The application study of dual-energy CT nonlinearblending technique in pulmonary angiography

Objective This study aimed to explore the feasibility of enhancing image quality in computed tomography(CT) pulmonary angiography (CTPA) and reducing radiation dose using the nonlinear blending (NLB)technique of dual-energy CT.Methods A total of 61 patients scheduled for CTPA were enrolled, and 30 patients underwent dual-energyscanning. Nonlinear blending images (NLB group) and three groups of linear blending images (LB group,80 kV group, and 140 kV group) were reconstructed after scanning;31 patients underwent single-energyscanning (120 kV group). The CT values and standard deviations of the pulmonary trunk, left and rightpulmonary arteries, and ipsilateral back muscle at the bifurcation level of the left and right pulmonaryarteries were measured. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the fivegroups were calculated. The subjective image quality of the five groups was assessed. The radiation dosesof the dual- and single-energy groups were recorded and calculated.Results The CNR and SNR values of blood vessels in the NLB group were significantly higher than thosein the LB, 140 kV, and 80 kV groups (CNR of pulmonary artery trunk: t = 3.50, 4.06, 7.17, all P < 0.05;SNRof pulmonary trunk: t = 3.76, 4.71, 6.92, all P < 0.05). There were no statistical differences in the CNR andSNR values between the NLB group and 120 kV group (P > 0.05). The effective radiation dose of the dualenergygroup was lower than that of the single-energy group (t = –4.52, P < 0.05). The subjective scores ofimages in the NLB group were the highest (4.28 ± 0.74).Conclusion The NLB technique of dual-energy CT can improve the image quality of CTPA and reducethe radiation dose, providing more reliable imaging data for the clinical diagnosis of pulmonary embolism.

Diagnostic Value of Dual-Energy CT in Differentiating Malignant and Benign Thyroid Nodules: A Systematic Review and Meta-Analysis

Objectives: To evaluate the diagnostic performance of the quantitative iodine parameters, including Iodine Concentration (IC), Normalized Iodine Concentration (NIC), and λHU, in distinguishing malignant and benign thyroid nodules. Methods: Relevant studies were searched from Web of Science, PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure database and other complementary sources from inception to May 20, 2020. Study selection, data extraction, quality assessment, and data analyses were performed following the Cochrane standards and the PRISMA-DTA guideline. Results: Eight studies were included (595 patients with 737 thyroid nodules). The pooled sensitivity, specificity and summary diagnostic odds ratio of IC were 79% (95% CI: 69% - 86%), 76% (95% CI: 65% - 84%) and 11 (95% CI: 5 - 27) respectively;those of NIC were 78% (95% CI: 70% - 85%), 80% (95% CI: 74% - 85%) and 15 (95% CI: 9 - 24) respectively;those of λHU were 80% (95% CI: 71% - 87%), 77% (95% CI: 70% - 83%) and 14 (95% CI: 8 - 24) respectively. Conclusion: DECT can be a potential evaluation tool for thyroid nodules. The NIC may be the most sensitive iodine parameter and could be comparable between different DECT machines in thyroid nodule assessment.

Value of dual-energy CT virtual noncalcium in the diagnosis of sacroiliac joint bone marrow edema

