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Sample records for dual source ct

  1. Cerebral artery evaluation of dual energy CT angiography with dual source CT

    Institute of Scientific and Technical Information of China (English)

    MA Rui; LIU Cheng; DENG Kai; SONG Shao-juan; WANG Dao-ping; HUANG Ling

    2010-01-01

    Background Conventional computed tomography angiography (CTA) is time consuming, user-dependent and has poor image quality in skull base region. This study assessed the feasibility of a new method, dual energy CTA for depicting the cerebral artery.Methods Phantom scan was done with head CTA sequences on dual source CT and 64 spiral CT for radiation dose calculation. Dual energy CTA was done with dual source CT on 36 patients who were suspected of having cerebral vascular disease. Three series axial images in 0.75 mm thick, 0.4 mm increment were acquired, which were named with 80 kV, 140 kV and merged images; 80 kV and 140 kV images were transferred into dual energy software, and maximum intensity projection (MIP) image was generated quickly by dual energy bone remove (DEBR group); merged images were transferred into In Space software to acquire MIP image through manual conventional bone remove (CoBR group). Post processing time and reading time were compared. Image qualities of the two groups were compared, mainly focusing on skull base segments of internal carotid artery and bone subtraction. ANOVA and SNK tests were applied for radiation dose comparison. Student's t test and Wilcoxon rank sum test were applied for assessing differences between data for significance. Cohen's kappa was used for interobserver agreement. Results Radiation dose of phantom scan showed dual energy CTA was between digital bone subtraction and conventional CTA. The post processing time and reading time were much shorter in DEBR than CoBR, and image quality in skull base was much higher in DEBR than CoBR (P0.5). Interobserver agreement for all vessel segments was excellent (kappa=0.97). Conclusions Dual energy CTA is a reliable, new modality for depicting cerebral artery, overcoming the limitation of conventional CTA in the skull base region. It can save much time in post processing and reading than conventional CTA.

  2. Thoracic applications of dual-source CT technology.

    Science.gov (United States)

    Boroto, Kahimano; Remy-Jardin, Martine; Flohr, Thomas; Faivre, Jean-Baptiste; Pansini, Vittorio; Tacelli, Nunzia; Schmidt, Bernhard; Gorgos, Andrei; Remy, Jacques

    2008-12-01

    Among the various imaging modalities available, CT has remained over time the core imaging technique for the evaluation of respiratory disorders. The recent advent of dual-source CT offers innovative approaches to investigate thoracic diseases, based on the use of one or two tubes as well as single or dual energy to scan the entire thorax. Two major options can be used in clinical practice with promising results. Dual source, single-energy scanning allows scanning of the entire thorax with ultra-high temporal resolution which opens the field of integrated cardiothoracic imaging without ECG gating as well as optimized evaluation of pediatric and adult patients with limited ability to cooperate. Dual-source, dual-energy acquisitions represent another very innovative means of investigating respiratory disorders, adding tissue characterization and functional analysis to morphological evaluation. The purpose of this review article is to provide results on preliminary experiences with the above-mentioned scanning conditions with dual-source CT and to envisage potential forthcoming applications in the field of thoracic imaging.

  3. Initial experience of dual-energy lung perfusion CT using a dual-source CT system in children

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    Goo, Hyun Woo [University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Songpa-gu, Seoul (Korea)

    2010-09-15

    Initial experience of dual-source dual-energy (DE) lung perfusion CT in children is described. In addition to traditional identification of pulmonary emboli, the assessment of lung perfusion is technically feasible with dual-source DE CT in children with acceptable radiation dose. This article describes how to perform dual-source DE lung perfusion CT in children, including the optimization of intravenous injection method and CT dose parameters. How to produce weighted-average CT images for the assessment of pulmonary emboli and colour-coded perfusion maps for the assessment of regional lung perfusion is also detailed. Lung perfusion status can then be evaluated on perfusion maps by means of either qualitative or quantitative analysis. Potential advantages and disadvantages of this emerging CT technique compared to lung perfusion scintigraphy and cardiac MRI are discussed. (orig.)

  4. The utilization of dual source CT in imaging of polytrauma

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    Nicolaou, S. [University of British Columbia, Vancouver General Hospital, Department of Radiology, 899 West 12th Avenue, Vancouver, British Columbia, V5Z1M9 (Canada)], E-mail: savvas.nicolaou@vch.ca; Eftekhari, A.; Sedlic, T.; Hou, D.J.; Mudri, M.J.; Aldrich, John; Louis, L. [University of British Columbia, Vancouver General Hospital, Department of Radiology, 899 West 12th Avenue, Vancouver, British Columbia, V5Z1M9 (Canada)

    2008-12-15

    Despite the growing role of imaging, trauma remains the leading cause of death in people below the age of 45 years in the western industrialized countries. Trauma has been touted as the largest epidemic in the 20th century. The advent of MDCT has been the greatest advance in trauma care in the last 25 years. However, there are still challenges in CT imaging of the polytrauma individual including time restraints, diagnostic errors, radiation dose effects and bridging the gap between anatomy and physiology. This article will analyze these challenges and provide possible solutions offered by the unique design of the dual source CT scanner.

  5. Dual energy with dual source CT and kVp switching with single source CT: a comparison of dual energy performance

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    Grasruck, M.; Kappler, S.; Reinwand, M.; Stierstorfer, K.

    2009-02-01

    Stimulated by the introduction of clinical dual source CT, the interest in dual energy methods has been increasing in the past years. Whereas the potential of material decomposition by dual energy methods is known since the early 1980ies, the realization of dual energy methods is a wide field of today's research. Energy separation can be achieved with energy selective detectors or by varying X-ray source spectra. This paper focuses on dual energy techniques with varying X-ray spectra. These can be provided by dual source CT devices, operated with different kVp settings on each tube. Excellent spectral separation is the key property for use in clinical routine. The drawback of higher cost for two tubes and two detectors leads to an alternative realization, where a single source CT yields different spectra by fast kVp switching from reading to reading. This provides access to dual-energy methods in single source CT. However, this technique comes with some intrinsic limitations. The maximum X-ray flux is reduced in comparison to the dual source system. The kVp rise and fall time between each reading reduces the spectral separation. In comparison to dual source CT, for a constant number of projections per energy spectrum the temporal resolution is reduced; a reasonable trade of between reduced numbers of projection and limited temporal resolution has to be found. The overall dual energy performance is the guiding line for our investigations. We present simulations and measurements which benchmark both solutions in terms of spectral behavior, especially of spectral separation.

  6. Correlation Between Dual-energy and Perfusion CT in Patients with Focal Liver Lesions Using Third-generation Dual-source CT Scanner.

    Science.gov (United States)

    Xu, Jia; Zheng, Yongchang; Wang, Xuan; Xue, Huadan; Wang, Shitian; Liang, Jixiang; Jin, Zhengyu

    2017-02-20

    Objective To compare measurements of dual-energy CT iodine map parameters and liver perfusion CT parameters in patients with focal liver lesions using a third-generation dual-source CT scanner. Methods Between November 2015 and August 2016,33 patients with non-cystic focal lesions of liver were enrolled in this study. CT examinations were performed with a third-generation dual-source CT. The study CT protocol included a perfusion CT and dual-energy arterial and portal venous scans,with a time interval of 15 minutes. Iodine attenuation was measured at five region of interests including areas of high,medium,and low density within the lesion,as well as right and left liver parenchyma from the iodine map,while arterial liver perfusion (ALP),portal venous liver perfusion (PVP),and hepatic perfusion index (HPI) at the same location were measured from perfusion CT. The Pearson product-moment correlation coefficient was used to evaluate the relationship between iodine attenuation and perfusion parameters. Results The iodine attenuation at arterial phase showed significant intra-individual correlation with ALP (r=0.812,95% CI=0.728-0.885,Pperfusion CT [(14.53±0.45)mSv](t=25.212,P<0.001). Conclusion Iodine attenuation from arterial phase of dual energy CT demonstrates significant correlation with ALP and PVP,and iodine attenuation from portal venous phase demonstrates significant correlation with PVP.

  7. Attenuation-based characterization of coronary atherosclerotic plaque: Comparison of dual source and dual energy CT with single-source CT and histopathology

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    Henzler, Thomas, E-mail: Thomas.Henzler@umm.de [Department of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim - Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim (Germany); Porubsky, Stefan [Department of Pathology, University Medical Center Mannheim, Medical Faculty Mannheim - Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim (Germany); Kayed, Hany [Department of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim - Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim (Germany); Harder, Nils [Department of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim - Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim (Germany); Department of Pathology, University Medical Center Mannheim, Medical Faculty Mannheim - Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim (Germany); Krissak, U. Radko; Meyer, Mathias [Department of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim - Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim (Germany); Sueselbeck, Tim [1st Department of Medicine University Medical Center Mannheim, Medical Faculty Mannheim - Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim (Germany); Marx, Alexander [Department of Pathology, University Medical Center Mannheim, Medical Faculty Mannheim - Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim (Germany); Michaely, Henrik [Department of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim - Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim (Germany); Schoepf, U. Joseph [Department of Radiology and Radiological Science, Medical University of South Carolina, 169 Ashley Avenue, Charleston (United States)

    2011-10-15

    Objective: To compare different CT acquisition techniques regarding for attenuation-based characterization of coronary atherosclerotic plaques using histopathology as the standard of reference. Materials and methods: In a post mortem study 17 human hearts were studied with dual-source CT (DSCT) and dual energy CT (DECT) mode on a DSCT as well as with 16-slice single-source CT (SSCT). At autopsy, atherosclerotic lesions were cut at 5 {mu}m sections. Histopathologic classification of the plaques according to the American Heart Association (AHA) criteria was performed by two pathologists. Attenuation values of all plaques were measured in DSCT, DECT and SSCT studies, respectively and classified based on attenuation according to modified AHA criteria. Results: 58 coronary plaques were identified at autopsy. Regardless of the CT technique only 52/58 plaques were found at CT (sensitivity = 89.6%). There was no significant difference between the mean attenuation values of different plaque types between DSCT, DECT, and SSCT: type IV: 11 HU/8 HU/19 HU; type Va: 44 HU/45 HU/52 HU; type Vb: 1088 HU/966 HU/1079 HU). The sensitivity for correct classification varied depending on the plaque type (type II = 0%, type III = 0%, type IV = 43%, type Va = 58%, Vb = 97%). Conclusion: Independent of the used acquisition technique, SSCT, DSCT and DECT show similar results for attenuation-based characterization of atherosclerotic coronary plaques.

  8. Diagnostic value of dual-source CT in Kawasaki disease

    Institute of Scientific and Technical Information of China (English)

    CHAO Bao-ting; WANG Xi-ming; WU Le-bin; CHEN Jie; CHENG Zhao-ping; WU Da-wei; DUAN Yan-hua

    2010-01-01

    Background Doppler color echocardiography is a common method for detecting coronary artery lesions in patients with Kawasaki disease(KD).However,the diagnostic accuracy for the whole coronary artery lesions is limited.The purpose of this study was to compare the diagnostic value of dual-source computed tomography (DSCT) and Doppler color echocardiography for the assessment of coronary artery lesions caused by KD.Methods Sixteen patients,12 with typical KD and 4 with atypical KD,underwent DSCT and Doppler color echocardiography.The position and internal diameter of each coronary artery lesion was measured.Correlation analysis was used to compare the diagnostic value of the two imaging modalities.Results ln the typical KD group, seven patients did not have any coronary artery Iesion as confirmed by both DSCT scans and Doppler color echocardiography;in four patients proximal coronary artery injuries were identified by both modalities;in one patient an aneurysm in the middle and distal segments of the coronary artery was detected by DSCT but was negative in Doppler color echocardiography.In the atypical KD group,three cases showed the same results with both modalities,while one case with coronary artery stenosis in the middle segment was identified by DSCT but not detected by Doppler color echocardiography.There was a good correlation between the two imaging modalities(Kappa value,0.768(≥0.75)).Conclusion DSCT coronary artery angiography is an accurate,non-invasive,and valuable technique for detecting and following up coronary artery lesions in patients with KD.

  9. [The value of dual-source dual-energy CT with iodine overlay in the diagnosis of acute necrotizing pancreatitis].

    Science.gov (United States)

    Yuan, Yuan; Huang, Zi-Xing; Li, Zhen-Lin; Song, Bin; Deng, Li-Ping

    2012-07-01

    To investigate the clinical value of dual-source computed tomography dual-energy Iodine overlay technique in the imaging diagnosis of acute necrotizing pancreatitis. The imaging data were retrospectively analyzed in 67 cases of acute necrotizing pancreatitis underwent contrast-enhanced dual-source dual-energy CT in portal venous phase. The CT imaging parameters, including the difference of CT value between pancreatic parenchyma and necrotic lesion, contrast-to-noise ratio of pancreatic parenchyma-to-necrosis, area of pancreatic necrosis and score of subjective diagnosis, were measured and assessed on CT images of 80 kV, 140 kV, weighted-average 120 kV as well as Iodine overlay. The differences of CT value between pancreatic parenchyma and necrosis in the images of 80 kV, 140 kV, weighted-average 120 kV and Iodine overlay were (67.40 +/- 20.82) HU, (42.87 +/- 14.99) HU, (48.69 +/- 15.82) HU, (33.01 +/- 10.26) HU, respectively; contrast-to-noise ratios of pancreatic parenchyma-to-necrosis of each group were 8.36 +/- 3.58, 5.85 +/- 2.65, 7.68 +/- 3.51, 10.60 4.34; area of pancreatic necrosis of each group was (3.78 +/- 2.68) cm2, (3.28 +/- 2.59) cm2, (3.37 +/- 2.46) cm2, (2.42 +/- 1.98) cm2; the score of subjective diagnosis of each group was 3.88 +/- 0.33, 3.31 +/- 0.80, 3.58 +/- 0.66, 2.81 +/- 0.76, respectively. The four indexes in the images of Iodine overlay were significantly different from those of another three groups (P overlay was significantly higher than that of another three groups, while the difference of CT value, area of pancreatic necrosis and score of subjective diagnosis were lower. CONCLUSION; Dual-source CT dual-energy Iodine overlay is not helpful to improve subjective judgment in the diagnosis of pancreatic necrosis, but contributes to the display of hypoperfusion area around the necrosis.

  10. Coronary calcium screening with dual-source CT: reliability of ungated, high-pitch chest CT in comparison with dedicated calcium-scoring CT

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    Hutt, Antoine; Faivre, Jean-Baptiste; Remy, Jacques; Remy-Jardin, Martine [CHRU et Universite de Lille, Department of Thoracic Imaging, Hospital Calmette (EA 2694), Lille (France); Duhamel, Alain; Deken, Valerie [CHRU et Universite de Lille, Department of Biostatistics (EA 2694), Lille (France); Molinari, Francesco [Centre Hospitalier General de Tourcoing, Department of Radiology, Tourcoing (France)

    2016-06-15

    To investigate the reliability of ungated, high-pitch dual-source CT for coronary artery calcium (CAC) screening. One hundred and eighty-five smokers underwent a dual-source CT examination with acquisition of two sets of images during the same session: (a) ungated, high-pitch and high-temporal resolution acquisition over the entire thorax (i.e., chest CT); (b) prospectively ECG-triggered acquisition over the cardiac cavities (i.e., cardiac CT). Sensitivity and specificity of chest CT for detecting positive CAC scores were 96.4 % and 100 %, respectively. There was excellent inter-technique agreement for determining the quantitative CAC score (ICC = 0.986). The mean difference between the two techniques was 11.27, representing 1.81 % of the average of the two techniques. The inter-technique agreement for categorizing patients into the four ranks of severity was excellent (weighted kappa = 0.95; 95 % CI 0.93-0.98). The inter-technique differences for quantitative CAC scores did not correlate with BMI (r = 0.05, p = 0.575) or heart rate (r = -0.06, p = 0.95); 87.2 % of them were explained by differences at the level of the right coronary artery (RCA: 0.8718; LAD: 0.1008; LCx: 0.0139; LM: 0.0136). Ungated, high-pitch dual-source CT is a reliable imaging mode for CAC screening in the conditions of routine chest CT examinations. (orig.)

  11. 双源CT的临床应用进展%Development and Clinical Application of Dual-Source CT

    Institute of Scientific and Technical Information of China (English)

    徐辉; 殷信道; 吴旻

    2014-01-01

    In 2005 and 2008, Siemens launched the 昀rst and second generation Dual Source CT system. This paper reviews the basic structure, characteristics, advantages and application of Dual Source CT system.%2005年、2008年西门子相继推出第一代双源CT Definition(Dual Source Computed Tomography, DSCT)、第二代双源CT(SOMATOM De昀nition Flash),本文主要就双源CT的基本结构、特点、优势以及在临床应用方面的进展作一综述。

  12. Spatial Distribution of Iron Within the Normal Human Liver Using Dual-Source Dual-Energy CT Imaging.

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    Abadia, Andres F; Grant, Katharine L; Carey, Kathleen E; Bolch, Wesley E; Morin, Richard L

    2017-05-29

    Explore the potential of dual-source dual-energy (DSDE) computed tomography (CT) to retrospectively analyze the uniformity of iron distribution and establish iron concentration ranges and distribution patterns found in healthy livers. Ten mixtures consisting of an iron nitrate solution and deionized water were prepared in test tubes and scanned using a DSDE 128-slice CT system. Iron images were derived from a 3-material decomposition algorithm (optimized for the quantification of iron). A conversion factor (mg Fe/mL per Hounsfield unit) was calculated from this phantom study as the quotient of known tube concentrations and their corresponding CT values. Retrospective analysis was performed of patients who had undergone DSDE imaging for renal stones. Thirty-seven patients with normal liver function were randomly selected (mean age, 52.5 years). The examinations were processed for iron concentration. Multiple regions of interest were analyzed, and iron concentration (mg Fe/mL) and distribution was reported. The mean conversion factor obtained from the phantom study was 0.15 mg Fe/mL per Hounsfield unit. Whole-liver mean iron concentrations yielded a range of 0.0 to 2.91 mg Fe/mL, with 94.6% (35/37) of the patients exhibiting mean concentrations below 1.0 mg Fe/mL. The most important finding was that iron concentration was not uniform and patients exhibited regionally high concentrations (36/37). These regions of higher concentration were observed to be dominant in the middle-to-upper part of the liver (75%), medially (72.2%), and anteriorly (83.3%). Dual-source dual-energy CT can be used to assess the uniformity of iron distribution in healthy subjects. Applying similar techniques to unhealthy livers, future research may focus on the impact of hepatic iron content and distribution for noninvasive assessment in diseased subjects.

  13. Performance of turbo high-pitch dual-source CT for coronary CT angiography: first ex vivo and patient experience

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    Morsbach, Fabian; Gordic, Sonja; Husarik, Daniela; Frauenfelder, Thomas; Alkadhi, Hatem [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland); Desbiolles, Lotus; Leschka, Sebastian [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland); Kantonsspital St. Gallen, Divison of Radiology and Nuclear Medicine, St. Gallen (Switzerland); Schmidt, Bernhard; Allmendinger, Thomas [Siemens AG, Healthcare Sector, Forchheim (Germany); Wildermuth, Simon [Kantonsspital St. Gallen, Divison of Radiology and Nuclear Medicine, St. Gallen (Switzerland)

    2014-08-15

    To evaluate image quality, maximal heart rate allowing for diagnostic imaging, and radiation dose of turbo high-pitch dual-source coronary computed tomographic angiography (CCTA). First, a cardiac motion phantom simulating heart rates (HRs) from 60-90 bpm in 5-bpm steps was examined on a third-generation dual-source 192-slice CT (prospective ECG-triggering, pitch 3.2; rotation time, 250 ms). Subjective image quality regarding the presence of motion artefacts was interpreted by two readers on a four-point scale (1, excellent; 4, non-diagnostic). Objective image quality was assessed by calculating distortion vectors. Thereafter, 20 consecutive patients (median, 50 years) undergoing clinically indicated CCTA were included. In the phantom study, image quality was rated diagnostic up to the HR75 bpm, with object distortion being 1 mm or less. Distortion increased above 1 mm at HR of 80-90 bpm. Patients had a mean HR of 66 bpm (47-78 bpm). Coronary segments were of diagnostic image quality for all patients with HR up to 73 bpm. Average effective radiation dose in patients was 0.6 ± 0.3 mSv. Our combined phantom and patient study indicates that CCTA with turbo high-pitch third-generation dual-source 192-slice CT can be performed at HR up to 75 bpm while maintaining diagnostic image quality, being associated with an average radiation dose of 0.6 mSv. (orig.)

  14. Radiation dose levels in pediatric chest CT: experience in 499 children evaluated with dual-source single-energy CT

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    Martine, Remy-Jardin; Colas, Lucie; Jean-Baptiste, Faivre; Remy, Jacques [CHU Lille (EA 2694) University of Lille, Department of Thoracic Imaging, Hospital Calmette, Lille (France); Santangelo, Teresa [CHU Lille (EA 2694) University of Lille, Department of Thoracic Imaging, Hospital Calmette, Lille (France); Bambino Gesu Children' s Hospital, Department of Imaging, Rome (Italy); Duhamel, Alain [University of Lille (EA 2694), Department of Biostatistics, CHU Lille, Lille (France); Deschildre, Antoine [CHU Lille - University of Lille, Department of Pediatric Pulmonology, Lille (France)

    2017-02-15

    The availability of dual-source technology has introduced the possibility of scanning children at lower kVp with a high-pitch mode, combining high-speed data acquisition and high temporal resolution. To establish the radiation dose levels of dual-source, single-energy chest CT examinations in children. We retrospectively recorded the dose-length product (DLP) of 499 consecutive examinations obtained in children <50 kg, divided into five weight groups: group 1 (<10 kg, n = 129); group 2 (10-20 kg, n = 176); group 3 (20-30 kg, n = 99), group 4 (30-40 kg, n = 58) and group 5 (40-49 kg, n = 37). All CT examinations were performed with high temporal resolution (75 ms), a high-pitch mode and a weight-adapted selection of the milliamperage. CT examinations were obtained at 80 kVp with a milliamperage ranging between 40 mAs and 90 mAs, and a pitch of 2.0 (n = 162; 32.5%) or 3.0 (n = 337; 67.5%). The mean duration of data acquisition was 522.8 ± 192.0 ms (interquartile range 390 to 610; median 490). In the study population, the mean CT dose index volume (CTDIvol{sub 32}) was 0.83 mGy (standard deviation [SD] 0.20 mGy; interquartile range 0.72 to 0.94; median 0.78); the mean DLP{sub 32} was 21.4 mGy.cm (SD 9.1 mGy.cm; interquartile range 15 to 25; median 19.0); and the mean size-specific dose estimate (SSDE) was 1.7 mGy (SD 0.4 mGy; interquartile range 1.5 to 1.9; median 1.7). The DLP{sub 32}, CTDI{sub vol32} and SSDE were found to be statistically significant in the five weight categories (P < 0.0001). This study establishes the radiation dose levels for dual-source, single-kVp chest CT from a single center. In the five weight categories, the median values varied 15-37 mGy.cm for the DLP{sub 32}, 0.78-1.25 mGy for the CTDI{sub vol32} and 1.6-2.1 mGy for the SSDE. (orig.)

  15. High-pitch coronary CT angiography with third generation dual-source CT: limits of heart rate.

    Science.gov (United States)

    Gordic, Sonja; Husarik, Daniela B; Desbiolles, Lotus; Leschka, Sebastian; Frauenfelder, Thomas; Alkadhi, Hatem

    2014-08-01

    To determine the average heart rate (HR) and heart rate variability (HRV) required for diagnostic imaging of the coronary arteries in patients undergoing high-pitch CT-angiography (CTA) with third-generation dual-source CT. Fifty consecutive patients underwent CTA of the thoracic (n = 8) and thoracoabdominal (n = 42) aorta with third-generation dual-source 192-slice CT with prospective electrocardiography (ECG)-gating at a pitch of 3.2. No β-blockers were administered. Motion artifacts of coronary arteries were graded on a 4-point scale. Average HR and HRV were noted. The average HR was 66 ± 11 beats per minute (bpm) (range 45-96 bpm); the HRV was 7.3 ± 4.4 bpm (range 3-20 bpm). Interobserver agreement on grade of image quality for the 642 coronary segments evaluated by both observers was good (κ = 0.71). Diagnostic image quality was found for 608 of the 642 segments (95%) in 43 of 50 patients (86%). In 14% of the patients, image quality was nondiagnostic for at least one segment. HR (p = 0.001) was significantly higher in patients with at least one non-diagnostic segment compared to those without. There was no significant difference (p > 0.05) in HRV between patients with nondiagnostic segments and those with diagnostic images of all segments. All patients with a HR CT allows for coronary angiography in the prospectively ECG-gated high-pitch mode with diagnostic image quality at HR up to 70 bpm. HRV is not significantly related to image quality of coronary CTA.

  16. Clinical application of dual-source CT in the diagnosis of ALCAPA

    Institute of Scientific and Technical Information of China (English)

    程召平

    2014-01-01

    Objective To explore the clinical usefulness of anomalous origin of left coronary artery from the pulmonary artery(ALCAPA)by dual-source CT(DSCT)angiography.Methods A total of 10 patients(mean age5.1±5.0 yrs,age range 0.2-15 yrs;male 5)withALCAPA who underwent DSCT angiography and echocardiography were retrospectively included.Surgery was performed in 7 patients,and conventional cardiac angiography(CCA)in 4 patients.The subjective image quality was evaluated on a

  17. Dual-source CT coronary angiography in patients with atrial fibrillation: Comparison with single-source CT

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    Wang Yining [Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing (China)], E-mail: yiningpumc@hotmail.com; Zhang Zhuhua [Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing (China)], E-mail: yiningpumc@sina.com; Kong Lingyan [Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing (China)], E-mail: klyan78@hotmail.com; Song Lan [Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing (China)], E-mail: sallysonglan@sina.com; Merges, Reto D. [CT Research Collaboration, Siemens Ltd. (China)], E-mail: reto.merges@siemens.com; Chen Jiuhong [CT Research Collaboration, Siemens Ltd. (China)], E-mail: jiuhong.chen@siemens.com; Jin Zhengyu [Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing (China)], E-mail: jin_zhengyu@sina.com

    2008-12-15

    Objective: To evaluate the performance of dual-source computed tomography (DSCT) for the visualization of the coronary arteries in a population with atrial fibrillation (AF) compared to single-source CT (SSCT) and to explore the impact of patients' heart rate (HR) on image quality (IQ) and reconstruction timing. Methods: Thirty consecutive patients (11 male, 19 female; 69.0 {+-} 9.2 years old) with suspected coronary artery disease and permanent AF were examined on a DSCT scanner (120 kV, 400 mAs/rot, 0.33 s rotation time, 64 x 0.6 mm collimation, pitch 0.20-0.28, Siemens Somatom Definition). Patients were divided into two groups: low and medium HR group (HR {<=} 80 bpm, n = 14) and high HR group (HR > 80 bpm, n = 16). Five of the patients also underwent conventional coronary angiography (CAG). The raw data from both tube detector arrays were reconstructed as DSCT data using a routine algorithm (temporal resolution of 83 ms). The raw data from one tube detector array was reconstructed separately on the same system using a routine single source algorithm (temporal resolution of 83-165 ms) and defined as virtual SSCT data. Image quality was assessed using a four-point grading scale from excellent (1) to non-assessable (4). Results: IQ of the DSCT data was significantly better than that of the virtual SSCT data (mean score 1.33 {+-} 0.61 vs. 1.80 {+-} 1.02; Z = -8.755, P = 0.000). 98.6% of the segments shown in DSCT were diagnostic, compared with 89.9% of the segments in virtual SSCT, {chi}{sup 2} = 32.595, P = 0.000. In DSCT group, IQ of low HR group was also better than that of high HR group, although the difference was not as big (mean score 1.25 {+-} 0.52 vs. 1.38 {+-} 0.66; Z = -2.227, P = 0.026). The mean HR of low HR group and high HR group were 67.4 {+-} 8.5 beats per minute (bpm) and 94.2 {+-} 8.8 bpm (t = -8.499, P = 0.000). The range of the variation of HR was higher in high HR group than in low HR group (mean difference between maximum and minimum HR

  18. Image Quality and Radiation Dose for Prospectively Triggered Coronary CT Angiography: 128-Slice Single-Source CT versus First-Generation 64-Slice Dual-Source CT

    Science.gov (United States)

    Gu, Jin; Shi, He-Shui; Han, Ping; Yu, Jie; Ma, Gui-Na; Wu, Sheng

    2016-10-01

    This study sought to compare the image quality and radiation dose of coronary computed tomography angiography (CCTA) from prospectively triggered 128-slice CT (128-MSCT) versus dual-source 64-slice CT (DSCT). The study was approved by the Medical Ethics Committee at Tongji Medical College of Huazhong University of Science and Technology. Eighty consecutive patients with stable heart rates lower than 70 bpm were enrolled. Forty patients were scanned with 128-MSCT, and the other 40 patients were scanned with DSCT. Two radiologists independently assessed the image quality in segments (diameter >1 mm) according to a three-point scale (1: excellent; 2: moderate; 3: insufficient). The CCTA radiation dose was calculated. Eighty patients with 526 segments in the 128-MSCT group and 544 segments in the DSCT group were evaluated. The image quality 1, 2 and 3 scores were 91.6%, 6.9% and 1.5%, respectively, for the 128-MSCT group and 97.6%, 1.7% and 0.7%, respectively, for the DSCT group, and there was a statistically significant inter-group difference (P ≤ 0.001). The effective doses were 3.0 mSv in the 128-MSCT group and 4.5 mSv in the DSCT group (P ≤ 0.001). Compared with DSCT, CCTA with prospectively triggered 128-MSCT had adequate image quality and a 33.3% lower radiation dose.

  19. Volumetric evaluation of dual-energy perfusion CT by the presence of intrapulmonary clots using a 64-slice dual-source CT

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Munemasa; Nakashima, Yoshiteru; Kunihiro, Yoshie; Nakao, Sei; Matsunaga, Naofumi [Dept. of Radiology, Yamaguchi Univ. Graduate School of Medicine, Yamaguchi (Japan)], e-mail: radokada@yamaguchi-u.ac.jp; Morikage, Noriyasu [Medical Bioregulation Dept. of Organ Regulatory Surgery, Yamaguchi Univ. Graduate School of Medicine, Yamaguchi (Japan); Sano, Yuichi [Dept. of Radiology, Yamaguchi Univ. Hospital, Yamaguchi (Japan); Suga, Kazuyoshi [Dept. of Radiology, St Hills Hospital, Yamaguchi (Japan)

    2013-07-15

    Background: Dual-energy perfusion CT (DE{sub p}CT) directly represents the iodine distribution in lung parenchyma and low perfusion areas caused by intrapulmonary clots (IPCs) are visualized as low attenuation areas. Purpose: To evaluate if volumetric evaluation of DE{sub p}CT can be used as a predictor of right heart strain by the presence of IPCs. Material and Methods: One hundred and ninety-six patients suspected of having acute pulmonary embolism (PE) underwent DE{sub p}CT using a 64-slice dual-source CT. DE{sub p}CT images were three-dimensionally reconstructed with four threshold ranges: 1-120 HU (V{sub 120}), 1-15 HU (V{sub 15}), 1-10 HU (V{sub 10}), and 1-5 HU (V{sub 5}). Each relative ratio per V{sub 120} was expressed as the %V{sub 15}, %V{sub 10}, and %V{sub 5}. Volumetric data-sets were compared with D-dimer, pulmonary arterial (PA) pressure, right ventricular (RV) diameter, RV/left ventricular (RV/LV) diameter ratio, PA diameter, and PA/aorta (PA/Ao) diameter ratio. The areas under the ROC curves (AUCs) were examined for their relationship to the presence of IPCs. This study was approved by the local ethics committee. Results: PA pressure and D-dimer were significantly higher in the patients who had IPCs. In the patients with IPCs, V{sub 15}, V{sub 10}, V{sub 5}, %V{sub 15}, %V{sub 10}, and %V{sub 5} were also significantly higher than those without IPC (P = 0.001). %V{sub 5} had a better correlation with D-dimer (r = 0.30, P < 0.001) and RV/LV diameter ratio (r = 0.27, P < 0.001), and showed a higher AUC (0.73) than the other CT measurements. Conclusion: The volumetric evaluation by DE{sub p}CT had a correlation with D-dimer and RV/LV diameter ratio, and the relative ratio of volumetric CT measurements with a lower attenuation threshold might be recommended for the analysis of acute PE.

  20. Efficacy of a dynamic collimator for overranging dose reduction in a second- and third-generation dual source CT scanner

    NARCIS (Netherlands)

    R. Booij (Ronald); M.L. Dijkshoorn (Marcel); M. van Straten (Marcel)

    2017-01-01

    textabstractObjectives: The purpose of this study was to assess the efficacy of the renewed dynamic collimator in a third-generation dual source CT (DSCT) scanner and to determine the improvements over the second-generation scanner. Methods: Collimator efficacy is defined as the percentage overrangi

  1. Dose heterogeneity correction for low-energy brachytherapy sources using dual-energy CT images.

    Science.gov (United States)

    Mashouf, S; Lechtman, E; Lai, P; Keller, B M; Karotki, A; Beachey, D J; Pignol, J P

    2014-09-21

    Permanent seed implant brachytherapy is currently used for adjuvant radiotherapy of early stage prostate and breast cancer patients. The current standard for calculation of dose around brachytherapy sources is based on the AAPM TG-43 formalism, which generates the dose in a homogeneous water medium. Recently, AAPM TG-186 emphasized the importance of accounting for tissue heterogeneities. We have previously reported on a methodology where the absorbed dose in tissue can be obtained by multiplying the dose, calculated by the TG-43 formalism, by an inhomogeneity correction factor (ICF). In this work we make use of dual energy CT (DECT) images to extract ICF parameters. The advantage of DECT over conventional CT is that it eliminates the need for tissue segmentation as well as assignment of population based atomic compositions. DECT images of a heterogeneous phantom were acquired and the dose was calculated using both TG-43 and TG-43 [Formula: see text] formalisms. The results were compared to experimental measurements using Gafchromic films in the mid-plane of the phantom. For a seed implant configuration of 8 seeds spaced 1.5 cm apart in a cubic structure, the gamma passing score for 2%/2 mm criteria improved from 40.8% to 90.5% when ICF was applied to TG-43 dose distributions.

  2. Assessment of thoracic aortic elasticity: a preliminary study using electrocardiographically gated dual-source CT

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ning; Guo, Lijun; Sun, Haitao; Gao, Fei; Liu, Cheng [Shandong University, Shandong Medical Imaging Research Institute, Jinan (China); Beck, Thomas [Siemens AG, Healthcare Sector, Imaging and IT Division, Computed Tomography, Forchheim (Germany); Chen, Jiuhong [Siemens Ltd., China, Healthcare, No.7, Wangjing Zhonghuan Nanlu, Beijing (China); Biermann, Christina [Siemens AG, Siemens Healthcare Consulting, Erlangen (Germany)

    2011-07-15

    To gain a new insight into the elastic properties of the thoracic aorta in patients without aortic diseases using electrocardiographically (ECG)-gated dual-source (DS) CT. 56 subjects with no cardiovascular disease, selected from 2,700 people undergoing ECG-gated DSCT examination, were divided into three groups according to their age. CT data were reconstructed in 5% step throughout the RR interval. Diameter and area were measured at the curve of the ascending aorta (AA) and at the same level of the descending aorta (DA). The pulsation and elasticity of the aorta were evaluated. Aortic diameter changes were noted throughout the cardiac cycle. The maximum average diameter was seen at an RR interval of 24.02 {+-} 4.99% for the AA and 25.63 {+-} 4.77% for the DA. The minimum was at 93.5 {+-} 4.04% for the AA and 96.6 {+-} 4.58% for the DA. There was an age-dependent decrease in elasticity, while different correlation coefficients were found between various age groups and different elastic parameters. The properties of aortic pulsation and wall elasticity could be well shown by ECG-gated DSCT. The new findings regarding segment difference and age relevance were significant and should be taken into account in clinical trials and treatments for the elasticity related cardiovascular diseases. (orig.)

  3. Dose heterogeneity correction for low-energy brachytherapy sources using dual-energy CT images

    Science.gov (United States)

    Mashouf, S.; Lechtman, E.; Lai, P.; Keller, B. M.; Karotki, A.; Beachey, D. J.; Pignol, J. P.

    2014-09-01

    Permanent seed implant brachytherapy is currently used for adjuvant radiotherapy of early stage prostate and breast cancer patients. The current standard for calculation of dose around brachytherapy sources is based on the AAPM TG-43 formalism, which generates the dose in a homogeneous water medium. Recently, AAPM TG-186 emphasized the importance of accounting for tissue heterogeneities. We have previously reported on a methodology where the absorbed dose in tissue can be obtained by multiplying the dose, calculated by the TG-43 formalism, by an inhomogeneity correction factor (ICF). In this work we make use of dual energy CT (DECT) images to extract ICF parameters. The advantage of DECT over conventional CT is that it eliminates the need for tissue segmentation as well as assignment of population based atomic compositions. DECT images of a heterogeneous phantom were acquired and the dose was calculated using both TG-43 and TG-43 × \\text{ICF} formalisms. The results were compared to experimental measurements using Gafchromic films in the mid-plane of the phantom. For a seed implant configuration of 8 seeds spaced 1.5 cm apart in a cubic structure, the gamma passing score for 2%/2 mm criteria improved from 40.8% to 90.5% when ICF was applied to TG-43 dose distributions.

  4. Single- and dual-energy CT of the abdomen: comparison of radiation dose and image quality of 2nd and 3rd generation dual-source CT

    Energy Technology Data Exchange (ETDEWEB)

    Wichmann, Julian L. [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Hardie, Andrew D.; Felmly, Lloyd M.; Perry, Jonathan D.; Varga-Szemes, Akos; De Cecco, Carlo N. [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Schoepf, U.J. [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Medical University of South Carolina, Division of Cardiology, Department of Medicine, Charleston, SC (United States); Mangold, Stefanie [University Hospital of Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany); Caruso, Damiano [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); University of Rome ' ' Sapienza' ' , Department of Radiological Sciences, Oncological and Pathological Sciences, Latina (Italy); Canstein, Christian [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Siemens Medical Solutions USA, Malvern, PA (United States); Vogl, Thomas J. [University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany)

    2017-02-15

    To compare single-energy (SECT) and dual-energy (DECT) abdominal CT examinations in matched patient cohorts regarding differences in radiation dose and image quality performed with second- and third-generation dual-source CT (DSCT). We retrospectively analysed 200 patients (100 male, 100 female; mean age 61.2 ± 13.5 years, mean body mass index 27.5 ± 3.8 kg/m{sup 2}) equally divided into four groups matched by gender and body mass index, who had undergone portal venous phase abdominal CT with second-generation (group A, 120-kV-SECT; group B, 80/140-kV-DECT) and third-generation DSCT (group C, 100-kV-SECT; group D, 90/150-kV-DECT). The radiation dose was normalised for 40-cm scan length. Dose-independent figure-of-merit (FOM) contrast-to-noise ratios (CNRs) were calculated for various organs and vessels. Subjective overall image quality and reader confidence were assessed. The effective normalised radiation dose was significantly lower (P < 0.001) in groups C (6.2 ± 2.0 mSv) and D (5.3 ± 1.9 mSv, P = 0.103) compared to groups A (8.8 ± 2.3 mSv) and B (9.7 ± 2.4 mSv, P = 0.102). Dose-independent FOM-CNR peaked for liver, kidney, and portal vein measurements (all P ≤ 0.0285) in group D. Subjective image quality and reader confidence were consistently rated as excellent in all groups (all ≥1.53 out of 5). With both DSCT generations, abdominal DECT can be routinely performed without radiation dose penalty compared to SECT, while third-generation DSCT shows improved dose efficiency. (orig.)

  5. High-pitch dual-source CT angiography of the whole aorta without ECG synchronisation: Initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Beeres, Martin; Schell, Boris; Mastragelopoulos, Aristidis; Kerl, Josef Matthias; Gruber-Rouh, Tatjana; Lee, Clara; Siebenhandl, Petra; Bodelle, Boris; Zangos, Stephan; Vogl, Thomas J.; Jacobi, Volkmar; Bauer, Ralf W. [Clinic of the Goethe University, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Herrmann, Eva [Clinic of the Goethe University, Department of Biostatistics, Frankfurt (Germany)

    2012-01-15

    To investigate the feasibility, image quality and radiation dose for high-pitch dual-source CT angiography (CTA) of the whole aorta without ECG synchronisation. Each group of 40 patients underwent CTA either on a 16-slice (group 1) or dual-source CT device with conventional single-source (group 2) or high-pitch mode with a pitch of 3.0 (group 3). The presence of motion or stair-step artefacts of the thoracic aorta was independently assessed by two readers. Subjective and objective scoring of motion and artefacts were significantly reduced in the high-pitch examination protocol (p < 0.05). The imaging length was not significantly different, but the imaging time was significantly (p < 0.001) shorter in the high-pitch group (12.2 vs. 7.4 vs. 1.7 s for groups 1, 2 and 3). The ascending aorta and the coronary ostia were reliably evaluable in all patients of group 3 without motion artefacts as well. High-pitch dual-source CT angiography of the whole aorta is feasible in unselected patients. As a significant advantage over regular pitch protocols, motion-free imaging of the aorta is possible without ECG synchronisation. Thus, this CT mode bears potential to become a standard CT protocol before trans-catheter aortic valve implantation (TAVI). (orig.)

  6. Dual energy virtual CT colonoscopy with dual source computed tomography. Initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Karcaaltincaba, M.; Karaosmanoglu, D.; Akata, D.; Sentuerk, S.; Oezmen, M. [Dept. of Radiology, Hacettepe Univ. School of Medicine (Turkey); Alibek, S. [Dept. of Radiology, Hacettepe Univ. School of Medicine (Turkey); Radiology Inst., Univ. of Erlangen (Germany)

    2009-09-15

    Purpose: To describe the technique of DE MDCT colonoscopy and to assess its feasibility. Materials and Methods: 8 patients were scanned with DSCT with a DE scan protocol and dose modulation software. Analysis was performed using dedicated DE software. Prone non-contrast images and DE supine images after contrast injection were obtained. Results: DE colonoscopic images were successfully obtained in 7 patients, but the FOV did not cover all colonic segments in 1 patient, thus resulting in a technical success rate was 87.5%. Streak artifacts were present in the pelvic region in 2 patients. Virtual unenhanced images and iodine map images were obtained for all patients. In 1 patient a polypoid non-enhancing structure was noted on the iodine map, and conventional colonoscopy revealed impacted stool. Enhancing rectal cancer in 1 patient was correctly shown on the iodine map. Iodine maps helped to differentiate stool fragments/retained fluid by the absence of enhancement when compared to prone CT images. The major advantage of DE colonoscopy was the lack of misregistration. Conclusion: DE MDCT colonoscopy is technically feasible and may obviate the need for unenhanced prone images. It may be possible to perform noncathartic DECT colonoscopy. The major limitation is the limited FOV of tube B. The dose should be optimized to reduce streak artifacts in the pelvic region. (orig.)

  7. Diagnosis of pulmonary artery embolism. Comparison of single-source CT and 3{sup rd} generation dual-source CT using a dual-energy protocol regarding image quality and radiation dose

    Energy Technology Data Exchange (ETDEWEB)

    Petritsch, Bernhard; Kosmala, Aleksander; Gassenmeier, Tobias; Weng, Andreas Max; Veldhoen, Simon; Kunz, Andreas Steven; Bley, Thorsten Alexander [Univ. Hospital Wuerzburg (Germany). Inst. of Diagnostic and Interventional Radiology

    2017-06-15

    To compare radiation dose, subjective and objective image quality of 3 rd generation dual-source CT (DSCT) and dual-energy CT (DECT) with conventional 64-slice single-source CT (SSCT) for pulmonary CTA. 180 pulmonary CTA studies were performed in three patient cohorts of 60 patients each. Group 1: conventional SSCT 120 kV (ref.); group 2: single-energy DSCT 100 kV (ref.); group 3: DECT 90/Sn150 kV. CTDIvol, DLP, effective radiation dose were reported, and CT attenuation (HU) was measured on three central and peripheral levels. The signal-to-noise-ratio (SNR) and contrast-to-noise-ratio (CNR) were calculated. Two readers assessed subjective image quality according to a five-point scale. Mean CTDIvol and DLP were significantly lower in the dual-energy group compared to the SSCT group (p < 0.001 [CTDIvol]; p < 0.001 [DLP]) and the DSCT group (p = 0.003 [CTDIvol]; p = 0.003 [DLP]), respectively. The effective dose in the DECT group was 2.79 ± 0.95 mSv and significantly smaller than in the SSCT group (4.60 ± 1.68 mSv, p < 0.001) and the DSCT group (4.24 ± 2.69 mSv, p = 0.003). The SNR and CNR were significantly higher in the DSCT group (p < 0.001). Subjective image quality did not differ significantly among the three protocols and was rated good to excellent in 75 % (135/180) of cases with an inter-observer agreement of 80 %. Dual-energy pulmonary CTA protocols of 3 rd generation dual-source scanners allow for significant reduction of radiation dose while providing excellent image quality and potential additional information by means of perfusion maps. Dual-energy CT with 90/Sn150 kV configuration allows for significant dose reduction in pulmonary CTA. Subjective image quality was similar among the three evaluated CT-protocols (64-slice SSCT, single-energy DSCT, 90/Sn150 kV DECT) and was rated good to excellent in 75% of cases. Dual-energy CT provides potential additional information by means of iodine distribution maps.

  8. Intensity distribution and impact of scatter for dual-source CT

    Science.gov (United States)

    Kyriakou, Yiannis; Kalender, Willi A.

    2007-12-01

    Apart from forward scatter, which is given for all CT scanners, dual-source CT (DSCT) is also affected by cross-scatter photons from the second tube-detector system arranged at 90°. We investigated the magnitude and distribution of scatter for DSCT and its impact on image quality. Simulations and measurements of homogeneous and anthropomorphic phantoms were conducted for a DSCT scanner (SOMATOM Definition, Siemens Medical Solutions, Forchheim, Germany) at tube voltages of 80 and 120 kV. The simulations of forward scatter were carried out using combined analytical and Monte Carlo simulation methods for a collimation of 19.2 mm for both tube-detector systems. Measurements of cross scatter were performed by switching one tube off, still reading out the corresponding detector. The relative scatter fractions and the distribution of cross scatter were registered for various imaging conditions. Additionally, a detailed noise analysis with respect to the correction of cross-scatter artifacts is provided to evaluate the performance of correction algorithms. The forward-scatter fraction increased with increasing phantom diameter from 0.02 up to 0.11 for PMMA phantoms of 80 to 400 mm diameter. For cross scatter, the mean intensity was equivalent to forward scatter for small phantoms but was larger for increased phantom size and resulted in severe artifacts in the reconstructed images. The outer dimensions and shape of the object are decisive for the cross-scatter intensity distribution whereas the influence of the degree of inhomogeneity of the respective phantom appears to be negligible. Scatter correction suppressed cross-scatter artifacts but increased noise as a function of the cross-scatter fraction. The magnitude of scatter is not negligible for DSCT systems and dedicated corrections are necessary for the assurance of unimpaired image quality.

  9. Xenon ventilation CT using dual-source and dual-energy technique in children with bronchiolitis obliterans: correlation of xenon and CT density values with pulmonary function test results

    Energy Technology Data Exchange (ETDEWEB)

    Goo, Hyun Woo; Yang, Dong Hyun; Seo, Joon Beom; Chae, Eun Jin; Lee, Jeongjin [University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Songpa-gu, Seoul (Korea); Hong, Soo-Jong; Yu, Jinho; Kim, Byoung-Ju [University of Ulsan College of Medicine, Department of Pediatrics, Asan Medical Center, Seoul (Korea); Krauss, Bernhard [Siemens Medical Solutions AG-Computed Tomography, Forchheim (Germany)

    2010-09-15

    Xenon ventilation CT using dual-source and dual-energy technique is a recently introduced, promising functional lung imaging method. To expand its clinical applications evidence of additional diagnostic value of xenon ventilation CT over conventional chest CT is required. To evaluate the usefulness of xenon ventilation CT using dual-source and dual-energy technique in children with bronchiolitis obliterans (BO). Seventeen children (age 7-18 years; 11 boys) with BO underwent xenon ventilation CT using dual-source and dual-energy technique. Xenon and CT density values were measured in normal and hyperlucent lung regions on CT and were compared between the two regions. Volumes of hyperlucent regions and ventilation defects were calculated with thresholds determined by visual and histogram-based analysis. Indexed volumes of hyperlucent lung regions and ventilation defects were correlated with pulmonary function test results. Effective doses of xenon CT were calculated. Xenon (14.6 {+-} 6.4 HU vs 26.1 {+-} 6.5 HU; P < 0.001) and CT density (-892.8 {+-} 25.4 HU vs -812.3 {+-} 38.7 HU; P < 0.001) values were significantly lower in hyperlucent regions than in normal lung regions. Xenon and CT density values showed significant positive correlation for the entire lung in 16 children ({gamma} = 0.55 {+-} 0.17, P < 0.001 or =0.017) and for hyperlucent regions in 13 children ({gamma} = 0.44 {+-} 0.16, P < 0.001 or =0.001-0.019). Indexed volumes and volume percentages of hyperlucent lung regions and ventilation defects showed strong negative correlations with forced expiratory volume [FEV1, ({gamma} = -0.64-0.85, P {<=} 0.006)], FEV1/forced vital capacity [FVC, ({gamma} = -0.63-0.84, P {<=} 0.008)], and forced midexpiratory flow rate [FEF{sub 25-75}, ({gamma} = -0.68-0.88, P {<=} 0.002). Volume percentages of xenon ventilation defects (35.0 {+-} 16.4%)] were not significantly different from those of hyperlucent lung regions (38.2 {+-} 18.6%). However, mismatches between the

  10. 双源CT临床应用新进展%Dual-source CT clinical application of new progress

    Institute of Scientific and Technical Information of China (English)

    黄远彬

    2014-01-01

    双源CT进行2种不同能量的X线同步扫描,可获得双能量图像,具有成像速度快,辐射剂量低,图像质量高的优点。双源CT进行冠状动脉成像,图像质量不再受患者心率过快、不规则以及屏气困难的影响,能获得可靠的冠状动脉图像,是目前无创性左室功能检查评价最具价值的检查方法之一。双源CT扫描时间缩短辐射剂量降低,有效克服部分患者移动伪影及呼吸伪影,适用于儿童患者及躁动患者的检查,为急性胸痛患者快速诊断提供安全有效手段。双源CT双能量虚拟平扫在头部、胸部、腹部疾病检查中已得到良好运用。双源CT在两种不同能量状态下的数据采集可对物质成分进行定性分析,拓宽了CT的应用范围,具有较好临床价值。%Dual source CT for 2 different energy X-ray scanning, can obtain the dual energy images, has fast imaging speed, low radiation dose, the advantages of high image quality. Dual source CT coronary artery imaging, image quality is not affected by the patient’s heart rate too fast, irregular and breath dififcult, can obtain the coronary artery image reliable;it is one of the current inspection method without evaluation and examination of the left ventricular function most value. Dual source CT scan can reduce the time of radiation dose, effectively overcome some patients moving artifact and respiratory artifacts, suitable for children patients and agitation of patients, to provide safe, effective method for the rapid diagnosis and emergency classiifcation of patients with acute chest pain. Dual energy CT virtual scan has been well used in the head, chest, abdominal disease examination. Dual source CT for qualitative analysis of components in two different energy state of the data acquisition, and widen the application range of CT, with good clinical application.

  11. Efficacy of a dynamic collimator for overranging dose reduction in a second- and third-generation dual source CT scanner

    OpenAIRE

    Booij, Ronald; Dijkshoorn, Marcel; Straten, Marcel

    2017-01-01

    textabstractObjectives: The purpose of this study was to assess the efficacy of the renewed dynamic collimator in a third-generation dual source CT (DSCT) scanner and to determine the improvements over the second-generation scanner. Methods: Collimator efficacy is defined as the percentage overranging dose in terms of dose–length product (DLP) that is blocked by the dynamic collimator relative to the total overranging dose in case of a static collimator. Efficacy was assessed at various pitch...

  12. Diagnostic accuracy of dual-source CT coronary angiography in patients with atrial fibrillation: Meta analysis

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Gang, E-mail: cjr.sungang@vip.163.com [Department of Medical Imaging, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Li, Min [Department of Medical Imaging, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Jiang, Zhi-wei [Department of Health Statistics, School of Public Health, Fourth Military Medical University, No. 169, Changle West Road, Xi’an, Shaanxi 710032 (China); Xu, Lin [Department of Medical Cardiology, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Peng, Zhao-hui; Ding, Juan; Li, Li [Department of Medical Imaging, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Jin, Zhi-tao [Department of Cardiology, General Hospital of the Second Artillery, Beijing 100088 (China)

    2013-10-01

    Rationale and objective: To synthesize the available data to underscore the diagnostic accuracy of dual-source CT (DSCT) coronary angiography in patients with atrial fibrillation (AF). Materials and methods: We searched in the electronic databases of PubMed for all published studies that examined patients with AF using DSCT. We used an exact binomial rendition of the bivariate mixed-effects regression model to synthesize the diagnostic data. Results: The positive and negative likelihood ratios (LRs) at the patient level were 6.0 (CI, 3.6–10.1) and 0.03(CI, 0.004–0.2), respectively. The negative predictive values higher than 90% were available for a CAD prevalence <78%. The pooled vessel- and segment-level estimates showed higher positive and negative LRs than the patient-level estimates (15.3 [CI, 9.8–23.9] and 0.1 [CI, 0.07–0.3]; 25.1 [CI, 10.8–58.5] and 0.2 [CI, 0.2–0.3], respectively). No statistically significant heterogeneity between studies and publication bias were found at the patient level estimate. A sensitivity analysis showed that no study influenced the pooled results larger than 0.02. Conclusions: Cardiac angiography with DSCT can be applied as an imaging test for ruling out CAD in patient with AF. However, DSCT angiography may be not an effective tool for risk stratification for the high negative LR at the artery and segment levels.

  13. Dual-step prospective ECG-triggered 128-slice dual-source CT for evaluation of coronary arteries and cardiac function without heart rate control: a technical note

    Energy Technology Data Exchange (ETDEWEB)

    Feuchtner, Gudrun [University Hospital Zurich, Institute of Diagnostic Radiology, Zurich (Switzerland); Innsbruck Medical University, Department of Radiology II, Innsbruck (Austria); Goetti, Robert; Marincek, Borut; Alkadhi, Hatem; Leschka, Sebastian [University Hospital Zurich, Institute of Diagnostic Radiology, Zurich (Switzerland); Plass, Andre; Wieser, Monika [University Hospital Zurich, Clinic for Cardiovascular Surgery, Zurich (Switzerland); Baumueller, Stephan; Stolzmann, Paul; Scheffel, Hans [University Hospital Zurich, Institute of Diagnostic Radiology, Zurich (Switzerland); University Hospital Zurich, Clinic for Cardiovascular Surgery, Zurich (Switzerland)

    2010-09-15

    To describe prospective ECG-triggered dual-source CT dual-step pulsing (pECG{sub dual-step}) for evaluation of coronary arteries and cardiac function. Fifty-one consecutive patients pre- or post-cardiovascular surgery were examined with adaptive sequential tube current modulated (pECG{sub dual-step}) 128-slice dual-source CT without heart rate control (main padding window: 40% RR interval >65 bpm/70% RR interval <65 bpm). Image quality of coronary arteries was graded (4-point scale), and cardiac function was evaluated. Mean HR was 68 bpm. Thirty-seven patients were in stable sinus rhythm (SR); 14 had arrhythmia. Image quality of coronary arteries was diagnostic in 804/816 (98%) of segments. The number of non-diagnostic segments was higher in patients with arrhythmia as compared to those in SR (4% vs. 0.5%; p = 0.01), and there were fewer segments with excellent image quality (79% vs. 94%; p < 0.001) and more segments with impaired image quality (p < 0.001 and p = 0.002). Global and regional LV function could be evaluated in 41 (80%) and 47 (92%) patients, and valvular function in 48 (94%). In 11/14 of patients with arrhythmia, the second step switched to full mAs, increasing radiation exposure to 8.6 mAs (p < 0.001). The average radiation dose was 3.8 mSv (range, 1.7-7.9) in patients in SR. pECG{sub dual-step}128-slice DSCT is feasible for the evaluation of coronary arteries and cardiac function without heart rate control in patients in stable sinus rhythm at a low radiation dose. (orig.)

  14. Diagnostic accuracy of 128-slice dual-source CT coronary angiography: a randomized comparison of different acquisition protocols

    Energy Technology Data Exchange (ETDEWEB)

    Neefjes, Lisan A.; Kate, Gert-Jan R. ten [Erasmus Medical Center, Department of Cardiology, Room Hs 207, P.O. Box 2040, Rotterdam (Netherlands); Erasmus Medical Center, Department of Radiology, Rotterdam (Netherlands); Interuniversity Cardiology Institute of the Netherlands, Utrecht (Netherlands); Rossi, Alexia; Nieman, Koen; Papadopoulou, Stella L.; Dharampal, Anoeshka S.; Dedic, Admir; Feyter, Pim J. de; Mollet, Nico R. [Erasmus Medical Center, Department of Cardiology, Room Hs 207, P.O. Box 2040, Rotterdam (Netherlands); Erasmus Medical Center, Department of Radiology, Rotterdam (Netherlands); Genders, Tessa S.S.; Hunink, M.G.M. [Erasmus Medical Center, Department of Radiology, Rotterdam (Netherlands); Erasmus Medical Center, Department of Epidemiology, Rotterdam (Netherlands); Schultz, Carl J. [Erasmus Medical Center, Department of Cardiology, Room Hs 207, P.O. Box 2040, Rotterdam (Netherlands); Weustink, Annick C.; Dijkshoorn, Marcel L.; Straten, Marcel van; Cademartiri, Filippo; Krestin, Gabriel P. [Erasmus Medical Center, Department of Radiology, Rotterdam (Netherlands)

    2013-03-15

    To compare the diagnostic performance and radiation exposure of 128-slice dual-source CT coronary angiography (CTCA) protocols to detect coronary stenosis with more than 50 % lumen obstruction. We prospectively included 459 symptomatic patients referred for CTCA. Patients were randomized between high-pitch spiral vs. narrow-window sequential CTCA protocols (heart rate below 65 bpm, group A), or between wide-window sequential vs. retrospective spiral protocols (heart rate above 65 bpm, group B). Diagnostic performance of CTCA was compared with quantitative coronary angiography in 267 patients. In group A (231 patients, 146 men, mean heart rate 58 {+-} 7 bpm), high-pitch spiral CTCA yielded a lower per-segment sensitivity compared to sequential CTCA (89 % vs. 97 %, P = 0.01). Specificity, PPV and NPV were comparable (95 %, 62 %, 99 % vs. 96 %, 73 %, 100 %, P > 0.05) but radiation dose was lower (1.16 {+-} 0.60 vs. 3.82 {+-} 1.65 mSv, P < 0.001). In group B (228 patients, 132 men, mean heart rate 75 {+-} 11 bpm), per-segment sensitivity, specificity, PPV and NPV were comparable (94 %, 95 %, 67 %, 99 % vs. 92 %, 95 %, 66 %, 99 %, P > 0.05). Radiation dose of sequential CTCA was lower compared to retrospective CTCA (6.12 {+-} 2.58 vs. 8.13 {+-} 4.52 mSv, P < 0.001). Diagnostic performance was comparable in both groups. Sequential CTCA should be used in patients with regular heart rates using 128-slice dual-source CT, providing optimal diagnostic accuracy with as low as reasonably achievable (ALARA) radiation dose. circle 128-slice dual-source CT coronary angiography offers several different acquisition protocols. (orig.)

  15. Virtual monochromatic imaging in dual-source and dual-energy CT for visualization of acute ischemic stroke

    CERN Document Server

    Hara, Hidetake; Matsuzawa, Hiroki; Inoue, Toshiyuki; Abe, Shinji; Satoh, Hitoshi; Nakajima, Yasuo

    2015-01-01

    We have recently developed a phantom that simulates acute ischemic stroke. We attempted to visualize acute-stage cerebral infarction by applying virtual monochromatic images to this phantom using dual-energy CT (DECT). Virtual monochromatic images were created using DECT from 40 to 100 keV at every 10 keV and from 60 to 80 keV at every 1 keV, under three energy conditions of tube voltages with thin (Sn) filters. Calculation of the CNR values allowed us to evaluate the visualization of acute-stage cerebral infarction. The CNR value of a virtual monochromatic image was the highest at 68 keV under 80 kV / Sn 140 kV, at 72 keV under 100 kV / Sn 140 kV, and at 67 keV under 140 kV / 80 kV. The CNR values of virtual monochromatic images between 65 and 75 keV were significantly higher than those obtained for all other created energy images. Therefore, optimal conditions for visualizing acute ischemic stroke were achievable.

  16. Dual source multidetector CT-angiography before transcatheter aortic valve implantation (TAVI) using a high-pitch spiral acquisition mode

    Energy Technology Data Exchange (ETDEWEB)

    Wuest, W.; Anders, K.; May, M.S.; Uder, M. [University of Erlangen, Department of Radiology, Erlangen (Germany); Schuhbaeck, A.; Gauss, S.; Marwan, M.; Arnold, M.; Muschiol, G.; Daniel, W.G.; Achenbach, S. [University of Erlangen, Department of Cardiology, Erlangen (Germany); Ensminger, S. [University of Erlangen, Department of Cardiac Surgery, Erlangen (Germany)

    2012-01-15

    Transcatheter Aortic Valve Implantation (TAVI) is an alternative to surgical valve replacement in high risk patients. Angiography of the aortic root, aorta and iliac arteries is required to select suitable candidates, but contrast agents can be harmful due to impaired renal function. We evaluated ECG-triggered high-pitch spiral dual source Computed Tomography (CT) with minimized volume of contrast agent to assess aortic root anatomy and vascular access. 42 patients (82 {+-} 6 years) scheduled for TAVI underwent dual source (DS) CT angiography (CTA) of the aorta using a prospectively ECG-triggered high-pitch spiral mode (pitch = 3.4) with 40 mL iodinated contrast agent. We analyzed aortic root/iliac dimensions, attenuation, contrast to noise ratio (CNR), image noise and radiation exposure. Aortic root/iliac dimensions and distance of coronary ostia from the annulus could be determined in all cases. Mean aortic and iliac artery attenuation was 320 {+-} 70 HU and 340 {+-} 77 HU. Aortic/iliac CNR was 21.7 {+-} 6.8 HU and 14.5 {+-} 5.4 HU using 100 kV (18.8 {+-} 4.1 HU and 8.7 {+-} 2.6 HU using 120 kV). Mean effective dose was 4.5 {+-} 1.2 mSv. High-pitch spiral DSCTA can be used to assess the entire aorta and iliac arteries in TAVI candidates with a low volume of contrast agent while preserving diagnostic image quality. (orig.)

  17. Dual-source dual-energy CT angiography with virtual non-enhanced images and iodine map for active gastrointestinal bleeding: Image quality, radiation dose and diagnostic performance

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Hao, E-mail: sunhao_robert@126.com [Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Shuaifuyuan No. 1, Wangfujing Street, Dongcheng District, Beijing 100730 (China); Hou, Xin-Yi, E-mail: hxy_pumc@126.com [Department of Radiology, Beijing Tiantan Hospital, Capital Medical University, Beijing (China); Xue, Hua-Dan, E-mail: bjdanna95@hotmail.com [Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Shuaifuyuan No. 1, Wangfujing Street, Dongcheng District, Beijing 100730 (China); Li, Xiao-Guang, E-mail: xglee88@126.com [Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Shuaifuyuan No. 1, Wangfujing Street, Dongcheng District, Beijing 100730 (China); Jin, Zheng-Yu, E-mail: zhengyu_jin@126.com [Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Shuaifuyuan No. 1, Wangfujing Street, Dongcheng District, Beijing 100730 (China); Qian, Jia-Ming, E-mail: qjiaming57@gmail.com [Department of Gastroenterology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing (China); Yu, Jian-Chun, E-mail: yu-jch@163.com [Department of General Surgery, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing (China); Zhu, Hua-Dong, E-mail: huadongzhu@hotmail.com [Department of Emergency, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing (China)

    2015-05-15

    Highlights: • GIB is a common gastrointestinal emergency with a high mortality rate. • Detection and localization of GIB source are important for imaging modality. • DSDECTA using a dual-phase scan protocol is clinically feasible. • DSDECTA with VNE and iodine map images can diagnose the active GIB source accurately. • DSDECTA can reduce radiation dose compared with conventional CT examination in GIB. - Abstract: Objectives: To evaluate the clinical feasibility of dual-source dual-energy CT angiography (DSDECTA) with virtual non-enhanced images and iodine map for active gastrointestinal bleeding (GIB). Methods: From June 2010 to December 2012, 112 consecutive patients with clinical signs of active GIB underwent DSDECTA with true non-enhanced (TNE), arterial phase with single-source mode, and portal-venous phase with dual-energy mode (100 kVp/230 mAs and Sn 140 kVp/178 mAs). Virtual non-enhanced CT (VNE) image sets and iodine map were reformatted from ‘Liver VNC’ software. The mean CT number, noise, signal to noise ratio (SNR), image quality and radiation dose were compared between TNE and VNE image sets. Two radiologists, blinded to clinical data, interpreted images from DSDECTA with TNE (protocol 1), and DSDECTA with VNE and iodine map (protocol 2) respectively, with discordant interpretation resolved by consensus. The standards of reference included digital subtraction angiography, endoscopy, surgery, or final pathology reports. Receiver–operating characteristic (ROC) analysis was undertaken and the area under the curve (AUC) calculated for CT protocols 1 and 2, respectively. Results: There was no significant difference in mean CT numbers of all organs (including liver, pancreas, spleen, kidney, abdominal aorta, and psoas muscle) (P > 0.05). Lower noise and higher SNR were found on VNE images than TNE images (P < 0.05). Image quality of VNE was lower than that of TNE without significant difference (P > 0.05). The active GIB source was identified

  18. Prospectively ECG-triggered sequential dual-source coronary CT angiography in patients with atrial fibrillation: comparison with retrospectively ECG-gated helical CT

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Lei; Yang, Lin; Zhang, Zhaoqi [Capital Medical University, Department of Radiology, Beijing Anzhen Hospital, Beijing (China); Wang, Yining; Jin, Zhengyu [Chinese Academy of Medical Sciences, Department of Radiology, Peking Union Medical College Hospital, Beijing (China); Zhang, Longjiang; Lu, Guangming [Nanjing University, Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing, Jiangsu (China)

    2013-07-15

    To investigate the feasibility of applying prospectively ECG-triggered sequential coronary CT angiography (CCTA) to patients with atrial fibrillation (AF) and evaluate the image quality and radiation dose compared with a retrospectively ECG-gated helical protocol. 100 patients with persistent AF were enrolled. Fifty patients were randomly assigned to a prospective protocol and the other patients to a retrospective protocol using a second-generation dual-source CT (DS-CT). Image quality was evaluated using a four-point grading scale (1 = excellent, 2 = good, 3 = moderate, 4 = poor) by two reviewers on a per-segment basis. The coronary artery segments were considered non-diagnostic with a quality score of 4. The radiation dose was evaluated. Diagnostic segment rate in the prospective group was 99.4 % (642/646 segments), while that in the retrospective group was 96.5 % (604/626 segments) (P < 0.001). Effective dose was 4.29 {+-} 1.86 and 11.95 {+-} 5.34 mSv for each of the two protocols (P < 0.001), which was a 64 % reduction in the radiation dose for prospective sequential imaging compared with retrospective helical imaging. In AF patients, prospectively ECG-triggered sequential CCTA is feasible using second-generation DS-CT and can decrease >60 % radiation exposure compared with retrospectively ECG-gated helical imaging while improving diagnostic image quality. (orig.)

  19. Energy Limits in Second Generation High-pitch Dual Source CT - Comparison in an Upper Abdominal Phantom

    Directory of Open Access Journals (Sweden)

    Martin Beeres

    2015-01-01

    Full Text Available Objectives: The aim of our study was to find out how much energy is applicable in second-generation dual source high-pitch computed tomography (CT in imaging of the abdomen. Materials and Methods: We examined an upper abdominal phantom using a Somatom Definition Flash CT-Scanner (Siemens, Forchheim, Germany. The study protocol consisted of a scan-series at 100 kV and 120 kV. In each scan series we started with a pitch of 3.2 and reduced it in steps of 0.2, until a pitch of 1.6 was reached. The current was adjusted to the maximum the scanner could achieve. Energy values, image noise, image quality, and radiation exposure were evaluated. Results: For a pitch of 3.2 the maximum applicable current was 142 mAs at 120 kV and in 100 kV the maximum applicable current was 114 mAs. For conventional abdominal imaging, current levels of 200 to 260 mAs are generally used. To achieve similar current levels, we had to decrease the pitch to 1.8 at 100 kV - at this pitch we could perform our imaging at 204 mAs. At a pitch of 2.2 in 120 kV we could apply a current of 206 mAs. Conclusion: We conclude our study by stating that if there is a need for a higher current, we have to reduce the pitch. In a high-pitch dual source CT, we always have to remember where our main focus is, so we can adjust the pitch to the energy we need in the area of the body that has to be imaged, to find answers to the clinical question being raised.

  20. Automatic selection of an optimal systolic and diastolic reconstruction windows for dual-source CT coronary angiography

    Science.gov (United States)

    Seifarth, H.; Puesken, M.; Wienbeck, S.; Maintz, D.; Heindel, W.; Juergens, K.-U.

    2008-03-01

    Purpose: To assess the performance of a motion map algorithm to automatically determine the optimal systolic and diastolic reconstruction window for coronary CT Angiography using Dual Source CT. Materials and Methods: Dual Source coronary CT angiography data sets (Somatom Definition, Siemens Medical Solutions) from 50 consecutive patients were included in the analysis. Optimal systolic and diastolic reconstruction windows were determined using a motion map algorithm (BestPhase, Siemens Medical Solutions). Additionally data sets were reconstructed in 5% steps throughout the RR-interval. For each major vessel (RCA, LAD and LCX) an optimal systolic and diastolic reconstruction window was manually determined by two independent readers using volume rendering displays. Image quality was rated using a five-point scale (1 = no motion artifacts, 5 = severe motion artifacts over entire length of the vessel). Results: The mean heart rate during the scan was 72.4bpm (+/-15.8bpm). Median systolic and diastolic reconstruction windows using the BestPhase algorithm were at 37% and 73% RR. The median manually selected systolic reconstruction window was 35 %, 30% and 35% for RCA, LAD, and LCX. For all vessels the median observer selected diastolic reconstruction window was 75%. Mean image quality using the BestPhase algorithm was 2.4 +/-0.9 for systolic reconstructions and 1.9 +/-1.1 for diastolic reconstructions. Using the manual approach, the mean image quality was 1.9 +/-0.5 and 1.7 +/-0.8 respectively. There was a significant difference in image quality between automatically and manually determined systolic reconstructions (p<0.01) but there was no significant difference in image quality in diastolic reconstructions. Conclusion: Automatic determination of the optimal reconstruction interval using the BestPhase algorithm is feasible and yields reconstruction windows similar to observer selected reconstruction windows. In diastolic reconstructions overall image quality is similar

  1. High-pitch dual-source CT coronary angiography with low volumes of contrast medium

    Energy Technology Data Exchange (ETDEWEB)

    Lembcke, Alexander; Hein, Patrick A.; Knobloch, Gesine; Durmus, Tahir; Hamm, Bernd [Charite - University Medicine Berlin, Department of Radiology, Berlin (Germany); Schwenke, Carsten [SCO:SSiS - Schwenke Consulting, Berlin (Germany); Huppertz, Alexander [Charite - University Medicine Berlin, Department of Radiology, Berlin (Germany); ISI - Imaging Science Institute Charite, Berlin (Germany)

    2014-01-15

    To assess the effect of lower volumes of contrast medium (CM) on image quality in high-pitch dual-source computed tomography coronary angiography (CTCA). One-hundred consecutive patients (body weight 65-85 kg, stable heart rate ≤65 bpm, cardiac index ≥2.5 L/min/m{sup 2}) referred for CTCA were prospectively enrolled. Patients were randomly assigned to one of five groups of different CM volumes (G{sub 30}, 30 mL; G{sub 40}, 40 mL; G{sub 50}, 50 mL; G{sub 60}, 60 mL; G{sub 70}, 70 mL; flow rate 5 mL/s each, iodine content 370 mg/mL). Attenuation within the proximal and distal coronary artery segments was analysed. Mean attenuation for men and women ranged from 345.0 and 399.1 HU in G{sub 30} to 478.2 and 571.8 HU in G{sub 70}. Mean attenuation values were higher in groups with higher CM volumes (P < 0.0001) and higher in women than in men (P < 0.0001). The proportions of segments with attenuation of at least 300 HU in G{sub 30}, G{sub 40}, G{sub 50}, G{sub 60} and G{sub 70} were 89 %, 95 %, 98 %, 98 % and 99 %. CM volume of 30 mL in women and 40 mL in men proved to be sufficient to guarantee attenuation of at least 300 HU. In selected patients high-pitch dual-source CTCA can be performed with CM volumes of 40 mL in men or 30 mL in women. (orig.)

