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Non-contrast estimation of diffuse myocardial fibrosis with dual energy CT: A phantom study. Kumar Vidhya,McElhanon Kevin E,Min James K,He Xin,Xu Zhaobin,Beck Eric X,Simonetti Orlando P,Weisleder Noah,Raman Subha V Journal of cardiovascular computed tomography BACKGROUND:Estimation of diffuse myocardial fibrosis, substrate for adverse events such as heart failure and arrhythmias in patients with various cardiac disorders, is presently done by histopathology or cardiac magnetic resonance. We sought to develop a non-contrast method to estimate the amount of diffuse myocardial fibrosis leveraging dual energy computed tomography (DECT) in phantoms and a suitable small animal model. METHODS AND RESULTS:Phantoms consisted of homogenized bovine myocardium with varying amounts of Type 1 collagen. Fifteen mice underwent sham surgery, no procedure, or transverse aortic constriction (TAC) for 5 or 8 weeks to produce moderate or severe fibrosis, respectively. Phantoms and ex vivo mouse hearts were imaged on a single source, DECT scanner equipped with kVp switching. Monochromatic images were reconstructed at 40-140 keV. Linear discriminant analysis (LDA) was performed on mean myocardial CT numbers derived from single energy (70 keV) images as well as images reconstructed across multiple energies. Classification of myocardial fibrosis severity as low, moderate or severe was more often correct using the multi-energy CT/LDA approach vs. single energy CT/LDA in both phantoms (80.0% vs. 70.0%) and mice (93.3% vs. 33.3%). CONCLUSIONS:DECT myocardial imaging with multi-energy analysis better classifies myocardial fibrosis severity compared to a single energy-based approach. Non-contrast DECT can accurately and non-invasively estimate the extent of diffuse myocardial fibrosis in phantom and animal models. These data support further evaluation of this approach for in vivo myocardial fibrosis estimation. 10.1016/j.jcct.2017.12.002
Radiological differences between chronic thromboembolic pulmonary disease (CTEPD) and chronic thromboembolic pulmonary hypertension (CTEPH). Capone Carmine,Valentini Adele,Spinillo Silvia Lina,Klersy Catherine,Celentano Anna,Pin Maurizio,Monterosso Cristian,Dore Roberto,Bassi Emilio Maria,Zacchino Michela,Rodolico Giuseppe,Corsico Angelo Guido,Preda Lorenzo,Ghio Stefano,D'Armini Andrea Maria European radiology OBJECTIVES:The aim of this study was to describe the radiological features of chronic thromboembolic pulmonary disease (CTEPD), not yet systematically described in the literature. Furthermore, we compared vascular scores between CTEPD and chronic thromboembolic pulmonary hypertension (CTEPH) patients, trying to explain why pulmonary hypertension does not develop at rest in CTEPD patients. METHODS:Eighty-five patients (40 CTEPD, 45 CTEPH) referred to our centre for pulmonary endarterectomy underwent dual-energy computed tomography pulmonary angiography (DE-CTPA) with iodine perfusion maps; other 6 CTEPD patients underwent single-source CTPA. CT scans were reviewed independently by an experienced cardiothoracic radiologist and a radiology resident to evaluate scores of vascular obstruction, hypoperfusion and mosaic attenuation, signs of pulmonary hypertension and other CT features typical of CTEPH. RESULTS:Vascular obstruction burden was similar in the two groups (p = 0.073), but CTEPD patients have a smaller extension of perfusion defects in the iodine map (p = 0.009) and a smaller number of these patients had mosaic attenuation (p < 0.001) than CTEPH patients, suggesting the absence of microvascular disease. Furthermore, as expected, the two groups were significantly different considering the indirect signs of pulmonary hypertension (p < 0.001). CONCLUSIONS:CTEPD and CTEPH patients have significantly different radiological characteristics, in terms of signs of pulmonary hypertension, mosaic attenuation and iodine map perfusion extension. Importantly, our results suggest that the absence of peripheral microvascular disease, even in presence of an important thrombotic burden, might be the reason for the absence of pulmonary hypertension in CTEPD. KEY POINTS:• CTEPD and CTEPH patients have significantly different radiological characteristics. • The absence of peripheral microvascular disease might be the reason for the absence of pulmonary hypertension in CTEPD. 10.1007/s00330-020-07556-4
Imaging of ventilation with dual-energy CT during breath hold after single vital-capacity inspiration of stable xenon. Honda Norinari,Osada Hisato,Watanabe Wataru,Nakayama Mitsuo,Nishimura Keiichiro,Krauss Bernhard,Otani Katharina Radiology PURPOSE:To assess single-breath-hold technique for ventilation mapping by using dual-energy computed tomography (CT) in phantom experiments and volunteers. MATERIALS AND METHODS:Institutional review board approved this study, and written informed consent was obtained from all volunteers. A rubber bag filled with a mixture of xenon (0%-35.4%) and oxygen was scanned with dual-source dual-energy CT (80 kV and 140 kV with tin [Sn] filter [Sn/140 kV] and 100 kV and Sn/140 kV). A cylinder containing six tubes of identical sizes with different apertures was ventilated once with a mixture of 35% xenon and 65% oxygen and was scanned in dual-energy mode (80 kV and Sn/140 kV). Xenon-enhanced images were derived by using three-material decomposition technique. Four volunteers were scanned twice in dual-energy mode (80 kV and Sn/140 kV) during breath hold after a single vital-capacity inspiration of air (nonenhanced) and of 35% xenon. Xenon-enhanced images were obtained by using two methods: three-material decomposition and subtraction of nonenhanced from xenon-enhanced images. Regression analysis with t and F tests was applied to the data of the rubber bag scans, with the significance level set at .05. RESULTS:Mean pixel values of gas in the bag were linearly related to xenon concentration for all x-ray tube voltages (r(2) = 1.00, P < .00001). Pixel values of the xenon-enhanced images of the tubes were related to their aperture size. Nearly homogeneous (coefficient of variation: 0.22, 0.23, and 0.34) pixel values were found in the lungs of healthy volunteers, with higher pixel values in the trachea and lower pixel values in the bullae. Xenon-enhanced images calculated by using three-material decomposition had better image quality on visual comparison than those calculated by using subtraction. CONCLUSION:Xenon-enhanced dual-energy CT with the single-breath-hold technique could depict ventilation in phantoms and in four volunteers. 10.1148/radiol.11110569
