Value Of Dual-energy CT Research Articles

Quantitative evaluation of disc degeneration using dual-energy CT: advantages of R-VH, D-VH values and the IVNCa + CT model.

To evaluate the correlation between dual-energy CT (DECT) virtual calcium free (VNCA), CT attenuation, the ratio and difference of VNCA to CT attenuation, and Pfirrmann grading of lumbar disc degeneration. A retrospective analysis on 135 intervertebral discs from 30 patients who underwent DECT and MR. Discs was graded using the Pfirrmann system. ROIs on the sagittal plane assessed HU value, VNCA value, Rho value, Z value, R-VH value, and D-VH value. Correlation, grade differences, and multivariate regression models were assessed. Diagnostic performance and cut-off values were determined using AUC. VNCA (r = 0.589, P < 0.001), R-VH (r = 0.622, P < 0.001), and D-VH (r = 0.613, P < 0.001) moderately correlated with Pfirrmann grading. HU (r = 0.388, P < 0.001), Rho (r = 0.142, P = 0.102), and Z (r = -0.125, P = 0.153) showed a weak correlation. R-VH, D-VH, and VNCA had significantly higher correlation than HU. Statistically significant differences were observed in P values of VNCA, HU, R-VH, and D-VH in relative groups (P < 0.05), but not in Rho and Z values (P > 0.05). R-VH and D-VH had significant differences between Pfirrmann grades 1 and 2, and grades 2 and 3 (early stage) (P < 0.05). AUC readings of R-VH and D-VH (≥2, ≥3, ≥4) were higher. The multivariate model IVNCa + CT had the highest AUC. The new quantitative indices R-VH value and D-VH value of DECT have advantages over VNCA value and HU value in evaluating early-stage disc degeneration (≥2 grades, ≥3 grades). The multivariate model IVNCa + CT has the best AUC values for evaluating disc degeneration at all stages.

OC-0466 Clinical value of dual energy CT based delineation in the treatment planning for prostate patients

OC-0466 Clinical value of dual energy CT based delineation in the treatment planning for prostate patients

Bowel Peristalsis Artifact on Dual-Energy CT: In Vitro Study on the Influence of Different Dual-Energy CT Platforms and Enteric Contrast Agents.

BACKGROUND. The value of dual-energy CT (DECT) for bowel wall assessment is increasingly recognized. Although technical improvements reduce peristalsis artifact in conventional CT, the effects of peristalsis on DECT image reconstructions remain poorly studied. OBJECTIVE. The purpose of this study was to evaluate the influence of different DECT scanners and enteric contrast agents on the severity of bowel peristalsis artifact in vitro. METHODS. To simulate bowel peristalsis, a 3-cm-diameter corrugated hollow tube representing the bowel was oscillated constantly in the z-axis within a larger water-filled cylinder. The bowel was serially filled with air, water, and iodinated or experimental dark contrast material and scanned on four different DECT platforms (spectral detector, rapid peak kilovoltage switching, split filter, and dual source) to reconstruct 120-kVp-like and iodine images. Two readers rated each image reconstruction for artifact severity from 0 (none) to 3 (severe) and recorded the degree to which iodine images depicted bowel wall hyperattenuation on 120-kVp-like images as artifactual. Artifact severity scores were compared by ANOVA with Bonferroni correction. RESULTS. Interrater agreement on artifact scores was excellent (intraclass correlation coefficient, 0.82 [95% CI, 0.79-0.84]). For 120-kVp-like images, mean peristalsis artifact scores were lower (all p < .001) for split-filter (1.47) and dual-source (1.86) scanners than for spectral-detector (2.58) and rapid-kilovoltage-switching (2.74) scanners. Compared with those on 120-kVp images, peristalsis artifacts on iodine images were less severe for spectral-detector (score, 1.03; p < .001) and rapid-kilovoltage-switching (2.09; p < .001) systems but more severe for dual-source (2.77; p < .001) and split-filter (2.62; p < .001) systems. Peristalsis artifact was rated less severe with experimental dark bowel contrast medium (score, 1.79) than with other bowel contrast agents (all p < .001). Iodine images helped identify bowel wall hyperattenuation as artifactual in 94.7% of reviewed cases for spectral-detector and 40.7% of cases for rapid-kilovoltage-switching scanners. CONCLUSION. For spectral-detector and rapid-kilovoltage-switching DECT, iodine images minimize peristalsis artifact, but for dual-source and split-filter DECT, mixed 120-kVp-like images are preferred. Compared with iodinated contrast material and water, experimental dark bowel contrast material reduces peristalsis artifact. CLINICAL IMPACT. Knowledge of the preferred images for reducing peristalsis artifact can lessen the effect of peristalsis on clinical DECT interpretation. Dark enteric contrast agents, when they become clinically available, may further reduce the effects of peristalsis.