  2. High-pitch coronary CT angiography in dual-source CT during free breathing vs. breath holding in patients with low heart rates

    Energy Technology Data Exchange (ETDEWEB)

    Bischoff, Bernhard, E-mail: bernhard.bischoff@med.uni-muenchen.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich (Germany); DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich (Germany); Meinel, Felix G. [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich (Germany); DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich (Germany); Del Prete, Alessandra [Department of Radiology Magrassi-Lanzara, Second University of Naples, Naples (Italy); Reiser, Maximilian F.; Becker, Hans-Christoph [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich (Germany); DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich (Germany)

    2013-12-01

    Background: Coronary CT angiography (CCTA) is usually performed during breath holding to reduce motion artifacts caused by respiration. However, some patients are not able to follow the breathing commands adequately due to deafness, hearing impairment, agitation or pulmonary diseases. The aim of this study was to evaluate the potential of high-pitch CCTA in free breathing patients when compared to breath holding patients. Methods: In this study we evaluated 40 patients (20 free breathing and 20 breath holding patients) with a heart rate of 60 bpm or below referred for CCTA who were examined on a 2nd generation dual-source CT system. Image quality of each coronary artery segment was rated using a 4-point grading scale (1: non diagnostic–4: excellent). Results: Mean heart rate during image acquisition was 52 ±5 bpm in both groups. There was no significant difference in mean image quality, slightly favoring image acquisition during breath holding (mean image quality score 3.76 ± 0.32 in breath holding patients vs. 3.61 ± 0.45 in free breathing patients; p = 0.411). Due to a smaller amount of injected contrast medium, there was a trend for signal intensity to be slightly lower in free breathing patients, but this was not statistically significant (435 ± 123 HU vs. 473 ± 117 HU; p = 0.648). Conclusion: In patients with a low heart rate who are not able to hold their breath adequately, CCTA can also be acquired during free breathing without substantial loss of image quality when using a high pitch scan mode in 2nd generation dual-source CT.

  3. Automated attenuation-based tube voltage selection for body CTA: Performance evaluation of 192-slice dual-source CT

    Energy Technology Data Exchange (ETDEWEB)

    Winklehner, Anna; Gordic, Sonja; Lauk, Eliane; Frauenfelder, Thomas; Alkadhi, Hatem; Husarik, Daniela B. [University Hospital Zurich, Institute for Diagnostic and Interventional Radiology, Zurich (Switzerland); Leschka, Sebastian [University Hospital Zurich, Institute for Diagnostic and Interventional Radiology, Zurich (Switzerland); Division of Radiology and Nuclear Medicine, St. Gallen (Switzerland)

    2015-08-15

    To assess radiation dose and image quality in body CT-angiography (CTA) with automated attenuation-based tube voltage selection (ATVS) on a 192-slice dual-source CT (DSCT). Forty patients (69.5 ± 9.6 years) who had undergone body CTA with ATVS (ref.kVp 100, ref.mAs 90) using a 2x192-slice CT in single-source mode were retrospectively included. All patients had undergone prior CTA with a 2x128-slice CT and ATVS with identical imaging and contrast media protocols, serving for comparison. Images were reconstructed with iterative reconstruction at similar strength levels. Radiation dose was determined. Image quality was assessed semi-quantitatively (1:excellent, 5:non-diagnostic), aortic attenuation, noise and CNR were determined. As compared to 128-slice DSCT, 192-slice DSCT selected tube voltages were lower in 30 patients (75 %), higher in 3 (7.5 %), and similar in 7 patients (17.5 %). CTDI{sub vol} was lower with 192-slice DSCT (4.7 ± 1.9 mGy vs. 5.8 ± 2.1 mGy; p < 0.001). Subjective image quality, mean aortic attenuation (342 ± 67HU vs. 268 ± 67HU) and CNR (9.8 ± 2.5 vs. 8.2 ± 2.9) were higher with 192-slice DSCT (all p < 0.01), all datasets being diagnostic. Our study suggests that ATVS of 192-slice DSCT for body CTA is associated with an improved image quality and further radiation dose reduction of 19 % compared to 128-slice DSCT. (orig.)

  4. Electrocardiographically triggered CT angiography of the whole aorta and coronary arteries with high-pitch dual-source CT

    Institute of Scientific and Technical Information of China (English)

    张楠

    2013-01-01

    Objective To investigate the feasibility of comprehensive assessment of the whole aorta and coronary arteries(CA)simultaneously with high-pitch128-slice dualsource CT ECG-gated FLASH protocol.Methods A totalof 48 consecutive patients with suspected aortic diseases

  5. Quantitative assessment of pure aortic valve regurgitation with dual-source CT

    Energy Technology Data Exchange (ETDEWEB)

    Li, Z., E-mail: lzlcd01@126.com [Department of Radiology, West China Hospital, Sichuan University, 37 Guo Xue Xiang, Chengdu, Sichuan 610041 (China); Huang, L.; Chen, X.; Xia, C.; Yuan, Y.; Shuai, T. [Department of Radiology, West China Hospital, Sichuan University, 37 Guo Xue Xiang, Chengdu, Sichuan 610041 (China)

    2012-07-15

    Aim: To assess the severity of pure aortic regurgitation by measuring regurgitation volumes (RV) and fractions (RF) with dual-source computed tomography (DSCT) as compared to magnetic resonance imaging (MRI) and echocardiography. Materials and methods: Thirty-eight patients (15 men, 23 women; mean age 46 {+-} 11 years) with isolated aortic valve regurgitation underwent retrospectively electrocardiogram (ECG)-gated DSCT, echocardiography, and MRI. Stroke volumes of the left and right ventricles were measured at DSCT and MRI. Thus, RVs and RFs were calculated and compared. The agreement between DSCT and MRI was tested by intraclass correlation coefficient and Bland-Altman analyses. Spearman's rank order correlation and weighted {kappa} tests were used for testing correlations of AR severity between DSCT results and corresponding echocardiographic grades. Results: The RV and RF measured by DSCT were not significantly different from those measured using MRI (p = 0.71 and 0.79). DSCT correlated well with MRI for the measurement of RV (r{sub I} = 0.86, p<0.001) and calculation of the RF (r{sub I} =0.90, p<0.001). Good agreement between the techniques was obtained by using Bland-Altman analyses. The severity of regurgitation estimated by echocardiography correlated well with DSCT (r{sub s} = 0.95, p<0.001) and MRI (r{sub s} = 0.95, p<0.001). Inter-technique agreement between DSCT and two-dimensional transthoracic echocardiography (2DTTE) regarding the grading of the severity of AR was excellent ({kappa} = 0.90), and good agreement was also obtained between MRI and 2DTTE assessments of the severity of AR ({kappa} = 0.87). Conclusion: DSCT using a volume approach can be used to quantitatively determine the severity of pure aortic regurgitation when compared with MRI and echocardiography.

  6. Assessment of image quality of 64-row Dual Source versus Single Source CT coronary angiography on heart rate: A phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Dikkers, R. [Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, P.O. Box 30001, 9700 RB Groningen (Netherlands)], E-mail: r.dikkers@rad.umcg.nl; Greuter, M.J.W. [Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, P.O. Box 30001, 9700 RB Groningen (Netherlands)], E-mail: m.j.w.greuter@rad.umcg.nl; Kristanto, W. [Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, P.O. Box 30001, 9700 RB Groningen (Netherlands)], E-mail: w.kristanto@rad.umcg.nl; Ooijen, P.M.A. van [Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, P.O. Box 30001, 9700 RB Groningen (Netherlands)], E-mail: p.m.a.van.ooyen@rad.umcg.nl; Sijens, P.E. [Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, P.O. Box 30001, 9700 RB Groningen (Netherlands)], E-mail: p.e.sijens@rad.umcg.nl; Willems, T.P. [Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, P.O. Box 30001, 9700 RB Groningen (Netherlands)], E-mail: t.p.willems@rad.umcg.nl; Oudkerk, M. [Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, P.O. Box 30001, 9700 RB Groningen (Netherlands)], E-mail: m.oudkerk@rad.umcg.nl

    2009-04-15

    Purpose: To assess the influence of temporal resolution on image quality of computed tomographic (CT) coronary angiography by comparing 64-row Dual Source CT (DSCT) and Single Source CT (SSCT) at different heart rates. Methods: An anthropomorphic moving heart phantom was scanned at rest, and at 50 beats per minute (bpm) up to 110 bpm, with intervals of 10 bpm. 3D volume rendered images and curved multi-planar reconstructions (MPRs) were acquired and image quality of the coronary arteries was rated on a 5-points scale (1 = poor image quality with many artefacts, 5 = excellent image quality) for each heart rate and each scanner by 3 observers. Paired sample t-test and Wilcoxon Signed Ranks test were used to assess clinically relevant differences between both modalities. Results: The mean image quality scores at 70, 100 and 110 bpm were significantly higher for DSCT compared to SSCT. The overall mean image quality scores for DSCT (4.2 {+-} 0.6) and SSCT (3.0 {+-} 1.1) also differed significantly (p < 0.001). Conclusion: These initial results show a clinically relevant overall higher image quality for DSCT compared to SSCT, especially at heart rates of 70, 100 and 110 bpm. With its comparatively high image quality and low radiation dose, DSCT appears to be the method of choice in CT coronary angiography at heart rates above 70 bpm.

  7. Diagnostic accuracy of dual-source CT coronary angiography with prospective ECG-triggering on different heart rate patients

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Ming-li; Lu, Bin; Han, Lei; Liu, Gang; Yu, Fang-Fang; Hou, Zhi-hui; Gao, Yang; Wang, Hong-yu; Jiang, Shiliang [Peking Union Medical College, Department of Radiology, Cardiovascular Institute and Fu Wai Hospital, Chinese Academy of Medical Sciences, Beijing (China); Wu, Run-ze; Johnson, Laura [CT Research Collaboration, Siemens Healthcare, Shang Hai (China); Yang, Yue-jin; Qiao, Shu-bin [Chinese Academy of Medical Sciences, Peking Union Medical College, Department of Cardiology, Division of Coronary Heart Disease, Cardiovascular Institute and Fu Wai Hospital, Beijing (China)

    2011-08-15

    To evaluate the diagnostic accuracy of dual-source CT (DSCT) prospective ECG-triggering coronary angiography in patients with different heart rate (HR). 103 patients with suspected coronary artery disease underwent DSCT prospective ECG-triggered coronary angiography and invasive coronary angiography (ICA). The patients were grouped by HR during CT scans: low HR ({<=}60 bpm, n = 34); medium HR (60 < HR {<=} 70 bpm, n = 36) and high HR (>70 bpm, n = 33). The sensitivity and specificity of DSCT in detecting {>=}50% stenosis were compared among subgroups where ICA was the gold standard. Image quality was scored using a 4-point scale. A total of 1,580 (95.9%) coronary artery segments were evaluable. Sensitivity and specificity were 82.8% and 98.4%, 88.3% and 98.7%, and 80.3% and 98.6% for different subgroups (all p > 0.05). The overall area under the curve of the receiver-operating characteristic analysis was 0.94. The image quality scores were 3.1 {+-} 0.3, 3.1 {+-} 0.3 and 3.0 {+-} 0.4 for subgroups (p > 0.05). The overall average effective radiation dose was 3.60 {+-} 1.60 mSv. DSCT coronary angiography with prospective ECG-triggering could be just as accurate in patients with medium to high HR compared to those with low HR. (orig.)

  8. Dual energy CT

    DEFF Research Database (Denmark)

    Al-Najami, Issam; Drue, Henrik Christian; Steele, Robert

    2017-01-01

    and inaccurate with existing methods. Dual Energy Computed Tomography (DECT) enables qualitative tissue differentiation by simultaneous scanning with different levels of energy. We aimed to assess the feasibility of DECT in quantifying tumor response to neoadjuvant therapy in loco-advanced rectal cancer. METHODS...... to determine the average quantitative parameters; effective-Z, water- and iodine-concentration, Dual Energy Index (DEI), and Dual Energy Ratio (DER). These parameters were compared to the regression in the resection specimen as measured by the pathologist. RESULTS: Changes in the quantitative parameters...

  9. Application of fusion of coincidence PET/CT image and dual source CT image in diagnosis of tumors%经济型PET/CT与双源CT异机融合在肿瘤诊断中的应用

    Institute of Scientific and Technical Information of China (English)

    苏雪娟; 鲍红梅; 刘帆; 李运奇; 高琼

    2012-01-01

    Objective To explore the value of fusion of coincidence PET/CT image and dual source CT image in comparison of fused imaging quality. Methods Integration of coincidence PET/CT PET images with dual source CT images was performed in 29 cases with suspected tumor or tumor recurrence or metastasis, and the image quality was compared with that of PET/CT in fused images. Results Forty-six primary or metastic tumors were detected by both methods. The image quality in fused imaging of stand-alone coincidence PET/CT with dual source CT was better than that of coincidence PET/CT in fused images (X2 = 14. 743, P<0. 001). Conclusion The integration of stand-alone coincidence PET/CT and dual source CT is convenient and practical,having complementary advantages, which may improve image quality and help clinical diagnosis and treatment of tumors.%目的 通过对比分析经济型PET/CT与双源CT异机融合的图像质量,探讨异机融合的临床应用价值.方法 对29例可疑肿瘤或肿瘤复发转移患者行经济型PET/CT的PET与双源CT图像融合,并与同机融合图像质量进行对比分析.结果 两种方法均检出原发灶和转移灶共46个,异机融合图像质量优于同机融合(x2=14.743,P<0.001).结论 双源CT与经济型PET/CT异机融合,方便实用,优势互补,可提高图像质量,对临床诊断和治疗肿瘤有重要价值.

  10. 双源 CT 双能量技术在泌尿系结石诊断中的应用价值%Application value of dual energy technique of dual source CT in the diagnosis of urinary calculi

    Institute of Scientific and Technical Information of China (English)

    高江晖; 马洪宇; 郭文伟; 于庆康

    2016-01-01

    目的:探讨双源 CT 双能量技术在尿路结石组成分析中的预测价值。方法对30例泌尿系统结石患者行双源 CT 双能量扫描,对结石组成成份进行分析,将结果与红外光谱法分析的结石组成相比,计算双源 CT 分析尿酸盐结石、非尿酸盐结石的特异度与灵敏度,判断预测结石的准确性。结果30例泌尿系结石中尿酸盐类结石10例,非尿酸盐类结石20例,尿酸盐结石、非尿酸盐结石在140 kV 能量下 CT 值分别为(312.5±55.5)HU、(650.6±255.5)HU,在100 kV 能量下 CT 值分别为(328.5±50.5)HU、(960.8±180.5)HU,尿酸盐结石、非尿酸盐结石在两种能量下的差值分别为(16.5±5.1)HU、(310.2±26.7)HU,比值分别为(1.05±0.01)HU、(1.47±0.02) HU,尿酸盐结石差值、比值明显低于非尿酸盐结石(P <0.05),双源 CT 可切确辨别尿酸盐类结石与非尿酸盐类结石,其灵敏度、特异度分别为90%、95%。结论双源 CT 双能量成像技术能在尿路结石治疗前对其组成进行分析,对认识结石的成因及预防结石形成有很大帮助。%Objective To investigate the clinical value of dual source dual energy CT( DS-DECT)in predict chemical component of urinary calculi. Methods Selected 30 cases with urinary cal-culi underwent dual source Flash CT,analysed the component of the calculi,compared the results and in-frared spectroscopy analysis of calculi composition,calculated the specificity and sensitivity of urate cal-culi,non urate calculus by dual source CT analysis,and judged the forecasting accuracy of the calculi. Results Among the 30 urinary calculi patients,10 cases had uric acid calculi and 20 cases had non-u-ric acid calculi. Uric acid calculi and non-uric acid calculi under 140 kV energy:CT values were (312. 5 ± 55. 5)HU,(650. 6 ± 255. 5)HU;under 100 kV energy:CT values were(328. 5 ± 50. 5) HU,(960. 8 ± 180. 5)HU;the difference of acid

  11. Assessment of aortic stenosis after aortic valve replacement. Comparative evaluation of dual-source CT and echocardiography; Quantitative Evaluation der Aortenklappenoeffnungsflaeche mit der Dual-Source-CT und Korrelation mit der 2D-Echokardiografie. Initiale Ergebnisse

    Energy Technology Data Exchange (ETDEWEB)

    Saam, T.; Minaifar, N.; Becker, C.; Reiser, M.; Nikolaou, K. [Ludwig-Maximilians-Univ. Muenchen (Germany). Inst. fuer Klinische Radiologie; Oberhoffer, M.; Rist, C.; Vogt, F.; Reichart, B. [Ludwig-Maximilians-Univ. Muenchen (Germany). Herzchirurgische Klinik und Poliklinik

    2008-06-15

    Purpose: To prospectively evaluate whether planimetric measurements of aortic valve area (AVA) with dual-source computed tomography (DSCT) correlate with measurements obtained by echocardiography and to correlate the amount of calcification of the aortic valve with AVA in a group of patients after aortic valve replacement. Materials and Method: 23 patients underwent dual-source computed tomography (DSCT) of the heart (Somatom Definition, Siemens Medical Solutions, Forchheim, Germany), without heart rate control (heart rate 52-113 beats/minute). All patients had undergone aortic valve replacement (homografts, mean time after surgery: 7{+-}3 years). The AVA of the transplanted aortic valve graft was measured planimetrically by means of DSCT and compared with echocardiography as a standard of reference, to exclude post-surgical restenosis of the valve. Maximum AVA in systole planimetrically measured with CT was compared with calculated AVA values determined with the continuity equation, using transvalvular pressure gradients. The amount of calcification of the aortic valve was quantified and correlated (Spearman's R) with the AVA. To assess intra- and inter-reader reproducibility, the DCST data was re-analyzed by two readers 4 weeks after the initial review. Results: All DSCT datasets were of diagnostic image quality concerning valve depiction. The mean AVA as measured by DSCT was 2.7{+-}0.9 cm{sup 2} compared to 1.8{+-}0.5 cm{sup 2} by echocardiography (p<0.05). The planimetric evaluation of the CT data as compared to results of echocardiography showed a significant correlation of the results (Pearson's correlation coefficient R=0.78, p<0.001). Intra- and inter-reader reproducibility was good with intra-class correlation coefficients of 0.86 and 0.81, respectively (p<0.001). There was a significant negative correlation between the amount of aortic valve calcification and AVA as measured by echocardiography (R=-0.42; p<0.05) and as measured by DSCT (R=-0

  12. Adenosine-stress dynamic myocardial perfusion imaging using 128-slice dual-source CT: optimization of the CT protocol to reduce the radiation dose.

    Science.gov (United States)

    Kim, Sung Mok; Kim, Yoo Na; Choe, Yeon Hyeon

    2013-04-01

    The aim of this study was to compare the radiation dose and image quality of different adenosine-stress dynamic myocardial perfusion CT protocols using a 128-slice dual-source computed tomography (DSCT) scanner. We included 330 consecutive patients with suspected coronary artery disease. Protocols employed the following dynamic scan parameters: protocol I, a 30-s scan with a fixed tube current (FTC, n = 172); protocol II, a 30-s scan using an automatic tube current modulation (ATCM) technique (n = 108); protocol III, a 14-s scan using an ATCM (n = 50). To determine the scan interval for protocol III, we analyzed time-attenuation curves of 26 patients with myocardial perfusion who had been scanned using protocol I or II. The maximum attenuation difference between normal and abnormal myocardium occurred at 18.0 s to 30.3 s after initiation of contrast injection. Myocardial perfusion images of FTC and ATCM were of diagnostic image quality based on visual analysis. The mean radiation dose associated with protocols I, II, and III was 12.1 ± 1.6 mSv, 7.7 ± 2.5 mSv, and 3.8 ± 1.3 mSv, respectively (p < 0.01). Use of a dose-modulation technique and a 14-s scan duration for adenosine-stress CT enables significant dose reduction while maintaining diagnostic image quality.

  13. Impact of an advanced image-based monoenergetic reconstruction algorithm on coronary stent visualization using third generation dual-source dual-energy CT: a phantom study

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    Mangold, Stefanie [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Eberhard-Karls University Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany); Cannao, Paola M. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); University of Milan, Scuola di Specializzazione in Radiodiagnostica, Milan (Italy); Schoepf, U.J. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Medical University of South Carolina, Division of Cardiology, Department of Medicine, Charleston, SC (United States); Wichmann, Julian L. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Canstein, Christian [Siemens Medical Solutions, Malvern, PA (United States); Fuller, Stephen R.; Varga-Szemes, Akos [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Muscogiuri, Giuseppe; De Cecco, Carlo N. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); University of Rome ' ' Sapienza' ' , Department of Radiological Sciences, Oncology and Pathology, Rome (Italy); Nikolaou, Konstantin [Eberhard-Karls University Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany)

    2016-06-15

    To evaluate the impact of an advanced monoenergetic (ME) reconstruction algorithm on CT coronary stent imaging in a phantom model. Three stents with lumen diameters of 2.25, 3.0 and 3.5 mm were examined with a third-generation dual-source dual-energy CT (DECT). Tube potential was set at 90/Sn150 kV for DE and 70, 90 or 120 kV for single-energy (SE) acquisitions and advanced modelled iterative reconstruction was used. Overall, 23 reconstructions were evaluated for each stent including three SE acquisitions and ten advanced and standard ME images with virtual photon energies from 40 to 130 keV, respectively. In-stent luminal diameter was measured and compared to nominal lumen diameter to determine stent lumen visibility. Contrast-to-noise ratio was calculated. Advanced ME reconstructions substantially increased lumen visibility in comparison to SE for stents ≤3 mm. 130 keV images produced the best mean lumen visibility: 86 % for the 2.25 mm stent (82 % for standard ME and 64 % for SE) and 82 % for the 3.0 mm stent (77 % for standard ME and 69 % for SE). Mean DLP for SE 120 kV and DE acquisitions were 114.4 ± 9.8 and 58.9 ± 2.2 mGy x cm, respectively. DECT with advanced ME reconstructions improves the in-lumen visibility of small stents in comparison with standard ME and SE imaging. (orig.)

  14. Alternative technique using dual source CT imaging for assessment of myocardial perfusion

    Directory of Open Access Journals (Sweden)

    Amgad S. Abdel-Rahman

    2015-06-01

    Conclusion: We propose that comprehensive evaluation of coronary artery morphology and myocardial perfusion in patients with CAD could be achieved by single reproducible non-invasive contrast enhanced CT acquisition using DSCT scanners while operated in single energy mode with high sensitivity, specificity and diagnostic accuracy, it also has the potential to be the first, independent and stand out imaging choice in such field.

  15. High-pitch dual-source CT angiography of the aortic valve-aortic root complex without ECG-synchronization

    Energy Technology Data Exchange (ETDEWEB)

    Karlo, Christoph; Leschka, Sebastian; Goetti, Robert Paul; Feuchtner, Gudrun; Desbiolles, Lotus; Stolzmann, Paul; Marincek, Borut; Baumueller, Stephan [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland); Plass, Andre; Falk, Volkmar [University Hospital Zurich, Clinic for Cardiovascular Surgery, Zurich (Switzerland); Alkadhi, Hatem [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland); Massachusetts General Hospital, Harvard Medical School, Cardiac MR PET CT Group, Boston, MA (United States)

    2011-01-15

    To compare image quality and radiation dose of high-pitch computed tomography angiography(CTA) of the aortic valve-aortic root complex with and without prospective ECG-gating compared to a retrospectively ECG-gated standard-pitch acquisition. 120 patients(mean age 68 {+-} 13 years) were examined using a 128-slice dual-source CT system using prospectively ECG-gated high-pitch(group A; n = 40), non-ECG-gated high-pitch(group B; n = 40) or retrospectively ECG-gated standard-pitch(C; n = 40) acquisition techniques. Image quality of the aortic root, valve and ascending aorta including the coronary ostia was assessed by two independent readers. Image noise was measured, radiation dose estimates were calculated. Interobserver agreement was good({kappa} = 0.64-0.78). Image quality was diagnostic in 38/40 patients(group A), 37/40(B) and 38/40(C) with no significant difference in number of patients with diagnostic image quality among all groups (p = 0.56). Significantly more patients showed excellent image quality in group A compared to groups B and C(each, p < 0.01). Average image noise was significantly different between all groups(p < 0.05). Mean radiation dose estimates in groups A and B(each; 2.4 {+-} 0.3 mSv) were significantly lower compared to group C(17.5 {+-} 4.4 mSv; p < 0.01). High-pitch dual-source CTA provides diagnostic image quality of the aortic valve-aortic root complex even without ECG-gating at 86% less radiation dose when compared to a standard-pitch ECG-gated acquisition. (orig.)

  16. High-pitch dual-source CT angiography of supra-aortic arteries: assessment of image quality and radiation dose

    Energy Technology Data Exchange (ETDEWEB)

    Korn, A.; Fenchel, M.; Bender, B.; Danz, S.; Ernemann, U. [Department of Diagnostic und Interventional Neuroradiology, Tuebingen (Germany); Thomas, C.; Ketelsen, D.; Claussen, C.D.; Heuschmid, M. [Department of Diagnostic und Interventional Radiology, Tuebingen (Germany); Moonis, G. [Beth Israel Deaconess Medical Center, Department of Radiology, Boston, MA (United States); Krauss, B. [Siemens AG, Imaging and Therapy Division, Forchheim (Germany); Brodoefel, H. [Department of Diagnostic und Interventional Radiology, Tuebingen (Germany); Beth Israel Deaconess Medical Center, Department of Radiology, Boston, MA (United States); Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, MA (United States)

    2013-04-15

    High-pitch CT angiography (CTA) is a recent innovation that allows significant shortening of scan time with volume coverage of 43 mm per second. The aim of our study was to assess this technique in CTA of the head and neck. CTA of supra-aortic arteries was performed in 50 patients using two acquisition protocols: conventional single-source 64-slice (pitch 1.2) and high-pitch dual-source 128-slice CT (pitch 3.2). Subjective and objective image quality of supra-aortic vessel ostia as well as intra- and extra-cranial segments was retrospectively assessed by blinded readers and radiation dose compared between the two protocols. Conventional and high-pitch CTA achieved comparable signal-to-noise ratios in arterial (54.3 {+-} 16.5 versus 57.3 {+-} 14.8; p = 0.50) and venous segments (15.8 {+-} 6.7 versus 18.9 {+-} 8.9; p = 0.21). High-pitch scanning was, however, associated with sharper delineation of vessel contours and image quality significantly improved at the level of supra-aortic vessel ostia (p < 0.0001) as well as along the brachiocephalic trunk (p < 0.0001), the subclavian arteries (p < 0.0001), proximal common carotid arteries (p = 0.01), and vertebral V1 segments (p < 0.0001). Using the high-pitch mode, the dose-length product was reduced by about 35 % (218.2 {+-} 30 versus 141.8 {+-} 20 mGy x cm). Due to elimination of transmitted cardiac motion, high-pitch CTA of the neck improves image quality in the proximity of the aortic arch while significantly lowering radiation dose. The technique thus qualifies as a promising alternative to conventional spiral CTA and may be particularly useful for identification of ostial stenosis. (orig.)

  17. Update on multidetector coronary CT angiography of coronary stents: in vitro evaluation of 29 different stent types with dual-source CT.

    Science.gov (United States)

    Maintz, David; Burg, Matthias C; Seifarth, Harald; Bunck, Alexander C; Ozgün, Murat; Fischbach, Roman; Jürgens, Kai Uwe; Heindel, Walter

    2009-01-01

    The aim of this study was to test a large sample of the latest coronary artery stents using four image reconstruction approaches with respect to lumen visualization, lumen attenuation, and image noise in dual-source multidetector row CT (DSCT) in vitro and to provide a CT catalogue of currently used coronary artery stents. Twenty-nine different coronary artery stents (19 steel, 6 cobalt-chromium, 2 tantalum, 1 iron, 1 magnesium) were examined in a coronary artery phantom (vessel diameter 3 mm, intravascular attenuation 250 HU, extravascular density -70 HU). Stents were imaged in axial orientation with standard parameters: 32 x 0.6 collimation, pitch 0.24, 400 mAs, 120 kV, rotation time 0.33 s. Image reconstructions were obtained with four different convolution kernels (soft, medium-soft, standard high-resolution, stent-dedicated). To evaluate visualization characteristics of the stent, the lumen diameter, intraluminal density, and noise were measured. The stent-dedicated kernel offered best average lumen visualization (54 +/- 8.3%) and most realistic lumen attenuation (222 +/- 44 HU) at the expense of increased noise (23.9 +/- 1.9 HU) compared with standard CTA protocols (p magnesium stent showed the least artifacts with a lumen visibility of 90%. The majority of stents (79%) exhibited a lumen visibility of 50-59%. Less than half of the stent lumen was visible in only six stents. Stent lumen visibility largely varies depending on the stent type. Magnesium is by far more favorable a stent material with regard to CT imaging when compared with the more common materials steel, cobalt-chromium, or tantalum. The magnesium stent exhibits a lumen visibility of 90%, whereas the majority of the other stents exhibit a lumen visibility of 50-59%.

  18. Update on multidetector coronary CT angiography of coronary stents: in vitro evaluation of 29 different stent types with dual-source CT

    Energy Technology Data Exchange (ETDEWEB)

    Maintz, David; Burg, Matthias C.; Seifarth, Harald; Bunck, Alexander C.; Oezguen, Murat; Juergens, Kai Uwe; Heindel, Walter [University of Muenster, Department of Clinical Radiology, Muenster (Germany); Fischbach, Roman [University of Muenster, Department of Clinical Radiology, Muenster (Germany); Asklepios Klinikum Altona, Department of Radiology and Nuclear Medicine, Hamburg (Germany)

    2009-01-15

    The aim of this study was to test a large sample of the latest coronary artery stents using four image reconstruction approaches with respect to lumen visualization, lumen attenuation, and image noise in dual-source multidetector row CT (DSCT) in vitro and to provide a CT catalogue of currently used coronary artery stents. Twenty-nine different coronary artery stents (19 steel, 6 cobalt-chromium, 2 tantalum, 1 iron, 1 magnesium) were examined in a coronary artery phantom (vessel diameter 3 mm, intravascular attenuation 250 HU, extravascular density -70 HU). Stents were imaged in axial orientation with standard parameters: 32 x 0.6 collimation, pitch 0.24, 400 mAs, 120 kV, rotation time 0.33 s. Image reconstructions were obtained with four different convolution kernels (soft, medium-soft, standard high-resolution, stent-dedicated). To evaluate visualization characteristics of the stent, the lumen diameter, intraluminal density, and noise were measured. The stent-dedicated kernel offered best average lumen visualization (54{+-}8.3%) and most realistic lumen attenuation (222{+-}44 HU) at the expense of increased noise (23.9{+-}1.9 HU) compared with standard CTA protocols (p<0.001 for all). The magnesium stent showed the least artifacts with a lumen visibility of 90%. The majority of stents (79%) exhibited a lumen visibility of 50-59%. Less than half of the stent lumen was visible in only six stents. Stent lumen visibility largely varies depending on the stent type. Magnesium is by far more favorable a stent material with regard to CT imaging when compared with the more common materials steel, cobalt-chromium, or tantalum. The magnesium stent exhibits a lumen visibility of 90%, whereas the majority of the other stents exhibit a lumen visibility of 50-59%. (orig.)

  19. Prospectively ECG-triggered high-pitch spiral acquisition for coronary CT angiography using dual source CT: technique and initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Lell, Michael; Anders, Katharina [University of Erlangen, Diagnostic Radiology, Erlangen (Germany); Marwan, Mohamed; Schepis, Tiziano; Pflederer, Tobias; Kuettner, Axel; Ropers, Dieter; Daniel, Werner G.; Achenbach, Stephan [University of Erlangen, Department of Cardiology, Erlangen (Germany); Flohr, Thomas [CT Division, Siemens Healthcare, Forchheim (Germany); Eberhard-Karls-University, Institute of Diagnostic Radiology, Tuebingen (Germany); Allmendinger, Thomas; Thierfelder, Carsten [CT Division, Siemens Healthcare, Forchheim (Germany); Kalender, Willi; Ertel, Dirk [University of Erlangen, Institute of Medical Physics, Erlangen (Germany)

    2009-11-15

    We evaluated radiation exposure and image quality of a new coronary CT angiography protocol, high-pitch spiral acquisition, using dual source CT (DSCT). Coronary CTA was performed in 25 consecutive patients with a stable heart rate of 60 bpm or less after premedication, using 2 x 128 0.6-mm sections, 38.4-mm collimation width and 0.28-s rotation time. Tube settings were 100 kV/320 mAs and 120 kV/400 mAs for patients below and above 100-kg weight, respectively. Data acquisition was prospectively ECG-triggered at 60% of the R-R interval using a pitch of 3.2 (3.4 for the last 10 patients). Images were reconstructed with 75-ms temporal resolution, 0.6-mm slice thickness and 0.3-mm increment. Image quality was evaluated using a four-point scale (1 = excellent, 4 = unevaluable). Mean range of data acquisition was 113 {+-} 22 mm, mean duration was 268 {+-} 23 ms. Of 363 coronary artery segments, 327 had an image quality score of 1, and only 2 segments were rated as ''unevaluable''. Mean dose-length product (DLP) was 71 {+-} 23 mGy cm, mean effective dose was 1.0 {+-} 0.3 mSv (range 0.78-2.1 mSv). For 21 patients with a body weight below 100 kg, mean DLP was 63 {+-} 5 mGy cm (0.88 {+-} 0.07 mSv; range 0.78-0.97 mSv). Prospectively ECG-triggered high-pitch spiral CT acquisition provides high and stable image quality at very low radiation dose. (orig.)

  20. Clinical eraluation of dual-source CT enterography using dual-energy rirtual non-enhanced technique%双源 CT 小肠造影双能量虚拟平扫的临床评估

    Institute of Scientific and Technical Information of China (English)

    邓丽萍; 史晓喆; 章士正; 张峭巍

    2014-01-01

    目的:探讨64排双源 CT 小肠造影双能量虚拟平扫技术应用于临床的可行性。方法:采用双源 CT 机对39例患者进行小肠造影检查,常规行 CT 平扫以及动、静脉期对比增强双能量扫描(100 kVp/230 mAs 和 l40 kVp/178 mAs)。利用 Liver VNC 软件进行后处理,获得动、静脉期的虚拟平扫 CT 图像。以常规 CT 平扫图像作为标准,对虚拟平扫图像的质量进行评估,采用4级评分法:最高为4分(图像解剖细节清晰,完全能满足诊断),最低为1分(图像模糊,不能满足诊断)。并对常规 CT 平扫、动、静脉期双能量 CT 扫描的辐射剂量进行比较。结果:39例中有腹部病变者25例,无明显异常者14例。与常规平扫图像比较,虚拟平扫图像上所有病灶均能显示,且病灶的范围、大小亦无明显差异;两位医师对虚拟平扫图像质量的评分均>2分,两者的评分差异无统计学意义(P >0.05)。所有虚拟平扫图像完全能满足诊断要求。常规平扫、双能量动脉期、双能量静脉期扫描的剂量长度乘积(DLP)分别为(283.8750±57.1195)、(289.3750±53.1543)和(301.2917±55.3346)mGy·cm,三次扫描的 DLP 的差异无统计学意义(F =0.615,P =0.544)。结论:双源 CT 小肠造影检查时可仅进行双能量增强扫描,经后处理获得的虚拟平扫图像基本可取代常规 CT 平扫,从而可减少检查的辐射剂量。%Objectire:To investigate the clinical feasibility of dual-source CT enterography using dual-energy virtual non-enhanced CT (VNCT)technique.Methods:CT enterography were performed in 39 patients with dual source CT scan-ner,including conventional non-enhanced CT scan (CNCT),arterial and venous phase contrast-enhanced CT scan (CECT) with dual energy mode (100kVp/230mAs and 140kVp/178mAs).VNCT images of arterial and venous phase were obtained after being post

  1. Quantitative assessment of left ventricular function with dual-source CT in comparison to cardiac magnetic resonance imaging: initial findings

    Energy Technology Data Exchange (ETDEWEB)

    Busch, S.; Johnson, T.R.C.; Wintersperger, B.J.; Minaifar, N.; Bhargava, A.; Rist, C.; Reiser, M.F.; Becker, C.; Nikolaou, K. [University of Munich, Department of Clinical Radiology, Munich (Germany)

    2008-03-15

    Cardiac magnetic resonance imaging and echocardiography are currently regarded as standard modalities for the quantification of left ventricular volumes and ejection fraction. With the recent introduction of dual-source computedtomography (DSCT), the increased temporal resolution of 83 ms should also improve the assessment of cardiac function in CT. The aim of this study was to evaluate the accuracy of DSCT in the assessment of left ventricular functional parameters with cardiac magnetic resonance imaging (MRI) as standard of reference. Fifteen patients (two female, 13 male; mean age 50.8 {+-} 19.2 years) underwent CT and MRI examinations on a DSCT (Somatom Definition; Siemens Medical Solutions, Forchheim, Germany) and a 3.0-Tesla MR scanner (Magnetom Trio; Siemens Medical Solutions), respectively. Multiphase axial CT images were analysed with a semiautomatic region growing algorithms (Syngo Circulation; Siemens Medical Solutions) by two independent blinded observers. In MRI, dynamic cine loops of short axis slices were evaluated with semiautomatic contour detection software (ARGUS; Siemens Medical Solutions) independently by two readers. End-systolic volume (ESV), end-diastolic volume (EDV), ejection fraction (EF) and stroke volume (SV) were determined for both modalities, and correlation coefficient, systematic error, limits of agreement and inter-observer variability were assessed. In DSCT, EDV and ESV were 135.8 {+-} 41.9 ml and 54.9 {+-} 29.6 ml, respectively, compared with 132.1 {+-} 40.8 ml EDV and 57.6 {+-} 27.3 ml ESV in MRI. Thus, EDV was overestimated by 3.7 ml (limits of agreement -46.1/+53.6), while ESV was underestimated by 2.6 ml (-36.6/+31.4). Mean EF was 61.6 {+-} 12.4% in DSCT and 57.9 {+-} 9.0% in MRI, resulting in an overestimation of EF by 3.8% with limits of agreement at -14.7 and +22.2%. Rank correlation rho values were 0.81 for EDV (P = 0.0024), 0.79 for ESV (P = 0.0031) and 0.64 for EF (P = 0.0168). The kappa value of inter

  2. Virtual monochromatic imaging in dual-source and dual-energy CT for visualization of acute ischemic stroke

    Science.gov (United States)

    Hara, Hidetake; Muraishi, Hiroshi; Matsuzawa, Hiroki; Inoue, Toshiyuki; Nakajima, Yasuo; Satoh, Hitoshi; Abe, Shinji

    2015-07-01

    We have recently developed a phantom that simulates acute ischemic stroke. We attempted to visualize an acute-stage cerebral infarction by using dual-energy Computed tomography (DECT) to obtain virtual monochromatic images of this phantom. Virtual monochromatic images were created by using DECT voltages from 40 to 100 keV in steps of 10 keV and from 60 to 80 keV in steps of 1 keV, under three conditions of the tube voltage with thin (Sn) filters. Calculation of the CNR values allowed us to evaluate the visualization of acute-stage cerebral infarction. The CNR value of a virtual monochromatic image was the highest at 68 keV under 80 kV / Sn 140 kV, at 72 keV under 100 kV / Sn 140 kV, and at 67 keV under 140 kV / 80 kV. The CNR values of virtual monochromatic images at voltages between 65 and 75 keV were significantly higher than those obtained for all other created images. Therefore, the optimal conditions for visualizing acute ischemic stroke were achievable.

  3. Systolic prospectively ECG-triggered dual-source CT angiography for evaluation of the coronary arteries in heart transplant recipients

    Energy Technology Data Exchange (ETDEWEB)

    Bastarrika, Gorka [Clinica Universidad de Navarra, Cardiac Imaging Unit, Pamplona (Spain); Clinica Universidad de Navarra, Department of Radiology, Pamplona (Spain); Broncano, Jordi; Arraiza, Maria; Simon-Yarza, Isabel; Pueyo, Jesus C.; Zubieta, Jose L. [Clinica Universidad de Navarra, Department of Radiology, Pamplona (Spain); Azcarate, Pedro M. [Clinica Universidad de Navarra, Cardiac Imaging Unit, Pamplona (Spain); Clinica Universidad de Navarra, Department of Cardiology, Pamplona (Spain); Levy Praschker, Beltran G.; Rabago, Gregorio [Clinica Universidad de Navarra, Department of Cardiovascular Surgery, Pamplona (Spain)

    2011-09-15

    To assess feasibility, image quality, and radiation dose of prospectively ECG-triggered coronary CT angiography (CTA) in orthotopic heart transplant (OHT) recipients. 47 consecutive OHT recipients (40 men, mean age 62.1{+-}10.9 years, mean heart rate 86.3{+-}14.4 bpm) underwent dual-source CTA to rule out coronary allograft vasculopathy in a prospectively ECG-triggered mode with data acquisition during 35% to 45% of the cardiac cycle. Two independent observers blindly assessed image quality on a per-segment and per-vessel basis using a four-point scale (1-excellent, 4-not evaluable). Scores 1-3 were considered acceptable for diagnosis. Multivariate analysis was performed to evaluate differences between image quality scores obtained at different reconstruction intervals. Effective radiation doses were calculated. 671 coronary segments were evaluated. Interobserver agreement on the image quality was {kappa}=0.75. Diagnostic image quality was observed in 93.9%, 95.5% and 93.3% of the segments at 35%, 40% and 45% reconstruction intervals. Mean image quality score was 1.5{+-}0.7 for the entire coronary tree, 1.4{+-}0.7 for the RCA, 1.6{+-}0.8 for the LCA and 1.6{+-}0.7 for the Cx at the best reconstruction interval. Estimated mean radiation dose was 4.5{+-}1.2 mSv. Systolic prospectively ECG-triggered CTA allows diagnostic image quality coronary angiograms in OHT recipients at low radiation doses. (orig.)

  4. Automated tube voltage selection for radiation dose and contrast medium reduction at coronary CT angiography using 3{sup rd} generation dual-source CT

    Energy Technology Data Exchange (ETDEWEB)

    Mangold, Stefanie [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Eberhard-Karls University Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany); Wichmann, Julian L. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Schoepf, U.J. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Medical University of South Carolina, Division of Cardiology, Department of Medicine, Charleston, SC (United States); Poole, Zachary B.; Varga-Szemes, Akos; De Cecco, Carlo N. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Canstein, Christian [Siemens Medical Solutions, Malvern, PA (United States); Caruso, Damiano [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); University of Rome ' ' Sapienza' ' , Department of Radiological Sciences, Oncology and Pathology, Rome (Italy); Bamberg, Fabian; Nikolaou, Konstantin [Eberhard-Karls University Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany)

    2016-10-15

    To investigate the relationship between automated tube voltage selection (ATVS) and body mass index (BMI) and its effect on image quality and radiation dose of coronary CT angiography (CCTA). We evaluated 272 patients who underwent CCTA with 3{sup rd} generation dual-source CT (DSCT). Prospectively ECG-triggered spiral acquisition was performed with automated tube current selection and advanced iterative reconstruction. Tube voltages were selected by ATVS (70-120 kV). BMI, effective dose (ED), and vascular attenuation in the coronary arteries were recorded. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Five-point scales were used for subjective image quality analysis. Image quality was rated good to excellent in 98.9 % of examinations without significant differences for proximal and distal attenuation (all p ≥.0516), whereas image noise was rated significantly higher at 70 kV compared to ≥100 kV (all p <.0266). However, no significant differences were observed in SNR or CNR at 70-120 kV (all p ≥.0829). Mean ED at 70-120 kV was 1.5 ± 1.2 mSv, 2.4 ± 1.5 mSv, 3.6 ± 2.7 mSv, 5.9 ± 4.0 mSv, 7.9 ± 4.2 mSv, and 10.7 ± 4.1 mSv, respectively (all p ≤.0414). Correlation analysis showed a moderate association between tube voltage and BMI (r =.639). ATVS allows individual tube voltage adaptation for CCTA performed with 3{sup rd} generation DSCT, resulting in significantly decreased radiation exposure while maintaining image quality. (orig.)

  5. Critical stenosis of a right ventricle to coronary artery fistula seen at dual-source CT in a newborn with pulmonary atresia and intact ventricular septum.

    Science.gov (United States)

    Séguéla, Pierre-Emmanuel; Houyel, Lucile; Loget, Philippe; Piot, Jean-Dominique; Paul, Jean-François

    2011-08-01

    We report the case of a newborn with pulmonary atresia with intact ventricular septum and right ventricle-dependent coronary circulation. He died several weeks after a Blalock-Taussig procedure because of a progressive stenosis of the main coronary artery. We present echocardiographic and dual-source CT images of the stenosis, with autopsy correlation. To our knowledge, CT images of this quality have never been reported in a newborn. This case illustrates the extreme difficulty in prognosticating the outcome for these patients and underlines the need for a detailed neonatal coronary mapping to assess right ventricle-dependent coronary circulation.

  6. Evaluation of high-pitch dual-source CT angiography for evaluation of coronary and carotid-cerebrovascular arteries

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Kai [Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China); Li, Kuncheng, E-mail: cjr.likuncheng@vip.163.com [Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China); Han, Ruijuan [Department of Cardiology, Chaoyang Hospital, Capital Medical University, Beijing 100020 (China); Li, Wenhuan; Chen, Nan; Yang, Qi; Du, Xiangying; Wang, Chen [Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China); Liu, Guorong; Li, Yuechun [Department of Neurology Baotou Central Hospital, Inner Mongolia, Baotou 014040 (China); Zhou, Maorong [Department of Radiology, Baotou Central Hospital, Inner Mongolia, Baotou 014040 (China); Li, Ligang; Heidrun, Endt [CT BM Clinic Marketing, Siemens Healthcare, Beijing 100102 (China)

    2015-03-15

    Objectives: To explore the feasibility and diagnostic accuracy of a combined one-step high-pitch dual-source computed tomography angiography (CTA) technique for evaluation of coronary and carotid-cerebrovascular arteries. Materials and methods: 85 symptomatic patients suspected of coronary artery and cerebrovascular disease referred for simultaneous coronary and carotid-cerebrovascular CTA were included. Additional invasive angiography of the coronary and cerebral arteries was performed within 30 days in 23 and 13 patients, respectively. The objective parameters of image quality, the mean CT attenuations, image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were evaluated. The subjective image quality of vessels was also assessed by 2 independent radiologists blinded to the patients’ medical history and scan protocols. The diagnostic performance of CTA including sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for the detection or exclusion of significant artery stenosis was calculated using the chi-squared test of contingency and correlated with the results of invasive angiography representing the standard of reference. Results: Image quality was rated excellent (score 1) in 95.3% (1074/1127), good (score 2) in 3.3% (37/1127), adequate (score 3) in 1.0% (11/1127), and non-diagnostic (score 4) in 0.4% (5/1127) of coronary segments. Image quality of carotid and cerebral vessels was rated mostly excellent (score 1, 95.12% [78/82]; score 2, 3.66% [3/82]; score 3, 1.22% [1/82]). The sensitivity, specificity, PPV and NPV for the detection of coronary stenosis were 92.2% (81.1–97.7%), 95.2% (91.7–97.5%), 79.6% (67.1–89.1%) and 98.3% (95.8–99.5%), respectively. For the detection of carotid and cerebral artery stenosis, CTA demonstrated a sensitivity of 92.8% (80.5–98.4%), a specificity of 93.5% (88.3–96.8%), a PPV of 79.6% (65.6–89.7%) and a NPV of 97.9% (94.1–99.5%). The effective

  7. Screening for coronary artery disease in respiratory patients: comparison of single- and dual-source CT in patients with a heart rate above 70 bpm.

    Science.gov (United States)

    Pansini, Vittorio; Remy-Jardin, Martine; Tacelli, Nunzia; Faivre, Jean-Baptiste; Flohr, Thomas; Deken, Valérie; Duhamel, Alain; Remy, Jacques

    2008-10-01

    To evaluate the assessibility of coronary arteries in respiratory patients with high heart rates. This study was based on the comparative analysis of two paired populations of 54 patients with a heart rate >70 bpm evaluated with dual-source (group 1) and single-source (group 2) CT. The mean heart rate was 89.1 bpm in group 1 and 86.7 bpm in group 2 (P=0.26). The mean number of assessable segments per patient was significantly higher in group 1 compared to group 2 (P bpm, 35.6% for heart rates bpm, 40% for heart rates bpm, and 60% for heart rates bpm in group 1 and 11.3, 12.2, 8.8, and 10% for the corresponding thresholds in group 2 (P<0.05). In both groups of patients, coronary artery imaging was obtained from standard CT angiograms of the chest. The improvement in coronary imaging with dual-source CT suggests that high heart rates should no longer be considered as contraindications for ECG-gated CT angiograms of the chest whenever clinically relevant.

  8. The use of dual source CT in diagnosis of carotid body tumors%双源CT在颈动脉体瘤诊治中的应用

    Institute of Scientific and Technical Information of China (English)

    曹罡; 郭婷; 周长圣; 张森林; 孟昭业; 杨震; 董震; 徐金科; 毛钊

    2011-01-01

    Objective To evaluate the value of dual source CT in diagnosis and treatment of carotid body tumors.Methods Between Sep, 2007 and April 2010, a total of 5 patients who were planed to be diagnosed as carotid body underwent dual source CT.The relationship of the tumour and the near vessels, and the character of the tumor were identified by analysis of clinical signs and imaging results.The risk factors and feasibility of operations were evaluated before done.The tumors were resected.Results The clear edge mass of soft tissue was shown in all 5 patients in dual source CT images at the bifurcation of the common carotid artery.The minors presented obviously enhanced high-density after contrast media administration.The tumors have plenty blood supply.4 patients with small tumor in only one side show especially “cup-sign”.One female patient with bilateral tumors didn't have“ cup-sign” and significant narrow blood vessel, however the tumors were much bigger.5 patients were all diagnosed by dual source CT.The tumonrs were resected and reserved common carotid artery and internal carotid artery.Couclusion Dual source CT is convenience, non-trauma.Its information can be composited.It can offer overall image information of the blood vessel disease such as CBT, which is very important for diagnosis, typing, evaluation the risk of the operation of CBT.So, dual source CT can be the first choice in the diagnosis of carotid body tumor.%目的 评价双源CT(dual source CT,DSCT)在颈动脉体瘤(carotid body tumor,CBT)诊断、治疗中的价值.方法 2007年9月至2010年4月对临床拟诊CBT的5例行颈部双源CT检查,根据临床体征及影像学检查确定肿瘤的性质及其与颈总、颈内、颈外动脉的关系,评估手术的风险及可行性.结果 5例DSCT检查结果均显示颈总动脉分叉处界线清晰的软组织实性肿块.增强扫描后病灶均呈明显强化,瘤体血供丰富.4例单侧瘤体较小CBT呈现典型的"高脚杯"征.1例双

  9. Dual-Source CT Angiography of Peripheral Arterial Stents: In Vitro Evaluation of 22 Different Stent Types

    Directory of Open Access Journals (Sweden)

    Michael Köhler

    2011-01-01

    Full Text Available Purpose. To test different peripheral arterial stents using four image reconstruction approaches with respect to lumen visualization, lumen attenuation and image noise in dual-source multidetector row CT (DSCT in vitro. Methods and Materials. 22 stents (nitinol, steel, cobalt-alloy, tantalum, platinum alloy were examined in a vessel phantom. All stents were imaged in axial orientation with standard parameters. Image reconstructions were obtained with four different convolution kernels. To evaluate visualization characteristics of the stent, the lumen diameter, intraluminal density and noise were measured. Results. The mean percentage of the visible stent lumen diameter from the nominal stent diameter was 74.5% ± 5.7 for the medium-sharp kernel, 72.8% ± 6.4 for the medium, 70.8% ± 6.4 for the medium-smooth and 67.6% ± 6.6 for the smooth kernel. Mean values of lumen attenuation were 299.7HU ± 127 (medium-sharp, 273.9HU ± 68 (medium, 270.7HU ± 53 (medium-smooth and 265.8HU ± 43. Mean image noise was: 54.6 ± 6.3, 20.5 ± 1.7, 16.3 ± 1.7, 14.0 ± 2 respectively. Conclusion. Visible stent lumen diameter varies depending on stent type and scan parameters. Lumen diameter visibility increases with the sharpness of the reconstruction kernel. Smoother kernels provide more realistic density measurements inside the stent lumen and less image noise.

  10. Comparison of low-dose sequences of dual-source CT and echocardiography for preoperative evaluation of aortic valve disease

    Institute of Scientific and Technical Information of China (English)

    FENG Juan; WANG Xi-ming; JI Xiao-peng; LI Hai-ou; LI Qiao; GUO Wen-bin; WANG Zheng-jun

    2013-01-01

    Background Accurate evaluation of coronary artery,aortic valve annulus diameter (AVAD),and cardiac function in patients with aortic valve disease is of great significance for surgical strategy.In this study,we explored the preoperative evaluation of low-dose sequence (MinDose sequence) scan of dual-source CT (DSCT) for those patients.Methods Forty patients suspected for aortic valve disease (the experimental group) underwent MinDose sequence of DSCT to observe coronary artery,AVAD,and left ventricular ejection fraction (LVEF).Another 33 subjects suspected for coronary artery disease (the control group) underwent conventional retrospective electrocardiographically-gated sequence of DSCT.Two-dimensional transthoracic echocardiography (2D-TTE) and four-dimensional transthoracic echocardiography (4D-TTE) were applied in the experimental group to measure AVAD and LVEF and compared with MinDose-DSCT.Results There was a strong correlation between LVEFs measured by 2D-TTE and MinDose-DSCT (r=0.87,P <0.01),as well as between 4D-TTE and MinDose-DSCT (r=0.90,P <0.01).AVAD measured by MinDose-DSCT was in good agreement with corresponding measurements by 2D-TTE (r=0.90,P <0.01).The effective dose in the experimental group was 63.54% lower than that in the control group.Conclusions MinDose sequence of DSCT with a low radiation dose serving as a one-stop preoperative evaluation makes effective assessment of the coronary artery,AVAD,and LVEF for patients with aortic valve disease.

  11. Third-generation dual-source 70-kVp chest CT angiography with advanced iterative reconstruction in young children: image quality and radiation dose reduction

    Energy Technology Data Exchange (ETDEWEB)

    Rompel, Oliver; Janka, Rolf; Lell, Michael M.; Uder, Michael; Hammon, Matthias [University Hospital Erlangen, Department of Radiology, Erlangen (Germany); Gloeckler, Martin; Dittrich, Sven [University Hospital Erlangen, Department of Pediatric Cardiology, Erlangen (Germany); Cesnjevar, Robert [University Hospital Erlangen, Department of Pediatric Cardiac Surgery, Erlangen (Germany)

    2016-04-15

    Many technical updates have been made in multi-detector CT. To evaluate image quality and radiation dose of high-pitch second- and third-generation dual-source chest CT angiography and to assess the effects of different levels of advanced modeled iterative reconstruction (ADMIRE) in newborns and children. Chest CT angiography (70 kVp) was performed in 42 children (age 158 ± 267 days, range 1-1,194 days). We evaluated subjective and objective image quality, and radiation dose with filtered back projection (FBP) and different strength levels of ADMIRE. For comparison were 42 matched controls examined with a second-generation 128-slice dual-source CT-scanner (80 kVp). ADMIRE demonstrated improved objective and subjective image quality (P <.01). Mean signal/noise, contrast/noise and subjective image quality were 11.9, 10.0 and 1.9, respectively, for the 80 kVp mode and 11.2, 10.0 and 1.9 for the 70 kVp mode. With ADMIRE, the corresponding values for the 70 kVp mode were 13.7, 12.1 and 1.4 at strength level 2 and 17.6, 15.6 and 1.2 at strength level 4. Mean CTDI{sub vol}, DLP and effective dose were significantly lower with the 70-kVp mode (0.31 mGy, 5.33 mGy*cm, 0.36 mSv) compared to the 80-kVp mode (0.46 mGy, 9.17 mGy*cm, 0.62 mSv; P <.01). The third-generation dual-source CT at 70 kVp provided good objective and subjective image quality at lower radiation exposure. ADMIRE improved objective and subjective image quality. (orig.)

  12. Imaging the Parasinus Region with a Third-Generation Dual-Source CT and the Effect of Tin Filtration on Image Quality and Radiation Dose.

    Science.gov (United States)

    Lell, M M; May, M S; Brand, M; Eller, A; Buder, T; Hofmann, E; Uder, M; Wuest, W

    2015-07-01

    CT is the imaging technique of choice in the evaluation of midface trauma or inflammatory disease. We performed a systematic evaluation of scan protocols to optimize image quality and radiation exposure on third-generation dual-source CT. CT protocols with different tube voltage (70-150 kV), current (25-300 reference mAs), prefiltration, pitch value, and rotation time were systematically evaluated. All images were reconstructed with iterative reconstruction (Advanced Modeled Iterative Reconstruction, level 2). To individually compare results with otherwise identical factors, we obtained all scans on a frozen human head. Conebeam CT was performed for image quality and dose comparison with multidetector row CT. Delineation of important anatomic structures and incidental pathologic conditions in the cadaver head was evaluated. One hundred kilovolts with tin prefiltration demonstrated the best compromise between dose and image quality. The most dose-effective combination for trauma imaging was Sn100 kV/250 mAs (volume CT dose index, 2.02 mGy), and for preoperative sinus surgery planning, Sn100 kV/150 mAs (volume CT dose index, 1.22 mGy). "Sn" indicates an additional prefiltration of the x-ray beam with a tin filter to constrict the energy spectrum. Exclusion of sinonasal disease was possible with even a lower dose by using Sn100 kV/25 mAs (volume CT dose index, 0.2 mGy). High image quality at very low dose levels can be achieved by using a Sn100-kV protocol with iterative reconstruction. The effective dose is comparable with that of conventional radiography, and the high image quality at even lower radiation exposure favors multidetector row CT over conebeam CT. © 2015 by American Journal of Neuroradiology.

  13. 双源 CT 在诊断右室双出口中的应用%Application of dual source CT in the diagnosis of double outlet right ventricle

    Institute of Scientific and Technical Information of China (English)

    吴健; 马延贺; 张洪

    2015-01-01

    Objective:To investigate the value of dual source CT in the diagnosis of double outlet right ventricle (DORV)and anatomic deformities of complex congenital heart disease.Methods:The clinical materials of 17 patients with double outlet right ventricle diagnosed by dual source CT and confirmed by angiocardiography or surgery were analyzed ret-rospectively.The relationship between visceral and atrium,atrium ventricle connection,ventricular vascular connection based on the section analysis were studied.The DORV were classified and the anatomic deformities were identified,which were compared with echocardiography findings.Results:All of the 17 cases of DORV were all diagnosed by dual source CT accu-rately,while only 14 cases were accurately diagnosed by echocardiography.17 cases were classified by dual source CT and echocardiography as subaotic type (10 cases and 8 cases respectively),subpulmonary type (4 cases and 3 cases respective-ly),subpulmonary and subaortic type (one case and one case respectively),abnormality distal to great arteries (2 cases and 2 cases respectively).47 concomitant anatomic deformities of 15 kinds were diagnosed by dual source CT and only 2 were missed with atrial septal defect and patent ductus arteriosus for one case each.Treatment of 11 patients included surgical operation or trans-catheter closure via cardioangiography.Conclusion:Accurate diagnosis and classification of DORV could be obtained by dual source CT,which can provid important guidance for surgical treatment.%目的:探讨双源 CT 对右室双出口(DORV)的诊断价值及对复杂先心病解剖畸形的确诊价值。方法:回顾性分析17例经双源 CT 诊断并经心血管造影、手术等确认为右室双出口的病例资料。通过节段分析法分析内脏-心房关系、心房-心室连接、心室-大血管连接等内容,对 DORV 进行分型并确定解剖畸形,并与超声心动图进行对比。结果:17例DORV 均经双源 CT

  14. Differential diagnosis of osteoblastic metastases from bone islands in patients with lung cancer by single-source dual-energy CT: Advantages of spectral CT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Yue, E-mail: dyy1026@sina.com [Department of Radiology, The First Affiliated Hospital of Dalian Medical University, LiaoNing 116011 (China); Zheng, Shaowei, E-mail: chouxiong@sohu.com [Department of Radiology, The First Affiliated Hospital of Dalian Medical University, LiaoNing 116011 (China); Machida, Haruhiko, E-mail: machira@dnh.twmu.ac.jp [Department of Radiology, Tokyo Women' s Medical University Medical Center East, Tokyo 116-8567 (Japan); Wang, Bing, E-mail: wangbing19831003@163.com [Department of Radiology, The First Affiliated Hospital of Dalian Medical University, LiaoNing 116011 (China); Liu, Ailian, E-mail: dmu_liuailian@126.com [Department of Radiology, The First Affiliated Hospital of Dalian Medical University, LiaoNing 116011 (China); Liu, Yijun, E-mail: yijunliu1965@126.com [Department of Radiology, The First Affiliated Hospital of Dalian Medical University, LiaoNing 116011 (China); Zhang, Xin, E-mail: zhhw2000@126.com [Department of Nuclear Medicine, The First Affiliated Hospital of Dalian Medical University, Liaoning 116011 (China)

    2015-05-15

    Highlights: • Spectral CT were useful for the follow-up of spinal lesions in patients with lung cancer. • Spectral CT were useful for more accurate differential diagnosis of OBMs and BIs. • 110 keV virtual monochromatic images were the optimal for providing this differentiation. - Abstract: Objectives: To evaluate the diagnostic efficacy of spectral CT for the differentiation of osteoblastic metastases (OBMs) from bone islands (BIs) in patients with lung cancer. Methods: In 94 patients with lung cancer who underwent spectral CT, focal hyperdense lesions in vertebral bodies were diagnosed as OBMs or BIs. Regions of interest were placed within each lesion to measure the mean CT value and its standard deviation (SD) on polychromatic single-energy CT (SECT) at 140 kVp and dual-energy virtual monochromatic spectral (VMS) images. The mean bone (D{sub bone(wa)}) and water densities (D{sub wa(bone)}) of each lesion were also measured. The slope (k) of the spectral curve was calculated. Independent-sample t-test was used to compare those values between OBMs and BIs. Receiver operator characteristic analysis was performed to compare the area under curve (AUC) for the differentiation of OBMs from BIs. Results: A total of 79 OBMs and 43 BIs were confirmed. The CT and SD values on SECT at 140 kVp and VMS images at 50–130 keV, k value, and D{sub bone(wa)} for OBMs were significantly lower than for BIs; D{sub wa(bone)} was significantly higher for OBMs than for BIs (p < 0.05 for all). The AUC for the SD value at 110 keV was the highest among those parameters. The optimal cut-off value for this differentiation was 68.6 HU for the SD value on VMS images at 110 keV with sensitivity of 93.0% and specificity of 93.3%. Conclusion: Spectral CT is helpful for the differentiation of OBMs from BIs in patients with lung cancer, particularly using SD of the CT value on high-energy VMS images.

  15. Application of flash dual-source CT at low radiation dose and low contrast medium dose in triple-rule-out (tro) examination.

    Science.gov (United States)

    Chen, Hong-Liang; Chen, Tian-Wu; Qiu, Li-Hua; Diao, Xian-Ming; Zhang, Chao; Chen, Li

    2015-01-01

    To evaluate the clinical imaging capacity of FLASH dual-source CT at low radiation dose and low contrast medium dose in thoracic aorta, pulmonary artery & vein and coronary artery. One hundred and eight patients of thoracalgia were randomly divided into two groups; 60 cases (group A) received dual-source CT scan in flash model at 100 KV and contrast medium dose of 74 ml combined with digital subtraction angiography (DSA) examination; 48 cases (group B) received retrospectively. ECG-triggered high-pitch spiral acquisition at 120 KV and contrast medium dose of 101 ml. Several image reconstruction techniques were adopted for coronary artery, pulmonary artery and aorta. The imaging quality and the diagnostic value of this technique were evaluated. Coronary artery stenosis of group A was compared against the results of DSA examination. The scan time in group A was obviously shorter than that of group B, i.e., t=0.7±0.1 s in group A and t=7.7±1.7 s in group A. The image reconstruction phase of coronary artery was 70.4±15.6% in group A, and the systolic phase accounted for 13.3% of the optimal reconstruction phase. Compared with group B, the radiation dose of group A decreased obviously, i.e. ED=2.7±0.7 mSv for group A and ED=21.6±6.0 mSv for group B. Moreover, less contrast agent was consumed in group A than in group B, which was 74 ml in group A and 101 ml in group B. The image quality of aorta and pulmonary artery & vein was grade 1 for all cases in group A, which was the same as with group B. The coronary artery images of group A had better quality, with score of 2.9±0.1. Of 780 segments, only 2 segments could be effectively diagnosed, showing no statistically significant differences from group B (P>0.05). The coronary artery stenosis revealed by dual-source CT for group A was not significantly different from that by DSA (P>0.05). FLASH dual-source CT scan at reduced radiation dose and reduced contrast medium dose used for triple-rule-out (TRO) examination

  16. Accuracy of dual-source CT to identify significant coronary artery disease in patients with uncontrolled hypertension presenting with chest pain: comparison with coronary angiography.

    Science.gov (United States)

    Marwan, Mohamed; Pflederer, Tobias; Schepis, Tiziano; Seltmann, Martin; Klinghammer, Lutz; Muschiol, Gerd; Ropers, Dieter; Daniel, Werner G; Achenbach, Stephan

    2012-06-01

    It has been previously reported that the sensitivity and specificity of multislice CT for detecting significant CAD (coronary artery disease) is high. Chest pain is a common presentation in patients with uncontrolled hypertension. We investigated the sensitivity and specificity of dual-source CT to detect and rule out significant CAD in patients presenting with uncontrolled hypertension accompanied by chest pain. 260 consecutive patients presenting with acute chest pain in the context of stage 2 hypertension (systolic pressure ≥160 and/or diastolic pressure ≥100) were enrolled in the study. After admission, control of blood pressure and risk stratification, 82 patients were excluded due to renal insufficiency, prior coronary revascularisation or refused participation in the study. 90 further patients with low pre-test probability of CAD were also excluded. 88 remaining patients were subjected to CT coronary angiography using dual-source CT (Definition, Siemens Medical Solutions, Forchheim, Germany) within 24 h before invasive coronary angiography. A contrast-enhanced volume dataset was acquired (120 kV, 400 mAs/rot, collimation 2 × 64 × 0.6 mm, retrospective ECG gating). Data sets were evaluated concerning the presence or absence of significant coronary stenoses and validated against invasive coronary angiography. A significant stenosis was assumed if the diameter reduction was ≥50%. 88 patients (mean age 66 ± 11 years, mean heart rate 61 ± 9 bpm) were evaluated regarding the presence or absence of significant CAD (at least one stenosis ≥50% diameter reduction). Mean systolic blood pressure on presentation was 203 ± 20 mmHg and mean diastolic blood pressure was 103 ± 13 mmHg. On a per patient basis, the sensitivity and specificity for dual-source CT to detect significant CAD in vessels >1.5 mm diameter was 100% (36/36, 95% CI 90-100) and 90% (47/52, 95% CI 79-97), respectively with a negative predictive value (NPV) of 100% (47/47, 95% CI 92-100) and a

  17. CT diagnosis of dual source for pulmonary embolism%肺动脉栓塞的炫速双源CT诊断

    Institute of Scientific and Technical Information of China (English)

    邢漠

    2015-01-01

    Objective: To investigae and analyze the CT diagnostic performance of dual source for pulmonary embolism.Methods: he records of 35 cases with pulmonary embolism from August 2012 to April 2015 were retrospectively analyzed by prior implementation of Hyun-speed dual-source CT scan followed by the elbow injection omnipaque or ultravist,the implementation of the second scan was delayed by 30 s.Finally,the results of diagnosis were observed and analyzed.Results: Hyun-speed dual-source CT scan examination diagnosed: 18 patients with markings sparse,16 patients of pulmonary infarction form,5 patients with pulmonary hypertension,11 patients with pleural effusion and 6 patients with pleural thickening.After enhanced scan,the majority of patients with arterial filling defect tiny face.Conclusion: Hyun-speed dual-source CT scanning for diagnosis of pulmonary embolism has advantage of being fast with good image clarity providing timely scan with safety and clear scannings.It can depict variety of small lesions.%目的:探讨分析肺动脉栓塞的炫速双源CT诊断效果.方法:采取回顾性分析法,抽取2012年8月—2015年4月经临床确诊的35例肺动脉栓塞患者,事先实施炫速双源CT平扫,而后经肘注射欧乃派克或者优维显,延迟30 s后实施第2次扫描,观察分析检查诊断结果.结果:经炫速双源CT平扫检查,有18例患者肺纹理稀疏,16例患者肺梗死灶形成,5例患者肺动脉高压,11例患者胸腔积液,6例患者胸膜肥厚.经增强扫描检查后,大部分患者充盈缺损与动脉面细小.结论:采用炫速双源CT扫描诊断肺动脉栓塞,速度快且图像清晰,可及时扫描并观察各种小病灶,安全有效.

