COVID-19-related cardiomyopathy:Can dual-energy computed tomography be a diagnostic tool?

BACKGROUND No study on dual energy computed tomography(DECT)has been found in the literature to evaluate possibly fatal cardiac/myocardial problems in corona virus disease 2019(COVID-19)patients.Myocardial perfusion deficits can be found in COVID-19 patients even without any significant coronary artery occlusion,and these deficits can be shown via DECT with a perfect interrater agreement.AIM To assess lung perfusion alterations in COVID-19 patients.To our knowledge,no study using DECT has been performed to evaluate possibly fatal cardiac/myocardial problems in COVID-19 patients.The purpose of this study is to evaluate the role of DECT in the detection of COVID-19-related cardiac diseases.METHODS Two blinded independent examiners evaluated CT images using the 17-segment model according to the American Heart Association’s classification of the segmentation of the left ventricular myocardium.Additionally,intraluminal diseases and abnormalities in the main coronary arteries and branches were investigated.Following segment-by-segment analysis,perfusion deficiencies identified on the iodine map pictures on DECT were identified.RESULTS The study enrolled a total of 87 patients.Forty-two of these individuals were classified as COVID-19 positive,and 45 were classified as controls.Perfusion deficits were identified in 66.6%(n=30)of the cases.All control patients had a normal iodine distribution map.Perfusion deficits were found on DECT iodine map images with subepicardial(n=12,40%),intramyocardial(n=8,26.6%),or transmural(n=10,33.3%)anatomical locations within the left ventricular wall.There was no subendocardial involvement in any of the patients.CONCLUSION Myocardial perfusion deficits can be found in COVID-19 patients even without any significant coronary artery occlusion.These deficits can be shown via DECT with a perfect interrater agreement.Additionally,the presence of perfusion deficit is positively correlated with D-dimer levels.

Dual energy computed tomography for detection of metastatic lymph nodes in patients with hepatocellular carcinoma

BACKGROUND Regional lymph node metastasis in patients with hepatocellular carcinoma(HCC)is not uncommon, and is often under-or misdiagnosed. Regional lymph node metastasis is associated with a negative prognosis in patients with HCC, and surgical resection of lymph node metastasis is considered feasible and efficacious in improving the survival and prognosis. It is critical to characterize lymph node preoperatively. There is currently no consensus regarding the optimal method for the assessment of regional lymph nodes in patients with HCC.AIM To evaluate the diagnostic value of single source dual energy computed tomography(CT) in regional lymph node assessment for HCC patients.METHODS Forty-three patients with pathologically confirmed HCC who underwent partial hepatectomy with lymphadenectomy were retrospectively enrolled. All patients underwent dual-energy CT preoperatively. Regional lymph nodes(n = 156) were divided into either a metastatic(group P, n = 52) or a non-metastasis group(group N, n = 104), and further, according to pathology, divided into an active hepatitis(group P1, n = 34; group N1, n = 73) and a non-active hepatitis group(group P2, n = 18; group N2, n = 31). The maximal short axis diameter(MSAD),iodine concentration(IC), normalized IC(NIC), and the slope of the spectralcurve(λ_(HU)) of each group in the arterial phase(AP), portal phase(PP), and delayed phase(DP) were analyzed.RESULTS Analysis of the MSAD, IC, NIC, and λ_(HU) showed statistical differences between groups P and N(P < 0.05) during all three phases. To distinguish benign from metastatic lymph nodes, the diagnostic efficacy of IC, NIC, and λ_(HU) in the PP was the best among the three phases(AP, PP, and DP), with a sensitivity up to 81.9%,83.9%, and 81.8%, and a specificity up to 82.4%, 84.1% and 84.1%, respectively.The diagnostic value of combined analyses of MSAD with IC, NIC, or λ_(HU) in the PP was superior to the dual energy CT parameters alone, with a sensitivity up to84.5%, 86.9%, and 86.2%, and a specificity up to 83.0%, 93.6% and 89.8%,respectively. Between groups P1 and P2 and groups N1 and N2, only IC, NIC,and λ_(HU) between groups N1 and N2 in the PP had a statistically significant difference(P < 0.05).CONCLUSION Dual-energy CT contributes beneficially to regional lymph node assessment in HCC patients. Combination of MSAD with IC, NIC, or λ_(HU) values in the PP is superior to using any single parameter alone. Active hepatitis does not deteriorate the capabilities for characterization of metastatic lymph nodes.

