denoising algorithm under the architecture of generative adversarial network(GAN)was proposed.First,a noise model based on style GAN2 was constructed to estimate the real noise distribution,and the noise information similar to the real noise distribution was generated as the experimental noise data set.Then,a network model with encoder-decoder architecture as the core based on GAN idea was constructed,and the network model was trained with the generated noise data set until it reached the optimal value.Finally,the noise and artifacts in low-dose CT images could be removed by inputting low-dose CT images into the denoising network.The experimental results showed that the constructed network model based on GAN architecture improved the utilization rate of noise feature information and the stability of network training,removed image noise and artifacts,and reconstructed image with rich texture and realistic visual effect.

Body Pushers: Low-Dose CT, Always the Best Choice? A Study of the Diagnostic Performance of CT Scout View

Purpose: The purpose of this study has been to evaluate the diagnostic information contained in the CT scout view in the detection of body packing. Materials and methods: Retrospect analysis of 43 CT scans between July 2011 and June 2013 in asymptomatic suspects of body packing (29 men, 14 females, mean age 38 ± 9 years). Results: A total of 11 positive cases of body packing were identified. In 10 (91%) of the cases packets were relatively large and spares in number (3 or less);in 7 (64%) a single packet has been identified. 6 (55%) of the packets were located rectally, 4 (36%) vaginally and in 1 (9%) case multiple small packets of approximately 1 cm in size were found to have been ingested orally. Maximum and minimum diameters were 5.9 ± 3 cm and 2.9 ± 1.4 cm, respectively. The mean weight of packets was 7.5 ± 4.2 g (range 2 - 54 g). In 73% (n = 8) heroin had been detected;other drugs such as cocaine (n = 1) and cannabis (n = 1) were encountered once, respectively. One packet was identified retrospectively and its content could therefore not be identified. The average effective dose was 3.8 ± 2.1 mSv for CT, of that 0.12 ± 0.01 mSv was required for the CT scout view. Conclusion: If CT scout view were treated as a diagnostic image, some CT scans may be omitted, thereby maintaining streamlined operations and achieving further dose reduction jointly in the workup of body packing.

Mortality outcomes of low-dose computed tomography screening for lung cancer in urban China:a decision analysis and implications for practice

Background: Mortality outcomes in trials of low-dose computed tomography(CT) screening for lung cancer are inconsistent. This study aimed to evaluate whether CT screening in urban areas of China could reduce lung cancer mortality and to investigate the factors that associate with the screening effect.Methods: A decision tree model with three scenarios(low-dose CT screening, chest X-ray screening, and no screening) was developed to compare screening results in a simulated Chinese urban cohort(100,000 smokers aged45-80 years). Data of participant characteristics were obtained from national registries and epidemiological surveys for estimating lung cancer prevalence. The selection of other tree variables such as sensitivities and specificities of low-dose CT and chest X-ray screening were based on literature research. Differences in lung cancer mortality(primary outcome), false diagnoses, and deaths due to false diagnosis were calculated. Sensitivity analyses were performed to identify the factors that associate with the screening results and to ascertain worst and optimal screening effects considering possible ranges of the variables.Results: Among the 100,000 subjects, there were 448,541, and 591 lung cancer deaths in the low-dose CT, chest X-ray, and no screening scenarios, respectively(17.2% reduction in low-dose CT screening over chest X-ray screening and 24.2% over no screening). The costs of the two screening scenarios were 9387 and 2497 false diagnoses and 7and 2 deaths due to false diagnosis among the 100,000 persons, respectively. The factors that most influenced death reduction with low-dose CT screening over no screening were lung cancer prevalence in the screened cohort, lowdose CT sensitivity, and proportion of early-stage cancers among low-dose CT detected lung cancers. Considering all possibilities, reduction in deaths(relative numbers) with low-dose CT screening in the worst and optimal cases were16(5.4%) and 288(40.2%) over no screening, respectively.Conclusions: In terms of mortality outcomes, our findings favor conducting low-dose CT screening in urban China.However, approaches to reducing false diagnoses and optimizing important screening conditions such as enrollment criteria for screening are highly needed.