  18. Study on Clinical Application of of the Dual Energy Technique of Dual Source CT in Kidney Lesions%肾脏占位性病变中双源CT双能量技术的应用研究

    Institute of Scientific and Technical Information of China (English)

    马海鸿; 赵波; 周应恩

    2016-01-01

    目的:探究双源CT双能量技术在肾脏占位性病变的临床应用价值。方法选择2012年1月至2014年8月在新疆喀什地区第二人民医院接受治疗的肾脏占位性病变患者78例。分别采用常规CT扫描和双源CT双能量技术的增强扫描。将双源CT增强扫描结果记为观察组,常规CT扫描记为对照组。对比两组扫描图像及CT值,以及辐射剂量。结果观察组所收集的图像92.31%(72/78)的病患大部分能清晰显示,满足医师的诊断要求。并且观察组在各个部位扫描得到的CT值与对照组无显著差异且SNR显著高于对照组,而辐射剂量中的CTDIvoII、DLY以及ED均显著低于对照组。差异均有统计学意义(均P<0.05)。结论采用双源CT双能量技术对肾脏占位性病变进行诊断的图像质量较好,能满足检查的需要。此外,扫描结果中CT值可观、噪声比较低,而且辐射剂量非常低。在临床上具有较高的应用价值,值得推广应用。%Objective To explore the technique of dual source dual energy CT lesions clinical application value in the kidney. Methods 78 cases of renal occupying lesionsin was in the Second People's Hospital of Xinjiang Kashi Region for treatment From January 2012 to August 2014. Enhanced scan were used routine CT scan and dual energy technique of dual source CT. The dual source CT scan results recorded in the observation group, routine CT scan as control group, compared the two groups of images and the CT value, and the radiation dose. Results In the observation group, 92.31%(72/78) the patients of the collected most of the image display, to meet the requirements of medical diagnosis. And the observation group in each part of scanning CT value had no significant difference with control group and SNR was significantly higher than that of control group, and the radiation dose of CTDIvoII, DLY and ED were significantly lower than those of the control group. The differences

  19. Unenhanced third-generation dual-source chest CT using a tin filter for spectral shaping at 100 kVp

    Energy Technology Data Exchange (ETDEWEB)

    Haubenreisser, Holger, E-mail: holger.haubenreisser@medma.uni-heidelberg.de [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany); Meyer, Mathias; Sudarski, Sonja [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany); Allmendinger, Thomas [Siemens Healthcare Sector, CT Division, Forchheim (Germany); Schoenberg, Stefan O.; Henzler, Thomas [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany)

    2015-08-15

    Highlights: • Spectral shaping can be done using an additional tin filter. • Spectral shaping can lead to a significantly lower dose for non-contrast CT. • The low dose protocol maintains sufficient image quality for diagnosis. • The protocol used should be used for non-contrast enhanced chest CT when possible. - Abstract: Objective: To prospectively investigate image quality and radiation dose of 100 kVp spectral shaping chest CT using a dedicated tin filter on a 3rd generation dual-source CT (DSCT) in comparison to standard 100 kVp chest CT. Methods: Sixty patients referred for a non-contrast chest on a 3rd generation DSCT were prospectively included and examined at 100 kVp with a dedicated tin filter. These patients were retrospectively matched with patients that were examined on a 2nd generation DSCT at 100 kVp without tin filter. Objective and subjective image quality was assessed in various anatomic regions and radiation dose was compared. Results: Radiation dose was decreased by 90% using the tin filter (3.0 vs 0.32 mSv). Soft tissue attenuation and image noise was not statistically different for both examination techniques (p > 0.05), however image noise was found to be significantly higher in the trachea when using the additional tin filter (p = 0.002). SNR was found to be statistically similar in pulmonary tissue, significantly lower when measured in air and significantly higher in the aorta for the scans on the 3rd generation DSCT. Subjective image quality with regard to overall quality and image noise and sharpness was not statistically significantly different (p > 0.05). Conclusion: 100 kVp spectral shaping chest CT by means of a tube-based tin-filter on a 3rd generation DSCT allows 90% dose reduction when compared to 100 kVp chest CT on a 2nd generation DSCT without spectral shaping.

  20. Clinical application of dual-source CT in the evaluation of patients with lung cancer: correlation with perfusion scintigraphy and pulmonary function tests.

    Science.gov (United States)

    Fraioli, F; Serra, G; Liberali, S; Fiorelli, A; Liparulo, V; Zaccagna, F; Ciccariello, G; Catalano, C; Passariello, R

    2011-09-01

    This study was done to assess the diagnostic potential of dual-source computed tomography (DSCT) in the functional evaluation of lung cancer patients undergoing surgical resection. The CT data were compared with pulmonary perfusion scintigraphy and pulmonary function tests (PFTs). All patients were evaluated with DSCT, scintigraphy and PFTs. The DSCT scan protocol was as follows: two tubes (80 and 140 kV; Care Dose protocol); 70 cc of contrast material (5 cc/s); 5- to 6-s scan time; 0.6 mm collimation. After the automatic calculation of lung perfusion with DSCT and quantification of air volumes and emphysema with dedicated software applications, the perfusional CT studies were compared with scintigraphy using a visual score for perfusion defects; CT air volumes and emphysema were compared with PFTs. The values of accuracy, sensitivity, specificity and positive (PPV) and negative (NPV) predictive values of DSCT compared with perfusion scintigraphy as the reference standard were: 0.88, 0.84, 0.90, 0.93 and 0.88, respectively. The McNemar test did not identify significant differences either between the two imaging techniques (p=0.07) or between CT and PFTs (p=0.09). DSCT is a robust and promising technique that provides important and accurate information on lung function.

  1. Diagnostic accuracy of dual-source CT coronary angiography: The effect of average heart rate, heart rate variability, and calcium score in a clinical perspective

    Energy Technology Data Exchange (ETDEWEB)

    Long-Jiang Zhang; Zhuo-Li Zhang; Chang-Sheng Zhou; Guang-Ming Lu (Dept. of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing Univ., Nanjing (China)), e-mail: cjr.luguangming@vip.163.com; Sheng-Yong Wu (Medical Imaging Inst. of Tianjin, Tianjin (China)); Jing Wang; Shi-Sen Jiang (Dept. of Cardiology, Jinling Hospital, Clinical School of Medical College, Nanjing Univ., Nanjing (China)); Ying Lu (Dept. of Radiology and Biomedical Imaging, Univ. of California, San Francisco, CA (United States))

    2010-09-15

    Background: Dual-source CT coronary angiography (CTCA) has been used to detect coronary artery disease; however, the factors with potential to affect its diagnostic accuracy remain to be defined. Purpose: To prospectively evaluate the accuracy of dual-source CTCA in diagnosing coronary artery stenosis according to conventional coronary angiography (CAG), and the effect of average heart rate, heart rate variability, and calcium score on the accuracy of CTCA. Material and Methods: A total of 113 patients underwent both dual-source CTCA and CAG. The results were used to evaluate the findings in dual-source CTCA to assess the accuracy in the diagnosis of =50% (significant stenosis) and >75% (severe stenosis) of coronary artery according to those by CAG. Patients were divided into subgroups according to their heart rate (HR), HR variability (HRV), and calcium score, and the accuracy of CTCA was further evaluated. The chi-square test was used to analyze the difference in sensitivity and specificity for the detection of =50% and >75% coronary stenosis among subgroups. The generalized estimation equation method was used in per-vessel analysis to adjust for within-patient correlation. Results: In all, 113 patients had 338 vessels and 1661 segments evaluated by CAG. Dual-source CTCA displayed 1527 segments (91.9%). Among them, 1468 segments (calcium score by CAG score 1, n=1018; score 2, n=270; score 3, n=180) were assessable in CTCA. On a per-patient analysis, the sensitivity and specificity of CTCA were 93.9% and 93.5% for significant stenosis and 86.9% and 98.1% for severe stenosis. On a per-vessel basis, the sensitivity and specificity were 90.2% and 97.1% for significant and 83.3% and 98.1% for severe stenosis. On a per-segment analysis, the sensitivity and specificity were 90.2% and 97.1% for significant and 83.3% and 98.1% for severe stenosis. Average HR had no effect on the sensitivity and specificity of CTCA (P>0.05); whereas HRV and calcium score had some effect on

  2. 双源 CT 对主动脉瓣狭窄的诊断价值%Assessment of aortic stenosis with dual-source CT

    Institute of Scientific and Technical Information of China (English)

    王朴飞; 吕梁; 王罡; 杨利鹏; 佘波; 安鸿飞; 周子煜

    2014-01-01

    Objective To discuss the feasibility and accuracy of dual-source CT ( DSCT) in the evaluation of aortic stenosis ( AS) with transthoracic echocardiography ( TTE) as reference.Methods A total of 53 patients who underwent both DSCT and TTE were prospectively evaluated.All of them were assessed by TTE for aortic stenosis.Maximum aortic valve area ( AVA) in systolic phase was measured with DSCT , and was compared to that index obtained from the continuity equation on TTE.The severity of AS was graded as mild , moderate , or severe according to the AVA.Linear regression analysis and Bland-Altman plots were used to compare the AVA measured by using CT and TTE.Agreement on semi-quantitative grades of AS severity between the two methods was tested by using Kappa statistics.Results The mean AVA using DSCT was (1.45 ±0.35 ) cm2 compared to the mean AVA of ( 1.33 ±0.36 ) cm2 using TTE, with a significant correlation between them (r=0.92,P<0.01).Bland-Altman analysis demonstrated good inter-modality consistency between DSCT and TTE.However , DSCT demonstrated a slight overestimation of the AVA compared to TTE.As identified by TTE, there were 53 patients with AS, 13 with mild AS, 21 with moderate AS , and 19 with severe AS.In 3 patients DSCT showed no AS , TTE detected mild AS.In 6 cases, TTE had graded the stenosis as moderate , but the stenosis degree was graded as mild using DSCT.Kappa analysis showed a good agreement between the two methods on semi -quantitative grades of aortic stenosis severity (Kappa=0.75,P<0.01).Conclusion AVA measurements using DSCT is feasible and reasonably accurate for those patients with moderate to severe aortic stenosis.%目的:以经胸心脏超声(TTE)为对照,探讨双源CT(DSCT)评估主动脉瓣狭窄(AS)的可行性及准确性。方法回顾性分析53例行DSCT冠状动脉成像及TTE检查,经TTE诊断均为AS的患者。 DSCT面积法测量收缩期最大主动脉瓣口面积(AVA),TTE采用连续性方程计

  3. Application of dual-source CT in diagnosis of common atrioventricular canal%双源CT在共同房室通道诊断中的应用

    Institute of Scientific and Technical Information of China (English)

    冯越; 刘铁; 翟利浩

    2012-01-01

    目的 探讨双源CT(DSCT)在共同房室通道(CAC)诊断中的应用价值.方法 选取9例CAC患儿,采用DSCT心电门控下对比增强完成心脏检查,并在图像工作站完成多平面(MPR)、最大密度投影(MIP)和三维容积漫游(VR)处理.同期所有患儿均完成超声心动图检查.比较两种检查方法的诊断结果.结果 DSCT均作出CAC诊断,共发现合并畸形29处;超声心动图亦均作出CAC诊断,共发现合并畸形16处.结论 DSCT可以对CAC患儿作出准确诊断,较之超声心动图能发现更多合并畸形,有助于临床手术方案的制定与完善.%Objective To evaluate the clinical values of dual-source CT (DSCT) in diagnosis of common atrioventricular canal. Methods Nine children aged 135 days to 6 y with common atrioventricular canal (CAC) underwent dual-source cardiac CT scan. Two- and three-dimensional images were processed by means of MPR (coronal, sagital and oblique), MIP and VR. E-chocardiography was performed in all cases at same time; and 2 cases received surgical treatment. Results DSCT confirmed diagnosis of CAC in all 9 cases. DSCT revealed 29 concomitant anomalies and echocardiography revealed 16 in all 9 cases. Conclusion DSCT can confirm diagnosis of common atrioventricular canal, which contributes to the planning of operation and better surgical outcomes of patients.

  4. 双源双能CT在尿路结石成分分析中的应用%Dual source dual energy CT in the analysis of urinary calculi composition

    Institute of Scientific and Technical Information of China (English)

    范璐; 郭君武; 张慧

    2012-01-01

    目的:探讨双源CT双能量技术应用于尿路结石成分分析中的临床价值.方法:226例尿路结石患者行双源CT双能量扫描,对其结石成分进行分析,将结果与用红外光谱法分析结石成分的结果作对比,计算双源CT在体分析草酸钙结石、磷酸盐结石、胱氨酸结石及尿酸结石的灵敏度与特异度.结果:双源CT能够准确的区分尿酸结石和非尿酸结石(灵敏度和特异度均为100%),较准确的区分草酸钙结石(灵敏度为89.03%、特异度为85.62%),磷酸盐结石(灵敏度为67.28%、特异度为90.71%)及胱氨酸结石(灵敏度为73.56%、特异度为93.43%).结论:双源CT双能量技术能在治疗前对尿路结石的成分进行初步分析,对了解结石成因,预防结石形成及指导治疗具有重要的意义.%Objective: To assess the clinical value of dual source dual energy CT in the analysis of urinary calculi composition. Methods:Dual-source CT with dual-energy scanning technique was performed in 226 patients with urinary calculi. The composition of urinary stones was compared with the results of the urinary stones composition analyzed by Fourier transform infrared spectroscopy (FTIR). The sensitivity and specificity of dual energy CT in evaluating the composition of calcium oxalate stone, phosphate stone, cystine stone and uric acid stone in vivo were calculated. Results:Dual-source CT could accurately distinguish uric acid stones and non-uric acid stones with the sensitivity and specificity as 100% respectively. The sensitivity of differentiating calcium oxalate stone, cystine stone and phosphate stone was 89. 3%, 67. 28% and 73. 56% respectively,and the specificity of the above mentioned calculi was 85. 62%,90. 71% and 93. 43% respectively. Conclusion: Analysis of urinary calculi composition before treatment could be obtained by dual-source CT with dual-energy technique, which had significant importance to understand the causes of stone,to prevent

  5. Prospective prediction of the major component of urinary stone composition with dual-source dual-energy CT in vivo.

    Science.gov (United States)

    Zhang, G-M-Y; Sun, H; Xue, H-D; Xiao, H; Zhang, X-B; Jin, Z-Y

    2016-11-01

    To prospectively evaluate the diagnostic accuracy of dual-source dual-energy computed tomography (DSDECT) for predicting the major component and determining the composition of urinary calculi in patients with urolithiasis, using postoperative in vitro Fourier transform infrared spectroscopy (FT-IR) analysis as the reference standard. Patients with known urolithiasis underwent preoperative DSDECT evaluation, and subsequently, underwent surgical removal of the stones. All patients were examined using the dual-energy renal stone protocol. Material-specific chromatic images were made using dedicated post-processing software. The final determination of stone composition was made using FT-IR postoperatively. Diagnostic parameters of DSDECT for predicting the major component and detecting the presence of four composition types were calculated. A total of 81 urinary calculi were included in this study. Forty-three were pure stones and 38 were mixed stones according to FT-IR. DSDECT correctly identified the major component of all pure stones and 36 mixed stones. The major component of two mixed stones with uric acid as the major component was falsely interpreted as calcium oxalate. The overall accuracy of DSDECT for predicting the major component of stones was 97.5% (79/81). The accuracy of DSDECT for detecting the presence of four types of composition, uric acid, cysteine, hydroxyapatite, and calcium oxalate, was 97.5% (79/81), 93.8% (76/81), 80.2% (65/81), and 93.8% (76/81), respectively. DSDECT could accurately predict the major component of urinary calculi and detect uric acid, cysteine, and calcium oxalate with a satisfactory accuracy. Copyright © 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  6. Multiparametric Evaluation of Head and Neck Squamous Cell Carcinoma Using a Single-Source Dual-Energy CT with Fast kVp Switching: State of the Art

    Directory of Open Access Journals (Sweden)

    Stephanie Lam

    2015-11-01

    Full Text Available There is an increasing body of evidence establishing the advantages of dual-energy CT (DECT for evaluation of head and neck squamous cell carcinoma (HNSCC. Focusing on a single-source DECT system with fast kVp switching, we will review the principles behind DECT and associated post-processing steps that make this technology especially suitable for HNSCC evaluation and staging. The article will review current applications of DECT for evaluation of HNSCC including use of different reconstructions to improve tumor conspicuity, tumor-normal soft tissue interface, accuracy of invasion of critical structures such as thyroid cartilage, and reduce dental artifact. We will provide a practical approach for DECT implementation into routine clinical use and a multi-parametric approach for scan interpretation based on the experience at our institution. The article will conclude with a brief overview of potential future applications of the technique.

  7. Low-dose adaptive sequential scan for dual-source CT coronary angiography in patients with high heart rate: Comparison with retrospective ECG gating

    Energy Technology Data Exchange (ETDEWEB)

    Xu Lei, E-mail: leixu2001@hotmail.com [Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, 100029 Beijing (China); Yang Lin, E-mail: anna7949@163.com [Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, 100029 Beijing (China); Zhang Zhaoqi, E-mail: zhaoqi5000@vip.sohu.com [Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, 100029 Beijing (China); Li Yu, E-mail: athen06@hotmail.com [Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, 100029 Beijing (China); Fan Zhanming, E-mail: fanzm120@tom.com [Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, 100029 Beijing (China); Ma Xiaohai, E-mail: maxi8238@gmail.com [Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, 100029 Beijing (China); Lv Biao, E-mail: biao_lu2007@sina.com [Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, 100029 Beijing (China); Yu Wei, E-mail: yuwei02@gmail.com [Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, 100029 Beijing (China)

    2010-11-15

    Purpose: To explore feasibility of dual-source CT (DS-CT) prospective ECG-gated coronary angiography in patients with heart rate (HR) higher than 70 beat per minute (bpm), and evaluate image quality and radiation dose with comparison to retrospective ECG-gated spiral scan. Materials and methods: One hundred patients who underwent DS-CT coronary angiography (DS-CTCA) with mean HR higher than 70 bpm but below 110 bpm were enrolled in the study, 50 were scanned by adaptive sequential scan and another 50 were analyzed by retrospectively gated CT scan. The imaging quality of coronary artery segments in the two groups was evaluated using a four-point grading scale by two independent reviewers. Patient radiation dose was calculated by multiplying dose length product by conversion coefficient of 0.017. Results: There was no significant difference between the two groups for mean HR (p = 0.305), HR variability (p = 0.103), body mass index (p = 0.472), and scan length (p = 0.208). There was good agreement for image quality scoring between the two reviewers (Kappa = 0.72). Coronary evaluability of adaptive sequential scan was 99.7% (608 of 610 segments), while that of retrospective gated scan was 98.7% (614 of 622 segments), showing similar coronary evaluability (p = 0.061). Effective doses of adaptive sequential scan and retrospective gated scan were 5.1 {+-} 1.6 and 11.8 {+-} 4.5 mSv, respectively (p < 0.001), showing that adaptive sequential scan reduced radiation dose by 57% compared with that of retrospective gated scan. Conclusions: In patients with 70-110 bpm HR, DS-CTCA adaptive sequential scan shows similar image quality as retrospective ECG-gated spiral scan with 57% reduction of radiation dose.

  8. Prospective versus retrospective ECG gating for dual source CT of the coronary stent: Comparison of image quality, accuracy, and radiation dose

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Lei, E-mail: zhaolei219@sohu.com [Beijing Anzhen Hospital of the Capital University of Medical Sciences (China); Zhang Zhaoqi; Fan Zhanming; Yang Lin; Du Jing [Beijing Anzhen Hospital of the Capital University of Medical Sciences (China)

    2011-03-15

    Objective: To compare image quality, diagnostic accuracy and radiation dose of prospective and retrospective electrocardiogram (ECG) gated dual source computed tomography (DSCT) for the evaluation of the coronary stent, using conventional coronary angiography (CA) as a standard reference. Design, setting and patients: Sixty patients (heart rates {<=}70 bpm) with previous stent implantation who were scheduled for CA were divided in two groups, receiving either prospective or retrospective ECG gated DSCT separately. Two reviewers scored coronary stent image quality and evaluated stent lumen. Results: There was no significant difference in image quality between the two groups. In the prospective group, there were 86.4% (51/59) stents with interpretable images, in the retrospective group, there were 87.5% (49/56) stents with interpretable images. Image quality was not influenced by age, body mass index or heart rate in either group, but heart rate variability had a weak impact on the image quality of the prospective group. Image noise was higher in the prospective group, but this difference reached statistical significance only by using a smooth kernel reconstruction. Per-stent based sensitivity, specificity, and positive and negative predictive value were 100%, 84.1%, 68.2%, and 100%, respectively, in the prospective CT angiography group and 94.4%, 86.8%, 77.3%, and 97.1%, respectively, in the retrospective CT angiography group. There was a significant difference in the effective radiation dose between the two groups, mean effective dose in the prospective and retrospective group was 2.2 {+-} 0.5 mSv (1.5-3.2 mSv) and 14.6 {+-} 3.3 mSv (10.0-20.4 mSv) (p < .001) respectively. Conclusions: Compared with retrospective CT angiography, prospective CT angiography has a similar performance in assessing coronary stent patency, but a lower effective dose in selected patients with regular heart rates {<=}70 bpm.

  9. 泌尿系结石成分的体内双源双能量CT分析%Identification of Urinary Stone Composition with Dual-energy Acquisition of Dual-source CT in Vivo

    Institute of Scientific and Technical Information of China (English)

    凃备武; 周洁; 李惠民; 耿娟

    2013-01-01

    目的:探讨双源CT双能量技术体内分析泌尿系结石成分的可行性和准确性.方法:104例泌尿系结石患者共113结石纳入研究,全部完成双源CT双能量扫描并于工作站(syngo)上完成结石成分分析,全部结石取出后完成红外线光谱分析确定成分.结果:全部病人均顺利完成体内结石成分分析,以红外线光谱分析为参照标准,双源CT双能量分析显示尿酸、草酸钙和磷灰石成分分别得到准确性97.3%、92.9%、38.1%,灵敏度88.2%、100%、9.6%,特异度99.0%、66.7%、90.0%,阳性预测值93.8%、91.7%、63.6%,以及阴性预测值97.9%、100%、35.3%.胱氨酸盐均为假阳性.结论:双源CT双能量技术分析体内泌尿系结石成分是可行的,对尿酸和草酸钙的定性有很高的准确性,具有较高的临床实用价值.%Purpose: To investigate the clinical value of the determination of renal stone composition in vivo with dual-source dual-energy CT. Methods: One hundred and four cases with 113 renal stones were collected. All cases were scanned with dual-energy acquisition by dual-source CT. The data were sent to the workstation for the analysis of the stone composition. The urinary stones were analyzed by infrared spectroscopy after surgery. These two results were compared and the infrared spectroscopy result was taken as the reference standard. Results: The accuracy, sensitivity, specificity, positive and negative predictive value of the dual-energy CT for the diagnosis of uric acid stone were 97.3%, 88.2%, 99.0%, 93.8%, and 97.9% respectively; those of oxalate were 92.9%, 100%, 66.7%, 91.7%, 100%, and those of apatite were 38.1%, 9.6%, 90.0%, 63.6%, 35.3%. All cystine stones were with false positive results. Conclusion: Dual source dual-energy CT has high accuracy for identifying uric acid and oxalate stone in vivo and can be used clinically.

  10. Initial results of a new generation dual source CT system using only an in-plane comb filter for ultra-high resolution temporal bone imaging

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Mathias; Haubenreisser, Holger; Schoenberg, Stefan O.; Henzler, Thomas [Heidelberg University, Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Mannheim (Germany); Raupach, Rainer; Schmidt, Bernhard; Leidecker, Christianne; Allmendinger, Thomas; Flohr, Thomas [Siemens Healthcare, Imaging and Therapy Division, Forchheim (Germany); Lietzmann, Florian; Schad, Lothar R. [Heidelberg University, Computer Assisted Clinical Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Mannheim (Germany)

    2015-01-15

    To prospectively evaluate radiation dose and image quality of a third generation dual-source CT (DSCT) without z-axis filter behind the patient for temporal bone CT. Forty-five patients were either examined on a first, second, or third generation DSCT in an ultra-high-resolution (UHR) temporal bone-imaging mode. On the third generation DSCT system, the tighter focal spot of 0.2 mm{sup 2} removesthe necessity for an additional z-axis-filter, leading to an improved z-axis radiation dose efficiency. Images of 0.4 mm were reconstructed using standard filtered-back-projection or iterative reconstruction (IR) technique for previous generations of DSCT and a novel IR algorithm for the third generation DSCT. Radiation dose and image quality were compared between the three DSCT systems. The statistically significantly highest subjective and objective image quality was evaluated for the third generation DSCT when compared to the first or second generation DSCT systems (all p < 0.05). Total effective dose was 63 %/39 % lower for the third generation examination as compared to the first and second generation DSCT. Temporal bone imaging without z-axis-UHR-filter and a novel third generation IR algorithm allows for significantly higher image quality while lowering effective dose when compared to the first two generations of DSCTs. (orig.)

  11. Prevalence of first-pass myocardial perfusion defects detected by contrast-enhanced dual-source CT in patients with non-ST segment elevation acute coronary syndromes

    Energy Technology Data Exchange (ETDEWEB)

    Schepis, Tiziano; Achenbach, Stephan; Marwan, Mohamed; Muschiol, Gerd; Ropers, Dieter; Daniel, Werner G.; Pflederer, Tobias [University of Erlangen, Department of Internal Medicine 2 (Cardiology), Erlangen (Germany)

    2010-07-15

    To investigate the prevalence and diagnostic value of first-pass myocardial perfusion defects (PD) visualised by contrast-enhanced multidetector computed tomography (MDCT) in patients admitted for a first acute coronary syndrome (ACS). Thirty-eight patients with non-ST segment elevation myocardial infarction (NSTEMI) or unstable angina (UA) and scheduled for percutaneous coronary intervention underwent dual-source CT immediately before catheterisation. CT images were analysed for the presence of any PD by using a 17-segment model. Results were compared with peak cardiac troponin-I (cTnI) and angiography findings. PD were seen in 21 of the 24 patients with NSTEMI (median peak cTnI level 7.07 ng/mL; range 0.72-37.07 ng/mL) and in 2 of 14 patients with UA. PD corresponded with the territory of the infarct-related artery in 20 out of 22 patients. In a patient-based analysis, sensitivity, specificity, negative and positive predictive values of any PD for predicting NSTEMI were 88%, 86%, 80% and 91%. Per culprit artery, the respective values were 86%, 75%, 80% and 83%. In patients with non-ST segment elevation ACS, first-pass myocardial PD in contrast-enhanced MDCT correlate closely with the presence of myocardial necrosis, as determined by increases in cTnI levels. (orig.)

  12. Dual-energy imaging of bone marrow edema on a dedicated multi-source cone-beam CT system for the extremities

    Science.gov (United States)

    Zbijewski, W.; Sisniega, A.; Stayman, J. W.; Thawait, G.; Packard, N.; Yorkston, J.; Demehri, S.; Fritz, J.; Siewerdsen, J. H.

    2015-03-01

    Purpose: Arthritis and bone trauma are often accompanied by bone marrow edema (BME). BME is challenging to detect in CT due to the overlaying trabecular structure but can be visualized using dual-energy (DE) techniques to discriminate water and fat. We investigate the feasibility of DE imaging of BME on a dedicated flat-panel detector (FPD) extremities cone-beam CT (CBCT) with a unique x-ray tube with three longitudinally mounted sources. Methods: Simulations involved a digital BME knee phantom imaged with a 60 kVp low-energy beam (LE) and 105 kVp high-energy beam (HE) (+0.25 mm Ag filter). Experiments were also performed on a test-bench with a Varian 4030CB FPD using the same beam energies as the simulation study. A three-source configuration was implemented with x-ray sources distributed along the longitudinal axis and DE CBCT acquisition in which the superior and inferior sources operate at HE (and collect half of the projection angles each) and the central source operates at LE. Three-source DE CBCT was compared to a double-scan, single-source orbit. Experiments were performed with a wrist phantom containing a 50 mg/ml densitometry insert submerged in alcohol (simulating fat) with drilled trabeculae down to ~1 mm to emulate the trabecular matrix. Reconstruction-based three-material decomposition of fat, soft tissue, and bone was performed. Results: For a low-dose scan (36 mAs in the HE and LE data), DE CBCT achieved combined accuracy of ~0.80 for a pattern of BME spherical lesions ranging 2.5 - 10 mm diameter in the knee phantom. The accuracy increased to ~0.90 for a 360 mAs scan. Excellent DE discrimination of the base materials was achieved in the experiments. Approximately 80% of the alcohol (fat) voxels in the trabecular phantom was properly identified both for single and 3-source acquisitions, indicating the ability to detect edemous tissue (water-equivalent plastic in the body of the densitometry insert) from the fat inside the trabecular matrix

  13. Initial results of a new generation dual source CT system using only an in-plane comb filter for ultra-high resolution temporal bone imaging.

    Science.gov (United States)

    Meyer, Mathias; Haubenreisser, Holger; Raupach, Rainer; Schmidt, Bernhard; Lietzmann, Florian; Leidecker, Christianne; Allmendinger, Thomas; Flohr, Thomas; Schad, Lothar R; Schoenberg, Stefan O; Henzler, Thomas

    2015-01-01

    To prospectively evaluate radiation dose and image quality of a third generation dual-source CT (DSCT) without z-axis filter behind the patient for temporal bone CT. Forty-five patients were either examined on a first, second, or third generation DSCT in an ultra-high-resolution (UHR) temporal bone-imaging mode. On the third generation DSCT system, the tighter focal spot of 0.2 mm(2) removes the necessity for an additional z-axis-filter, leading to an improved z-axis radiation dose efficiency. Images of 0.4 mm were reconstructed using standard filtered-back-projection or iterative reconstruction (IR) technique for previous generations of DSCT and a novel IR algorithm for the third generation DSCT. Radiation dose and image quality were compared between the three DSCT systems. The statistically significantly highest subjective and objective image quality was evaluated for the third generation DSCT when compared to the first or second generation DSCT systems (all p generation examination as compared to the first and second generation DSCT. Temporal bone imaging without z-axis-UHR-filter and a novel third generation IR algorithm allows for significantly higher image quality while lowering effective dose when compared to the first two generations of DSCTs. • Omitting the z-axis-filter allows a reduction in radiation dose of 50% • A smaller focal spot of 0.2 mm (2) significantly improves spatial resolution • Ultra-high-resolution temporal-bone-CT helps to gain diagnostic information of the middle/inner ear.

  14. Congenital coronary artery fistulas: dual-source CT findings from consecutive 6624 patients with suspected or confirmed coronary artery disease

    Institute of Scientific and Technical Information of China (English)

    YUN Hong; ZENG Meng-su; YANG Shan; JIN Hang; YANG Xue

    2011-01-01

    Background Coronary artery fistulas (CAFs) are rare congenital abnormality often unintentionally found in patients with coronary artery disease.Clinical diagnosis of CAFs is difficult due to symptomless or lack of specific symptoms.Dual-source computed tomography (DSCT) might be a useful diagnostic tool for CAFs.The study aimed to retrospectively summarize the imaging features of CAFs delineated at DSCT in 48 CAF patients detected from consecutive 6624 patients with suspected or confirmed coronary artery disease in our institution.Methods Forty-eight patients underwent DSCT angiography by using retrospective electrocardiographic (ECG) gating after infusion of 70 ml of intravenous contrast material during breath hold.Maximum intensity projection (MIP),curved planar reconstruction (CPR),and volume rendering technique (VR) were obtained.Anomalous termination of coronary artery in each subject was evaluated by two radiologists (with more than 10 years experience with cardiovascular imaging),and disagreement between diagnosis readers was settled by a consensus reading.Ten of 48 patients also underwent traditional coronary angiography (CAG) simultaneously.Results In each CAF case,DSCT angiography clearly demonstrated the origin,the termination,the size of abnormal vessel and its course in relation to surrounding great vessels.CAF arising from right coronary artery was the most common type,left circumflex was the least one involved among three coronaries,and pulmonary artery was the most common drainage site.Aneurismal fistulous tract,coronary atherosclerosis,myocardial bridging and anomalous origin of coronary artery were also detected in this group.The demonstration of drainage sites in CAG was consistent with DSCT angiography in 9 patients,and judgment on one anomalous connection in CAG was inconsistent with that in DSCT angiography.Conclusions DSCT angiography could provide accurate delineation of anomalous communications,size and numbers of fistulas in patients with

  15. The Clinical Application Value of Dual-source CT's Dual Energy Scanning in the Diagnosis of Liver Tumor%双源CT双能量扫描诊断肝脏肿瘤临床应用价值探讨

    Institute of Scientific and Technical Information of China (English)

    余丁福

    2015-01-01

    Objective The Thesis aims to probe into the Clinical application value of dual-source CT’s dual energy scanning in the diagnosis of liver tumor.Methods We have took a comprehensive researches and analysis on the clinical image data of 50 liver tumor patients under the dual-source CT’s dual energy scan during the period of June 2013 to May 2014 in our hospital.Results With the analysis of different scan ways picked by the patients, and comparison with the value of TNE and VNC CT of the liver spleen aorta abdominalis Muscle behind muscles, it shows the difference between the two is not statistically signiifcant(P>0.05). The value of primary carcinoma of liver related with TNE and VNC CT which is relfected on the substantial iodine density image is lower than that of hepatic hemangioma and cholangiocellular carcinoma, however, the difference is statistically signiifcant.Conclusion Dual energy scanning has the potential Clinical application value in the diagnosis of liver tumor, which should get a big promotion and application.%目的:探讨双源CT双能量扫描在诊断肝脏肿瘤中的临床应用价值。方法选取2013年6月-2014年5月在该院行双源CT双能量扫描的50例肝脏肿瘤患者的临床及影像资料进行分析研究。结果针对患者选择的扫描方式不同,对比患者肝脏、脾脏、腹主动脉、肌柱后方肌肉TNE与VNC CT值,二者间的差异无统计学意义(P>0.05),原发性肝癌在实质期碘基图像上的二者数值分别低于肝血管瘤、胆管细胞癌,差异具有明显统计学意义(P<0.05)。结论双能量扫描在诊断肝脏肿瘤中具有潜在的临床应用价值,应得到推广使用。

  16. 双源CT双能量技术在痛风诊断中的初步应用%Preliminary application of dual source dual energy CT in the diagnosis of gout

    Institute of Scientific and Technical Information of China (English)

    高江晖; 李玉芳; 马洪宇; 郭文伟; 张荣恒; 李攀; 石少聪

    2016-01-01

    Objective To evaluate the effect of dual energy CT in urate crystals in extremities joints of gout. Methods Forty-two cases with gout and 12 cases as control were examinated by dual source CT. The 80 kV,140 kV and 120 kV hybrid energy were collected after one-time scaning. After scanning the image data processed within Syngo. via. Dual-Energy GOUT software,the difference between the gout group and the control group was compared. Results The 42 patients were found with hands and feet multiple urate crystals,finger( toe)between the joints and surrounding soft tissues was more seri-ous;while no gout was found in hands and feet of 12 cases of control group. Conclusions Dual source DECT technology can display the urate crystal,which can be used as routine examination for the gout screening.%目的:探讨双源CT双能量成像技术在痛风患者四肢关节尿酸盐结晶检出中的应用。方法42例痛风性关节炎患者及12例对照组患者行双源 CT双能量扫描,获得80、140 kV双能图像和120 kV混合能量图像,扫描数据在Syngo. via. Dual-Energy GOUT软件内进行图像后处理,比较痛风组与对照组痛风石的差异。结果42例患者均发现双手、双足多发尿酸盐结晶,以指(趾)间关节及周围软组织内为著,12例对照组患者双手、双足均未显示尿酸盐结晶。结论双源 CT双能量技术能明确显示尿酸盐结晶,具有较高的临床应用价值,可作为痛风筛查的常规检查项目。

  17. 双源 CT 双能量虚拟平扫对脂肪肝的诊断价值%The diagnostic value of dual energy virtual non-contrast images in hepatic steatosis with dual source CT scanner

    Institute of Scientific and Technical Information of China (English)

    王士阗; 王萱; 王禨; 徐凯; 薛华丹; 金征宇

    2014-01-01

    _目的:探讨双源 CT 双能量腹部虚拟平扫对脂肪肝的诊断价值。方法:回顾性分析采用双源 CT 行腹部双能量增强扫描诊断为脂肪肝的77例患者的平扫期(120 kV)及虚拟平扫(VNC)图像。虚拟平扫图像运用门脉期双能量(100及140 kV)图像重建而来。选择肝门层面测量真实平扫(TNC)与 VNC 图像上肝右叶、肝左叶、脾脏、下腔静脉的 CT 值及噪声,并在肝门层面测量上腹部前后径及左右径。记录整个扫描和平扫期对应的剂量长度乘积(DLP)。评价 TNC 与VNC 图像间各 CT 值及噪声的差异,分析两组图像上肝右叶噪声与前后径、左右径及平均径的关系。分别用肝/脾 CT 值比<0.8、肝/下腔静脉 CT 值比<1.0,做为诊断中重度脂肪肝的标准,比较 TNC 和 VNC 图像诊断中重度脂肪肝的一致性。结果:VNC 图像上肝左叶、右叶及脾脏的 CT 值均高于 TNC(P<0.01),差异小于10 HU。VNC 图像上各部位噪声均低于 TNC。TNC 图像上,肝右叶噪声与前后径、左右径、平均径均有中等相关性(r=0.562,0.608,P<0.01);在 VNC图像上,肝右叶噪声与上述径线值相关性弱。用肝/脾 CT 值比<0.8作为诊断重度脂肪肝的标准,VNC 与 TNC 图像诊断重度脂肪肝一致性的 kappa 值为0.591;用肝/静脉 CT 值比<1.0作为诊断标准,两种图像一致性的 kappa 值为0.458。用 VNC 代替 TNC 图像,可降低24.2%的总扫描剂量。结论:VNC 图像与 TNC 图像在诊断中重度脂肪肝上具有中等的一致性,推荐运用肝/脾 CT 值比<0.8这一诊断标准。%To investigate the value of dual energy (DE)virtual non-contrast (VNC)images in the diagno-sis of hepatic steatosis.Methods:This retrospective study was based on contrast enhanced abdominal DECT scan of 77 pa-tients with hepatic steatosis.The VNC images were reconstructed from two sets of

  18. The Value Study In Urinary Stone Composition Analysis by Dual Source CT Dual Energy Technology%双源CT双能量技术在尿路结石成分分析中的应用价值研究

    Institute of Scientific and Technical Information of China (English)

    刘志鹏; 沈剑辉; 汤连志; 姜洪

    2016-01-01

    Objective The purpose of this paper is to explore the application value of dual energy CT technology in the determination of urinary stone composition. Methods A total of 86 patients with acute abdominal pain in our hospital from September 2014 to November 2015 were selected. For patients with implementation of dual source CT examination and by scanning results analysis of stone composition, and with the stones after operation in vitro infrared spectrum analysis results, make analysis of dual source CT diagnostic value. Results DUALSOURCE CT were found in 136 pa-tients with stones in 70 cases, 57 cases of infrared spectroscopy confirmed that 98. Among them, calcium oxalate stones 86, accounting for all 87.76%(86/98);uric acid stones in 5 cases, 7, accounting for 7.14%(7/98);other stones in 4 cas-es, 5, accounting for 5.10%(5/98). Conclusion Dual source CT in urinary system stones with good accuracy, and can effectively accurately distinguish stones of different components of the composition, make accurate judgment, provide accurate reference for clinicians to the next treatment in the analysis.%目的:该文旨在探究双源CT双能量技术在尿路结石成分分析中的应用价值。方法选取2014年9月—2015年11月间于该院检查的疑似泌尿系统结石的腹部锐痛患者共86例。对患者实施双源CT检查,由扫描结果分析结石成分,并同结石术后体外红外光谱分析结果相对照,作出双源CT诊断价值分析。结果双源CT检查后共发现70例患者的136颗结石,红外光谱证实57例,98颗。其中草酸钙结石86颗,占全部的87.76%(86/98);尿酸结石5例,7颗,占全部的7.14%(7/98);其它结石4例,5颗,占全部的5.10%(5/98)。结论双源CT在分析泌尿系统结石中的准确性较好,可有效地准确区分组成成分不同的结石,作出准确的判定,为临床医生接下来的诊疗提供准确地参考依据。

  19. Application of 70 kV Third-generation High-pitch Dual-source Coronary CT Angiography in Patients with Different Body Mass Index.

    Science.gov (United States)

    Yi, Yan; Cao, Jian; Lin, Lu; Kong, Lingyan; Jiang, Shu; Li, Xiao; Liu, Peijun; Wang, Ming; Wang, Man; Wang, Yun; Jin, Zhengyu; Wang, Yining

    2017-02-20

    Objective  To investigate the optimized range of body mass index (BMI) selection for patients undergoing 70 kV high-pitch dual-source coronary CT angiography (CCTA) on the third-generation dual-source CT (DSCT). Methods  Patients undergoing prospective high-pitch ultra-low contrast media (CM) CCTA on the third-generation DSCT using the automatic tube voltage selection at 70 kV were included and divided into three groups:group A,with BMI≤24 kg/m(2);group B,with 24 kg/m(2)image quality results,and effective dose (ED) were evaluated and compared. Results  No significant difference was found in age (H=2.36,P=0.78),heart rate (H=3.51,P=0.80),and ED(H=1.77,P=0.12) among three groups. The noise of the aortic root in group A was (21.66±4.00)HU,which was significantly lower than that in group C [(23.61±4.20)HU](F=2.05,P=0.03). The signal to noise ratio of aortic root in group A (18.61±5.28) was significantly better than that in group C (14.75±2.58) (F=5.31,P=0.02). No other significant difference in quantitative image quality were found among the three groups (all P >0.05). Subjective image quality in group A(Z=2.91,P=0.004) and B(Z=2.27,P=0.021) were both significantly better than that in group C. Conclusion  The ultra-low tube voltage (70 kV) combined with ultra-low CM CCTA protocol on third-generation high-pitch DSCT may be better for patients with BMI<28 kg/m2 than those with BMI ≥28 kg/m(2) in China.

  20. 双源计算机断层扫描在永存动脉干诊断中的应用%Clinical application of dual-source CT in diagnosis of persistent truncus arteriosus

    Institute of Scientific and Technical Information of China (English)

    冯越; 刘铁; 翟利浩

    2012-01-01

    Objectives To explore the clinical values of dual - source computed tomography ( CT) in diagnosis of persistent truncus arteriosus(PTA). Methods Seven patients (aged 7 days to 8 years, middle age 3.4 years) diagnosed as PTA by echocardiography underwent cardiac CT with dual-source CT machine. Two- and three-dimensional images were reformated by multiple planar reformation (coronal, sagital and oblique), maximum intensity projection and volume rendering. Of the 7 patients, 4 underwent angiocardiography. Results Qualitative and classification diagnosis were made through Dual-source CT in all the 7 cases. Dual-source CT visualized 28 concomitant anomalies while echocardiography visualized 24 in all the 7 cases. Conclusions Qualitalive and classification diagnosis can be made through Dual-source CT which contributes to the strategies and improvement of operations.%目的 探讨双源计算机断层扫面(computed tomography,CT)在永存动脉干诊断中的应用价值.方法 选择7例经超声心动图诊断为永存动脉干患者,年龄7d~8岁,中位年龄3.4岁.采用双源CT,心电门控下对比增强完成心脏检查,并在图像工作站完成多平面(MPR)、最大密度投影(MIP)和三维容积漫游(VR)处理.其中有4例进行心导管检查.结果 双源CT对7例永存动脉干均作出定性诊断和分型诊断,共发现合并畸形28处.超声心动图共显示24处.结论 双源CT可以对永存动脉干患者作出准确诊断及分型,并有助于临床手术方案的制订与完善.

  1. Quantification of left coronary bifurcation angles and plaques by coronary computed tomography angiography for prediction of significant coronary stenosis: A preliminary study with dual-source CT

    Science.gov (United States)

    Cui, Yue; Zeng, Wenjuan; Yu, Jie; Lu, Jing; Hu, Yuannan; Diao, Nan; Liang, Bo; Han, Ping; Shi, Heshui

    2017-01-01

    Purpose To evaluate the diagnostic performance of left coronary bifurcation angles and plaque characteristics for prediction of coronary stenosis by dual-source CT. Methods 106 patients suspected of coronary artery disease undergoing both coronary computed tomography angiography (CCTA) and invasive coronary angiography (CAG) within three months were included. Left coronary bifurcation angles including the angles between the left anterior descending artery and left circumflex artery (LAD-LCx), left main coronary artery and left anterior descending artery (LM-LAD), left main coronary artery and left circumflex artery (LM-LCx) were measured on CT images. CCTA plaque parameters were calculated by plaque analysis software. Coronary stenosis ≥ 50% by CAG was defined as significant. Results 106 patients with 318 left coronary bifurcation angles and 126 vessels were analyzed. The bifurcation angle of LAD-LCx was significantly larger in left coronary stenosis ≥ 50% than stenosis coronary stenosis (OR = 1.423, P = 0.002). In ROC curve analysis, LAD-LCx predicted significant left coronary stenosis with a sensitivity of 66.7%, specificity of 78.4%, positive predictive value of 85.2% and negative predictive value of 55.8%. The lipid plaque volume improved the diagnostic performance of CCTA diameter stenosis (AUC: 0.854 vs. 0.900, P = 0.045) in significant coronary stenosis. Conclusions The bifurcation angle of LAD-LCx could predict significant left coronary stenosis. Wider LAD-LCx is related to non-calcified lesions. Lipid plaque volume could improve the diagnostic performance of CCTA for coronary stenosis prediction. PMID:28346530

  2. Radiation exposure and image quality in staged low-dose protocols for coronary dual-source CT angiography: a randomized comparison

    Energy Technology Data Exchange (ETDEWEB)

    Pflederer, Tobias; Jakstat, Josy; Marwan, Mohamed; Schepis, Tiziano; Bachmann, Sven; Muschiol, Gerd; Ropers, Dieter; Daniel, Werner G.; Achenbach, Stephan [University of Erlangen, Department of Internal Medicine 2, Erlangen (Germany); Kuettner, Axel; Anders, Katharina; Lell, Michael [University of Erlangen, Institute of Diagnostic Radiology, Erlangen (Germany)

    2010-05-15

    To evaluate staged low-dose approaches for coronary CT angiography (CTA) in which a standard sequence was added if the low-dose sequence did not allow reliable rule-out of coronary stenosis. A total of 176 consecutive patients referred for dual-source CTA were randomized to three protocols: group 1 using prospective ECG-triggering (100 kV, 330 mAs), group 2 a retrospectively gated ''MinDose'' sequence (100 kV, 330 mAs) and group 3 a standard spiral sequence (120 kV, 400 mAs). If image quality in low-dose groups 1 or 2 was non-diagnostic, an additional standard CT examination (as in group 3) was performed. Non-diagnostic image quality was found in 11/56, 4/55, and 2/65 patients (46/896, 4/880 and 3/1,040 coronary segments) in groups 1, 2 and 3, respectively. Median (interquartile ranges) volumes of contrast material, CTDI{sub vol}, DLP and effective dose for low-dose groups 1 and 2 and for standard group 3 were 92.5 (11.3), 75.0 (2.5) and 75.0 (9.0) ml; 8.0 (1.4), 16.8 (4.8) and 48.1 (14.2) mGy; 108.0 (27.3), 246.0 (93.0) and 701.0 (207.8) mGy cm; and 1.5 (0.4), 3.4 (1.3) and 9.8 (2.9) mSv, respectively. A staged coronary CTA protocol with an initial low-dose approach and addition of a standard sequence - should image quality be too low - can lead to a substantial reduction in radiation exposure. (orig.)

  3. Application Progress of Dual-source CT and Craniocervical CTA%双源CT头颈部CTA的应用进展

    Institute of Scientific and Technical Information of China (English)

    金欣; 韩淑祯; 张晓光

    2014-01-01

    目前双源CT是当今世界上最先进的CT设备,头颈部CTA作为一种无创性检查方法对头颈动脉血管狭窄及斑块的诊断有重要价值和帮助,其优点为检查时间短、成功率高、费用相对低廉、并发症少、安全无创等,可以作为头颈部动脉血管检查的首选和重要方法。头颈部血管病变是脑血管疾病的主要发病原因之一,尽早发现头颈部动脉病变,通过发现“罪犯血管”进行及时干预治疗和二级预防,可显著降低脑血管疾病的发病率、致残率、死亡率。%Dual-source CT is currently the most advanced CT equipment in the world. Craniocervical CTA as a noninvasive method, has significant value and assistance for the diagnosis of head and neck artery stenosis and plaque, its advantages including short time, high success rate, relatively low cost, fewer complications, safety and noninvasiveness, and can serve as a preferred and important method for head and neck arteries inspection. Craniocervical vascular disease is one of the major causes of cerebrovascular diseases, early detection of head and neck artery disease, finding“culprit vessels”and timely carrying out intervention treatment and secondary prevention, can significantly reduce the incidence of cerebrovascular diseases.

  4. Study of new dual-source dual-energy CT pulmonary angiography for pulmonary embolism diagnosis%第二代双源CT双能量成像对肺栓塞的诊断价值研究

    Institute of Scientific and Technical Information of China (English)

    吴山; 武志峰; 鄂林宁; 江小鹏

    2012-01-01

    目的:探讨西门子第二代双源CT(Somatom Definition Flash)双能量成像对肺动脉栓塞的诊断价值.方法:回顾性研究42位临床疑诊肺栓塞行双能量肺血管成像(DE-CTPA)扫描的患者的资料,利用工作站双能量软件Lung PBV(肺灌注)、Lung Vessels(肺血管)进行彩色编码成像.2名胸部影像医师结合DE-CTPA与软件提供的信息做出诊断.结果:根据临床及CT结果,其中32例(76.2%,32/42)存在肺动脉栓塞,28例在CTPA上表现为肺动脉充盈缺损,4例在CTPA上未见异常征象,而双能量成像上表现为亚段或以下水平灌注或充盈缺损.双能量Lung PBV测得32例48个栓塞肺区CT强化值(35.6±12.1)HU,低于非栓塞区域所测得的CT强化值(44.5±10.6) HU,t=-2.336,P=0.027.结论:双能量Lung PBV与Lung Vessels软件能显示肺栓塞所致的灌注及充盈缺损,结合CTPA能提高肺栓塞的检出率,特别是外周性肺动脉栓塞.%Objective: To investigate the diagnostic value of the second-generation Siemens dual-source CT(Somatom Definition Flash) dual-energy imaging of pulmonary embolism. Methods: Dual-energy pulmonary angiography (CTPA) data of 42 patients with clinically suspected pulmonary embolism were retrospectively studied by dual—energy software on the workstation. Lung PBV (lung perfusion), Lung Vessels (pulmonary vasculature) and color-coded imaging were analyzed. Two chest-imaging physicians combined information provided by both the DE-CTPA and software to make a diagnosis. Results: According to clinical and CT findings, 32 cases(76.2%, 32/42) had pulmonary embolism, with pulmonary filling defects on CTPA in 28 cases, normal CTPA but perfusion defects in sub-segments or below on DE-CTPA in four cases. Lung PBV measured 32 cases with 48 embolism pulmonary, with a CT enhancement value of (35.6+12.1) HU, lower than the non-embolism region with a CT enhancement value of (44.5±10.6) HU(t=-2.336, P=0.027). Conclusion: Dual-energy lung perfusion(Lung PBV

  5. Low-dose prospective ECG-triggering dual-source CT angiography in infants and children with complex congenital heart disease: first experience

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Zhaoping; Wang, Ximing; Duan, Yanhua; Wu, Lebin; Wu, Dawei; Chao, Baoting; Liu, Cheng; Xu, Zhuodong [Shandong University, Shandong Medical Imaging Research Institute, Jinan, Shandong (China); Li, Hongxin; Liang, Fei [Shandong Provincial Hospital, Department of Cardiovascular Surgery, Jinan, Shandong (China); Xu, Jian; Chen, Jiuhong [Siemens. Ltd. China, CT Research Collaboration, Beijing (China)

    2010-10-15

    To explore the clinical value of low-dose prospective ECG-triggering dual-source CT (DSCT) angiography in infants and children with complex congenital heart disease (CHD) compared with transthoracic echocardiography (TTE). Thirty-five patients (mean age: 16 months, range: 2 months to 6 years; male 15; mean weight: 12 kg) underwent low-dose prospective ECG-triggering DSCT angiography and TTE. Surgeries were performed in 29 patients, and conventional cardiac angiography (CCA) was performed in 8 patients. The accuracy was calculated based on the surgical and/or CCA findings. The overall imaging quality was evaluated on a five-point scale. A total of 146 separate cardiovascular deformities were confirmed. DSCT missed three atrial septal defects and a patent ductus arteriosus. The accuracy of DSCT angiography and TTE was 97.3% (142/146) and 92.5% (135/146), respectively. Overall test parameters for DSCT angiography and TTE were similar (sensitivity, 97.3% vs 92.5%; specificity, 99.8% vs 99.8%). The average subjective image quality score was 4.3 {+-} 0.7. The mean effective dose was 0.38 {+-} 0.09 mSv. Prospective ECG-triggering DSCT angiography with a very low effective radiation dose allows the accurate diagnosis of anomalies in infants and children with complex CHD compared with TTE. It has great promise to become a commonly used second-line technique for complex CHD. (orig.)

  6. Diagnostic accuracy of coronary CT angiography using 3{sup rd}-generation dual-source CT and automated tube voltage selection: Clinical application in a non-obese and obese patient population

    Energy Technology Data Exchange (ETDEWEB)

    Mangold, Stefanie [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Eberhard-Karls University Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany); Wichmann, Julian L. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Schoepf, U.J. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Medical University of South Carolina, Division of Cardiology, Department of Medicine, Charleston, SC (United States); Caruso, Damiano [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); University of Rome ' ' Sapienza' ' , Department of Radiological Sciences, Oncology and Pathology, Rome (Italy); Tesche, Christian [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Heart Centre Munich-Bogenhausen, Department of Cardiology, Munich (Germany); Steinberg, Daniel H.; Bayer, Richard R. [Medical University of South Carolina, Division of Cardiology, Department of Medicine, Charleston, SC (United States); Varga-Szemes, Akos; Stubenrauch, Andrew C.; Biancalana, Matthew; De Cecco, Carlo N. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Nikolaou, Konstantin [Eberhard-Karls University Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany)

    2017-06-15

    To investigate diagnostic accuracy of 3{sup rd}-generation dual-source CT (DSCT) coronary angiography in obese and non-obese patients. We retrospectively analyzed 76 patients who underwent coronary CT angiography (CCTA) and invasive coronary angiography. Prospectively ECG-triggered acquisition was performed with automated tube voltage selection (ATVS). Patients were dichotomized based on body mass index in groups A (<30 kg/m{sup 2}, n = 37) and B (≥30 kg/m{sup 2}, n = 39) and based on tube voltage in groups C (<120 kV, n = 46) and D (120 kV, n = 30). Coronary arteries were assessed for significant stenoses (≥50 % luminal narrowing) and diagnostic accuracy was calculated. Per-patient overall sensitivity, specificity, positive predictive value, negative predictive value (NPV) and accuracy were 96.9 %, 95.5 %, 93.9 %, 97.7 % and 96.1 %, respectively. Sensitivity and NPV were lower in groups B and D compared to groups A and C, but no statistically significant differences were observed (group A vs. B: sensitivity, 100.0 % vs. 93.3 %, p = 0.9493; NPV, 100 % vs. 95.5 %, p = 0.9812; group C vs. D: sensitivity, 100.0 % vs. 92.3 %, p = 0.8462; NPV, 100.0 % vs. 94.1 %, p = 0.8285). CCTA using 3{sup rd}-generation DSCT and (ATVS) provides high diagnostic accuracy in both non-obese and obese patients. (orig.)

  7. The Application of Dual source CT and Dual Energy Imaging to the Diagnosis of Pulmonary Embolism%双源CT双能量成像在肺动脉栓塞诊断中的应用

    Institute of Scientific and Technical Information of China (English)

    彭可雨; 阮兵; 梁汉欢; 张洪; 梁艳

    2016-01-01

    Objective To study the value of dual energy pulmonary angiography (DECTPA) with dual-source CT (DSCT) in pulmonary embolism (PE).Methods Collected the clinical data of 26 patients suspected of PE in our hospital underwent DECTPA with DSCT. Assessed the value of dual energy pulmonary angiography (DECTPA) with dual-source CT (DSCT) in pulmonary embolism (PE).Results The 96.30%, 90.57% agreement between DEPI and CTPA were showed in the levels of lung and partial lung respectively. Complete filling defects of segmental and subsegmental pulmonary arteries mostly showed correspon dence perfusion defects in the CT perfusion map. However, when there were partial filling defects, most of them were partial perfusion defects. A few of them were normal in the CT perfusion map. With CTPA as a reference standard,in the level of lung, the results show that compared with DEPI, the sensitivity was 96.30% (52/54), specificity of 100% (76/76).Conclusion There was moderate agreement between the judgement of CTPA and DEPI. The perfusion defects in the DEPI related to the degree and location of the filling defects in the CTP A. The combination of CTPA and DEPI will offer more information for diagnosis of the pulmonary embolism. It is worth promotion in the clinical.%目的:探讨双源CT双能量成像在肺动脉栓塞诊断中的应用价值。方法收集在我院使用双源CT双能量肺动脉成像检查的26例临床资料进行分析,探讨双源CT双能量肺动脉成像(DEPI)在肺动脉栓塞中的应用价值。结果在肺叶基础上,DEPI与CTPA检出血管栓塞的符合率为96.30%;在肺段的基础上,DEPI与CTPA检出血管栓塞的符合率为90.57%。当段、亚段肺动脉栓塞充盈缺损完全时,DEPI表现为肺段或亚段分布灌注缺损,当部分充盈缺损时,DEPI以灌注降低为主,少数表现为无灌注缺损;利用DEPI诊断PE的敏感性96.30%(52/54),特异性100%。结论 DEPI表现与CTPA肺动脉栓塞程度、部位有

  8. Ultra-low-dose dual-source CT coronary angiography with high pitch: diagnostic yield of a volumetric planning scan and effects on dose reduction and imaging strategy

    Science.gov (United States)

    Hamm, B; Huppertz, A; Lembcke, A

    2015-01-01

    Objective: To evaluate the role of an ultra-low-dose dual-source CT coronary angiography (CTCA) scan with high pitch for delimiting the range of the subsequent standard CTCA scan. Methods: 30 patients with an indication for CTCA were prospectively examined using a two-scan dual-source CTCA protocol (2.0 × 64.0 × 0.6 mm; pitch, 3.4; rotation time of 280 ms; 100 kV): Scan 1 was acquired with one-fifth of the tube current suggested by the automatic exposure control software [CareDose 4D™ (Siemens Healthcare, Erlangen, Germany) using 100 kV and 370 mAs as a reference] with the scan length from the tracheal bifurcation to the diaphragmatic border. Scan 2 was acquired with standard tube current extending with reduced scan length based on Scan 1. Nine central coronary artery segments were analysed qualitatively on both scans. Results: Scan 2 (105.1 ± 10.1 mm) was significantly shorter than Scan 1 (127.0 ± 8.7 mm). Image quality scores were significantly better for Scan 2. However, in 5 of 6 (83%) patients with stenotic coronary artery disease, a stenosis was already detected in Scan 1 and in 13 of 24 (54%) patients with non-stenotic coronary arteries, a stenosis was already excluded by Scan 1. Using Scan 2 as reference, the positive- and negative-predictive value of Scan 1 was 83% (5 of 6 patients) and 100% (13 of 13 patients), respectively. Conclusion: An ultra-low-dose CTCA planning scan enables a reliable scan length reduction of the following standard CTCA scan and allows for correct diagnosis in a substantial proportion of patients. Advances in knowledge: Further dose reductions are possible owing to a change in the individual patient's imaging strategy as a prior ultra-low-dose CTCA scan may already rule out the presence of a stenosis or may lead to a direct transferal to an invasive catheter procedure. PMID:25710210

  9. 急性主动脉夹层诊断中双源CT检查的应用价值评述%Comment on the Application Value of Dual Source CT in Diagnosis of Acute Aortic Dissection

    Institute of Scientific and Technical Information of China (English)

    陈说

    2015-01-01

    目的:探析双源CT检查在急性主动脉夹层诊断中的运用价值。方法选择120例急性主动脉夹层患者为研究对象,回顾性分析其临床资料。结果双源CT诊断急性主动脉夹层的特异度和敏感度均为100%;同时MPR与VR和MIP在综合显示能力方面比较差异有统计学意义(P<0.05)。结论双源CT诊断急性主动脉夹层具有较高的准确率。%Objective To explore dual-source CT examination in the diagnosis of acute aortic dissection using value. Methods 120 cases of patients with acute aortic dissection were chosen as the research object, the clinical data were retrospectively analyzed. Results The degree of dual-source CT in the diagnosis of acute aortic dissection of the specific and sensitivity was 100%, meanwhile MPR and VR and MIP in the aspect of the comprehensive ability was statistically signiifcant (P<0.05). Conclusion Dual-source CT in the diagnosis of acute aortic dissection has higher accuracy.

  10. 双源CT对主动脉病变的诊断价值%Diagnostic Value of Dual Source CT Angiography in Aortic Disease

    Institute of Scientific and Technical Information of China (English)

    朱建国; 郭亮

    2015-01-01

    Objective To explore the value of the dual-source CT angiography (DSCT) in diagnosis of aortic disease. Methods 90 patients were suspected aortic disease with CTA, raw data were dealt with multiplanar reformation (MPR), curved planar reformation (CPR), maximum intensity projection (MIP) and volume rendering (VR). Results The aortic disease in 90 cases included aortic dissection 27 cases, aortic aneurysm 14 cases, takayasu arteritis 3 cases, atherosclerotic 15 cases, aortic ulcer 5 cases, aortic intramural hematoma 5 cases, aortic coarctation 1 case, aortic variations 1 case, portal spongy degeneration 1 case, Budd-Chiari Syndrome 1 case, superior mesenteric arterial thrombosis 2 cases, portal thrombosis 1 case, left renal artery aneurysms 1 case, splenic artery aneurysms 1 case, pulmonary embolism 4 cases, renal cancer 1 case, normal aortic 7 cases. All the image quality is excellent, and the average effective radiation dose was 3.14 mSv. Conclusion Dual-source CT angiography is significant in diagnosing aortic disease, and can reduce radiation dose.%目的:探讨双源CT扫描血管成像对主动脉病变的诊断价值。方法对临床可疑主动脉病变的90例患者采用双源CT血管造影(CTA)检查,并对原始数据采用多平面重建(MPR)、曲面重建(CPR)、最大密度投影(MIP)和容积再现(VR)后处理技术进行重建。结果90例患者中共检出主动脉夹层27例,主动脉瘤14例,大动脉炎3例,主动脉粥样硬化15例,主动脉壁溃疡5例,主动脉壁内血肿5例,主动脉缩窄1例,主动脉变异1例,门静脉海绵样变性1例,布加氏综合征1例,肠系膜上动脉血栓2例,门静脉血栓1例,左肾动脉瘤1例,脾动脉瘤1例,肺动脉血栓4例,肾癌1例,正常7例。所有图像质量优良,有效射线剂量平均约3.14 mSv。结论双源CT扫描对主动脉病变的诊断具有重要意义,并能降低辐射剂量。

  11. Diagnostic accuracy and its affecting factors of dual-source CT for assessment of coronary stents patency and in-stent restenosis

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xing-hua; YANG Li; WU Jian; JU Hai-yue; ZHANG Fan; HE Bin; CHEN Yun-dai

    2012-01-01

    Background In-stent restenosis is a common complication after stent implantation.However,the assessment of stent lumen in computed tomography (CT) coronary angiography is limited by multiple factors.Our study aimed to evaluate the accuracy and the suspected affecting factors in diagnosing coronary in-stent restenosis by dual-source CT (DSCT) compared with coronary angiography.Methods One hundred and fifteen stents in 50 patients were evaluated with DSCT before coronary angiography for the detection of coronary in-stent restenosis (≥ 50% luminal narrowing).Patency of each stent was analyzed by two independent expert radiologists blinded to the results of coronary angiography.The relationship between diagnostic accuracy and the suspected factors including age,body mass index (BMI),heart rate,variation of heart rate,radiation dose,image quality,location and stent characteristics (type,material,diameter,length and strut thickness) was assessed wilh both univariate and multivariate analysis.The fitting of a Logistic regression model was evaluated using a receiver operating characteristic (ROC) curve.Results Mean stent diameter was (2.9±0.4) mm.Sensitivity,specificity,positive and negative predictive values and accuracy of DSCT in detection of in-stent restenosis were 69.2%,91.2%,50.0%,95.9%,and 88.7%,respectively.In a subgroup of stents with a diameter ≥3.0 mm,sensitivity,specificity,positive and negative predictive values and accuracy were 100.0%,96.5%,75.0%,100.0%+ and 96.8%,respectively.Stent diameter <3.0 mm and poor image quality were associated with poor diagnostic accuracy (P <0.05).The area under curve of ROC was 0.79.Conclusion DSCT can provide high accuracy for the assessment of in-stent restenosis in stents with a diameter ≥3.0mm,and can play an important role in ruling out in-stent restenosis.

  12. Image quality and radiation dose of 128-slice dual-source CT venography using low kilovoltage combined with high-pitch scanning and automatic tube current modulation.

    Science.gov (United States)

    Park, Chan Kue; Choo, Ki Seok; Jeon, Ung Bae; Baik, Seung Kug; Kim, Yong Woo; Kim, Tae Un; Kim, Chang Won; Jeong, Yeon Ju; Jeong, Dong Wook; Lim, Soo Jin

    2013-06-01

    To compare vascular enhancement, image quality, and radiation dose of 128-slice dual-source CT venography (CTV) between an imaging setting of 120 kVp with low pitch, and a setting of 100 kVp combined with high pitch and automatic tube current modulation. A total of 100 patients with suspected deep vein thrombosis and varicose veins were divided into two groups: Group 1 [50 patients, 120 kVp, low pitch (0.6), and fixed 120 mA) and Group 2 (50 patients, 100 kVp, high pitch (3.0), and automatic tube current modulation]. Two radiologists, who were blinded to the image protocol, assessed vascular enhancement and image noise in the inferior vena cava (IVC), femoral vein, and popliteal vein. They also assigned an image quality score independently using a 5-point visual scale. Effective dose was estimated using the dose-length product (DLP). Group demographics, radiation dose, vascular enhancement, image noise, and image quality in the two groups were analyzed. Mean vascular enhancement of the IVC, femoral vein, and popliteal vein was significantly higher in group 2 than in group 1, and images in group 2 had significantly higher image noise. However, there were no significant differences in subjective image quality score of the IVC, femoral vein, and popliteal vein. The mean DLP in group 2 (402.10 ± 94.29 mGy cm) was significantly lower than that in group 1 (973.36 ± 63.20 mGy cm) (P enhancement with acceptable image quality and low radiation dose.

  13. Dual-energy perfusion-CT of pancreatic adenocarcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Klauß, M., E-mail: miriam.klauss@med.uni-heidelberg.de [University of Heidelberg, Dpt. of Diagnostic and Interventional Radiology, Im Neuenheimer Feld 110, 69120 Heidelberg (Germany); Stiller, W., E-mail: wolfram.stiller@med.uni-heidelberg.de [University of Heidelberg, Dpt. of Diagnostic and Interventional Radiology, Im Neuenheimer Feld 110, 69120 Heidelberg (Germany); Pahn, G., E-mail: gregor.pahn@med.uni-heidelberg.de [University of Heidelberg, Dpt. of Diagnostic and Interventional Radiology, Im Neuenheimer Feld 110, 69120 Heidelberg (Germany); Fritz, F., E-mail: franzi.fritz@cegug.org [University of Heidelberg, Dpt. of Diagnostic and Interventional Radiology, Im Neuenheimer Feld 110, 69120 Heidelberg (Germany); Kieser, M., E-mail: meinhard.kieser@med.uni-heidelberg.de [University of Heidelberg, Inst. of Medical Biometry and Informatics, Im Neuenheimer Feld 305, 69120 Heidelberg (Germany); Werner, J., E-mail: jens.werner@med.uni-heidelberg.de [University of Heidelberg, Dpt. of Surgery, Im Neuenheimer Feld 110, 69120 Heidelberg (Germany); Kauczor, H.U., E-mail: hans-ulrich.kauczor@med.uni-heidelberg.de [University of Heidelberg, Dpt. of Diagnostic and Interventional Radiology, Im Neuenheimer Feld 110, 69120 Heidelberg (Germany); Grenacher, L., E-mail: lars.grenacher@med.uni-heidelberg.de [University of Heidelberg, Dpt. of Diagnostic and Interventional Radiology, Im Neuenheimer Feld 110, 69120 Heidelberg (Germany)

    2013-02-15

    Purpose: To evaluate the feasibility of dual-energy CT (DECT)-perfusion of pancreatic carcinomas for assessing the differences in perfusion, permeability and blood volume of healthy pancreatic tissue and histopathologically confirmed solid pancreatic carcinoma. Materials and methods: 24 patients with histologically proven pancreatic carcinoma were examined prospectively with a 64-slice dual source CT using a dynamic sequence of 34 dual-energy (DE) acquisitions every 1.5 s (80 ml of iodinated contrast material, 370 mg/ml, flow rate 5 ml/s). 80 kV{sub p}, 140 kV{sub p}, and weighted average (linearly blended M0.3) 120 kV{sub p}-equivalent dual-energy perfusion image data sets were evaluated with a body-perfusion CT tool (Body-PCT, Siemens Medical Solutions, Erlangen, Germany) for estimating perfusion, permeability, and blood volume values. Color-coded parameter maps were generated. Results: In all 24 patients dual-energy CT-perfusion was. All carcinomas could be identified in the color-coded perfusion maps. Calculated perfusion, permeability and blood volume values were significantly lower in pancreatic carcinomas compared to healthy pancreatic tissue. Weighted average 120 kV{sub p}-equivalent perfusion-, permeability- and blood volume-values determined from DE image data were 0.27 ± 0.04 min{sup −1} vs. 0.91 ± 0.04 min{sup −1} (p < 0.0001), 0.5 ± 0.07 *0.5 min{sup −1} vs. 0.67 ± 0.05 *0.5 min{sup −1} (p = 0.06) and 0.49 ± 0.07 min{sup −1} vs. 1.28 ± 0.11 min{sup −1} (p < 0.0001). Compared with 80 and 140 kV{sub p} the standard deviations of the kV{sub p}120 kV{sub p}-equivalent values were manifestly smaller. Conclusion: Dual-energy CT-perfusion of the pancreas is feasible. The use of DECT improves the accuracy of CT-perfusion of the pancreas by fully exploiting the advantages of enhanced iodine contrast at 80 kV{sub p} in combination with the noise reduction at 140 kV{sub p}. Therefore using dual-energy perfusion data could improve the delineation

  14. Clinical Value of Dual Source CT in the Diagnosis of Coronary Artery Stenosis%双源CT诊断不同程度冠状动脉狭窄的临床价值

    Institute of Scientific and Technical Information of China (English)

    高振兴; 佟晖

    2015-01-01

    Objective To investigate the clinical value of dual source CT in the diagnosis of coronary artery stenosis.MethodsThirty-six patients with clinicaly suspected coronary heart disease in our hospital received with dual source CT and conventional coronary angiography.Results Dual source CT findings and coronary angiography results were compared and the diagnosis of coronary artery stenosis sensitivity for 94.7%,specificity of diagnosis of 95.5%,the positive predictive value for 83.4%,the negative predictive value was 98.78%. The diagnostic accuracy rate was 95.3%. Dual source CT in the diagnosis of severe stenosis diagnostic sensitivity was significantly lower than that of mild stenosis,moderate stenosis diagnosis sensitivity, he difference had statistical significance(P< 0.05).Conclusion With the traditional coronary artery stenosis diagnosis coronary angiography were compared with and dual source CT scan with rapid scanning,high accuracy in the diagnosis and noninvasive clinical advantage.%目的:探讨双源CT诊断不同程度冠状动脉狭窄的临床价值。方法选取来我院因临床拟诊冠心病而接受双源CT和传统冠状动脉造影检查的患者36例。结果双源CT检查结果与冠状动脉造影检查结果相比,其冠状动脉狭窄诊断的敏感度为94.7%、诊断特异性为95.5%、阳性预测值为83.4%、阴性预测值为98.78%,诊断准确率为95.3%。双源CT检查对重度狭窄诊断敏感度低于轻度狭窄和中度狭窄的诊断敏感度,比较差异具有统计学意义(P<0.05)。结论与传统冠状动脉狭窄诊断方式冠状动脉造影相比,双源CT扫描具有扫描迅速、诊断准确率较高,无创伤等临床优势。

  15. Myocardial perfusion imaging with dual energy CT.

    Science.gov (United States)

    Jin, Kwang Nam; De Cecco, Carlo N; Caruso, Damiano; Tesche, Christian; Spandorfer, Adam; Varga-Szemes, Akos; Schoepf, U Joseph

    2016-10-01

    Dual-energy CT (DECT) enables simultaneous use of two different tube voltages, thus different x-ray absorption characteristics are acquired in the same anatomic location with two different X-ray spectra. The various DECT techniques allow material decomposition and mapping of the iodine distribution within the myocardium. Static dual-energy myocardial perfusion imaging (sCTMPI) using pharmacological stress agents demonstrate myocardial ischemia by single snapshot images of myocardial iodine distribution. sCTMPI gives incremental values to coronary artery stenosis detected on coronary CT angiography (CCTA) by showing consequent reversible or fixed myocardial perfusion defects. The comprehensive acquisition of CCTA and sCTMPI offers extensive morphological and functional evaluation of coronary artery disease. Recent studies have revealed that dual-energy sCTMPI shows promising diagnostic accuracy for the detection of hemodynamically significant coronary artery disease compared to single-photon emission computed tomography, invasive coronary angiography, and cardiac MRI. The aim of this review is to present currently available DECT techniques for static myocardial perfusion imaging and recent clinical applications and ongoing investigations.