Amiodarone-induced hepatotoxicity-quantitative measurement of iodine density in the liver using dual-energy computed tomography:Three case reports

BACKGROUND Amiodarone is the drug most commonly used to manage arrhythmias.Long-term amiodarone administration causes hepatotoxicity due to iodine accumulation in the liver.Here,we present three cases of amiodarone-induced hepatotoxicity in patients on long-term oral amiodarone therapy who underwent dual-energy computed tomography(DECT).CASE SUMMARY We report the clinical and iodine density in the liver using DECT in three patients with amiodarone-induced hepatotoxicity.Liver enzymes were increased in these three patients,and abdominal DECT without contrast medium showed highly increased attenuation in the liver.Furthermore,the iodine concentration in the liver was increased.The first patient with amiodarone-induced reversible hepatotoxicity,showed a reversible course of liver function and a decrease in CT values after discontinuation of amiodarone.The second patient on long-term oral amiodarone had increased iodine concentration in the liver and liver damage,the patient eventually developed rapidly progressive pneumonia and died of multiple organ failure.The third patient,showed an increased iodine concentration in the liver and elevated liver enzymes.However,the patient refused radiofrequency ablation for atrial fibrillation and continued oral amiodarone to control atrial fibrillation,and routine liver function tests were required every 3-6 mo in this patient.CONCLUSION DECT is a potentially noninvasive diagnostic tool for quantifying iodine concentration in the liver and monitoring adverse reactions due to amiodarone.

Characterization of ureteral stents by dual-energy computed tomography: Clinical implications

Dual-energy computed-tomography(DECT) has been suggested as the method of choice for imaging urinary calculi due to the modality's high sensitivity for detect-ing stones and its capability of accurately differentiat-ing between uric-acid(UA) and non-UA(predominantly calcium) stones. The clinical significance of the latter feature relates to the differences in management of UA vs non-UA calculi. Like calculi, ureteral stents are assigned color by the dual-energy post-processing algorithm, which may lead to improved or worsened stone visualization based on the resulting stent/stone contrast. Herein we depict the case of a nephrolithiasis patient with bilateral stents, each with different color, clearly displaying the effect of stent color on stone vi-sualization. Further, three-dimensional reconstruction of the DECT images illustrates advantages of this enhancement compared to conventional two-dimensional computed tomography. The resulting stent/stone contrast produces an unanticipated potential advantage of DECT in patients with urolithiasis and stents and may promote improved management decision-making.

Head dual energy-computed tomography angiography versus neuro-digital subtraction angiography

Dual-energy X-ray absorptiometry provides two modes of head computed tomography （CT） angiography scanning： neuro-digital subtraction angiography and dual-energy CT angiography （DE-CTA）. Previous studies have compared image quality, radiation exposure, and bone removal between neuro-digital subtraction angiography and DE-CTA. However, the number of cases was relatively small. The present study examined 300 suspected cases of cerebrovascular disease and observed the methods and duration of post-processing, examination time, and data volume. Results demonstrated similar image quality between the two methods, but lower radiation doses and shorter examination time in DE-CTA. DE-CTA allowed for faster and more stable scanning performance and post-processing methods, facilitating accurate and direct diagnosis of cerebrovascular disease.

Fused monochromatic imaging acquired by single source dual energy CT in hepatocellular carcinoma during arterial phase: an initial experience