Krypton ventilation imaging using dual-energy CT in chronic obstructive pulmonary disease patients: initial experience. Hachulla Anne-Lise,Pontana François,Wemeau-Stervinou Lidwine,Khung Suonita,Faivre Jean-Baptiste,Wallaert Benoit,Cazaubon Jean-François,Duhamel Alain,Perez Thierry,Devos Patrick,Remy Jacques,Remy-Jardin Martine Radiology PURPOSE:To evaluate the tolerance and level of enhancement achievable after inhalation of stable krypton. MATERIALS AND METHODS:This study was approved by the institutional review board and the local ethics committee. Written informed consent was obtained from all subjects. The study was planned as a Fleming two-stage design, enabling one to assess the effectiveness of a newer treatment or technique on a small number of patients. At the end of each stage, the results are computed, and the trial can be stopped if the effectiveness is less than a minimum success rate or greater than an expected success rate. After informed consent was obtained, a total of 32 patients (ie, two successive series of 16 patients each) with severe emphysema underwent a dual-source, dual-energy chest computed tomographic (CT) examination after inhalation of a mixture of stable krypton (80%) and oxygen (20%), with reconstruction of diagnostic and ventilation images. For each patient, two regions of interest were selected on a diagnostic image, one in a region of severe emphysema (presumed to be poorly ventilated or not ventilated) and a second one in a region devoid of structural abnormalities (presumed to be normally ventilated), with measurements of attenuation values on the corresponding ventilation image. RESULTS:All examinations were successfully performed, without adverse effects. Differences in attenuation between normal lung and emphysematous areas were found in 28 patients (88%; 95% confidence interval: 71%, 96.5%). The maximal level of attenuation within normal lung was 18.5 HU. Krypton attenuation difference between normal and emphysematous lung was significant, with a median value of 51.8% (P < .001). CONCLUSION:The level of enhancement after inhalation of krypton and its excellent clinical tolerance makes this gas eligible for ventilation CT examinations. 10.1148/radiol.12111211
Radiation dose reduction of chest CT with iterative reconstruction in image space - Part II: assessment of radiologists' preferences using dual source CT. Hwang Hye Jeon,Seo Joon Beom,Lee Jin Seong,Song Jae-Woo,Kim Song Soo,Lee Hyun Joo,Lim Chae Hun Korean journal of radiology OBJECTIVE:To evaluate the impact of radiation dose and reconstruction algorithms on radiologists' preferences, and whether an iterative reconstruction in image space (IRIS) can be used for dose reduction in chest CT. MATERIALS AND METHODS:Standard dose chest CT (SDCT) in 50 patients and low dose chest CT (LDCT) in another 50 patients were performed, using a dual-source CT, with 120 kVp and same reference mAs (50 mAs for SDCT and 25 mAs for LDCT) employed to both tubes by modifying the dual-energy scan mode. Full-dose data were obtained by combining the data from both tubes and half-dose data were separated from one tube. These were reconstructed by using a filtered back projection (FBP) and IRIS: full-dose FBP (F-FBP); full-dose IRIS (F-IRIS); half-dose FBP (H-FBP) and half-dose IRIS (H-IRIS). Ten H-IRIS/F-IRIS, 10 H-FBP/H-IRIS, 40 F-FBP/F-IRIS and 40 F-FBP/H-IRIS pairs of each SDCT and LDCT were randomized. The preference for clinical usage was determined by two radiologists with a 5-point-scale system for the followings: noise, contrast, and sharpness of mediastinum and lung. RESULTS:Radiologists preferred IRIS over FBP images in the same radiation dose for the evaluation of the lungs in both SDCT (p = 0.035) and LDCT (p < 0.001). When comparing between H-IRIS and F-IRIS, decreased radiation resulted in decreased preference. Observers preferred H-IRIS over F-FBP for the lungs in both SDCT and LDCT, even with reduced radiation dose by half in IRIS image (p < 0.05). CONCLUSION:Radiologists' preference may be influenced by both radiation dose and reconstruction algorithm. According to our preliminary results, dose reduction at 50% with IRIS may be feasible for lung parenchymal evaluation. 10.3348/kjr.2012.13.6.720
Reduction of clinical safety margins in proton therapy enabled by the clinical implementation of dual-energy CT for direct stopping-power prediction. Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology PURPOSE:To quantifiy the range uncertainty in proton treatment planning using dual-energy computed tomography (DECT) for a direct stopping-power prediction (DirectSPR) algorithm and its clinical implementation. METHODS AND MATERIALS:To assess the overall uncertainty in stopping-power ratio (SPR) prediction of a DirectSPR implementation calibrated for different patient geometries, the influencing factors were categorized in imaging, modeling as well as others. The respective SPR uncertainty was quantified for lung, soft tissue and bone and translated into range uncertainty for several tumor types. The amount of healthy tissue spared was quantified for 250 patients treated with DirectSPR and the dosimetric impact was evaluated exemplarily for a representative brain-tumor patient. RESULTS:For bone, soft tissue and lung, an SPR uncertainty (1σ) of 1.6%, 1.3% and 1.3% was determined for DirectSPR, respectively. This allowed for a reduction of the clinically applied range uncertainty from currently (3.5% + 2 mm) to (1.7% + 2 mm) for brain-tumor and (2.0% + 2 mm) for prostate-cancer patients. The 150 brain-tumor and 100 prostate-cancer patients treated using DirectSPR benefitted from sparing on average 2.6 mm and 4.4 mm of healthy tissue in beam direction, respectively. In the representative patient case, dose reduction in organs at risk close to the target volume was achieved, with a mean dose reduction of up to 16% in the brainstem. Patient-specific DECT-based treatment planning with reduced safety margins was successfully introduced into clinical routine. CONCLUSIONS:A substantial increase in range prediction accuracy in clinical proton treatment planning was achieved by patient-specific DECT-based SPR prediction. For the first time, a relevant imaging-based reduction of range prediction uncertainty on a 2% level has been achieved. 10.1016/j.radonc.2021.11.002