  16. Prospectively ECG-triggered high-pitch coronary angiography with third-generation dual-source CT at 70 kVp tube voltage: feasibility, image quality, radiation dose, and effect of iterative reconstruction.

    Science.gov (United States)

    Hell, Michaela M; Bittner, Daniel; Schuhbaeck, Annika; Muschiol, Gerd; Brand, Michael; Lell, Michael; Uder, Michael; Achenbach, Stephan; Marwan, Mohamed

    2014-01-01

    Low tube voltage reduces radiation exposure in coronary CT angiography (CTA). Using 70 kVp tube potential has so far not been possible because CT systems were unable to provide sufficiently high tube current with low voltage. We evaluated feasibility, image quality (IQ), and radiation dose of coronary CTA using a third-generation dual-source CT system capable of producing 450 mAs tube current at 70 kVp tube voltage. Coronary CTA was performed in 26 consecutive patients with suspected coronary artery disease, selected for body weight Image noise was lower in IR vs FBP (60 ± 10 HU vs 74 ± 8 HU; P < .001). In patients <100 kg and with a regular heart rate <60 beats/min, third-generation dual-source CT using high-pitch spiral acquisition and 70 kVp tube voltage is feasible and provides both robust IQ and very low radiation exposure. Copyright © 2014 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

  17. 双源 CT 软件对肺栓塞诊断的应用%Study of the diagnosis and clinical application of pulmonary embolism with dual source CT software

    Institute of Scientific and Technical Information of China (English)

    朱建国; 郭亮

    2014-01-01

    Objective:To investigate the value of dual source CT software in the diagnosis and clinical application of pulmonary artery embolism (PE).Methods:Sixty-six consecutive patients having suspected PE underwent CT pulmonary angiography with dual-energy technique on a dual source CT scanner.All raw data were transported to the workstation,CT pulmonary angiography (CTPA)images,Lung perfusion blood volume (PBV)images,and Lung Vessels (LV)images were obtained after post-processing.The consistency of CTPA images with LV images in any parts of lung in every normal sub-jects were analyzed and examined by Kappa test.Then sensitivity and specificity of CTPA,lung PBV images,LV images, Lung PBV+LV images in the diagnosis of PE and the positive predictive value (PPV)and negative predictive value (NPV) were calculated respectively.χ2-test or exact probability test were applied to compare the accurate diagnosis rate in detecting PE in different positions of pulmonary artery.Results:CTPA images and LV images had a good consistency in showing the pulmonary arteries of 32 normal subjects in total (K=0.71,P <0.05).Of the 4 software used,the sensitivity of LV soft-ware and Lung PBV+LV was the highest (100%),yet false positive was existed,the PPV was 94.4%、97.1% respective-ly,the specificity of CTPA was the highest (100%),the specificity of Lung PBV software and LV software was 53.8%, 84.6% respectively.Software including CTPA、LV、Lung PBV+ LV in detecting embolisms in pulmonary artery trunks were completely in consistency,no statistic difference was existed in the diagnosis of PE in lobar and segmental pulmonary arteries.However,significant statistical difference was showed in sub-segment or lower pulmonary arteries (χ2 =7.58,P <0.05).As a whole,significant statistical difference was existed in the diagnosis of PE by these three software (χ2 =6.22, P <0.05).Conclusion:Dual source CT with CTPA images and LV images showed a good consistency in displaying pulmo-nary arteries

  18. Dual energy CT: New horizon in medical imaging

    Energy Technology Data Exchange (ETDEWEB)

    Goo, Hyun Woo [Dept. of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Goo, Jin Mo [Dept. of Radiology, Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2017-08-01

    Dual-energy CT has remained underutilized over the past decade probably due to a cumbersome workflow issue and current technical limitations. Clinical radiologists should be made aware of the potential clinical benefits of dual-energy CT over single-energy CT. To accomplish this aim, the basic principle, current acquisition methods with advantages and disadvantages, and various material-specific imaging methods as clinical applications of dual-energy CT should be addressed in detail. Current dual-energy CT acquisition methods include dual tubes with or without beam filtration, rapid voltage switching, dual-layer detector, split filter technique, and sequential scanning. Dual-energy material-specific imaging methods include virtual monoenergetic or monochromatic imaging, effective atomic number map, virtual non-contrast or unenhanced imaging, virtual non-calcium imaging, iodine map, inhaled xenon map, uric acid imaging, automatic bone removal, and lung vessels analysis. In this review, we focus on dual-energy CT imaging including related issues of radiation exposure to patients, scanning and post-processing options, and potential clinical benefits mainly to improve the understanding of clinical radiologists and thus, expand the clinical use of dual-energy CT; in addition, we briefly describe the current technical limitations of dual-energy CT and the current developments of photon-counting detector.

  19. Dual-Energy CT: New Horizon in Medical Imaging.

    Science.gov (United States)

    Goo, Hyun Woo; Goo, Jin Mo

    2017-01-01

    Dual-energy CT has remained underutilized over the past decade probably due to a cumbersome workflow issue and current technical limitations. Clinical radiologists should be made aware of the potential clinical benefits of dual-energy CT over single-energy CT. To accomplish this aim, the basic principle, current acquisition methods with advantages and disadvantages, and various material-specific imaging methods as clinical applications of dual-energy CT should be addressed in detail. Current dual-energy CT acquisition methods include dual tubes with or without beam filtration, rapid voltage switching, dual-layer detector, split filter technique, and sequential scanning. Dual-energy material-specific imaging methods include virtual monoenergetic or monochromatic imaging, effective atomic number map, virtual non-contrast or unenhanced imaging, virtual non-calcium imaging, iodine map, inhaled xenon map, uric acid imaging, automatic bone removal, and lung vessels analysis. In this review, we focus on dual-energy CT imaging including related issues of radiation exposure to patients, scanning and post-processing options, and potential clinical benefits mainly to improve the understanding of clinical radiologists and thus, expand the clinical use of dual-energy CT; in addition, we briefly describe the current technical limitations of dual-energy CT and the current developments of photon-counting detector.

  20. Clinical utility of ultra high pitch dual source thoracic CT imaging of acute pulmonary embolism in the emergency department: Are we one step closer towards a non-gated triple rule out?

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Daniel J., E-mail: danieljameshou@gmail.com; Tso, David K., E-mail: david.k.tso@gmail.com; Davison, Chris, E-mail: chrisdavison100@gmail.com; Inacio, Joao, E-mail: joao.r.inacio@gmail.com; Louis, Luck J., E-mail: lucklouis@gmail.com; Nicolaou, Savvakis, E-mail: savvas.nicolaou@vch.ca; Reimann, Anja J., E-mail: anja.reimann@gmx.de

    2013-10-01

    Objectives/Purpose: Aim of this study was to retrospectively compare the image quality and the radiation dose of an ultra high pitch CT scan for the evaluation of pulmonary embolism and visualization of cardiac structures in comparison to our institution's standard pulmonary embolism protocol. Method and materials: The study cohort consisted of 115 consecutive patients, 57 underwent CT pulmonary angiography on a dual source 128 slice scanner (Siemens Somatom Definition FLASH) via an ultra high pitch mode (Pitch 2.8) while 58 were scanned on a dual source 64 slice scanner (Siemens Somatom Definition Dual Source) with standard pitch (Pitch 0.9). Qualitative image assessment was determined by two blinded radiologists with 3 and 15 years’ experience in chest and cardiac CT. Quantitative image assessment was determined by the signal to noise ratio (SNR) and contrast to noise ratio (CNR). Effective radiation dose was calculated via the product of the dose length product. Results: For the ultra high pitch protocol, 14% (8/57) were positive for pulmonary embolus compared to 13.7% (8/58) for the standard pitch group. 98.2% of the ultra high pitch scans were diagnostic for pulmonary embolus vs. 94.8% of the standard protocol. Visualization of cardiac structures was significantly improved with the ultra high pitch protocol (p < 0.0001). Significantly more lung parenchymal motion was observed on the standard protocol (p < 0.0001). The mean pulmonary vessel attenuation, SNR, and CNR were not significantly different. The mean effective dose was lower for the ultra high pitch studies (4.09 mSv ± 0.78 vs. 7.72 mSv ± 2.60, p < 0.0001). Conclusion: Ultra high pitch CT imaging for pulmonary embolus is a technique which has potential to assess motion free evaluation of most cardiac structures and proximal coronary arteries at lower radiation doses.

  1. The application value of dual-source dual-energy CT in the diagnosis and pathology grade of esophageal cancer%双源 CT 能谱曲线在食管癌诊断及其病理分级中的应用价值

    Institute of Scientific and Technical Information of China (English)

    刘小静; 苗重昌; 周胜利

    2016-01-01

    目的:探讨双源 CT 能谱曲线在食管癌诊断及其病理分级中的应用价值。方法60例经内镜或病理证实的食管癌患者行双源双能量模式扫描,两个球管管电压分别为:A 球管100 kV,B 球管140 kV,双能量扫描时两组球管同时工作。将扫描获得的两组数据上传至工作站进行相关后处理及分析:绘制食管癌病灶及正常食管管壁能谱曲线,比较食管癌病灶与正常食管壁、不同分化程度食管癌的能谱曲线特征及其斜率之间的差异与联系。食管癌病理分级依据病理结果。结果①食管癌病灶能谱曲线走行位于正常食管管壁上方,并且斜率高于正常食管壁;②不同分化程度食管癌能谱曲线走行及趋势不同,分化程度越差,曲线走行越靠上,对各组能谱曲线斜率比较可得分化程度越差,能谱曲线斜率越大。结论双源双能量 CT 能谱曲线在食管癌诊断及病理分级中有着一定的临床应用价值。%Objective To explore the application value of spectrum curve dual - energy CT in the diagnosis of esophageal cancer and it′s pathology grade. Methods 60 cases confirmed of esophageal carcinoma by endoscopic or pathology underwent dual source CT dual energy scan mode using two ball tube voltage respectively. Ball tube A was 100 kV,and ball tube B was 140 kV. The two ball tube worked at the same time when the dual energy scan was conducted. The data obtained from the dual energy scan was sent to the workstation for post - processing and analy-sis. The spectrum of esophageal carcinoma and normal esophageal wall was drawn,then the differences and relationship of the spectral curve and the slope between esophageal carcinoma and normal esophageal wall,different grades of esophageal cancer were analyzed and compared. The grade of the esophageal cancer was based on the pathology. Results ①The spectral curve of esophageal cancer was located above the normal esophageal

  2. Radiation dose for thoracic and coronary step-and-shoot CT using a 128-slice dual-source machine in infants and small children with congenital heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Jean-Francois; Rohnean, Adela; Elfassy, Eric; Sigal-Cinqualbre, Anne [Radiology-Centre Chirurgical Marie Lannelongue, Plessis-Robinson (France)

    2011-02-15

    For coronary artery visualization, retrospective ECG-gated acquisition by dual-source computed tomography (DSCT) was superior to spiral non-ECG-gated acquisition in a paediatric population of congenital heart disease (CHD) patients. However, retrospective cardiac CT is associated with substantial radiation doses to the patient. Recently, DSCT with end-systolic reconstruction was found to be robust for imaging the coronary arteries in patients with high heart rates. To evaluate step-and-shoot DSCT with end-systolic reconstruction for evaluating the heart, coronary arteries and other thoracic structures in young children with CHD. All neonates and children younger than 6 years of age who were referred to our institution for CHD evaluation between September and October 2009 were included in the study. ECG-gated DSCT was performed in sequential prospective mode centred on the systolic phase identified by ECG analysis. To assess the radiation dose, we recorded the dose-length product (DLP) in mGy.cm and the effective dose in mSv estimated from the DLP. Overall image quality was evaluated using a 5-grade scoring system and was assessed by looking at cardiac and vascular structures. The image quality for the proximal and middle segments of the right and left coronary arteries was also evaluated using a 5-grade scale. Images of diagnostic quality (grade {>=} 3) were obtained in all 30 children with a mean image quality grade of 4.7 {+-} 0.6 (range, 3-5). Mean DLP was 5.7 {+-} 4.8 mGy*cm (range, 1-22 mGy cm) and mean effective radiation dose was 0.26 {+-} 0.16 mSv (range, 0.05-0.8 mSv). Prospective ECG-gated thoracic DSCT at end-systole usually provides adequate thoracic and coronary artery image quality in neonates, infants and young children with CHD, independent of heart rate. This new method is associated with lower radiation doses compared to previous literature (mean effective dose, 0.26 mSv). (orig.)

  3. Triple-rule-out dual-source CT angiography of patients with acute chest pain: Dose reduction potential of 100 kV scanning

    Energy Technology Data Exchange (ETDEWEB)

    Krissak, Radko, E-mail: radko.krissak@umm.de [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany); Henzler, Thomas; Prechel, Anne; Reichert, Miriam [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany); Gruettner, Joachim; Sueselbeck, Tim [1st Department of Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany); Schoenberg, Stefan O.; Fink, Christian [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany)

    2012-12-15

    Purpose: To investigate the dose reduction potential of low kV triple-rule-out dual-source CT angiography (TRO-CTA) in non-obese (BMI ≤ 25 kg/m{sup 2}) patients with acute chest pain. Materials and methods: Sixty consecutive patients were randomly assigned to two different retrospectively ECG-gated TRO-CTA protocols in this prospective trial: Thirty patients were examined with a 120-kV standard protocol (320 reference mAs with automatic tube current modulation, automatically adapted pitch and ECG-pulsing) and served as the control group (group 1), an otherwise identical 100 kV protocol was used in the other thirty patients (group 2) for a radiation dose reduction. Subjective image quality was assessed on a 5 point scale (1: excellent, 5: non-diagnostic) by two blinded observers. Quantitative image analysis assessed vascular attenuation, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) in different vascular segments. The effective dose was calculated from the dose length product (DLP) using a conversion coefficient of 0.017 mSv mGy{sup −1} cm{sup −1}. Results: There was no significant difference of age, BMI, heart rate, pitch or scan length between both patient groups. Subjective image quality was rated similar in both groups (group 1: 1.2 ± 0.4, group 2: average score = 1.3 ± 0.5). Vessel attenuation was significantly higher in group 2 than in group 1 (ascending aorta: 456 ± 83 HU vs. 370 ± 78 HU, p < 0.001; pulmonary artery: 468 ± 118 HU vs. 411 ± 91 HU, p = 0.03; left coronary artery: 437 ± 110 HU vs. 348 ± 89 HU, p < 0.001), however, there was no significant difference in SNR (13.2 ± 7.6 vs. 14.5 ± 7.5, p = 0.49) or CNR (13.8 ± 6.6 vs. 15.9 ± 7.7, p = 0.25). The effective radiation dose of the 100 kV protocol was significantly lower (9.6 ± 3.2 mSv vs. 18.1 ± 9.4 mSv, p < 0.0001). Conclusion: TRO-CTA with 100 kV is feasible in non-obese patients and results in diagnostic image quality and significantly reduced radiation dose.

  4. Accuracy of dual-source CT coronary angiography: first experience in a high pre-test probability population without heart rate control

    Energy Technology Data Exchange (ETDEWEB)

    Scheffel, Hans; Alkadhi, Hatem; Desbiolles, Lotus; Frauenfelder, Thomas; Schertler, Thomas; Husmann, Lars; Marincek, Borut; Leschka, Sebastian [University Hospital Zurich, Institute of Diagnostic Radiology, Zurich (Switzerland); Plass, Andre; Vachenauer, Robert; Grunenfelder, Juerg; Genoni, Michele [Clinic for Cardiovascular Surgery, Zurich (Switzerland); Gaemperli, Oliver; Schepis, Tiziano [University Hospital Zurich, Cardiovascular Center, Zurich (Switzerland); Kaufmann, Philipp A. [University Hospital Zurich, Cardiovascular Center, Zurich (Switzerland); University of Zurich, Center for Integrative Human Physiology, Zurich (Switzerland)

    2006-12-15

    The aim of this study was to assess the diagnostic accuracy of dual-source computed tomography (DSCT) for evaluation of coronary artery disease (CAD) in a population with extensive coronary calcifications without heart rate control. Thirty patients (24 male, 6 female, mean age 63.1{+-}11.3 years) with a high pre-test probability of CAD underwent DSCT coronary angiography and invasive coronary angiography (ICA) within 14{+-}9 days. No beta-blockers were administered prior to the scan. Two readers independently assessed image quality of all coronary segments with a diameter {>=}1.5 mm using a four-point score (1: excellent to 4: not assessable) and qualitatively assessed significant stenoses as narrowing of the luminal diameter >50%. Causes of false-positive (FP) and false-negative (FN) ratings were assigned to calcifications or motion artifacts. ICA was considered the standard of reference. Mean body mass index was 28.3{+-}3.9 kg/m{sup 2} (range 22.4-36.3 kg/m{sup 2}), mean heart rate during CT was 70.3{+-}14.2 bpm (range 47-102 bpm), and mean Agatston score was 821{+-}904 (range 0-3,110). Image quality was diagnostic (scores 1-3) in 98.6% (414/420) of segments (mean image quality score 1.68{+-}0.75); six segments in three patients were considered not assessable (1.4%). DSCT correctly identified 54 of 56 significant coronary stenoses. Severe calcifications accounted for false ratings in nine segments (eight FP/one FN) and motion artifacts in two segments (one FP/one FN). Overall sensitivity, specificity, positive and negative predictive value for evaluating CAD were 96.4, 97.5, 85.7, and 99.4%, respectively. First experience indicates that DSCT coronary angiography provides high diagnostic accuracy for assessment of CAD in a high pre-test probability population with extensive coronary calcifications and without heart rate control. (orig.)

  5. Intravenous Contrast Material Administration at High-pitch Dual-source CT Coronary Angiography: Bolus-tracking Technique with Shortened Time of Respiratory Instruction Versus Test Bolus Technique

    Institute of Scientific and Technical Information of China (English)

    Kai Sun; Guo-rong Liu; Yue-chun Li; Rui-juan Han; Li-fang Cui; Li-jun Ma; Li-gang Li; Chang-yong Li

    2012-01-01

    Objective To investigate the feasibility of acquiring the similar homogeneous enhancement using bolus-tracking techniques with shortened respiratory time in prospectively electrocardiogram-gated high-pitch spiral acquisition mode (Flash mode) coronary computed tomography angiography (CCTA) compared with test bolus technique.Methods One hundred and eighty-four consecutive patients with mean heart rate ≤65 beats per minute undergoing CCTA were prospectively included in this study.The patients were randomly divided into two groups.Patients in the group A (n=92) instructed to shorten respiratory time received CCTA using bolus-tracking technique with high-pitch spiral acquisition mode (Flash mode),while those in the group B (n=92) underwent CCTA with test bolus technique.The attenuation in the ascending aorta,image noise,contrast-to-noise ratio and radiation doses of the two groups were assessed.Results There were no significant differences in the mean attenuation values in the ascending aorta (483.18±59.07 HU vs.498.7±83.51 HU,P=0.183),image noise (21.4±4.5 HU vs.20.9±4.3 HU,P=0.414),contrast-to-noise ratio (12.1±4.2 vs.13.8±5.1,P=0.31) between the groups A and B.There were no significant differences in the radiation dose of dynamic monitoring scans (0.056±0.026 mSv vs.0.062±0.018 mSv,P=0.068) and radiation dose of angiography (0.94±0.07 mSv vs.0.96±0.15 mSv,P=0.926) between the two groups,while 15 mL less contrast material volume was administered in the group A than the group B.Conclusion Bolus-tracking technique with shortened time of respiratory in Flash mode of dual-source CT yields the similar homogeneous enhancement with less contrast material in comparison to the test bolus technique.

  6. The influence of body mass index and gender on coronary arterial attenuation with fixed iodine load per body weight at dual-source CT coronary angiography

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Xiaomei; Zhu, Yinsu; Xu, Hai; Tang, Lijun; Xu, Yi [Dept. of Radiology, the First Affiliated Hospital of Nanjing Medical Univ., Nanjing, Jiangsu (China)], E-mail: lijun.tang@hotmail.com

    2012-07-15

    Background. Most of current coronary CT angiography protocols are not adapted to body weight (BW) or cardiac output and no literature about influence of gender on coronary attenuation are reported with administration of a fixed iodine load per BW. Purpose. To determine the influence of body mass index (BMI) and gender on coronary arterial attenuation if contrast material dose is linearly adjusted to a patient's BW at dual-source CT coronary angiography (DSCT-CA). Material and Methods. A total of 207 consecutive patients (mean age 60.6 years) undergoing DSCT-CA were included. Contrast material (370 mg I/mL) dose calculation was randomly categorized into two groups (Group1: 1.10 mL/kg for men and women; Group 2: men 1.10 mL/kg, women 0.99 mL/kg) and flow rate was calculated as dose was divided by scan time plus 8 s. Mean arterial attenuations between men and women were compared with respect to attenuations of ascending aorta (AA) above coronary ostia, left main coronary artery (LM), proximal segments of right coronary artery (RCA), left anterior descending (LAD), and left circumflex artery (LCX) in two groups, respectively. Attenuations of coronary arteries were correlated with BW and BMI with simple linear regression. Results. The mean attenuations of AA, LM, RCA, LAD, and LCX were 407.8 {+-} 53.6 HU, 412.6 {+-} 55.4 HU, 411.4 {+-} 64.3 HU, 399.1 {+-} 56.7 HU, and 399.1 {+-} 60.2 HU, respectively, and there were no significant differences between men and women in group 1 (AA, P = 0.571; LM, P = 0.670; RCA, P = 0.737; LAD, P = 0.439, and LCX, P = 0.888). In group 2, the mean attenuations of AA, LM, RCA, LAD, and LCX in men were significantly higher than those in women (AA, P = 0.008; LM, P = 0.025; RCA, P = 0.017; LAD, P = 0.015, and LCX, P = 0.002). Positive linear regression between BW and attenuations of AA (R{sup 2} = 0.047, P = 0.02), LM (R{sup 2} = 0.036, P = 0.04), RCA (R{sup 2} = 0.080, P < 0.01), LAD (R{sup 2} = 0.078, P < 0.01), and LCX (R{sup 2} = 0

  7. Assessment of Acute Chest Pain with Dual-Source CT%双源CT对急性胸痛的诊断价值

    Institute of Scientific and Technical Information of China (English)

    李宇; 范占明; 余婧; 耿冀; 叶红; 晏子旭; 张兆琪

    2011-01-01

    Objective To assess the accuracy of triple rule out protocol for acute chest pain with dual-source CT in emergency department. Methods 56 consecutive patients with acute chest pain were examined with triple rule out protocol on a dual-source scanner (Siemens) at a temporal resolution of 83 ms using a body-mass-adapted contrast material injection. The scanning range included the whole chest from the first ribs to the diaphragm. The level of the carina was defined as the trigger point where the second tube was switched on additionally. The tri-phase injection protocol was used to get enough enhancement of coronary arteries,pulmonary arteries and aortas. One patient was excluded because he was unable to hold breath during scanning. The remaining subjects underwent more than 30 days follow-up. Results All examinations showed an adequate contrast enhancement of the pulmonary arteries, coronary arteries and aortas. The mean volume of contrast medium was (88±5 ) ml. The median radiation exposure was 11.6 mSy (95 %CI 6.9-13.1 ). 14 patients showed coronary arteries atherosclerosis, including coronary arterial stenosis more than 50% in 13 and 12 patients underwent the coronary stent implantation. 11 patients suffered from aortic dissection(Stanford type A), and 11 patients with pulmonary embolism (PE). In brief, the reasons of the chest pain were complex. 7 of the patients suffered from several kinds of chest diseases. The sensitivity and specificity in diagnosing acute chest pain were 98% and 96% ,respectively with CTA. There were no adverse outcomes follow-up for 30 days in this group. Conclusion Triple rule out coronary CT angiography in evaluation of the patients with acute chest pain presented to the emergency department is very helpful, safety and effective way.%目的 评价双源CT胸痛三联扫描计划对急诊胸痛诊断的准确性.方法 按照入选标准连续选取急性胸痛患者56例,采用西门子双源CT扫描仪胸痛三联扫描计划

  8. Dual-source dual-energy CT for the differentiation of urinary stone composition: preliminary study%双源CT双能量成像对泌尿系统结石成分分析的初步研究

    Institute of Scientific and Technical Information of China (English)

    杨琪放; 严景民; 张挽时; 孟利民; 时惠平; 王东; 毕永民; 李相生; 方红; 郭和清

    2011-01-01

    氨酸结石、混合尿酸结石与其他类型结石.%Objective To evaluate dual-source dual-energy CT(DSCT) for the differentiation of urinary stone composition in vitro. Methods Ninety-seven urinary stones were obtained by endoscopic lithotripsy and scanned using dual-source dual-energy CT. The stones were divided into six groups according to infrared spectroscopy stone analysis: uric acid ( UA ) stones ( n = 10 ), cystine stones ( n = 5 ), struvite stones( n = 6), calcium oxalate ( CaOx ) stones ( n = 22 ), mixed UA stones ( n=7 ) and mixed calcium stones(n=47). Hounsfield units (HU) of each stone were recorded for the 80 kV and the 140 kV datasets by hand-drawing method. HU difference, HU ratio and dual energy index ( DEI ) were calculated and compared among the stone groups with one-way ANOVA. Using dual energy software to determine the composition of all stones, results were compared to infrared spectroscopy analysis. Results There were statistical differences in HU difference [(-17±13), (229±34),(309 ±45), (512 ±97), (201±64)and (530±71) HU respectively], in HU ratio (0.96±0.03, 1.34 ±0.04, 1.41 ±0.03, 1.47 ±0.03,1.30±0.07, and 1.49 ±0.03 respectively), and DEI( -0.006 ±0.004, 0.064 ±0.007, 0.080 ±0. 007, 0. 108±0.011 ,0. 055 ±0.014 and 0. 112 ±0.008 respectively ) among different stone groups(F=124. 894,407.028, 322. 864 respectively, P <0. 01 ). There were statistical differences in HU difference,HU ratio and DE1 between UA stones and the other groups( P < 0. 01 ). There were statistical differences in HU difference, HU ratio and DEI between CaOx or mixed calcium stones and the other four groups (P<0. 01 ). There was statistical difference in HU ratio between cystine and struvite stones ( P < 0. 01 ). There were statistical differences in HU difference, HU ratio and DEI between struvite and mixed UA stones (P<0. 05 ). Dual energy software correctly characterized 10 UA stones, 4 cystine stones, 22 CaOx stones and 6 mixed UA

  9. 双源CT增强扫描检查对肠梗阻患者梗阻部位和梗阻病因的诊断意义%Diagnostic Value of Dual Source CT Enhanced Scan of Intestinal Obstruction

    Institute of Scientific and Technical Information of China (English)

    易琳; 芮军; 相运勇; 袁鑫鑫

    2016-01-01

    Objective To analyze the obstruction site,etiology,diagnosis by dual source CT scan significance. Methods From January 2015 to January 2016 in our hospital to receive treatment for intestinal obstruction in 32 patients for the study,patients admit ed to hospital,administering dual-source CT enhanced scan,clinical data,the inspection process,the diagnosis of patients,etc. were retrospel tively and analyzed. Results The di-agnosis of obstruction,the dual-source CT scan diagnosis entirely consistent with fiber endoscopy findings and surgical results,the site of obstruction diagnosed as 100%in the diagnosis of obstructive reasons,only one case was misdiagnosed as Crohn's disease intestinal tuberculosis,other reasons are consistent with the results of fiber endoscopy and surgical results,cause of obstruction diagnosis was 96. 9%. Conclusion The dual-source CT applied to the site of obstruction and to diagnose the cause can improve the diagnosis rate,to provide a reliable reference for the development of clinical programs.%目的:分析在肠梗阻部位、病因诊断中应用双源CT增强扫描的意义。方法选择2015年1月至2016年1月接收治疗的肠梗阻患者32例为研究对象,患者入院时,施予双源CT增强扫描检查,对患者临床资料、检查过程、诊断结果等进行回顾性分析。结果在梗阻部位的诊断中,双源CT增强扫描诊断结果与纤维镜检查结果和手术结果完全一致,梗阻部位确诊率为100.0%,在梗阻原因的诊断中,仅有1例克罗恩病被误诊为肠结核,其他原因均与纤维镜检查结果和手术结果一致,梗阻原因确诊率为96.9%。结论将双源CT应用到肠梗阻部位及原因的诊断中可提高确诊率,为临床治疗方案的制定提供可靠参考。

  10. Dual-Source Dual-Energy CT for the Differentiation of Urinary Stone Composition: In Vivo Study%体内泌尿系结石的双源CT双能量成像

    Institute of Scientific and Technical Information of China (English)

    张挽时; 杨琪放; 孟利民; 郭和清; 严景民; 刘红明

    2012-01-01

    件可以较好地区分体内的尿酸结石、混合尿酸结石、胱氨酸结石和含钙结石,但区分磷酸镁铵结石以及不同成分的含钙结石尚存在困难.%Objective To evaluate the ability of dual-source dual-energy CT to differentiate urinary stone of different compositions in vivo. Methods Sixty-four patients with known urinary stone disease were scanned using a DSCT scanner in the dual-energy mode. Hounsfield units (HU) of each stone were recorded for the 80 kV and the 140 kV datasets by hand-drawing method. HU difference, HU ratio and DEI were calculated. Urinary stones were classified as UA stones, mixed UA stones, cystine stones and calcium stones based on dual energy software, the results compared with the infrared spectroscopy analysis of stone samples. Use one-way ANOVA to compare HU difference, HU ratio and DEI of different stones groups according to infrared spectroscopy. Results In 55 patients, stones were sampled. Dual energy software correctly characterized 4 UA stones, 1 mixed UA stone, 2 cystine stone, and 42 calcium stones. 4 struvite stones, 1 mixed ammonium uratc and calcium stone, 1 mixed UA stone were classified as calcium stones. Statistical differences in HU difference (18±12), (214±21), (329±35), (360±49), (458±97) and (497±110) HU respectively, HU ratio (1.04±0.02, l.36±0.02, 1.49±0.04, 1.50±0.08. 1.52±0.05 and 1.53±0.04 respectively), and DEI (0.006±0.004, 0.062±0.002, 0.089±0.006, 0.095±0.0l3, 0.107±0.011 and 0.112±0.012 respectively) among UA stones, cystine stone, stravite stones, CaP stones, CaOx stones and mix calcium stones (P<0.001). There were statistical differences in HU difference, HU ratio and DEI between UA stones and ihe other groups, in HU ratio and DEI between cystine stones and the other groups, in HU difference and DEI between struvite stones and CaOx or mix calcium stones, in HU difference between cystine stones and CaOx or mix calcium stones, in DEI between CaP stones and mix

  11. Dual-Energy Imaging of Urate Crystals in Gout Using Dual-Source CT%双源CT双能量成像对痛风诊断价值的初步研究

    Institute of Scientific and Technical Information of China (English)

    靳国庆; 王东林; 王振杰; 李麦福

    2013-01-01

    目的 探讨双源CT双能量成像(DECT)技术在痛风患者四肢关节尿酸盐结晶的显示能力及其临床应用价值,并就DECT对痛风的疗效进行初步评估.方法 病例组为临床确诊为痛风或高尿酸血症患者50例,男46例,女4例,足45例,手5例;对照组为非痛风患者10例,两组性别及年龄比较,差异无统计学意义(P年龄=0.234,P性别=0.612,P>0.05).分别对其足/手行DECT非增强扫描及薄层重组(0.75 mm),将原始数据输送加载入Du-al-EnergyGOUT软件内进行图像后处理,比较病例组和对照组患者尿酸盐沉积的差异以及DECT检测尿酸盐沉积部位与临床评估的差异.采用t检验,Fisher精确概率进行统计学分析.结果 病例组均获得了较满意的DECT图像,显示尿酸盐结晶沉积478处,最少2处,最多24处,以足踝部病灶最多;对照组均未见尿酸盐结晶沉积,检出率两组相比,差异有显著统计学意义(P =0.00012,P<0.001).结论 DECT技术可明确显示尿酸盐结晶沉积,对于关节痛及疑似痛风患者,尤其是痛风早期有较高的检出率.经引导下穿刺抽吸,与CT像一致,具有较高的临床应用价值,可作为痛风筛选的常规检查项目,但就DECT对痛风疗效的评估有待于收集更多的病例进一步研究.%Objective To evaluate the capabilities and efficacy of dual energy CT (DECT) in displaying urate crystals in extremities joints of gout. Methods In study group, 50 clinically confirmed patients (46 males and 4 females) with gout or hyperuricemia were collected. Gout involved feet in 45 cases,hands in 5. In control group, 10 normal volunteers were collected. There was no significant difference between the two groups on age and gender (Page =0. 234,Pgendex= 0.612,P >0.05). DECT noncontrast scanning and thin sliced (0.75 mm) reconstruction of foot / hand were performed. The urate deposition were compared between 2 groups. Results The high quality dual energy images were obtained in all

  12. 双源CT双步触发技术用于心脏扫描%Application of dual-step prospective ECG-triggered dual-source CT in cardiac scan

    Institute of Scientific and Technical Information of China (English)

    李强; 钱农; 钱波; 徐烈福; 孟名柱; 潘昌杰

    2013-01-01

    Objective To introduce the application of dual-step prospective ECG-triggcrcd technical of DSCT in coronary angiog-raphy and left ventricular function analysis simultaneously. Methods Fifty-three consecutive patients suspected or diagnosed with coronary disease were examined by cardiac DSCT and MRI. Sequential acquisition and dual-step prospective ECG-triggcr were used in DSCT. Full tube current output in tube A at 70% ( HR≤70 bcats/min)or 40% ( HR>70 bcats/min) R-R interval according to heart rates and 20% tube current output in tube B at 30%-90% R-R interval in all patients. The coronary artery was divided into 16 segments according to the American Heart Association. Image quality of coronary arteries were graded with 4-point scale. LVES, LVED and LVEF were evaluated in DSCT and MR]. Paired it-test and pcarson correlation were statistically analysed. Results Fifty cases accomplished examination successfully. The average radiation docs was(3. 33±0. 65) mSv. In 669 evaluated coronary segments, 97. 76% could be diagnosed . Paired it-test indicated that the LVES, LVED and LVEF of DSCT and MR] had no significant statistically differences(P = 0. 91 ,0. 12 and 0. 16)and the correlation was good (r = 0. 96,0. 97 and 0. 89). Conclusion The second generation DSCT with dual-step prospective ECG-triggcrcd sequential acquisition can be used in coronary angiography and left ventricular function analysis simultaneously with good imaging quality of the coronary artery, reliable analysis of left ventricular function and lower radiation dose.%目的 探讨第二代双源CT(dual-source CT,DSCT)双步触发技术在冠状动脉造影兼顾左心室功能分析中的应用价值.方法 连续53例临床怀疑或确诊为冠状动脉心脏病的患者行冠状动脉DSCT造影和心脏MRI检查.DSCT采用序列扫描模式,前瞻性心电门控双步触发.扫描窗宽30%~90%R-R间期,依据不同的心率,仅在70%(心率≤70次/min)或40%(心率>70次/min)R-R间期全电

  13. Comparison of Diagnosis Value of MRI and Dual-Source CT in Knee-Joint Trauma%磁共振和双源CT在膝关节外伤中的诊断价值对比

    Institute of Scientific and Technical Information of China (English)

    杨进军; 何桂茹; 班允清

    2015-01-01

    目的 对磁共振和双源CT在膝关节外伤中的诊断价值进行对比分析. 方法 整群选取该院2011年1月—2014年5月间收治的141例膝关节外伤患者的影像资料进行回顾性分析,以手术结果作为参照,对比两种检测方法的诊断准确率.结果 双源CT与MRI对膝关节外伤的检出率分别为70.9%与94.3%,组间比较MRI的检出率显著高于CT,差异具有统计学意义(P<0.05). 以手术结果作为参照,对不同类型膝关节外伤的诊断准确率进行比较显示,MRI对于骨质损伤、韧带损伤、半月板损伤及关节囊积液的显示情况均优于双源CT,差异有统计学意义(P<0.05). 结论 MRI对于膝关节外伤的各项检出率均高于双源CT. 术前通过MRI全面检查掌握膝关节损伤情况,有助于帮忙骨科医生合理制定手术预案.%Objective To analyze and compare the diagnosis value of MRI and dual-source CT in knee-joint trauma. Methods The images about 141 patients with knee-joint trauma treated from January 2011 to May 2014 in our hospital were retrospectively analyzed. According to the operation results, the detection accuracy based on two methods was compared. Results The detection rate of knee-joint trauma based on dual-source CT and MRI was 70.9% and 94.3%. The rate of MRI was higher than that of CT (P<0.05); according to comparison results of detection accuracy for different types of knee-joint trauma, the imaging of injury of bone, ligamentous injury, meniscus injury and drainage of articular capsule based on MRI was significantly better than that of du-al-source CT (P<0.05). Conclusion The detection rate of knee-joint trauma based on MRI is higher than that of dual-source CT. Be-fore surgery, the complete inspection of knee-joint injury based on MRI is good for the orthopedists to make the reasonable opera-tion planning.

  14. Dual energy CT in patients with polycystic kidney disease

    Energy Technology Data Exchange (ETDEWEB)

    Arndt, Nikolaus; Reiser, Maximilian F.; Graser, Anno [University of Munich, Department of Clinical Radiology, Munich (Germany); Staehler, Michael [University of Munich, Department of Urology, Munich (Germany); Siegert, Sabine [University of Munich, Department of Pathology, Munich (Germany)

    2012-10-15

    To evaluate the diagnostic efficacy of dual source-dual energy CT (DECT) in the detection of neoplasia in patients with polycystic kidney disease (PKD). A total of 21 patients with PKD underwent DECT on a dual source system, using kVp settings of Sn140/100 or 140/80. Colour-coded iodine maps and virtual unenhanced images were used to determine enhancement within cysts and to differentiate haemorrhagic from simple cysts. A cut-off of 15 HU was used as a threshold for malignancy. In patients with malignancy, histopathology was the gold standard; otherwise, patients underwent follow-up imaging for 150-908 days. On the basis of measured enhancement, 13 enhancing masses were seen in 4 patients (12 renal cell cancers and 1 adenoma); follow-up imaging showed no malignancy in 18 patients. Cysts did not enhance by more than 15 HU, whereas masses showed a mean enhancement of 45 (25-123) HU. Average radiation exposure was 9.6 mSv for the biphasic protocol and 5.8 mSv for DECT only. DECT greatly facilitates the detection of malignancy in patients with polycystic kidney disease, at the same time reducing radiation exposure by omission of a true unenhanced phase. (orig.)

  15. 单次对比增强双源双能量CT血管成像评估颅内出血及其原因%Evaluation of intracranial hemorrhage and its causes by single-contrast-enhanced dual-source dual-energy CT angiography

    Institute of Scientific and Technical Information of China (English)

    柴学; 张龙江; 盛会雪; 金征宇; 张兆琪; 卢光明

    2012-01-01

    目的 随着双源CT在临床的推广应用,双源CT双能量成像已成为研究热点.文中探讨单次对比增强的双源双能量CT血管血管成像 (CT angiography,CTA)对评估颅内出血及其原因的应用价值.方法对43例蛛网膜下腔出血患者进行双源CT头颅常规平扫(conventional nonenhanced CT,CNCT)及对比增强双能量CT扫描(80kV/400mA和140kV/95mA).利用Liver VNC软件进行对比增强双能量CT数据处理得到虚拟平扫(virtual nonenhanced CT,VNCT)数据,与CNCT检出的蛛网膜下腔出血比较,分析CNCT和VNCT的图像质量、辐射剂量、平均CT值、信噪比、对比噪声比及病灶检出率的差异.利用双能量CTA判断颅内血管异常,并与数字减影血管造影(digital subtraction angiography,DSA)所检出的病变比较诊断符合率.结果 双能量VNCT的图像质量低于常规平扫(Z值=-6.576,P<0.01),但可满足临床诊断要求.VNCT的正常脑组织及出血区CT值、信号噪声比(signal-to-noise ratio,SNR)及对比噪声比(contrast-to-noise ratio,CNR)低于CNCT(P<0.01).VNCT和CNCT对病灶的检出结果 相似.在43例临床疑有脑血管病变的患者中,双能量CTA检出25例患者为动脉瘤,4例为动静脉畸形,3例为烟雾病,11例为阴性,与DSA或手术证实结果 完全一致.双能量CTA患者接受的辐射剂量明显低于常规DSA(P<0.01).结论 从双源双能量CT中获得VNCT平扫图像可用于诊断颅内出血,图像质量可满足临床诊断需要.双能量CTA与DSA的诊断符合率很高.应用该技术可减少每次平扫所接受的辐射剂量,具有潜在的临床应用价值.%Objective Dual-source dual-energy CT imaging is becoming a focus of research with its wide clinical application . This study aimed to investigate intracranial hemorrhage and its causes by single contrast-enhanced dual-source dual-energy CT angiography (CTA). Methods Forty-three patients suspected of subarachnoid hemorrhage underwent head conventional

  16. Comparison of dual-source CT angiography and MR angiography in preoperative evaluation of intra- and extracranial vessels: a pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Muehlenbruch, Georg; Das, Marco; Mahnken, Andreas Horst; Guenther, Rolf W. [RWTH Aachen University, Department of Diagnostic and Interventional Radiology, Aachen (Germany); Mommertz, Gottfried; Langer, Stefan [RWTH Aachen University, Department of Vascular Surgery, Aachen (Germany); Schaaf, Meike; Thron, A.; Krings, Timo [RWTH Aachen University, Department of Neuroradiology, Aachen (Germany); Wildberger, Joachim Ernst [University Hospital Maastricht, Department of Radiology, Maastricht (Netherlands)

    2010-02-15

    Besides the assessment of carotid artery stenosis, evaluation of the vascular anatomy and lesions within both the extra- and intracranial arteries is crucial for proper clinical evaluation, treatment choice and planning. The purpose of our study was to evaluate the potential of dual-source CTA and 3T-MRA. In 16 symptomatic CAS patients, contrast-enhanced DSCT and 3T-MRA examinations were performed. For DSCT a dual-energy protocol with a 64 x 0.6-mm collimation was applied. In 3T-MRA intracranial high-resolution unenhanced TOF and extracranial contrast-enhanced MRA were performed. All examinations were analyzed for relevant morphologic and pathologic features or anomalies, and a total of 624 vessel segments were scored. All examinations were of diagnostic image quality with good to excellent vessel visibility. Almost all intracranial arteries were significantly better visualized by MRA compared to CTA (five of six vessels, p < 0.05). DSCT however allowed for further morphological carotid stenosis description, especially with respect to calcification. Although MRA proved to be superior in visualization of smaller intracranial arteries, all pre-interventionally relevant information could be perceived from DSCT. DSCT and MRA may both be regarded as a reliable, fast, pre-interventional imaging investigation in patients with carotid artery stenosis. (orig.)

  17. Preliminary study of application value dual-source CT combined with manometric examination on OSAHS%探讨气道双源CT和测压检查对OSAHS的联合应用价值

    Institute of Scientific and Technical Information of China (English)

    王志文; 许凌云; 张晓馨

    2013-01-01

    目的 初步探讨应用双源CT联合测压法评价OSAHS患者上气道阻塞层面的应用价值.方法 通过上气道双源CT判定结果与测压结果进行对照研究,并分析两种方法联合应用判定阻塞层面临床应用价值.结果 双源CT检查判定OSAHS患者上气道狭窄平面的阳性率为83.33%(25/30).AG200判定OSAHS患者上气道间隙阻塞的阳性率为90%(27/30).两种检查结合的阳性率可以达到96.66%(29/30).结论 双源CT检查和AG200对OSAHS患者上气道阻塞均具有诊断意义,CT检查可以反映上气道多平面联合狭窄和上气道解剖性狭窄的原因,AG200仅能单纯显示单一平面的阻塞情况.联合应用两种检查手段可以明显提高OSAHS患者诊断的阳性率,并且在形态学和功能状态表现上可以相互弥补不足,为临床提供更可靠治疗依据.%Objective To preliminarily diseuss the application value of dual-source CT combined with manometric method for evaluation of upper airway obstruction level in patients with OSAHS. Methods Through the upper airway of dual-source CT judgement result, manometric findings were compared. We combined the two methods to determine the clinical value of block level. Results Dositive rate with dual-source CT scan determining the upper airway stenosis in patients with OSAHS was 83. 33% (25/30) , AG200 determining OSAHS patients on positive airway obstruction clearance rate was 90%(27/30). Two kinds of checks can be achieved with the positive rate of 96. 66% (29/30). Conclusion Dual-source CT and AG200 of the upper airway obstruction in patients with OSAHS can make a diagnosis, CT examination can reflect on the multi-planar joint narrow airway and upper airway anatomic stenosis of the reasons, AG200 alone showed only a single plane of obstruction. Combination of two kinds of inspection methods can significantly improve the positive rate of diagnosis of OSAHS patients. And morphological and functional status in each other can

  18. Utility of virtual endoscopy in coronary dual-source CT angiography: initial experience%仿真内镜用于双源CT冠状动脉成像的初步经验

    Institute of Scientific and Technical Information of China (English)

    何卫红; 陈伟; 周晖

    2011-01-01

    目的 初步探讨双源CT冠状动脉成像时利用仿真内镜诊断冠状动脉疾病的潜在价值.方法 使用Fly-through软件对40例双源CT冠状动脉成像病例行仿真内镜观察,并与CT冠状动脉成像常规方法和传统冠状动脉造影术进行比较.结果 40例患者共120支冠状动脉中,92%(110/120)的冠状动脉可行仿真内镜成像;仿真内镜判断有意义的冠状动脉狭窄正确率为85%( 41/48);常规CT冠状动脉成像不能判断的9处严重钙化,仿真内镜显示为显著或高度狭窄;4枚冠状动脉支架内和3支桥血管仿真内镜显示通畅.结论 仿真内镜可立体显示正常和病变冠状动脉腔内情况,是CT冠状动脉成像后处理方法的的重要补充.%[Objective] To explore the potential clinical value of virtual endoscopy in detecting coronary artery lesions. [Methods] Forty patients underwent dual-source CT coronary angiography. Virtual endoscopies were simulated in 120 coronary arteries using the Fly-through software, with routine imaging post-processing methods of CT coronary angiography and conventional coronary angiography as the reference standard. [Results] Virtual endo- scopies of 92% (110/120) major coronary artery were successfully performed with good image quality, and the accuracy of virtual coronary angioscopy was 85% (41/48) for detecting hemodynamically significant stenoses confirmed by conventional coronary angiography. Using virtual coronary angioscopy, 9 severe calcified coronary arteries were identified as significant or severe stenoses, while unable to estimate by routine CT coronary angiography. Virtual endoscopies of intracoronary stents (n=4) or bypass grafts (n=4) were patency. [Conclusions] Endoscopy of coronary arteries using dual-source CT allows comprehensive 3-dimensional delineation of the vessel lumen, and can be used as an important complement to the routine post-processing methods of CT coronary angiography in some cases.

  19. Dual source spiral CT three dimensional reconstruction in the interventional treatment of liver cancer%双源螺旋CT三维重建技术在肝癌介入治疗中的应用

    Institute of Scientific and Technical Information of China (English)

    王东林; 陈广礼

    2011-01-01

    目的 探讨双源螺旋CT三维重建技术在肝癌介入治疗中的应用价值.方法 对37例肝癌患者进行双源螺旋CT扫描诊断后,在后处理工作站进行容积再现(VR)、最大密度投影(MIP)血管重建.结果 肝动脉期VR图像和MIP多平面重建图像均能清晰显示腹腔干、脾动脉、肝总动脉左右动脉及其2~3级分支,还能清晰显示1~6级门静脉血管结构及1~3级肝静脉血管分支,具有较强的空间立体感.结论 双源螺旋CT门静脉三维重建成像是一种快捷而有效的无创性血管造影技术,有助于临床治疗方案的合理选择及疗效随访.%Objective To investigate the value of dual source spiral CT three dimensional reconstruction in the interventional treatment. Methods Totally 37 patients with liver cancer for dual source spiral CT scan diagnosis, in the post -processing workstation for volume rendering ( VR), maximum intensity projection (MIP) revascularization. Results The hepatic arterial phase MIP,VR images and multiplanar reconstruction images could clearly show the celiac trunk, splenic artery, hepatic artery about 2 ~ 3 artery and its branches, but also clearly show the 1 ~ 6 Class doors and 1 vein structure three branches of hepatic veins, with a strong spatial dimension. Conclusions The dual source spiral CT three dimensional reconstruction of portal vein imaging is a fast and effective non - invasive vascular imaging techniques, useful in clinical treatment choice and efficacy of a reasonable follow - up.

  20. Virtual non-contrast CT using dual energy spectral CT: Feasibility of coronary artery calcium scoring

    Energy Technology Data Exchange (ETDEWEB)

    Song, In Young; Yi, Jeong Geun; Park, Jeong Hee [Dept. of Radiology, Konkuk University School of Medicine, Seoul (Korea, Republic of); Lee, Sung Mok; Lee, Kyung Soo; Chung, Myung Jin [Dept. of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2016-06-15

    To evaluate the feasibility of coronary artery calcium scoring based on three virtual noncontrast-enhanced (VNC) images derived from single-source spectral dual-energy CT (DECT) as compared with true noncontrast-enhanced (TNC) images. This prospective study was conducted with the approval of our Institutional Review Board. Ninety-seven patients underwent noncontrast CT followed by contrast-enhanced chest CT using single-source spectral DECT. Iodine eliminated VNC images were reconstructed using two kinds of 2-material decomposition algorithms (material density iodine-water pair [MDW], material density iodine-calcium pair [MDC]) and a material suppressed algorithm (material suppressed iodine [MSI]). Two readers independently quantified calcium on VNC and TNC images. The Spearman correlation coefficient test and Bland-Altman method were used for statistical analyses. Coronary artery calcium scores from all three VNC images showed excellent correlation with those from the TNC images (Spearman's correlation coefficient [ρ] = 0.94, 0.88, and 0.89 for MDW, MDC, and MSI, respectively; p < 0.001 for all pairs). Measured coronary calcium volumes from VNC images also correlated well with those from TNC images (ρ = 0.92, 0.87, and 0.91 for MDW, MDC, and MSI, respectively; p < 0.001 for all pairs). Among the three VNC images, coronary calcium from MDW correlated best with that from TNC. The coronary artery calcium scores and volumes were significantly lower from the VNC images than from the TNC images (p < 0.001 for all pairs). The use of VNC images from contrast-enhanced CT using dual-energy material decomposition/suppression is feasible for coronary calcium scoring. The absolute value from VNC tends to be smaller than that from TNC.

  1. Correlation between Coronary Artery Stenosis and Plaque Nature Dual-Source Computed Tomography for Coronary Angiography%双源 CT 对冠状动脉狭窄及斑块性质的应用价值

    Institute of Scientific and Technical Information of China (English)

    柏辉; 李国晖

    2015-01-01

    目的:探讨双源CT对冠状动脉狭窄及不同性质冠状动脉斑块的诊断价值。方法:对50例临床确诊及拟诊冠心病患者行双源CT冠状动脉成像(CCTA)检查及冠状动脉造影(CCA),以CCA结果为参考标准,评估双源CT对不同性质斑块所致冠状动脉狭窄的特异度、敏感度、阳性预测值、阴性预测值及准确性,分析狭窄程度与斑块成分间的相关性。结果:与CCA对照,50例患者中,双源CT对诊断冠状动脉狭窄的特异度、敏感度、阳性预测值、阴性预测值依次如下:轻度狭窄分别为98.9%、46.7%、77.8%、95.8%;中度狭窄分别为97.6%、71.0%、84.6%、94.8%;重度狭窄分别为96.6%、96.4%、96.4%、98.6%。误诊冠状动脉狭窄共20支,诊断符合率为89.8%。对非钙化性斑块所致管腔狭窄的诊断符合率达84.3%,高于钙化性斑块(76.9%)。结论:双源CT冠状动脉成像能够有效判断冠状动脉狭窄程度及斑块成分。%Objective: To discuss the diagnosis value for coronary artery of different components of plaque and stenosis by dual-source computed tomography coronary artery imaging.Method:A total of 50 pa-tients diagnosed with coronary heart disease underwent dual-source computed tomography coronary artery ( CCTA) imaging and coronary angiography( CCA) .The specificity,sensitivity, positive predictive value,neg-ative predictive value,and accuracy for the quantitative detection of stenosis assessed.Result:In the 50 pa-tients,The specificity,sensitivity, positive predictive value,negative predictive value and accuracy for the de-tection of coronary artery stenosis assessed with dual-source CT were respectively:for<50 stenosis,98.9%, 46.7%,77.8%,95.8%;for 50 ~74 stenosis,97.6%,71.0%,84.6%,94.8%;for≥75 stenosis,96.6%、96. 4%、96.4%、98.6%.Comparing with CCA,misdiagnosis was observed in 20 of 196 arteries with dual-source CT

  2. 双源CT肺动脉成像在肺动脉栓塞诊断中的应用价值%Application of dual-source CT pulmonary angiography in the diagnosis of pulmonary embolism

    Institute of Scientific and Technical Information of China (English)

    张谷青; 陈月芹; 孙新海; 史志涛; 张新东; 王皆欢

    2011-01-01

    Objective : To explore the value of dual-source CT angiography of pulmonary arteries in the diagnosis of pulmonary embolism. Methods: 58 patients suspected of having pulmonary embolism were examined with dual-source CT pulmonary angiography. The effects of imaging in displaying pulmonary embolism on MPR , MIP , VR and CTVE were compared. The direct signs, the indirect signs and types were analyzed. Results : 45 cases with pulmonary embolism were diagnosed. A total of 658 emboli were found by dual-source CT , 170 of which were central type, 208 were eccentric type , 74 were mural type,and 206 were complete occlusion type. Indirect signs included mosaic sign (13 cases) , pleural effusion (27 cases) ,pulmonary artery hypertension (7 cases) , and pulmonary infarct (18 cases). 658 emboli were found on MPR,584 on MIP.the effect of VR and CTVE were not good (249 and 75 emboli were found). MIP,VR and CTVE were obviously inferior to MPR (P<0.05). Conclusion : The dual-source CT pulmonary angiography is a convenient, fast and reliable method for demonstration of pulmonary embolism. MPR, MIP,VR and CTVE play an important role in the diagnosis of pulmonary embolism.and MPR is the best among them.%目的:探讨双源CT肺动脉成像对肺动脉栓塞(PE)的诊断价值.方法:对58例临床拟诊为PE的患者行双源CT肺动脉成像,总结PE的直接、间接征象及分型,并比较MPR、MIP、VR和CTVE对肺动脉栓子的显示效果.结果:直接征象:58例中45例诊断为PE,共发现栓子 658支(中心型170支,偏心型208支,附壁型74支,完全闭塞型206支).间接征象:马赛克征13例,胸腔积液27例,肺动脉高压7例,肺梗死18例.MPR检出栓子658支,MIP检出584支,VR及CTVE对栓子的显示效果较差,分别为249支和75支.MIP、VR及CTVE对栓子的显示效果低于MPR,差异有统计学意义(P<0.05).结论:双源CT肺动脉成像能够方便、快捷、清楚地显示肺动脉栓子,对诊断PE有重要价值;MPR、MIP、VR和CTVE是

  3. Radiation Doses of Dual-Energy CT for Abdominopelvic CT: Comparison with Single-Energy CT

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Young Seo; Jeong, Woo Kyoung; Kim, Yong Soo; Heo, Jeong Nam [Dept. of Radiology, Hanyang University Guro Hospital, Hanyang University College of Medicine, Seoul (Korea, Republic of)

    2011-11-15

    To compare radiation doses of dual-energy CT (DECT) to single-energy CT (SECT) by a phantom experiment, with the application of mean tube currents for abdomino-pelvic CT. This study includes patients who were examined by contrast-enhanced CT for kidney evaluation. We divided the patients into six groups according to sex and body mass index. Each group consisted of five patients and a total of 30 patients were evaluated. We split the body parts (abdomen and pelvis), and calculated the mean tube current of each group as well as investigated the image noise. Applying the mean mAs from a CT scan, we measured the weighted CT dose index (CTDIw) of DECT and SECT. We compared the measured CTDIw to an estimated CTDI value displayed on the CT console. We also compared the radiation dose ratio of DECT to SECT (D/S ratio) for each subgroup. The radiation doses were compared by the student's t-test and analysis of variance. The difference of image noise between DECT and SECT was not statistically significant. Radiation dose of DECT was higher than SECT by about 21.6% (10.69 mGy, 8.79 mGy; p < 0.0001), and the measured CTDI of the DECT was significantly higher than the estimated CTDI by about 6% (p < 0.001). The D/S ratio was not significant between the six groups. The measured CTDIw of abdominopelvic DECT studies were significantly higher than those of SECT.

  4. New dual-source CT and dual-energy imaging in analysis of compositions of urinary calculi%新双源CT双能量成像对泌尿系结石成分定性诊断的价值

    Institute of Scientific and Technical Information of China (English)

    林黛英; 吴先衡; 汪丹凤; 林少帆; 黄宝泉

    2014-01-01

    目的 探讨新双源CT双能量成像分析泌尿系统结石成分的临床价值.方法 对45例尿路结石患者行双源CT双能量扫描,分析其结石成分,比较体外红外光谱法分析结石成分的结果,分析双源CT分析各种成分泌尿系结石的特异性与敏感性.结果 双源CT能准确区分尿酸结石和非尿酸结石,灵敏度和特异度均为100.00%;磷酸盐结石的诊断灵敏度为93.10%,特异度为92.00%;胱氨酸结石的诊断灵敏度为66.67%,特异度为97.90%;草酸钙结石灵敏度为85.71%,特异度为100.00%.结论 新双源CT双能量成像能在治疗前对泌尿系结石的成分进行分析,对结石的治疗及预防具有重要意义.%Objective To explore the clinical value of new dual-source CT and dual-energy imaging in the analysis of the compositions of urinary calculi.Methods The compositions of urinary calculi in 45 patients were analyzed being scanned with new dual-source CT and dual-energy imaging.The compositions of urinary calculi was compared with the results from infrared spectrometry in vitro.The sensitivity and specificity of the composition of urinary calculi were analyzed with new dual-source CT.Results Dual-source CT could accurately distinguish nonuric acid stones from uric acid calculi,and its sensitivity and specificity were both 100.00%; the diagnosis sensitivity and specificity to phosphate stones were 93.10% and 92.00%; the diagnosis sensitivity and specificity to cystine stones were 66.67% and 97.90%; and the diagnosis sensitivity and specificity to calcium oxalate stones were 85.71% and 100.00%.Conclusions Dual-source CT and dual-energy imaging can analyze the compositions of urinary calculi before treatment and has important significance in preventing and treating calculi.

  5. The value of low-dose prospective ECG-gated dual-source CT angiography in the diagnosis of coarctation of the aorta in infants and children

    Energy Technology Data Exchange (ETDEWEB)

    Nie, P. [Shandong Provincial Key Laboratory of Diagnosis and Treatment of Cardio-Cerebral Vascular Diseases, Shandong Medical Imaging Research Institute, Shandong University, Jinan, Shandong (China); Wang, X., E-mail: wxming369@yahoo.com.cn [Shandong Provincial Key Laboratory of Diagnosis and Treatment of Cardio-Cerebral Vascular Diseases, Shandong Medical Imaging Research Institute, Shandong University, Jinan, Shandong (China); Cheng, Z.; Duan, Y.; Ji, X. [Shandong Provincial Key Laboratory of Diagnosis and Treatment of Cardio-Cerebral Vascular Diseases, Shandong Medical Imaging Research Institute, Shandong University, Jinan, Shandong (China); Chen, J. [CT Research Collaboration, Siemens, Beijing (China); Zhang, H. [Department of Cardiovascular Surgery, Shandong Provincial Hospital, Jinan, Shandong (China)

    2012-08-15

    Aim: To investigate the value of prospective electrocardiogram (ECG)-gated dual-source computed tomography (DSCT) in the diagnosis of coarctation of the aorta (CoA). Materials and methods: Seventeen patients clinically suspected of having CoA underwent prospective ECG-gated DSCT angiography and transthoracic echocardiography (TTE). Surgery was performed in all patients. The diagnostic accuracy of DSCT angiography and TTE was compared with the surgical findings as the reference standard. Image quality was evaluated using a five-point scale. Effective radiation dose was calculated from the dose-length product (DLP). Results: CoA was diagnosed in 17 patients by DSCT angiography and in 16 patients by TTE. A total of 46 separate cardiovascular abnormalities were confirmed by surgical findings. The diagnostic accuracy of DSCT angiography and TTE was 96.32% and 97.06%, respectively. There was no significant difference in the diagnostic accuracy between DSCT angiography and TTE ({chi}{sup 2} = 0, p > 0.05). The mean score of image quality was 4.2 {+-} 0.8. The mean effective dose was 0.69 {+-} 0.09 mSv. Conclusion: Prospective ECG-gated DSCT with a low radiation dose is a valuable technique in the diagnosis of CoA in infants and children.

  6. Role of dual source CT perfusion imaging in the diagnosis of early radiation-induced lung injury%双源 CT灌注成像诊断早期放射性肺损伤的应用价值

    Institute of Scientific and Technical Information of China (English)

    潘利福; 邝平定

    2015-01-01

    Objective To examine the role of dual source CT perfusion imaging for early diagnosis of radiation -induced lung injury and to obtain scientific knowledge for early diagnosis of radiation induced lung injury .Method The level of dual source CT perfusion imaging perfusion values of the radiation-induced lung injury patients ( the experimental group , n=45 ) and that of the patients with no radiation-induced lung injury (the control group, n=45) was monitored.Meanwhile, the patients with radiation-induced lung injury were subjected to conventional CT examination .The sensitivity and accuracy of the two detection methods were then compared .Findings The values of lung tissue blood flow ( rrBF ) , relative blood volume ( rrBV) , relative blood capillary permeability ( chip) of the experimental group were significantly higher than those of the control group (P0.05).41 of the 45 patients of the experimental group were diagnosed as cases of radioactive lung injury.The diagnostic sensitivity and specificity were 91.1% and 97.78% respectively, which were significantly higher than those of the conventional CT technology (P<0.01).Conclusion Dual source CT perfusion imaging can display the changes after radiotherapy of lung hemodynamics and display early perfusion abnormalities in patients with radiation -induced lung injury.It can serve as an effective tool for early detection of radiation-induced lung injury .%目的:探讨双源CT灌注成像早期诊断放射性肺损伤的应用效果,为放射性肺损伤早期诊断提供依据。方法观察放射性肺损伤患者45例(观察组)和未发生放射性肺损伤患者45例(对照组)的双源CT灌注成像灌注值的水平,同时对放射性肺损伤患者采用常规的CT检查,比较两种检测方法的灵敏度和准确度。结果观察组肺组织相对血流量(rrBF)、相对血容量(rrBV)、相对毛细血管通透性(rrPS)均显著高于对照组(P<0.05);观察组45

  7. Application of dual-source 4D-CTA combined with CT perfusion imaging in diagnosis of acute cerebral ischemic diseases%双源CT 4D- CTA联合灌注成像在急性脑缺血性疾病中的应用价值

    Institute of Scientific and Technical Information of China (English)

    程有根; 杨光钊; 茅国群; 楼明芳; 魏福全

    2013-01-01

    Objective To investigate the application of dual- source four- dimensional CT angiography (4D- CTA) com-bined with CT perfusion imaging (CTPI) in diagnosis of acute cerebral ischemic diseases. Methods Thirty patients with clinical y suspected acute cerebral ischemic disease underwent head plain CT scan and whole brain CTPI examination 2~16h after onset, the images of CBF, CBV, MTT, TTP and 4D- CTA were obtained. Patients also underwent MRI examination in 1~3 d. The findings of plain CT scan, CTPI, 4D- CTA and MRI were analyzed. Results Plain CT scan found 16 ischemic lesions in 12 cases, CTPI found 32 ischemic lesions in 26 cases, MRI found 28 ischemic lesions in 25 cases, and 4D- CTA demonstrated various degree of stenosis or occlusion in supplying vessels in 20 cases. Conclusion Dual- source 4D- CTA combined with CT perfusion imaging provides comprehensive and detailed imaging information, so that has important value for early diagnosis and treatment in pa-tients with acute cerebral ischemia.%目的:探讨双源CT 4维血管造影(4D- CTA)及灌注成像(CTPI)在急性脑缺血性疾病中的应用价值。方法对30例临床拟诊为急性脑缺血性疾病的患者于发病2~24h内行头颅CT平扫和全脑CTPI检查,获得脑血流量、脑血容量、平均通过时间、达峰时间等参数图,同时获得4D- CTA图像;于发病的1~3d后行MRI检查,分析CT平扫、CTPI、4D- CTA、MRI表现。结果 CT平扫发现12例有16个缺血病灶,CTPI发现26例32个缺血病灶,MRI发现25例28个缺血病灶,4D- CTA显示有20例责任血管有不同程度的狭窄或闭塞。结论双源CT 4D- CTA联合灌注成像能为急性脑缺血患者提供全面、详细的影像学信息,对急性缺血性脑梗死的早期诊断和治疗有重要价值。

  8. Preliminary study of dual energy scanning of dual source CT for diagnosing hepatic tumors%双源CT双能量扫描在肝脏肿瘤应用价值的初步探讨

    Institute of Scientific and Technical Information of China (English)

    王翔; 王涛; 王小琴

    2013-01-01

    目的 探讨双源CT(DSCT)双能量扫描在肝脏肿瘤诊断中的应用价值.方法 回顾性分析2011年4~12月该院行DSCT扫描肝脏肿瘤患者20例的临床资料.结果 患者肝脏、脾脏、腹主动脉、脊柱后缘肌肉普通平扫与虚拟平扫(P>0.05),原发性肝癌与胆管细胞癌和肝海绵状血管瘤在碘图中差异有统计学意义(P0. 05). The iodine imaging showed statistical difference between primary liver cancer with bile duct cell carcinoma and hepatic cavernous hemangioma(P<0. 05). Conclusion Dual energy scanning of DSCT has the latent clinical application value in the diagnosis of hepatic tumors.

  9. 双能量CT在肾癌诊断及分型中的应用%Application of dual-source dual-energy CT scanning in diagnosis and typing of renal cell carcinoma

    Institute of Scientific and Technical Information of China (English)

    金原; 武志峰; 吴山; 刘世杰; 王沙沙

    2014-01-01

    Objective To investigate the value of dual-energy virtual unenhanced and dual-energy iodine value distribution diagram type of kidney cancer.Methods A retrospective analysis of 35 cases of renal cell carcinoma dual-energy CT scan data,compared to kidney pathology data,analyze the image quality and radiation dose dual-energy virtual unenhanced and dual energy distribution of iodine in clear cell carcinoma and non-clear cell carcinoma the differences that exist.Results Unenhanced and virtual unenhanced image quality was quite,CT value (routine unenhanced renal parenchyma 31.90±4.10 HU,abdominal aortic 45.60±6.30 HU,psoas 50.00±6.6 HU3,kidney 1.410±17.06 HU; virtual unenhanced renal parenchyma abdominal aortic 33.20±5.50 HU,48.30±8.00 HU,52.40±10.63 HU psoas kidney 0.87±17.48 HU),signal to noise ratio (routine unenhanced renal abdominal aorta 3.22±1.49,5.13±2.57,4.56±2.12 psoas kidney 3.24±2.27 virtual unenhanced renal abdominal aorta 2.73±1.08,3.79±1.64,3.23±1.35 psoas kidney 2.18± 1.57) had not significantly different (P > 0.05).Clear cell carcinoma of the skin medullart junction of iodinedistribution of images Iodine (2.75±1.05) mg/ml was higher than non-clear cell carcinoma (1.25±0.72) mg/ml,the difference was statistically significant (t =7.048,P < 0.05).Conclusions CT examination in patients with renal cell carcinoma virtual unenhanced image quality is similar with routine unenhanced image quality,it reduces radiation dose.The distribution of iodine can provide more diagnostic information that can help us be more intuitive and accurate judgments of the blood supply and kidney cancer subtypes.%目的 探讨双能量CT虚拟平扫及双能量碘分布图在肾癌诊断及分型中的应用价值.方法 收集35例肾癌患者双能量增强CT扫描数据及病理结果,分析双能量CT虚拟平扫的图像质量及辐射剂量、双能量碘分布图在透明细胞癌及非透明细胞癌中存在的差异.结果 虚拟平扫与常规平扫

  10. Diagnostic Value of 64-Slice Dual-Source CT Coronary Angiography in Patients with Atrial Fibrillation: Comparison with Invasive Coronary Angiography

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jian Jun; Liu, Tie; Feng, Yue; Wu, Wei Feng; Mou, Cai Yun; Zhai, Li Hao [Zhejiang Hospital, Hangzhou (China)

    2011-08-15

    We wanted to evaluate the image quality and diagnostic value of 64-slice dual-source computed tomography (DSCT) coronary angiography in patients with atrial fibrillation (Afib). The coronary arteries of 22 Afib patients seen on DSCT were classified into 15 segments and the imaging quality (excellent, good, moderate and poor) and significant stenoses ({>=} 50%) were evaluated by two radiologists who were blinded to the conventional coronary angiography (CAG) results. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for detecting important coronary artery stenosis were calculated. McNemar test was used to determine any significant difference between DSCT and CAG, and Cohen's Kappa statistics were calculated for the intermodality and interobserver agreement. The mean heart rate was 89 {+-} 8.3 bpm (range: 80-118 bpm). A range from 250 msec to 300 msec within the RR interval was the optimal reconstruction interval for the patients with Afib. The respective overall sensitivity, specificity, PPV and NPV values were 74%, 97%, 81% and 96% for reader 1 and 72%, 98%, 85% and 96% for reader 2. No significant difference between DSCT and CAG was found for detecting a significant stenosis (reader 1, p = 1.0; reader 2, p = 0.727). Cohen's Kappa statistics demonstrated good intermodality and interobserver agreement. 64-slice DSCT coronary angiography provides good image quality in patients with atrial fibrillation without the need for controlling the heart rate. DSCT can be used for ruling out significant stenosis in patients with atrial fibrillation with its high NPV for detecting in important stenosis.

  11. Diagnostic accuracy of dual-source CT coronary angiography in a population unselected for degree of coronary artery calcification and without heart rate modification

    Energy Technology Data Exchange (ETDEWEB)

    Lin, C.-J., E-mail: bcjlin@gmail.co [Department of Medical Imaging, Far Eastern Memorial Hospital, Pan-Chiao, Taiwan (China); National Yang-Ming University School of Medicine, Taipei, Taiwan (China); National Taiwan University College of Medicine, Taipei, Taiwan (China); Hsu, J.-C. [National Yang-Ming University School of Medicine, Taipei, Taiwan (China); Division of Cardiovascular Medicine, Far Eastern Memorial Hospital, Pan-Chiao City, Taiwan (China); National Taiwan University College of Medicine, Taipei, Taiwan (China); Lai, Y.-J. [Department of Medical Imaging, Far Eastern Memorial Hospital, Pan-Chiao, Taiwan (China); National Yang-Ming University School of Medicine, Taipei, Taiwan (China); National Taiwan University College of Medicine, Taipei, Taiwan (China); Wang, K.-L. [Department of Medical Imaging, Far Eastern Memorial Hospital, Pan-Chiao, Taiwan (China); Department of Radiological Technology, Yuanpei University, Taiwan (China); National Taiwan University College of Medicine, Taipei, Taiwan (China); Lee, J.-Y. [Department of Medical Imaging, Far Eastern Memorial Hospital, Pan-Chiao, Taiwan (China); National Taiwan University College of Medicine, Taipei, Taiwan (China); Li, A.-H. [Division of Cardiovascular Medicine, Far Eastern Memorial Hospital, Pan-Chiao City, Taiwan (China); National Taiwan University College of Medicine, Taipei, Taiwan (China); Chu, S.-H. [Division of Cardiovascular Surgery, Cardiovascular Center, Far Eastern Memorial Hospital, Pan-Chiao City, Taiwan (China); National Taiwan University College of Medicine, Taipei, Taiwan (China)

    2010-02-15

    Aim: To assess the ability of coronary angiography performed using dual-source computed tomography (DSCT) to evaluate coronary artery disease (CAD) in a population with unselected heart rates and extensive coronary calcification. Materials and methods: Forty-four patients at intermediate to high risk for CAD underwent both DSCT coronary angiography and invasive coronary angiography (ICA) within 30 days. No beta blockers were administered prior to imaging. Image quality and quantitatively stenosis of all coronary segments with a diameter >=1.5 mm were accessed. Patients were stratified according to mean heart rate (<70 versus >=70 bpm) and heart rate variability (<10 versus >=10 bpm). DSCT detection of coronary stenosis by segment, vessel, and patient characteristics were compared to the reference standard of ICA. Results: Diagnostic accuracy for all patients was high regarding sensitivity (97%), positive predictive value (PPV, 84.2%), and negative predictive value (NPV, 83.3%) but low regarding specificity (45.5%) with a moderate interobserver agreement (Kappa = 0.50). The accuracy for vessel-based diagnosis was high regarding sensitivity (96.6%), specificity (80.8%), PPV (80.3%), and NPV (96.7%). The segment-based diagnostic results revealed a moderate interobserver agreement for image quality and sensitivity, specificity, PPV and NPV for all segments of 66.9, 97.8, 90.8, and 89.9%, respectively. Conclusion: DSCT coronary angiography has high diagnostic accuracy in assessing CAD among patients at intermediate to high risk without using heart rate-modulating premedication. DSCT is not superior to ICA for diagnosis of calcified segments.