Objective： To explore whether single and fused monochromatic images can improve liver tumor detection and delineation by single source dual energy CT （ssDECT） in patients with hepatocellular carcinoma （HCC） during arterial phase. Methods： Fifty-seven patients with HCC who underwent ssDECT scanning at Beijing Cancer Hospital were enrolled retrospectively. Twenty-one sets of monochromatic images from 40 to 140 keV were reconstructed at 5 keV intervals in arterial phase. The optimal contrast-noise ratio （CNR） monochromatic images of the liver tumor and the lowest-noise monochromatic images were selected for image fusion. We evaluated the image quality of the optimal-CNR monochromatic images, the lowest-noise monochromatic images and the fused monochromatic images, respectively. The evaluation indicators included the spatial resolution of the anatomical structure, the noise level, the contrast and CNR of the tumor. Results： In arterial phase, the anatomical structure of the liver can be displayed most clearly in the 65-keV monochromatic images, with the lowest image noise. The optimal-CNR monochromatic images of HCC tumor were 50-keV monochromatic images in which the internal structural features of the liver tumors were displayed most clearly and meticulously. For tumor detection, the fused monochromatic images and the 50-keV monochromatic images had similar performances, and were more sensitive than 65-keV monochromatic images. Conclusions： We achieved good arterial phase images by fusing the optimal-CNR monochromatic images of the HCC tumor and the lowest-noise monochromatic images. The fused images displayed liver tumors and anatomical structures more clearly, which is potentially helpful for identifying more and smaller HCC tumors.

Correlation analysis of dual-energy CT iodine maps with quantitative pulmonary perfusion MRI

AIM:To correlate dual-energy computed tomography(DECT) pulmonary angiography derived iodine maps with parameter maps of quantitative pulmonary perfusion magnetic resonance imaging(MRI).METHODS:Eighteen patients with pulmonary perfusion defects detected on DECT derived iodine maps were included in this prospective study and additionally underwent time-resolved contrast-enhanced pulmonary MRI [dynamic contrast enhanced(DCE)-MRI].DCE-MRI data were quantitatively analyzed using a pixel-by-pixel deconvolution analysis calculating regional pulmonary blood flow(PBF),pulmonary blood volume(PBV) and mean transit time(MTT) in visually normal lung parenchyma and perfusion defects.Perfusion parameterswere correlated to mean attenuation values of normal lung and perfusion defects on DECT iodine maps.Two readers rated the concordance of perfusion defects in a visual analysis using a 5-point Likert-scale(1 = no correlation,5 = excellent correlation).RESULTS:In visually normal pulmonary tissue mean DECT and MRI values were:22.6 ± 8.3 Hounsfield units(HU);PBF:58.8 ± 36.0 mL/100 mL per minute;PBV:16.6 ± 8.5 mL;MTT:17.1 ± 10.3 s.In areas with restricted perfusion mean DECT and MRI values were:4.0 ± 3.9 HU;PBF:10.3 ± 5.5 mL/100 mL per minute,PBV:5 ± 4 mL,MTT:21.6 ± 14.0 s.The differences between visually normal parenchyma and areas of restricted perfusion were statistically significant for PBF,PBV and DECT(P < 0.0001).No linear correlation was found between MRI perfusion parameters and attenuation values of DECT iodine maps(PBF:r = 0.35,P = 0.15;PBV:r = 0.34,P = 0.16;MTT:r = 0.41,P = 0.08).Visual analysis revealed a moderate correlation between perfusion defects on DECT iodine maps and the parameter maps of DCE-MRI(mean score 3.6,k 0.45).CONCLUSION:There is a moderate visual but not statistically significant correlation between DECT iodine maps and perfusion parameter maps of DCE-MRI.

Determinants of Detection of Stones and Calcifications in the Hepatobiliary System on Virtual Nonenhanced Dual-energy CT