Objective:To explore the clinical value of dual energy CT(DECT)virtual noncalcium(VNCa)in the diagnosis of sacroiliac joint bone marrow edema(BME).Methods:A collection of 45 patients(21 males,24 females,and an average age of 34 years)who underwent MRI and DECT(Siemens Somatom definition force)examinations for the sacroiliac joints in our hospital from January 2019 to August 2020.After the DECT scan,the bone marrow pseudo-color map was obtained after VNCa processing.The bone marrow pseudo-color map was evaluated by two physicians.Take MRI test results as the gold standard,the application value of DECT VNCa technology in the diagnosis of sacroiliac joint BME was analyzed.Results:The positive predictive value(PPV),negative predictive value(NPV),sensitivity(Sen),specificity(Spe)and accuracy(Acc)of the qualitative diagnosis of iliac bone and sacral BME with DECT VNCa technology was:80.6%,85.2%,78.4%,86.8%,83.3%and 100%,64.9%,32.5%,100%,70.0%,respectively.The area of edema displayed by quantitative measurement of DECT VNCa image is smaller than the area measured by MRI image.The VNCa CT value(-71.66±72.97Hu)of the iliac edema area was higher than that of the non-edema area(-90.27±65.85Hu),and the VNCa CT value of the sacral edema area(-62.90±46.87Hu)was higher than that of the non-edema area(-101.08±134.02Hu),the best cut-off values(Cut-off values)for the quantitative diagnosis of iliac bone and sacral BME by VNCa are-66.40Hu and-50.60Hu,respectively.The curve of the receiver operating characteristic(ROC)of the iliac bone and sacrum area under the cure(AUC)is 0.720 and 0.706 respectively.There is a moderate negative correlation between the VNCa CT values of the ilium and sacrum in the edema area and the conventional CT values.Conclusion:The DECT VNCa technique has certain effectiveness in the diagnosis of sacroiliac joint BME,and its effectiveness in the diagnosis of ilium BME is better than sacrum.

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.

An experimental study of dual-energy CT imaging using synchrotron radiation

The measurement of electron density is important for medical diagnosis and charged particle radiotherapy treatment planning.Traditionally,electron density is obtained by CT imaging using the relationship between CT-number and electron densities established beforehand.However,the measurement is not accurate due to the beam hardening effect.In this paper,we propose a simple and practical electron density acquisition method based on dual-energy CT technique.For each sample,the CT imaging is conducted using two selected X-ray energy from synchrotron radiation.A post-processing dual-energy reconstruction method is used.Linear attenuation coefficients of the scanned samples are obtained by FBP reconstruction.The effective atomic number and electron density are got by solving the dual-energy simultaneous equations.Different phantoms and breast tissues were scanned in this experimental study under 10 keV and 30 keV monochromatic X-rays.The distribution of effective atomic numbers and electron densities of the scanned phantoms were obtained by Dual-energy CT image reconstruction,which agrees well with the theoretical values.Compared with conventional methods,the measurement accuracy is greatly improved, and the measurement error is reduced to about 1%.This experimental study demonstrates that DECT imaging based on synchrotron radiation source is applicable to medical diagnosis for quantitative measurement with high accuracy.

Clinical Value of Dual-energy CT in Detection of Pancreatic Adenocarcinoma: Investigation of the Best Pancreatic Tumor Contrast to Noise Ratio

Objective To quantitatively compare and determine the best pancreatic tumor contrast to noise ratio (CNR) in different dual-energy derived datasets. Methods In this retrospective, single center study, 16 patients (9 male, 7 female, average age 59.4±13.2 years) with pathologically diagnosed pancreatic cancer were enrolled. All patients received an abdominal scan using a dual source CT scanner 7 to 31 days before biopsy or surgery. After injection of iodine contrast agent, arterial and pancreatic parenchyma phase were scanned consequently, using a dual-energy scan mode (100 kVp/230 mAs and Sn 140 kVp/178 mAs) in the pancreatic parenchyma phase. A series of derived dual-energy datasets were evaluated including non-liner blending (non-linear blending width 0-500 HU; blending center -500 to 500 HU), mono-energetic (40-190 keV), 100 kVp and 140 kVp. On each datasets, mean CT values of the pancreatic parenchyma and tumor, as well as standard deviation CT values of subcutaneous fat and psoas muscle were measured. Regions of interest of cutaneous fat and major psoas muscle of 100 kVp and 140 kVp images were calculated. Best CNR of subcutaneous fat (CNR F ) and CNR of the major psoas muscle (CNR M ) of non-liner blending and mono-energetic datasets were calculated with the optimal mono-energetic keV setting and the optimal blending center/width setting for the best CNR. One Way ANOVA test was used for comparison of best CNR between different dual-energy derived datasets. Results The best CNR F (4.48±1.29) was obtained from the non-liner blending datasets at blending center -16.6±103.9 HU and blending width 12.3±10.6 HU. The best CNR F (3.28±0.97) was obtained from the mono-energetic datasets at 73.3±4.3 keV. CNR F in the 100 kVp and 140 kVp were 3.02±0.91 and 1.56±0.56 respectively. Using fat as the noise background, all of these images series showed significant differences (P<0.01) except best CNR F of mono-energetic image sets vs. CNR F of 100 kVp image (P=0.460). Similar results were found using muscle as the noise background (mono-energetic image vs. 100 kVp image: P=0.246; mono-energetic image vs. non-liner blending image: P=0.044; others: P<0.01). Conclusion Compared with mono-energetic datasets and low kVp datasets, non-linear blending image at automatically chosen blending width/window provides better tumor to the pancreas CNR, which might be beneficial for better detection of pancreatic tumors.