  12. 双源CT对泌尿系结石成分的定性诊断价值评价%The valuation of dual source CT for diagnosis of urinary stone composi-tion

    Institute of Scientific and Technical Information of China (English)

    马海鸿; 周应恩; 赵波

    2015-01-01

    Objective To investigate the diagnostic value of dual source CT on urinary stone constituents qualitative,aims to improve the correct diagnosis rate and the clinical curative effect. Methods Selected 53 patients with suspected urinary calculi hospitalized because of abdominal pain in our hospital from August 2014 to December 2014, 53 patients with suspected urinary calculi treated with dual source CT scan, stone composition, compared with stone infrared spectrum analysis results after the operation were analyzed. Results Dual source CT showed a total of 42 cases patients with gallstone,89 stones,postoperative infrared spectroscopy confirmed that a total of 35 cases of gallstone patients,a total of 66 star stone. There were stone of 8 components, mainly oxalic acid calculi, 30 patients, 59(89.4%) stones;followed by uric acid calculi in 3 cases,4(6.2%),2 cases of other stones 3(4.4%). Dual source CT showed containing calcium oxalate stone 76,accounting for all the stones of the 85.4%(76/89),spectrum proved that the 59(77.6%). Du-al energy that contain calcium oxalate (59/62) with accuracy of 95.2%, sensitivity 100%, specificity 61.0%(36/59),and negative predictive value of 100%. Pure calcium oxalate(20/59)with accuracy of 38.9%,sensitivity of 100%,and negative predictive value of 100%. Conclusion Using dual source CT in diagnosis of urinary calculi in the analysis of the composition of the stones in the body, good accuracy, and can better distinguish the different components of the stone,make the qualitative judgment, in order to provide evidence for clinical treatment. In the group of patients with oxalate stones up to about 90%,different from previous research,analysis may be related to regional,national,differ-ences in diet,pending further study.%目的:探讨双源CT对泌尿系结石成分定性的诊断价值,旨在提高临床诊断的正确率,改善患者的临床疗效。方法选取我院2014年8~12月间因腹痛怀疑

  13. Machine-learning based comparison of CT-perfusion maps and dual energy CT for pancreatic tumor detection

    Science.gov (United States)

    Goetz, Michael; Skornitzke, Stephan; Weber, Christian; Fritz, Franziska; Mayer, Philipp; Koell, Marco; Stiller, Wolfram; Maier-Hein, Klaus H.

    2016-03-01

    Perfusion CT is well-suited for diagnosis of pancreatic tumors but tends to be associated with a high radiation exposure. Dual-energy CT (DECT) might be an alternative to perfusion CT, offering correlating contrasts while being acquired at lower radiation doses. While previous studies compared intensities of Dual Energy iodine maps and CT-perfusion maps, no study has assessed the combined discriminative power of all information that can be generated from an acquisition of both functional imaging methods. We therefore propose the use of a machine learning algorithm for assessing the amount of information that becomes available by the combination of multiple images. For this, we train a classifier on both imaging methods, using a new approach that allows us to train only from small regions of interests (ROIs). This makes our study comparable to other - ROI-based analysis - and still allows comparing the ability of both classifiers to discriminate between healthy and tumorous tissue. We were able to train classifiers that yield DICE scores over 80% with both imaging methods. This indicates that Dual Energy Iodine maps might be used for diagnosis of pancreatic tumors instead of Perfusion CT, although the detection rate is lower. We also present tumor risk maps that visualize possible tumorous areas in an intuitive way and can be used during diagnosis as an additional information source.

  14. Low-dose prospectively electrocardiogram-gated axial dual-source CT angiography in patients with pulsatile bilateral bidirectional Glenn Shunt: an alternative noninvasive method for postoperative morphological estimation.

    Directory of Open Access Journals (Sweden)

    Xiaopeng Ji

    Full Text Available OBJECTIVE: To explore the clinical value of low-dose prospectively electrocardiogram-gated axial dual-source CT angiography (low-dose PGA scanning, CTA in patients with pulsatile bilateral bidirectional Glenn shunt (bBDG as an alternative noninvasive method for postoperative morphological estimation. METHODS: Twenty patients with pulsatile bBDG (mean age 4.2±1.6 years underwent both low-dose PGA scanning and conventional cardiac angiography (CCA for the morphological changes. The morphological evaluation included the anatomy of superior vena cava (SVC and pulmonary artery (PA, the anastomotic location, thrombosis, aorto-pulmonary collateral circulation, pulmonary arteriovenous malformations, etc. Objective and subjective image quality was assessed. Bland-Altman analysis and linear regression analyses were used to evaluate the correlation on measurements between CTA and CCA. Effective radiation dose of both modalities was calculated. RESULTS: The CT attenuation value of bilateral SVC and PA was higher than 300 HU. The average subjective image quality score was 4.05±0.69. The morphology of bilateral SVC and PA was displayed completely and intuitively by CTA images. There were 24 SVC above PA and 15 SVC beside PA. Thrombosis was found in 1 patient. Collateral vessels were detected in 13 patients. No pulmonary arteriovenous malformation was found in our study. A strong correlation (R2>0.8, P0.The mean effective dose of CTA and CCA was 0.50±0.17 mSv and 4.85±1.34 mSv respectively. CONCLUSION: CT angiography with a low-dose PGA scanning is an accurate and reliable noninvasive examination in the assessment of morphological changes in patients with pulsatile bBDG.

  15. The culprit lesion and its consequences: combined visualization of the coronary arteries and delayed myocardial enhancement in dual-source CT: a pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Mahnken, Andreas H.; Bruners, Philipp [RWTH Aachen University, Department of Diagnostic Radiology, University Hospital, Aachen (Germany); RWTH Aachen University, Applied Medical Engineering, Helmholtz Institute, Aachen (Germany); Friman, Ola; Hennemuth, Anja [Fraunhofer MEVIS, Bremen (Germany)

    2010-12-15

    To assess combined analysis of coronary arteries and delayed myocardial contrast enhancement based on co-registration of coronary CT angiography and late-phase CT and automatic segmentation. Co-registration and late enhancement segmentation were applied to coronary CT angiography and late-phase CT images from six pigs with acute myocardial infarction (MI) and six patients with chronic MI. MI size was quantified by manual delineation, the established 3SD method, and a new mixture model approach. Correspondence between coronary artery lesions and MI was assessed visually from fused segmentation results. Co-registration was successful in all cases. There was substantial agreement in the number of segments diagnosed with MI, comparing manual delineation and the mixture model for animal ({kappa} = 0.839) and patient studies ({kappa} = 0.770). There were no significant differences between the two methods (P > 0.05). In patients there was a discrepancy between the segmental distribution of MI and empirical coronary artery perfusion in 10/96 segments when compared with the true coronary branching pattern. The mixture model approach is well suited for automated assessment of MI size from late-phase cardiac CT. Fusion imaging eliminates the need for empirical knowledge of the anatomical relationship between the coronary artery lesion and the area of myocardial ischaemia. (orig.)

  16. 双源双能量CT对新疆南疆地区儿童输尿管结石的诊断价值%The Value of Dual-source Dual-energy CT in the Diagnosis of Ureteral Cal-culi in Children in Southern Xinjiang

    Institute of Scientific and Technical Information of China (English)

    马依迪丽·尼加提; 田序伟

    2015-01-01

    Objective To explore the application value of low-dose dual-source dual-energy CT in the diagnosis of urinary tract stones in children. Methods This study will explore the dual energy CT technology in southern xinjiang xinjiang regional chil-dren's disease diagnosis and differential diagnosis of ureteral calculi application value, and the image quality, the signal-to-noise ratio, lesion detection rate and identify differences, evaluate the feasibility of its application in clinical, 56 children cases CT in-spection and ultrasonic inspection group, analysis between the two groups statistically for difficult diagnosis of ureteral calculi. Results The dual source CT dual energy diagnosis of 56 cases of ureteral calculi children, all cases by ultrasound, including 1 case of abdominal segment, 3 cases of basin section, 2 cases of multiple ultrasound was not diagnosed or missed diagnosis of ureteral calculi. CT in the diagnosis of 47 cases with kidney seeper, 14 patients with moderately severe water, 9 cases with merger of urinary tract infection, 2 cases of diagnosis of urinary tuberculosis, 1 case of neurogenic bladder. Conclusion Low-dose CT in the diagnosis of dual energy not diagnosed with routine inspection method and its complications, complications were found very good diagnostic value.%目的:双源双能量低剂量CT在诊断儿童泌尿系结石中的应用价值。方法该研究将探究采用双能量CT技术在新疆南疆地区儿童输尿管结石疾病诊断和鉴别诊断的意义,然后比较其图像质量、信噪比、病变检出率这几方面,分析其在临床诊断中的可行性,将56例儿童病例分CT检查组及超声检查组,分析两组间对于难诊断型输尿管结石的统计学差异。结果双源双能量CT诊断输尿管结石儿童56例,所有病例均经过B超检查,其中1例腹段、3例盆段、2例多发输尿管结石B超未诊出或漏诊;CT诊断47例有肾积水、其中14例伴有中重度积水,9

  17. Dual energy perfusion imaging using dual source CT in the diagnosis and clinical application of pulmonary embolism%双源CT双能量肺灌注成像对肺栓塞的诊断和临床应用价值

    Institute of Scientific and Technical Information of China (English)

    周运锋; 史河水; 崔立明; 蒋日峰; 李欣; 刘永华; 韩萍

    2012-01-01

    Objective:To investigate the value of dual energy pulmonary perfusion imaging using dual source CT in the diagnosis and clinical application of pulmonary artery embolism (PE). Methods: Seventy-eight consecutive patients suspected of having PE underwent CT pulmonary arteriography with dual-energy technique on a dual source CT scanner. CT pulmonary arteriography (CTPA) and perfusion blood volume (PBV) images after post-processing of the raw data were obtained. Evaluation of the PBV image quality and typing of PE were performed by two radiologists as well as to observe the presence,location,extent of PE. The PBV appearances and its relationship with CTA images as well as pulmonary parenchyma abnormities were analyzed. The consistency of the 2 observers in evaluating the PBV image quality and typing were examined by Kappa value. The sensitivity,specificity,positive predictive value (PPV) and negative predictive value (NPV) of PBV images for the diagnosis of PE were calculated. Results:The ranking of PBV image quality and typing showed very good agreement between two observers,the K value was 0. 87 and 0. 80, respectively (Pdual energy pulmonary perfusion imaging on dual source CT.%目的:探讨双源CT双能量肺灌注成像对肺动脉栓塞的诊断和临床应用价值.方法:对疑诊肺动脉栓塞的78名患者行双源CT肺动脉成像双能量扫描,数据经后处理得到肺动脉血管图像(CTA)和肺灌注图像(PBV).两位医师对PBV图像进行质量评价和分型,同时观察CTA图像有无栓塞以及栓塞的部位、程度.分析PBV图像的表现与CTA图像、肺部异常改变的关系.用Kappa系数检验两

  18. 双源CT脑血管成像在颅内动脉瘤早期诊断中的应用%Application of dual-source CT angiography in the early diagnosis of intracranial aneurysms

    Institute of Scientific and Technical Information of China (English)

    耿云平

    2014-01-01

    目的 通过分析蛛网膜下腔出血(SAH)患者早期双源CT脑血管造影(CTA)的结果,探讨双源CT在颅内动脉瘤早期诊断中的应用.方法 对78例蛛网膜下腔出血患者行CTA检查,通过外科开颅夹闭术或DSA介入栓塞术等治疗.结果 78例CTA检查阳性70例,可疑6例,阴性2例.对可疑6例及阴性2例行DSA复查,结果确诊动脉瘤6例,阴性2例,假阳性及假阴性各2例.结论 CTA是一种快速、无创、可靠、简便的方法,能早期诊断动脉瘤,并能基本提供临床医生开颅行动脉瘤夹闭手术所需的影像学资料;对小动脉瘤的诊断尚需DSA检查进一步证实.%Objective By analyzing the early dual-source CT angiography of patients with subarachnoid hemorrhage (SAH),to study the application of dual-source CT in the early diagnosis of intracranial aneurysms.Methods Seventy-eight cases of subarachnoid hemorrhage underwent CTA,by the surgical clipping treatment or DSA intervention.Results Among the 78 cases,CTA positive in 70 cases,suspicious in 6 cases,2 cases were negative.The 6 suspicious patients and 2 negative patients underwent DSA review,6 cases were aneurysm,2 cases were negative,false positive and false negative cases were all 2 cases.Conclusions CTA is a fast,noninvasive,simple,reliable method,it can diagnose aneurysm earlier,basically it can provide the imaging datas of the surgical clipping operation required; the diagnosis of small aneurysms still need further confirmation by DSA examination.

  19. Dual energy CT myelography after lumba osteosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Grams, A.E.; Gizewski, E.R. [Medical Univ. Innsbruck (Austria). Dept. of Neuroradiology; Sender, J.; Obert, M. [Univ. Hospital Giessen (Germany). Dept. of Neuroradiology; Mortiz, R.; Krombach, G.A. [Univ. Hospital Giessen (Germany). Dept. of Radiology; Stein, M. [Univ. Hospital Giessen (Germany). Dept. of Neurosurgery; Oertel, M. [Vogtland-Klinikum Plauen (Germany). Dept. of Neurosurgery; Schmidt, T. [Klinikum Wuppertal (Germany). Dept. of Neuroradiology

    2014-07-15

    The purpose of this study was to evaluate the benefits of CT myelography in the DE technique in patients with lumbar osteosynthesis. In 30 patients a DE-CT scan of the spine with tube voltages of 80 kV and 140 kV was performed and a virtual monochromatic series of 120 kV was generated after intrathecal contrast injection. The impact of metal artifacts on the spinal canal and the spinal foramina was evaluated. The visualization of nerve roots was compared between a VRT series of the dural sac and conventional myelography. With tube voltages of 140 kV, the artifacts were least pronounced. As no overlay disturbance was present, VRT visualization of the nerve roots was more reliable than conventional myelography. In patients after osteosynthesis, CT in the DE technique provides minimal artifact disturbance using a tube voltage of 140 kV. ''Virtual myelography'' seems to be superior to conventional myelography for the evaluation of nerve roots. This could reduce additional conventional radiography, may shorten the entire examination and radiation time and diminish unnecessary painful movements for the patient.

  20. Evaluation of image quality and radiation dose of thoracic and coronary dual-source CT in 110 infants with congenital heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Saad, Moez Ben; Rohnean, Adela; Sigal-Cinqualbre, Anne; Adler, Ghazal; Paul, Jean-Francois [CC Marie Lannelongue, Radiology Department, Plessis-Robinson (France)

    2009-07-15

    There are only a few reports on the diagnostic accuracy, and the technical and clinical feasibility, of multidetector CT (MDCT) in infants with congenital heart disease (CHD). To evaluate the image quality and radiation dose of DSCT in babies with CHD. From November 2006 to November 2007, 110 consecutive infants with CHD referred for pre- or postoperative CT evaluation were included. All these infants had a spiral angiothoracic DSCT scan after injection of 300 mg/ml iopromide at 0.5-1 ml/s with a power injector using a low-dose protocol (80 kVp and 10 mAs/kg). Of these infants, 34 also underwent an ECG-gated coronary CT scan for evaluation of the course of the coronary arteries. No serious adverse events were recorded. The mean dose-length product was 8{+-}6 mGy.cm (effective dose 0.5{+-}0.2 mSv) and 21{+-}9 mGy.cm (effective dose 1.3{+-}0.6 mSv) during the non-ECG-gated spiral acquisition and ECG-gated acquisition, respectively. Diagnostic quality images were achieved with the spiral acquisition in 89% of cases. Compared to the spiral mode, ECG-gated acquisition significantly improved the visualization of the coronary arteries, with a diagnostic rate of 91% and 84% for the left and right coronary arteries, respectively. DSCT together with iopromide at 300 mg/ml is a valuable tool for the routine clinical evaluation of infants with CHD. ECG-gated acquisition provides reliable visualization of the course of the coronary arteries. (orig.)

  1. Application values of dual-source CT spectral imaging in the diagnosis of solitary pulmonary nodules%双源CT 能谱成像技术在肺内孤立性结节良恶性鉴别诊断的应用价值

    Institute of Scientific and Technical Information of China (English)

    曾炳亮; 李滋聪; 廖小清; 廖凤翔

    2016-01-01

    Objective To explore the diagnosis and differential diagnosis values of spectral imaging of dual-source CT in soli-tary pulmonary nodules. Methods Total of 82 patients with solitary pulmonary nodules (41 cases of benign pulmonary nodules and 41 cases of malignant pulmonary nodules),confirmed by pathology,underwent dual-source CT routine enhanced and dual energy enhancement scanning,and the corresponding CT values and iodine content were measured. The t test was performed to assess the statistical differences,which was definited with P<0.05. Results The CT value of routine enhanced was lower than that of iodine value chart both in arterial phase and venous phase,but the difference was statistically significant only in venous phase (P<0.001). The malignant group had lower normalized iodine concentration (NIC) than benign group ,the difference was statistically significant (P<0.05). Further ROC curve showed that the NIC had a high degree of sensitivity and specificity in the differential diagnosis be-tween benign and malignant pulmonary nodules. Both groups showed a continuous decline trend from 40keV to 140keV. The dif-ference in CT value was statistically significant both in arterial phase and venous phase between groups(P<0.05). Conclusion The spectral imaging of dual-source CT has great clinical value in the differential diagnosis between benign and malignant pulmonary nodules.%目的:探讨双源CT能谱成像技术对肺内良、恶性肿块鉴别诊断能力。方法回顾性分析经病理证实的82例肺内孤立性肿块(恶性肿瘤及良性肿块各41例)的常规CT增强及双源CT增强动、静脉期资料,记录各期CT值及碘含量。组间行t检验,以P<0.05为结果具有显著差异。结果无论是动脉期还是静脉期,常规增强的CT值均低于碘基图,差异仅在静脉期具有统计学意义(P<0.001)。恶性组标准化平均碘浓度含量低于良性组,组间差异有统计学意义(P<0.05),ROC曲线其

  2. Compare and Research the Radiation dose and Image Quality on Dual Energy Dual Source Spiral CT Pulmonary Artery Imaging%双源双能量螺旋CT肺动脉成像辐射剂量与图像质量的对比研究

    Institute of Scientific and Technical Information of China (English)

    张筱双

    2015-01-01

    Objective To compare the difference of the radiation dose and image quality on dual energy dual source spiral CT pulmonary artery imaging.Methods 80 cases of pulmonary embolism patients in our hospital were selected as the research object. All patients were willing to accept CTPA examination, 40 cases in each group. A group used tube voltage 80/Sn140KV check, B group used tube voltage 100/Sn140KV examination, compared two groups’ pulmonary artery, pulmonary artery, the dorsal fat CT value, other indicators and CT image treatment subjective evaluation, calculation of signal to noise ratio (SNR), contrast to noise ratio (CNR) and effective dose (ED).Results The average CT value of A group’s pulmonary artery, mean CNR index were signiifcantly higher than those of group B(P<0.05), subjective CT image quality evaluation results show score were not signiifcantly different between A group and B group, but ed level of group A was signiifcantly lower than that of group B(P<0.05).Conclusion Dual source dual energy CT pulmonary artery imaging using scanning 80/Sn140 kV has high value in the diagnosis of CT images at the same time, and can greatly reduce the radiation dose during examination, which has clinical application and popularization value.%目的:对比第二代双源双能量螺旋CT肺动脉成像(CTPA)不同辐射剂量下CT图像质量的差异性。方法筛选我院收治的肺栓塞患者80例,作为研究对象。所有患者均自愿接受CTPA检查,每组40例,其中A组管电压80/Sn140KV检查,B组管电压100/Sn140KV检查,比较两组患者肺动脉主干、肺动脉段、背部脂肪CT值等指标,并对CT影像治疗进行主观评分,计算信噪比(SNR)、对比噪声比(CNR)、有效剂量(ED)等。结果 A组患者肺动脉平均CT值、平均CNR指标明显高于B组(P<0.05),主观CT影像质量评价结果显示A组与B组评分无显著差异,但A组ED水平明显低于B组(P<0.05)。结论

  3. Dual-time FDG-PET/CT in patients with potential breast cancer recurrence

    DEFF Research Database (Denmark)

    Baun, Christina; Falch Braas, Kirsten; Gerke, Oke;

    Dual-time FDG-PET/CT in patients with potential breast cancer recurrence: head-to-head comparison with CT and bonescintigraphy......Dual-time FDG-PET/CT in patients with potential breast cancer recurrence: head-to-head comparison with CT and bonescintigraphy...

  4. Osteitis: a retrospective feasibility study comparing single-source dual-energy CT to MRI in selected patients with suspected acute gout

    Energy Technology Data Exchange (ETDEWEB)

    Diekhoff, Torsten [Humboldt-Universitaet zu Berlin, Freie Universitaet Berlin, Department of Radiology, Charite - Universitaetsmedizin Berlin Campus Mitte, Berlin (Germany); Charite - Universitaetsmedizin Berlin, Department of Radiology (CCM), Berlin (Germany); Scheel, Michael; Hamm, Bernd; Hermann, Kay-Geert A. [Humboldt-Universitaet zu Berlin, Freie Universitaet Berlin, Department of Radiology, Charite - Universitaetsmedizin Berlin Campus Mitte, Berlin (Germany); Hermann, Sandra [Charite - Universitaetsmedizin Berlin Campus Mitte, Department of Rheumatology and Clinical Immunology, Berlin (Germany); Mews, Juergen [Toshiba Medical Systems Europe, BV, Zoetermeer (Netherlands)

    2017-02-15

    Dual-energy computed tomography detects tophi in patients with chronic gout. However, other information that can be obtained from the same scan is not the focus of the current research, e.g., the detection of bone marrow edema (BME) using virtual bone marrow imaging (VBMI). The aim of this study was to evaluate if BME in patients with acute arthritis can be detected with VBMI using magnetic resonance imaging (MRI) as the standard of reference. This retrospective study included 11 patients who underwent both MRI and dual-energy computed tomography (mean interval of 40 days). BME in MRI (standard of reference) and VBMI was judged independently by two different blinded readers. φ-correlation coefficient and Cohen's κ were performed for statistical analysis. Approval was waived by the IRB. Two patients with a final diagnosis of RA and one with septic arthritis showed osteitis on MRI and VBMI. However, in each case, there were individual bones identified with osteitis on MRI but not VBMI. Three additional patients with the final diagnosis of RA were identified correctly as negative for BME. There was a good correlation between both modalities (φ = 0.8; κ = 0.8). Inter-rater reliability was excellent for both modalities (κ = 0.9). We have shown that detecting osteitis using VBMI is feasible in patients with inflammatory arthritis. Further studies are needed on larger, more-targeted populations to better define the indications, accuracy, and added value of this technique. (orig.)

  5. Dual-Energy CT of Rectal Cancer Specimens

    DEFF Research Database (Denmark)

    Al-Najami, Issam; Beets-Tan, Regina G H; Madsen, Gunvor

    2016-01-01

    BACKGROUND: An accurate method to assess malignant lymph nodes in the mesorectum is needed. Dual-energy CT scans simultaneously with 2 levels of energy and thereby provides information about tissue composition based on the known effective Z value of different tissues. Each point investigated...... is represented by a certain effective Z value, which allows for information on its composition. OBJECTIVE: We wanted to standardize a method for dual-energy scanning of rectal specimens to evaluate the sensitivity and specificity of benign versus malignant lymph node differentiation. Histopathological evaluation...... cancer. MAIN OUTCOME MEASURES: We measured accuracy of differentiating benign from malignant lymph nodes by investigating the following: 1) gadolinium, iodine, and water concentrations in lymph nodes; 2) dual-energy ratio; 3) dual-energy index; and 4) effective Z value. RESULTS: Optimal discriminations...

  6. 双源CT双能量肺动脉血管成像技术早期诊断肺动脉栓塞患者的实效性评价%The Effectiveness of Dual-source Dual-energy CT Pulmonary Angiography of the Early Diagnosis of Patients with Pulmonary Embolism

    Institute of Scientific and Technical Information of China (English)

    李卫星; 姚菁菁

    2015-01-01

    Objective To investigate the effectiveness of dual-source dual-energy CT pulmonary angiography of the early diagnosis of patients with pulmonary embolism. Methods 40 patients with suspicious pulmonary disease were chosen in our hospital to receive treatment. All patients are dual-source dual-energy CT scan lung machine, with dual-energy scan data evaluation software were analyzed and the lungs into upper, middle and lower, the energy imaging were analyzed. MPR, MIP, VR, CTVE technology to reconstruct the original data were used. Results In 40 patients, 18 patients were diagnosed with pulmonary embolism, pneumonia in 4 patients, 3 patients with lung cancer, 15 patients with normal. 18 cases of patients with pulmonary embolism, a total of 218 emboli, which of central emboli 90, eccentric 46, mural-type 42, type 40 totally were occluded. 15 normal patients, their lung tissue perfusion were analyzed, the upper lungs and lungs, middle and lower comparative analysis, the difference was not statistically significant (t= 1.149,1.021,1.027,1.135, P> 0.05). The normal lung tissue perfusion and pulmonary embolism were analyzed, the upper lungs and lungs, middle and lower comparative analysis, the difference was not statistically significant (t = 6.394,6.092,6.607,6.862, P <0.05). Conclusion Dual-source dual-energy CT pulmonary angiography for the diagnosis of pulmonary embolism in patients has a very important sense and the ability to detect the disease at an early stage of pulmonary embolism, so it is worthy of promotion.%目的:探讨双源CT双能量肺动脉血管成像技术早期诊断肺动脉栓塞患者的实效性评价,为临床提供参考。方法选择我院2013年1月至2014年3月收治的40例可疑肺栓塞疾病患者,所有患者均以双源CT机进行肺部双能量扫描,扫描数据以双能量的评估软件分析,肺部分成上、中、下,进行能量成像分析。采用MPR、MIP、VR、CTVE技术对原始数据进行重建。结果40

  7. Feasibility study of dual-source CT high-pitch aorta angiography%双源CT大螺距模式主动脉成像的可行性研究

    Institute of Scientific and Technical Information of China (English)

    王利军; 孙凯; 王志琴; 董馨; 贾海亮; 杜晓辉; 张皓成

    2014-01-01

    Objective: To investigate the feasibility, image quality and radiation dose for high-pitch dual-source CT angiography (CTA) of the whole aorta. Methods: Each group of 62 and 58 patients underwent CTA either on dual-source CT device with high-pitch mode with a pitch of 3.2(group A) or conventional single-source (group B). Evaluate the image quality and radiation dose. Image quality of the aorta was independently assessed by two readers. Scanner-reported dose-length product values were used to estimate effective dose values. Results:Subjective scoring of image quality were significantly increased in the high-pitch examination protocol (2.66±0.51 vs.2.14±0.47, P<0.01) for groups A and B. Objective scoring of image quality were not significantly different. The imaging length was not significantly different, but the imaging time was significantly shorter in the high-pitch group (1.61±0.23 vs.6.52±1.41s P<0.01) for groups A and B. Radiation dose was lower. (3.97±1.07 mSv vs. 15.18±2.58 mSv, P<0.01). Conclusion:High-pitch dual-source CT angiography of the whole aorta is feasible in unselected patients. As a significant advantage over regular pitch protocols, shorter scan time, lower radiation dose and less motion artifacts is possible. this CT mode bears potential to become a standard CT protocol.%目的:利用双源CT的大螺距模式对主动脉全程扫描成像,对照评价其图像质量和有效辐射剂量,旨在研究双源CT大螺距模式行主动脉全程扫描的可行性。方法:将接受主动脉CT血管造影(CTA)的患者随机分为A、B两组,A组62例,B组58例。A组使用大螺距扫描模式,B组使用常规扫描模式;图像质量评价分客观和主观两种方法,客观评价包括图像噪声及信噪比,主观评价由2名放射科医生独立完成。辐射剂量统计使用设备自带的数据记录。结果:大螺距模式主观图像质量评分(2.66±0.51)较常规扫描组(2.14±0.47)高

  8. Value of dual source CT iodine concentration in the evaluation of pathological grades of esophageal carcinoma%双源CT强化程度与食管癌病理分级的关系

    Institute of Scientific and Technical Information of China (English)

    刘小静; 周胜利; 苗重昌

    2016-01-01

    目的:探讨双源CT碘浓度评估食管癌病理分级的价值。方法回顾性分析经内镜或手术病理证实的60例食管癌患者,其中病理分级为高分化癌17例、中分化癌24例、低分化癌19例。60例均行食管双源CT双能量平扫及双期增强扫描,测量计算食管癌病灶动脉期标准化碘浓度(NIC)、静脉期NIC、动脉期病灶强化程度和静脉期强化程度。采用单因素方差分析比较不同病理分级食管癌患者间NIC及强化程度的差异,采用ROC曲线评价NIC及强化程度鉴别中、高分化食管癌与低分化食管癌的效能。结果高、中、低级别食管癌患者的动脉期NIC值分别为(1.54±0.34)、(1.72±0.50)、(2.10±0.40)mg/ml,静脉期NIC值分别为(1.55±0.52)、(1.80±0.62)、(2.18±0.35)mg/ml,静脉期强化程度分别为(25.65±4.43)、(27.55±6.82)、(30.77±6.38)HU,各组间差异均有统计学意义(P均<0.05);高、中、低级别食管癌患者的动脉期强化程度分别为(14.40±3.91)、(14.26±7.35)、(16.17±6.89) HU,差异无统计学意义(P=0.582)。动脉期NIC、静脉期NIC和静脉期强化程度鉴别中、高分化食管癌与低分化食管癌的ROC下面积分别为0.801、0.817和0.730。结论双源CT测定碘浓度评估食管癌病理分级有一定价值。%Objective To investigate the value of dual source CT iodine concentration in the assessment of pathological grade of esophageal carcinoma. Methods Retrospective review was performed on 60 cases with pathologically⁃confirmed esophageal carcinoma. Among them, 17 tumors were well differentiated, 24 were moderately differentiated and 19 were poorly differentiated. The dual⁃energy plain scan and double phase enhanced scan of dual⁃source CT were performed on all 60 cases. Normalized iodine concentration (NIC) and the enhancement degree of the esophageal carcinoma in the arterial and venous phase were

  9. 双源CT双能量碘图对急性坏死性胰腺炎影像的诊断价值%The Value of Dual-source Dual-energy CT with Iodine Overlay in the Diagnosis of Acute Necrotizing Pancreatitis

    Institute of Scientific and Technical Information of China (English)

    袁元; 黄子星; 李真林; 宋彬; 邓莉萍

    2012-01-01

    Objective To investigate the clinical value of dual-source computed tomography dual-energy Iodine overlay technique in the imaging diagnosis of acute necrotizing pancreatitis. Methods The imaging data were retrospectively analyzed in 67 cases of acute necrotizing pancreatitis underwent contrast-enhanced dual-source dual-energy CT in portal venous phase. The CT imaging parameters, including the difference of CT value between pancreatic parenchyma and necrotic lesion, contrast-to-noise ratio of pancreatic parenchyma-to-necrosis, area of pancreatic necrosis and score of subjective diagnosis, were measured and assessed on CT images of 80 kV, 140 kV, weighted-average 120 kV as well as Iodine overlay. Results The differences of CT value between pancreatic parenchyma and necrosis in the images of 80 kV, 140 kV, weighted-average 120 kV and Iodine overlay were (67. 40 ±20.82) HU,(42. 87±14. 99) HU, (48. 69±15. 82) HU, (33. 01 ± 10. 26) HU, respectively;contrast-to-noise ratios of pancreatic parenchyma-to-necrosis of each group were 8. 36 ± 3. 58, 5. 85±2. 65, 7. 68±3. 51, 10. 60± 4. 34;area of pancreatic necrosis of each group was (3. 78 ±2. 68) cm2, (3.28 ± 2.59) cm2, (3. 37±2. 46) cm2, (2. 42 ± 1. 98) cm2 ;the score of subjective diagnosis of each group was 3. 88 ±0. 33, 3. 31 ± 0. 80, 3. 58 ±0. 66, 2. 81 ± 0. 76, respectively. The four indexes in the images of Iodine overlay were significantly different from those of another three groups (P<0. 05). Contrast-to-noise ratio of pancreatic parenchyma-to-necrosis in the images of Iodine overlay was significantly higher than that of another three groups, while the difference of CT value, area of pancreatic necrosis and score of subjective diagnosis were lower. Conclusion Dual-source CT dual-energy Iodine overlay is not helpful to improve subjective judgment in the diagnosis of pancreatic necrosis, but contributes to the display of hypoperfusion area around the necrosis.%目的 初步探讨双源CT双能量碘

  10. 基于Random Walks算法的心脏双源CT左心房分割%Study of left atrium segmentation in dual source CT image with random walks algorithms

    Institute of Scientific and Technical Information of China (English)

    何昌保; 马秀丽; 余长明

    2016-01-01

    For dual source CT image with contrast media,due to heart soft tissue density and contrast media uneven distribution result in the CT value of heart tissues uneven and boundary fuzzy,taking a single image segmentation algorithm is too difficult to obtain satisfactory results,so morphological reconstruction and random walks hybrid method is proposed in this paper.Firstly,we used morphological reconstruction operation on image smoothing filtering, which makes the heart cavity gray information convergence and gray level differences with the surrounding tissue and get the left atrium area with the fuzzy boundary;Then the random walks algorithm sets the seed points for each region of the image,and gives the weight of each side,and takes the weight of the edge as the transfer probability.For each unlabeled point is calculated from the point of first arrival probability of seed points.Finally,according to the first hit probability to choose the maximum that a class as belonging to the class,attribute of the unlabeled points and finally get the accurate left atrial.%针对在传统的CT介入式治疗过程中,胸腔中软组织较多软组织的厚度和注射的造影剂在心脏中呈现的不均匀分布,导致在采用CT成像的图像中胸腔内部各组织之间存在边界模糊或者确实等状况,本文提出一种采用形态重构和随机行走相结合的分割方法。首先利用形态学开闭运算对图像进行化简,并使得心脏 CT腔体边界分离,进而使得各个组织组织分离,再结合Random walks算法。从而使得不需要标记太多种子点的情况下提高了分割的速度和准确性,实验证明该方法能够达到预期的目标。

  11. CORONARY ANGIOGRAPHY WITH DUAL SOURCE COMPUTED TOMOGRAPHY: INITIAL EXPERIENCE

    Institute of Scientific and Technical Information of China (English)

    Zhu-hua Zhang; Wen-min Zhao; Wen-bin Mou; Li-ren Zhang; Wen-ling Zhu; Qi Miao; Qi Fang; Zheng-yu Jin; Shu-yang Zhang; Song-bai Lin; Dong-jing Li; Ling-yan Kong; Yi-ning Wang; Lan Song; Yun Wang

    2007-01-01

    To explore the scan technique and image quality of coronary angiography with dual source computed tomography (CT) without oral metoprolol preparation.Methods Plain and enhanced dual source CT coronary angiography without oral metoprolol preparation was prospectively performed in 600 patients. Calcium scoring with plain scan images as well as multi-planar reconstruction( MPR ), maximum intensity projection (MIP), and volume rendering technique (VRT) reconstruction with enhanced scan images were performed in all cases. The scan technique and post-reconstruction experience was summarized. The image quality was classified as 1 to 4 points, and coronary segments classified according to the American Heart Association standards were evaluated.Results The average calcium score of the 600 cases was 213.6 ± 298.7 (0-3 216. 5). The average heart rate of the enhanced scan was 82.1 ± 16.2 (47-139) bpm. The post-reconstruction methods with which coronary segments could be shown as best as possible consisted of single phase reconstruction method, two or more phases supplemented method, and electrocardiogram editing method. Altogether 8 457 coronary segments were evaluated, among which 97.2% were evaluated as point 1, 1.7% point 2, 0.5% point 3, and0.6% point 4. The coronary segments in 261 cases were completely normal, while 360 segments were diagnosed with < 50% stenosis and 625 segments with ≥50%stenosis.Conclusions Excellent coronary artery image can be obtained with dual source CT in patients with any heart rate without oral metoprolol preparation. Heart rate is not a major source of the artifact, coronary segments can be well shown with single or multiple-phase reconstruction method.

  12. 双源双能量CT评价兔VX2移植瘤介入术疗效的实验研究%The laboratory research of dual-source and dual-energy CT in evaluating the effect of rabbit VX2 tumor interventional therapy

    Institute of Scientific and Technical Information of China (English)

    祁克信; 劳群; 贾玉柱

    2013-01-01

    Objective To explore the diagnostic value of the dual-energy technique with dual-source in the evaluation of therapeutic effect of interventional therapy for hepatocarcinoma.Methods 8 rabbits with tumor growing well were treated with intervention operation,paralleled with double energy CT scan and focal area image,CT and color order change were measured by dual energy liver OVERLAY workstation.Meanwhile,The necrosis and survival of tumor were evaluated by dual energy CT after hepatocarcinoma intervention therapy.Results Taking pathologic diagnosis as gold standard,compared with imaging and pathological results in the order of black,red,orange and red,accuracies were 87.2%,72.3%,71.5% and 83.6% respectively.Sensitivities were 95.1%,37.4%,54.7% and 63.8% respectively.Specificities were 85.4%,86.3%,81.5% and 85.8% respectively.Positive predictives value were 61.4%,54.2%,62.4% and 55.6% respectively.Negative predictive values were 96.3%,76.2%,79.7% and 91.3 % respectively.According to the Spearman relevance analysis,there was strong positive correlation between survival of tumor cells and image color scale (r =12.35,P < 0.05).Conclusion The necrosis and survival of tumor cells in rabbit VX2 liver tumor model can be preliminarily reflected by dual source CT dual energy enhancement scanning.The results provide good reference to the application of dual-source and dual-energy in clinical diagnosis and treatment.%目的 探讨双源双能量CT评价肝癌介入治疗疗效的价值.方法 8只生长良好的荷瘤兔,行介入手术,并进行双源双能量CT扫描,利用双源工作站OVERLAY信息图像,测量病灶区CT值,并记录其色阶变化,探讨双能量CT在肝癌介入治疗后肿瘤存活与坏死情况.结果 以全部的病理诊断为金标准,经过病理和影像对照分析,按黑色、暗红色、红色、橘红色顺序,色阶准确度分别为87.2%、72.3%、71.5%、83.6%,敏感度分别为95.1

  13. High-pitch dual-source CT pulmonary angiography in naturally breathing patients%自然呼吸下高螺距双源CT肺动脉造影方法探讨

    Institute of Scientific and Technical Information of China (English)

    邓国辉; 胡红杰; 张文明; 陈彬; 胡吉波

    2015-01-01

    目的探讨自然呼吸状态下高螺距双源CT肺血管造影(CTPA)技术对可疑肺栓塞患者应用的可行性、影像质量。方法对54例临床疑似肺动脉栓塞的患者(高螺距组),采用第二代双源CT行CT肺血管造影(CTPA),患者在自然呼吸下行高螺距CTPA检查(螺距为3.0,120kV,100mAs,50ml对比剂);另选前期检查患者54例作为常规组行常规CTPA检查(螺距为0.8,120kV,100mAs,80ml对比剂),深吸气后屏气扫描。记录PA强化程度、图像噪声、信噪比、图像的整体质量、扫描范围内肺动脉分支是否存在对比剂充盈不均和心脏、呼吸运动伪影以及辐射剂量,结果进行统计学分析。结果高螺距组肺动脉主干(PT)及尖段(S1)肺动脉、后基底段(S10)肺动脉的平均 CT值为(404±104)、(453±119)和(453±119)HU,平均图像背景噪声(11±2)HU,平均检查时间为(0.67±0.09)s,平均辐射剂量为(142±31)mGy cm,明显优于常规组(P<0.05)。检查图像无呼吸及心脏的运动伪影。肺动脉分支未见完全或部分缺损,所有患者均达到诊断要求。结论自然呼吸下状态高螺距双源CTPA检查能得到较高质量的图像,没有产生呼吸和心脏的运动伪影,且可避免出现瓦氏(Valsalva)呼吸所致的伪影。%Objective To assess the feasibility and image quality of high- pitch dual- source CT pulmonary angiography (CTPA) in natural y breathing patients with suspected pulmonary embolism. Methods One hundred and eight patients with clin-ically suspected pulmonary embolism underwent CTPA examination with dual- source CT scanner. Patients were randomly divid-ed into 2 groups:patients in high- pitch group (n=54) received high- pitch CTPA (pitch 3.0, 120 kV, 100 mAs, 50ml contrast ma-terial) without special breathing requirement, patients in routine group (n=54) received normal mode CTPA (pitch 0.8, 120 kV, 100 m

  14. The value of dual-source dual-energy CT angiography in the diagnosis of carotid artery stenosis%双能量颈部CT血管成像诊断颈动脉狭窄性病变的价值

    Institute of Scientific and Technical Information of China (English)

    郑玲; 周长圣; 赵艳娥; 张龙江; 李敏; 刘德志; 卢光明

    2011-01-01

    Objective Carotid artery stenosis is one of the important causes of ischemic cerebrovascular diseases, for which angiography remains a chief diagnostic option. Dual-source dual-energy CT, as a newly developed technique, has its unique superiority in angiography, but reports have not seen on its application to the diagnosis of carotid artery stenosis. The authors evaluated dual-source dual-energy CT angiography ( CTA) in the diagnosis of carotid artery stenosis by comparing it with digital subtraction angiography ( DSA). Methods Forty patients first underwent dual-source dual-energy CTA and then DSA of the carotid artery within two weeks. The carotid artery was classified into common carotid artery, extracranial internal carotid artery and intracranial internal carotid artery. Carotid stenosis was rated as mild ( ≤29% ) , moderate (30% -69% ) , severe (70% - 99% ) and occlusion ( 100% ) in the analyses of CTA and DSA images. The sensitivity, specificity, accuracy, PPV and NPV of CTA in the diagnosis of carotid artery stenosis were calculated with DSA as the reference standard. Results Of 240 vessel segments in 40 patients, CTA displayed 70 with various de- grees of stenosis (mild; n = 35, moderate; n = 25, and severe; n = 10) and 170 normal segments, while DSA exhibited 75 with various degrees of stenosis (mild; n = 38, moderate; n = 24, and severe; n = 13) and 165 normal segments. With DSA as the reference standard, the sensitivity, specificity, accuracy, PPV and NPV of CTA in the detection of carotid artery stenosis were 92.0% (69/75) , 99. 4% (164/165), 97.1% (233/240), 98.6% (69/70), and 96. 5% (164/170), respectively. Conclusion Dual-source dual-energy CTA has a high sensitivity in the detection of carotid artery stenosis, which can be used in the screening and diagnosis of carotid artery stenosis as a routine modality.%目的 颈动脉狭窄是缺血性脑血管疾病发病的重要原因之一,目前,临床仍采用常规血管造影的方法对该病进

  15. Application Value of Dual-source CT Low-dose Scanning in the Diagnosis of Adenoidal Hypertrophy in Children%双源CT低剂量扫描在诊断儿童腺样体肥大中的应用价值

    Institute of Scientific and Technical Information of China (English)

    王守玺

    2014-01-01

    Objective To evaluate and analyze the application value of dual-source CT low-dose scanning in the diagnosis of ade-noidal hypertrophy in children, so as to provide reliable reference for future clinical diagnostic work. Methods 76 cases of children clinically diagnosed as adenoidal hypertrophy admitted in our hospital from January, 2011 to December, 2013 were extracted. And they were divided into the control group and the observation group in accordance with the order of admission. The control group was given dual-source CT conventional-dose scanning, and the observation group was given dual-source CT low-dose scanning, the image quality, radiation dose and diagnostic results of both groups were compared and analyzed. Results There was no signifi-cant difference in the result of nasopharyngeal anatomy display between the observation group and the control group ( P>0.05), but the difference in adenoid CT value and radiation dose between the two groups was significant (P0.05),两组患儿腺样体CT值和辐射剂量比较存在差异有统计学意义(P<0.05)。结论经双源CT低剂量扫描可对儿童腺样体肥大做出准确的诊断,且其安全性较常规剂量扫描更高,临床诊断价值显著,值得关注并推广。

  16. Quantitative dual energy CT measurements in rabbit VX2 liver tumors: Comparison to perfusion CT measurements and histopathological findings

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Long Jiang, E-mail: kevinzhanglongjiang@yahoo.com.cn [Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, 305 Zhongshan East Road, Xuanwu District, Nangjing, Jiangsu Province 210002 (China); Wu, Shengyong, E-mail: cjr.wushengyong@vip.163.com [Institute of Tianjin Medical Imaging, Tianjin 300192 (China); Wang, Mei, E-mail: 281406196@qq.com [Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, 305 Zhongshan East Road, Xuanwu District, Nangjing, Jiangsu Province 210002 (China); Lu, Li, E-mail: xuzhoululi@163.com [Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, 305 Zhongshan East Road, Xuanwu District, Nangjing, Jiangsu Province 210002 (China); Chen, Bo, E-mail: chenbo1985@yahoo.com.cn [Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, 305 Zhongshan East Road, Xuanwu District, Nangjing, Jiangsu Province 210002 (China); Jin, Lixin, E-mail: lixin.jin@siemens.com [Siemens Healthcare, MR Collaboration NE Asia, Shanghai (China); Wang, Jiandong, E-mail: jdwang1216@163.com [Department of Pathology, Jinling Hospital, Clinical School of Medical College, Nanjing University, 305 Zhongshan East Road, Xuanwu District, Nangjing, Jiangsu Province 200012 (China); Larson, Andrew C., E-mail: a-larson@northwestern.edu [Department of Radiology, Northwestern University, Chicago, IL (United States); Lu, Guang Ming, E-mail: cjr.luguangming@vip.163.com [Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, 305 Zhongshan East Road, Xuanwu District, Nangjing, Jiangsu Province 210002 (China)

    2012-08-15

    Purpose: To evaluate the correlation between quantitative dual energy CT and perfusion CT measurements in rabbit VX2 liver tumors. Materials and methods: This study was approved by the institutional animal care and use committee at our institution. Nine rabbits with VX2 liver tumors underwent contrast-enhanced dual energy CT and perfusion CT. CT attenuation for the tumors and normal liver parenchyma and tumor-to-liver ratio were obtained at the 140 kVp, 80 kVp, average weighted images and dual energy CT iodine maps. Quantitative parameters for the viable tumor and adjacent liver were measured with perfusion CT. The correlation between the enhancement values of the tumor in iodine maps and perfusion CT parameters of each tumor was analyzed. Radiation dose from dual energy CT and perfusion CT was measured. Results: Enhancement values for the tumor were higher than that for normal liver parenchyma at the hepatic arterial phase (P < 0.05). The highest tumor-to-liver ratio was obtained in hepatic arterial phase iodine map. Hepatic blood flow of the tumor was higher than that for adjacent liver (P < 0.05). Enhancement values of hepatic tumors in the iodine maps positively correlated with permeability of capillary vessel surface (r = 0.913, P < 0.001), hepatic blood flow (r = 0.512, P = 0.010), and hepatic blood volume (r = 0.464, P = 0.022) at the hepatic arterial phases. The effective radiation dose from perfusion CT was higher than that from DECT (P < 0.001). Conclusions: The enhancement values for viable tumor tissues measured in iodine maps were well correlated to perfusion CT measurements in rabbit VX2 liver tumors. Compared with perfusion CT, dual energy CT of the liver required a lower radiation dose.

  17. Dual-energy CT for detection of endoleaks after endovascular abdominal aneurysm repair: usefulness of colored iodine overlay.

    Science.gov (United States)

    Ascenti, Giorgio; Mazziotti, Silvio; Lamberto, Salvatore; Bottari, Antonio; Caloggero, Simona; Racchiusa, Sergio; Mileto, Achille; Scribano, Emanuele

    2011-06-01

    The purpose of our study was to evaluate the value of dual-source dual-energy CT with colored iodine overlay for detection of endoleaks after endovascular abdominal aortic aneurysm repair. We also calculated the potential dose reduction by using a dual-energy CT single-phase protocol. From November 2007 to November 2009, 74 patients underwent CT angiography 2-7 days after endovascular repair during single-energy unenhanced and dual-energy venous phases. By using dual-energy software, the iodine overlay was superimposed on venous phase images with different percentages ranging between 0 (virtual unenhanced images) and 50-75% to show the iodine in an orange color. Two blinded readers evaluated the data for diagnosis of endoleaks during standard unenhanced and venous phase images (session 1, standard of reference) and virtual unenhanced and venous phase images with colored iodine overlay images (session 2). We compared the effective dose radiation of a single-energy biphasic protocol with that of a single-phase dual-energy protocol. The diagnostic accuracy of session 2 was calculated. The mean dual-energy effective dose was 7.27 mSv. By using a dual-energy single-phase protocol, we obtained a mean dose reduction of 28% with respect to a single-energy biphasic protocol. The diagnostic accuracy of session 2 was: 100% sensitivity, 100% specificity, 100% negative predictive value, and 100% positive predictive value. Statistically significant differences in the level of confidence for endoleak detection between the two sessions were found by reviewers for scores 3-5. Dual-energy CT with colored iodine overlay is a useful diagnostic tool in endoleak detection. The use of a dual-energy single-phase study protocol will lower radiation exposure to patients.

  18. Exploiting dual otoacoustic emission sources

    Science.gov (United States)

    Abdala, Carolina; Kalluri, Radha

    2015-12-01

    Two distinct processes generate otoacoustic emissions (OAEs). Reflection-source emissions, here recorded as stimulus frequency OAEs, are optimally informative at low sound levels and are more sensitive to slight hearing loss; they have been linked to cochlear amplifier gain and tuning. Distortion-source emissions are strongest at moderate-high sound levels and persist despite mild hearing loss; they likely originate in the nonlinear process of hair cell transduction. In this preliminary study, we exploit the unique features of each by generating a combined reflection-distortion OAE profile in normal hearing and hearing-impaired ears. Distortion-product (DP) and stimulus-frequency (SF) OAEs were recorded over a broad range of stimulus levels and frequencies. Individual I/O and transfer functions were generated for both emission types in each ear, and OAE peak strength, compression threshold, and rate of compression were calculated. These combined SFOAE and DPOAE features in normal and hearing-impaired ears may provide a potentially informative and novel index of hearing loss. This is an initial step toward utilizing OAE source in characterizing cochlear function and dysfunction.

  19. Exploiting Dual Otoacoustic Emission Sources

    Science.gov (United States)

    Abdala, Carolina; Kalluri, Radha

    2016-01-01

    Two distinct processes generate otoacoustic emissions (OAEs). Reflection-source emissions, here recorded as stimulus frequency OAEs, are optimally informative at low sound levels and are more sensitive to slight hearing loss; they have been linked to cochlear amplifier gain and tuning. Distortion-source emissions are strongest at moderate-high sound levels and persist despite mild hearing loss; they likely originate in the nonlinear process of hair cell transduction. In this preliminary study, we exploit the unique features of each by generating a combined reflection-distortion OAE profile in normal hearing and hearing-impaired ears. Distortion-product (DP) and stimulus-frequency (SF) OAEs were recorded over a broad range of stimulus levels and frequencies. Individual I/O and transfer functions were generated for both emission types in each ear, and OAE peak strength, compression threshold, and rate of compression were calculated. These combined SFOAE and DPOAE features in normal and hearing-impaired ears may provide a potentially informative and novel index of hearing loss. This is an initial step toward utilizing OAE source in characterizing cochlear function and dysfunction. PMID:27695142

  20. 心电编辑对提高双源CT冠脉图像质量的初步研究%Preliminary application of ECG-editing technique in improving image quality of dual-source CT coronary angiography

    Institute of Scientific and Technical Information of China (English)

    杨立民; 刘成磊; 徐凯

    2012-01-01

    目的:探讨心电编辑在改善双源CT冠脉图像质量中的作用.方法:以冠脉分支为单位,回顾性分析60例心率变异过大或心律失常患者双源CT冠脉成像编辑前后的图像质量,总结不同类型的心电编辑方法.结果:60例心率变异过大或心律失常患者,心率范围为55~269次/min,平均心率(92.8±31.9)次/min,冠脉图像编辑前后的图像质量总评分分别为2.26±1.03、3.5±0.61(t=-17.85,P=0.001);表明编辑前后图像质量的评分有统计学意义,编辑后图像质量明显改善.结论:心电编辑技术可以明显改善心率变异过大或心律失常患者双源CT冠脉成像的图像质量.%Objective:To evaluate the effect of ECG-editing technique on dual-source CT coronary angiography. Methods: Based on per-segment analysis, image quality before and after ECG editing were retrospectively analyzed in 60 patients with heart rate variability or arrhythmia. Different types of ECG editing methods were summarized. Results:In 60 patients without stable sinus rhythm,the heart rate was (55~269) bpm/min. And mean heart rate was (92. 8±31. 9) bpm/min. The over all mean image quality scores before and after ECG editing were (2. 26±1. 03) and (3. 50±0. 61), respectively. There was statistical difference in pre-editing and post-editing reconstructed images quality, suggesting ECG editing significantly improving the image quality ( P <0. 01). Conclusion: ECG editing technique significantly improves image quality of coronary artery in patients with heart rate variability or arrhythmia.

  1. Prospectively Electrocardiogram-Gated High-Pitch Spiral Acquisition Mode Dual-Source CT Coronary Angiography in Patients with High Heart Rates: Comparison with Retrospective Electrocardiogram-Gated Spiral Acquisition Mode

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Kai; Ma, Rui; Wang, Li Jun [Dept. of Radiology, Baotou Central Hospital, Baotou (China); Li, Li Gang; Chen, Jiu Hong [CT BM Clinic Marketing, Siemens Healthcare, Beijing (China)

    2012-11-15

    To assess the image quality and effective radiation dose of prospectively electrocardiogram (ECG)-gated high-pitch spiral acquisition mode (flash mode) of dual-source CT (DSCT) coronary angiography (CTCA) in patients with high heart rates (HRs) as compared with retrospectively ECG-gated spiral acquisition mode. Two hundred and sixty-eight consecutive patients (132 female, mean age: 55 {+-} 11 years) with mean HR > 65 beats per minute (bpm) were prospectively included in this study. The patients were divided into two groups. Collection was performed in group A CTCA using flash mode setting at 20-30% of the R-R interval, and retrospectively ECG-gated spiral acquisition mode in group B. The image noise, contrast-to-noise ratio (CNR), image quality scores, effective radiation dose and influencing factors on image quality between the two groups were assessed. There were no significant differences in image quality scores and proportions of non-diagnostic coronary artery segments between two groups (image quality scores: 1.064 {+-} 0.306 [group A] vs. 1.084 {+-} 0.327 [group B], p = 0.063; proportion of non-diagnostic coronary artery segments: segment-based analysis 1.52% (group A) vs. 1.74% (group B), p = 0.345; patient-based analysis 7.5% (group A) vs. 6.7% (group B), p = 0.812). The estimated radiation dose was 1.0 {+-} 0.16 mSv in group A and 7.1 {+-} 1.05 mSv in group B (p = 0.001). In conclusion, in patients with HRs > 65 bpm without cardiac arrhythmia, the prospectively high-pitch spiral-acquisition mode with image-acquired timing set at 20-30% of the R-R interval provides a similar image quality and low rate of non-diagnostic coronary segments to the retrospectively ECG-gated low-pitch spiral acquisition mode, with significant reduction of radiation exposure.

  2. Dual Source CT Angiography in Diagnosis and Treatment for Aneurvsms of Willis Circle%双源CT血管成像在Willis环区动脉瘤诊断及治疗中的应用

    Institute of Scientific and Technical Information of China (English)

    沈国鑫; 庾君毅; 史跃; 王安明

    2011-01-01

    目的:探讨双源CT血管成像(DSCTA)在Willis环区动脉瘤的诊断、分型及介入栓塞治疗中的临床应用价值.方法:术前采用DSCTA检查筛选颅内动脉瘤患者26例(33个).采用Seldinger技术,在DSA引导下行全脑血管造影,了解动脉瘤位置、形态、大小,测量瘤颈及瘤体直径;再根据不同的解剖学形态选用不同的介入栓塞方法治疗.结果:术前DSCAT和DSA检查对颅内动脉瘤的大小、位置、形状显示一致.26例患者共33个动脉瘤均成功栓塞,完全栓塞18个,占54.54%;栓塞程度在95%以上12个,占36.36%;不完全栓塞3个,占9.09%.结论:DSCTA检查和DSA全脑血管检查可提供颅内动脉瘤的位置、形态、大小等影像解剖学资料,为动脉瘤的临床分类和治疗方法的选择提供依据.%Objective: To evaluate the clinical value of dual source CT angiography (DSCTA) in the diagnosis, classification and interventional embolisation treatment for aneurysm of Willis circle.Methods:26cases with intracranial aneurysms were screened in preoperation by DSCTA.Preoperative cerebral angiography under the guidance of the DSA was used by the Seldinger technique, the analysis and research of the information could be assisted to comprehend the location, shape, size of aneurysm, the diameter of aneurysm neck and body was measured, then appropriate interventional therapy was selected according to different anatomical patterns.Results :33 intracranial aneurysms in 26 patients were successfully embolized.Complete embolism was achieved in 18 cases (54.54%), embolismed over 95% in 12 (36.36%), partial embolism in 3 aneurysms( 9.09% ).Conclusions:Preoperative examination by DSCTA and DSA can provide the basis for aneurysm treatment, reduce blindness and shorten the treatment time.

  3. Bachmann束及其血供的双源CT冠状动脉成像表现%Imaging findings of Bachmann bundle and its arterial supply on dual-source CT coronary angiography

    Institute of Scientific and Technical Information of China (English)

    彭泽华; 蒲红; 白林; 印隆林; 陈加源; 蒋瑾; 李刚

    2011-01-01

    Objective To investigate the morphologic features of Bachmann bundle (BB) and its vascular supply on dual-source CT coronary angiography(DSCTCA) in healthy volunteers and patients with coronary artery lesion (CAL). Methods Clinical histories, electrocardiograms (ECGs), and images of DSCTCA of 106 patients ( CAL group) and 100 healthy volunteers ( Control group) were reviewed. All 106 patients underwent conventional coronary angiography ( CCA ). The Gensini scoring system was used to assess the results of CCA. The patients were divided into three groups according to their Gensini scores. The length, width and superoinferior diameter, CT value, and vascular supply of BB were studied. Rank sum test for continuous variables and Chi-square test for categorical variables were used in statistical analysis.Results ( 1 ) BB visualization rate of control group was higher than CAL group [86.0% (86/100) vs 51.9%(55/106), x2 = 27.726, P < 0.01]. The higher the Gensini score of CAL subgroup, the lower the visualization rate of its BB [80.0% ( 28/35 ), 55.6% ( 20/36 ), 20.0% ( 7/35 ), x2 = 25.530, P < 0.01].(2)The median of measurements of length,width and superoinferior diameter of control and CAL group were 13.0 vs 13.8,5.0 vs 5.2 and 5.9 vs 6.2 mm, respectively ( P > 0.05 ). (3) The CT value of the BB region in control group( median :42.6 HU ) was higher than that of CAL group( median: 13.0 HU) ( Z = - 7.061, P <0.01). The CT values of BB regions in patients with nonvisualized BB (median: -16.0 HU) were lower. The CT values of the BB regions in CAL group were negatively-correlated with Gensini scores( median:19.0) (r = -0.553, P <0.01 ). (4)The blood supply of BB and BB region was provided by right sinuatrial node artery ( SNA, 58.7%, 121/206 ), left SNA ( 35.9%, 74/206 ) or both SNAs ( 5.3%, 11/206 ).Conclusions DSCTCA could can show the anatomical characteristics of BB and its arterial supply. The serious the degree of CAL , the lower the BB display rate, and the

  4. Dual source and dual detector arrays tetrahedron beam computed tomography for image guided radiotherapy

    Science.gov (United States)

    Kim, Joshua; Lu, Weiguo; Zhang, Tiezhi

    2014-02-01

    Cone-beam computed tomography (CBCT) is an important online imaging modality for image guided radiotherapy. But suboptimal image quality and the lack of a real-time stereoscopic imaging function limit its implementation in advanced treatment techniques, such as online adaptive and 4D radiotherapy. Tetrahedron beam computed tomography (TBCT) is a novel online imaging modality designed to improve on the image quality provided by CBCT. TBCT geometry is flexible, and multiple detector and source arrays can be used for different applications. In this paper, we describe a novel dual source-dual detector TBCT system that is specially designed for LINAC radiation treatment machines. The imaging system is positioned in-line with the MV beam and is composed of two linear array x-ray sources mounted aside the electrical portal imaging device and two linear arrays of x-ray detectors mounted below the machine head. The detector and x-ray source arrays are orthogonal to each other, and each pair of source and detector arrays forms a tetrahedral volume. Four planer images can be obtained from different view angles at each gantry position at a frame rate as high as 20 frames per second. The overlapped regions provide a stereoscopic field of view of approximately 10-15 cm. With a half gantry rotation, a volumetric CT image can be reconstructed having a 45 cm field of view. Due to the scatter rejecting design of the TBCT geometry, the system can potentially produce high quality 2D and 3D images with less radiation exposure. The design of the dual source-dual detector system is described, and preliminary results of studies performed on numerical phantoms and simulated patient data are presented.

  5. Dual source and dual detector arrays tetrahedron beam computed tomography for image guided radiotherapy.

    Science.gov (United States)

    Kim, Joshua; Lu, Weiguo; Zhang, Tiezhi

    2014-02-01

    Cone-beam computed tomography (CBCT) is an important online imaging modality for image guided radiotherapy. But suboptimal image quality and the lack of a real-time stereoscopic imaging function limit its implementation in advanced treatment techniques, such as online adaptive and 4D radiotherapy. Tetrahedron beam computed tomography (TBCT) is a novel online imaging modality designed to improve on the image quality provided by CBCT. TBCT geometry is flexible, and multiple detector and source arrays can be used for different applications. In this paper, we describe a novel dual source-dual detector TBCT system that is specially designed for LINAC radiation treatment machines. The imaging system is positioned in-line with the MV beam and is composed of two linear array x-ray sources mounted aside the electrical portal imaging device and two linear arrays of x-ray detectors mounted below the machine head. The detector and x-ray source arrays are orthogonal to each other, and each pair of source and detector arrays forms a tetrahedral volume. Four planer images can be obtained from different view angles at each gantry position at a frame rate as high as 20 frames per second. The overlapped regions provide a stereoscopic field of view of approximately 10-15 cm. With a half gantry rotation, a volumetric CT image can be reconstructed having a 45 cm field of view. Due to the scatter rejecting design of the TBCT geometry, the system can potentially produce high quality 2D and 3D images with less radiation exposure. The design of the dual source-dual detector system is described, and preliminary results of studies performed on numerical phantoms and simulated patient data are presented.

  6. Dual-energy perfusion-CT in recurrent pancreatic cancer. Preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Fritz, F.; Skornitzke, S.; Kauczor, H.U.; Stiller, W.; Klauss, M. [Heidelberg Univ. (Germany). Clinic of Diagnostic and Interventional Radiology; Hackert, T. [Heidelberg Univ. (Germany). Clinic of Surgery; Grenacher, L. [Diagnostik Muenchen (Germany). Diagnostic Imaging Center

    2016-06-15

    To evaluate the diagnostic performance of dual energy (DE) perfusion-CT for the differentiation between postoperative soft-tissue formation and tumor recurrence in patients after potentially curative pancreatic cancer resection. 24 patients with postoperative soft-tissue formation in the conventional regular follow-up CT acquisition after pancreatic cancer resection with curative intent were included prospectively. They were examined with a 64-row dual-source CT using a dynamic sequence of 34 DE acquisitions every 1.5 s (80 ml of iodinated contrast material, 370 mg/ml, flow rate 5 ml/s). Weighted average (linearly blended M0.5) 120 kVp-equivalent dual-energy perfusion image data sets were evaluated with a body-perfusion CT tool for estimating blood flow, permeability, and blood volume. Diagnosis was confirmed by histological study (n=4) and by regular follow-up. Final diagnosis was local recurrence of pancreatic cancer in 15 patients and unspecific postoperative tissue formation in 9 patients. The blood-flow values for recurrence tissue trended to be lower compared to postoperative tissue formation with 16.6 ml/100 ml/min and 24.7 ml/100 ml/min, respectively for weighted average 120 kVp-equivalent image data, which was not significant (n.s.) (p=0.06, significance level 0.05). Permeability- and blood-volume values were only slightly lower in recurrence tissue (n.s.). DE perfusion-CT is feasible in patients after pancreatic cancer resection and a promising functional imaging technique. As only a trend for lower perfusion values in local recurrence compared to unspecific postoperative alterations was found, the perfusion differences are not yet sufficient to differentiate between malignancy and unspecific postoperative alterations for this new technique. Further studies and technical improvements are needed to generate reliable data for this clinically highly relevant differentiation.

  7. Applied anatomy of myocardial bridge-mural coronary artery by dual-source CT%心肌桥-壁冠状动脉临床应用解剖的双源CT研究

    Institute of Scientific and Technical Information of China (English)

    虞康惠; 成官迅; 刘国顺; 阎静

    2012-01-01

    Objective To study the morphologic features of myocardial bridge-mural coronary (MB-MCA) by dual-source CT (DSCT), and improve the understanding of it on clinical diagnosis value. Methods 3709 patients were involved in this study. MB-MCAs were located accurately according to the guideline of the American Heart Association, and the length, depth, compression of MB-MCA and concomitant atheromatous changes were evaluated. Results 638 cases had MB-MCA in overall 3709 patients by DSCT, getting the prevalence of 17.20%. 654 MB-MCA were detected including 426 in segment 7, 72 in segment 8 and 56 in segment 6, the rest distributing in segment 2, 3, 4, 9, 11, 12,13 and 16. Of 654 MB-MCA, the mean length was (20.52± 9.84 )mm and the mean thickness was (1.27± 0.93 )mm. The lumen of MCA showed no significant stenosis or mild to moderate stenosis, and a rare severe stenosis. 92 patients with MB-MCA had atherosclerotic plaque. Conclusions DSCT not only may directly demonstrate the dissection shape of MB-MCA, but might also dynamically evaluate the change of MB-MCA in the entire cardiac cycle, supplying the clinical significance research of MB-MCA for valuable information.%目的 研究心肌桥-壁冠状动脉(MB-MCA)的双源CT(DSCT)形态学特征,以提高对MB-MCA临床诊断价值的认识.方法 分析3709例冠状动脉CTA病人,根据美国心脏病协会的冠状动脉16段分段法对检出的MB-MCA进行准确定位,对其长度、深度、收缩期管腔压缩程度及其伴随的粥样硬化情况进行评估.结果 3709例病人中发现MB-MCA 638例,检出率约17.20%,共检出654支MB-MCA,其中426支位于7段(S7)、72支位于8段(S8)、56支位于6段(S6),其余分别分布于2段(S2)、3段(S3)、4段(S4)、9段(S9)、11段(S11)、12段(S12)、13段(S13)及16段(S16);MB-MCA平均长度为( 20.52±9.84 )mm,平均深度为(1.27±0.93 )mm;收缩期时MCA管腔呈现不同程度的狭窄,但重度狭窄罕见;92例MB-MCA患者

  8. Single-source dual-energy CT angiography with reduced iodine load in patients referred for aortoiliofemoral evaluation before transcatheter aortic valve implantation: impact on image quality and radiation dose

    Energy Technology Data Exchange (ETDEWEB)

    Dubourg, Benjamin; Caudron, Jerome; Lefebvre, Valentin; Dacher, Jean-Nicolas [Rouen University Hospital, Department of Radiology, Rouen (France); UFR Medecine Pharmacie, INSERM U1096, Rouen (France); Lestrat, Jean-Pierre [Rouen University Hospital, Department of Radiology, Rouen (France); Bubenheim, Michael [Rouen University Hospital, Department of Biostatistics, Rouen (France); Godin, Matthieu; Tron, Christophe [Rouen University Hospital, Department of Cardiology, Rouen (France); Eltchaninoff, Helene; Bauer, Fabrice [Rouen University Hospital, Department of Cardiology, Rouen (France); UFR Medecine Pharmacie, INSERM U1096, Rouen (France)

    2014-11-15

    To compare image quality and radiation dose of pre-transcatheter aortic valve implantation (TAVI) aortoiliofemoral CT angiography (AICTA) provided by standard vs. dual-energy mode with reduced iodine load protocols. One hundred and sixty-one patients underwent a two-step CTA protocol before TAVI including cardiac CTA with injection of 65 mL of iodinated contrast agent (ICA), immediately followed by AICTA. From this second acquisition, the following three different patient groups were identified: Group 1: 52 patients with standard AICTA (60 mL ICA, 100 kVp, mA automodulation); Group 2: 48 patients with dual-energy AICTA with 50 % iodine load reduction (30 mL ICA, fast kVp switching, 600 mA); Group 3: 61 patients with an identical protocol to Group 2, but exposed to 375 mA. The qualitative/subjective image quality (13-point score) and quantitative/objective image quality (contrast attenuation and image noise) were evaluated. The radiation dose was recorded. There was no significant difference in non-diagnostic images between the three protocols. Contrast attenuation, signal-to-noise ratio and contrast-to-noise ratio were significantly higher, whereas noise was significantly lower in the standard protocol (all P < 0.05). The radiation dose was lower in the dual-energy protocol at 375 mA (P < 0.05). Dual-energy AICTA before TAVI results in a reduction of iodine load while maintaining sufficient diagnostic information despite increased noise. (orig.)