Dual-energy CT to estimate clinical severity of chronic thromboembolic pulmonary hypertension: Comparison with invasive right heart catheterization. Takagi Hidenobu,Ota Hideki,Sugimura Koichiro,Otani Katharina,Tominaga Junya,Aoki Tatsuo,Tatebe Shunsuke,Miura Masanobu,Yamamoto Saori,Sato Haruka,Yaoita Nobuhiro,Suzuki Hideaki,Shimokawa Hiroaki,Takase Kei European journal of radiology PURPOSE:To evaluate whether the extent of perfusion defects assessed by examining lung perfused blood volume (PBV) images is a stronger estimator of the clinical severity of chronic thromboembolic pulmonary hypertension (CTEPH) compared with other computed tomography (CT) findings and noninvasive parameters. MATERIALS AND METHODS:We analyzed 46 consecutive patients (10 men, 36 women) with CTEPH who underwent both dual-energy CT and right-heart catheter (RHC) examinations. Lung PBV images were acquired using a second-generation dual-source CT scanner. Two radiologists independently scored the extent of perfusion defects in each lung segment employing the following criteria: 0, no defect, 1, defect in <50% of a segment, 2, defect in ≥50% of a segment. Each lung PBV score was defined as the sum of the scores of 18 segments. In addition, all of the following were recorded: 6-min walk distance (6MWD), brain natriuretic peptide (BNP) level, and RHC hemodynamic parameters including pulmonary artery pressure (PAP), right ventricular pressure (RVP), cardiac output (CO), the cardiac index (CI), and pulmonary vascular resistance (PVR). Bootstrapped weighted kappa values with 95% confidence intervals (CIs) were calculated to evaluate the level of interobserver agreement. Correlations between lung PBV scores and other parameters were evaluated by calculating Spearman's rho correlation coefficients. Multivariable linear regression analyses (using a stepwise method) were employed to identify useful estimators of mean PAP and PVR among CT, BNP, and 6MWD parameters. A p value<0.05 was considered to reflect statistical significance. RESULTS:Interobserver agreement in terms of the scoring of perfusion defects was excellent (κ=0.88, 95% CIs: 0.85, 0.91). The lung PBV score was significantly correlated with the PAP (mean, rho=0.48; systolic, rho=0.47; diastolic, rho=0.39), PVR (rho=0.47), and RVP (rho=0.48) (all p values<0.01). Multivariable linear regression analyses showed that only the lung PBV score was significantly associated with both the mean PAP (coefficient, 0.84, p<0.01) and the PVR (coefficient, 28.83, p<0.01). CONCLUSION:The lung PBV score is a useful and noninvasive estimator of clinical CTEPH severity, especially in comparison with the mean PAP and PVR, which currently serve as the gold standards for the management of CTEPH . 10.1016/j.ejrad.2016.06.010
Automatic pulmonary vessel segmentation on noncontrast chest CT: deep learning algorithm developed using spatiotemporally matched virtual noncontrast images and low-keV contrast-enhanced vessel maps. Nam Ju Gang,Witanto Joseph Nathanael,Park Sang Joon,Yoo Seung Jin,Goo Jin Mo,Yoon Soon Ho European radiology OBJECTIVES:To develop a deep learning-based pulmonary vessel segmentation algorithm (DLVS) from noncontrast chest CT and to investigate its clinical implications in assessing vascular remodeling of chronic obstructive lung disease (COPD) patients. METHODS:For development, 104 pulmonary CT angiography scans (49,054 slices) using a dual-source CT were collected, and spatiotemporally matched virtual noncontrast and 50-keV images were generated. Vessel maps were extracted from the 50-keV images. The 3-dimensional U-Net-based DLVS was trained to segment pulmonary vessels (with a vessel map as the output) from virtual noncontrast images (as the input). For external validation, vendor-independent noncontrast CT images (n = 14) and the VESSEL 12 challenge open dataset (n = 3) were used. For each case, 200 points were selected including 20 intra-lesional points, and the probability value for each point was extracted. For clinical validation, we included 281 COPD patients with low-dose noncontrast CTs. The DLVS-calculated volume of vessels with a cross-sectional area < 5 mm (PVV5) and the PVV5 divided by total vessel volume (%PVV5) were measured. RESULTS:DLVS correctly segmented 99.1% of the intravascular points (1,387/1,400) and 93.1% of the extravascular points (1,309/1,400). The areas-under-the receiver-operating characteristic curve (AUROCs) were 0.977 and 0.969 for the two external validation datasets. For the COPD patients, both PPV5 and %PPV5 successfully differentiated severe patients whose FEV1 < 50 (AUROCs; 0.715 and 0.804) and were significantly correlated with the emphysema index (Ps < .05). CONCLUSIONS:DLVS successfully segmented pulmonary vessels on noncontrast chest CT by utilizing spatiotemporally matched 50-keV images from a dual-source CT scanner and showed promising clinical applicability in COPD. KEY POINTS:• We developed a deep learning pulmonary vessel segmentation algorithm using virtual noncontrast images and 50-keV enhanced images produced by a dual-source CT scanner. • Our algorithm successfully segmented vessels on diseased lungs. • Our algorithm showed promising results in assessing the loss of small vessel density in COPD patients. 10.1007/s00330-021-08036-z