Objective To retrospectively determine the features of stones and calcifications in hepatobiliary system on virtual nonenhanced(VNE) dual-energy computed tomography(CT), and to evaluate the possibility of VNE images in diagnosis for those lesions. Methods A total of 128 gall stones and calcifications of the liver found in 110 patients were examined with triple phase abdominal CT scan from July 2007 to December 2011, in which true nonenhanced(TNE) phase and arterial phase were performed with single-energy CT(120 kVp) and portal venous phase was performed with dual-energy CT(100 kVp and 140 kVp). VNE images were generated from the portal venous phase dual-energy CT data sets by using commercially VNC software. The mean CT values for the stone, liver, bile and paraspinal muscle, mean lesion density and size in area dimension, contrast-to-noise ratio(CNR) of lesion to the liver or bile, and image noise were assessed and compared between VNE and TNE images. The effective dose and size-specific dose estimate(SSDE) were also calculated. Results The mean CT values of the lesions measured on VNE images declined significantly compared with those measured on TNE images(164.51±102.13 vs. 290.72±197.80 HU, P<0.001), so did the lesion-to-liver CNR(10.80±11.82 vs.18.81±17.06, P<0.001) and the lesion-to-bile CNR(17.24±14.41 vs. 21.32±17.31, P<0.001). There was no significant difference in size of lesions area between VNE and TNE images(0.69±0.88 vs. 0.72±0.85 cm2, P=0.062). Compared to the 128 lesions found in TNE images, VNE images showed the same density in 30(23.4%) lesions, lighter density in 88(68.8%) lesions, while failed to show 10(7.8%) lesions, and showed the same size in 61(47.7%) lesions and smaller size in 57(44.5%)lesions. The CT cutoff values of lesion and size were 229.21 HU and 0.15 cm2, respectively. The total effective dose for triple phase scan protocol with TNE images was 19.51±7.03 mS v, and the SSDE was 39.84±11.10 mGy. The effective dose for dual phase scan protocol with VNE images instead of TNE images was 13.29±4.89 m Sv, and the SSDE was 27.83±9.99 mGy. Compared with TNE images, the effective dose and SSDE of VNE images were down by 32.05%±3.69 % and 30.63%±2.34 %, respectively. Conclusions Although the CT values and CNR of the lesions decreased in VNE images, the lesions of which attenuation greater than 229.21 HU and size larger than 0.15 cm^2 could be detected with good reliability and obvious dose reduction. There was good consistency in the size of stones and calcifications in hepatobiliary system between VNE images and TNE images, which ensured the possibility of the clinical application of VNE images.

Future of cardiac computed tomography

Coronary computed tomography angiography(CCTA)has become an integral tool in the noninvasive diagnostic workup of patients with suspected coronary artery disease in both elective and emergency settings. Today, it represents a mature technique providing accurate, non-invasive morphological assessment of the coronary arteries and atherosclerotic plaque burden. Iterative reconstruction algorithms, low kV imaging, and single-heart beat acquisitions hold promise to further reduce dose requirements and improve the safety and robustness of the technique in several circumstances including imaging of heavily calcified vessels, patients with morbid obesity or irregular heart rates, and assessment in the emergency setting. However, it has become clear over recent years that cardiac radiologists need to take further steps towards the development and integration of functional imaging with morphological CCTA assessment to truly provide a comprehensive evaluation of the heart. Computed tomography myocardial perfusion imaging, including both dynamic and static dual-energy approaches, has demonstrated the ability to directly assess and quantify myocardial ischemia with simultaneous CCTA acquisition with a reasonable contrast medium volume and radiation dose delivered to the patient. In order to promote CCTA in the clinical and research environments, radiologists should prepare to embrace the change from morphological to functional imaging, furnishing all the necessary resources and information to referring clinicians.

DECT定量参数预测胃癌淋巴结转移的临床价值探析

目的:探讨胃癌原发灶双能量计算机体层成像(dual-energy computed tomography,DECT)定量参数对术前淋巴结转移(lymph node metastasis,LNM)的预测价值。方法:回顾并分析2020年7月—2022年1月福建医科大学省立临床医学院福建省立医院203例经术后病理学检查确诊为胃腺癌患者的临床病理及影像学资料,根据淋巴结术后病理学检查结果,将其分为淋巴结转移组[LNM(+),130例]与非转移组[LNM(-),73例]。由2名医师采用双盲方式测量并计算每例患者病灶动脉期、静脉期及延迟期标准化碘浓度(normalized iodine concentration in arterial/venous/delay phase,nICA/nICV/nICD)及相应能谱曲线(40~110 keV)斜率k值,进行单因素分析。将P<0.05的指标纳入多因素logistic回归分析中构建预测模型。绘制受试者工作特征(receiver operating characteristic,ROC)曲线评价预测模型的诊断效能,并使用DeLong检验比较各曲线间差异。结果:原发灶最大径、T分期及Lauren分型在两组间差异均有统计学意义(P<0.05);DECT定量参数中,LNM(+)组的nICV、nICD、kA、kV及kD均大于LNM(-)组(P<0.05),而nICA在两组间差异无统计学意义;多因素logistic回归分析示,T分期、Lauren分型、nICV和kV是胃癌LNM的独立危险因素(P<0.05);纳入T分期、Lauren分型和nICV的预测模型1和纳入T分期、Lauren分型和kV的预测模型2术前诊断LNM对应的曲线下面积(area under curve,AUC)分别为0.839和0.858,两者差异无统计学意义(P>0.05)。结论:联合DECT定量参数的预测模型对胃癌术前LNM状态具有较高的诊断效能,其中,静脉期DECT定量参数较其余期相更具诊断价值。