  9. A dual cone-beam CT system for image guided radiotherapy: Initial performance characterization

    Energy Technology Data Exchange (ETDEWEB)

    Li Hao; Bowsher, James; Yin Fangfang [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27710 (United States); Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States); Giles, William [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States)

    2013-02-15

    Purpose: The purpose of this study is to evaluate the performance of a recently developed benchtop dual cone-beam computed tomography (CBCT) system with two orthogonally placed tube/detector sets. Methods: The benchtop dual CBCT system consists of two orthogonally placed 40 Multiplication-Sign 30 cm flat-panel detectors and two conventional x-ray tubes with two individual high-voltage generators sharing the same rotational axis. The x-ray source to detector distance is 150 cm and x-ray source to rotational axis distance is 100 cm for both subsystems. The objects are scanned through 200 Degree-Sign of rotation. The dual CBCT system utilized 110 Degree-Sign of projection data from one detector and 90 Degree-Sign from the other while the two individual single CBCTs utilized 200 Degree-Sign data from each detector. The system performance was characterized in terms of uniformity, contrast, spatial resolution, noise power spectrum, and CT number linearity. The uniformities, within the axial slice and along the longitudinal direction, and noise power spectrum were assessed by scanning a water bucket; the contrast and CT number linearity were measured using the Catphan phantom; and the spatial resolution was evaluated using a tungsten wire phantom. A skull phantom and a ham were also scanned to provide qualitative evaluation of high- and low-contrast resolution. Each measurement was compared between dual and single CBCT systems. Results: Compared to single CBCT, the dual CBCT presented: (1) a decrease in uniformity by 1.9% in axial view and 1.1% in the longitudinal view, as averaged for four energies (80, 100, 125, and 150 kVp); (2) comparable or slightly better contrast (0{approx}25 HU) for low-contrast objects and comparable contrast for high-contrast objects; (3) comparable spatial resolution; (4) comparable CT number linearity with R{sup 2}{>=} 0.99 for all four tested energies; (5) lower noise power spectrum in magnitude. Dual CBCT images of the skull phantom and the

  10. Adenosine-stress dynamic real-time myocardial perfusion CT and adenosine-stress first-pass dual-energy myocardial perfusion CT for the assessment of acute chest pain: Initial results

    Energy Technology Data Exchange (ETDEWEB)

    Weininger, Markus [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Schoepf, U. Joseph, E-mail: schoepf@musc.edu [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Department of Medicine, Division of Cardiology, Medical University of South Carolina, Charleston, SC (United States); Ramachandra, Ashok [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Fink, Christian [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany); Rowe, Garrett W.; Costello, Philip [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Henzler, Thomas [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany)

    2012-12-15

    Purpose: Recent innovations in CT enable the evolution from mere morphologic imaging to dynamic and functional testing. We describe our initial experience performing myocardial stress perfusion CT in a clinical population with acute chest pain. Methods and materials: Myocardial stress perfusion CT was performed on twenty consecutive patients (15 men, 5 women; mean age 65 ± 8 years) who presented with acute chest pain and were clinically referred for stress/rest SPECT and cardiac MRI. Prior to CT each patient was randomly assigned either to Group A or to Group B in a consecutive order (10 patients per group). Group A underwent adenosine-stress dynamic real-time myocardial perfusion CT using a novel “shuttle” mode on a 2nd generation dual-source CT. Group B underwent adenosine-stress first-pass dual-energy myocardial perfusion CT using the same CT scanner in dual-energy mode. Two experienced observers visually analyzed all CT perfusion studies. CT findings were compared with MRI and SPECT. Results: In Group A 149/170 myocardial segments (88%) could be evaluated. Real-time perfusion CT (versus SPECT) had 86% (84%) sensitivity, 98% (92%) specificity, 94% (88%) positive predictive value, and 96% (92%) negative predictive value in comparison with perfusion MRI for the detection of myocardial perfusion defects. In Group B all myocardial segments were available for analysis. Compared with MRI, dual-energy myocardial perfusion CT (versus SPECT) had 93% (94%) sensitivity, 99% (98%) specificity, 92% (88%) positive predictive value, and 96% (94%) negative predictive value for detecting hypoperfused myocardial segments. Conclusion: Our results suggest the clinical feasibility of myocardial perfusion CT imaging in patients with acute chest pain. Compared to MRI and SPECT both, dynamic real-time perfusion CT and first-pass dual-energy perfusion CT showed good agreement for the detection of myocardial perfusion defects.

  11. Dual-energy CT (DECT) imaging of tophi and monosodium urate deposits in a patient with longstanding anorexia nervosa

    DEFF Research Database (Denmark)

    Weihe, Johan Petur; Birger Morillon, Melanie; Lambrechtsen, Jess

    Dual-energy CT (DECT) imaging of tophi and monosodium urate deposits in a patient with longstanding anorexia nervosa......Dual-energy CT (DECT) imaging of tophi and monosodium urate deposits in a patient with longstanding anorexia nervosa...

  12. Dual-energy CT (DECT) imaging of tophi and monosodium urate deposits in a patient with longstanding anorexia nervosa

    DEFF Research Database (Denmark)

    Weihe, Johan Petur; Birger Morillon, Melanie; Lambrechtsen, Jess

    Dual-energy CT (DECT) imaging of tophi and monosodium urate deposits in a patient with longstanding anorexia nervosa......Dual-energy CT (DECT) imaging of tophi and monosodium urate deposits in a patient with longstanding anorexia nervosa...

  13. Dual-energy CT (DECT) imaging of tophi and monosodium urate deposits in a patient with longstanding anorexia nervosa

    DEFF Research Database (Denmark)

    Weihe, Johan Petur; Birger Morillon, Melanie; Lambrechtsen, Jess;

    2014-01-01

    Dual-energy CT (DECT) imaging of tophi and monosodium urate deposits in a patient with longstanding anorexia nervosa......Dual-energy CT (DECT) imaging of tophi and monosodium urate deposits in a patient with longstanding anorexia nervosa...

  14. A simulation study on proton computed tomography (CT) stopping power accuracy using dual energy CT scans as benchmark

    DEFF Research Database (Denmark)

    Hansen, David Christoffer; Seco, Joao; Sørensen, Thomas Sangild

    2015-01-01

    Background. Accurate stopping power estimation is crucial for treatment planning in proton therapy, and the uncertainties in stopping power are currently the largest contributor to the employed dose margins. Dual energy x-ray computed tomography (CT) (clinically available) and proton CT (in...

  15. 胃左动脉参与肝细胞癌供血的双源CT血管成像研究%Evaluation of hepatocellular carcinoma supplied by the left gastric artery with dual-source CT angiography

    Institute of Scientific and Technical Information of China (English)

    陈光文; 涂诗琦; 陈加源; 赵黎明

    2012-01-01

    Objective:To investigate the incidence and influential factors of hepatocellular carcinoma (HCC) supplied by the left gastric artery. Methods:91 patients with HCC in left lobe were prospectively included in the study. Standardized dual source CT (DSCT) multi phases acquisition was performed for all patients. Thin slice source images were reconstruc ted using techniques ol multi planar reconstruction, curved planar reconstruction,maximum intensity projection and volume rendering to display the left gastric artery. The images were interpreted by three experienced abdominal radiologists. The in cidence of HCC fed by LGA and factors like the size, location, pseudocapsule of HCC lesions and previous history of transarterial chemoembolization (TACE) therapy were analyzed. Results:There were 23 (22. 1 %) cases supplied by LGA in 91 patients with a total of 104 HCC lesions,while 19 lesions were type macro mass compared with 4 lesions as type nodus, 22 lesions invaded Glisson capsule and 17 lesions had previous history of TACE therapy. All lesions had no unbroken pseud ocapsule. LGA participated in HCC blood supply by left lobe hepatic artery (n=3) and accessory left lobe hepatic artery (n=5) originated from LGA,as well as branch direct supplying the lesions (n=15). Conclusion:LGA is common extrahe patic collateral artery of left lobe HCC and the presence is significantly correlated with the tumor size,the location,the sta tus of pseudocapsule and history of TACE therapy of HCC lesion.%目的:探讨胃左动脉(LGA)参与肝细胞癌(HCC)供血的影响因素.方法:采用双源CT对91例左叶HCC患者进行血管成像扫描,采用MPR、CPR、MIP、VR等后处理技术重建LGA.分析LGA参与HCC供血与病灶大小、位置、假包膜的完整性及接受经导管动脉化疗栓塞(TACE)治疗的关系.结果:91例患者共计104个HCC病灶,23个病灶有LGA参与供血,发生率为22.1%.23个有LGA参与供血的HCC病灶中,19个为巨块型,4个为结节型,22

  16. Dual-source CT Low-dose Technology Used in Suspected Lesions in Patients with Chest CT Examination%双源CT低剂量技术在疑是胸部病变患者CT检查中的应用

    Institute of Scientific and Technical Information of China (English)

    刘素芝; 郭占林; 张颖

    2016-01-01

    目的:研究双源CT低剂量技术在疑是胸部病变患者CT检查中的应用价值。方法选取2013年11月至2014年11月来我院接受检查的161例疑是胸部病变患者,按照患者前来就诊的先后顺序将患者分为7组,每组23例,对7组患者分别采用常规管电流量110mAs和低管电流量105,100,95,90,85,80 mAs进行测量,比较各组患者肺动脉分叉平面肺动脉信噪比、肺动脉-竖脊肌对比噪声比、降主动脉信噪比、降主动脉-竖脊肌对比噪声比、图像主观质量评分及病变检出情况。结果随着放射剂量的降低,肺动脉和降主动脉的信噪比逐渐降低(P<0.05);各组图像质量评分随着球管电流量的减小而降低(P<0.05);80mAs低管电流量组病变检出率为81.25%较其余各组显著较低(P<0.05)。结论双源CT低剂量技术能在疑是胸部病变患者CT检查中给予准确判断,能有效降低放射对人体造成的伤害,建议行双源CT检查时采用85mAs的参考管电流量,既能获得准确清晰的诊断图像又能明显降低患者所受辐射剂量。%Objective to study the dual-source CT low-dose technology in the application of CT examination in patients with suspected chest lesions. Methods Selection in November 2013 to November 2014 in our hospital for inspection of 161 patients with suspected chest lesions, according to the order of patients in the hospital can be divided into 7 groups, each group of 23 cases, the 7 groups patients respectively using conventional pipe electricity flow 110 mAs and low electrical flow 105, 100, 95, 90, 85, 80 mAs measurement, comparison between groups in patients with pulmonary artery bifurcation plane the signal-to-noise ratio of pulmonary artery, pulmonary artery - sma vertical contrast to noise ratio, the descending aorta signal-to-noise ratio, the descending aorta-sma vertical contrast to noise ratio, the subjective image quality score and lesion detection

  17. 双源CT Flash扫描模式对复杂性先天性心脏病临床诊断价值研究%Study on Clinical Diagnostic Value for Diagnosing Complex Congenital Heart Disease with Flash Spiral Mode of Dual-source CT

    Institute of Scientific and Technical Information of China (English)

    肖红; 杨立; 刘艳

    2015-01-01

    目的 探讨双源CT Flash扫描模式应用于复杂性先天性心脏病的诊断价值.方法 对20例经手术证实的复杂先心病患者的心脏双源CT和超声心动图检查资料进行回顾性分析.结果 心脏内部畸形共41处,双源CT检出30处,超声心动图检出40处,两者诊断正确率分别为73.17%(30/41)和97.56%(40/41),差异具有统计学意义(x2=7.91,P=0.0049);心脏血管连接处畸形共有14处,双源CT检出13处,超声心动图检出12处,两者诊断正确率分别为92.86%(13/14)和85.71%(12/14),差异无统计学意义(x2=0.74,P=0.3875);心脏周围血管畸形41处,双源CT检出39处,超声心动图检出28处,两者诊断正确率分别为95.12%(39/41)和68.29%(28/41),差异具有统计学意义(x2=8.15,P=0.0042).全部畸形共96处,双源CT检出82处,正确率为85.42%,超声心动图检出80处,正确率为83.33%,两者比较差异无统计学意义(x2=0.15, P=0.6985).结论 双源CT对于先天性心脏病心脏周围血管部分畸形的诊断具有明显优势;对于整体诊断,双源CT和超声心动图的诊断能力没有明显差异.%Objective To evaluate the diagnostic value and surgery significance of dual-source CT Flash spiral model for diagnosing complex congenital heart disease. Methods Retrospectively analysis the 20 children with complex congenital heart disease, all of them were examined by the Flash CT and echocardiograph,and received surgical operation treatment. Results There were 41intracardiac deformities.30(73.17%) were detected by Flash CT and 40(97.56%) were detected by echocardiograph,a statistically significant difference between the diagnosis accuracy of Flash CT and echocardiograph (x2=7.91 ,P=0.0049). There were 14 heart-vessel conjunction deformities.13 (92.86%) were detected by Flash CT and 12 (85.71%) were detected by echocardiograph,their diagnosis accuracy had no difference (x2=0.74,P=0.3875).There were 41 great vessel deformities. 39 (95.12%) were detected by Flash CT and 28

  18. Correlation between Dual-Energy and Perfusion CT in Patients with Hepatocellular Carcinoma.

    Science.gov (United States)

    Gordic, Sonja; Puippe, Gilbert D; Krauss, Bernhard; Klotz, Ernst; Desbiolles, Lotus; Lesurtel, Mickaël; Müllhaupt, Beat; Pfammatter, Thomas; Alkadhi, Hatem

    2016-07-01

    Purpose To develop a dual-energy contrast media-enhanced computed tomographic (CT) protocol by using time-attenuation curves from previously acquired perfusion CT data and to evaluate prospectively the relationship between iodine enhancement metrics at dual-energy CT and perfusion CT parameters in patients with hepatocellular carcinoma (HCC). Materials and Methods Institutional review board and local ethics committee approval and written informed consent were obtained. The retrospective part of this study included the development of a dual-energy CT contrast-enhanced protocol to evaluate peak arterial enhancement of HCC in the liver on the basis of time-attenuation curves from previously acquired perfusion CT data in 20 patients. The prospective part of the study consisted of an intraindividual comparison of dual-energy CT and perfusion CT data in another 20 consecutive patients with HCC. Iodine density and iodine ratio (iodine attenuation of the lesion divided by iodine attenuation in the aorta) from dual-energy CT and arterial perfusion (AP), portal venous perfusion, and total perfusion (TP) from perfusion CT were compared. Pearson R and linear correlation coefficients were calculated for AP and iodine density, AP and iodine ratio, TP and iodine density, and TP and iodine ratio. Results The dual-energy CT protocol consisted of bolus tracking in the abdominal aorta (threshold, 150 HU; scan delay, 9 seconds). The strongest intraindividual correlations in HCCs were found between iodine density and AP (r = 0.75, P = .0001). Moderate correlations were found between iodine ratio and AP (r = 0.50, P = .023) and between iodine density and TP (r = 0.56, P = .011). No further significant correlations were found. The volume CT dose index (11.4 mGy) and dose-length product (228.0 mGy · cm) of dual-energy CT was lower than those of the arterial phase of perfusion CT (36.1 mGy and 682.3 mGy · cm, respectively). Conclusion A contrast-enhanced dual-energy CT protocol developed

  19. Dual-phase CT findings of groove pancreatitis

    Energy Technology Data Exchange (ETDEWEB)

    Zaheer, Atif, E-mail: azaheer1@jhmi.edu [The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD 21231 (United States); Pancreatitis Center, Division of Gastroenterology, Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD 21231 (United States); Haider, Maera, E-mail: mhaider3@jhmi.edu [The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD 21231 (United States); Kawamoto, Satomi, E-mail: skawamo1@jhmi.edu [The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD 21231 (United States); Hruban, Ralph H., E-mail: rhruban1@jhmi.edu [Department of Pathology, The Sol Goldman Pancreatic Cancer Research Center, the Johns Hopkins University School of Medicine, Baltimore, MD 21231 (United States); Fishman, Elliot K., E-mail: efishma1@jhmi.edu [The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD 21231 (United States)

    2014-08-15

    Purpose: Groove pancreatitis is a rare focal form of chronic pancreatitis that occurs in the pancreaticoduodenal groove between the major and minor papillae, duodenum and pancreatic head. Radiologic appearance and clinical presentation can result in suspicion of malignancy rendering pancreaticoduodenectomy inevitable. This study reports dual phase CT findings in a series of 12 patients with pathology proven groove pancreatitis. Materials and methods: Retrospective review of preoperative CT findings in 12 patients with histologically proven groove pancreatitis after pancreaticoduodenectomy. Size, location, attenuation, presence of mass or cystic components in the pancreas, groove and duodenum, calcifications, duodenal stenosis and ductal changes were recorded. Clinical data, laboratory values, endoscopic ultrasonographic and histopathological findings were collected. Results: Soft tissue thickening in the groove was seen in all patients. Pancreatic head, groove and duodenum were all involved in 75% patients. A discrete lesion in the pancreatic head was seen in half of the patients, most of which appeared hypodense on both arterial and venous phases. Cystic changes in pancreatic head were seen in 75% patients. Duodenal involvement was seen in 92% patients including wall thickening and cyst formation. The main pancreatic duct was dilated in 7 patients, with an abrupt cut off in 3 and a smooth tapering stricture in 4. Five patients had evidence of chronic pancreatitis with parenchymal calcifications. Conclusion: Presence of mass or soft tissue thickening in the groove with cystic duodenal thickening is highly suggestive of groove pancreatitis. Recognizing common radiological features may help in diagnosis and reduce suspicion of malignancy.

  20. Dual-energy CT angiography of the lung in patients with suspected pulmonary embolism. Initial results

    Energy Technology Data Exchange (ETDEWEB)

    Fink, C.; Michaely, H.J. [Inst. fuer Klinische Radiologie und Nuklearmedizin, Universitaetsklinikum Mannheim, Univ. Heidelberg (Germany); Inst. fuer Klinische Radiologie, Campus Grosshadern, Klinikum der Univ. Muenchen (Germany); Johnson, T.R.; Morhard, D.; Becker, C.; Reiser, M.; Nikolaou, K. [Inst. fuer Klinische Radiologie, Campus Grosshadern, Klinikum der Univ. Muenchen (Germany)

    2008-10-15

    To evaluate the feasibility of dual-energy CT angiography (CTA) of the lung in patients with suspected pulmonary embolism (PE). 24 patients with suspected PE were examined with a single-acquisition, dual-energy CTA protocol (A-system: 140 kV/65 mAsref, B-system: 80 kV/190 mAsref) on a dual-source CT system. Lung perfusion was visualized by color-coding voxels containing iodine and air using dedicated dual-energy post-processing software. Perfusion defects were classified by two blinded radiologists as being consistent or non-consistent with PE. Subjective image quality of perfusion maps and CTA was rated using a 5-point scale (1: excellent, 5: poor). The reading of a third independent radiologist served as the standard of reference for the diagnosis of PE. In all patients with PE (n = 4), perfusion defects classified as being consistent with PE were identified in lung areas affected by PE. Both readers did not record perfusion defects classified as being consistent with PE in any of the patients without PE. Thus, on a per patient basis the sensitivity and specificity for the assessment of PE was 100% for both readers. On a per segment basis the sensitivity and specificity ranged between 60 - 66.7% and 99.5 - 99.8%. The interobserver agreement was good (k = 0.81). Perfusion defects rated as non-consistent with PE were most frequently caused by streak artifacts from dense contrast material in the great thoracic vessels. The median score of the image quality of both the perfusion maps and CTA was 2. In conclusion, dual-energy CTA of pulmonary embolism is feasible and allows the assessment of perfusion defects caused by pulmonary embolism. Further optimization of the injection protocol is required to reduce artifacts from dense contrast material. (orig.)

  1. Dual-source CT with multiplanar reconstruction and volume rendering three-dimensional reconstruction in the evaluation of rib fractures%双源CT结合多平面重建与容积再现三维重建技术评价肋骨骨折

    Institute of Scientific and Technical Information of China (English)

    钱斌; 邹新农; 姚选军; 陶广宇; 王凯; 陈宏伟

    2011-01-01

    背景:依靠胸部摄片诊断肋骨骨折常导致误诊和漏诊.目的:分析双源CT 结合三维重建技术在肋骨骨折中的应用价值.方法:使用双源CT 对65 例肋骨骨折患者进行薄层扫描,将数据发送至工作站行多平面重建、容积再现技术,得到肋骨骨折高清晰度的三维图像后,从不同角度观察骨折线走行、骨折移位及成角情况.结果与结论:双源CT 结合三维重建图像清晰显示65 例患者286 根骨折,其中52 例保守治疗,其余13 例行切开复位、内固定治疗.制定手术方案时均参考了三维重建图像,所显示的骨折部位、移位、成角等情况与术中所见一致.提示双源CT 能明确诊断肋骨骨折,多平面重建和容积再现技术互相补充对诊断肋骨骨折及指导治疗方案有明显的优势.%BACKGROUND: Diagnosis of rib fractures relying on the chest radiograph diagnosis often leads to misdiagnos is. OBJECTIVE: To investigate the application of dual-source CT with three-dimensional reconstruction in rib fractures. METHODS: Sixty-five patients with rib fractures were scanned with dual-source CT. The data were sent to the workstation line of multi-planar reconstruction using volume rendering technique, to obtain high-resolution three-dimersion al images of rib fractures, and to observe the fracture line courses, fracture displacement and angulation of the situation from different angles. RESULTS AND CONCLUSION: The combination of dual-source CT and three-dimensional reconstruction images clearly showed 286 fractures in 65 patients, including 52 cases of consenrvative treatment, and the remaining 13 cases of surgery. The surgery programs in all patients were developed with reference to three- dimensional reoonstruction images showing the fracture position, displacement, angulation. Etc., consistent with the intraoperative findings. Dual-source CT can confirm the diagnose of rib fractures, and multi-planar reconstruction and volume

  2. 双源CT冠状动脉造影在心律失常患者的临床应用%Clinical Application of Dual-source CT Coronary Angiography in Patients with Arrhythmia

    Institute of Scientific and Technical Information of China (English)

    胡春峰; 徐凯; 袁莹莹; 汪秀玲; 李绍东; 程广军; 谢丽响

    2012-01-01

    Purpose: To study the clinical application value of dual-source CT coronary angiography (DSCT-CA) in patients with arrhythmia. Methods: Seventy-three patients with arrhythmia (29 patients with ventricular extrasystoles, 25 with atrial extrasystoles, 19 with atrial fibrillation) underwent DSCT-CA in this study. Retrospective gating technique and ECG editing technique were used. Coronary segment image quality was evaluated by four-grade method. Average heart rate and heart rate variability between ECG-editing group and no ECG- editing group and the image quality of pre-editing and post-editing in ECG-editing group were compared respectively. Results: In 73 patients, ECG-editing was not needed in 14 patients, and ECG-editing was needed in 59 patients. The average heart rate and heart rate variability between ECG-editing group and no ECG-editing group was with significant difference (P< 0.05 ). The image quality in every segment of ECG-editing group between pre-editing and post-editing was also with significant difference ( P < 0.05 ). After ECG-editing, 11 segments did not reach diagnosis requirements. Conclusion: DSCT-CA can be used in patients with arrhythmia. The image quality of coronary artery could be significantly improved with ECG-editing in patients with arrhythmia, but the key to improve the quality of image is to control heart rate and heart rate variability.%目的:探讨双源CT冠状动脉造影(DSCT-CA)在心律失常患者中的临床应用价值.方法:行DSCT-CA的心律失常患者共73例(室性期前收缩29例,房性期前收缩25例,心房纤颤19例),采用回顾性心电门控重建图像及心电编辑技术,对各段血管图像质量分级,比较无需编辑组与需编辑组的平均心率及心率波动、需编辑组各段冠状动脉编辑前后的图像质量.结果:73例中14例为无需编辑组,59例为需编辑组.无需编辑组的平均心率、心率波动均明显低于需编辑组(P<0.05).心电编辑后各段冠状动脉

  3. Value of Dual-source CT Angiography in the Diagnosis of Vertebral Artery Sulcus Ring%双源 CTA 在椎动脉沟环中的诊断价值

    Institute of Scientific and Technical Information of China (English)

    闫如意; 张朝利; 刘军华; 费军

    2014-01-01

    [Objective] To explore the value of dual-source CT angiography (DSCTA ) in the diagnosis of vertebral artery sulcus ring .[Methods]Clinical data of 62 patients with vertebral artery sulcus ring diagnosed by DSCTA were col-lected .The types of whole-ring-type vertebral artery sulcus ring were analyzed .The diameter of vertebral artery was measured .[Results] The types of 62 patients with vertebral artery included Ⅳ type in 38 patients(61 .3% ) in which 25 patients were bilateral whole-ring type and 13 patients were unilateral whole-ring type(8 patients with right side and 4 pa-tients with left side) ,Ⅲ type in 6 patients (9 .7% ) which were bone breaking in curve bone bridge arch with both beak-like sides ,typeⅠandⅡ in 18 patients(29 .0% ) in which 3 patients were type I anterior semi-ring and 15 patients were typeⅡ posterior semi-ring .The upper and lower diameters of whole-ring type vertebral artery sulcus ring were 3 .1~8 .2 (4 .8 ± 0 .3)mm and anteroposterior diameters were 4 .2~9 .1(7 .10 .3)mm .The diameter of vertebral artery in atlas ver-tebral artery sulcus ring was 1 .8~5 .9(3 .7 ± 0 .8)mm .Local stenosis of vertebral artery was found in 15 patients ,and the stenosis rate was 10% ~30% .[Conclusion]DSCTA can accurately display the shape of atlas vertebral artery sulcus ring and stenosis caused by vertebral artery entrapment .%【目的】探讨双源CT血管成像(CTA)在椎动脉沟环中的诊断价值。【方法】收集头颈部双源CTA检查中发现椎动脉沟环的患者62例的临床资料,分析椎动脉沟环分型并测量椎动脉直径。【结果】62例椎动脉沟环的分型:Ⅳ型38例,占61.3%,其中25例为双侧全环型,13例为单侧全环型(右侧8例、左侧4例);Ⅲ型6例,占9.7%,为弧形骨桥弓顶部骨质中断,两端呈鸟嘴状;Ⅰ型及Ⅱ型18例,占29.0%,其中Ⅰ型(前半环)3例、Ⅱ型(后半环)15例。测量全环型椎动脉沟环上下径3.1

  4. Feasibility and accuracy of tissue characterization with dual source computed tomography

    NARCIS (Netherlands)

    Van Abbema, Joanne K.; Van der Schaaf, Arjen; Kristanto, Wisnu; Groen, Jaap M.; Greuter, Marcel J. W.

    2012-01-01

    PURPOSE: To evaluate the feasibility and accuracy of a model for tissue characterization with dual source computed tomography (DSCT). METHODS AND MATERIALS: A model for tissue characterization in CT was used with a parameterization of linear attenuation coefficients. Sixteen chemical substances with

  5. 双源CT灌注成像在评估周围型肺癌血管生成中的临床价值%The Clinical Value of Dual-source CT Perfusion Imaging in the Evaluation of Generation of Peripheral Lung Cancer Angiogenesis

    Institute of Scientific and Technical Information of China (English)

    钟锦双; 陈国庆

    2016-01-01

    Objective To study the dual-source CT perfusion imaging in clinical application and value of peripheral lung cancer angiogenesis. MethodsFrom March 2014 to May 2016, the hospital make a diagnosis and give treatment line dual-source CT perfusion imaging in patients with 83 cases, of which 57 cases of lung cancer. Model adopts Siemens dual-source CT scans of patients with chest CT scan, determine the lesion, injection of contrast medium for continuous dynamic scanning, will get passed to analysis software for data processing.Results The patient with lung cancer CT perfusion parameters such as: BF, BV, TTP, signiifcantly higher than that of lung benign disease, the difference was statistically significant (P<0.05); Lung cancer patients with CT perfusion parameters values determined by MTT, signiifcantly lower than lung benign disease, the difference was statistically signiifcant (P<0.05); Organization level of EGFR and MVD in patients with lung cancer, is signiifcantly higher than tissue adjacent to carcinoma, the difference was statistically significant (P<0.05).Conclusion Dual-source CT perfusion imaging in patients with peripheral lung cancer tumor angiogenesis evaluation effect is ideal, is worthy of popularization and application.%目的:研究双源CT灌注成像在周围型肺癌血管生成中的临床应用及价值。方法选取2014年3月~2016年5月我院诊治的行双源CT灌注成像患者83例,其中肺癌57例。采用西门子双源CT扫描机型对患者行胸部CT平扫,确定病灶部位,注入对比剂进行连续动态扫描,将获得的数据传送到分析软件中进行处理。结果肺癌患者CT灌注参数值如:BF、BV、TTP,高于肺部良性疾病,差异具有统计学意义(P<0.05);肺癌患者CT灌注参数值MTT,显著低于肺部良性疾病,差异具有统计学意义(P<0.05);肺癌组织患者EGFR及MVD水平,高于癌旁组织,差异具有统计学意义(P<0.05

  6. Predictive value of low tube voltage and dual-energy CT for successful shock wave lithotripsy: an in vitro study.

    Science.gov (United States)

    Largo, Remo; Stolzmann, Paul; Fankhauser, Christian D; Poyet, Cédric; Wolfsgruber, Pirmin; Sulser, Tullio; Alkadhi, Hatem; Winklhofer, Sebastian

    2016-06-01

    This study investigates the capabilities of low tube voltage computed tomography (CT) and dual-energy CT (DECT) for predicting successful shock wave lithotripsy (SWL) of urinary stones in vitro. A total of 33 urinary calculi (six different chemical compositions; mean size 6 ± 3 mm) were scanned using a dual-source CT machine with single- (120 kVp) and dual-energy settings (80/150, 100/150 Sn kVp) resulting in six different datasets. The attenuation (Hounsfield Units) of calculi was measured on single-energy CT images and the dual-energy indices (DEIs) were calculated from DECT acquisitions. Calculi underwent SWL and the number of shock waves for successful disintegration was recorded. The prediction of required shock waves regarding stone attenuation/DEI was calculated using regression analysis (adjusted for stone size and composition) and the correlation between CT attenuation/DEI and the number of shock waves was assessed for all datasets. The median number of shock waves for successful stone disintegration was 72 (interquartile range 30-361). CT attenuation/DEI of stones was a significant, independent predictor (P waves with the best prediction at 80 kVp (β estimate 0.576) (P waves ranged between ρ = 0.31 and 0.68 showing the best correlation at 80 kVp (P < 0.001). The attenuation of urinary stones at low tube voltage CT is the best predictor for successful stone disintegration, being independent of stone composition and size. DECT shows no added value for predicting the success of SWL.

  7. 双源CT非心率控制自适应前瞻性心电门控序列扫描冠状动脉成像%CT coronary angiography without heart rate control with adaptive cardio sequence prospective ECG-gated using the second generation dual-source CT

    Institute of Scientific and Technical Information of China (English)

    王小琴; 钱农; 潘昌杰; 薛跃君; 王涛; 靳激扬

    2012-01-01

    Objective To explore the feasibility of improving image quality of low dose scanning using adaptive cardio sequence prospective ECG-gated without heart rate control by the second generation dual-source CT coronary angiography (CTCA). Methods Ninety-four consecutive patients were collected prospectively and underwent prospective ECG-gated a-daptive cardio sequence dual-source CTCA without heart rate control. Two experienced radiologists double-blindly assessed image quality of 15 segments of coronary arteries with five-score scale. Images with no less than 3 scores were usable for diagnosis. Correlation between image quality and heart rate, as well as with heart rate variability were analyzed. The intra-observer agreement for image quality was assessed. CT dose index of volume (CTDIvol) and effective dose (ED) were measured. Results The mean heart rate during scanning was (87. 24 13. 76) beats percent minute in all 94 patients. Totally 1410 segments of coronary arteries were included, and images useful for diagnosis (≥3 scores) were obtained in 1334 segments (94. 61%) of the coronary artery segments, while 76 segments (5. 39%) had non-assessable image quality. The mean image quality score for the whole coronary tree was 4. 25 0. 93. No correlation was observed between the mean heart rate (r= 0. 17, P = 0. 11) or heart rate variability (r=0. 10, P = 0. 32) and image quality. The Kappa value between two radiologists was 0.90 on image quality (P<0.001). CTDIvol and ED was (11.84+ 1.76)mGy and (2. 19 + 0. 45)mSv, respectively. Conclusion Using prospective ECG-gated adaptive cardio sequence, assessable image quality of coronary artery can be acquired with dual-source CT without heart rate control, and radiation dose can be obviously reduced.%目的 探讨双源CT非心率控制低剂量自适应前瞻性心电门控序列扫描冠状动脉成像的可行性.方法 前瞻性收集94例患者进行双源CT非心率控制自适应前瞻性心电门控序列扫

  8. Dual energy CT. A new perspective in the diagnosis of gout; Dual Energy CT. Eine neue Perspektive in der Gicht-Diagnostik

    Energy Technology Data Exchange (ETDEWEB)

    Artmann, Andreas; Ratzenboeck, M.; Noszian, I. [Radiologie II, Klinikum Wels Grieskirchen (Austria); Inst. fuer Digitale Schnittbildtechnik, Wels (Austria); Trieb, K. [Orthopaedie, Klinikum Wels Grieskirchen (Austria)

    2010-03-15

    Purpose: To describe the first experience with dual energy CT (DECT) for the diagnosis of gout and to evaluate its potential for the clinical routine. Materials and Methods: DECT examinations acquired with a dual source CT of 71 regions from 41 patients were evaluated with respect to image quality, amount of urate deposits and their location. The amount of urate deposits was described using a 4-stage scale: none (1), minimal punctual (up to 2 mm) (2), at least moderate (bigger than 2 mm) (3), soft tissue or osseus tophi (4). The DECT results were compared with the findings of the diagnostic tools currently in use. Results: The DECTs of peripheral regions showed excellent image quality, while the image quality was poor in the regions of the trunk. Patients (n) and regions (r) with a score of 3 (n = 23, r = 44), 4 (n=5, r=8) and 1 (n=2, r=2) showed a highly significant correlation (p<0.01) with the currently available diagnostic tools. In patients or regions with a score of 2 (n = 7, r = 11), the urate deposits were asymptomatic, the serum urate levels were partly elevated (43%) and partly normal (57%). The symptoms were ultimately able to be associated with a differential diagnosis. The urate deposits were found in tendons (57), articular synovia (25), cartilage (17), soft tissue tophi (8), osseus tophi (5), cruciate ligaments (7) and menisci (7). Conclusion: DECT allows specific and quantitative visualization of urate deposits in peripheral regions. Taking into account the amount of urate deposits shown in DECT, the diagnosis of gout can be stated reliably. Based on our experience and results, DECT greatly benefits the routine diagnosis of gout in peripheral regions. (orig.)

  9. Systematic review of the accuracy of dual-source cardiacct for detection of arterial stenosis in difficult to image patient groups

    NARCIS (Netherlands)

    M. Westwood (Marie); H. Raatz (Heike); K. Misso (Kate); L.T. Burgers (Laura); W.K. Redekop (Ken); S.K. Lhachimi (Stefan); N. Armstrong (Nigel); J. Kleijnen (Jos)

    2013-01-01

    textabstractPurpose: To assess the diagnostic performance of dual-source cardiac (DSC) computed tomography (CT) newer-generation CT instruments for identifying anatomically significant coronary artery disease (CAD) in patients who are difficult to image by using 64-section CT. Materials and Methods:

  10. 双源CT全脑灌注对短暂性脑缺血发作脑血流动力学变化的评价%The evaluation of cerebral hemodynamic changes of transient ischemic attack in dual source CT perfusion

    Institute of Scientific and Technical Information of China (English)

    卞力勇

    2015-01-01

    Objective To explore cerebral hemodynamic changes of transient ischemic attack(TIA)in dual source CT perfusion(CTP). Method Twenty patients with suspected TIA underwent plain CT and CTP within 24h of the onset of symptoms. The results of the abnormal regions of the cerebral blood flow and the contralatcral normal region were comparatively analyzed. Result Lacunar infarction were found in 15 out of 20 patients who were all with abnormal perfusion area. The imaging results demonstrated that significantly larger time to peak(TTP) delay in 20 patients with abnormal perfusion area was found compared with that in contralateral normal region(P 0.05),and no significant change of cerebral blood flow(CBF) was found.Conclusion CTP with dual source CT can accurately display cerebral hemodynamic changes of transient ischemic attack(TIA) and provides objective evidence for early diagnosis and treatment.%目的:探讨双源CT全脑灌注对短暂性脑缺血发作(transient ischemic attack, TIA)血流动力学改变的临床价值。方法临床拟诊TIA患者20例,均在症状出现24小时内行头颅CT平扫及CT Perfusion检查,将脑血流异常区与健侧对应区的情况做对比分析。结果20例患者中,15例患者出现腔梗改变。20例患者均出现灌注异常区,患侧达峰时间(time to peak,TTP)时间较健侧明显延长(P0.05),所有患者脑血流量(cerebral blood flow,CBF)无明显改变。结论双源CT全脑灌注能较好地反映TIA脑血流动力学变化,为早期诊断、治疗提供客观依据。

  11. Making the invisible visible: improving conspicuity of noncalcified gallstones using dual-energy CT.

    Science.gov (United States)

    Uyeda, Jennifer W; Richardson, Ian J; Sodickson, Aaron D

    2017-06-28

    To determine whether virtual monochromatic imaging (VMI) increases detectability of noncalcified gallstones on dual-energy CT (DECT) compared with conventional CT imaging. This retrospective IRB-approved, HIPAA-compliant study included consecutive patients who underwent DECT of the abdomen in the Emergency Department during a 30-month period (July 1, 2013-December 31, 2015), with a comparison US or MR within 1-year. 51 patients (36F, 15M; mean age 52 years) fulfilled the inclusion criteria. All DECT were acquired on a dual-source 128 × 2 slice scanner using either 80/Sn140 or 100/Sn140 kVp pairs. Source images at high and low kVp were used for DE post-processing with VMI. Within 3 mm reconstructed images, regions of interest of 0.5 cm(2) were placed on noncalcified gallstones and bile to record hounsfield units (HU) at VMI energy levels ranging between 40 and 190 keV. Noncalcified gallstones uniformly demonstrated lowest HU at 40 keV and increase at higher keV; the HU of bile varied at higher keV. Few of the noncalcified stones are visible at 70 keV (simulating a conventional 120 kVp scan), with measured contrast (bile-stone HU difference) 20 HU in 2%. Contrast was maximal at 40 keV, where 100% demonstrated >20 HU difference from surrounding bile, 75% >44 HU difference, and 50% >60 HU difference. A paired t test demonstrated a significant difference (p < 0.0001) between this stone-bile contrast at 40 vs. 70 keV and 70 vs. 190 keV. Low keV virtual monochromatic imaging increased conspicuity of noncalcified gallstones, improving their detectability.

  12. Tin-filter enhanced dual-energy-CT: image quality and accuracy of CT numbers in virtual noncontrast imaging.

    Science.gov (United States)

    Kaufmann, Sascha; Sauter, Alexander; Spira, Daniel; Gatidis, Sergios; Ketelsen, Dominik; Heuschmid, Martin; Claussen, Claus D; Thomas, Christoph

    2013-05-01

    To measure and compare the objective image quality of true noncontrast (TNC) images with virtual noncontrast (VNC) images acquired by tin-filter-enhanced, dual-source, dual-energy computed tomography (DECT) of upper abdomen. Sixty-three patients received unenhanced abdominal CT and enhanced abdominal DECT (100/140 kV with tin filter) in portal-venous phase. VNC images were calculated from the DECT datasets using commercially available software. The mean attenuation of relevant tissues and image quality were compared between the TNC and VNC images. Image quality was rated objectively by measuring image noise and the sharpness of object edges using custom-designed software. Measurements were compared using Student two-tailed t-test. Correlation coefficients for tissue attenuation measurements between TNC and VNC were calculated and the relative deviations were illustrated using Bland-Altman plots. Mean attenuation differences between TNC and VNC (HUTNC - HUVNC) image sets were as follows: right liver lobe -4.94 Hounsfield units (HU), left liver lobe -3.29 HU, vena cava -2.19 HU, spleen -7.46 HU, pancreas 1.29 HU, fat -11.14 HU, aorta 1.29 HU, bone marrow 36.83 HU (all P Mean image noise was significantly higher in TNC images (P images (P = .19). The Hounsfield units in VNC images closely resemble TNC images in the majority of the organs of the upper abdomen (kidneys, liver, pancreas). In spleen and fat, Hounsfield numbers in VNC images are tend to be higher than in TNC images. VNC images show a low image noise and satisfactory edge sharpness. Other criteria of image quality and the depiction of certain lesions need to be evaluated additionally. Copyright © 2013 AUR. Published by Elsevier Inc. All rights reserved.

  13. Evaluation of combined coronary CT angiography and dual-energy myocardial perfusion imaging for detection of acute myocardial infarction via second-generation dual-source CT:an experimental study in a porcine phantom model%第二代双源CT冠状动脉成像结合双能量心肌灌注评价猪急性心肌梗死的实验研究

    Institute of Scientific and Technical Information of China (English)

    孙凯; 李坤成; 韩瑞娟; 白栓成; 王君艳; 钱毅东; 刘智慧

    2015-01-01

    Objective To evaluate the diagnostic accuracy of dual-energy “one-step” combined CT coronary angiography ( CCTA ) and myocardial perfusion imaging ( MPI ) for the detection of acute myocardial infarction via second-generation dual-source CT compared with histopathological and conventional coronary angiography (CAG) findings in a porcine phantom. Methods Seven minipigs underwent transcatheter embolization of the coronary arteries by using gelatin sponge to produce acute myocardial infarction. CAG, dual-energy CCTA, and MPI were performed 20 min before, immediately after, and 24 h following the modeling procedure, respectively. A color-coded iodine map was used to evaluate the myocardial perfusion defects on the 17-segment model. In consensus, two radiologists interpreted all iodine map imaging results from MPI and CCTA. Considering CAG and pathological staining as gold standards, the sensibility and specificity of the CCTA and iodine maps from MPI were evaluated using dual-energy CT. Results Following coronary embolization, dual-energy CT iodine maps showed 45 infarcted segments and 40 non-infarcted segments. Per-segment analysis indicated the sensitivity, specificity, positive predictive value and negative predictive value as 93%, 95%, 95% and 93%, respectively. The corresponding values obtained by per-territory analysis were 100%, 86%, 89%and 100%, with CAG and histopathological findings as reference standards. The effective radiation dose of each dual-energy scan was 3.07±0.85 mSv(2.21-4.49 mSv). Conclusions Dual-energy “one-step” combined CCTA and MPI iodine maps for the detection of acute myocardial infarction via second-generation dual-source CT showed enhanced diagnostic accuracy with CAG and histopathology as gold standards.%目的:通过建立猪急性心肌梗死模型,以组织病理学和冠状动脉造影(CAG)结果为金标准,评价第二代双源CT双能量“一站式”冠状动脉CT血管造影(CCTA)结合心

  14. The performance of abdominal visceral artery aneurysm angiography with dual-source CT%腹部内脏动脉瘤双源CT血管造影表现

    Institute of Scientific and Technical Information of China (English)

    岳学旺; 孔生; 孔淑红

    2015-01-01

    Objective To investigate the performance of abdominal visceral artery aneurysm in dual‐source CT angiogra‐phy (CTA) and to evaluate the clinical value of CTA in the diagnosis of abdominal visceral artery aneurysm .Methods Thirty patients of spontaneous abdominal visceral artery aneurysm were analyzed retrospectively and combined the original and post‐processing images (VR ,CPR ,MIP ,MPR) for diagnosis .Results 30 cases of patients with abdominal visceral artery aneurysm were successfully completed the CT angiography ,and the images were clear .CTA can clearly display the aneurysm ,including 3 polyarteritis nodosa patients who had multiple viscera aneurysm .Besides ,28 patients of solitary an‐eurysm included 12 cases of dplenic aneurysm ,3 cases of hepatic artery aneurysm ,8 cases of renal artery aneurysm (one of patients had aneurysm in bilateral respectively) ,1 case of celiac trunkaneurysm ,1 case of pseudoaneurysm of celiac trunk and 3 cases of superior mesenteric aneurysm .Conclusion Dual‐soure CT angiography and post‐processing technology have a good diagnostic valve for abdominal visceral artery aneurysm and relative disease and it provides the basis for clinical di‐agnosis and treatment .%目的:探讨腹部内脏动脉瘤双源CT血管造影(CTA)的表现。方法回顾性分析30例腹部内脏动脉瘤患者CT原始及后处理图像,主要应用容积显示(VR)、最大密度投影(MIP)、曲面重组(CPR)、多平面重组(MPR)等后处理技术,进行图像重建观察动脉瘤情况,并结合横断面图像对疾病进行诊断。结果30例腹部内脏动脉血管造影成功,图像清晰。CTA能清晰显示腹部内脏动脉瘤,包括3例结节性多动脉炎患者,均可见多发内脏动脉瘤,此外单发动脉瘤中包括:脾动脉瘤12例、肝动脉瘤3例、肾动脉瘤8例(1例患者双肾均可见一单发动脉瘤)、腹腔干动脉瘤1例、腹腔干假性动脉瘤1例、肠系

  15. Feasibility and Diagnostic Accuracy for Assessment of Coronary Artery Stenosis of Prospectively Electrocardiogram-gated High-pitch Spiral Acquisition Mode Dual-source CT Coronary Angiography in Patients with Relatively Higher Heart Rates:in Comparison wit

    Institute of Scientific and Technical Information of China (English)

    Kai Sun; Rui-juan Han; Li-fang Cui; Rui-ping Zhao; Li-jun Ma; Li-jun Wang; Li-gang Li; Chang-yong Li

    2012-01-01

    Objective To prospectively investigate the diagnostic accuracy for coronary artery stenosis of prospectively electrocardiogram-triggered spiral acquisition mode (high pitch mode) dual-source computed tomography coronary angiography (CTCA) in patients with relatively higher heart rates (HR) compared with catheter coronary angiography (CCA).Methods Forty-seven consecutive patients with relatively higher HR (>65 and < 100 bpm) (20 male,27 female; age 55 ± 10 years) who both underwent dual-source CTCA and CCA were prospectively included in this study.All patients were performed CTCA using high pitch mode setting at 20%-30% of the R-R interval for the image acquisition.All coronary segments were evaluated by two blinded and independent observers with regard to image quality on a three-point scale (1:excellent to 3:non-diagnostic) and for the presence of significant coronary stenoses (defined as diameter narrowing exceeding 50%).Considered CCA as the standard of reference,the sensitivity,specificity,positive predictive value and negative predictive value were calculated.Radiation dose values were calculated using the dose-length product.Results Image quality was rated as being score 1 in 92.4% of segments,score 2 in 6.1% of segments and score 3 in 1.5% of segments.The average image quality score per segment was 1.064±0.306.The HR variability of patients with image score 1,2 and 3 were 2.29± 1.06 bpm,5.17± 1.37 bpm,8.88± 1.53 bpm,respectively.The average HR variability of patients with different image scores were significantly different (F=170.402,P=0.001).The sensitivity,specificity,positive and negative predictive values were 92.6%,97.0%,87.6%,98.3%,respe ctively,per segment and 90.0%,95.2%,85.3%,96.9%,respectively,per vessel and 100%,63.6%,90.0%,100%,respectively,per patient.The effective radiation dose was on average 0.86±0.16 mSv.Conclusion In patients with HR more than 65 bpm and below 100 bpm without cardiac arrhythmia

  16. Accuracy, image quality and radiation dose comparison of high-pitch spiral and sequential acquisition on 128-slice dual-source CT angiography in children with congenital heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Nie, Pei; Wang, Ximing; Cheng, Zhaoping; Ji, Xiaopeng; Duan, Yanhua [Shandong University, Shandong Provincial Key Laboratory of Diagnosis and Treatment of Cardio-cerebral Vascular Diseases, Shandong Medical Imaging Research Institute, Jinan, Shandong (China); Chen, Jiuhong [CT Research Collaboration, Siemens Ltd. China, Beijing (China)

    2012-10-15

    To compare accuracy, image quality and radiation dose between high-pitch spiral and sequential modes on 128-slice dual-source computed tomographic (DSCT) angiography in children with congenital heart disease (CHD). Forty patients suspected with CHD underwent 128-slice DSCT angiography with high-pitch mode and sequential mode respectively. All the anomalies were confirmed by the surgical and/or the conventional cardiac angiography (CCA) findings. The diagnostic accuracy, the subjective and objective image quality and effective radiation doses were compared. There was no significant difference in diagnostic accuracy ({chi}{sup 2} = 0.963, P > 0.05), the objective parameters for image quality (P > 0.05) and the image quality of great vessels (u = 167.500, P > 0.05) between the two groups. The image quality of intracardiac structures and coronary arteries was significantly better in the sequential mode group than that in the high-pitch group (u = 112.500 and 100.000, P < 0.05). The mean effective dose in high-pitch group (0.17 {+-} 0.05 mSv) was significantly lower (t = 5.287, P < 0.05) than that in the sequential mode group (0.29 {+-} 0.09 mSv). Both the high-pitch and the sequential modes for 128-slice DSCT angiography provide high accuracy for the assessment of CHD in children, while the high-pitch mode, even with some image quality decrease, further significantly lowers the radiation dose. (orig.)

  17. Evaluation of hyperdense renal lesions incidentally detected on single-phase post-contrast CT using dual-energy CT

    Science.gov (United States)

    Park, Jung Jae; Park, Byung Kwan

    2016-01-01

    Objective: To investigate the utility of dual-energy CT (DECT) for differentiating between solid and benign cystic lesions presenting as hyperdense renal lesions incidentally detected on single-phase post-contrast CT. Methods: 90 hyperdense renal lesions incidentally detected on single-phase post-contrast CT were evaluated with follow-up DECT. DECT protocols included true non-contrast (TNC), DE corticomedullary and DE late nephrographic phase imaging. The CT numbers of hyperdense renal lesions were calculated on linearly blended and iodine overlay (IO) images, and the results were compared. Results: In total, 47 benign cystic and 43 solid renal lesions were analyzed. For differentiating between solid and benign cystic lesions on the two phases, the specificity and accuracy of all lesions and lesions  0.05). For all types of lesions ≥1.5 cm, the CT numbers between linearly blended and IO images and between TNC and virtual non-contrast images were not statistically different (p > 0.05). Conclusion: DECT may be useful for differentiating between solid and benign cystic lesions presenting as hyperdense renal lesions incidentally detected on single-phase post-contrast CT, particularly with the size ≥1.5 cm. Advances in knowledge: DECT may be used to characterize hyperdense renal lesions ≥1.5 cm incidentally detected on single-phase post-contrast CT, without the use of TNC images. PMID:27043480

  18. Dual-energy compared to single-energy CT in pediatric imaging: a phantom study for DECT clinical guidance

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Xiaowei; Servaes, Sabah; Darge, Kassa [The Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States); University of Pennsylvania, The Perelman School of Medicine, Philadelphia, PA (United States); McCullough, William P. [University of Virginia Health System, Department of Radiology and Medical Imaging, Charlottesville, VA (United States); Mecca, Patricia [The Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States)

    2016-11-15

    Dual-energy CT technology is available on scanners from several vendors and offers significant advantages over classic single-energy CT technology in multiple clinical applications. Many studies have detailed dual-energy CT applications in adults and several have evaluated the relative radiation dose performance of dual-energy CT in adult imaging. However, little has been published on dual-energy CT imaging in the pediatric population, and the relative dose performance of dual-energy CT imaging in the pediatric population is not well described. When evaluating dual-energy CT technology for implementation into a routine clinical pediatric imaging practice, the radiation dose implications must be considered, and when comparing relative CT dose performance, image quality must also be evaluated. Therefore the purpose of this study is to develop dual-energy CT scan protocols based on our optimized single-energy scan protocols and compare the dose. We scanned the head, chest and abdomen regions of pediatric-size anthropomorphic phantoms with contrast inserts, using our optimized single-energy clinical imaging protocols on a Siemens Flash {sup registered} CT scanner. We then scanned the phantoms in dual-energy mode using matching image-quality reference settings. The effective CT dose index volume (CTDI{sub vol}) of the scans was used as a surrogate for relative dose in comparing the single- and dual-energy scans. Additionally, we evaluated image quality using visual assessment and contrast-to-noise ratio. Dual-energy CT scans of the head and abdomen were dose-neutral for all three phantoms. Dual-energy CT scans of the chest showed a relative dose increase over the single-energy scan for 1- and 5-year-old child-based age-equivalent phantoms, ranging 11-20%. Quantitative analysis of image quality showed no statistically significant difference in image quality between the single-energy and dual-energy scans. There was no clinically significant difference in image quality by

  19. Deep multi-spectral ensemble learning for electronic cleansing in dual-energy CT colonography

    Science.gov (United States)

    Tachibana, Rie; Näppi, Janne J.; Hironaka, Toru; Kim, Se Hyung; Yoshida, Hiroyuki

    2017-03-01

    We developed a novel electronic cleansing (EC) method for dual-energy CT colonography (DE-CTC) based on an ensemble deep convolution neural network (DCNN) and multi-spectral multi-slice image patches. In the method, an ensemble DCNN is used to classify each voxel of a DE-CTC image volume into five classes: luminal air, soft tissue, tagged fecal materials, and partial-volume boundaries between air and tagging and those between soft tissue and tagging. Each DCNN acts as a voxel classifier, where an input image patch centered at the voxel is generated as input to the DCNNs. An image patch has three channels that are mapped from a region-of-interest containing the image plane of the voxel and the two adjacent image planes. Six different types of spectral input image datasets were derived using two dual-energy CT images, two virtual monochromatic images, and two material images. An ensemble DCNN was constructed by use of a meta-classifier that combines the output of multiple DCNNs, each of which was trained with a different type of multi-spectral image patches. The electronically cleansed CTC images were calculated by removal of regions classified as other than soft tissue, followed by a colon surface reconstruction. For pilot evaluation, 359 volumes of interest (VOIs) representing sources of subtraction artifacts observed in current EC schemes were sampled from 30 clinical CTC cases. Preliminary results showed that the ensemble DCNN can yield high accuracy in labeling of the VOIs, indicating that deep learning of multi-spectral EC with multi-slice imaging could accurately remove residual fecal materials from CTC images without generating major EC artifacts.

  20. Accuracy of iodine removal using dual-energy CT with or without a tin filter: an experimental phantom study.

    Science.gov (United States)

    Kawai, Tatsuya; Takeuchi, Mitsuru; Hara, Masaki; Ohashi, Kazuya; Suzuki, Hirochika; Yamada, Kiyotaka; Sugimura, Yuya; Shibamoto, Yuta

    2013-10-01

    The effects of a tin filter on virtual non-enhanced (VNE) images created by dual-energy CT have not been well evaluated. To compare the accuracy of VNE images between those with and without a tin filter. Two different types of columnar phantoms made of agarose gel were evaluated. Phantom A contained various concentrations of iodine (4.5-1590 HU at 120 kVp). Phantom B consisted of a central component (0, 10, 25, and 40 mgI/cm(3)) and a surrounding component (0, 50, 100, and 200 mgI/cm(3)) with variable iodine concentration. They were scanned by dual-source CT in conventional single-energy mode and dual-energy mode with and without a tin filter. CT values on each gel at the corresponding points were measured and the accuracy of iodine removal was evaluated. On VNE images, the CT number of the gel of Phantom A fell within the range between -15 and +15 HU under 626 and 881 HU at single-energy 120 kVp with and without a tin filter, respectively. With attenuation over these thresholds, iodine concentration of gels was underestimated with the tin filter but overestimated without it. For Phantom B, the mean CT numbers on VNE images in the central gel component surrounded by the gel with iodine concentrations of 0, 50, 100, and 200 mgI/cm(3) were in the range of -19-+6 HU and 21-100 HU with and without the tin filter, respectively. Both with and without a tin filter, iodine removal was accurate under a threshold of iodine concentration. Although a surrounding structure with higher attenuation decreased the accuracy, a tin filter improved the margin of error.

  1. Characterisation of urinary stones in the presence of iodinated contrast medium using dual-energy CT: a phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jia; Qu, Mingliang; Duan, Xinhui; Takahashi, Naoki; Kawashima, Akira; Leng, Shuai; McCollough, Cynthia H. [Mayo Clinic, Department of Radiology, Rochester, MN (United States)

    2012-12-15

    To develop a dual-energy CT (DECT) method for differentiating uric acid (UA) from non-UA stones in the presence of iodinated contrast medium. Thirty UA and 45 non-UA stones were selected after infra-red spectroscopic analysis and independently placed in a 1.5-ml vial, which was filled first with saline and then with increasing concentrations of iodine. For each condition, tubes were put in a 35-cm water phantom and examined using a dual-source CT system at 100 and 140 kV. Virtual unenhanced images created from CT data sets of the stones in iodine-containing solutions provided position and volume information. This map was used to calculate a CT number ratio to differentiate stone type. A region-growing method was developed to improve the ability to differentiate between UA and non-UA stones with iodinated contrast medium. The sensitivity for detecting UA stones was 100 % for unenhanced images but fell to 18 % with 20 mgI/ml iodine solution and 0 % for higher concentrations. With region growing, the sensitivity for detecting UA stones was increased to 100 %, 82 %, 57 %, 50 % and 21 % for iodine solutions of 20, 40, 60, 80 and 100 mgI/ml. The region-growing method improves differentiation of UA from non-UA stones on contrast-enhanced DECT urograms. (orig.)

  2. Experimental verification of ion stopping power prediction from dual energy CT data in tissue surrogates.

    Science.gov (United States)

    Farace, Paolo

    2014-11-21

    A two-steps procedure is presented to convert dual-energy CT data to stopping power ratio (SPR), relative to water. In the first step the relative electron density (RED) is calculated from dual-energy CT-numbers by means of a bi-linear relationship: RED=a HUscH+b HUscL+c, where HUscH and HUscL are scaled units (HUsc=HU+1000) acquired at high and low energy respectively, and the three parameters a, b and c has to be determined for each CT scanner. In the second step the RED values were converted into SPR by means of published poly-line functions, which are invariant as they do not depend on a specific CT scanner. The comparison with other methods provides encouraging results, with residual SPR error on human tissue within 1%. The distinctive features of the proposed method are its simplicity and the generality of the conversion functions.

  3. Benefits of texture analysis of dual energy CT for Computer-Aided pulmonary embolism detection.

    Science.gov (United States)

    Foncubierta-Rodríguez, Antonio; Jiménez del Toro, Óscar Alfonso; Platon, Alexandra; Poletti, Pierre-Alexandre; Müller, Henning; Depeursinge, Adrien

    2013-01-01

    Pulmonary embolism is an avoidable cause of death if treated immediately but delays in diagnosis and treatment lead to an increased risk. Computer-assisted image analysis of both unenhanced and contrast-enhanced computed tomography (CT) have proven useful for diagnosis of pulmonary embolism. Dual energy CT provides additional information over the standard single energy scan by generating four-dimensional (4D) data, in our case with 11 energy levels in 3D. In this paper a 4D texture analysis method capable of detecting pulmonary embolism in dual energy CT is presented. The method uses wavelet-based visual words together with an automatic geodesic-based region of interest detection algorithm to characterize the texture properties of each lung lobe. Results show an increase in performance with respect to the single energy CT analysis, as well as an accuracy gain compared to preliminary work on a small dataset.

  4. Differentiation of kidney stones using dual-energy CT with and without a tin filter.

    Science.gov (United States)

    Fung, George S K; Kawamoto, Satomi; Matlaga, Brian R; Taguchi, Katsuyuki; Zhou, Xiaodong; Fishman, Elliot K; Tsui, Benjamin M W

    2012-06-01

    The aim of this in vitro study was to examine the capability of three protocols of dual-energy CT imaging in distinguishing calcium oxalate, calcium phosphate, and uric acid kidney stones. A total of 48 calcium oxalate, calcium phosphate, and uric acid human kidney stone samples were placed in individual containers inside a cylindric water phantom and imaged with a dual-energy CT scanner using the following three scanning protocols of different combinations of tube voltage, with and without a tin filter: 80 and 140 kVp without a tin filter, 100 and 140 kVp with a tin filter, and 80 and 140 kVp with a tin filter. The mean attenuation value (in Hounsfield units) of each stone was recorded in both low- and high-energy CT images in each protocol. The dual-energy ratio of the mean attenuation values of each stone was computed for each protocol. For all three protocols, the uric acid stones were significantly different (p filter protocol (AUC, 0.996), the 100- and 140-kVp tin filter protocol (AUC, 0.918), and the 80- and 140-kVp protocol (AUC, 0.871). The tin filter added to the high-energy tube and the use of a wider dual-energy difference are important for improving the stone differentiation capability of dual-energy CT imaging.

  5. Detection of pulmonary fat embolism with dual-energy CT: an experimental study in rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Chun Xiang; Zhou, Chang Sheng; Zhao, Yan E.; Han, Zong Hong; Qi, Li; Zhang, Long Jiang; Lu, Guang Ming [Medical School of Nanjing University, Department of Medical Imaging, Jinling Hospital, Nanjing, Jiangsu (China); Schoepf, U.J. [Medical School of Nanjing University, Department of Medical Imaging, Jinling Hospital, Nanjing, Jiangsu (China); Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Mangold, Stefanie; Ball, B.D. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States)

    2017-04-15

    To evaluate the use of dual-energy CT imaging of the lung perfused blood volume (PBV) for the detection of pulmonary fat embolism (PFE). Dual-energy CT was performed in 24 rabbits before and 1 hour, 1 day, 4 days and 7 days after artificial induction of PFE via the right ear vein. CT pulmonary angiography (CTPA) and lung PBV images were evaluated by two radiologists, who recorded the presence, number, and location of PFE on a per-lobe basis. Sensitivity, specificity, and accuracy of CTPA and lung PBV for detecting PFE were calculated using histopathological evaluation as the reference standard. A total of 144 lung lobes in 24 rabbits were evaluated and 70 fat emboli were detected on histopathological analysis. The overall sensitivity, specificity and accuracy were 25.4 %, 98.6 %, and 62.5 % for CTPA, and 82.6 %, 76.0 %, and 79.2 % for lung PBV. Higher sensitivity (p < 0.001) and accuracy (p < 0.01), but lower specificity (p < 0.001), were found for lung PBV compared with CTPA. Dual-energy CT can detect PFE earlier than CTPA (all p < 0.01). Dual-energy CT provided higher sensitivity and accuracy in the detection of PFE as well as earlier detection compared with conventional CTPA in this animal model study. (orig.)

  6. Detection of pulmonary fat embolism with dual-energy CT: an experimental study in rabbits.

    Science.gov (United States)

    Tang, Chun Xiang; Zhou, Chang Sheng; Zhao, Yan E; Schoepf, U Joseph; Mangold, Stefanie; Ball, B Devon; Han, Zong Hong; Qi, Li; Zhang, Long Jiang; Lu, Guang Ming

    2017-04-01

    To evaluate the use of dual-energy CT imaging of the lung perfused blood volume (PBV) for the detection of pulmonary fat embolism (PFE). Dual-energy CT was performed in 24 rabbits before and 1 hour, 1 day, 4 days and 7 days after artificial induction of PFE via the right ear vein. CT pulmonary angiography (CTPA) and lung PBV images were evaluated by two radiologists, who recorded the presence, number, and location of PFE on a per-lobe basis. Sensitivity, specificity, and accuracy of CTPA and lung PBV for detecting PFE were calculated using histopathological evaluation as the reference standard. A total of 144 lung lobes in 24 rabbits were evaluated and 70 fat emboli were detected on histopathological analysis. The overall sensitivity, specificity and accuracy were 25.4 %, 98.6 %, and 62.5 % for CTPA, and 82.6 %, 76.0 %, and 79.2 % for lung PBV. Higher sensitivity (p PFE earlier than CTPA (all p PFE as well as earlier detection compared with conventional CTPA in this animal model study. • Fat embolism occurs commonly in patients with traumatic bone injury. • Dual-energy CT improves diagnostic performance for pulmonary fat embolism detection. • Dual-energy CT can detect pulmonary fat embolism earlier than CTPA.

  7. 双源CT大螺距前瞻心电触发血管成像评价全主动脉及冠状动脉%Electrocardiographically triggered CT angiography of the whole aorta and coronary arteries with high-pitch dual-source CT

    Institute of Scientific and Technical Information of China (English)

    张楠; 李宇; 吕元; 赵龙; 耿薇; 范占明

    2013-01-01

    Objective To investigate the feasibility of comprehensive assessment of the whole aorta and coronary arteries (CA) simultaneously with high-pitch 128-slice dual-source CT ECG-gated FLASH protocol.Methods A total of 48 consecutive patients with suspected aortic diseases underwent CTA examination of the whole aorta and CA using a ECG-gated FLASH CT protocol (pitch =3.2) without heart rate (HR) control.Aorta,aortic valves and CA were shown with different post-processing modalities.The image quality of the aorta,aortic valves and CA was evaluated and compared according to HR (low HR group ≤ 65 bpm,high HR group > 65 bpm).The scan time,effective dose and contrast medium volume were recorded.Inter-observer differences were calculated by Kappa test.Differences between groups were analyzed by Mann-Whitney test with count data and variance test with measurement data.Results All examinations were completed successfully.The image quality was acceptable in the aorta,aortic valve (100%,48/48) and CA (94.0%,551/586).Percentage of diagnostic quality images was slightly higher in low HR group (94.7%,232/245,93.5%,319/341,Z =-2.504,P < 0.05).Inter-reader reproducibility was 95.8% (46/48) in the aorta and aortic valve,96.6% (566/586) in CA,yielded good agreement (Kappa =0.81 and 0.89).The mean attenuation of aorta and CA were higher than 300 HU,especially in low HR group (357.0-446.0) HU.Except proximal segment of right CA,the CNR of whole aorta and coronary arteries were significantly higher in the low HR group (24.5-29.0) than that in the high HR group (20.0-23.1,P <0.05).SNR of the whole aorta was higher in the low HR group (13.7-17.9) than the high HR group (11.5-13.9,P < 0.05).The mean scan time was (1.56 ± 0.08) s,effective dose was (4.12 ± 1.23) mSv (2.77-6.77 mSv),and contrast medium volume was (72.8 ± 2.1) ml.Conclusions CT angiography of whole aorta and coronary arteries could be performed simultaueously within 2 seconds with CT ECG-gated FLASH

  8. Advanced material separation technique based on dual energy CT scanning

    Science.gov (United States)

    Zamyatin, Alexander A.; Natarajan, Anusha; Zou, Yu

    2009-02-01

    We propose a method for material separation using dual energy data. Our method is suitable to separation of three or more materials. In this work we describe our method and show results of numerical simulation and with real dual-energy data of a head phantom. The proposed method of constructing the material separation map consists of the following steps: Data-domain dual energy decomposition - Vector plot - Density plot - Clustering - Color assignment. Density plots are introduced to allow automatic cluster separation. We use special image processing methods, including Gaussian decomposition, to improve the accuracy of material separation. We also propose using the HSL color model for better visualization and to bring a new dimension in material separation display. We study applications of bone removal and virtual contrast removal. Evaluation shows improved accuracy compared to standard methods.

  9. The low attenuation area on dual-energy perfusion CT: Correlation with the pulmonary function tests and quantitative CT measurements

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Munemasa, E-mail: radokada@yamaguchi-u.ac.jp [Department of Radiology, Yamaguchi University Graduate School of Medicine (Japan); Kunihiro, Yoshie; Nakashima, Yoshiteru; Matsunaga, Naofumi [Department of Radiology, Yamaguchi University Graduate School of Medicine (Japan); Sano, Yuichi; Yuasa, Yuuki; Narazaki, Akiko; Kudomi, Shohei; Koike, Masahiro [Department of Radiology, Yamaguchi University Hospital (Japan); Kido, Shoji [Computer-aided Diagnosis and Biomedical Imaging Research Biomedical Engineering, Applied Medical Engineering Science Graduate School of Medicine, Yamaguchi University (Japan)

    2012-10-15

    Purpose: To retrospectively investigate the distribution of the low attenuation area (LAA) on dual energy perfusion CT (DEpCT) in comparison with the results of pulmonary function tests (PFTs) and quantitative CT measurements. Materials and methods: Twenty-eight patients (15 male and 13 female; mean age: 62.21 years) underwent DEpCT and PFTs within a 1-month interval. The ranges of the LAA on DEpCT were classified into six groups with attenuation values of 0–3, 0–5, 0–8, 0–10, 0–13 and 0–15 HU and the ratios of LAA in each group were compared with the percentage of forced expiratory volume in the 1st second (%FEV{sub 1.0}), FEV{sub 1.0}/forced vital capacity (FEV{sub 1.0}/FVC) and the relative area of the lung with attenuation coefficients lower than −950 HU (RA{sub −950}). Results: The LAAs on the DEpCT images were significantly correlated with the RA{sub −950}, %FEV{sub 1.0} and FEV{sub 1.0}/FVC, and the regression analysis showed that the best values of LAA on DEpCT were 0–10 HU with RA{sub −950} (r = 0.63), 0–8 HU with %FEV{sub 1.0} (r = −0.52) and 0–8 HU with FEV{sub 1.0}/FVC (r = −0.61) per patient. Conclusion: The iodine disturbance on DEpCT had a moderate correlation with the results of the PFTs and RA{sub −950}, but further examination would be needed for evaluation of iodine distribution.

  10. Dual-energy direct bone removal CT angiography for evaluation of intracranial aneurysm or stenosis: comparison with conventional digital subtraction angiography

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Yoshiyuki [National Cardiovascular Center, Department of Radiology, Osaka (Japan); St. Luke' s International Hospital, Department of Radiology, Tokyo (Japan); Uotani, Kensuke; Nakazawa, Tetsuro; Higashi, Masahiro; Yamada, Naoaki; Hori, Yoshiro; Kanzaki, Suzu; Fukuda, Tetsuya; Naito, Hiroaki [National Cardiovascular Center, Department of Radiology, Osaka (Japan); Itoh, Toshihide [Siemens Asahi Medical Technologies, Tokyo (Japan)

    2009-04-15

    Dual-energy CT can be applied for bone elimination in cerebral CT angiography (CTA). The aim of this study was to compare the results of dual-energy direct bone removal CTA (DE-BR-CTA) with those of digital subtraction angiography (DSA). Twelve patients with intracranial aneurysms and/or ICA stenosis underwent a dual-source CT in dual-energy mode. Post-processing software selectively removed bone structures using the two energy data sets. Three-dimensional images with and without bone removal were reviewed and compared to DSA. Dual-energy bone removal was successful in all patients. For 10 patients, bone removal was good and CTA maximum-intensity projection (MIP) images could be used for vessel evaluation. For two patients, bone removal was moderate with some bone remnants, but this did not inhibit the three-dimensional visualization. Three aneurysms adjacent to the skull base were only partially visible in conventional CTA but were fully visible in DE-BR-CTA. In five patients with ICA stenosis, DE-BR-CTA revealed the stenotic lesions on the MIP images. The correlation between DSA and DE-BR-CTA was good (R {sup 2}=0.822), but DE-BR-CTA led to an overestimation of stenosis. DE-BR-CTA was able to eliminate bone structure using only a single CT data acquisition and is useful to evaluate intracranial aneurysms and stenosis. (orig.)

  11. Pancreatic adenocarcinoma: dual-phase helical CT with surgical and histopathologic correlation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun A; Yoon, Kwon Ha; Park, Seong Hoon; Yun, Ki Jung; Won, Jong Jin [Wonkwang University School of Medicine, Iksan (Korea, Republic of)

    2003-03-01

    To determine the accuracy of dual-phase helical CT in assessing the resectability of pancreatic ductal adenocarcinoma, and to correlate the CT findings with the surgical and histopathologic findings. Thirty patients with pathologically proven cancer of the pancreas underwent arterial-and portal-phase helical CT scanning, and in the two of these, single-level dynamic CT was performed during celiac and superior mesenteric arteriography. In 17 patients who underwent surgery for potentially resectable cancer of the pancreatic head, tumor resectability was assessed. The CT findings were analyzed and correlated with these of surgery and histopathology. In 13 (76%) of the 17 patients who underwent surgery, tumors were resectable. Their average size was 2.76 cm (arterial phase), 2.30 cm (portal phase), and 2.48 cm (pathologically determined) and the overall accuracy of helical CT for assessing resectability was 87%. In all patients, the central portion of the tumors exhibited hypoattenuation at both phases; the peripheral portion showed hypoattenuation at the arterial phase and iso- (n=10) or hyperattenuation (n=3) at the portal phase. Single-level dynamic CT depicted a persistently hypoattenuating central portion and progressive and prolonged enhancement of the periphery. CT-histopathologic correlation showed that central hypoattenuation indicated the presence of tumor cells, necrosis (n=3) and mucin (n=4), while the peripheral iso- or hyperattenuated areas seen at the portal phase represented fibrosis and inflammatory infiltration. Histopathologic examination revealed tumoral infiltration of peripancreatic fat tissue (n=11) and microvascular invasion of major peripancreatic vessels (n=7). The dual-phase helical CT is useful in the determination of resectability in pancreas cancer and CT findings represent well the histopathologic features of pancreas cancer.