Regional Distribution of Pulmonary Blood Volume with Dual-Energy Computed Tomography: Results in 42 Subjects. Felloni Paul,Duhamel Alain,Faivre Jean-Baptiste,Giordano Jessica,Khung Suonita,Deken Valérie,Remy Jacques,Remy-Jardin Martine Academic radiology RATIONALE AND OBJECTIVES:The noninvasive approach of lung perfusion generated from dual-energy computed tomography acquisitions has entered clinical practice. The purpose of this study was to analyze the regional distribution of iodine within distal portions of the pulmonary arterial bed on dual-source, dual-energy computed tomography examinations in a cohort of subjects without cardiopulmonary pathologies. MATERIALS AND METHODS:The study population included 42 patients without cardiorespiratory disease, enabling quantitative and qualitative analysis of pulmonary blood volume after administration of a 40% contrast agent. Qualitative analysis was based on visual assessment. Quantitative analysis was obtained after semiautomatic division of each lung into 18 areas. RESULTS:The iodine concentration did not significantly differ between the right (R) and left (L) lungs (P = .49), with a mean attenuation of 41.35 Hounsfield units (HU) and 41.14 HU, respectively. Three regional gradients of attenuation were observed between: (a) lung bases and apices (P < .001), linked to the conditions of examination (mean Δ: 6.23 in the R lung; 5.96 in the L lung); (b) posterior and anterior parts of the lung (P < .001) due to gravity (mean Δ: 11.92 in the R lung ; 15.93 in the L lung); and (c) medullary and cortical lung zones (P < .001) (mean Δ: 9.35 in the R lung ; 8.37 in the L lung). The intensity of dependent-nondependent (r = 0.42; P < .001) and corticomedullary (r = 0.58; P < .0001) gradients was correlated to the overall iodine concentration. CONCLUSION:Distribution of pulmonary blood volume is influenced by physiological gradients and scanning conditions. 10.1016/j.acra.2017.05.003
Dual-energy CT angiography of the lungs: comparison of test bolus and bolus tracking techniques for the determination of scan delay. Henzler Thomas,Meyer Mathias,Reichert Miriam,Krissak Radko,Nance John W,Haneder Stefan,Schoenberg Stefan O,Fink Christian European journal of radiology OBJECTIVE:To prospectively compare test bolus and bolus tracking for the determination of scan delay of pulmonary dual-energy CT angiography in patients with suspected pulmonary embolism. MATERIALS AND METHODS:60 consecutive patients referred for CTA for exclusion of PE were randomized either into a test bolus group or into a bolus tracking group. All exams were performed on a 64-channel dual source CT scanner. A standard single-acquisition dual-energy CTA was performed after injection of 100ml Iomeprol 400 followed by a saline chaser of 4 ml/s. The scan delay was determined using either test bolus (n=30) or bolus tracking (n=30). Test bolus was performed using an additional 20 ml Iomeprol 400 injected with a rate of 4 ml/s during acquisition of a series of dynamic low-dose monitoring scans followed by injection of a saline bolus of 20 ml using the same flow rate. For DECT angiography of the lungs 100ml Iomeprol 400 was injected with an injection rate of 4 ml/s followed by a saline chaser of 20 ml using the same flow rate. Attenuation profiles of different vascular segments (pulmonary arteries, pulmonary parenchyma, aorta, all 4 heart chambers) were measured to evaluate the timing techniques. Overall image quality of dual-energy "perfusion" maps and virtual 120 kV CTA images was evaluated by two radiologists regarding the present of artifacts. RESULTS:In all patients an adequate and homogeneous contrast enhancement of more than 400 Hounsfield units (HU) was achieved in the different vascular districts. No statistically significant difference between test bolus and bolus tracking was found regarding vessel attenuation or overall image quality. CONCLUSION:A homogeneous opacification of the different vascular territories and the pulmonary parenchyma as well as a sufficient image quality can be achieved with either bolus tracking or test bolus techniques. 10.1016/j.ejrad.2010.06.023
Prediction of postoperative lung function in patients undergoing lung resection: dual-energy perfusion computed tomography versus perfusion scintigraphy. Chae Eun Jin,Kim Namkug,Seo Joon Beom,Park Joo-Young,Song Jae-Woo,Lee Hyun Joo,Hwang Hye Jeon,Lim Chaehun,Chang Yong Jin,Kim Yong Hee Investigative radiology OBJECTIVES:The purpose of this study was to assess the usefulness of dual-energy perfusion computed tomography (CT) for predicting postoperative lung function in patients undergoing lung resection. METHODS:Fifty-one patients (38 men, 13 women; mean age, 63.8 years) were prospectively enrolled and subsequently underwent dual-energy CT, perfusion scintigraphy, a pulmonary function test before surgery, and a pulmonary function test 6 months after surgery. Computed tomography was performed using dual-source CT with the dual-energy technique. Using weighted average images, each lobe was segmented and using perfusion images, the iodine value was quantitatively measured. Lobar perfusion was calculated by multiplying the volume of the lobe by the iodine value. The ratio of lobar perfusion per whole-lung perfusion was then calculated. The predicted postoperative forced expiratory volume during 1 second (post-FEV1) was calculated by multiplying the preoperative FEV1 by the fractional contribution of perfusion of the remaining lung. The agreement between the predicted post-FEV1 and the actual post-FEV1 was then evaluated. The percentage of error of the predicted post-FEV1 to that of the actual post-FEV1 was then calculated. RESULTS:Using the Bland-Altman method, the limits of agreement between the actual post-FEV1 and the predicted post-FEV1 were -29.3% and 26.9% for scintigraphy and -28.9% and 17.3% for CT. The percentage of error of CT (15.4%) was comparable with that of scintigraphy (17.8%). CONCLUSIONS:Dual-energy perfusion CT was more accurate than perfusion scintigraphy was for predicting postoperative lung function. 10.1097/RLI.0b013e318289fa55