Low-Dose CT Image Denoising Based on Improved WGAN-gp

In order to improve the quality of low-dose computational tomography (CT)images, the paper proposes an improved image denoising approach based on WGAN-gpwith Wasserstein distance. For improving the training and the convergence efficiency, thegiven method introduces the gradient penalty term to WGAN network. The novelperceptual loss is introduced to make the texture information of the low-dose imagessensitive to the diagnostician eye. The experimental results show that compared with thestate-of-art methods, the time complexity is reduced, and the visual quality of low-doseCT images is significantly improved.

Hformer:highly efficient vision transformer for low-dose CT denoising

In this paper,we propose Hformer,a novel supervised learning model for low-dose computer tomography(LDCT)denoising.Hformer combines the strengths of convolutional neural networks for local feature extraction and transformer models for global feature capture.The performance of Hformer was verified and evaluated based on the AAPM-Mayo Clinic LDCT Grand Challenge Dataset.Compared with the former representative state-of-the-art(SOTA)model designs under different architectures,Hformer achieved optimal metrics without requiring a large number of learning parameters,with metrics of33.4405 PSNR,8.6956 RMSE,and 0.9163 SSIM.The experiments demonstrated designed Hformer is a SOTA model for noise suppression,structure preservation,and lesion detection.

Robust restoration of low-dose cerebral perfusion CT images using NCS-Unet

Cerebral perfusion computed tomography(PCT)is an important imaging modality for evaluating cerebrovascular diseases and stroke symptoms.With widespread public concern about the potential cancer risks and health hazards associated with cumulative radiation exposure in PCT imaging,considerable research has been conducted to reduce the radiation dose in X-ray-based brain perfusion imaging.Reducing the dose of X-rays causes severe noise and artifacts in PCT images.To solve this problem,we propose a deep learning method called NCS-Unet.The exceptional characteristics of non-subsampled contourlet transform(NSCT)and the Sobel filter are introduced into NCS-Unet.NSCT decomposes the convolved features into high-and low-frequency components.The decomposed high-frequency component retains image edges,contrast imaging traces,and noise,whereas the low-frequency component retains the main image information.The Sobel filter extracts the contours of the original image and the imaging traces caused by the contrast agent decay.The extracted information is added to NCS-Unet to improve its performance in noise reduction and artifact removal.Qualitative and quantitative analyses demonstrated that the proposed NCS-Unet can improve the quality of low-dose cone-beam CT perfusion reconstruction images and the accuracy of perfusion parameter calculations.

3D/4D CT和3D/4D CBCT在不同运动模式下的模体靶区体积差异

目的评估3D/4D CT和3D/4D CBCT在不同运动模式下模体的内靶区成像的体积差异,以期探讨不同运动模式下各种成像方式在肺体部立体定向放射治疗(SBRT)的图像引导放疗应用的准确性。方法本研究采用CIRS胸部动态模体模拟呼吸运动,使用直径3 cm小球插件,设定振幅分别为5 mm、10 mm的sin(x)和cos 4(x)波形的运动曲线,周期4 s,分别采集3D/4D CT(飞利浦CT)和3D/4D CBCT(医科达加速器)图像,测量不同运动模式下,3D CT、4D CT的平均密度投影CT(4D CT-AIP)、4D CT的最大密度投影CT(4D CT-MIP)、4D CT的全部时相(4D CT-ALL%)和3D CBCT、4D CBCT的平均密度投影CT(4D CBCT-AIP)、4D CBCT的最大密度投影CT(4D CBCT-MIP)各自图像插件小球内靶区体积并进行分析。结果3D CT的靶区体积最小;4D CT-ALL、4D CT-MIP和4D CBCT-MIP三者靶区体积大小接近;3D CT的ITV与ITV-ALL的相似度最低,3D CBCT的ITV与ITV-ALL的相似度接近,4D CT和4D CBCT的ITV(MIP-ALL)的相似度最高,4D CT和4D CBCT图像ITV(AIP-ALL)的相似度均低于ITV(MIP-ALL)。结论对于运动靶区,4D CT联合4D CBCT更能准确提供各时相的肿瘤靶区勾画和运动轨迹验证,是一种可靠的肺SBRT定位及引导模式。