  12. Can single-phase dual-energy CT reliably identify adrenal adenomas?

    Energy Technology Data Exchange (ETDEWEB)

    Helck, A.; Hummel, N.; Meinel, F.G.; Johnson, T.; Nikolaou, K.; Graser, A. [University of Munich, Institute for Clinical Radiology, Munich (Germany)

    2014-07-15

    To evaluate whether single-phase dual-energy-CT-based attenuation measurements can reliably differentiate lipid-rich adrenal adenomas from malignant adrenal lesions. We retrospectively identified 51 patients with adrenal masses who had undergone contrast-enhanced dual-energy-CT (140/100 or 140/80 kVp). Virtual non-contrast and colour-coded iodine images were generated, allowing for measurement of pre- and post-contrast density on a single-phase acquisition. Adrenal adenoma was diagnosed if density on virtual non-contrast images was ≤10 HU. Clinical follow-up, true non-contrast CT, PET/CT, in- and opposed-phase MRI, and histopathology served as the standard of reference. Based on the standard of reference, 46/57 (80.7 %) adrenal masses were characterised as adenomas or other benign lesions; 9 malignant lesions were detected. Based on a cutoff value of 10 HU, virtual non-contrast images allowed for correct identification of adrenal adenomas in 33 of 46 (71 %), whereas 13/46 (28 %) adrenal adenomas were lipid poor with a density ≥10 HU. Based on the threshold of 10 HU on the virtual non-contrast images, the sensitivity, specificity, and accuracy for detection of benign adrenal lesions was 73 %, 100 %, and 81 % respectively. Virtual non-contrast images derived from dual-energy-CT allow for accurate characterisation of lipid-rich adrenal adenomas and can help to avoid additional follow-up imaging. (orig.)

  13. Cardiac electrical mechanical coupling and flash dual-source CT coronary angiography in patients with high heart rates%心脏电机械偶联与Flash双源CT冠状动脉成像在高心率患者中的应用

    Institute of Scientific and Technical Information of China (English)

    韩瑞娟; 孙凯; 李立刚; 陈九宏

    2011-01-01

    Objective To assess the image quality and effective radiation dose of prospectively e -lectrocardiogram-triggered high-pitch spiral acquisition (flash spiral mode)dual-source CT coronary angiogra-phy in patients with high heart rate(HR).Methods From 1321 consecutive patients,seventy patients with HR≥70 bpm (group A) and seventy patients with HR <70 bpm (group B) underwent CT angiography and were prospectively included in this study .The start phase for image acquisition of the most cranial slice was selected at 20%-30% of the R-R interval for group A and at 60% of the RR interval for group B.Assessed the image quality and effective radiation dose of two group .Results (1)There were no significant differ-ences in age,sex,BMI and scan time between the two groups.(2)Image qualities:The segments with non-di-agnostic image quality occurred (i.e.score 3) had no significant difference between group A and group B (2.1% vs.1.5%,P=0.48).Non-diagnostic image quality was most often found in the RCA and LCX in both groups.(3)The estimated radiation dose was on average (1.00 ±0.15) mSv(0.7-1.82 mSv) in group A and (1.01 ±0.16)mSv (0.65-1.82 mSv) in group B.Conclusions Patients with high heart rates can be performed CTCA with high-pitch spiral acquisition mode.20%-30% of the R-R interval window for data ac-quisition for high-pitch dual-source CTCA may probably obtain good image quality with low doses .The high-est HRs are 100 bpm with good image quality.HR variability is a great effect factor of image quality .The esti-mated radiation dose is about 1 mSv.

  14. Analyzing radiation absorption difference of dental substance by using Dual CT

    Science.gov (United States)

    Yu, H.; Lee, H. K.; Cho, J. H.; Yang, H. J.; Ju, Y. S.

    2015-07-01

    The purpose of this study was to evaluate the changes of noise and computer tomography (CT) number in each dental substance, by using the metal artefact reduction algorithm; we used dual CT for this study. For the study, we produced resin, titanium, gypsum, and wax that are widely used by dentists. In addition, we made nickel to increase the artefact. While making the study materials, we made sure that there is no difficulty when inserting the substances inside phantom. In order to study, we scanned before and after using the metal artefact reduction algorithm. We conducted an average analysis of CT number and noise, before and after using the metal artefact reduction algorithm. As a result, there was no difference in CT number and noise before and after using the metal artefact reduction algorithm. However, when it comes to the noise value in each substance, wax's noise value was the lowest whereas titanium's noise value was the highest, after applying the metal artefact reduction algorithm. In nickel, CT number and noise value from artefact area showed a decreased noise value when applying the metal artefact reduction algorithm. In conclusion, we assumed that we could increase the effectiveness of CT examination by applying dual energy's metal artefact reduction algorithm.

  15. Dual-energy CT can detect malignant lymph nodes in rectal cancer

    DEFF Research Database (Denmark)

    Al-Najami, I.; Lahaye, M. J.; Beets-Tan, Regina G H

    2017-01-01

    node assessment, and compared it to Magnetic Resonance Imaging (MRI). The objective of this prospective observational feasibility study was to determine the clinical value of the DECT for the detection of metastases in the pelvic lymph nodes of rectal cancer patients and compare the findings to MRI......Background There is a need for an accurate and operator independent method to assess the lymph node status to provide the most optimal personalized treatment for rectal cancer patients. This study evaluates whether Dual Energy Computed Tomography (DECT) could contribute to the preoperative lymph...... a pelvic DECT scan and a standard MRI. The Dual Energy CT quantitative parameters were analyzed: Water and Iodine concentration, Dual-Energy Ratio, Dual Energy Index, and Effective Z value, for the benign and malignant lymph node differentiation. Results DECT scanning showed statistical difference between...

  16. Dual energy CT for the assessment of lung perfusion-Correlation to scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Thieme, Sven F.; Becker, Christoph R. [Department of Clinical Radiology, Ludwig-Maximilians-University of Munich (Germany); Hacker, Marcus [Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich (Germany); Nikolaou, Konstantin; Reiser, Maximilian F. [Department of Clinical Radiology, Ludwig-Maximilians-University of Munich (Germany); Johnson, Thorsten R.C. [Department of Clinical Radiology, Ludwig-Maximilians-University of Munich (Germany)], E-mail: thorsten.johnson@med.uni-muenchen.de

    2008-12-15

    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.

  17. A comparative study for Triple-Rule-out with different tube voltage technique of Dual-Source CT in acute chest pain%双源 CT不同管电压技术诊断急性胸痛三联症效果比较

    Institute of Scientific and Technical Information of China (English)

    王皆欢; 陈东风; 王少春; 孙占国; 王林省; 张谷青

    2014-01-01

    目的:对比双源CT胸痛三联检查在两种不同电压下显示急性胸痛患者肺动脉、主动脉及冠状动脉的图像质量以及患者所受的辐射剂量,以评估低电压扫描在急性胸痛患者推广应用的可行性。方法利用双源C T胸痛三联扫描模式,结合回顾性心电门控技术对361例胸痛三联检查患者进行统计分析,比较主动脉、肺动脉及冠状动脉的图像质量及辐射的有效剂量。结果120kV组与100kV组在图像质量的主观评分对比中差异无统计学意义(P>0.05),在患者辐射剂量的对比中,120kV组的辐射剂量大于100kV组,差异有统计学意义(P<0.05)。结论双源CT胸痛三联检查两种不同管电压扫描对急性胸痛患者的肺动脉、主动脉及冠状动脉的成像质量无影响,并且应用100kV 管电压扫描可以降低患者所受的辐射剂量,可以作为急性胸痛患者的首选。%Objective To compare the value of triple-rule-out (TRO) dual-source computed tomography angiog-raphy in acute chest pain patients with diseases of pulmonary artery ,aortic and coronary artery and radiation dose in two different voltage as well as the feasibility of generalizing and applying in patients with acute chest pain . Methods 361 patients with chest pain were analyzed statistically underwent triple-rule-out (TRO) dual-source CT combined with retrospective ECG-gated technique ,and then compare with image quality of aorta ,pulmonary artery and coronary artery and effective radiation dose .Results Subjective score of image quality of the voltage 120kV and 100kV group had no statistical significance(P>0.05) .The difference was statistically significant(P<0.05)in comparison of radiation dose .The effective radiation dose of the voltage 100kV group was lower than that of the voltage 120kV group .Conclusion The quality of pictures of pulmonary artery ,coronary artery and aorta are not affected in different tube tension

  18. CT/FMT dual-model imaging of breast cancer based on peptide-lipid nanoparticles

    Science.gov (United States)

    Xu, Guoqiang; Lin, Qiaoya; Lian, Lichao; Qian, Yuan; Lu, Lisen; Zhang, Zhihong

    2016-03-01

    Breast cancer is one of the most harmful cancers in human. Its early diagnosis is expected to improve the patients' survival rate. X-ray computed tomography (CT) has been widely used in tumor detection for obtaining three-dimentional information. Fluorescence Molecular Tomography (FMT) imaging combined with near-infrared fluorescent dyes provides a powerful tool for the acquisition of molecular biodistribution information in deep tissues. Thus, the combination of CT and FMT imaging modalities allows us to better differentiate diseased tissues from normal tissues. Here we developed a tumor-targeting nanoparticle for dual-modality imaging based on a biocompatible HDL-mimicking peptide-phospholipid scaffold (HPPS) nanocarrier. By incorporation of CT contrast agents (iodinated oil) and far-infrared fluorescent dyes (DiR-BOA) into the hydrophobic core of HPPS, we obtained the FMT and CT signals simultaneously. Increased accumulation of the nanoparticles in the tumor lesions was achieved through the effect of the tumor-targeting peptide on the surface of nanoparticle. It resulted in excellent contrast between lesions and normal tissues. Together, the abilities to sensitively separate the lesions from adjacent normal tissues with the aid of a FMT/CT dual-model imaging approach make the targeting nanoparticles a useful tool for the diagnostics of breast cancer.

  19. Correlation of radiation dose and heart rate in dual-source computed tomography coronary angiography

    Energy Technology Data Exchange (ETDEWEB)

    Laspas, Fotios; Roussakis, Arkadios; Kritikos, Nikolaos; Efthimiadou, Roxani; Kehagias, Dimitrios; Andreou, John (CT and MRI Dept., Hygeia Hospital, Athens (Greece)), e-mail: fotisdimi@yahoo.gr; Tsantioti, Dimitra (Statistician, Hygeia Hospital, Athens (Greece))

    2011-04-15

    Background: Computed tomography coronary angiography (CTCA) has been widely used since the introduction of 64-slice scanners and dual-source CT technology, but the relatively high radiation dose remains a major concern. Purpose: To evaluate the relationship between radiation exposure and heart rate (HR), in dual-source CTCA. Material and Methods: Data from 218 CTCA examinations, performed with a dual-source 64-slices scanner, were statistically evaluated. Effective radiation dose, expressed in mSv, was calculated as the product of the dose-length product (DLP) times a conversion coefficient for the chest (mSv = DLPx0.017). Heart rate range and mean heart rate, expressed in beats per minute (bpm) of each individual during CTCA, were also provided by the system. Statistical analysis of effective dose and heart rate data was performed by using Pearson correlation coefficient and two-sample t-test. Results: Mean HR and effective dose were found to have a borderline positive relationship. Individuals with a mean HR >65 bpm observed to receive a statistically significant higher effective dose as compared to those with a mean HR =65 bpm. Moreover, a strong correlation between effective dose and variability of HR of more than 20 bpm was observed. Conclusion: Dual-source CT scanners are considered to have the capability to provide diagnostic examinations even with high HR and arrhythmias. However, it is desirable to keep the mean heart rate below 65 bpm and heart rate fluctuation less than 20 bpm in order to reduce the radiation exposure

  20. Relation between intravascular clots of pulmonary artery and lung perfusion defects: assessment with dual source CT low-dose contrast perfusion imaging%低剂量对比剂双能量肺灌注成像评估肺动脉内血栓与灌注缺损间的关系

    Institute of Scientific and Technical Information of China (English)

    沈比先; 谭四平; 彭冬红; 汪春荣; 贾飞鸽; 李元歌; 罗玉娟; 楚二伟

    2012-01-01

    目的:应用双源CT低剂量对比剂双能量肺灌注成像评估急性肺动脉栓塞患者血管内血栓与肺灌注缺损间的关系,以提高对肺动脉栓塞诊断的准确性.方法:随机选择无肺动脉栓塞患者的低剂量与常规剂量双能量肺灌注成像各15例,对比分析其图像质量;收集20例疑肺动脉栓塞患者行低剂量双能量肺灌注成像;同时获得肺动脉CTA及肺灌注图像.分析肺动脉内有无血栓.以及血栓的部位、数量及形态特征.用双能量肺灌注分析软件判断有无灌注缺损及缺损的部位、形态及范围.对比分析并统计肺动脉内血栓与肺灌注缺损间的关系.结果:肺动脉栓塞患者的低剂量与常规剂量双能量肺灌注成像质量无明显差异(P>0.05).20例疑似病例中,15例诊断为肺动脉栓塞,其中13例患者肺灌注图像中出现102个肺叶、肺段、或亚段灌注缺损,4例共6个灌注缺损CTA无明确血栓;11例肺动脉CTA显示43个血栓,其中9例血栓与灌注缺损同时存在,2例CTA共5个血栓肺内无灌注缺损.75个灌注缺损与栓塞肺动脉供血范围一致,21个灌注缺损(8段、13亚段)与肺动脉供血范围无关.结论:综合分析双源CT低剂量双能量肺灌注图与CTPA,可以提高肺动脉栓塞诊断的准确性.%Objective: To assess the relation between intravascular clots of pulmonary artery and lung perfusion defects with dual source CT low-dose contrast perfusion imaging so as to elevate the accuracy of diagnosis of PE. Methods: The image quality of low-dose and conventional dose dual energy lung perfusion imaging (DEPI) of patients without pulmonary embolism (PE). With 15 cases in each sose, were analyzed. Twenty consecutive patients with suspected PE underwent dual source CT low-dose contrast perfusion imaging and CT pulmonary angiography (CTPA) and lung perfusion images were aquired at the same time. The intravascular clots of pulmonary artery if or not, including the

  1. Relation between intravascular clots of pulmonary artery and lung perfusion defects: assessment with dual source CT low-dose contrast perfusion imaging%双源CT低剂量对比剂肺灌注成像评估肺动脉内血栓与灌注缺损间的关系

    Institute of Scientific and Technical Information of China (English)

    谭四平; 沈比先; 陈丽兴; 薛水培; 楚二伟; 刘康; 汪春荣; 贾飞鸽

    2012-01-01

    Objective: To assess the relation between intravascular clots of pulmonaiy artery and lung perfusion defects with dual source CT low-dose contrast perfusion imaging. Materials and Methods: Image quality of low-dose and conventional dose dual energy lung perfusion imaging (DEP1) in 15 patients without pulmonary embolism (PE) was analyzed. Twenty consecutive patients with suspected PE underwent dual source CT low-dose contrast perfusion imaging. CT pulmonary angiogra-phy (CTPA) and lung perfusion images were analyzed at the same time. Intravascular clots of pulmonary artery were analyzed,including the location,number and morphology by the axial image and three-dimensional reconstruction of CTPA. Lung perfusion defects and its location,extent were evaluated with lung PBV software on the workstation. The relationship between in-trava8Cular clots of pulmonary artery and lung perfusion defects were analyzed statistically. Results: No significant difference was found in the image quality of low-dose and conventional dose DEPI of patients without PE(P>0.05). One hundred and two perfusion defects were found in 13 patients by pulmonary perfusion imaging,including lobular,segmental and BubsegmentaJ perfusion defects. Six perfusion defects in 4 cases had no clear intravascular clots. Images of axial CTPA and three-dimensional reconstruction showed 43 intravascular clots in 11 patients. Two cases with 5 intravascular clots depicted by CTPA showed no perfusion defects. Nine cases showed both intravascular clots and perfusion defects,with 21 perfusion defects unrelated to the blood supply areas of pulmonary artery(8 segmental and 13 subsegmental),and the remaining 75 perfusion defects consistent with the blood supply areas of pulmonary artery. Conclusion: There is unexpected dissociation between the intravascular clots of pulmonary artery and lung perfusion defects. Analysing the perfusion maps and CTPA of dual source CT low-dose contrast perfusion image will improve the accuracy

  2. Phase contrast micro-CT with an ultrafast laser-based x-ray source

    Science.gov (United States)

    Toth, R.; Kieffer, J. C.; Krol, A.; Fourmaux, S.; Ozaki, T.; Ye, H.; Kincaid, R. E., Jr.; Rakhman, A.

    2005-08-01

    We investigated performance of ultrafast laser-based x-ray source for phase contrast imaging in 2D projection imaging and in enhanced micro-CT imaging. Good quality images were obtained, including images of small animals, in the single energy and multiple energy, in line phase-contrast enhancing geometry using x-ray line energy matching object thickness and density. Phase information has been inferred from images obtained at the same x-ray energy but at different object-to-detector distances and also from images obtained at the same object-to-detector distance but with different K-alpha line energies. Ultrafast laser-based, compact, x-ray source is a promising technique for micro-CT systems. Its utilization might result in faster scans with lower radiation dose, better spatial and contrast resolution and also femtosecond temporal resolution. In addition, it might allow practical implementation of dual-energy and phase-contrast imaging micro-CT that is not possible with conventional micro-CT.

  3. The applications of low tube voltage combined with dual-source CT new technology in early childhood chest examination%低管电压结合双源 CT 新技术在幼儿胸部检查中的应用研究

    Institute of Scientific and Technical Information of China (English)

    王宁; 孙建; 冯艳; 董景敏; 司晓静

    2014-01-01

    Objective To explore a more reasonable voltage parameters in early childhood chest examination with dual‐source CT new technology .Methods Selected 150 children product dual‐source CT chest scans which ages 1 to 3 years old ,the tube voltage of 80Kv group ( 50 cases ) ,100Kv group ( 50 cases ) ,120Kv group ( 50 cases ) ,with flash chest scan mode ,using real‐time online mA second adjustment techniques (CARE Dose 4D) and SAFIRE technology for image reconstruction .Two physi‐cians using 5‐point double‐blind method ,evaluated interobserver consistency with Kappa test ,recorded objective noise of ima‐ges ,CT dose index volume (CTDIvol) and dose length product (DLP) .Compared different voltage group subjective image quali‐ty ,objective noise and radiation dose .Results As the tube voltage value increased ,mediastinal and lung windows were improved image quality ,lung window image quality are more than four points ,able to meet the clinical diagnosis requires .Mediastinal win‐dow image score lower than the lung window ,which 80kV mediastinal image quality were less than 3 minutes ,unable to meet the diagnostic needs ,100kV and 120kV mediastinal image able to meet clinical needs .With tube voltage increases The objective noise significantly reduced .CT dose index volume ,dose length product value and the effective dose increases with the voltage in‐creased significantly .The group 80kV and 100kV CT dose index for the group 120kV of 24.2% ,55% .The group 80kV and 100kV effective dose for the group 120kV of 26.9% ,58.1% .Conclusion Chest examination with dual‐source CT in early childhood should be based on clinical needs to choose the right tube voltage .For lung and bronchial lesions ,80kV is able to meet clinical diagnostic needs and significantly reduce radiation measurement ,while for mediastinal lesions ,you need to select a high‐er tube voltage value .%目的:探讨应用双源C T新技术后,在幼儿胸部检查中较为合理

  4. Dual-energy micro-CT imaging of pulmonary airway obstruction: correlation with micro-SPECT

    Science.gov (United States)

    Badea, C. T.; Befera, N.; Clark, D.; Qi, Y.; Johnson, G. A.

    2014-03-01

    To match recent clinical dual energy (DE) CT studies focusing on the lung, similar developments for DE micro-CT of the rodent lung are required. Our group has been actively engaged in designing pulmonary gating techniques for micro- CT, and has also introduced the first DE micro-CT imaging method of the rodent lung. The aim of this study was to assess the feasibility of DE micro-CT imaging for the evaluation of airway obstruction in mice, and to compare the method with micro single photon emission computed tomography (micro-SPECT) using technetium-99m labeled macroaggregated albumin (99mTc-MAA). The results suggest that the induced pulmonary airway obstruction causes either atelectasis, or air-trapping similar to asthma or chronic bronchitis. Atelectasis could only be detected at early time points in DE micro-CT images, and is associated with a large increase in blood fraction and decrease in air fraction. Air trapping had an opposite effect with larger air fraction and decreased blood fraction shown by DE micro-CT. The decrease in perfusion to the hypoventilated lung (hypoxic vasoconstriction) is also seen in micro-SPECT. The proposed DE micro-CT technique for imaging localized airway obstruction performed well in our evaluation, and provides a higher resolution compared to micro-SPECT. Both DE micro-CT and micro-SPECT provide critical, quantitative lung biomarkers for image-based anatomical and functional information in the small animal. The methods are readily linked to clinical methods allowing direct comparison of preclinical and clinical results.

  5. Small hepatocellular carcinoma with peripheral enhancement:pathological correlation with dual phase images by helical CT

    Institute of Scientific and Technical Information of China (English)

    ZHENG Ke-guo; SHEN Jing-xian; WANG Gen-shu; XU Da-sheng

    2007-01-01

    Background The peripheral enhancement of small hepatocellular carcinoma (SHCC) is a rare appearance in dual phase images by helical computed tomography (CT). This study discusses this phenomenon and its correlative histopathology.Methods The helical CT dual phase appearance of peripheral enhancement in SHCC was analyzed in 21 cases (22 lesions). All lesions were confirmed as SHCC by histopathological examination.Results In these 22 lesions, enhanced peripheral ring in 20 lesions was incomplete, the thickness of enhanced peripheral ring varied and mural node could be found in hepatic arterial phase; only 2 lesions had complete peripheral ring enhancement and ring of uniform thickness in hepatic arterial phase. The enhancement of some peripheral rings and mural nodes dropped to very low density in portal venous phase. The tumour cells were grade Ⅰ in 3 lesions, Ⅱ in 16, Ⅲ in 2 and Ⅳ in 1. The vascular supply was more abundant at the border than in the centre of 15 lesions and the vascular supply was deficient in both centre and border of the remaining 7 lesions. In 3 lesions, the pseudocapsule showed in the border of the lesion. In 12 lesions, flecks of necrosis were found in the border and/or centre of the lesion.Conclusions The characteristic peripheral enhancement in helical CT dual phase images of small hepatocellular carcinoma correlates with different vascular supplies, fibrous capsule and necrosis of the lesion.

  6. Cost Analysis for Dual Source Weapon Procurement

    Science.gov (United States)

    1983-10-01

    34,- art seems to be regrettably trueý (1981: p. 52] Current uudersta~iinq of the compatitive r~pro- curement process is meagar. it would for ixam- ple be...the- art will be organized by section, according to the following major topics: ’I. Production Rates 2. Second-Source Start-Up Cost 3. Second-Source...when capaci- , ty utilization is Low. The returns earned by contractors on DOD business are measurably lower than the returns on com- marcial business

  7. Split-bolus CT-urography using dual-energy CT: Feasibility, image quality and dose reduction

    Energy Technology Data Exchange (ETDEWEB)

    Takeuchi, Mitsuru, E-mail: m2rbimn@gmail.com [Nagoya City University Graduate School of Medical Sciences, Department of Radiology, 1 Kawasumi Mizuho-cho, Mizuho-ku, Nagoya, 467-8601 (Japan); Kawai, Tatsuya; Ito, Masato; Ogawa, Masaki [Nagoya City University Graduate School of Medical Sciences, Department of Radiology, 1 Kawasumi Mizuho-cho, Mizuho-ku, Nagoya, 467-8601 (Japan); Ohashi, Kazuya [Nagoya City University Hospital, Department of Radiology, 1 Kawasumi Mizuho-cho, Mizuho-ku, Nagoya, 467-8601 (Japan); Hara, Masaki; Shibamoto, Yuta [Nagoya City University Graduate School of Medical Sciences, Department of Radiology, 1 Kawasumi Mizuho-cho, Mizuho-ku, Nagoya, 467-8601 (Japan)

    2012-11-15

    Purpose: To prospectively evaluate the feasibility of dual-energy (DE) split-bolus CT-urography (CTU) and the quality of virtual non-enhanced images (VNEI) and DE combined nephrographic-excretory phase images (CNEPI), and to estimate radiation dose reduction if true non-enhanced images (TNEI) could be omitted. Patients and methods: Between August and September 2011, 30 consecutive patients with confirmed or suspected urothelial cancer or with hematuria underwent DE CT. Single-energy TNEI and DE CNEPI were obtained. VNEI was reconstructed from CNEPI. Image quality of CNEPI and VNEI was evaluated using a 5-point scale. The attenuation of urine in the bladder on TNEI and VNEI was measured. The CT dose index volume (CTDI (vol)) of the two scans was recorded. Results: The mean image quality score of CNEPI and VNEI was 4.7 and 3.3, respectively. The mean differences in urine attenuation between VNEI and TNEI were 14 {+-} 15 [SD] and -16 {+-} 29 in the anterior and posterior parts of the bladder, respectively. The mean CTDI (vol) for TNEI and CNEPI was 11.8 and 10.9 mGy, respectively. Omission of TNEI could reduce the total radiation dose by 52%. Conclusion: DE split-bolus CTU is technically feasible and can reduce radiation exposure; however, an additional TNEI scan is necessary when the VNEI quality is poor or quantitative evaluation of urine attenuation is required.

  8. 双源螺旋CT灌注孤立性肺结节的诊断技术及临床价值分析%The Analysis on Diagnosis Technology and Clinical Value of Perfusion Solitary Pulmonary Nodules of Dual Source Spiral CT

    Institute of Scientific and Technical Information of China (English)

    李雪萍; 刘彪; 黄波; 毛健强; 莫家强; 黄伟兰; 梁岳杰

    2014-01-01

    目的:研究比较双源螺旋CT灌注成像对于孤立性肺结节(SPN)良恶性的诊断价值及临床应用。方法对于我院2011年11月至2013年12月50例未经治疗的直径≤3.0cm的肺孤立结节根据病理结果分为恶性结节组和良性结节组,分别进行双源螺旋CT灌注成像,计算结节的血流量(BF)、血容量(BV)、平均通过时间(MTT)和通透性值(Permeability,PMB)。同时绘制同层面结节的时间-密度曲线(TAC),判断结节良恶性,和手术病理结果进行对比分析,计算各灌注参数对于孤立性肺结节良恶性诊断的准确率、敏感性和特异性。结果经CT引导下肺穿刺活检或手术病理证实,发现恶性结节34例,良性结节16例。两组结节的各灌注参数差异显著, P<0.01;同层面结节的TAC曲线良恶性差异显著,有助于提示结节性质,血容量(BV)、平均通过时间(MTT)、血流量(BF)和通透性值(PMB)对于孤立性肺结节良恶性诊断的准确率、敏感性和特异性分别为88%,88.24%,87.50%;90%,94.12%,%Objective research and compare the diagnosis value and clinical application of optimum and malignant influence of dual source spiral CT perfusion imaging on solitary pulmonary nodules (SPN). Methods According to the pathological results, the 50 cases of untreated solitary pulmonary nodules with Diameter of≤3.0cm from November 2011 to December 2013 can be divided into malignant nodules group and benign nodules group, and conduct dual source spiral CT perfusion imaging on each group, calculate the blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability (PMB) of nodules. At the same time, draw the time-density curve in the same level node (TAC) to judge the optimum and malignant influence of nodules and the operation pathology results to conduct compare and analysis, calculate the accuracy, sensitivity and specificity of each perfusion parameters on the malignant and benign

  9. Dual-energy CT of the heart for diagnosing coronary artery stenosis and myocardial ischemia-initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Ruzsics, Balazs; Costello, Philip [Medical University of South Carolina, Department of Radiology, Charleston, SC (United States); Lee, Heon [Medical University of South Carolina, Department of Radiology, Charleston, SC (United States); Seoul Medical Center, Department of Radiology, Seoul (Korea); Zwerner, Peter L.; Schoepf, U.J. [Medical University of South Carolina, Department of Radiology, Charleston, SC (United States); Medical University of South Carolina, Division of Cardiology, Charleston, SC (United States); Gebregziabher, Mulugeta [Medical University of South Carolina, Department of Biostatistics, Bioinformatics, and Epidemiology, Charleston, SC (United States)

    2008-11-15

    We aimed to evaluate the feasibility of diagnosing coronary stenosis and myocardial ischemia with a single dual-energy CT (DECT) acquisition. Thirty-five patients underwent contrast-enhanced, ECG-gated DECT of the heart while independently operating the two tubes of a dual-source CT system at high- and low-energy X-ray spectra. From the same raw data, coronary CTA (cCTA) studies were reconstructed for stenosis detection, and the myocardial blood-pool was analyzed by determining the tissue iodine content. Two independent observers analyzed all studies for stenosis and myocardial blood-pool deficits. Results were correlated with SPECT, coronary catheterization and cCTA on a segmental basis. cCTA had 98% sensitivity, 88% specificity and 92% accuracy for detection of >50% stenosis. DECT detected myocardial ischemia with 84% sensitivity, 94% specificity and 92% accuracy. Our initial experience may warrant further exploration of DECT as a possibly feasible single imaging investigation for the comprehensive diagnosis of coronary stenosis and myocardial ischemia. (orig.)

  10. Utility of iodine overlay technique and virtual unenhanced images for the characterization of renal masses by dual-energy CT.

    Science.gov (United States)

    Song, Kyoung Doo; Kim, Chan Kyo; Park, Byung Kwan; Kim, Bohyun

    2011-12-01

    The objective of our study was to assess the utility of dual-energy CT for characterizing renal masses using iodine overlay techniques and virtual unenhanced images and to measure the potential radiation dose reduction for two-phase kidney CT compared with a standard three-phase protocol. Sixty patients with suspected renal masses underwent dual-energy CT including true unenhanced, dual-energy corticomedullary, and dual-energy late nephrographic phase imaging. Iodine overlay and virtual unenhanced images were derived from the corticomedullary and late nephrographic phases, respectively. The CT numbers of renal masses were calculated using the iodine overlay images superimposed on the virtual unenhanced images. The overall imaging quality of the true unenhanced images and of the virtual unenhanced images was also evaluated. The effective radiation doses for dual-energy CT and for true unenhanced imaging were calculated. For overlay or enhancement values on iodine overlay images, 36 simple cysts and 10 hemorrhagic cysts had an attenuation value of less than 20 HU, whereas 21 renal cell carcinomas showed an attenuation value of 20 HU or greater. Eleven angiomyolipomas contained macroscopic fat tissue. All renal masses were accurately classified on the basis of dual-energy CT. The imaging quality of the virtual unenhanced images from the corticomedullary and late nephrographic phases was inferior to the image quality of the true unenhanced images (p overlay techniques and virtual unenhanced images may be useful for characterizing renal masses.

  11. Potential Sources of Bias in Dual Language Achievement Tests.

    Science.gov (United States)

    Cabello, Beverly

    Potential sources of bias in dual language achievement tests were identified and examined. Content, concepts, and vocabulary presented in monolingual English curricula may differ drastically from those presented in bilingual curricula. The Spanish or English versions of the Comprehensive Tests of Basic Skills (CTBS) were administered to 1259…

  12. The role of dual-phase helical CT in assessing resectability of carcinoma of the gallbladder

    Energy Technology Data Exchange (ETDEWEB)

    Kumaran, Vinay; Pande, Girish Kumar; Sahni, Peush; Chattopadhyay, Tushar Kanti [Department of Gastrointestinal Surgery, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110 029 (India); Gulati, Manpreet Singh; Paul, Shashi Bala [Department of Radiodiagnosis, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110 029 (India)

    2002-08-01

    Our objective was to assess the ability of dual-phase helical CT (DHCT) to predict resectability of carcinoma of gallbladder (CaGB). Thirty-two consecutive patients suspected of having CaGB on clinical examination and sonography presented to our centre over 10-month period. All these 32 patients underwent DHCT. Fifteen patients were considered inoperable and 2 had xanthogranulomatous cholecystitis. The remaining 15 patients (10 women, 5 men; age range 33-72 years) underwent surgery and had histopathological confirmation of CaGB and were included in the study based on the following criteria: presence of mass in gallbladder fossa on sonography and DHCT, and confirmation at surgery and histopathological examination. Axial reconstructions of 2 mm were obtained (collimation 3 mm, table speed 4.5 mm/s) for arterial (scan delay 20 s) and venous (scan delay 60 s) phases on a helical scanner. The criteria used for unresectability were: distant metastasis (liver, peritoneum, lymph nodes), extensive local contiguous organ spread, involvement of secondary biliary confluence of both lobes of liver, tumoral invasion of main portal vein, or proper hepatic artery or simultaneous invasion of one side hepatic artery and the other side portal vein. The CT findings related to unresectability were correlated with surgical findings. On the basis of CT findings, 10 patients were unresectable and 5 were resectable. Of the 10 patients considered unresectable, 9 had tumours that were unresectable at surgery (sensitivity 100%, positive predictive value 90%). Five patients had more than one reason and 4 had one reason alone for being unresectable (lymph nodes, n=2; hepatic metastasis, n=1; and vascular invasion, n=1). All 5 patients considered resectable based on CT findings had resectable tumours at surgery (negative predictive value 100%). The overall accuracy of CT was 93.3%. Dual-phase helical CT comprehensively evaluates CaGB and may be a useful tool in preoperative staging of this

  13. Dual energy CT: How well can pseudo-monochromatic imaging reduce metal artifacts?

    Energy Technology Data Exchange (ETDEWEB)

    Kuchenbecker, Stefan, E-mail: stefan.kuchenbecker@dkfz.de; Faby, Sebastian; Sawall, Stefan; Kachelrieß, Marc [German Cancer Research Center (DKFZ), Heidelberg 69120 (Germany); Lell, Michael [Friedrich-Alexander-University (FAU), Erlangen 91054 (Germany)

    2015-02-15

    Purpose: Dual Energy CT (DECT) provides so-called monoenergetic images based on a linear combination of the original polychromatic images. At certain patient-specific energy levels, corresponding to certain patient- and slice-dependent linear combination weights, e.g., E = 160 keV corresponds to α = 1.57, a significant reduction of metal artifacts may be observed. The authors aimed at analyzing the method for its artifact reduction capabilities to identify its limitations. The results are compared with raw data-based processing. Methods: Clinical DECT uses a simplified version of monochromatic imaging by linearly combining the low and the high kV images and by assigning an energy to that linear combination. Those pseudo-monochromatic images can be used by radiologists to obtain images with reduced metal artifacts. The authors analyzed the underlying physics and carried out a series expansion of the polychromatic attenuation equations. The resulting nonlinear terms are responsible for the artifacts, but they are not linearly related between the low and the high kV scan: A linear combination of both images cannot eliminate the nonlinearities, it can only reduce their impact. Scattered radiation yields additional noncanceling nonlinearities. This method is compared to raw data-based artifact correction methods. To quantify the artifact reduction potential of pseudo-monochromatic images, they simulated the FORBILD abdomen phantom with metal implants, and they assessed patient data sets of a clinical dual source CT system (100, 140 kV Sn) containing artifacts induced by a highly concentrated contrast agent bolus and by metal. In each case, they manually selected an optimal α and compared it to a raw data-based material decomposition in case of simulation, to raw data-based material decomposition of inconsistent rays in case of the patient data set containing contrast agent, and to the frequency split normalized metal artifact reduction in case of the metal

  14. The HelCat dual-source plasma device.

    Science.gov (United States)

    Lynn, Alan G; Gilmore, Mark; Watts, Christopher; Herrea, Janis; Kelly, Ralph; Will, Steve; Xie, Shuangwei; Yan, Lincan; Zhang, Yue

    2009-10-01

    The HelCat (Helicon-Cathode) device has been constructed to support a broad range of basic plasma science experiments relevant to the areas of solar physics, laboratory astrophysics, plasma nonlinear dynamics, and turbulence. These research topics require a relatively large plasma source capable of operating over a broad region of parameter space with a plasma duration up to at least several milliseconds. To achieve these parameters a novel dual-source system was developed utilizing both helicon and thermionic cathode sources. Plasma parameters of n(e) approximately 0.5-50 x 10(18) m(-3) and T(e) approximately 3-12 eV allow access to a wide range of collisionalities important to the research. The HelCat device and initial characterization of plasma behavior during dual-source operation are described.

  15. The Research and Solution Scheme on Relationship between Dual-Source CT Coronary Artery CTA Artifact and Heart Rate Change%双源CT冠状动脉CTA伪影与心率变化关系探讨和解决对策

    Institute of Scientific and Technical Information of China (English)

    冀舒文; 巢惠民; 高斌; 陈旺

    2011-01-01

    目的:研究双源CT成像质量和错层伪影出现原因,探讨成像质量不佳的原因和解决方法。方法:回顾性分析自2010年2月至2010年6月70例临床疑似冠心病人双源CT冠状动脉CTA图像和心电监测资料。比较出现错层伪影和无错层伪影的病人的平均心率、心率波动、心率变异和平均R-R间期的差异。结果:出现错层伪影和无错层伪影病人的平均心率、心率波动、心率变异和平均R-R间期没有显著性差异。结论:在双源CT使用中,平均心率、心率波动、心率变异、平均R-R间期等参数不是直接或主要导致图像质量不佳和错层伪影的主要原因,这与双源CT的设备性能和数据采集方式有关。导致图像伪影的原因是心律不齐、扫描过程中的体位移动,出现伪影后进行心电编辑重新发现和选择不同心动周期心脏运动相位相同的重建时间窗可以纠正错层伪影。%Purpose:The reason of imaging quality and wrong layer artifact of coronary arteries CTA with Dual-source CT and heart rate and to discuss the reason of poor imaging quality and the solution.Method:70 cases of coronary arteries CTA imaging and ECG data of patients with suspected coronary artery disease from February 2010 to July 2010 were retrospectively analyzed.The difference of average heart rate,fluctuation of heart rate,variation of heart rate and average R-R period between the patients who has artifact and no artifact was compared.Results:Average heart rate,fluctuation of heart rate,variation of heart rate and average R-R period between the patients who has artifact and no artifact is no significant difference.Conclusion:Use in the double source CT in,average heart rate,heart rate motion,heart rate variation and average R-R expect to etc.parameter to isn't direct or mainly cause picture quality poor and wrong layer false shadow of main reason,this and double equipments function and data of the source CT

  16. Influence of individualized nursing intervention on success rate of holding breathing in patients undergoing dual-source CT imaging%个性化护理干预对双源CT冠状动脉成像中患者闭气成功率影响的研究

    Institute of Scientific and Technical Information of China (English)

    王颖

    2011-01-01

    目的 探讨个性化护理干预对提高双源CT冠状动脉成像中患者闭气成功率的影响。方法 将167例患者随机分为观察组100例与对照组67例。对照组实行常规护理,观察组在常规护理的基础上,针对闭气易失败的原因进行个性化护理干预,包括做好心理疏导,给予耐心、正确的指导,改善疾病症状,提升舒适度,检查后进行疗效评价等手段。比较2组的闭气成功率。结果 观察组和对照组的闭气成功率分别为99.0%和88.1%,观察组成功率明显高于对照组。结论 对患者进行健康宣教,注意患者病情、心理、认知及行为变化,适时地给予个性化护理干预,并认真检查患者实施效果,可有效提高双源CT冠状动脉成像中患者闭气成功率。%Objective To discuss the infiuence of personalized nursing intervention on success rate of holding breathing in patients undergoing dual-source CT imaging. Methods 167 cases of patients were randomly divided into the observation group(100 cases)and the control group(67 cases). The control group implemented routine care, on the basis of routine care, the observation group was given pertinent and individualized nursing intervemion according to the factors causing failure of holding breathing, including better psychological counseling for patients, the right guidance, to alleviate symptoms, to improve comfort degree, to give clinical evaluation after inspection, et al. Results The success rate of holding breathing in the observation group and the control group was 99.0% and 88.1%, the observation group was significantly higher than the control group. Conclusions Health education for patients, attention to patients' illness, mental state, cognitive and behavioral changes in a timely manner to give individualized nursing intervention and seriously check the implementation of results in patients, can effectively improve the success rate of holding breathing

  17. On two-parameter models of photon cross sections: application to dual-energy CT imaging.

    Science.gov (United States)

    Williamson, Jeffrey F; Li, Sicong; Devic, Slobodan; Whiting, Bruce R; Lerma, Fritz A

    2006-11-01

    The goal of this study is to evaluate the theoretically achievable accuracy in estimating photon cross sections at low energies (20-1000 keV) from idealized dual-energy x-ray computed tomography (CT) images. Cross-section estimation from dual-energy measurements requires a model that can accurately represent photon cross sections of any biological material as a function of energy by specifying only two characteristic parameters of the underlying material, e.g., effective atomic number and density. This paper evaluates the accuracy of two commonly used two-parameter cross-section models for postprocessing idealized measurements derived from dual-energy CT images. The parametric fit model (PFM) accounts for electron-binding effects and photoelectric absorption by power functions in atomic number and energy and scattering by the Klein-Nishina cross section. The basis-vector model (BVM) assumes that attenuation coefficients of any biological substance can be approximated by a linear combination of mass attenuation coefficients of two dissimilar basis substances. Both PFM and BVM were fit to a modern cross-section library for a range of elements and mixtures representative of naturally occurring biological materials (Z = 2-20). The PFM model, in conjunction with the effective atomic number approximation, yields estimated the total linear cross-section estimates with mean absolute and maximum error ranges of 0.6%-2.2% and 1%-6%, respectively. The corresponding error ranges for BVM estimates were 0.02%-0.15% and 0.1%-0.5%. However, for photoelectric absorption frequency, the PFM absolute mean and maximum errors were 10.8%-22.4% and 29%-50%, compared with corresponding BVM errors of 0.4%-11.3% and 0.5%-17.0%, respectively. Both models were found to exhibit similar sensitivities to image-intensity measurement uncertainties. Of the two models, BVM is the most promising approach for realizing dual-energy CT cross-section measurement.

  18. Motion correction for improving the accuracy of dual-energy myocardial perfusion CT imaging

    Science.gov (United States)

    Pack, Jed D.; Yin, Zhye; Xiong, Guanglei; Mittal, Priya; Dunham, Simon; Elmore, Kimberly; Edic, Peter M.; Min, James K.

    2016-03-01

    Coronary Artery Disease (CAD) is the leading cause of death globally [1]. Modern cardiac computed tomography angiography (CCTA) is highly effective at identifying and assessing coronary blockages associated with CAD. The diagnostic value of this anatomical information can be substantially increased in combination with a non-invasive, low-dose, correlative, quantitative measure of blood supply to the myocardium. While CT perfusion has shown promise of providing such indications of ischemia, artifacts due to motion, beam hardening, and other factors confound clinical findings and can limit quantitative accuracy. In this paper, we investigate the impact of applying a novel motion correction algorithm to correct for motion in the myocardium. This motion compensation algorithm (originally designed to correct for the motion of the coronary arteries in order to improve CCTA images) has been shown to provide substantial improvements in both overall image quality and diagnostic accuracy of CCTA. We have adapted this technique for application beyond the coronary arteries and present an assessment of its impact on image quality and quantitative accuracy within the context of dual-energy CT perfusion imaging. We conclude that motion correction is a promising technique that can help foster the routine clinical use of dual-energy CT perfusion. When combined, the anatomical information of CCTA and the hemodynamic information from dual-energy CT perfusion should facilitate better clinical decisions about which patients would benefit from treatments such as stent placement, drug therapy, or surgery and help other patients avoid the risks and costs associated with unnecessary, invasive, diagnostic coronary angiography procedures.

  19. 对比剂碘浓度在双源双能量CT检查中对血管和肝脏强化的影响%Effect of different iodine concentrations of contrast material on the vascu-lar and hepatic enhancement during dual-source dual-energy CT

    Institute of Scientific and Technical Information of China (English)

    赵林伟; 董国礼; 杨国庆; 赵秀华; 冯敏

    2016-01-01

    Objective:To compare vascular and parenchymal contrast enhancement in dual-energy CT of the liver using two contrast media with different iodine concentration (iopamidol 300 mgI /mL and 370 mgI /mL),use of a protocol with iodine dose adjus-ted for the patient’s body surface area com-(BSA;17.1 gI /m2 BSA)and fixed injection duration (25 s).Methods:300 patients were prospectively randomized into four groups.Patients in groups A and C received iopamidol with an iodine concentration of 300mg I /mL, B and D received iopamidol with an iodine concentration of 370mg I /mL respectively.Iodine dose was adjusted according to BSA,with a fixed injection duration of 25 s.Dual-energy acquisition mode was performed during late hepatic-arterial phase(A,B)and portal ve-nous phase(C,D).Enhancement of the abdominal aorta,liver and portal vein were compared between high-concentration contrast medi-um and low-concentration contrast medium at 80kVp,140kVp and color-coded iodine overlay images.The Mann-Whitney U test was used to enhance the difference between group.Results:At 80kVp,140kVp or color-coded iodine overlay images,the mean contrast en-hancement of the aorta was a trend towards higher contrast enhancement during the hepatic arterial phase,which was not statistically sig-nificant,when the higher concentration contrast medium was injected.And there was no significant difference between two iodine con-centration contrast medium for the mean contrast enhancement of the portal vein during the hepatic portal venous phase and for the mean contrast enhancement of the hepatic parenchyma during each acquisition phase (P >0.05).Conclusion:With fixed injection duration (25 s)and iodine load being tailored according to BSA,comparable contrast enhancement can be achieved with 300mg I /mL and 370mg I /mL being injected in liver enhanced DECT imaging.%目的:根据体表面积(body surface area,BSA)调整碘剂量(17.1 gI /m2 BSA)、固定注射时间(25 s),比较双能量CT(dual

  20. Design Consideration and Reconstruction Method for Double-source Double-multislice Spiral CT

    Institute of Scientific and Technical Information of China (English)

    LIU Zun-gang; ZHAO Jun; ZHUANG Tian-ge

    2007-01-01

    To accelerate the scan speed and improve the image quality, a new type of CT configuration, "doublesource double-multislice spiral CT" (DSDMS-CT), which is based on two sets of single-source multislice spiral CT was proposed with a special reconstruction algorithm.Simulation results using the fan-beam filtered backprojection algorithm with a special interpolation method were presented for both single-source multislice spiral CT and DSDMS-CT.The results of new CT model show that it scans faster than the traditional spiral CT and has a better slice sensitivity profile (SSP) with larger pitch value.

  1. Optimization of kV Selection on Third-generation High-pitch Dual-source Coronary CT Angiography Using Ultra-low Contrast Media Protocols in Patients with Body Mass Index between 20-30 kg/m(2) under Automatic Tube Voltage Selection.

    Science.gov (United States)

    Wang, Ming; Yi, Yan; Cao, Jian; Wang, Yining; Qi, Bing; Ma, Shuo; Wang, Yun

    2017-02-20

    Objective To investigate the application of automatic tube voltage selection (CARE-kV)coronary CT angiography (CCTA)using ultra-low contrast media (CM)protocols in patients with body mass index (BMI)between 20 kg/m(2) and 30 kg/m(2) on third-generation dual-source CT (DSCT). Methods We prospectively included 134 consecutive patients with BMI between 20 kg/m(2) and 30 kg/m(2)who underwent CARE-kV prospective high-pitch CCTA on third-generation DSCT using the ultra-low CM protocols and divided them into two groups according to the CARE-kV results:70 kV group(n=91):65 patients with normal BMI(20 kg/m(2)≤BMI≤25 kg/m(2))and 26 patients with high BMI(25 kg/m(2)image quality (IQ),and results of patients in each group and subgroup were evaluated and compared.ResultsThe ED of 70 kV group was(0.24±0.04)mSv,which was 53% lower(H=3.37,P=0.02)than that of 80 kV group [(0.51±0.05)mSv]. No significant difference of CNR and SNR had been found in normal BMI patients(H=1.81,P=0.23)and high BMI patients (H=0.91,P=0.84)among 70 kV group and 80 kV group,as well as the subjective IQ in normal BMI patients(Z=0.79,P=0.76)and high BMI patients (Z=0.77,P=0.81)among 70 kV group and 80 kV group. Conclusion sWhen patients with BMI between 20 kg/m(2) and 30 kg/m(2) receive CARE-kV prospective high-pitch CCTA on third-generation DSCT,the CARE-kV results for a portion of patients may be higher than other patients with the same BMI level,so as to guarantee the equivalent IQ. The CARE-kV can help to select the patients' optimal tube voltage value more accurately and reasonably.

  2. 双源CT前瞻性心电门控扫描在急性胸痛诊断中应用的可行性%Feasibility of Prospective EGG-Dual-Source CT in the Diagnosis of Patients with Acute Chest Pain

    Institute of Scientific and Technical Information of China (English)

    陈丹; 周嘉慧; 史雅文

    2012-01-01

    Objective To evaluate the feasibility of prospective ECG gated dual-source CT (DSCT)in patients with acute chest pain in different heart rate. Methods Forty two patients with acute chest pain underwent prospective ECG-ga ted DSCT scan. The patients were divided into two groups. In group A, the heart rate of patients was = 75 beats / min, data set was reconstructed in 70% R-R interval, ECG pulse window was set to 62% -78% . In group B, the heart rate of patients was > 75 beats / min, data set was reconstructed in 40% R-R interval, ECG pulse window was set to 32% -48%. Two experienced radiologists assessed the image quality of two groups, The images were target reconstructed on pul monary artery, aorta, coronary arteries, and the radiation dose was calculated. \\2 test was used to explore significant differ ences in assessable segments coronary artery . Two independent samples t-test was used to explore significant differences in vessel attenuation of ascending aorta and pulmonary trunk. As well as, the CT coronary angiographic images of 16 cases were compared with DSA. Results Only one case, the attenuation of ascending aorta did not meet the diagnostic criteria. The attenuation of ascending aorta and pulmonary trunk had not statistical difference between group A and B (t values were 0.254,0. 700, P values were > 0. 05). The assessable segments of coronary arteries of group A and B were 278/284 (97. 89% ) , 297/307 {96. 74% ) , and there was no statistical difference between two groups. There was good consistency between CT coronary angiographic images and DSA images. The average effective dose was (8. 67 ±2. 54)mSv. Conclu sion Prospective ECG gated DSCT angiography offers a very good image quality without heart rate control in patients with acute chest pain.%目的 探讨应用双源CT( dual-source CT,DSCT)前瞻性心电门控扫描对不同心率的急性胸痛患者诊断的可行性.方法 对42例急性胸痛患者进行DSCT前瞻性心电门控心胸联合

  3. Correlation between contrast enhancement of portal vein and spleen size in dual-phase spiral CT

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Seung Eon; Choi, Jong Cheol; Nam, Kyung Jin; Jung, Won Jung; Goo, Bong Sik; Park, Byung Ho; Lee, Young Ii; Chung, Duck Hwan [Donga Univ. College of Medicine, Pusan (Korea, Republic of)

    1996-10-01

    To evaluate using spiral CT the effect of spleen size on blood flow in the portal venous system and to know the usefulness of this evaluation. Fifty-one patients without evidence on spiral CT scan of abnormality thought to affect portal venous flow presented between December 1994 and June 1995. We measured spleen size and Hounsfield units of portal vein in dual-phase, and calculated the ratio of the unit in the portal phase to that in the arterial phase. Spleen size was measured, using the length of X-axis by that of Z-axis on spiral CT scan. We then measured the correlation between the two values. CT was performed with a Somatom Plus-S scanner(Siemens, Erlangen, Germany). A total dose of 120ml of non-ionic contrast material(Ultravist) was administered at a rate of 3 ml/sec. Arterial and portal phase were obtained after 30 seconds and 60 seconds from the begining of the contrast agent injection. The correlation between spleen size and contrast enhancement of the portal vein was relatively significant(Pearson's correlation coefficient(r)=0.41801). Spleen size significantly affects portal venous flow on spiral CT scan. The evaluation of spleen size and contrast enhancement of the portal vein could be useful in the differential diagnosis of diseases which affect portal venous flow.

  4. 双源光子CT大螺距、低辐射剂量、低对比剂用量扫描方案在主动脉夹层病变中的应用%The Application of Dual-source Single Photons CT with Big Pitch, Low Radiation Dose and Low Contrast Agent in Lesions Such as the Aortic Dissection

    Institute of Scientific and Technical Information of China (English)

    邹新华; 李文武

    2016-01-01

    目的 总结双源光子CT单能大螺距、低辐射剂量、低对比剂用量扫描方案在主动脉夹层病变中的应用价值.方法 对临床怀疑主动脉夹层病变的患者行双源光子CT血管造影,随机使用大螺距扫描方案及回顾性门控标准技术扫描方案进行扫描.观察及分析胸腹主动脉病变,有无夹层、夹层破口的位置及数目等,对比这两种扫描方案的图像质量、辐射剂量、对比剂用量差异.结果 两种扫描方案得到的图像均可清晰显示主动脉夹层的破口、内膜片、撕裂范围、各主要功能血管的累及情况.A组与B组扫描范围差异无显著性意义.两组的重建及重组图像质量均达优化标准.A组扫描时间约(1.37±0.19)s,B组扫描时间约(14.23±2.01)s,A组辐射剂量为(4.59±0.88)mSv,B组辐射剂量为(15.95±0.99)mSv,A组造影剂用量为(55±5)ml,B组造影剂用量为(85±5)ml,两组差异有显著性意义.结论 双源光子CT大螺距、低辐射剂量、低对比剂用量扫描方案对主动脉夹层病变的检查及诊断更具优势.%Objective To conclude the application value of dual-source single photons CT with low dose and low -dose contrast agent in chest aortic lesions.Methods Patients suspected aortic dissection in clinical are designed to do dual-source CT angiography, using big pitch scanning solutions or retrospective gating standard scanning technology to scan randomly. Then to observe and analyze the aortic disease in chest and abdomen,with or without dissection, the location and number of interlayer crevasse, the scope of tear, diaphragm, whether the main functional vascular are involved, with or without intramural hematoma, penetrating ulcer and aneurysm. At last, contrast the differences among the image quality, radiation dose and dosage of contrast agent of the two scanning modes.Results Both ways can show the location and number of interlayer crevasse, diaphragm,the scope of tear, whether the main

  5. Diagnostic value of dual-source CT perfusion imaging and serum makers in the evaluation stage of liver fibrosis%双源CT 灌注成像联合血清学指标对肝纤维化诊断的价值探讨

    Institute of Scientific and Technical Information of China (English)

    谭凡; 聂聪科; 王皓; 王红; 王云玲; 贾文霄

    2014-01-01

    目的:探讨双源CT灌注成像联合血清学指标对兔肝纤维化进行早期诊断的价值。方法采用四氯化碳法建立肝纤维化模型,共对46只肝纤维化成模兔及10只对照兔行灌注成像,取得不同肝纤维化级别肝灌注参数,包括:肝动脉灌注量(ALP)、门脉灌注量(PVP)、肝动脉灌注指数(HPI)、血流量(BF)、血容量(BV)。检测肝纤维化兔血清透明质酸(H A )、Ⅲ型前胶原(PCⅢ)、IV型胶原(IV‐C )和层黏连蛋白(L N )值,随后行病检分期分组,分析组间灌注参数值,同时分析灌注参数及血清学指标与肝纤维化程度的相关性。结果随着肝纤维化分期增加,PV P值呈下降趋势( P <0.05);S0、S1期分别与S2、S3、S4期具有统计学差异( P <0.05);PVP、HPI与肝纤维化分期存在一定相关性( r =‐0.84,P <0.05;r =0.62,P <0.05)。血清学指标随着肝纤维化程度加重而逐渐升高,其中,HA、IV‐C与肝纤维化分期关系较为密切( P<0.05)。结论双源CT灌注成像与血清学检查在判断肝纤维化程度各有优缺点,联合应用二者有助于临床对肝纤维化进行合理评价。%Objective To explore the value of evaluating the early stage of liver fibrosis using dual‐source CT perfusion paramaters and serum makers .Methods Intraperitoneal injection of CCl4 was used to induce liver fibrosis .46 rabbits in experimental group and 10 rabbits in control group were examined with dual‐source CT perfusion imaging .Perfusion pa‐rameters include arterial liver perfusion (ALP) ,portal venous perfusion (PVP) ,hepatic perfusion index (HPI) ,blood flow (BF) ,blood volume (BV) along with serum fibrosismarkers :hyaluronic (HA) ,laminin (LN) ,Procollagen type Ⅲ(PC Ⅲ) ,Ⅳ collagen (IV‐C) ,were achieved and compared with those in the different groups proved by pathology .All the perfusion parameters and

  6. Dual bolus intravenous contrast injection technique for multiregion paediatric body CT

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Karen E.; Mann, E.H.; Padfield, N.; Greco, L.; BenDavid, G. [The Hospital for Sick Children, Department of Diagnostic Imaging, Toronto (Canada); Alzahrani, A. [King Abdulaziz Medical City, PO Box 22490, Riyadh (Saudi Arabia)

    2015-04-01

    Optimal vascular and parenchymal enhancement for multi-region paediatric body computed tomography (CT) has many challenges. A variety of approaches are currently employed, associated with varying image quality and radiation dose implications. We present a dual bolus intravenous (DBI) contrast technique for single-acquisition imaging of the chest, abdomen and pelvis, with evaluation of multi-compartmental vascular enhancement. A DBI regime was designed for use with a programmable dual head pump injector. A larger initial bolus (two-thirds volume) is followed by a smaller bolus (one-third volume) before imaging the chest, abdomen and pelvis in a single acquisition, 45-65 seconds from the start of initial injection. Flow rates and second bolus timing were tailored to patient weight and contrast volume, using five weight categories. Multi-compartmental vascular opacification was graded and image quality was assessed in a cohort of 130 patients. The DBI technique resulted in concordant multi-compartmental (thoracic aortic, pulmonary arterial, abdominal aortic and portal venous) vascular enhancement. Early splenic parenchymal enhancement artefacts and alterations to renal enhancement were observed. We present a weight-stratified dual bolus intravenous contrast technique to improve image quality in paediatric multi-region body CT. (orig.)

  7. Dual energy CT at the synchrotron: A piglet model for neurovascular research

    Energy Technology Data Exchange (ETDEWEB)

    Schueltke, Elisabeth, E-mail: e.schultke@usask.ca [University of Saskatchewan, Saskatoon, SK (Canada); Kelly, Michael E. [University of Saskatchewan, Saskatoon, SK (Canada); Nemoz, Christian [European Synchrotron Radiation Facility (ESRF), 6 rue Horowitz, 38043 Grenoble (France); Fiedler, Stefan [European Molecular Biology Laboratory (EMBL), Nottkestrasse 85, 22603 Hamburg (Germany); Ogieglo, Lissa [University of Saskatchewan, Saskatoon, SK (Canada); Crawford, Paul [Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Herfordshire AL9 7TA (United Kingdom); Paterson, Jessica; Beavis, Cole [University of Saskatchewan, Saskatoon, SK (Canada); Esteve, Francois [CR INSERM U836-Team 6/ESRF, 6 rue Horowitz, 38043 Grenoble (France); Brochard, Thierry; Renier, Michel; Requardt, Herwig; Dallery, Dominique; Le Duc, Geraldine [European Synchrotron Radiation Facility (ESRF), 6 rue Horowitz, 38043 Grenoble (France); Meguro, Kotoo [University of Saskatchewan, Saskatoon, SK (Canada)

    2011-08-15

    Background: Although the quality of imaging techniques available for neurovascular angiography in the hospital environment has significantly improved over the last decades, the equipment used for clinical work is not always suited for neurovascular research in animal models. We have previously investigated the suitability of synchrotron-based K-edge digital subtraction angiography (KEDSA) after intravenous injection of iodinated contrast agent for neurovascular angiography in radiography mode in both rabbit and pig models. We now have used the KEDSA technique for the acquisition of three-dimensional images and dual energy CT. Materials and methods: All experiments were conducted at the biomedical beamline ID 17 of the European Synchrotron Radiation Facility (ESRF). A solid state germanium (Ge) detector was used for the acquisition of image pairs at 33.0 and 33.3 keV. Three-dimensional images were reconstructed from an image series containing 60 single images taken throughout a full rotation of 360{sup o}. CT images were reconstructed from two half-acquisitions with 720 projections each. Results: The small detector field of view was a limiting factor in our experiments. Nevertheless, we were able to show that dual energy CT using the KEDSA technique available at ID 17 is suitable for neurovascular research in animal models.

  8. 双源CT单能谱成像技术在腰椎峡部裂术后去除金属内固定伪影的应用%The application of monoenergetic technology of dual-source CT in removing the artifact of metal fixation after the operation of lumbar spondylolysis

    Institute of Scientific and Technical Information of China (English)

    毛锡金; 夏吉凯; 曹新山

    2014-01-01

    Objective To explore the clinical value of monoenergetic technology of dual-source CT in removing the artifact of me-tallic fixation after the operation of lumbar spondylolysis.Methods 24 cases of patients with metallic fixation after operation of lum-bar spondylolysis were scanned by dual-energy CT.To reconstruct the imaging using monoenergetic and 3D Inspace software,obtain 50,80,110,140,170 keV five groups of images and the multi-planar reconstruction*(MPR),volume vendering(VR),maximum intensity projection(MIP)imaging in different conditions.The five groups image and average weighted 120kev image are evaluate by two senior radiologist.The quality score of five groups of images and the average weighted images are analyzed statistically using Kruskal-Wallis test.The clinical value of images in the optimal condition are evaluated by two senior department of orthopedics phy-sicians.The results of two radiologists and department of orthopedics physician are examined by kappa test to evaluate consistency. Results In all patients after operation,the case of 110keV images above 3 points is 24,the case of 80keV images above 3 points is 14,the case of of 140keV images above 3 points is 13,the case of weighted average 120kev images above 3 points is 8.Images in 110keV have the best quality (F=98.523,P<0.01).MPR,VR,MIP images are reconstructed in 110keV.The ratio of image which are excellent and have high clinical value is 86.1%,especially the ratio of MPR image is 100%.Conclusion Monoenergetic technology of dual-source CT has a higher clinical value in removing the artifact of metallic fixation after the operation of lumbar spondylolysis.Under the condition of 110keV the quality of images are best,the reconstructed images using MPR Technology have the best clinical value.%目的:探索双源CT单能谱成像技术在腰椎峡部裂术后去除金属内固定伪影的临床应用价值。方法24例腰椎峡部裂内固定术后患者,采用双源CT双能量模式扫

  9. Coronary fly-through or virtual angioscopy using dual-source MDCT data.

    Science.gov (United States)

    van Ooijen, Peter M A; de Jonge, Gonda; Oudkerk, Matthijs

    2007-11-01

    Coronary fly-through or virtual angioscopy (VA) has been studied ever since its invention in 2000. However, application was limited because it requires an optimal computed tomography (CT) scan and time-consuming post-processing. Recent advances in post-processing software facilitate easy construction of VA, but until now image quality was insufficient in most patients. The introduction of dual-source multidetector CT (MDCT) could enable VA in all patients. Twenty patients were scanned using a dual-source MDCT (Definition, Siemens, Forchheim, Germany) using a standard coronary artery protocol. Post-processing was performed on an Aquarius Workstation (TeraRecon, San Mateo, Calif.). Length travelled per major branch was recorded in millimetres, together with the time required in minutes. VA could be performed in every patient for each of the major coronary arteries. The mean (range) length of the automated fly-through was 80 (32-107) mm for the left anterior descending (LAD), 75 (21-116) mm for the left circumflex artery (LCx), and 109 (21-190) mm for the right coronary artery (RCA). Calcifications and stenoses were visualised, as well as most side branches. The mean time required was 3 min for LAD, 2.5 min for LCx, and 2 min for the RCA. Dual-source MDCT allows for high quality visualisation of the coronary arteries in every patient because scanning with this machine is independent of the heart rate. This is clearly shown by the successful VA in all patients. Potential clinical value of VA should be determined in the near future.

  10. Radiation Optimized Dual-source Dual-energy Computed Tomography Pulmonary Angiography: Intra-individual and Inter-individual Comparison.

    Science.gov (United States)

    Li, Xie; Chen, Guo Zhong; Zhao, Yan E; Schoepf, U Joseph; Albrecht, Moritz H; Bickford, Matthew W; Gu, Hai Feng; Zhang, Long Jiang; Lu, Guang Ming

    2017-01-01

    This study aimed to intra-individually and inter-individually compare image quality, radiation dose, and diagnostic accuracy of dual-source dual-energy computed tomography pulmonary angiography (CTPA) protocols in patients with suspected pulmonary embolism (PE). Thirty-three patients with suspected PE underwent initial and follow-up dual-energy CTPA at 80/Sn140 kVp (group A) or 100/Sn140 kVp (group B), which were assigned based on tube voltages. Subjective and objective CTPA image quality and lung perfusion map image quality were evaluated. Diagnostic accuracies of CTPA and perfusion maps were assessed by two radiologists independently. Effective dose (ED) was calculated and compared. Mean computed tomography (CT) values of pulmonary arteries were higher in group A than group B (P = .006). There was no difference in signal-to-noise ratio and contrast-to-noise ratio between the two groups (both P > .05). Interobserver agreement for evaluating subjective image quality of CTPA and color-coded perfusion images was either good (κ = 0.784) or excellent (κ = 0.887). Perfusion defect scores and diagnostic accuracy of CTPA showed no difference between both groups (both P > .05). Effective dose of group A was reduced by 45.8% compared to group B (P energy CTPA with 80/Sn140 kVp allows for sufficient image quality and diagnostic accuracy for detecting PE while substantially reducing radiation dose. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  11. Dual-wavelength laser source for onboard atom interferometry.

    Science.gov (United States)

    Ménoret, V; Geiger, R; Stern, G; Zahzam, N; Battelier, B; Bresson, A; Landragin, A; Bouyer, P

    2011-11-01

    We present a compact and stable dual-wavelength laser source for onboard atom interferometry with two different atomic species. It is based on frequency-doubled telecom lasers locked on a femtosecond optical frequency comb. We take advantage of the maturity of fiber telecom technology to reduce the number of free-space optical components, which are intrinsically less stable, and to make the setup immune to vibrations and thermal fluctuations. The source provides the frequency agility and phase stability required for atom interferometry and can easily be adapted to other cold atom experiments. We have shown its robustness by achieving the first dual-species K-Rb magneto-optical trap in microgravity during parabolic flights.

  12. Dual-wavelength laser source for onboard atom interferometry

    CERN Document Server

    Ménoret, Vincent; Stern, Guillaume; Zahzam, Nassim; Battelier, Baptiste; Bresson, Alexandre; Landragin, Arnaud; Bouyer, Philippe

    2011-01-01

    We present a compact and stable dual-wavelength laser source for onboard atom interferometry with two different atomic species. It is based on frequency-doubled telecom lasers locked on a femtosecond optical frequency comb. We take advantage of the maturity of fiber telecom technology to reduce the number of free-space optical components which are intrinsically less stable, and to make the setup immune to vibrations and thermal fluctuations. The source provides the frequency agility and phase stability required for atom interferometry and can easily be adapted to other cold atom experiments. We have shown its robustness by achieving the first dual-species K-Rb magneto optical trap in microgravity during parabolic flights.

  13. Optimization of dual-energy CT acquisitions for proton therapy using projection-based decomposition.

    Science.gov (United States)

    Vilches-Freixas, Gloria; Létang, Jean Michel; Ducros, Nicolas; Rit, Simon

    2017-09-01

    Dual-energy computed tomography (DECT) has been presented as a valid alternative to single-energy CT to reduce the uncertainty of the conversion of patient CT numbers to proton stopping power ratio (SPR) of tissues relative to water. The aim of this work was to optimize DECT acquisition protocols from simulations of X-ray images for the treatment planning of proton therapy using a projection-based dual-energy decomposition algorithm. We have investigated the effect of various voltages and tin filtration combinations on the SPR map accuracy and precision, and the influence of the dose allocation between the low-energy (LE) and the high-energy (HE) acquisitions. For all spectra combinations, virtual CT projections of the Gammex phantom were simulated with a realistic energy-integrating detector response model. Two situations were simulated: an ideal case without noise (infinite dose) and a realistic situation with Poisson noise corresponding to a 20 mGy total central dose. To determine the optimal dose balance, the proportion of LE-dose with respect to the total dose was varied from 10% to 90% while keeping the central dose constant, for four dual-energy spectra. SPR images were derived using a two-step projection-based decomposition approach. The ranges of 70 MeV, 90 MeV, and 100 MeV proton beams onto the adult female (AF) reference computational phantom of the ICRP were analytically determined from the reconstructed SPR maps. The energy separation between the incident spectra had a strong impact on the SPR precision. Maximizing the incident energy gap reduced image noise. However, the energy gap was not a good metric to evaluate the accuracy of the SPR. In terms of SPR accuracy, a large variability of the optimal spectra was observed when studying each phantom material separately. The SPR accuracy was almost flat in the 30-70% LE-dose range, while the precision showed a minimum slightly shifted in favor of lower LE-dose. Photon noise in the SPR images (20 mGy dose

  14. Dual energy CT inspection of a carbon fibre reinforced plastic composite combined with metal components

    Directory of Open Access Journals (Sweden)

    Daniel Vavrik

    2016-11-01

    Full Text Available This work is focused on the inspection of carbon fibre reinforced plastic composites (CFRP combined with metal components. It is well known that the high absorption of metallic parts degrades the quality of radiographic measurements (contrast and causes typical metal artefacts in X-ray computed tomography (CT reconstruction. It will be shown that these problems can be successfully solved utilizing the dual energy CT method (DECT, which is typically used for the material decomposition of complex objects. In other words, DECT can help differentiate object components with a similar overall attenuation or visualise low attenuation components that are next to high attenuation ones. The application of DECT to analyse honeycomb sandwich panels and CFRP parts joined with metal fasteners will be presented in the article.

  15. Transient heterogeneous enhancement on dual-phase helical CT of liver

    Energy Technology Data Exchange (ETDEWEB)

    Ishibashi, Tadashi; Hama, Hikaru; Oikawa, Hideki; Yamada, Takayuki; Abe, Hiroyuki; Saitoh, Haruo; Sakamoto, Kiyohiko [Tohoku Univ., Sendai (Japan). School of Medicine; Satoh, Akihiro

    1996-08-01

    Transient heterogeneous enhancement was seen on the arterial phase of dual-phase helical CT of the liver. The shape of the enhancement was appeared wedged or patchy. These phenomena without liver tumor were observed in 23 (2.3%) of 1012 patients with suspected hepatobiliary disease. Plain CT showed no attenuation difference in the liver. Twenty-two of these 23 cases were diagnosed as scarred liver, A-P shunt caused by liver biopsy, acute cholecystitis, liver abscess, liver cirrhosis, or advanced pancreas head cancer. The diagnosis of one case was uncertain. These phenomena were thought to be caused by a regional direct increase in hepatic arterial flow due to arterial-portal (A-P) shunt, or hypervascular tumor; or a compensatory increase in hepatic arterial flow as a result of decreased portal venous flow caused by tumor invasion or severe liver cirrhosis. (author)

  16. Advanced dual-energy CT applications for the evaluation of the soft tissues of the neck.

    Science.gov (United States)

    Forghani, R; Mukherji, S K

    2017-05-02

    There are multiple emerging advanced computed tomography (CT) applications for the evaluation of the neck, many based on dual-energy CT (DECT). DECT is an advanced form of CT in which scan acquisition is performed at two different energies, enabling spectral tissue characterisation beyond what is possible with conventional single-energy CT and potentially providing a new horizon for quantitative analysis and tissue characterisation, particularly in oncological imaging. The purpose of this review is to familiarise the reader with DECT principles and review different clinical applications for the evaluation of the soft tissues of the neck. The article will begin with an overview of DECT scan acquisition, material characterisation, reconstructions, and basic considerations for implementation in the clinical setting. This will then be followed by a review of different clinical applications. The focus will be on oncological imaging, but artefact reduction and other miscellaneous applications will also be discussed. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  17. Edge-oriented dual-dictionary guided enrichment (EDGE) for MRI-CT image reconstruction.