Quantitative lobar pulmonary perfusion assessment on dual-energy CT pulmonary angiography: applications in pulmonary embolism. Singh Ramandeep,Nie Ryan Zipan,Homayounieh Fatemeh,Schmidt Bernhard,Flohr Thomas,Kalra Mannudeep K European radiology PURPOSE:To assess quantitative lobar pulmonary perfusion on DECT-PA in patients with and without pulmonary embolism (PE). MATERIALS AND METHODS:Our retrospective study included 88 adult patients (mean age 56 ± 19 years; 38 men, 50 women) who underwent DECT-PA (40 PE present; 48 PE absent) on a 384-slice, third-generation, dual-source CT. All DECT-PA examinations were reviewed to record the presence and location of occlusive and non-occlusive PE. Transverse thin (1 mm) DECT images (80/150 kV) were de-identified and exported offline for processing on a stand-alone deep learning-based prototype for automatic lung lobe segmentation and to obtain the mean attenuation numbers (in HU), contrast amount (in mg), and normalized iodine concentration per lung and lobe. The zonal volumes and mean enhancement were obtained from the Lung Analysis™ application. Data were analyzed with receiver operating characteristics (ROC) and analysis of variance (ANOVA). RESULTS:The automatic lung lobe segmentation was accurate in all DECT-PA (88; 100%). Both lobar and zonal perfusions were significantly lower in patients with PE compared with those without PE (p < 0.0001). The mean attenuation numbers, contrast amounts, and normalized iodine concentrations in different lobes were significantly lower in the patients with PE compared with those in the patients without PE (AUC 0.70-0.78; p < 0.0001). Patients with occlusive PE had significantly lower quantitative perfusion compared with those without occlusive PE (p < 0.0001). CONCLUSION:The deep learning-based prototype enables accurate lung lobe segmentation and assessment of quantitative lobar perfusion from DECT-PA. KEY POINTS:• Deep learning-based prototype enables accurate lung lobe segmentation and assessment of quantitative lobar perfusion from DECT-PA. • Quantitative lobar perfusion parameters (AUC up to 0.78) have a higher predicting presence of PE on DECT-PA examinations compared with the zonal perfusion parameters (AUC up to 0.72). • The lobar-normalized iodine concentration has the highest AUC for both presence of PE and for differentiating occlusive and non-occlusive PE. 10.1007/s00330-019-06607-9
Dual-energy computed tomography for pre-surgical identification of adenocarcinoma subtypes. Translational lung cancer research 10.21037/tlcr.2020.03.18
Comparison of the effect of radiation exposure from dual-energy CT versus single-energy CT on double-strand breaks at CT pulmonary angiography. Tao Shu Min,Li Xie,Schoepf U Joseph,Nance John W,Jacobs Brian E,Zhou Chang Sheng,Gu Hai Feng,Lu Meng Jie,Lu Guang Ming,Zhang Long Jiang European journal of radiology PURPOSE:To compare the effect of dual-source dual-energy CT versus single-energy CT on DNA double-strand breaks (DSBs) in blood lymphocytes at CT pulmonary angiography (CTPA). METHODS AND MATERIALS:Sixty-two patients underwent either dual-energy CTPA (Group 1: n = 21, 80/Sn140 kVp, 89/38 mAs; Group 2: n = 20, 100/Sn140 kVp, 89/76 mAs) or single-energy CTPA (Group 3: n = 21, 120 kVp, 110 mAs). Blood samples were obtained before and 5 min after CTPA. DSBs were assessed with fluorescence microscopy and Kruskal-Walls tests were used to compare DSBs levels among groups. Volume CT dose index (CTDIvol), dose length product (DLP) and organ radiation dose were compared using ANOVA. RESULTS:There were increased excess DSB foci per lymphocyte 5 min after CTPA examinations in three groups (Group 1: P = .001; Group 2: P = .001; Group 3: P = .006). There were no differences among groups regarding excess DSB foci/cell and percentage of excess DSBs (Group 1, 23%; Group 2, 24%; Group 3, 20%; P = .932). CTDIvol, DLP and organ radiation dose in Group 1 were the lowest among the groups (all P < .001). CONCLUSION:DSB is increased following dual-source and single-source CTPA, while dual-source dual-energy CT protocols do not increase the estimated radiation dose and also do not result in a higher incidence of DNA DSBs in patients undergoing CTPA. 10.1016/j.ejrad.2018.02.002
Acquisition time, radiation dose, subjective and objective image quality of dual-source CT scanners in acute pulmonary embolism: a comparative study. Abdellatif Waleed,Esslinger Eric,Kobes Kevin,Wong Amanda,Powell Jennifer,Ali Ismail Tawakol,Andrews Gordon,Nicolaou Savvas European radiology OBJECTIVES:To compare the scan acquisition time, radiation dose, subjective and objective image quality of two dual-source CT scanners (DSCT) for detection of acute pulmonary embolism. METHODS:Two hundred twenty-one scans performed on the 2nd-generation DSCT and 354 scans on the 3rd-generation DSCT were included in this large retrospective study. In a randomized blinded design, two radiologists independently reviewed the scans using a 5-point Likert scale. Radiation dose and objective image quality parameters were calculated. RESULTS:Mean acquisition time was significantly lower in the 3rd-generation DSCT (2.81 s ± 0.1 in comparison with 9.7 s ± 0.15 [mean ± SD] respectively; p < 0.0001) with the 3rd generation 3.4 times faster. The mean subjective image quality score was 4.33/5 and 4/5 for the 3rd- and 2nd-generation DSCT respectively (p < 0.0001) with strong interobserver reliability agreement. DLP, CTDI, and ED were significantly lower in the 3rd than the 2nd generation (175.6 ± 63.7 mGy cm; 5.3 ± 1.9 mGy and 2.8 ± 1.2 mSv in comparison with 266 ± 255 mGy.cm; 7.8 ± 2.2 mGy and 3.8 ± 4.3 mSv). Noise was significantly lower in the 3rd generation (p < 0.01). Signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and figure of merit (FOM), a dose-insensitive index for CNR, were significantly higher in the 3rd-generation DSCT (33.5 ± 23.4; 29.0 ± 21.3 and 543.7 ± 1037 in comparison with 23.4 ± 17.7; 19.4 ± 16.0 and 170.5 ± 284.3). CONCLUSION:Objective and subjective image quality are significantly higher on the 3rd-generation DSCT with significantly lower mean acquisition time and radiation dose. KEY POINTS:• The 3rd-generation DSCT scanner provides an improved image quality, less perceived artifacts, and lower radiation dose in comparison with the 2nd-generation DSCT, when operating in dual-energy (DE) mode. • The 3.4-times-faster 3rd-generation DSCT scanner can be of particular value in patients with chronic lung diseases or breathing difficulties that prevent adequate breathhold. 10.1007/s00330-019-06650-6