基于CT扫描受压注浆体试块三维孔裂隙结构参数表征

目的为研究注浆体试块单轴压缩过程中孔裂隙结构演化特征,方法以级配砂砾注浆体试块为研究对象,对其单轴压缩过程分阶段进行工业CT扫描,并采用AVIZO对CT切片进行分析,重构孔裂隙结构三维模型,定量表征孔裂隙与孔喉特征参数。结果结果表明:单轴压缩下,试块依次经历孔裂隙萌生、发育、扩展与贯通阶段,孔裂隙演化特征比较明显,萌生阶段孔隙数增幅为14.41%,无明显贯通;发育阶段孔隙数增加326.91%,伴有一定数目孔隙贯通;扩展阶段孔隙数减少了57.79%,孔隙等效直径最大值增幅为223.45%,大部分孔隙贯通为裂隙;贯通阶段孔裂隙数目几乎不变,孔隙等效直径最大值增幅为92.83%,裂隙贯通后形成多个破裂面。峰值后试块出现连通孔隙,该阶段注浆体孔隙与喉道发育完全,试块破坏。结论研究结果可为后续破碎岩石注浆工程实践提供参考。

宽体探测器CT血管造影与超声心动图对小儿先天性心脏病的诊断效能

目的探讨宽体探测器CT血管造影(computer tomography angiography,CTA)与超声心动图(ultrasound cardiogram,UCG)在小儿先天性心脏病(congenital heart disease,CHD)的诊断效能。方法回顾性分析2019-08/2023-09月作者医院收治的65例疑似CHD患儿的影像学资料,所有患儿均行心脏CTA及UCG检查。对两种检查方式的图像质量进行主观评价并比较其差异;以手术或数字减影血管造影(digital subtraction angiography,DSA)为“金标准”,对比两种检查方式在诊断CHD的灵敏度、特异度、阳性预测值、阴性预测值及准确率的差异,并应用Kappa检验比较与“金标准”结果的一致性;采用受试者工作特征(receiver operating characteristic,ROC)曲线分析两种检查方式对小儿CHD的诊断效能。结果CTA诊断小儿CHD心外畸形图像质量主观评分明显高于UCG,二者比较差异具有统计学意义(P<0.05),心内畸形图像质量主观评分二者比较差异无统计学意义(P>0.05)。两名医师对图像质量主观评分的一致性较好(κ=0.802)。CTA、UCG诊断小儿CHD心内畸形准确率比较差异无统计学意义(P>0.05);CTA诊断小儿CHD心外畸形准确率为96.43%,显著高于UCG 50.00%,组间比较差异具有统计学意义(P<0.05)。CTA诊断小儿CHD的灵敏度、特异度、阳性预测值、阴性预测值及准确率分别为90.00%、60.00%、96.43%、33.33%及87.69%,与手术或DSA结果一致性较好(κ=0.766);UCG诊断CHD的灵敏度、特异度、阳性预测值、阴性预测值及准确率分别为83.33%、20.00%、92.59%、9.09%及79.81%,与手术或DSA结果一致性一般(κ=0.522)。CTA、UCG两种检查方式诊断小儿CHD的灵敏度、特异度、阴性预测值及准确率差异比较均有统计学意义(P均<0.05)。ROC曲线分析结果显示,CTA与UCG诊断小儿CHD的曲线下面积(area under the cure,AUC)分别为0.853和0.773,二者比较差异有统计学意义(P<0.05)。结论宽体探测器CTA在小儿CHD心外畸形方面的诊断效能优于UCG,而在心内畸形方面稍差,因此建议二者联合检查,诊断价值更高。