Application of Dual-Energy CT Non-Linear Fusion Technology in Improving CTA Image Quality of Renal Cancer

Objective: To explore the significance of dual-energy CT non-linear fusion technique in improving the quality of CTA image of renal cancer. Methods: The CTA images of 100 patients who had been confirmed by pathology as renal cancer were collected and were randomly divided into experimental group and control group with 50 cases respectively. The two groups of patients were treated with iodine concentration of 300 mg/ml and 350 mg/ml non-ionic contrast agent, with a dosage of 1.5 ml/kg and an injection rate of 4 ml/s. The contrast agent intelligently tracking method was adopted bolus. The control group used the conventional CTA scanning, with a reference tube voltage/tube current of 100 kv/ref150 mas. The experimental group adopted the double energy scanning, with ball tube A and ball tube B. The reference tube voltage/tube current was 100 kv/ref250 mas and sn150 kv/ref125 mas respectively. The images of the experimental group were non-linear fused to obtain the Mono+ 55 kev single-energy images. The CT value, SNR contrast ratio of the abdominal aorta, renal artery and tumor tissue of the experimental group images and the 100 KV images and the Mono+ 55 kev images of the control group were compared. The objective evaluation and subjective evaluation of the image quality of the three groups of images was performed. Results: The results showed that the 100 kV images of the experimental group were statistically different from those of the control group (P05) in CT value, SNR and CNR (P 0.05). And there was no statistically significant difference between the non-linear fusion single-energy Mono+ 55 kev images and the control group images in CT value, SNR and CNR (P > 0.05). The subjective evaluation of image quality showed that there was no significant difference between Mono+ 55 kev images and control group images, and the quality of Mono+ 55 kev images was higher than that of experimental group 100 kV images. Conclusion: The dual-energy CT non-linear fusion technique can improve the quality of CTA image in patients with renal cancer, and it is possible to obtain high quality CTA images with low iodine concentration contrast agent.

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.

Significance of an Advanced Image-Based Virtual Monoenergetic Reconstruction of Dual Source Dual-Energy CT Data at Low keV Increases Image Quality for Portal Vein System of Pancreatic Cancer Patients

Purpose: To explore the significance of dual-source computed tomography (DECT) virtual monoenergetic reconstructions technology in improving image quality for portal vein system of pancreatic cancer patients. Materials and methods: 47 patients with clinically suspected pancreatic cancer (all confirmed by pathology) were collected. Routine plain scan was performed with Siemens Force dual-source dual-energy CT followed by 3 scans respectively carried out in arterial phase, portal phase and delayed phase. Traditional virtual monoenergetic reconstructions (Mono_E) and new generation of virtual monoenergetic reconstructions (Mono+) were respectively performed on portal vein images to obtain virtual single energy images including Mono_ E70 keV, Mono_E 55 keV and Mono+ 70 keV and Mono+ 55 keV. The signal-to-noise ratio (SNR) and noise of portal vein, normal pancreatic tissues and pancreatic lesions of 100 kV, Mono_E and Mono+ images were compared. In addition, the contrast noise ratio of portal vein and lesions as well as pancreatic tissues and lesions (CNR PV, CNRtumor) were also compared. At the same time, two imaging physicians with rich clinical experiences read the films and scored the images of each group by using the 5-point scoring method. Results: Mono+ 55 keV images including SNRpv, SNRpanc, SNRtumor, Noise, CNRpv, CNRtumor were statistically different from 100 KV images and Mono_E images (P < 0.05). As for the subjective score, Mono+ 55 keV image score also had the highest score, which had statistical significance (P < 0.05). The results showed that Mono+ 55 keV images had the best quality. Conclusion: The new generation of virtual Mono+ post-treatment can reduce image noise. Low energy Mono+ images can improve the contrast between pancreatic cancer lesions and portal of pancreatic cancer patients.