Pulmonary Artery Sarcoma: Value of Dual-Energy CT (DECT)-Based Iodine Quantification on Multimodality Workup

Pulmonary Artery Sarcoma: Value of Dual-Energy CT (DECT)-Based Iodine Quantification on Multimodality Workup

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.

Detection of monosodium urate crystals with dual-energy CT in gout patients

Objective To evaluate the application of the dual-energy CT (DECT) in detection of monosodium urate (MSU) crystals in gout patients. Methods The imaging and clinical data of 101 patients with suspected gout were retrospectively analyzed, including 64 cases of clinically diagnosed gout (gout group) and 37 non-gout cases (non-gout group). The DECT examination was performed for 85 joints in gout group and 42 joints in non-joint group. The value of DECT in detection of MSU crystals was evaluated with receiver operating characteristic (ROC) curve. Results There were significant differences in gender (χ2=5.32, P=0.03) and blood uric acid levels (t=1.95, P=0.04) between gout and non-gout groups. The detection rate of MSU in gout group was significantly higher than that of non-gout group (χ2=30.52, P<0.001). The area under the ROC curve (AUC) of DECT in detection of was 0.74±0.05 (Mean±SE), 95%CI: 0.64-0.85. The sensitivity, specificity, positive predictive value and negative predictive value of the DECT in detection of gouty stone was 0.844, 0.703, 83.1% and 72.2%, respectively. Conclusion The dual-energy CT has high sensitivity, specificity and reliability for the detection and diagnosis of monosodium urate crystals in joints of gout patients. Key words: Radiography, dual-energy scanned projection; Gout; Arthritis, gouty; Crystallization, uric acid

Diagnostic value of dual energy CT for lymph node metastasis in patients with non-small cell lung cancer

To assess the diagnostic value of dual energy CT for lymph node metastasis in patients with non-small cell lung cancer (NSCLC). Forty NSCLC patients, including 15 cases of squamous cell carcinoma and 25 cases of adenocarcinoma, underwent dual energy CT examination in pre-contrast and venous phase contrast scans, then the CT attenuation value of the lung cancer lesions and 85 mediastinal enlarged lymph nodes (the short diameter ≥ 5 mm, 53 metastatic and 32 non-metastatic) were measured at different energy levels (40-190 keV, spacing 10 keV) in venous phase contrast. CT spectral curves of the lung cancer lesions, hilus pulmonis and mediastinal enlarged lymph nodes were produced automatically, through comparing their CT spectral curves slope to judge whether or not the lymph nodes were metastatic. Receiver operating characteristic (ROC) curve was used to evaluate the efficiency of CT spectral curve in diagnosis of lymph node metastasis. The CT spectral curves slopes of the lung cancer, metastatic lymph nodes and non-metastatic lymph nodes were 1.10±0.11, 1.08±0.07 and 1.54±0.17, respectively. There was no significant difference in curve slope between metastatic lymph nodes and lung cancer (t=-1.32,P>0.05); while there was significant difference between non-metastatic lymph nodes and lung cancer (t=-2.58,P<0.05). The CT spectral curve slope ratios of metastatic and non-metastatic lymph nodes to lung cancer were 0.98±0.05 and 1.40±0.12, respectively (t=-2.86,P<0.05). ROC curve showed that taking CT spectral curve slope ratio of 1.15 as cut-off value for the diagnosis of metastatic lymph nodes, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 81.1%, 87.5%, 91.5%, 73.7% and 83.5%, respectively. Dual energy CT is of value in improving the diagnostic accuracy of lymph node metastasis in NSCLC patients before treatment.