全身磁共振弥散加权成像联合多层螺旋CT对多发性骨髓瘤的诊断价值

目的 探究全身磁共振弥散加权成像(WB-DWI)联合多层螺旋CT对多发性骨髓瘤的诊断价值。方法 选取2019年6月~2023年1月于我院收治的80例多发性骨髓瘤患者为研究对象,并按照检测方式将其分为WB-DWI组(n=25)、多层螺旋CT组(n=25)、联合组(n=30)。分析WB-DWI、多层螺旋CT单一及联合对患者累及部位的检出率,分析两种检查方式单一及联合对多发性骨髓瘤的检出情况,通过ROC曲线分析WB-DWI、多层螺旋CT联合诊断多发性骨髓瘤的临床价值。结果 检测结果主要与Durie-Salmon分期、国际骨髓瘤分期相关(P<0.05)。与WB-DWI、多层螺旋CT单一检测对比,联合检测患者累及部位的检出率较高(P<0.05)。在多发性骨髓瘤诊断中WB-DWI、多层螺旋CT联合检测高于单一检测(P<0.05)。与WB-DWI、多层螺旋CT单项诊断对比,两项联合诊断多发性骨髓瘤的敏感度、特异性、准确性均较高(P<0.05)。结论 相较于WB-DWI、多层螺旋CT单项检测,联合检测可有效提升患者病理检出情况,提高对多发性骨髓瘤的诊断价值。

Sinogram denoising via attention residual dense convolutional neural network for low-dose computed tomography

The widespread use of computed tomography(CT)in clinical practice has made the public focus on the cumulative radiation dose delivered to patients.Low-dose CT(LDCT)reduces the X-ray radiation dose,yet compromises quality and decreases diagnostic performance.Researchers have made great efforts to develop various algorithms for LDCT and introduced deep-learning techniques,which have achieved impressive results.However,most of these methods are directly performed on reconstructed LDCT images,in which some subtle structures and details are readily lost during the reconstruction procedure,and convolutional neural network(CNN)-based methods for raw LDCT projection data are rarely reported.To address this problem,we adopted an attention residual dense CNN,referred to as AttRDN,for LDCT sinogram denoising.First,it was aided by the attention mechanism,in which the advantages of both feature fusion and global residual learning were used to extract noise from the contaminated LDCT sinograms.Then,the denoised sinogram was restored by subtracting the noise obtained from the input noisy sinogram.Finally,the CT image was reconstructed using filtered back-projection.The experimental results qualitatively and quantitatively demonstrate that the proposed AttRDN can achieve a better performance than state-of-the-art methods.Importantly,it can prevent the loss of detailed information and has the potential for clinical application.

多层螺旋CT联合磁共振对新鲜与陈旧骨质疏松椎体压缩性骨折的鉴别诊断

目的:探讨多层螺旋CT联合磁共振对新鲜与陈旧骨质疏松椎体压缩性骨折的鉴别诊断价值。方法:采用回顾性分析的方法,选择2020年1月-2022年12月在我院诊治的80例骨质疏松椎体压缩性骨折患者作为研究对象。通过病史和手术病理等综合诊断确诊为陈旧骨质疏松椎体压缩性骨折的患者35例,确诊为新鲜骨质疏松椎体压缩性骨折的患者45例,将前者作为陈旧骨折组,后者作为新鲜骨折组。所有患者均经过多层螺旋CT、磁共振(MRI)检查,比较新鲜与陈旧骨质疏松椎体压缩性骨折患者MRI和多层螺旋CT表现,比较多层螺旋CT、MRI对80例骨质疏松椎体压缩性骨折患者新鲜与陈旧的诊断准确率,并建立受试者工作特征曲线,比较多层螺旋CT联合MRI对新鲜与陈旧骨质疏松椎体压缩性骨折的诊断效能。结果:通过MRI和多层螺旋CT发现,新鲜骨折组椎体滑脱、椎体骨小梁结构紊乱硬化、椎间盘真空征及变性发生率低于陈旧骨折组,而脊椎旁软组织影、脊髓挫伤出血、骨折线清晰锐利发生率高于陈旧骨折组,差异均有统计学意义(P<0.05)。多层螺旋CT与MRI联合诊断准确率明显高于MRI和多层螺旋CT单一诊断,差异有统计学意义(P<0.05),但多层螺旋CT与MRI单一诊断的准确率比较,差异无统计学意义(P>0.05)。多层螺旋CT联合MRI对新鲜与陈旧骨质疏松椎体压缩性骨折诊断效能明显高于多层螺旋CT或MRI单一诊断,差异有统计学意义(P<0.05)。结论:多层螺旋CT、MRI对于新鲜与陈旧骨质疏松椎体压缩性骨折均具有重要诊断价值,虽然两种诊断方式单一应用的诊断准确率无明显差异,但多层螺旋CT联合MRI可进一步提升新鲜与陈旧骨质疏松椎体压缩性骨折的诊断准确率和诊断效能。