Gold as a Potential Contrast Agent for Dual-Energy CT

Purpose: The K-edge of gold (81 keV) is located within the energy range of diagnostic CT. This might be advantageous for material differentiation in dual-energy CT (DECT). The aim of this in vitro study was to compare the differentiation between iodine or gold and body tissues using DECT at different kV spectra. Methods and Materials: A water filled tank phantom containing specimens with iodine (iopamidol), gold (sodium aurothiomalate), compact bone (compact porcine bone) and porcine muscle was scanned using a dual source CT (Definition, Siemens Healthcare). Consecutive scans were performed at 80 kVp, 100 kVp, 120 kVp and 140 kVp with constant mAs settings. The mean attenuation values of the specimens were measured, and differences in calculated dual-energy ratios (DEratio) between body tissues and iodine or gold were determined for different DE spectra. Results: The attenuation of gold increased compared to 80 kVp at higher kVp-settings, while the attenuation of all other specimens decreased. The calculated DEratios at 80/100 kVp, 80/120 kVp and 80/140 kVp were 1.31, 1.62 and 1.91 for iodine, 0.89, 0.88 and 0.92 for gold, 1.20, 1.39 and 1.45 for compact bone, 1.01, 1.03 and 1.08 for muscle. The differences between the DEratios 80/100 kVp, 80/120 kVp and 80/140 kVp were 0.11, 0.23 and 0.46 for iodine and bone, 0.31, 0.51 and 0.53 for gold and bone, 0.29, 0.59 and 0.83 for iodine and muscle, 0.12, 0.15 and 0.16 for gold and muscle. Conclusion: DEratio of gold remains relatively stable along the energy spectrum of diagnostic CT and allows a reliable material differentiation between gold and bone already at contiguous low tube voltage settings (80 kV and 100 kV). Thus, gold might have a potential as a contrast agent for DECT.

Characterization of tumors of jaw:Additive value of contrast enhancement and dual-energy computed tomography

BACKGROUND Currently,the differentiation of jaw tumors is mainly based on the lesion’s morphology rather than the enhancement characteristics,which are important in the differentiation of neoplasms across the body.There is a paucity of literature on the enhancement characteristics of jaw tumors.This is mainly because,even though computed tomography(CT)is used to evaluate these lesions,they are often imaged without intravenous contrast.This study hypothesised that the enhancement characteristics of the solid component of jaw tumors can aid in the differentiation of these lesions in addition to their morphology by dual-energy CT,therefore improving the ability to differentiate between various pathologies.AIM To evaluate the role of contrast enhancement and dual-energy quantitative parameters in CT in the differentiation of jaw tumors.METHODS Fifty-seven patients with jaw tumors underwent contrast-enhanced dual-energy CT.Morphological analysis of the tumor,including the enhancing solid component,was done,followed by quantitative analysis of iodine concentration(IC),water concentration(WC),HU,and normalized IC.The study population was divided into four subgroups based on histopathological analysis-central giant cell granuloma(CGCG),ameloblastoma,odontogenic keratocyst(OKC),and other jaw tumors.A one-way ANOVA test for parametric variables and the Kruskal-Wallis test for nonparametric variables were used.If significant differences were found,a series of independent t-tests or Mann-Whitney U tests were used.RESULTS Ameloblastoma was the most common pathology(n=20),followed by CGCG(n=11)and OKC.CGCG showed a higher mean concentration of all quantitative parameters than ameloblastomas(P<0.05).An IC threshold of 31.35×100μg/cm^(3) had the maximum sensitivity(81.8%)and specificity(65%).Between ameloblastomas and OKC,the former showed a higher mean concentration of all quantitative parameters(P<0.001),however when comparing unilocular ameloblastomas with OKCs,the latter showed significantly higher WC.Also,ameloblastoma had a higher IC and lower WC compared to“other jaw tumors”group.CONCLUSION Enhancement characteristics of solid components combined with dual-energy parameters offer a more precise way to differentiate between jaw tumors.