Advances for Pulmonary Functional Imaging: Dual-Energy Computed Tomography for Pulmonary Functional Imaging. Diagnostics (Basel, Switzerland) Dual-energy computed tomography (DECT) can improve the differentiation of material by using two different X-ray energy spectra, and may provide new imaging techniques to diagnostic radiology to overcome the limitations of conventional CT in characterizing tissue. Some techniques have used dual-energy imaging, which mainly includes dual-sourced, rapid kVp switching, dual-layer detectors, and split-filter imaging. In iodine images, images of the lung's perfused blood volume (PBV) based on DECT have been applied in patients with pulmonary embolism to obtain both images of the PE occluding the pulmonary artery and the consequent perfusion defects in the lung's parenchyma. PBV images of the lung also have the potential to indicate the severity of PE, including chronic thromboembolic pulmonary hypertension. Virtual monochromatic imaging can improve the accuracy of diagnosing pulmonary vascular diseases by optimizing kiloelectronvolt settings for various purposes. Iodine images also could provide a new approach in the area of thoracic oncology, for example, for the characterization of pulmonary nodules and mediastinal lymph nodes. DECT-based lung ventilation imaging is also available with noble gases with high atomic numbers, such as xenon, which is similar to iodine. A ventilation map of the lung can be used to image various pulmonary diseases such as chronic obstructive pulmonary disease. 10.3390/diagnostics13132295
Trends in radiation dose and image quality for pediatric patients with a multidetector CT and a third-generation dual-source dual-energy CT. Agostini Andrea,Mari Alberto,Lanza Cecilia,Schicchi Nicolo',Borgheresi Alessandra,Maggi Stefania,Giovagnoni Andrea La Radiologia medica AIM:To provide an overview on dose reduction and image quality after the installation of a third-generation dual-source CT (dsCT) in a Pediatric Radiology Department. MATERIALS AND METHODS:We included pediatric patients (< 20 years old) undergoing CT for oncological staging (neck, chest and abdomen) or low-dose chest CT for lung diseases. Each of these two groups were further divided in two age groups (≤ or > 10 years old) including patients scanned in the same period of two consecutive years, in 2017 with a 16-row LightSpeed CT (GE Healthcare) or in 2018 with a Somatom Force dsCT (Siemens Healthineers). Technical parameters such as kVp, mAs, slice thickness, exposure times and dose indicators were retrieved and compared. Image quality was evaluated in consensus by two radiologists on a five-point semiquantitative scale. Nonparametric tests were used. RESULTS:In oncological patients, significantly lower kVp and tube current with better image quality were achieved with the dsCT. Radiation dose (total DLP) was 5-6 times lower with dsCT, thanks also to virtual non-contrast images. In low-dose chest CT, the frequent use of tin filter required higher tube current; a total DLP 3 times lower was achieved with dsCT in patients ≤ 10 years old. The image quality was better with the dsCT in low-dose chest CT protocols. CONCLUSION:The third-generation dsCT provides high-quality images with reduced motion artifacts at lower dose. 10.1007/s11547-019-01037-5
Value of Dual-energy Lung Perfusion Imaging Using a Dual-source CT System for the Pulmonary Embolism. Zhang Jinshan,Cai Jing,Liu Shulan,Zhang Xianmei Open life sciences Objective:To investigate the diagnostic value of dual-energy lung perfusion imaging (DEPI) using a dual-source CT system for the pulmonary embolism (PE). Methods:50 patients in high acute PE prevalence were enrolled to accept the DEPI (lung perfusion image and CTA image of pulmonary artery acquired through the Dual Energy software) and emergent DSA angiography (golden diagnostic criterion). Results:Patients using CT had significantly reduced examination duration and dosage of contrast agent than those using DSA examination, ( < .). In total, 260 pulmonary arteries and 1020 pulmonary segments were examined through CTA, in which embolisms were identified in 50 lobes of lung, 108 pulmonary segments and 82 sub-segments. Reduction or lack of perfusion was identified through DEPI in 48 lobes of lung (concordance rate of 96.0%), 103 pulmonary segments (concordance rate of 95.4%) and 78 subsegments (concordance rate of 95.1%). The comparison of embolism quantity and morphological characteristics of pulmonary artery between CTA images and DEPI images showed no statistically significant difference. Conclusion:Better application value can be achieved in the diagnosis of pulmonary embolism by dual-energy lung perfusion imaging using a dual-source CT system. 10.1515/biol-2018-0015
Correlation of dual-source computed tomography/dual-energy imaging with pathological grading of lung adenocarcinoma and its clinical value. Jiang Haifeng,Li Xiao Pakistan journal of medical sciences OBJECTIVE:To explore the correlation of dual-source computed tomography (DSCT)/dual-energy imaging with pathological grading of lung adenocarcinoma. METHODS:A total of 47 patients with lung adenocarcinoma were selected. Tissues were histopathologically confirmed by routine DSCT scanning and dual-energy enhanced scanning. Arterial-phase and venous-phase iodine distribution images and single-energy images at 40-190 keV were obtained. The region of interest was outlined to obtain CT values. The iodine concentrations of each tumor in two phases were recorded to calculate normalized iodine concentrations (NICs). RESULTS:The maximum diameter and minimum diameter of tumors in low differentiation (LD) group were significantly higher than those of high differentiation (HD) group (P<0.05). In LD group, 70.8% of margins were lobulated, which significantly exceeded that of HD group (30.4%) (P<0.05). Besides, 26.1% of patients in HD group were complicated with ground-glass opacity, which was significantly higher than that of LD group (4.2%) (P<0.05). In venous phase, there were significant differences between the two groups at low energy levels (40-70 keV) (P<0.05). At high energy levels (80-190 keV), the CT values of LD group were slightly higher than those of HD group. In arterial and venous phases, NICs of HD group were lower than those of LD group (P>0.05). CONCLUSION:HD and LD groups could be predictably distinguished by single-energy images at low energy levels (40-70 keV) in the venous phase. Quantitative analysis of NIC in the venous phase is also valuable for predicting the pathological grade of lung adenocarcinoma. 10.12669/pjms.336.13320