全身动态^(18)F-FDG PET/CT Patlak显像定量参数MR_(FDGmax)和SUV_(max)在大鼠肝炎、肝纤维化及肝硬化阶段的应用价值

目的 通过全身动态^(18)F-FDG PET/CT Patlak显像,探讨定量参数MR_(FDGmax)、SUV_(max)在大鼠肝炎、肝纤维化及肝硬化阶段的应用价值。方法 将24只SD大鼠随机分为4组,每组6只,分别为正常组、肝炎组、肝纤维化组、肝硬化组。根据实验分组,对各组大鼠进行CCl_(4)油溶液复合法诱导;诱导完成分别对各组大鼠进行全身动态^(18)F-FDG PET/CT patlak显像。显像完成后,分析各组肝脏的MR_(FDGmax)、SUV_(max)、CT值;分别提取各组大鼠血清行肝功能指标(AST、 ALT和ALP)检测,并对正常组、肝炎组及肝硬化组的大鼠肝脏行HE染色,肝纤维化组行Masson染色;免疫组化法分析各组肝脏中α-平滑肌肌动蛋白(α-SMA)的表达。数据统计分析采用单因素方差分析、两独立样本t检验和Pearson相关分析。结果 MR_(FDGmax)、SUV_(max)值在正常组、肝炎组、肝纤维化组及肝硬化组之间差异均有统计学意义(F=84.54、38.35,P<0.001)。肝纤维化组与肝硬化组之间CT值差异无统计学意义(t=-0.407,P=0.693),其余各组之间比较差异均有统计学意义(F=112.25,P<0.001)。与正常组相比,实验组AST、ALT及ALP呈阶段性上升,差异均有统计学意义(F=93.32、64.63、145.03,P<0.001);HE染色示正常组肝细胞排列整齐,结构完整;肝炎组大量炎性细胞浸润,脂肪变性;肝硬化组假小叶形成;肝纤维化组Masson染色示胶原纤维增生,被膜增厚。免疫组化检测结果显示,肝炎组、肝纤维化组及肝硬化组α-SMA表达增加,呈阶段性上升,差异有统计学意义(F=80.57,P<0.001)。相关性分析示SUV_(max)与MR_(FDGmax)呈正相关(r=0.967,P<0.01)。肝炎组、肝纤维化组及肝硬化组α-SMA分别与AST、ALT、ALP呈正相关(r=0.924、0.756、0.934,P<0.01)。结论 全身动态^(18)F-FDG PET/CT Patlak显像通过定量参数MR_(FDGmax)、SUV_(max)变化,对监测肝炎、肝纤维化和肝硬化阶段具有一定的应用价值。

Incorporation of circulating tumor cells and whole-body metabolic tumor volume of 18F-FDG PET/CT improves prediction of outcome inⅢB stage small-cell lung cancer