术中滑轨CT辅助在经皮骶髂关节螺钉治疗骨盆后环损伤中的应用

目的:比较术中滑轨CT联合C形臂X线机辅助与单纯使用C形臂X线机辅助透视下经皮骶髂关节螺钉治疗骨盆后环损伤临床疗效。方法:自2018年12月至2022年2月收治76例骨盆后环损伤患者,其中,C形臂联合滑轨CT辅助下行内固定治疗39例为CT组,男23例,女16例,年龄(44.98±7.33)岁;仅在C形臂透视下行内固定治疗37例为C形臂组,男24例,女13例,年龄(44.37±10.82)岁。合并有前环骨折患者42例,均采用经皮髂前下棘内置外固定架(internal fixation,INFIX)或耻骨上支螺钉固定骨盆前环。术后比较两组随访时间、置钉时间、并发症。比较两组Matta复位评价、Majeed疗效评价、CT分级及二次手术翻修率。结果:CT组置钉时间(32.63±7.33) min,短于C形臂组(52.95±10.64) min(t=-9.739,P<0.05)。CT组随访时间(11.97±1.86)个月,C形臂组(12.03±1.71)个月,两组比较差异无统计学意义(P>0.05)。两组术后并发症发生比较,差异无统计学意义(χ~2=0.159,P>0.05)。CT组Matta复位评价结果(Z=2.79,P<0.05)、Majeed疗效评价结果(Z=2.79,P<0.05)、CT分级(Z=2.83,P<0.05)均优于C形臂组。CT组二次手术翻修率低于C形臂组(χ~2=5.641,P<0.05)。结论:术中滑轨CT联合C形臂辅助下经皮骶髂关节螺钉置入手术与传统C形臂透视相比,具有手术时间短、准确度及安全性高、术后二次翻修率显著下降等特点,是重建骨盆骨折后环稳定性的有效方法之一。

CT血管成像对ACI患者颈动脉狭窄程度及侧支循环的价值研究

目的分析、探究CT血管成像技术在ACI患者颈动脉狭窄、侧支循环等病情诊断方面的成效。方法对我院2021.3-2022.3月期间收治的100例急性脑梗死(ACI)患者一般病理资料进行回顾性分析,以数字减影血管造影(DSA)结果为诊断金标准,对CT血管成像技术(CTA)的诊断价值进行分析,以临床出具的数字减影血管造影(DSA)结果为金标准,分析CT血管成像技术(CTA)在临床上的诊断价值,评估此技术在临床诊断中的效能。结果与临床金标准相比,CTA诊断技术具有较高的临床评估价值[Kappa>0.8~1.0,曲线下面积(AUC)>0.9,P<0.01];CTA诊断技术在评估颈动脉狭窄程度等方面与临床金标准具有一定的一致性[Kappa>0.6~0.8,曲线下面积(AUC)>0.7~0.9,P<0.01];而在评估侧支循环临床诊断中,CTA诊断技术与临床金标准具有一致性,具有较高的评估价值[Kappa>0.8~1.0,曲线下面积(AUC)>0.9,P<0.01]。结论以临床“金标准”的诊断结果为依据分析,CTA诊断技术能够对ACI患者出现病变的血管形态及侧支循环状态等进行全面的评估,CTA诊断结果可为治疗工作提供准确性相对较高且客观的医学依据,确实是评估ACI患者颈动脉狭窄程度、侧支循环状态的可靠办法;而与DSA技术相比,CTA与之具有较高的一致性,说明在病情发作早期为ACI患者实施CTA检查可获悉颈动脉的狭窄及侧支循环状态,有利于改善患者群体的预后。