Correlation study between dual source CT perfusion imaging and the microvascular composition of solitary pulmonary nodules. Wang Meng,Li Bangguo,Sun Hui,Huang Tingting,Zhang Xuemei,Jin Kaiyuan,Wang Feng,Luo Xianli Lung cancer (Amsterdam, Netherlands) OBJECTIVE:To explore the correlation between dual source computed tomography perfusion imaging (CTPI) and microvascular parameters, and evaluate the value of CTPI in the differential diagnosis of solitary pulmonary nodule (SPN). METHODS:65 consecutive patients with SPN who successfully underwent pre-operative CT perfusion imaging with dual source CT and received a final diagnosis by postoperative pathology. The cases were divided into malignant, benign and inflammatory groups according to the pathological results. CT perfusion parameters, such as blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface (PMB) were obtained by performing CTPI of SPNs. The postoperative specimens of SPNs were immunohistochemically stained for CD34 and SMA to detect microvessel density (MVD) and luminal vascular parameters, such as luminal vascular number (LVN), luminal vascular area (LVA) and luminal vascular perimeter (LVP). The receiver operating characteristic (ROC) curve was used to assess the diagnostic efficiency of CT perfusion parameter in diagnosing malignant SPNs. RESULTS:In these 65 cases, malignant, benign and inflammatory SPNs were respectively 39, 14 and 12 cases. Significant difference was observed in LVN/MVD, LVA and LVP among the three groups (P < 0.05). The correlation between CT perfusion parameters (BF, BV and PMB) and the luminal vascular parameters was stronger than that with MVD (P < 0.05). PMB has the strongest correlation with LVN/MVD. Using BF≥60ml/100ml/min, BV≥6.34ml/100ml and PMB≥13.35ml/100 ml/min for the diagnosis, the area under the curve (AUC) of the ROC curve was 0.760, the sensitivity was 82% and the specificity was 61%. CONCLUSIONS:The main indicators reflecting blood perfusion of SPN are the degree of lumen or maturity of microvessels (LVN, LVA and LVP), not just the number of microvessels (e.g. MVD). CT perfusion imaging can be used as an important method to non-invasively evaluate tumour angiogenesis and help to distinguish malignant SPNs from benign and inflammatory SPNs. 10.1016/j.lungcan.2019.02.013
Dual-source computed tomography of the lung with spectral shaping and advanced iterative reconstruction: potential for maximum radiation dose reduction. Wetzl Matthias,May Matthias S,Weinmann Daniel,Hammon Matthias,Treutlein Christoph,Zeilinger Martin,Kiefer Alexander,Trollmann Regina,Woelfle Joachim,Uder Michael,Rompel Oliver Pediatric radiology BACKGROUND:Radiation dose at CT should be as low as possible without compromising diagnostic quality. OBJECTIVE:To assess the potential for maximum dose reduction of pediatric lung dual-source CT with spectral shaping and advanced iterative reconstruction (ADMIRE). MATERIALS AND METHODS:We retrospectively analyzed dual-source CT acquisitions in a full-dose group (FD: 100 kV, 64 reference mAs) and in three groups with spectral shaping and differing reference mAs values (Sn: 100 kV, 96/64/32 reference mAs), each group consisting of 16 patients (age mean 11.5 years, standard deviation 4.8 years, median 12.8 years, range 1.3-18 years). Advanced iterative reconstruction of images was performed with different strengths (FD: ADMIRE Level 2; Sn: ADMIRE Levels 2, 3 and 4). We analyzed dose parameters and measured noise. Diagnostic confidence and detectability of lung lesions as well as anatomical structures were assessed using a Likert scale (from 1 [unacceptable] to 4 [fully acceptable]). RESULTS:Compared to full dose, effective dose was reduced to 16.7% in the Sn 96 group, 11.1% in Sn64, and 5.5% in Sn32 (P<0.001). Noise values of Sn64 did not statistically differ from those in FD (45.7 vs. 38.9 Hounsfield units [HU]; P=0.132), whereas noise was significantly higher in Sn32 compared to Sn64 (61.5 HU; P<0.001). A Likert score >3 was reached in Sn64 regarding diagnostic confidence (3.2) and detectability of lung lesions (3.3). For detectability of most anatomical structures, no significant differences were found between FD and Sn64 (P≥0.05). CONCLUSION:In pediatric lung dual-source CT, spectral shaping together with ADMIRE 4 enable radiation dose reduction to about 10% of a full-dose protocol while maintaining an acceptable diagnostic quality. 10.1007/s00247-020-04714-0
Photon-counting versus Dual-Source CT of Congenital Heart Defects in Neonates and Infants: Initial Experience. Radiology Background Photon-counting CT (PCCT) has been shown to improve cardiovascular CT imaging in adults. Data in neonates, infants, and young children under the age of 3 years are missing. Purpose To compare image quality and radiation dose of ultrahigh-pitch PCCT with that of ultrahigh-pitch dual-source CT (DSCT) in children suspected of having congenital heart defects. Materials and Methods This is a prospective analysis of existing clinical CT studies in children suspected of having congenital heart defects who underwent contrast-enhanced PCCT or DSCT in the heart and thoracic aorta between January 2019 and October 2022. CT dose index and dose-length product were used to calculate effective radiation dose. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated by standardized region-of-interest analysis. SNR and CNR dose ratios were calculated. Visual image quality was assessed by four independent readers on a five-point scale: 5, excellent or absent; 4, good or minimal; 3, moderate; 2, limited or substantial; and 1, poor or massive. Results Contrast-enhanced PCCT ( = 30) or DSCT ( = 84) was performed in 113 children (55 female and 58 male participants; median age, 66 days [IQR, 15-270]; median height, 56 cm [IQR, 52-67]; and median weight, 4.5 kg [IQR, 3.4-7.1]). A diagnostic image quality score of at least 3 was obtained in 29 of 30 (97%) with PCCT versus 65 of 84 (77%) with DSCT. Mean overall image quality ratings were higher for PCCT versus DSCT (4.17 vs 3.16, respectively; < .001). SNR and CNR were higher for PCCT versus DSCT with SNR (46.3 ± 16.3 vs 29.9 ± 15.3, respectively; .007) and CNR (62.0 ± 50.3 vs 37.2 ± 20.8, respectively; = .001). Mean effective radiation doses were similar for PCCT and DSCT (0.50 mSv vs 0.52 mSv; = .47). Conclusion At a similar radiation dose, PCCT offers a higher SNR and CNR and thus better cardiovascular imaging quality than DSCT in children suspected of having cardiac heart defects. © RSNA, 2023. 10.1148/radiol.223088