Objective: We investigated the correlation between the number of circulating tumor cells(CTCs) and wholebody metabolic tumor volume(WBMTV) measured by 18 F-fluorodeoxyglucose(FDG) positron emission tomography/computed tomography(PET/CT).The aim was to evaluate the value of the incorporation of CTC number and WBMTV in the prognostic prediction of stage III small-cell lung cancer(SCLC).Methods: One hundred and twenty-nine patients were enrolled in this study.All patients were treated with four cycles of a platinum-based regimen and concurrent chest irradiation,followed by prophylactic cranial irradiation.Blood samples for CTC analysis were obtained from 112 patients before the initiation of chemotherapy(as a baseline),after cycle 1 and after cycle 4.CTCs were measured using the CELLSEARCH? system.The patients underwent pretreatment FDG PET/CT WBMTV,which included all malignant lesions.The Spearman rank test was used to determine the correlation among CTC counts,WBMTV and disease stage.Overall survival(OS) and progression-free survival(PFS) curves were produced using the Kaplan-Meier method,and survival differences between groups were assessed by the log-rank test.Results: The number of CTCs at baseline did not correlate with WBMTV before the initiation of therapy(P=0.241).The number of CTCs at baseline and the WBMTV before the initiation of therapy were independent relevant factors for PFS and OS.The subgroup analysis(Group A: CTC count >19.5 and a WBMTV >266.5cm~3;Group B: CTC count >19.5 and a WBMTV ≤266.5cm~3; Group C: CTC count ≤19.5 and a WBMTV >266.5cm~3;Group D: CTC count ≤19.5 and a WBMTV ≤266.5cm~3) showed that the differences were statistically significant in the median PFS(Group A vs.D,P<0.001; Group B vs.D,P=0.018; Group C vs.D,P=0.029) and in the median OS(Group A vs.D,P<0.001; Group B vs.D,P=0.012).Conclusions: CTC number and WBMTV are related to progression and death in patients with SCLC.The incorporation of CTC number and WBMTV scans can provide a detailed prognostic prediction for SCLC.

全身低剂量CT骨扫描联合MRI在多发性骨髓瘤诊断、分期及分型中的价值分析

目的探讨全身低剂量CT骨扫描联合MRI在多发性骨髓瘤诊断、分期及分型中的价值。方法回顾性选择2020年1月至2023年11月来亳州市人民医院诊治的72例多发性骨髓瘤患者病例资料,根据患者自身的疾病特点及相关部位行全身低剂量CT骨扫描、MRI检查。对比全身低剂量CT骨扫描、MRI及二者联合对多发性骨髓瘤、不同部位骨损害病灶的检出率,分析全身低剂量CT骨扫描、MRI与多发性骨髓瘤临床ISS分期的一致性、全身低剂量CT骨扫描、MRI对临床ISS分期的诊断效能,全身低剂量CT骨扫描、MRI与多发性骨髓瘤临床分型的一致性,全身低剂量CT骨扫描、MRI对多发性骨髓瘤临床分型的诊断效能。结果全身低剂量CT骨扫描联合MRI对多发性骨髓瘤的检出率明显较单一检查检出率高,差异有统计学意义(P<0.05)。二者联合对多发性骨髓瘤脊柱骨损害检出率明显较单一检查检出率高,差异有统计学意义(P<0.05);二者联合对颈椎、盆骨、腰椎、四肢及胸椎骨损害的检出率较单一检查高,但组间比较差异无统计意义(P>0.05)。全身低剂量CT与临床ISS分期的Kappa值为0.773(P=0.000),MRI与临床ISS分期的Kappa值为0.719(P=0.000),二者联合与临床ISS分期的Kappa值为0.971(P=0.000),二者联合与ISS分期一致性良好,全身低剂量CT骨扫描、MRI与ISS分期一致性较好。全身低剂量CT骨扫描联合MRI对临床ISS分期Ⅰ期、Ⅱ期的诊断特异度、对Ⅲ期的诊断敏感度明显较单一检查高,差异均有统计学意义(P<0.05);二者联合对Ⅰ期、Ⅱ期的诊断敏感度、对Ⅲ期的诊断特异度较单一诊断高,但组间比较差异无统计学意义(P>0.05)。全身低剂量CT骨扫描与临床分型的Kappa值为0.841,MRI检查与临床分型的Kappa值为0.801,二者联合与临床分型的Kappa值为0.980,CT、MRI及二者联合与临床分型的一致性良好(均P=0.000)。全身低剂量CT骨扫描联合MRI对多发性骨髓瘤临床分型IgG、IgD型、其他分型的诊断特异度、对IgA型的诊断敏感度明显较单一检查高,差异均有统计学意义(P<0.05);二者联合对IgG型、IgD型、其他分型的诊断敏感度、对IgA型的诊断特异度较单一诊断高,但组间比较差异无统计学意义(P>0.05)。结论全身低剂量CT骨扫描联合MRI对多发性骨髓瘤诊断准确率较单一检查高,对临床分期、分型的诊断一致性较好,二者联合可在一定程度上评估多发性骨髓瘤的诊断、分期及分型。