胸腹部平扫CT值用于机会性筛查骨质疏松的可行性

目的:基于定量CT(QCT)探讨胸部常规kVp平扫和腹部能谱GSI平扫下椎体CT值用于机会性筛查骨质疏松的可行性。方法:前瞻性收集接受胸腹部平扫的患者431例,胸部CT扫描采用常规120 kVp,腹部扫描采用能谱(GSI)模式。对胸腹部扫描重叠的T11~L1椎体进行分析。使用QCT骨密度测量工作站测得胸部常规120 kVp下T11~L1椎体的骨密度(BMD),同时分别测量胸部120 kVp与腹部GSI扫描70 keV单能量下T11~L1椎体的CT值。采用组内相关系数(ICC)评估数据测量的一致性,Spearman相关性检验分析椎体BMD值与CT值之间的相关性。不同椎体间CT值差异采用Friedman秩和检验。参考QCT诊断标准,将椎体分为骨质疏松、骨量减少和骨量正常组,采用Kruskal-Wallis比较三组间及组内CT值差异。组内120 kVp-CT值和GSI-CT值采用Wilcoxon秩和检验。以T11~L1椎体BMD均值行骨质状态判定,采用受试者操作特征(ROC)曲线分析椎体CT值评估骨质状态的诊断效能。结果:椎体BMD与120 kVp-CT值和GSI-CT值均呈正相关(r=0.976、0.963,P<0.001)。120 kVp和GSI下T11~L1椎体CT值依次为T11[144.00(72.00)、158.00(79.00)]、T12[137.00(67.00)、150.00(76.00)]、L1[128.00(67.00)、137.00(74.00)],不同椎体及椎体内差异均有统计学意义(P<0.001)。431例患者共1293个椎体,骨量正常组椎体496个、骨量减少组椎体415个、骨质疏松组椎体382个。120 kVp和GSI下骨量正常、骨量减少和骨质疏松组椎体CT值依次为[181.50(43.67)、199.65(48.57)]、[132.20(18.50)、144.00(23.00)]和[87.75(22.20)、93.30(27.20)],不同骨质状态组间椎体CT值差异有统计学意义(P<0.05),且各组组内椎体GSI-CT值均高于椎体120 kVp-CT值(P<0.05)。120 kVp-CT值与GSI-CT值诊断骨量减少的AUC分别为0.976、0.967,差异无统计学意义(P=0.0937);诊断骨质疏松的AUC均为1.000,差异无统计学意义(P=1.000)。结论:胸部常规120 kVp及腹部GSI平扫CT值均可用于机会性筛查骨质疏松,诊断效能良好。

颅脑CT灌注成像及磁共振成像在脑梗死患者中的应用

目的分析颅脑CT灌注成像及磁共振成像对脑梗死患者的诊断价值。方法选取2022-03—2023-05在江苏省中西医结合医院就诊的80例疑似脑梗死患者为研究对象,对比分析GE Revolution CT颅脑灌注成像、磁共振成像及联合检查的敏感性、特异性、准确性,制作3种影像学检查的受试者工作特征(ROC)曲线。结果根据患者病情和临床综合诊断确诊,80例疑似脑梗死患者中脑梗死阳性69例(86.25%),脑梗死阴性11例(13.75%)。3种影像学检查方法的灵敏度、准确率比较,从高到低依次为联合检查、GE Revolution CT颅脑灌注成像检查、磁共振成像检查,差异有统计学意义(P<0.05)。GE Revolution CT颅脑灌注成像检查、磁共振成像检查、联合检查诊断脑梗死的ROC曲线下面积(AUC)分别为0.8109、0.7688、0.8682。结论GE Revolution CT颅脑灌注成像与磁共振成像检查的联合应用,有利于提高脑梗死患者诊断的灵敏度、准确率及AUC水平。