Lung dual energy CT: Impact of different technological solutions on quantitative analysis. European journal of radiology PURPOSE:To evaluated the accuracy of spectral parameters quantification of four different CT scanners in dual energy examinations of the lung using a dedicated phantom. METHOD:Measurements were made with different technologies of the same vendor: one dual source CT scanner (DSCT), one TwinBeam (i.e. split filter) and two sequential acquisition single source scanners (SSCT). Angular separation of Calcium and Iodine signals were calculated from scatter plots of low-kVp versus high-kVp HUs. Electron density (ρe), effective atomic number (Zeff) and Iodine concentration (Iconc) were measured using Syngo.via software. Accuracy (A) of ρe, Zeff and Iconc was evaluated as the absolute percentage difference (D%) between reference values and measured ones, while precision (P) was evaluated as the variability σ obtained by repeating the measurement with different acquisition/reconstruction settings. RESULTS:Angular separation was significantly larger for DSCT (α = 9.7°) and for sequential SSCT (α = 9.9°) systems. TwinBeam was less performing in material separation (α = 5.0°). The lowest average A was observed for TwinBeam (A = [4.7 ± 1.0], A = [9.1 ± 3.1], A = [19.4 ± 4.4]), while the best average A was obtained for Flash (A = [1.8 ± 0.4], A = [3.5 ± 0.7], A = [7.3 ± 1.8]). TwinBeam presented inferior average P (P = [0.6 ± 0.1], P = [1.1 ± 0.2], P = [10.9 ± 4.9]), while other technologies demonstrate a comparable average. CONCLUSIONS:Different technologies performed material separation and spectral parameter quantification with different degrees of accuracy and precision. DSCT performed better while TwinBeam demonstrated not excellent performance. Iodine concentration measurements exhibited high variability due to low Iodine absolute content in lung nodules, thus limiting its clinical usefulness in pulmonary applications. 10.1016/j.ejrad.2023.110812
Comparison of serum tumor markers combined with dual-source CT in the diagnosis of lung cancer. Minerva medica BACKGROUND:The purpose of this study is to explore the clinical value of serum tumor markers combined with dual-source CT scanning in the diagnosis of lung cancer. METHODS:One hundred-two patients with lung cancer (malignant tumor group), 50 patients with benign lesions (benign control group) and 50 healthy patients (normal control group) were selected as the research objects. The levels of serum carcinoembryonic antigen (CEA), cytokeratin 19 fragment antigen 21-1 (CYFRA21-1) and gastrin releasing peptide precursor 31-98 (Pro-GRP31-98) were detected using the electrochemiluminescence and enzyme-linked immunoassay in three groups of people. Simultaneously, Siemens' second-generation dual-source CT (Siemens AG, Munich, Germany) is used to scan the lungs of patients with lung cancer and benign lesions. Retrospective statistical analysis is utilized to explore the clinical value of serum tumor markers combined with dual-source CT examination in the diagnosis of lung cancer. RESULTS:The levels of serum CEA, CYFRA21-1 and Pro-GRP31-98 in lung cancer patients were significantly higher than those in the benign control group and normal control group, and the difference was statistically significant (P<0.01). There was no statistical difference between the benign control group and the normal control group (P>0.05). The levels of serum CEA, CYFRA21-1, Pro-GRP31-98 had no significant correlation with the age, sex, and tumor site of lung cancer patients (P>0.05). However, the levels of serum CEA, CYFRA21-1, Pro-GRP31-98 have an obvious correlation with tumor size, clinical stage, histological type, combined pleural effusion, recurrence and metastasis after treatment (P<0.05). CT scans of 102 lung cancer patients showed 35 cases of central type, 67 cases of peripheral type, 71 cases with tumor diameter >5cm, 31 cases of ≤5cm and 67 cases of lymph node metastasis. The sensitivities of CEA, CYFRA21-1, Pro-GRP31-98, and dual-source CT in the diagnosis of lung cancer were 64.70%, 60.11%, 56.86% and 77.45%, and the accuracy was 75.00%, 72.37%, 69.74% and 82.89%, respectively. Compared with a single examination, the sensitivity and accuracy of combined examination for the diagnosis of lung cancer were significantly improved, which were 95.10% and 92.76%, respectively. CONCLUSIONS:Joint examinations can effectively improve the rate of lung cancer diagnosis. 10.23736/S0026-4806.21.07124-X
Third-generation dual-source dual-energy CT in pediatric congenital heart disease patients: state-of-the-art. Schicchi Nicolò,Fogante Marco,Esposto Pirani Paolo,Agliata Giacomo,Basile Maria Chiara,Oliva Matteo,Agostini Andrea,Giovagnoni Andrea La Radiologia medica Cardiovascular computer tomography (CT) in pediatric congenital heart disease (CHD) patients is often challenging. This might be due to limited patient cooperation, the high heart rate, the complexity and variety of diseases and the need for radiation dose minimization. The recent developments in CT technology with the introduction of the third-generation dual-source (DS) dual-energy (DE) CT scanners well suited to respond to these challenges. DSCT is characterized by high-pitch, long anatomic coverage and a more flexible electrocardiogram-synchronized scan. DE provides additional clinical information about vascular structures, myocardial and lung perfusion and allows artifacts reduction. These advances have increased clinical indications and modified CT protocol for pediatric CHD patients. In our hospital, DSCT with DE technology has rapidly become an important imaging technique for both pre- and postoperative management of pediatric patients with CHDs. The aim of this article is to describe the state-of-the-art in DSCT protocol with DE technology in pediatric CHD patients, providing some case examples of our experience over an 18-month period. 10.1007/s11547-019-01097-7