定量CT评估肌肉减少症和脂肪组织含量与肝癌TACE联合PD-1单抗治疗预后的相关性

目的:探讨定量CT评估的肌肉减少症和脂肪组织含量与接受经导管动脉化疗栓塞术(TACE)联合程序性死亡受体1(PD-1)单抗治疗的肝细胞癌(HCC)患者预后的关系。方法:回顾性收集2019年1月-2022年1月接受TACE联合PD-1单抗治疗的HCC患者77例。所有患者在首次联合治疗前1个月内接受定量CT扫描,并测量L3椎体水平骨骼肌横截面积、总脂肪面积、皮下脂肪面积和内脏脂肪面积,计算骨骼肌指数(SMI)、总脂肪指数(TATI)、皮下脂肪指数(SATI)和内脏脂肪指数(VATI)。通过绘制受试者操作特征(ROC)曲线计算TATI、SATI和VATI最佳截断点。通过SMI评估肌肉减少症。结果:ROC曲线显示TATI、SATI和VATI的截断点分别为61.75 cm^(2)/m^(2)、30.52 cm^(2)/m^(2)和61.52 cm^(2)/m^(2)。男性的SMI平均值为(48.03±7.34)cm^(2)/m^(2),女性的SMI为(40.96±4.76)cm^(2)/m^(2),肌肉减少症发生率为51.9%(40/77)。多因素分析结果显示,肌肉减少症、SATI和肿瘤直径是HCC患者TACE联合PD-1单抗治疗后无进展生存期的独立影响因素(P<0.05)。在总生存期中,无肌肉减少症和高SATI的患者生存时间明显长于患有肌肉减少症和低SATI,差异具有统计学意义(19.5月vs.10.4月;19.5月vs.13.0月,P<0.05)。结论:肌肉减少症、SATI和肿瘤直径是HCC患者TACE联合PD-1单抗治疗独立预后因素,定量CT评估的肌肉减少症和低皮下脂肪含量与TACE联合PD-1单抗治疗的HCC患者较短的生存期相关。