优化双下肢动脉能谱CT血管造影成像方案

目的优化双下肢动脉能谱CT血管造影(CTA)成像方案。方法回顾性分析30例疑诊双下肢动脉硬化性闭塞症(ASO)患者双下肢动脉能谱CTA资料,经重建获得40~80 keV(间隔5 keV)单能量(共9种)及100 kVp混合能量图像,对比双下肢动脉在不同图像中的CT值、噪声(SD)值、信噪比(SNR)及对比度噪声比(CNR);针对50、60 keV单能量和100 kVp混合能量图像质量及血管节段的可诊断性进行主观评估,观察40、45、50、60 keV单能量和100 kVp混合能量图像的自动去骨能力。结果40~80 keV范围内,随keV升高,各动脉在图像中的CT值、SD值、SNR及CNR均逐渐降低。相比100 kVp,腘动脉(PA)及其近端动脉的CT值、CNR及SNR均在40~55 keV图像中升高(P均<0.05);50~55 keV图像中SD值升高(P均<0.05),而60 keV图像中差异无统计学意义(P>0.05)。50及60 keV图像质量主观评分及可诊断动脉节段数与100 kVp差异均无统计学意义(P均>0.05)。PA以远节段的SNR及CNR在各单能量图像及100 kVp图像中差异均无统计学意义,其CT值在40~45 keV图像中、SD在40 keV图像中均高于100 kVp(P均<0.05),但SD在45 keV与100 kVp图像中差异无统计学意义(P>0.05);50 keV图像中,PA以远节段图像质量主观评分及可诊断节段数均高于60 keV及100 kVp(P均<0.05)。40 keV图像对9例(9/30,30.00%)、45 keV图像对6例(6/30,20.00%)不能自动去骨,50及60 keV、100 kVp对30例(30/30,100%)均可自动去骨。结论行双下肢动脉能谱CTA时,对PA及其近端节段以60 keV单能量成像较佳,对其以远或双下肢全程则以50 keV单能量成像较佳。

经CT扫描探讨正常喉的活动度的研究

目的通过对喉部活动度进行测量,进一步精确勾画喉外扩靶区,以实现肿瘤精确放疗提高放疗效果。方法选取51例肿瘤患者为研究对象,通过CT测量喉部在四个方向最大活动度,通过spss23.0对实验所得数据进行统计分析。结果51位研究对象平均前联合向上最大移动范围为(13.04±6.72)mm,前联合向下最大移动范围为(1.53±2.41)mm,前联合向左最大移动范围为(1.44±1.74)mm,前联合向右最大移动范围为(1.35±2.27)mm,前联合向前最大移动范围为(3.81±2.74)mm,前联合向后最大移动范围为(0.75±1.59)mm,左侧甲状软骨板最大外移为(0.70±1.21)mm,左侧甲状软骨板最大内移为(1.86±2.85)mm,右侧甲状软骨板最大外移为(0.70±1.35)mm,右侧甲状软骨板最大内移为(1.42±1.71)mm,杓前角最大间距为(14.15±3.51)mm。以第一次测量为准确测量值,第二次、第三次测量值与第一次测量值差值绝对值为误差值,比较两次测量误差值。两次测量误差间差异无统计学意义(P>0.05)。≤60岁研究对象与>60岁研究对象的喉部活动度无显著性差异(P>0.05)。男性杓前角最大间距为(15.32±4.72)mm,显著高于女性的(12.14±1.61)mm,差异具有统计学意义(P<0.05)。转移的研究对象左侧甲状软骨板最大内移为(2.36±2.11)mm,显著高于未转移的(1.19±1.73)mm,差异具体统计学意义(P<0.05)。性别与前联合向上最大移动范围、杓前角最大间距呈现显著负相关(P<0.05),与左侧甲状软骨板最大外移呈显著正相关(P<0.05);年龄与前联合向上最大移动范围呈显著正相关(P<0.05),与前联合向下最大移动范围、左侧甲状软骨板最大外移呈显著负相关(P<0.05)。皮尔逊相关性分析发现甲状软骨板前联合向左移动度与左侧甲状软骨板最大外移具有显著正相关性(r=0.301,P=0.032);甲状软骨板前联合向右移动度与右侧甲状软骨板最大外移具有显著正相关性(r=0.072,P=0.000)。结论自然吞咽会引起喉部运动,这种运动的具体范围在肿瘤放射治疗中需被注意。