Application of an Advanced Image-Based Virtual Monoenergetic Reconstruction of Dual Source Dual-Energy CT Data at Low keV Increases Image Quality for Esophageal Cancer Patients Imaging

Purpose: To explore the significance of dual-source computed tomography (DECT) virtual monoenergetic reconstructions technology in improving the imaging quality of esophageal cancer patients. Materials and methods: 68 patients with clinically suspected esophageal cancer (all confirmed by pathology) were collected. Routine plain scan was performed with SIEMENS Force dual-energy CT and then dual-phase scans were performed. The venous phase images were respectively subjected to traditional virtual monoenergetic reconstructions (Mono_E) and new generation virtual monoenergetic reconstructions (Mono+). Mono_E 55 keV and Mono+ 55 keV virtual single-energy images were obtained respectively. The signal-to-noise ratio (SNR) of normal esophageal tissue and esophageal cancer lesions, noise and contrast noise ratio (CNR tumor) of normal esophageal tissue and esophageal cancer lesions were compared among 100 kV images, Mono_E images and Mono+ images. At the same time, two imaging physicians read the films and scored the images of each group by using a 5-point scoring method. Results: Mono+ 55 keV images, SNR, SNRtumor, noise and CNRtumor were statistically different from those of 100 kV images and Mono_E images (P < 0.05). And Mono+ 55 keV images also had the highest subjective score, with statistical significance (P 55 keV images had the best quality. Conclusion: The new generation of virtual monoenergetic reconstructions post-processing (Mono+) could reduce image noise and improve the contrast between esophageal cancer lesions and normal esophageal tissues, which was of great significance to improve the imaging quality of esophageal cancer patients and improve the early detection rate of esophageal cancer.

双源双能量CT图像优化技术对肺动脉成像图像质量的影响

目的定量评价双源双能量CT最佳单能量成像技术及非线性融合技术对肺动脉图像质量影响。方法回顾性分析28例肺动脉栓塞患者影像学资料,经处理获得100 kVp图像(A组)、140 kVp图像(B组)、非线性融合图像(C组)及最佳单能量图像(D组),分别测量4组图像中肺动脉栓子的CT值、噪声及邻近血管CT值,计算信噪比(SNR)及对比噪声比(CNR),进行相应统计学分析。结果4组图像间栓子CT值差异无统计学意义;噪声、CNR、SNR等参数差异具有统计学意义(P<0.05);其中非线性融合图像质量最佳;最佳单能量图像较常规图像也具有一定优势。结论非线性融合技术及最佳单能量成像技术可以优化肺动脉图像成像质量。

ssDECT增强扫描碘浓度鉴别良恶性浆膜腔积液

目的探讨单源双能量CT增强扫描三期碘浓度对良恶性浆膜腔积液的鉴别诊断价值。方法回顾性分析我院行单源双能量CT增强扫描、并经穿刺脱落细胞学检査证实的浆膜腔积液患者65例,其中良性积液23例,恶性积液42例。采用单源双能量CT综合分析平台,在常规混合能量扫描下分别测量计算平扫及动脉期、静脉期、延迟期的标准化CT值(NCTval;NCTval_N、NCTval_A、NCTval_P、NCTval_D);并计算三期标准化CT值强化程度(NCT;NCT_A、NCT_P、NCT_D)。采用能谱分析软件于碘(水)图像上分别测量并计算平扫及增强三期标准化碘浓度(NIC;NIC_N、NIC_A、NIC_p、NIC_D);计算增强三期碘浓度强化程度(IC;IC_A、IC_P、IC_D)。比较良恶性浆膜腔积液的NCTval、NCT、NIC、1C,并进行ROC曲线分析计算各参数诊断良恶性浆膜腔积液的敏感度和特异度。结果增强三期良、恶性浆膜腔积液NCTval、NCT差异均无统计学意义(P均>0.05),而NIC、IC差异均有统计学意义(P均<0.05)。增强三期中IC_D的曲线下面积最大(0.82),当阈值为0.04时,敏感度、特异度分别为76.2%,69.6%。结论单源双能量CT增强扫描碘浓度可为鉴别良恶性浆膜腔积液提供一种敏感、有效的方法。