定量CT测量身体组分在肝硬化门静脉高压并发症中的应用价值

目的:基于定量CT(QCT)探讨肝硬化患者身体组分定量指标与门静脉高压并发症的相关性及其应用价值。方法:纳入2021年11月-2023年2月于本院就诊的134例肝硬化患者,受试者均行腹部CT平扫,收集临床资料并用QCT Pro软件测量每例受试者L2/3层面皮下及内脏脂肪面积(SAT、VAT)、腰椎骨密度(BMD)、肝脏脂肪分数(Fat%-QCT)、L3椎体水平全腹肌和椎旁肌面积(SMA、PMA)及肌内脂肪面积并计算肌内脂肪含量(IMAC-S、IMAC-P)。在不同Child-Pugh分级中进行组间资料对比,并根据有无门静脉高压并发症将患者分为两组比较身体组分差异,Mann-Whitney U检验或Kruskal-Wallis H检验、t检验或单因素ANOVA检验、χ^(2)检验用于各组间基本资料与身体组分的差异性分析;采用二元Logistic回归分析与肝硬化门静脉高压并发症相关的QCT指标,采用受试者操作特征(ROC)曲线分析不同模型的识别效能。结果:Fat%-QCT、SAT、椎旁肌内脂肪面积、IMAC-P在不同Child-Pugh分级中差异有统计学意义(P<0.05);多因素Logistic回归分析显示SAT是肝硬化门静脉高压并发症的独立相关因素(P<0.05,OR为0.987);SAT、SAT联合全腹肌指标、SAT联合椎旁肌指标的ROC曲线下面积(AUC)分别为0.727、0.772、0.769(P<0.05),SAT联合全腹肌指标的敏感度及特异度分别为0.734、0.800,优于SAT、SAT联合椎旁肌指标,识别效能最高。结论:SAT减少是肝硬化门静脉高压并发症风险增加的独立危险因素,SAT联合全腹肌指标能较好地识别肝硬化门静脉高压并发症。

Optimization of Contrast Material Dose for Abdominal Multi-Detector Row CT: Predicting Patient Lean Body Weight by Using Preliminary Transverse CT Images

Estimated LBW could be used to determine the contrast material dose and rate during MDCT. The aim of this study is to test the accuracy of a technique for estimation of lean body weight (LBW) from a single multi-detector row computed tomographic (MDCT) abdominal image, using a bioelectrical body composition analyzer scale as the reference standard. CT images of 21 patients with previously measured LBW (mLBW) were processed using computer-assisted, vendor-specific software (Advantage Windows 4.2;GE Healthcare, Inc). For each transverse image, a fat-fraction was automatically measured as the number of fat pixels (-200 to -50 HU) divided by the total number of pixels having an attenuation value ≥-200 HU. Estimated LBW (eLBW) of five single contiguous sections was calculated in each of three abdominal regions (upper abdomen, mid abdomen and pelvis) by multiplying TBW by (1 – fat-fraction). Bland-Altman plot with limits of agreement was used to assess agreement between mLBW and eLBW. The mean mLBW for all patients was 56 kg (range, 39 - 75 kg). Mean differences and limits of agreement between mLBW and eLBW measurements for the upper abdomen, mid abdomen and pelvis reported were -8.9 kg (-25.6 kg, +7.5 kg), -10.6 kg (-27.7 kg, +6.4 kg), and +0.5 kg (-12.8 kg, +13.8 kg) respectively. eLBW deriving directly from a transverse CT image of the pelvis can accurately predict mLBW.

神经内分泌肿瘤68Ga-DOTATATE联合18F-FDG两日法全身PET/CT显像操作规范专家共识

68Ga-DOTATATE联合18F-FDG两日法低剂量全身PET/CT(total-body PET/CT,TB PET/CT)显像,对神经内分泌肿瘤的诊断、预后评价及异质性评估具有互补作用。国内多家应用TB PET/CT的医疗机构共同制定了两日法联合显像操作规范专家共识。

Delivered Dose Verification for Lung Cancer Stereotactic Body Radiotherapy Using Cone-Beam CT

Purpose: Verified the delivered dose distribution of lung cancer Stereotactic Body Radiotherapy (SBRT) using the cone-beam CT images. Methods: Twenty lung cancer patients who underwent SBRT with 100 CBCT images were enrolled in this study. Delivered dose distributions were recalculated on CBCT images with the deformed and non-deformed methods, respectively. The planned and delivered dose distributions were compared using the dose-volume histograms. Results: The delivered target coverage (V100) per patient inside target volume deviated on average were 0.83% ± 0.86% and 1.38% ± 1.40% for Pct vs. Pcbct and Pct vs. Pdcbct, respectively. The Conformity Index (CI) and Gradient Index (GI) showed a good agreement among the plans. For the critical organs, only minor differences were observed between the planned dose and the delivered dose. Conclusions: CBCT images were a useful tool for setup and dose delivery verification for lung cancer patients who underwent SBRT.