Dual Energy CT- Surrogate Quantitative Marker of Response to Targetted treatment in HCC

Background and Aim: Dual energy CT (DECT)– novel CT imaging technique at two different energies, can be used to discriminate between different materials (e.g., fat, calcium, iodine, and water), which are not allowed by conventional CT. The images reconstructed from these differential data, including iodine concentration maps, may provide diagnostic information beyond that obtainable with conventional CT Aim: To evaluate the supplementary value of dual energy CT to assess response in cirrhotic patients with HCC following targeted therapy. Methods: 20 patients with targeted therapies for dual energy CT (TACE/TARE/RFA) were evaluated. Iodine uptake(IU), derived from the iodine-based material-decomposition image and the iodine concentration ratio on the dual energy CT acquired during early portal venous phase was calculated by drawing regions of interest within the treated lesion, at the edge and within the surrounding liver parenchyma. Quantification of IU (absolute value for total IU (mg) and volume-normalized IU (mg/ml)) was based on semi-automatic tumor volume segmentation compared to the background liver. The decrease compared with baseline was calculated. Results: The mean normalized IU per patient within the treated lesion compared to the cirrhotic liver parenchyma -31%. Total IU per patient, combining both normalized IU and volume, showed the most pronounced decrease. Conclusion: DECT enables objective, easy and fast parameterization of tumor size and contrast medium uptake. DECT provides a quantitative method with which to analyze the treated lesions in the cirrhotic liver. The authors have none to declare.

The diagnostic value of dual-energy dual-phase CT in small clear cell renal cell carcinoma

Objective To detect the best phase and best tube voltage for the diagnosis of small (diameter≤3 cm) clear cell renal cell carcinoma with dual-energy dual-phase CT. Methods Image manifestations of 27 patients with small (diameter≤3 cm) cc RCCs confirmed by pathology were retrospectively analyzed.All subjects underwent dual-energy biphase (early corticomedullary and delayed phase) scan preoperatively.Two senior radiologists analyzed the images in consensus.The definition of images in different phases and with different tube voltage was classified into 4 levels and was compared by Wilcoxon and Friedman test.The attenuation of the lesions and the adjacent renal parenchyma,the SD value of the anterior abdomen fat were measured.The contrast noise ratio (CNR),lesion kidney ratio (LKR) and the early corticomedullary phase and delayed phase value were calculated.They were all compared with one-way ANOVA. Results The score of definition of lesions in early corticomedullary phase at 80 k V,140 k V and average-weighted 120 k V were 3.30±0.87,2.81±0.92 and 3.11±0.85,respectively,which in delayed phase were 3.70±0.54,3.30±0.82 and 3.52±0.64,respectively.Definition of lesions was better in delayed phase than that in early corticomedullary phase (Z=-2.296,-2.446 and-2.392,respectively;P<0.05).Either in early corticomedullary phase or in delayed phase,CT value,noise value and CNR were the highest on 80 k V images,which were (302±80) HU,(16.2±2.2) and (4.1±3.4) in corticomedullary phase and (152±31) HU,(16.4±2.7) HU,and (4.7±1.7) in delayed phase.The change of lesion attenuation between early corticomedullary phase and delayed phase on 80 k V,140 k V and average-weighted 120 k V images were (150±76),(72±33) and (96±46) HU,respectively.There was significant difference among the three groups (F=4.541,P<0.01). Conclusions Delayed phase scan is in favor of small clear cell renal cell carcinoma display.80 k V images are the best for detecting and qualitation of small clear cell renal cell carcinoma when compared with 140 k V and the average-weighted 120 k V images. Key words: Renal neoplasms; Tomography,X-ray computed

The value of dual-energy CT in diagnosing pulmonary embolism in children

Objective To evaluate the value of dual energy CT with Lung Vessels application in diagnosing pulmonary embolism (PE) of children. Methods Forty-seven patients with nephrotic syndrome and aged≤18 years old (32 male,15 female,mean age 15 years) underwent dual-energy CT pulmonary angiography (CTPA).Two radiologists recorded the presence or absence of emboli and counted the clots on a per-patient and per-lobe basis with Lung Vessels,respectively.With conventional CTPA as reference standard,sensitivity,specificity,positive predictive value (PPV),negative predictive value (NPV) of Lung Vessels application to detect PE were computed for two readers.Inter-reader agreement was also calculated. Results Conventional CTPA detected 51 clots in 35 lung lobes in 13 patients,giving PE incidence was 27.6% (13/47) for this cohort.On a per-patient basis,readers 1 and 2 detected 25 and 21 patients with PE with Lung Vessels,corresponding to sensitivities,specificities,PPVs,and NPVs of 100.0% (13/13),58.6% (17/29),43.3% (13/30),100.0% (17/17) and 100.0% (13/13),76.5% (21/29),50.0% (13/26),100.0% (21/21), Key words: Pulmonary embolism; Children; Nephrotic syndrome; Tomography,X-ray computed