DECT成像对痛风患者不同临床时期尿酸盐沉积量与尿酸值相关性的研究

目的探讨双源CT双能量（DECT）成像技术对痛风患者不同临床时期尿酸盐结晶与血尿酸的关系，进而评估DECT成像在痛风筛查中的应用价值。方法回顾性分析120例高尿酸血症或痛风患者的DECT成像特点及临床资料，根据临床分期分为两组，男92例，女28例；对照组为非痛风患者30例，男26例，女4例。所有病例手、足均行DECT非增强扫捕，薄层再组后将原始数据传至MMWP：工作站选择Dual Energy GOUT软件，进行影像后处理，比较痛风患者两期尿酸盐沉积的差异与尿酸值相关性，以及DECT检测尿酸盐沉积部位与临床评估的差异。采用t检验、x2检验、Fisher精确概率进行统计学分析。结果：组性别及年龄比较，差异无统计学意义（P年龄=0．236，P性别=0．613，P〉0．005）。高尿酸组尿酸盐沉积量明显高于尿酸正常组，两组有显著统计学意义（P=0．00013，P〈0．001）；痛风组检出率与对照组相比。差异有显著统计学意义（P=0．00015，P〈0．001）。结论DECT成像技术对尿酸盐结晶沉积有很好的显示能力，对高尿酸血症、痛风早期、疑似痛风患者均有较高的检出率，可作为痛风筛选的常规检查项目，具有较高的临床应用价值。

双能CT定量参数对甲状腺乳头状癌颈侧区淋巴结转移的预测价值

目的探讨双能CT(DECT)定量参数对甲状腺乳头状癌(PTC)颈侧区淋巴结转移(LLNM)的预测价值。方法回顾性分析216例(LLNM组174例,非LLNM组42例)经手术病理证实的PTC患者DECT影像资料。比较两组间DECT定量参数差异,包括平扫、动脉期和静脉期碘浓度(IC)、有效原子序数(Zeff)、能谱曲线斜率(λHU)、标准化IC(NIC)和标准化Zeff(NZeff)。将差异有统计学意义的参数纳入二元Logistic回归分析LLNM的独立预测因子。通过受试者工作特征曲线(ROC)评估独立预测因子及其联合对LLNM的预测效能。结果与非LLNM组比较,LLNM组具有更低的平扫NIC(Z=-2.279,P=0.023),更高的动脉期IC、NIC、NZeff、λHU和更高的静脉期IC、NIC、Zeff、λHU(P均<0.05)。二元Logistic回归分析显示,平扫NIC(P=0.006)和静脉期NIC(P=0.002)是LLNM的独立预测因子,其联合模型的预测效能最高,曲线下面积(AUC)为0.672(95%CI:0.605~0.734),敏感度63.79%,特异度66.67%;其次是静脉期NIC(AUC=0.634)和平扫NIC(AUC=0.613)模型。结论DECT定量参数可在一定程度上辅助预测PTC患者有无LLNM。

Complementary comments on diagnosis,severity and prognosis prediction of acute pancreatitis

The radiological differential diagnosis of acute pancreatitis includes diffuse pancreatic lymphoma,diffuse autoimmune pancreatitis and groove located mass lesions that may mimic groove pancreatitis.Dual energy computed tomography and diffusion weighted magnetic resonance imaging are useful in the early diagnosis of acute pancreatitis,and dual energy computed tomography is also useful in severity assessment and prognosis prediction.Walled off necrosis is an important complication in terms of prognosis,and it is important to know its radiological findings and distinguish it from pseudocyst.