基于CT技术的黄原胶加固土干湿循环条件下力学性能和微观结构劣化机制研究

干湿循环对岩土体的工程特性具有重要影响。采用CT扫描技术和力学测试,对加入不同含量黄原胶(0%,0.5%,1.5%)加固的黏土在经历不同次数(0,1,4,8,12次)干湿循环作用下的力学性能和微观结构劣化机制进行了研究,得到结论:(1)黄原胶能够有效提高土体的抗压强度和耐干湿循环效果。随着黄原胶含量的增加,干湿循环作用后的强度损失逐渐减小,当循环次数从0次增加到4次时,对于加入黄原胶含量分别为0%,0.5%,1.5%的试样,抗压强度分别损失了42.75%,17.2%,14.04%。(2)加固土的抗压强度与干湿循环次数之间保持指数下降的关系,当循环次数达到4次后,随着循环次数的进一步增加,抗压强度和弹性模量均在较小的变化范围内波动。(3)随着干湿循环次数的增加,黄原胶加固土的孔隙率表现出先增加后减小的趋势,连通孔隙不断扩展,而孤立孔隙表现出先增加后减小的趋势。(4)随着试样的干燥,黄原胶在土颗粒间形成网状基质,提高土体的强度和耐干湿循环能力。

CTA/CTP评估在缺血性脑血管病介入治疗中的应用

目的探讨CT血管成像(CTA)/CT灌注成像(CTP)在缺血性脑血管病介入治疗中的应用价值。方法选取2021年1月至2023年9月我院收治的200例缺血性脑血管病患者,均在入院后接受CTA及CTP检查,分析其影像资料,探究CTA及CTP缺血性脑血管病介入治疗中的应用价值。结果脑血容量(CBV)比较:缺血半暗带>健侧>梗死区(P<0.05);脑血流量(CBF)比较:健侧>缺血半暗带>梗死区(P<0.05);平均通过时间(MTT)、目标组织中浓度达峰时间(TTP)、目标组织中所有残余功能全部达峰时间(Tmax)比较:健侧<缺血半暗带<梗死区(P<0.05)。CTA检出左侧、右侧大脑中动脉(MCA)闭塞或狭窄分别59例(29.50%)、91例(45.50%),左侧、右侧颈内动脉(ICA)闭塞分别16例(8.00%)、12例(6.00%),双侧ICA狭窄为6例(3.00%);代偿分支血管显影基本满意129例(64.50%),显影不足71例(35.50),其余16例(8.00%)患者CTA影像资料显示无异常,敏感度为92.00%。预后不良组患侧CBV、CBF小于预后良好组,MTT、TTP、Tmax长于预后良好组,代偿血管建立比例低于预后良好组(P<0.05)。采用受试者工作特征曲线分析显示,CBV、CBF、MTT、TTP、Tmax对介入治疗预后均有一定的预测效能(P<0.05),其曲线下面积分别为0.839、0.815、0.673、0.713、0.710,其中CBV预测效能最高,敏感性为83.20%,特异性为73.33%。结论CTA/CTP可反映大脑、颈内动脉狭窄或闭塞、代偿分支建立情况,也可反映血流灌注情况,在介入治疗合理时机的判断方面可提供准确依据,提高患者预后。