Dual energy CT for the assessment of lung perfusion—Correlation to scintigraphy

Purpose of this study was to determine the diagnostic value of dual energy CT in the assessment of pulmonary perfusion with reference to pulmonary perfusion scintigraphy. Thirteen patients received both dual energy CT (DECT) angiography (Somatom Definition, Siemens) and ventilation/perfusion scintigraphy. Median time between scans was 3 days (range, 0–90). DECT perfusion maps were generated based on the spectral properties of iodine. Two blinded observes assessed DECT angiograms, perfusion maps and scintigrams for presence and location of perfusion defects. The results were compared by patient and by segment, and diagnostic accuracy of DECT perfusion imaging was calculated regarding scintigraphy as standard of reference. Diagnostic accuracy per patient showed 75% sensitivity, 80% specificity and a negative predictive value of 66%. Sensitivity per segment amounted to 83% with 99% specificity, with 93% negative predictive value. Peripheral parts of the lungs were not completely covered by the 80 kVp detector in 85% of patients. CTA identified corresponding emboli in 66% of patients with concordant perfusion defects in DECT and scintigraphy. Dual energy CT perfusion imaging is able to display pulmonary perfusion defects with good agreement to scintigraphic findings. DECT can provide a pulmonary CT angiogram, high-resolution morphology of the lung parenchyma and perfusion information in one single exam.

Quantitative diagnosis of fatty liver with dual-energy CT: An experimental study in rabbits

To explore the correlation between fatty content of fatty liver and the difference of CT attenuation value in dual-energy CT, and to evaluate the value of dual-energy CT in the quantitative diagnosis of fatty liver in rabbits. Dual-energy CT at 120 kVp and 90 kVp was performed in 16 rabbits of experimental groups that were induced to various degrees of fatty liver by feeding carbon tetrachloride (CCl4). Four healthy rabbits in the control group underwent dual-energy CT at the same time. The CT attenuation values of liver tissues at 120 kVp (H120), 90 kVp (H90) and the difference (Delta H) between them were obtained. The specimens of liver tissues were examined with freeze section (9 microm) and an oil red O stain histologically. The ratio of fatty content in liver to the liver volume (VP value) was measured using the image analyzer system. The change of CT attenuation values between 120 kVp and 90 kVp was not obvious (Delta H between -0.4 HU and 1.4 HU) in the control group. The density of the liver in the experimental groups decreased differently, and the change in CT attenuation values between high and low energy levels were very clear. H120 values were between 51.0 HU and 91.7 HU and H90 values were between 37.0 HU and 89.2 HU. Delta H values were between 2.5 HU and 14.0 HU. Significant negative linear correlation (r = -0.92, -0.93, t = 8.51, 9.76, p < 0.001, 0.001, respectively) were found between VP values and H120 and H90, respectively, while significant positive linear correlation (r = 0.95, t = 11.89, p < 0.001) was found between VP values and Delta H. The amount and degree of fat in the fatty liver can be assessed exactly by dual-energy CT. It will be a potential new effective method for quantitative diagnosis of fatty livers.

Value of dual-energy CT in differentiating focal fatty infiltration of the liver from low-density masses.

Focal (irregular, partial) fatty infiltration of the liver may simulate neoplastic or other hypodense masses on CT. On the basis of previous observations of the phenomenon that differences in X-ray attenuation diminish with increasing energy of X-rays used, we performed a preliminary study to determine if dual-energy CT could be used to discriminate between fatty infiltration and hypodense liver masses. Dual-energy CT at 140 and 80 kVp was performed in 14 patients undergoing liver biopsy and in seven control subjects with presumedly normal liver. Attenuation measurements were taken, and the changes in attenuation between 140 and 80 kVp were calculated. The mean changes in attenuation were 3.5 H for normal liver (n = 7), 2.5 H for hypodense liver masses (n = 6), 13 H for fatty liver (n = 5), 0.3 H for fatty liver combined with hemochromatosis or hemosiderosis (n = 3), and 2 H for the spleen (n = 18). The change in attenuation increased as the fat content in the liver increased. Analysis of variance showed a statistically significant difference (p less than .001) between fatty liver and the other groups. A difference greater than 10 H was unique to fatty infiltration. These results suggest that dual-energy CT may help to differentiate focal fatty infiltration of the liver from low-density neoplastic or other lesions, but only if the iron content of the liver is not increased.