基于双能量CT中双能量指数、原子序数结合能谱曲线斜率对于鉴别泌尿系结石成分的价值研究

目的:评估双能量计算机体层扫描(DECT)的双能量指数(DEI)、有效原子序数(Zeff)结合能谱曲线斜率在鉴别患者泌尿系结石成分的价值。方法:收集2019年10月至2022年10月在南通市海门区人民医院就诊的111例泌尿系结石患者的临床及DECT影像资料。所有患者泌尿系结石直径均>5 mm,所有患者的离体结石均经红外光谱分析确定结石成分。分别计算DEI、Zeff、能谱曲线斜率及三者结合对于鉴别泌尿系结石成分的准确率、灵敏度、特异度等。结果:111例患者中草酸钙结石75例(占67.57%),羟基磷灰石15例(占13.51%),尿酸结石21例(占18.92%),未发现胱氨酸等其他类型结石。3种类型结石的CT值(F=487.691,P<0.001)、DEI(F=395.553,P<0.001)、Zeff(F=818.689,P<0.001)和能谱曲线斜率(H=19.615,P<0.001)比较的差异均有统计学意义。DEI、Zeff和能谱曲线斜率对鉴别泌尿系结石成分的总准确率分别为87.39%(97/111)、84.68%(94/111)和81.98%(91/111)。DEI、Zeff和能谱曲线分别对草酸钙结石、羟基磷灰石及尿酸结石诊断准确率均为80%~100%。DEI、Zeff结合能谱曲线斜率对鉴别泌尿系结石成分的总准确率为94.59%(105/111)。DEI、Zeff结合能谱曲线斜率对草酸钙结石、羟基磷灰石及尿酸结石诊断的准确性分别为94.59%、94.59%和100%。结论:与DECT的单个指标相比,DEI、Zeff结合能谱曲线斜率对鉴别泌尿系结石成分显示出更好的诊断准确率。

4D-DECT对甲状旁腺腺瘤的诊断价值

目的:探讨甲状旁腺腺瘤(PA)的4D-DECT影像特征及物质成分信息,评价其定位及定性诊断价值。资料和方法:回顾性分析经手术及病理证实的53例PA患者的临床资料及4D-DECT影像资料,逐一观察并记录CT征象,分别对病变与邻近组织的CT衰减值(HU)、碘浓度、Rho、Z值及DEI进行测定及比较分析。结果:53例患者中,52例(98.11%)为单发病灶,1例(1.89%)为多发病灶,共计病灶54枚,其中32枚(59.26%)位于气管-食管旁沟,10枚(18.52%)为异位腺瘤,22枚(40.74%)可见“短线征”,14枚(25.93%)可见“极血管征”;动脉期(90 kV)图像PA与甲状腺CT值无明显差异,平扫、动脉期(混合0.5、150 kV)及静脉期(90 kV、混合0.5、150 kV)图像中PA、甲状腺及淋巴结CT值均有差异。动脉期及静脉期淋巴结的碘浓度、Z值及DEI明显低于PA及甲状腺,静脉期PA的碘浓度、Z值及DEI明显低于甲状腺;动脉期及静脉期甲状腺Rho明显高于PA,动脉期PA的Rho明显高于淋巴结。结论:4D-DECT可较好地显示PA的影像学特征,还可以提供病变的碘浓度等多种物质成分信息,有助于提高PA的诊断准确性。

双能CT在克罗恩病中的研究进展

克罗恩病(CD)是一种慢性、反复发作的炎症性肠病,需要长期监测药物治疗反应。双能CT(DECT)不仅能提供形态学特征,还可生成常规CT影像、虚拟单能谱影像、碘密度图等不同的能谱影像来提供定量特征,实现无创、准确监测。DECT已逐渐应用于CD的诊断与鉴别诊断、活动性及严重程度评估、疗效评估与预后预测等方面。就DECT在CD中的应用进展予以综述。

肺癌与肺癌共病的CT研究进展

肺癌发生发展、临床决策及预后与肺癌共病密切相关,而肺癌及其治疗对肺癌共病发生发展也发挥着不可忽视的作用。因此,肺癌与肺癌共病的相互联系值得深入探索。CT可以对肺癌及肺癌共病进行定性诊断,定量评估其严重程度、疗效及预后等,为揭示两者相互联系提供新的方式。就肺癌共病对肺癌的影响、肺癌及其治疗对肺癌共病的影响、CT在肺癌及肺癌共病中应用等方面的研究进展予以综述。