    Science.gov (United States)

    Li, Liang; Wang, Bigong; Wang, Ge

    2016-01-01

    In this paper, we formulate the joint/simultaneous X-ray CT and MRI image reconstruction. In particular, a novel algorithm is proposed for MRI image reconstruction from highly under-sampled MRI data and CT images. It consists of two steps. First, a training dataset is generated from a series of well-registered MRI and CT images on the same patients. Then, an initial MRI image of a patient can be reconstructed via edge-oriented dual-dictionary guided enrichment (EDGE) based on the training dataset and a CT image of the patient. Second, an MRI image is reconstructed using the dictionary learning (DL) algorithm from highly under-sampled k-space data and the initial MRI image. Our algorithm can establish a one-to-one correspondence between the two imaging modalities, and obtain a good initial MRI estimation. Both noise-free and noisy simulation studies were performed to evaluate and validate the proposed algorithm. The results with different under-sampling factors show that the proposed algorithm performed significantly better than those reconstructed using the DL algorithm from MRI data alone.

  18. Pre- and postsurgical diagnostics with dual-source computed tomography in cardiac surgery; Einsatz der Dual-source-Computertomographie in der prae- und postoperativen kardiochirurgischen Diagnostik

    Energy Technology Data Exchange (ETDEWEB)

    Nikolaou, K.; Saam, T.; Rist, C.; Johnson, T.; Reiser, M.F.; Becker, C.R. [Klinikum Grosshadern der Ludwig-Maximilians-Universitaet Muenchen, Institut fuer Klinische Radiologie, Muenchen (Germany); Vogt, F.; Oberhoffer, M.; Reichart, B. [Ludwig-Maximilians-Universitaet Muenchen, Herzchirurgische Klinik und Poliklinik, Muenchen (Germany)

    2007-04-15

    The aim of this study was to evaluate the clinical potential of dual-source computed tomography (DSCT) in pre- and postsurgical diagnostics in the field of cardiac surgery. A total of 20 patients underwent DSCT of the heart. This CT system with two rotating X-ray tubes (Somatom Definition, Siemens Medical Solutions, Forchheim, Germany) achieves a temporal resolution of 83 ms and a spatial resolution of 0.4 x 0.4 x 0.4 mm. The patient cohort consisted of two subgroups. In a group of ten patients with known coronary artery disease (CAD), scheduled for bypass surgery (i.e., high pretest likelihood for having significant CAD), the results of DSCT coronary angiography (CTA) and invasive quantitative catheter angiography (QCA) were compared to assess the diagnostic accuracy of DSCT in the detection of significant coronary artery stenoses (>50%). In a second group of ten patients with previous aortic valve replacement (homografts), the valve opening area of the transplanted aortic valve graft was measured by DSCT and compared with echocardiography as a standard of reference to exclude postsurgical restenosis of the valve. Of 150 coronary artery segments depicted by CT, 144 (96%) were classified as ''assessable.'' A significant CAD was known in all patients, and altogether 43 significant stenoses were present according to the results of QCA. Blinded to these results, DSCTA reached a sensitivity and specificity of 95% (41/43) and 93% (103/111), yielding a positive and negative predictive value (PPV, NPV) of 79% (31/39) and 98% (103/105), respectively. In patients with aortic valve homografts, all DSCT datasets were considered as being of diagnostic image quality concerning valve depiction. The planimetric evaluation of the CT data as compared to results of echocardiography showed a significant correlation of the results (r=0.64, p=0.0467). A high-grade valve stenosis (opening area <1.0 cm{sup 2}) could be correctly excluded by DSCT in all patients. Dual-source

  19. First experience with single-source dual-energy computed tomography in six patients with acute arthralgia: a feasibility experiment using joint aspiration as a reference

    Energy Technology Data Exchange (ETDEWEB)

    Diekhoff, Torsten; Kiefer, Tobias; Hamm, Bernd; Hermann, Kay-Geert A. [Charite - Universitaetsmedizin Berlin Campus Mitte, Humboldt-Universitaet zu Berlin, Freie Universitaet Berlin, Department of Radiology, Berlin (Germany); Ziegeler, Katharina; Feist, Eugen [Charite - Universitaetsmedizin Berlin Campus Mitte, Humboldt-Universitaet zu Berlin, Freie Universitaet Berlin, Department of Rheumatology and Clinical Immunology, Berlin (Germany); Mews, Juergen [Toshiba Medical Systems Europe, BV, Zoetermeer (Netherlands)

    2015-11-15

    Dual-energy computed tomography (DECT) is an emerging imaging technique for examining patients with suspected gout. Single-source dual-energy CT (S-DECT) is a new way of obtaining DECT information on conventional CT scanners rather than using special dual-source CT systems. We tested the feasibility of S-DECT (320-row CT; Aquilion ONE, Toshiba Medical Systems, Otawara, Japan) in 6 patients (5 men, 1 woman; mean age 61.3, range 48 to 69 years) with acute arthralgia and suspected gout, and compared the S-DECT findings with the results of joint aspiration. Three patients had a diagnosis of gouty arthritis with negatively birefringent crystals in synovial fluid, in addition to gouty tophi in S-DECT. Three patients had no detectable crystals by polarization microscopy and no tophi on DECT. Their final diagnoses were rheumatoid arthritis, activated osteoarthritis, and septic arthritis in one case each. This initial experience suggests that S-DECT might be a valuable alternative to dual-source CT. Hence, more patients may benefit from its additional diagnostic abilities in the future. (orig.)

  20. Reliability of visual assessment of non-contrast CT, CT angiography source images and CT perfusion in patients with suspected ischemic stroke.

    Directory of Open Access Journals (Sweden)

    Tom van Seeters

    Full Text Available BACKGROUND AND PURPOSE: Good reliability of methods to assess the extent of ischemia in acute stroke is important for implementation in clinical practice, especially between observers with varying experience. Our aim was to determine inter- and intra-observer reliability of the 1/3 middle cerebral artery (MCA rule and the Alberta Stroke Program Early CT Score (ASPECTS for different CT modalities in patients suspected of acute ischemic stroke. METHODS: We prospectively included 105 patients with acute neurological deficit due to suspected acute ischemic stroke within 9 hours after symptom onset. All patients underwent non-contrast CT, CT perfusion and CT angiography on admission. All images were evaluated twice for presence of ischemia, ischemia with >1/3 MCA involvement, and ASPECTS. Four observers evaluated twenty scans twice for intra-observer agreement. We used kappa statistics and intraclass correlation coefficient to calculate agreement. RESULTS: Inter-observer agreement for the 1/3 MCA rule and ASPECTS was fair to good for non-contrast CT, poor to good for CT angiography source images, but excellent for all CT perfusion maps (cerebral blood volume, mean transit time, and predicted penumbra and infarct maps. Intra-observer agreement for the 1/3 MCA rule and ASPECTS was poor to good for non-contrast CT, fair to moderate for CT angiography source images, and good to excellent for all CT perfusion maps. CONCLUSION: Between observers with a different level of experience, agreement on the radiological diagnosis of cerebral ischemia is much better for CT perfusion than for non-contrast CT and CT angiography source images, and therefore CT perfusion is a very reliable addition to standard stroke imaging.

  1. 无症状高尿酸血症患者及痛风患者四肢关节尿酸盐结晶的双源CT对比分析%Analysis of urate crystal deposition us ing dual-source CT in asymptomatic hyperuricaemia and symptomatic gout patients

    Institute of Scientific and Technical Information of China (English)

    程留慧; 王道清; 张保朋; 王锁刚; 周舟; 温泽迎

    2015-01-01

    Objective Retrospectively analyze of urate crystal deposition using dual-source CT in asymptomatic hyperuricaemia and symptomatic gout patients.Methods Sixty patients with asymptomatic hyperuricemia (uric acid ≥540 μmol/L) and 48 patients with gout (without any change in the appearance of the limbs and obvious gout nodules) were selected.All patients underwent dual-energy CT imaging.The location number and size were analyzed using CT gout software.Results Eighteen patients with asymptomatic hyperuricemia with urate crystal deposition in limb joints (13 in foot and ankle, 7 in the hand and wrist, 2 in knee), the average size of crystal was (0.12±0.04) cm3.Forty-eight gout patients (28 cases of early gout and 20 cases of late gout and 20 gout cases) had urate crystal deposition (48 in foot and ankle, 39 in hand and wrist, 27 in knee), the average size of crystal was (1.7±0.7) cm3.The number and size of urate crystals deposited in the joints, tendons and ligaments was higher in patients with gout than asymptomatic hyperuricemia (x2=52.076, P<0.001;t=44.834, P<0.001).There was no difference between the early gout and late gout in the size of urate crystals (t=0.163, P>0.05).Conclusion Urate crystals can deposite in asymptomatic hyperuricemia.However, more and larger urate crystals appear in gout patients, there is no difference in size and number of urate crystals between the course duration of gout.%目的 利用双源CT(DSCT)双能成像技术对无症状高尿酸血症患者及痛风患者体内尿酸盐结晶沉积进行对比分析.方法 选择60例无症状高尿酸血症(尿酸值≥540 μmol/L)患者及48例经临床确诊且具有临床症状的痛风患者(四肢外观无任何改变和触摸不到明显痛风结节).对所有患者四肢关节进行DSCT双能成像检查,利用痛风分析软件对2组患者尿酸盐结晶沉积部位、数目及大小进行对比分析.统计学处理采用t检验、x2检验.结果 18例无症状高尿酸血症

  2. Dual time point 18FDG-PET/CT versus single time point 18FDG-PET/CT for the differential diagnosis of pulmonary nodules - A meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Li; Wang, Yinzhong [The First Clinical Medical School of Lanzhou Univ., Lanzhou, Gansu (China); Evidence-based Medicine Center, School of Basic Medical Sciences, Lanzhou Univ., Lanzhou, Gansu (China); Lei, Junqiang; Tian, Jinhui; Zhai, Yanan [The First Clinical Medical School of Lanzhou Univ., Lanzhou, Gansu (China); Evidence-based Medicine Center, School of Basic Medical Sciences, Lanzhou Univ., Lanzhou, Gansu (China); The First Hospital of Lanzhou Univ., Lanzhou, Gansu (China)

    2013-09-15

    Background: Lung cancer is one of the most common cancer types in the world. An accurate diagnosis of lung cancer is crucial for early treatment and management. Purpose: To perform a comprehensive meta-analysis to evaluate the diagnostic performance of dual time point 18F-fluorodexyglucose position emission tomography/computed tomography (FDG-PET/CT) and single time point 18FDG-PET/CT in the diagnosis of pulmonary nodules. Material and Methods: PubMed (1966-2011.11), EMBASE (1974-2011.11), Web of Science (1972-2011.11), Cochrane Library (-2011.11), and four Chinese databases; CBM (1978-2011.11), CNKI (1994-2011.11), VIP (1989-2011.11), and Wanfang Database (1994-2011.11) were searched. Summary sensitivity, summary specificity, summary diagnostic odds ratios (DOR), and summary positive likelihood ratios (LR+) and negative likelihood ratios (LR-) were obtained using Meta-Disc software. Summary receiver-operating characteristic (SROC) curves were used to evaluate the diagnostic performance of dual time point 18FDG-PET/CT and single time point 18FDG-PET/CT. Results: The inclusion criteria were fulfilled by eight articles, with a total of 415 patients and 430 pulmonary nodules. Compared with the gold standard (pathology or clinical follow-up), the summary sensitivity of dual time point 18FDG-PET/CT was 79% (95%CI, 74.0 - 84.0%), and its summary specificity was 73% (95%CI, 65.0-79.0%); the summary LR+ was 2.61 (95%CI, 1.96-3.47), and the summary LR- was 0.29 (95%CI, 0.21 - 0.41); the summary DOR was 10.25 (95%CI, 5.79 - 18.14), and the area under the SROC curve (AUC) was 0.8244. The summary sensitivity for single time point 18FDG-PET/CT was 77% (95%CI, 71.9 - 82.3%), and its summary specificity was 59% (95%CI, 50.6 - 66.2%); the summary LR+ was 1.97 (95%CI, 1.32 - 2.93), and the summary LR- was 0.37 (95%CI, 0.29 - 0.49); the summary DOR was 6.39 (95%CI, 3.39 - 12.05), and the AUC was 0.8220. Conclusion: The results indicate that dual time point 18FDG-PET/CT and single

  3. Quantitative assessment of scatter correction techniques incorporated in next generation dual-source computed tomography

    Science.gov (United States)

    Mobberley, Sean David

    Accurate, cross-scanner assessment of in-vivo air density used to quantitatively assess amount and distribution of emphysema in COPD subjects has remained elusive. Hounsfield units (HU) within tracheal air can be considerably more positive than -1000 HU. With the advent of new dual-source scanners which employ dedicated scatter correction techniques, it is of interest to evaluate how the quantitative measures of lung density compare between dual-source and single-source scan modes. This study has sought to characterize in-vivo and phantom-based air metrics using dual-energy computed tomography technology where the nature of the technology has required adjustments to scatter correction. Anesthetized ovine (N=6), swine (N=13: more human-like rib cage shape), lung phantom and a thoracic phantom were studied using a dual-source MDCT scanner (Siemens Definition Flash. Multiple dual-source dual-energy (DSDE) and single-source (SS) scans taken at different energy levels and scan settings were acquired for direct quantitative comparison. Density histograms were evaluated for the lung, tracheal, water and blood segments. Image data were obtained at 80, 100, 120, and 140 kVp in the SS mode (B35f kernel) and at 80, 100, 140, and 140-Sn (tin filtered) kVp in the DSDE mode (B35f and D30f kernels), in addition to variations in dose, rotation time, and pitch. To minimize the effect of cross-scatter, the phantom scans in the DSDE mode was obtained by reducing the tube current of one of the tubes to its minimum (near zero) value. When using image data obtained in the DSDE mode, the median HU values in the tracheal regions of all animals and the phantom were consistently closer to -1000 HU regardless of reconstruction kernel (chapters 3 and 4). Similarly, HU values of water and blood were consistently closer to their nominal values of 0 HU and 55 HU respectively. When using image data obtained in the SS mode the air CT numbers demonstrated a consistent positive shift of up to 35 HU

  4. Dual-time FDG-PET/CT in patients with potential breast cancer recurrence: Head-to-head comparison with CT and bone scintigraphy

    DEFF Research Database (Denmark)

    Baun, Christina; Falch Braas, Kirsten; Gerke, Oke

    Dual-time FDG-PET/CT in patients with potential breast cancer recurrence: Head-to-head comparison with CT and bone scintigraphy  Kirsten Falch, Christina Baun, Oke Gerke, , Ziba A. Farahani, Poul F. Høilund-Carlsen, Lisbet B. Larsen*, Marianne Ewertz**, Katrine Søe*** and Malene G. Hildebrandt...... Departments of Nuclear Medicine, *Radiology, **Oncolocy, and ***Surgery, Odense University Hospital, Odense, Denmark Purpose: Breast cancer (BC) is the most common type of cancer among women in Denmark and about 1/3 of the affected women experience recurrence. The prognosis is good if loco regional recurrence...... FDG PET/CT, routine bone scintigraphy and CT of the chest and upper abdomen within 2 weeks. Patients with other malignancies, pregnant or lactating women, patients younger than 18 years and patients with confirmed metastatic disease were not eligible FDG PET/CT. All patients fasted for a minimum...

  5. WE-A-BRF-01: Dual-Energy CT Imaging in Diagnostic Imaging and Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Molloi, S [University of California, Irvine, CA (United States); Li, B [Boston University Medical Center, Boston, MA (United States); Yin, F [Duke University Medical Center, Durham, NC (United States); Chen, H [New York Presbyterian Hospital, New York, NY (United States)

    2014-06-15

    The quantification accuracy of dual-energy imaging is influenced by the fundamentals of x-ray physics, system geometry, data acquisition hardware/protocol, system calibration, and image processing technique. This symposium will provide updates on the following advanced application areas: Mammography. Volumetric breast density techniques based on standard mammograms require estimation of breast thickness, which is difficult to accurately measure. By comparison, calculation of breast density using dual energy mammography does not require measurement of breast thickness. Dual energy mammography has been implemented using both energy integrating flat panel detectors in conjunction with beam energy switching and energy resolved photon counting detectors. These techniques have been optimized using simulation studies and validated using physical phantoms and postmortem breasts. Chemical decomposition was used as the gold standard for volumetric breast density measurement in postmortem breasts. Breast density measurements have also been compared with results from four-category BI-RADS density rankings, standard image thresholding and Fuzzy k-mean clustering techniques. These studies indicate that dual energy mammography can be used to accurately measure volumetric breast density. Cardiovascular CT. The predicative accuracy of risk models for recurrent stroke and cardiac arrest depends heavily on accurate differentiation of thrombus or calcium from iodine in left atrial appendage or coronary arteries. The amount of energy separation is constrained by image noise; therefore, optimal kVp, beam filtration, and balanced flux are essential for the quantification accuracy of iodine and calcium. The basis materials are combined linearly to generate monochromatic energy images, where CT# accuracy and CNR are energy dependent. With optimal monochromatic energy, the mean iodine concentration for the thrombus, circulatory stasis, and control groups are significantly different. Risk

  6. Thoracic applications of dual energy.

    Science.gov (United States)

    Remy-Jardin, Martine; Faivre, Jean-Baptiste; Pontana, Francois; Hachulla, Anne-Lise; Tacelli, Nunzia; Santangelo, Teresa; Remy, Jacques

    2010-01-01

    Recent technological advances in multidetector computed tomography (CT) have led to the introduction of dual-source CT, which allows acquisition of CT data at the same energy or at 2 distinct tube voltage settings during a single acquisition. The advantage of the former is improvement of temporal resolution, whereas the latter offers new options for CT imaging, allowing tissue characterization and functional analysis with morphologic evaluation. The most investigated application has been iodine mapping at pulmonary CT angiography. The material decomposition achievable opens up new options for recognizing substances poorly characterized by single-energy CT. Although it is too early to draw definitive conclusions on dual-energy CT applications, this article reviews the results already reported with the first generation of dual-source CT systems.

  7. Dual-energy CT in the follow-up after endovascular abdominal aortic aneurysm repair; Dual-Energy CT zur postoperativen Langzeitkontrolle nach endovaskulaer therapierten abdominellen Aortenaneurysmen

    Energy Technology Data Exchange (ETDEWEB)

    Braegelmann, A.; Heindel, W.; Seifarth, H. [Universitaetsklinikum Muenster (Germany). Inst. fuer Klinische Radiologie; Bunck, A.; Maintz, D. [Universitaetsklinikum Muenster (Germany). Inst. fuer Klinische Radiologie; Universitaetsklinikum Koeln (Germany). Inst. und Poliklinik fuer Radiologische Diagnostik; Donas, K.; Kasprzak, B. [Universitaetsklinikum Muenster (Germany). Klinik fuer Vaskulaere und Endovaskulaere Chirurgie

    2013-04-15

    This study investigates the dual-energy procedure for postoperative CT follow-up scans after endovascularly treated abdominal aortic aneurysms. The procedure is analyzed with respect to its sensitivity and specificity as well as the associated radiation exposure. 51 examinations were carried out on 47 patients between February 2009 and March 2010. For each patient, a non-enhanced, an arterial and a venous scan were conducted, the latter two using the dual-energy technology. Virtual images for the non-enhanced phase were reconstructed from the data taken in the venous phase. Protocol A, the reference standard, consisted of non-enhanced images and images of the arterial and venous phase. In protocol B, standard non-enhanced images were replaced by the reconstructed virtual non-enhanced images. Protocol C consisted only of virtual non-enhanced and 80 kV images taken during the venous phase. All data was anonymized and evaluated by two independent radiologists. For protocol C, sensitivity, specificity, negative and positive predictive values were computed. The effective radiation dosage was determined for each scan. All endoleaks identified in protocol A were found using protocols B and C. For protocol C, the sensitivity and negative predictive value were 100 %, the specificity was 94.1 %, and the positive predictive value was 89.5 %. Compared to protocol A, protocol C reduces the radiation exposure by 62.45 %. A scan protocol consisting of virtual non-enhanced images as well as 80 kV images taken during the venous phase was found to be a reliable alternative method for diagnosing endoleaks, while reducing the radiation exposure by 62.45 %. (orig.)

  8. Dual-phase dual-energy CT in patients with lung cancer: assessment of the additional value of iodine quantification in lymph node therapy response

    Energy Technology Data Exchange (ETDEWEB)

    Baxa, Jan; Vondrakova, Alena; Matouskova, Tana; Ferda, Jiri [Charles University Teaching Hospital Plzen, Department of Imaging Methods, Plzen (Czech Republic); Ruzickova, Olga [Charles University Teaching Hospital Plzen, Department of Pulmonary Diseases, Plzen (Czech Republic); Schmidt, Bernhard; Flohr, Thomas; Sedlmair, Martin [Siemens Healthcare, CT Physics and Applications Development, Forchheim (Germany)

    2014-08-15

    To investigate the potential contribution of iodine uptake calculation from dual-phase dual-energy CT (DE-CT) for lymph node staging and therapy response monitoring in lung cancer patients. Retrospective analysis of 27 patients with non-small cell lung carcinoma (NSCLC), who underwent dual-phase DE-CT before and after chemotherapy, was performed. Iodine uptake (mg/mL) and total iodine uptake (mg) were calculated using prototype software in the early (arterial) and late (venous) post-contrast circulatory phase in 110 mediastinal lymph nodes. The arterial enhancement fraction (AEF) was calculated and compared with lymph node size and response to chemotherapy. A significant difference of AEF was observed between enlarged (90.4 %; 32.3-238.5 %) and non-enlarged (72.7 %; -37.5-237.5 %) lymph nodes (p = 0.044) before treatment onset. A significantly different change of AEF in responding (decrease of 26.3 %; p = 0.022) and non-responding (increase of 43.0 %; p = 0.031) lymph nodes was demonstrated. A higher value of AEF before treatment was observed in lymph nodes with subsequent favourable response (88.6 % vs. 77.7 %; p = 0.122), but this difference did not reach statistical significance. The dual-phase DE-CT examination with quantification of ratio of early and late post-contrast iodine uptake is a feasible and promising method for the functional evaluation of mediastinal lymph nodes including therapy response assessment. (orig.)

  9. Preliminary study on ultra low tube voltage (70kV)sequential scan with low-volume contrast media protocol for dual-source CT coronary angiography%70 kV超低管电压低对比剂用量冠状动脉CTA研究

    Institute of Scientific and Technical Information of China (English)

    曹剑; 王少华; 张龙江; 卢光明; 金征宇; 易妍; 王怡宁; 林路; 王明; 孔令燕; 薛华丹; 宋兰; 王志伟

    2014-01-01

    Objective:To investigate the application of ultra low tube voltage (70kV)for coronary artery CT angiog-raphy (CCTA)with low-volume contrast media and low inj ection rate on dual-source CT (DSCT)equipment with integrat-ed circuit (IC)detector.Methods:Fifty patients with body mass index (BMI)not more than 25kg/m2 were scanned with a prospectively ECG-triggering sequential CCTA protocol on DSCT.All patients were randomly divided into two groups:the injection rate and volume of contrast in Group A was 4.0ml/s and 32mL (350mg I/mL);those in Group B were 4.0mL/s and 50mL (350mg I/mL),respectively.Tube voltage of both groups was 70kV.The raw data were reconstructed with sino-gram affirmed iterative reconstruction (SAFIRE)technique.The differences of age,BMI,heart rate,background noise,sig-nal-to-noise ratio (SNR)and radiation dose between the two Groups were compared.Besides,the CT value and CNR of the aortic root and each segment of coronary arteries were compared.And Image quality (1~4,excellent to non-assessable)be-tween the two Groups was compared segment-based.Results:There were no significant differences in age,BMI,heart rate, background noise,SNR or radiation dose between the two Groups (all P>0.05),and the mean ED was about 0.90mSv.The CT value of the distal segment of each coronary arteries in Group B was higher than Group A,while there were no signifi-cant differences in the proximal and median segments between the two groups.However,the CNR of each segment of coro-nary arteries in Group B were higher than Group A (all P<0.01).Mean segment-based image quality scores showed no sig-nificant difference between the two Groups reconstructed with SAFIRE (Group A,1.16±0.18,Group B,1.18±0.18;P=0.75).The percentage of assessable segments in each Group were more than 98%.Conclusion:For patients with normal BMI,the use of tube voltage as 70kV with SAFIRE technique in DSCT equipped IC detector is feasible.And both the con-trast injection rate and volume can be much lower

  10. Feasibility analysis of diagnosis of ligament injury in the craniocervical junction with dual source CT%CT双能量技术在颅颈交界区韧带损伤诊断中的应用可行性分析

    Institute of Scientific and Technical Information of China (English)

    张武; 陈晶; 陈建强; 战跃福; 王雄; 杨光; 梁其洲

    2016-01-01

    Craniocervical junction is the key transitional part from head to neck, which has complex structure and special functions. Craniocervical ligament plays an important role in maintaining the stability, normal activities, and flexion and extension of the head and neck. The ligaments injuries have great harm to the health of the body, including at-lantoaxial dislocation, injury of medulla oblongata resulting paralysis and even death. Craniocervical junction has lots of ligaments, which were distributed deeply and were overlapped with each other. The diagnosis of ligament injury in cra-niocervical junction is difficult, which attract great attention from clinical and imaging researchers. This review aims at providing a reference for clinical diagnosis, treatment and prognosis of ligament injury in craniocervical junction by ana-lyzing the feasibility of diagnosis of ligament injury with dual source CT.%颅颈交界区是头颅向颈椎过渡的关键部位,该区域结构复杂,功能特殊。颅颈交界区韧带在维持颅颈部的稳定和正常旋转、屈伸运动中扮演着重要角色。颅颈交界区韧带损伤,轻则引起寰枕枢关节脱位,重则损伤延髓、颈髓引起瘫痪甚至危及生命。颅颈交界区韧带众多,位置深,相互重叠,其损伤诊断困难,成为临床和影像研究的热点和难点。本文通过对CT双能量技术在韧带损伤诊断中的应用可行性进行分析、综述,为颅颈交界区韧带损伤的临床诊断、治疗及预后评估提供技术支持和参考依据。

  11. Urinary stone detection and characterisation with dual-energy CT urography after furosemide intravenous injection: preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Botsikas, Diomidis; Hansen, Catrina; Stefanelli, Salvatore; Becker, Christoph D.; Montet, Xavier [Geneva University Hospital, Radiology Department, Geneva (Switzerland)

    2014-03-15

    To investigate the added advantage of IV furosemide injection and the subsequent urine dilution in the detection of urinary calculi in the excretory phase of dual-source dual-energy (DE) computed tomography (CT) urography, and to investigate the feasibility of characterising the calculi through diluted urine. Twenty-three urinary calculi were detected in 116 patients who underwent DECT urography for macroscopic haematuria with a split bolus two- or three-acquisition protocol, including a true unenhanced series and at least a mixed nephrographic excretory phase. Virtual unenhanced images were reconstructed from contrast-enhanced DE data. Calculi were recorded on all series and characterised based on their X-ray absorption characteristics at 100 kVp and 140 kVp in both true unenhanced and nephrographic excretory phase series. All calculi with a diameter more than 2 mm were detected in the virtual unenhanced phase and in the nephrographic excretory phase. Thirteen of these calculi could be characterised in the true unenhanced phase and in the mixed nephrographic excretory phase. The results were strictly identical for both phases, six of them being recognised as non-uric acid calculi and seven as uric acid calculi. Mixed nephrographic excretory phase DECT after furosemide administration allows both detection and characterisation of clinically significant calculi, through the diluted urine. (orig.)

  12. A Method to Improve Electron Density Measurement of Cone-Beam CT Using Dual Energy Technique

    Directory of Open Access Journals (Sweden)

    Kuo Men

    2015-01-01

    Full Text Available Purpose. To develop a dual energy imaging method to improve the accuracy of electron density measurement with a cone-beam CT (CBCT device. Materials and Methods. The imaging system is the XVI CBCT system on Elekta Synergy linac. Projection data were acquired with the high and low energy X-ray, respectively, to set up a basis material decomposition model. Virtual phantom simulation and phantoms experiments were carried out for quantitative evaluation of the method. Phantoms were also scanned twice with the high and low energy X-ray, respectively. The data were decomposed into projections of the two basis material coefficients according to the model set up earlier. The two sets of decomposed projections were used to reconstruct CBCT images of the basis material coefficients. Then, the images of electron densities were calculated with these CBCT images. Results. The difference between the calculated and theoretical values was within 2% and the correlation coefficient of them was about 1.0. The dual energy imaging method obtained more accurate electron density values and reduced the beam hardening artifacts obviously. Conclusion. A novel dual energy CBCT imaging method to calculate the electron densities was developed. It can acquire more accurate values and provide a platform potentially for dose calculation.

  13. Comparison of Multislice Spiral CT Dual Phase and Somatosatatin Receptor Scintigraphy in the Diagnosis of Pancreas Neuroendocrine Tumors.

    Science.gov (United States)

    2016-06-10

    Objective To compare the sensitivity of multislice spiral CT dual phase and somatosatatin receptor scintigraphy (SRS) in the diagnosis of pancreas nuroendocrine tumors (pNET). Methods Totally 28 patients with pathologically confirmed pNET recieved both CT dual phase contrast and SRS and the results were compared. Results Of these 28 pNET patients,26 (92.8%) were accurately diagnosed by CT dual-phase scan and 20 (71.4%) by SRS (P=0.031).In the functioning pNET cases,the diagnosis sensitivity of CT dual phase scan and SRS was 94.1% (16/17)and 58.8% (10/17)(P=0.218). In the non-functioning pNET cases,the sensitivity was 90.9% (10/11) and 90.9% (10/11) (P=0.740).Diagnostic sensitivity of CT dual phase scan and SRS for pNET without metastasis was 90.4% (19/21) and 57.1% (12/21) (P=0.125).The sensitivity for pNET with metastasis was 100%(7/7)and 100% (7/7). Corresponding to the pathological grading,the diagnostic sensitivity of CT dual phase scanning and SRS was 84.6% (11/13) and 53.8% (7/13) for G1,100% (12/12) and 83.3% (10/12) for G2,and 100% (3/3) and 100% (3/3) for G3. The diagnostic sensitivity of CT dual phase scan and SRS for pNET with diameter less than or equal to 2.0 cm was 94.7% (18/19) and 52.6% (10/19) (P=0.008). For pNET with diameter more than 2.0 cm,the sensitivity was 92.8% (13/14) and 100% (14/14). Conclusions Compared with SRS,dual phase CT scan is more sensitive in diagnosing pNET,especially for those in lower pathological stages. For lesions sized less than or equal to 2.0 cm,SRS should be combined with other imaging examinations to minimize false negative results.

  14. Pulmonary embolism detection using localized vessel-based features in dual energy CT

    Science.gov (United States)

    Dicente Cid, Yashin; Depeursinge, Adrien; Foncubierta Rodríguez, Antonio; Platon, Alexandra; Poletti, Pierre-Alexandre; Müller, Henning

    2015-03-01

    Pulmonary embolism (PE) affects up to 600,000 patients and contributes to at least 100,000 deaths every year in the United States alone. Diagnosis of PE can be difficult as most symptoms are unspecific and early diagnosis is essential for successful treatment. Computed Tomography (CT) images can show morphological anomalies that suggest the existence of PE. Various image-based procedures have been proposed for improving computer-aided diagnosis of PE. We propose a novel method for detecting PE based on localized vessel-based features computed in Dual Energy CT (DECT) images. DECT provides 4D data indexed by the three spatial coordinates and the energy level. The proposed features encode the variation of the Hounsfield Units across the different levels and the CT attenuation related to the amount of iodine contrast in each vessel. A local classification of the vessels is obtained through the classification of these features. Moreover, the localization of the vessel in the lung provides better comparison between patients. Results show that the simple features designed are able to classify pulmonary embolism patients with an AUC (area under the receiver operating curve) of 0.71 on a lobe basis. Prior segmentation of the lung lobes is not necessary because an automatic atlas-based segmentation obtains similar AUC levels (0.65) for the same dataset. The automatic atlas reaches 0.80 AUC in a larger dataset with more control cases.

  15. Ventilation imaging of the paranasal sinuses using xenon-enhanced dynamic single-energy CT and dual-energy CT: a feasibility study in a nasal cast.

    Science.gov (United States)

    Thieme, Sven F; Möller, Winfried; Becker, Sven; Schuschnig, Uwe; Eickelberg, Oliver; Helck, Andreas D; Reiser, Maximilian F; Johnson, Thorsten R C

    2012-10-01

    To show the feasibility of dual-energy CT (DECT) and dynamic CT for ventilation imaging of the paranasal sinuses in a nasal cast. In a first trial, xenon gas was administered to a nasal cast with a laminar flow of 7 L/min. Dynamic CT acquisitions of the nasal cavity and the sinuses were performed. This procedure was repeated with pulsating xenon flow. Local xenon concentrations in the different compartments of the model were determined on the basis of the enhancement levels. In a second trial, DECT measurements were performed both during laminar and pulsating xenon administration and the xenon concentrations were quantified directly. Neither with dynamic CT nor DECT could xenon-related enhancement be detected in the sinuses during laminar airflow. Using pulsating flow, dynamic imaging showed a xenon wash-in and wash-out in the sinuses that followed a mono-exponential function with time constants of a few seconds. Accordingly, DECT revealed xenon enhancement in the sinuses only after pulsating xenon administration. The feasibility of xenon-enhanced DECT for ventilation imaging was proven in a nasal cast. The superiority of pulsating gas flow for the administration of gas or aerosolised drugs to the paranasal sinuses was demonstrated. • Ventilation of the paranasal sinuses is poorly understood. • Dual-energy CT ventilation imaging has been explored using phantom simulation. • Xenon can be seen in the paranasal sinuses using pulsating xenon flow. • Dual-energy CT uses a lower radiation dose compared with dynamic ventilation CT.

  16. Diagnostic accuracy of dual energy CT angiography in patients with diabetes mellitus; Diagnostische Genauigkeit der Dual-energy-CT-Angiographie bei Patienten mit Diabetes mellitus

    Energy Technology Data Exchange (ETDEWEB)

    Schabel, C.; Bongers, M.N.; Syha, R. [Klinikum der Eberhard-Karls-Universitaet, Abteilung fuer Diagnostische und Interventionelle Radiologie, Tuebingen (Germany); Klinikum der Eberhard-Karls-Universitaet, Sektion fuer Experimentelle Radiologie der Abteilung fuer Diagnostische und Interventionelle Radiologie, Tuebingen (Germany); Ketelsen, D.; Homann, G.; Notohamiprodjo, M.; Nikolaou, K.; Bamberg, F. [Klinikum der Eberhard-Karls-Universitaet, Abteilung fuer Diagnostische und Interventionelle Radiologie, Tuebingen (Germany); Thomas, C. [Universitaetsklinikum Duesseldorf, Abteilung fuer Diagnostische und Interventionelle Radiologie, Duesseldorf (Germany)

    2015-04-01

    Peripheral arterial disease (PAD) represents a major and highly prevalent complication in patients with diabetes mellitus. The diagnostic, non-invasive work-up by computed tomography angiography (CTA) is limited in the presence of extensive calcification. The aim of the study was to determine the diagnostic accuracy of dual energy CTA (DE-CTA) for the detection and characterization of PAD in patients with diabetes mellitus. In this study 30 diabetic patients with suspected or known PAD were retrospectively included in the analysis. All subjects underwent DE-CTA (Somatom Definition Flash, Siemens Healthcare, Erlangen, Germany) prior to invasive angiography, which served as the reference standard. Blinded analysis included assessment of the presence and degree of peripheral stenosis on curved multiplanar reformatting (MPR) and maximum intensity projections (MIP). Conventional measures of diagnostic accuracy were derived. Among the 30 subjects included in the analysis (83 % male, mean age 70.0 ± 10.5 years, 83 % diabetes type 2), the prevalence of critical stenosis in 331 evaluated vessel segments was high (30 %). Dual energy CT identified critical stenoses with a high sensitivity and good specificity using curved MPR (100 % and 93.1 %, respectively) and MIP images (99 % and 91.8 %, respectively). In stratified analysis, the diagnostic accuracy was higher for stenosis pertaining to the pelvic and thigh vessels as compared with the lower extremities (curved MPR accuracy 97.1 % vs. 99.2 vs. 90.9 %; respectively, p < 0.001). The use of DE-CTA allows reliable detection and characterization of peripheral arterial stenosis in patients with diabetes mellitus with higher accuracy in vessels in the pelvic and thigh regions compared with the vessels in the lower legs. (orig.) [German] Die periphere arterielle Verschlusskrankheit (PAVK) ist eine wesentliche Komplikation des Diabetes mellitus und stellt aufgrund ausgepraegter Gefaessverkalkungen eine diagnostische

  17. Overview of multisource CT systems and methods

    Science.gov (United States)

    Zhao, Jun; Lu, Yang; Zhuang, Tiange; Wang, Ge

    2010-09-01

    Multiple-source cone-beam scanning is a promising mode for dynamic volumetric CT/micro-CT. The first dynamic CT system is the Dynamic Spatial Reconstructor (DSR) built in 1979. The pursuance for higher temporal resolution has largely driven the development of CT technology, and recently led to the emergence of Siemens dual-source CT scanner. Given the impact and limitation of dual-source cardiac CT, triple-source cone-beam CT seems a natural extension for future cardiac CT. Our work shows that trinity (triple-source architecture) is superior to duality (dual-source architecture) for helical cone-beam CT in terms of exact reconstruction. In particular, a triple-source helical scan allows a perfect mosaic of longitudinally truncated cone-beam data to satisfy the Orlov condition and yields better noise performance than the dual-source counterpart. In the (2N+1)-source helical CT case, the more sources, the higher temporal resolution. In the N-source saddle CT case, a triple-source scan offers the best temporal resolution for continuous dynamic exact reconstruction of a central volume. The recently developed multi-source cone-beam algorithms include an exact backprojection-filtration (BPF) approach and a "slow" exact filtered-backprojection (FBP) algorithm for (2N+1)-source helical CT, two fast quasi-exact FBP algorithms for triple-source helical CT, as well as a fast exact FBP algorithm for triple-source saddle CT. Some latest ideas will be also discussed, such as multi-source interior tomography and multi-beam field-emission x-ray CT.

  18. 基于同步辐射光源的双能CT成像方法%Dual-energy CT imaging method using synchrotron radiation

    Institute of Scientific and Technical Information of China (English)

    郝佳; 张丽; 邢宇翔; 康克军

    2011-01-01

    The distribution of electron density can be obtained by dual-energy imaging technology with high precision,which is important for medical diagnosis and treatment planning in the radiotherapy.A dual-energy CT imaging method was developed using synchrotron radiation to improve the reconstruction,with the interference light post-processing algorithm analyzed for reconstruction.Numerical simulations with different materials were implemented using the post-processing reconstruction method to show that the electron density and effective atomic number can be obtained with high precision,with much less error than that of conventional dual-energy CT system using Bremsstrahlung radiation.The results also show that dual-energy X-ray CT using synchrotron radiation has the potential to be an important tool for quantitative measurement in biological research.China has developed a third-generation synchrotron radiation light source in Shanghai,which provides an excellent scientific platform for the further research of dual-energy CT imaging.%双能X射线CT成像技术可以精确地获得被扫描物体中的电子密度分布,对于医疗诊断和癌症放射治疗具有重要的参考价值。为了提高双能CT重建精度,该文提出了一种基于同步辐射光源的双能CT成像方法,并对相干光的后处理重建算法进行了研究。同步辐射光源具有一系列的优势。使用不同物质进行双能CT成像数值模拟可以发现:采用同步辐射光源进行双能CT重建,可以更加精确地获取被扫描物质的等效原子序数及电子密度,误差远小于使用X光机的传统双能CT系统。结果表明,基于同步辐射光源的双能CT成像技术将成为生物医学中定量研究的重要手段。目

  19. Universal and robust electron-density assessment using dual-energy CT

    CERN Document Server

    Möhler, Christian; Richter, Christian; Greilich, Steffen

    2016-01-01

    Dual-energy computed tomography (DECT) can be used to acquire an electron-density and an effective-atomic-number image of the scanned object. We show that a simple one-parametric formula for the electron density follows from a basic assumption on the functional form of the cross section. This assumption is valid in the energy range relevant to a CT scanner and in the atomic number range relevant to human tissue. We propose a robust calibration for the electron-density equation, which is easily applicable using standard equipment, and provide parameters for two clinical DECT scanners. For the application in proton and ion radiation therapy, we suggest to use the relative cross section instead of the effective atomic number, as it enables a proper treatment of tissue mixtures, while providing the same contrast for diagnostic or delineation purposes.

  20. Whole-body adipose tissue analysis: comparison of MRI, CT and dual energy X-ray absorptiometry

    DEFF Research Database (Denmark)

    Kullberg, J; Brandberg, J; Angelhed, J-E

    2009-01-01

    The aim of this study was to validate a recently proposed MRI-based T(1)-mapping method for analysis of whole-body adipose tissue (AT) using an established CT protocol as reference and to include results from dual energy X-ray absorptiometry (DEXA). 10 subjects, drawn from the Swedish Obese...

  1. Acute gastrointestinal bleeding: detection of source and etiology with multi-detector-row CT

    Energy Technology Data Exchange (ETDEWEB)

    Scheffel, Hans; Pfammatter, Thomas; Marincek, Borut; Alkadhi, Hatem [University Hospital Zurich, Institute of Diagnostic Radiology, Zurich (Switzerland); Wildi, Stefan [University Hospital Zurich, Department of Visceral and Transplant Surgery, Zurich (Switzerland); Bauerfeind, Peter [University Hospital Zurich, Division of Gastroenterology, Zurich (Switzerland)

    2007-06-15

    This study was conducted to determine the ability of multi-detector-row computed tomography (CT) to identify the source and etiology of acute gastrointestinal bleeding. Eighteen patients with acute upper (n = 10) and lower (n = 8) gastrointestinal bleeding underwent 4-detector-row CT (n = 6), 16-detector-row CT (n = 11), and 64-slice CT (n = 1) with an arterial and portal venous phase of contrast enhancement. Unenhanced scans were performed in nine patients. CT scans were reviewed to determine conspicuity of bleeding source, underlying etiology, and for potential causes of false-negative prospective interpretations. Bleeding sources were prospectively identified with CT in 15 (83%) patients, and three (17%) bleeding sources were visualized in retrospect, allowing the characterization of all sources of bleeding with CT. Contrast extravasation was demonstrated with CT in all 11 patients with severe bleeding, but only in 1 of 7 patients with mild bleeding. The etiology could not be identified on unenhanced CT scans in any patient, whereas arterial-phase and portal venous-phase CT depicted etiology in 15 (83%) patients. Underlying etiology was correctly identified in all eight patients with mild GI bleeding. Multi-detector-row CT enables the identification of bleeding source and precise etiology in patients with acute gastrointestinal bleeding. (orig.)

  2. Acute gastrointestinal bleeding: detection of source and etiology with multi-detector-row CT.

    Science.gov (United States)

    Scheffel, Hans; Pfammatter, Thomas; Wildi, Stefan; Bauerfeind, Peter; Marincek, Borut; Alkadhi, Hatem

    2007-06-01

    This study was conducted to determine the ability of multi-detector-row computed tomography (CT) to identify the source and etiology of acute gastrointestinal bleeding. Eighteen patients with acute upper (n = 10) and lower (n = 8) gastrointestinal bleeding underwent 4-detector-row CT (n = 6), 16-detector-row CT (n = 11), and 64-slice CT (n = 1) with an arterial and portal venous phase of contrast enhancement. Unenhanced scans were performed in nine patients. CT scans were reviewed to determine conspicuity of bleeding source, underlying etiology, and for potential causes of false-negative prospective interpretations. Bleeding sources were prospectively identified with CT in 15 (83%) patients, and three (17%) bleeding sources were visualized in retrospect, allowing the characterization of all sources of bleeding with CT. Contrast extravasation was demonstrated with CT in all 11 patients with severe bleeding, but only in 1 of 7 patients with mild bleeding. The etiology could not be identified on unenhanced CT scans in any patient, whereas arterial-phase and portal venous-phase CT depicted etiology in 15 (83%) patients. Underlying etiology was correctly identified in all eight patients with mild GI bleeding. Multi-detector-row CT enables the identification of bleeding source and precise etiology in patients with acute gastrointestinal bleeding.

  3. Study of dual-source CT coronary angiography using low tube voltage setting in patients with low body mass index%低体质量指数患者双源CT低管电压冠状动脉成像的应用研究

    Institute of Scientific and Technical Information of China (English)

    曹建新; 王鹏; 王一民; 杨诚; 王帅

    2013-01-01

    Objective To explore the feasibility of dual-source CT coronary angiography (CTCA) using 80 kV tube voltage setting in patients with low body mass index (BMI).Methods A total of 240 patients with suspected coronary artery disease (BMI range 18.6-21.5 kg/m2) underwent dual-source CTCA.They were randomly assigned to group A (120 kV tube voltage),B (100 kV tube voltage) and C (80 kV tube voltage) based on a random number table.The contrast media dose,volume CT dose index (CTDIvol),dose length product (DLP),and effective dose (ED) were evaluated for each patient.Image noise,CT value,contrast,signal-to-noise ratio (SNR),contrast-to-noise ratio (CNR) and figure of merit (FOM) of coronary artery were all evaluated.Tie image quality of coronary artery was assessed with a threepoint scale (3 points:excellent,2 points:general,1 point:poor).Scan length,CTDIvol,DLP,ED,and contrast media dose for patients,image noise,CT value,contrast,SNR,CNR,and FOM of coronary artery were all analyzed using one-way ANOV4 analysis for 3 groups.Time windows of ECG-pulsing protocol were analyzed using x2 test,and the image quality scores of coronary artery were analyzed using Kruskal-Wallis test.Results There were no differences in scan length and Time windows of ECG-pulsing protocol among 3 groups (scan length F =2.58,P > 0.05,Time windows of ECG-pulsing protocol x2 =0.77,P > 0.05).The average contrast media doses were (82.0 ± 6.4),(76.8 ± 6.1),and (59.1 ± 3.5) ml,the average CTDIvol were(27.5 ±6.2),(18.7 ±4.4),and(11.4 ±2.4)mGy,the average DLPs were (427.7 ±92.4),(295.4 ± 77.1),and (183.9 ± 41.3) mGy · cm,and the average EDs were (6.1 ± 1.3),(4.1 ± 1.1),and (2.6 ± 0.6) msy for group A,B and C,respectively.There were statistical differences in contrast media dose,CTDIvoI,DLP,and ED among 3 groups (the F values for contrast media dose,CTDIvol,DLP,and ED were 383.08,248.13,221.05,and 234.81,respectively,all P <0.01).Compared to group A and B,the contrast media dose in group C

  4. Open source deformable image registration system for treatment planning and recurrence CT scans

    DEFF Research Database (Denmark)

    Zukauskaite, Ruta; Brink, Carsten; Hansen, Christian Rønn

    2016-01-01

    manually contoured eight anatomical regions-of-interest (ROI) twice on pCT and once on rCT. METHODS: pCT and rCT images were deformably registered using the open source software elastix. Mean surface distance (MSD) and Dice similarity coefficient (DSC) between contours were used for validation of DIR...... on pCT. DSC for DIR varied between 0.58 and 0.79 for soft tissues and was 0.79 or higher for bony structures, and correlated with the volumes of ROIs (r = 0.5, p elastix in HNSCC on planning and recurrence CT scans is feasible...

  5. Range prediction for tissue mixtures based on dual-energy CT

    CERN Document Server

    Möhler, Christian; Richter, Christian; Greilich, Steffen

    2016-01-01

    The use of dual-energy CT (DECT) potentially decreases range uncertainties in proton and ion therapy treatment planning via determination of the involved physical target quantities. For eventual clinical application, the correct treatment of tissue mixtures and heterogeneities is an essential feature, as they naturally occur within a patient's CT. Here, we present how existing methods for DECT-based ion-range prediction can be modified in order to incorporate proper mixing behavior on several structural levels. Our approach is based on the factorization of the stopping-power ratio into the relative electron density and the relative stopping number. The latter is confined for tissue between about 0.95 and 1.02 at a therapeutic beam energy of 200 MeV/u and depends on the I-value. We show that convenient mixing and averaging properties arise by relating the relative stopping number to the relative cross section obtained by DECT. From this, a maximum uncertainty of the stopping-power ratio prediction below 1% is ...

  6. Range prediction for tissue mixtures based on dual-energy CT

    Science.gov (United States)

    Möhler, Christian; Wohlfahrt, Patrick; Richter, Christian; Greilich, Steffen

    2016-06-01

    The use of dual-energy CT (DECT) potentially decreases range uncertainties in proton and ion therapy treatment planning via determination of the involved physical target quantities. For eventual clinical application, the correct treatment of tissue mixtures and heterogeneities is an essential feature, as they naturally occur within a patient’s CT. Here, we present how existing methods for DECT-based ion-range prediction can be modified in order to incorporate proper mixing behavior on several structural levels. Our approach is based on the factorization of the stopping-power ratio into the relative electron density and the relative stopping number. The latter is confined for tissue between about 0.95 and 1.02 at a therapeutic beam energy of 200 MeV u-1 and depends on the I-value. We show that convenient mixing and averaging properties arise by relating the relative stopping number to the relative cross section obtained by DECT. From this, a maximum uncertainty of the stopping-power ratio prediction below 1% is suggested for arbitrary mixtures of human body tissues.

  7. Pre-reconstruction three-material decomposition in dual-energy CT

    Science.gov (United States)

    Yu, Lifeng; Liu, Xin; McCollough, Cynthia H.

    2009-02-01

    It is of clinical interest to quantify the concentration of materials in a three-component mixture with known chemical compositions, such as bone-mineral density (BMD) in a trabecular bone composed of calcium hydroxyappitite (CaHA), yellow- and red-marrow, and iron content in the liver composed of soft tissue, fat, and iron. Both pre- and postreconstruction dual-energy CT methods have been used to achieve this goal. The pre-reconstruction method is more accurate due to the elimination of beam-hardening artifacts. After obtaining the equivalent densities of the two basis materials, however, it is unclear how to accurately estimate the concentration of each material in the presence of the third material in the mixture. In this work, we present a pre-reconstruction three-material decomposition method in dualenergy CT to quantify the concentration of each material in a three-component mixture with known chemical compositions. This method employs a specific physical constraint on the equivalent densities of the two basis materials obtained from the conventional basis-material decomposition. We evaluated this method using simulation studies on two types of three-component mixtures: bone-water-fat and Iron-water-CaHA. The results demonstrated that an accurate estimation of the concentration for each material can be achieved with the proposed method.

  8. Performance of dual-energy CT with tin filter technology for the discrimination of renal cysts and enhancing masses.

    Science.gov (United States)

    Leschka, Sebastian; Stolzmann, Paul; Baumüller, Stephan; Scheffel, Hans; Desbiolles, Lotus; Schmid, Bernhard; Marincek, Borut; Alkadhi, Hatem

    2010-04-01

    To assess the performance of dual-energy computed tomography (DECT) equipped with the new tin filter technology to classify phantom renal lesions as cysts or enhancing masses. Forty spherical lesion proxies ranging in diameter from 6 to 27 mm were filled with either distilled water (n = 10) representing cysts or titrated iodinated contrast solutions with a concentration of 0.45 (n = 10), 0.9 (n = 10), and 1.8 mg/mL (n = 10) representing enhancing masses. The lesion proxies were placed in a 12-cm diameter renal phantom containing minced beef and submerged in a 28-cm water bath. DECT was performed using the new dual-source CT system (Definition Flash, Siemens Healthcare, Forchheim, Germany) allowing for an improved energy separation by using a tin filter. DECT was performed at tube voltages of 140/80 kV without the tin filter (protocol A) and with tin filter (protocol B). The tube current time product was selected in each protocol to achieve a constant CTDI (computed tomography dose index) with both protocols of 19 mGy (full dose), 9.5 mGy (half dose), and 4.8 mGy (quarter dose). Two blinded readers classified each lesion as a cyst or enhancing mass by using iodine overlay (IO) images. One reader measured the CT numbers of each lesion at 120 kV, in the IO, linear blending (LB), and virtual noncontrast (VNC) images. The CT numbers of the lesions at 120 kV were 0.1 +/- 0.7 HU (0 mg iodine/mL), 9.1 +/- 0.7 HU (0.45 mg/mL), 18.1 +/- 1.4 HU (0.9 mg/mL), and 37.6 +/- 1.6 HU (1.8 mg/mL). Mean diameter of the lesion proxies filled with water or different iodine concentrations was similar (P = 0.38). Image noise was not significantly different in protocols A and B at the corresponding dose levels. At full dose, protocol A had a sensitivity of 93% and a specificity of 60% for discriminating renal lesions. Sensitivity and specificity declined to 84% and 38% at quarter dose. In protocol B, sensitivity was 100% and specificity was 90% at full dose and 93% and 70% at quarter dose

  9. Dual energy CT kidney stone differentiation in photon counting computed tomography

    Science.gov (United States)

    Gutjahr, R.; Polster, C.; Henning, A.; Kappler, S.; Leng, S.; McCollough, C. H.; Sedlmair, M. U.; Schmidt, B.; Krauss, B.; Flohr, T. G.

    2017-03-01

    This study evaluates the capabilities of a whole-body photon counting CT system to differentiate between four common kidney stone materials, namely uric acid (UA), calcium oxalate monohydrate (COM), cystine (CYS), and apatite (APA) ex vivo. Two different x-ray spectra (120 kV and 140 kV) were applied and two acquisition modes were investigated. The macro-mode generates two energy threshold based image-volumes and two energy bin based image-volumes. In the chesspattern-mode four energy thresholds are applied. A virtual low energy image, as well as a virtual high energy image are derived from initial threshold-based images, while considering their statistically correlated nature. The energy bin based images of the macro-mode, as well as the virtual low and high energy image of the chesspattern-mode serve as input for our dual energy evaluation. The dual energy ratio of the individually segmented kidney stones were utilized to quantify the discriminability of the different materials. The dual energy ratios of the two acquisition modes showed high correlation for both applied spectra. Wilcoxon-rank sum tests and the evaluation of the area under the receiver operating characteristics curves suggest that the UA kidney stones are best differentiable from all other materials (AUC = 1.0), followed by CYS (AUC ≍ 0.9 compared against COM and APA). COM and APA, however, are hardly distinguishable (AUC between 0.63 and 0.76). The results hold true for the measurements of both spectra and both acquisition modes.

  10. 双源CT FAST DE技术在去除腰椎金属内固定物伪影中的价值%Clinic Value of FAST DE Technique on Dual-Source CT in Reducing Metallic Artefacts of Lumbar Fusion

    Institute of Scientific and Technical Information of China (English)

    王淑贤; 万娅敏; 谭红娜; 郭华; 高剑波; 刘杰

    2016-01-01

    目的 探讨西门子双源CT FAST DE技术在去除腰椎金属内固定物伪影中的价值.方法 选取35例我院腰椎金属内固定物置入术后复查的病人,行双源CT的双能量扫描模式,并选择FAST DE序列,得到100 kV、140kV、混能图像及FAST DE的图像.将FAST DE图像设置为A组,100 kV、140 kV图像用单能谱技术后处理得到120keV的图像设置为B组.由2名5年以上工作经验的影像诊断医师对两组图像进行评分,并对A、B两组图像得分进行统计学分析,采用配对资料的符号秩和检验.结果 A、B两组均能提供较好的图像质量,且两组图像得分差异没有统计学意义(P=0.29).但A组较B组的优势在于省去了繁琐的后处理工作,更快速更高效的完成检查.结论 双源CT的FAST DE技术在去除腰椎金属内固定物伪影方面,在相同的图像质量前提下,比单能谱技术更快速、便捷.

  11. 双源CT冠状动脉血管成像中降低团注追踪触发监测频率的可行性研究%Feasibility of reducing bolus-tracking monitor frequency in coronary CT angiology with dual-source CT

    Institute of Scientific and Technical Information of China (English)

    韩宇欣; 王辉; 汤漪凡; 王涛; 吕蓉; 于长路; 刘金梦

    2016-01-01

    Objective To investigate the feasibility of reducing bolus⁃tracking monitor frequency in coronary CT angiography (CTA). Methods This prospective study including 120 patients with suspected coronary artery disease (CAD). According to the examination registration order, the patients were divided into groups A, B and C (n=40 for each group). All patients underwent coronary CTA with bolus⁃tracking technology, and were monitored at 10 s after the injection of contrast. The monitoring frequency of bolus⁃tracking for Group A was every 1.14 s, that for Group B was every 1.47 s , and for Group C was every 2.00 s, while the trigger threshold was set as 100 HU. To evaluate the image quality, the objective evaluation included signal noise ratio (SNR) and contrast noise ratio (CNR) of aorta (AO), CNR of left main coronary artery (LM) and right coronary artery (RCA), and the subjective score was recorded for each coronary artery segment. The monitoring times when CT density of the region of interest (ROI) reached the threshold, the CT value and the effective dose (ED) in the 3 groups were recorded. Objective image quality, monitoring parameters and radiation dose were compared using analysis of variance method, subjective image quality was compared withχ2 tests. Results There was no significant difference in AO (SNR and CNR), LM (CNR) and RCA (CNR) among the 3 groups, respectively (P>0.05). Subjective image quality scores of groups A, B, C were (1.879±0.042), (1.876±0.042), (1.881±0.042 ), with no significant difference (χ2=0.003,P>0.05). The monitoring times of to reach the threshold in groups A, B, C were (4.78±2.37), (3.76±1.39), (2.77±0.99), and ED were (0.058±0.031),(0.031±0.011), (0.021±0.007) mSv, with the significant difference (F=9.009, 31.998, respectively, P0.05)。A、B、C组的图像质量评分分别为(1.879±0.042)、(1.876±0.042)、(1.881±0.042)分,差异无统计学意义(χ2=0.003,P>0.05)。A、B、C组达到阈值

  12. On-chip dual comb source for spectroscopy

    CERN Document Server

    Dutt, Avik; Ji, Xingchen; Cardenas, Jaime; Okawachi, Yoshitomo; Luke, Kevin; Gaeta, Alexander L; Lipson, Michal

    2016-01-01

    Dual-comb spectroscopy is a powerful technique for real-time, broadband optical sampling of molecular spectra which requires no moving components. Recent developments with microresonator-based platforms have enabled frequency combs at the chip scale. However, the need to precisely match the resonance wavelengths of distinct high-quality-factor microcavities has hindered the development of an on-chip dual comb source. Here, we report the first simultaneous generation of two microresonator combs on the same chip from a single laser. The combs span a broad bandwidth of 51 THz around a wavelength of 1.56 $\\mu$m. We demonstrate low-noise operation of both frequency combs by deterministically tuning into soliton mode-locked states using integrated microheaters, resulting in narrow ($<$ 10 kHz) microwave beatnotes. We further use one mode-locked comb as a reference to probe the formation dynamics of the other comb, thus introducing a technique to investigate comb evolution without auxiliary lasers or microwave os...

  13. Dual-time-point FDG-PET/CT Imaging of Temporal Bone Chondroblastoma: A Report of Two Cases.

    Science.gov (United States)

    Toriihara, Akira; Tsunoda, Atsunobu; Takemoto, Akira; Kubota, Kazunori; Machida, Youichi; Tateishi, Ukihide

    2015-01-01

    Temporal bone chondroblastoma is an extremely rare benign bone tumor. We encountered two cases showing similar imaging findings on computed tomography (CT), magnetic resonance imaging (MRI), and dual-time-point (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET)/CT. In both cases, CT images revealed temporal bone defects and sclerotic changes around the tumor. Most parts of the tumor showed low signal intensity on T2-weighted MRI images and non-uniform enhancement on gadolinium contrast-enhanced T1-weighted images. No increase in signal intensity was noted in diffusion-weighted images. Dual-time-point PET/CT showed markedly elevated (18)F-FDG uptake, which increased from the early to delayed phase. Nevertheless, immunohistochemical analysis of the resected tumor tissue revealed weak expression of glucose transporter-1 and hexokinase II in both tumors. Temporal bone tumors, showing markedly elevated (18)F-FDG uptake, which increases from the early to delayed phase on PET/CT images, may be diagnosed as malignant bone tumors. Therefore, the differential diagnosis should include chondroblastoma in combination with its characteristic findings on CT and MRI.

  14. Dual-time-point FDG-PET/CT Imaging of Temporal Bone Chondroblastoma: A Report of Two Cases

    Directory of Open Access Journals (Sweden)

    Akira Toriihara

    2015-07-01

    Full Text Available Temporal bone chondroblastoma is an extremely rare benign bone tumor. We encountered two cases showing similar imaging findings on computed tomography (CT, magnetic resonance imaging (MRI, and dual-time-point 18F-fluorodeoxyglucose (18F-FDG positron emission tomography (PET/CT. In both cases, CT images revealed temporal bone defects and sclerotic changes around the tumor. Most parts of the tumor showed low signal intensity on T2- weighted MRI images and non-uniform enhancement on gadolinium contrast-enhanced T1-weighted images. No increase in signal intensity was noted in diffusion-weighted images. Dual-time-point PET/CT showed markedly elevated 18F-FDG uptake, which increased from the early to delayed phase. Nevertheless, immunohistochemical analysis of the resected tumor tissue revealed weak expression of glucose transporter-1 and hexokinase II in both tumors. Temporal bone tumors, showing markedly elevated 18F-FDG uptake, which increases from the early to delayed phase on PET/CT images, may be diagnosed as malignant bone tumors. Therefore, the differential diagnosis should include chondroblastoma in combination with its characteristic findings on CT and MRI.

  15. Metal artefact reduction in gemstone spectral imaging dual-energy CT with and without metal artefact reduction software

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young Han; Song, Ho-Taek; Kim, Sungjun; Suh, Jin-Suck [Yonsei University College of Medicine, Department of Radiology, Research Institute of Radiological Science, Medical Convergence Research Institute, and Severance Biomedical Science Institute, Seoul (Korea, Republic of); Park, Kwan Kyu [Yonsei University College of Medicine, Department of Orthopaedic Surgery, Seoul (Korea, Republic of)

    2012-06-15

    To assess the usefulness of gemstone spectral imaging (GSI) dual-energy CT (DECT) with/without metal artefact reduction software (MARs). The DECTs were performed using fast kV-switching GSI between 80 and 140 kV. The CT data were retro-reconstructed with/without MARs, by different displayed fields-of-view (DFOV), and with synthesised monochromatic energy in the range 40-140 keV. A phantom study of size and CT numbers was performed in a titanium plate and a stainless steel plate. A clinical study was performed in 26 patients with metallic hardware. All images were retrospectively reviewed in terms of the visualisation of periprosthetic regions and the severity of beam-hardening artefacts by using a five-point scale. The GSI-MARs reconstruction can markedly reduce the metal-related artefacts, and the image quality was affected by the prosthesis composition and DFOV. The spectral CT numbers of the prosthesis and periprosthetic regions showed different patterns on stainless steel and titanium plates. Dual-energy CT with GSI-MARs can reduce metal-related artefacts and improve the delineation of the prosthesis and periprosthetic region. We should be cautious when using GSI-MARs because the image quality was affected by the prosthesis composition, energy (in keV) and DFOV. The metallic composition and size should be considered in metallic imaging with GSI-MARs reconstruction. circle Metal-related artefacts can be troublesome on musculoskeletal computed tomography (CT). circle Gemstone spectral imaging (GSI) with dual-energy CT (DECT) offers a novel solution circle GSI and metallic artefact reduction software (GSI-MAR) can markedly reduce these artefacts. circle However image quality is influenced by the prosthesis composition and other parameters. circle We should be aware about potential overcorrection when using GSI-MARs. (orig.)

  16. Collateral Ventilation to Congenital Hyperlucent Lung Lesions Assessed on Xenon-Enhanced Dynamic Dual-Energy CT: an Initial Experience

    Energy Technology Data Exchange (ETDEWEB)

    Goo, Hyun Woo; Yang, Dong Hyun; Kim, Nam Kug; Park, Seung Il; Kim, Dong Kwan; Kim, Ellen Ai Rhan [Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    2011-02-15

    We wanted to evaluate the resistance to collateral ventilation in congenital hyperlucent lung lesions and to correlate that with the anatomic findings on xenon-enhanced dynamic dual-energy CT. Xenon-enhanced dynamic dual-energy CT was successfully and safely performed in eight children (median age: 5.5 years, 4 boys and 4 girls) with congenital hyperlucent lung lesions. Functional assessment of the lung lesions on the xenon map was done, including performing a time-xenon value curve analysis and assessing the amplitude of xenon enhancement (A) value, the rate of xenon enhancement (K) value and the time of arrival value. Based on the A value, the lung lesions were categorized into high or low (A value > 10 Hounsfi eld unit [HU]) resistance to collateral ventilation. In addition, the morphologic CT findings of the lung lesions, including cyst, mucocele and an accessory or incomplete fissure, were assessed on the weighted-average CT images. The xenon-enhanced CT radiation dose was estimated. Five of the eight lung lesions were categorized into the high resistance group and three lesions were categorized into the low resistance group. The A and K values in the normal lung were higher than those in the low resistance group. The time of arrival values were delayed in the low resistance group. Cysts were identified in five lesions, mucocele in four, accessory fissure in three and incomplete fissure in two. Either cyst or an accessory fissure was seen in four of the five lesions showing high resistance to collateral ventilation. The xenon-enhanced CT radiation dose was 2.3 {+-} 0.6 mSv. Xenon-enhanced dynamic dual-energy CT can help visualize and quantitate various degrees of collateral ventilation to congenital hyperlucent lung lesions in addition to assessing the anatomic details of the lung

  17. Application of single- and dual-energy CT brain tissue segmentation to PET monitoring of proton therapy

    Science.gov (United States)

    Berndt, Bianca; Landry, Guillaume; Schwarz, Florian; Tessonnier, Thomas; Kamp, Florian; Dedes, George; Thieke, Christian; Würl, Matthias; Kurz, Christopher; Ganswindt, Ute; Verhaegen, Frank; Debus, Jürgen; Belka, Claus; Sommer, Wieland; Reiser, Maximilian; Bauer, Julia; Parodi, Katia

    2017-03-01

    The purpose of this work was to evaluate the ability of single and dual energy computed tomography (SECT, DECT) to estimate tissue composition and density for usage in Monte Carlo (MC) simulations of irradiation induced β + activity distributions. This was done to assess the impact on positron emission tomography (PET) range verification in proton therapy. A DECT-based brain tissue segmentation method was developed for white matter (WM), grey matter (GM) and cerebrospinal fluid (CSF). The elemental composition of reference tissues was assigned to closest CT numbers in DECT space (DECTdist). The method was also applied to SECT data (SECTdist). In a validation experiment, the proton irradiation induced PET activity of three brain equivalent solutions (BES) was compared to simulations based on different tissue segmentations. Five patients scanned with a dual source DECT scanner were analyzed to compare the different segmentation methods. A single magnetic resonance (MR) scan was used for comparison with an established segmentation toolkit. Additionally, one patient with SECT and post-treatment PET scans was investigated. For BES, DECTdist and SECTdist reduced differences to the reference simulation by up to 62% when compared to the conventional stoichiometric segmentation (SECTSchneider). In comparison to MR brain segmentation, Dice similarity coefficients for WM, GM and CSF were 0.61, 0.67 and 0.66 for DECTdist and 0.54, 0.41 and 0.66 for SECTdist. MC simulations of PET treatment verification in patients showed important differences between DECTdist/SECTdist and SECTSchneider for patients with large CSF areas within the treatment field but not in WM and GM. Differences could be misinterpreted as PET derived range shifts of up to 4 mm. DECTdist and SECTdist yielded comparable activity distributions, and comparison of SECTdist to a measured patient PET scan showed improved agreement when compared to SECTSchneider. The agreement between predicted and measured PET

  18. SU-E-I-98: Dose Comparison for Pulmonary Embolism CT Studies: Single Energy Vs. Dual Energy

    Energy Technology Data Exchange (ETDEWEB)

    Mahmood, U; Erdi, Y [Memorial Sloan Kettering Cancer Center, NY, NY (United States)

    2014-06-01

    Purpose: The purpose of this study was to assess and compare the size specific dose estimate (SSDE), dose length product (DLP) and noise relationship for pulmonary embolism studies evaluated by single source dual energy computed tomography (DECT) against conventional CT (CCT) studies in a busy cancer center and to determine the dose savings provided by DECT. Methods: An IRB-approved retrospective study was performed to determine the CTDIvol and DLP from a subset of patients scanned with both DECT and CCT over the past five years. We were able to identify 30 breast cancer patients (6 male, 24 female, age range 24 to 81) who had both DECT and CCT studies performed. DECT scans were performed with a GE HD 750 scanner (140/80 kVp, 480 mAs and 40 mm) and CCT scans were performed with a GE Lightspeed 16 slice scanner (120 kVp, 352 mAs, 20 mm). Image noise was measured by placing an ROI and recording the standard deviation of the mean HU along the descending aorta. Results: The average DECT patient size specific dose estimate was to be 14.2 ± 1.7 mGy as compared to 22.4 ± 2.7 mGy from CCT PE studies, which is a 37% reduction in the SSDE. The average DECT DLP was 721.8 ± 84.6 mGy-cm as compared to 981.8 ± 106.1 mGy-cm for CCT, which is a 26% decrease. Compared to CCT the image noise was found to decrease by 19% when using DECT for PE studies. Conclusion: DECT SSDE and DLP measurements indicate dose savings and image noise reduction when compared to CCT. In an environment that heavily debates CT patient doses, this study confirms the effectiveness of DECT in PE imaging.

  19. In vivo characterization of tumor vasculature using iodine and gold nanoparticles and dual energy micro-CT.

    Science.gov (United States)

    Clark, Darin P; Ghaghada, Ketan; Moding, Everett J; Kirsch, David G; Badea, Cristian T

    2013-03-21

    Tumor blood volume and vascular permeability are well established indicators of tumor angiogenesis and important predictors in cancer diagnosis, planning and treatment. In this work, we establish a novel preclinical imaging protocol which allows quantitative measurement of both metrics simultaneously. First, gold nanoparticles are injected and allowed to extravasate into the tumor, and then liposomal iodine nanoparticles are injected. Combining a previously optimized dual energy micro-CT scan using high-flux polychromatic x-ray sources (energies: 40 kVp, 80 kVp) with a novel post-reconstruction spectral filtration scheme, we are able to decompose the results into 3D iodine and gold maps, allowing simultaneous measurement of extravasated gold and intravascular iodine concentrations. Using a digital resolution phantom, the mean limits of detectability (mean CNR = 5) for each element are determined to be 2.3 mg mL(-1) (18 mM) for iodine and 1.0 mg mL(-1) (5.1 mM) for gold, well within the observed in vivo concentrations of each element (I: 0-24 mg mL(-1), Au: 0-9 mg mL(-1)) and a factor of 10 improvement over the limits without post-reconstruction spectral filtration. Using a calibration phantom, these limits are validated and an optimal sensitivity matrix for performing decomposition using our micro-CT system is derived. Finally, using a primary mouse model of soft-tissue sarcoma, we demonstrate the in vivo application of the protocol to measure fractional blood volume and vascular permeability over the course of five days of active tumor growth.

  20. In vivo characterization of tumor vasculature using iodine and gold nanoparticles and dual energy micro-CT

    Science.gov (United States)

    Clark, Darin P.; Ghaghada, Ketan; Moding, Everett J.; Kirsch, David G.; Badea, Cristian T.

    2013-03-01

    Tumor blood volume and vascular permeability are well established indicators of tumor angiogenesis and important predictors in cancer diagnosis, planning and treatment. In this work, we establish a novel preclinical imaging protocol which allows quantitative measurement of both metrics simultaneously. First, gold nanoparticles are injected and allowed to extravasate into the tumor, and then liposomal iodine nanoparticles are injected. Combining a previously optimized dual energy micro-CT scan using high-flux polychromatic x-ray sources (energies: 40 kVp, 80 kVp) with a novel post-reconstruction spectral filtration scheme, we are able to decompose the results into 3D iodine and gold maps, allowing simultaneous measurement of extravasated gold and intravascular iodine concentrations. Using a digital resolution phantom, the mean limits of detectability (mean CNR = 5) for each element are determined to be 2.3 mg mL-1 (18 mM) for iodine and 1.0 mg mL-1 (5.1 mM) for gold, well within the observed in vivo concentrations of each element (I: 0-24 mg mL-1, Au: 0-9 mg mL-1) and a factor of 10 improvement over the limits without post-reconstruction spectral filtration. Using a calibration phantom, these limits are validated and an optimal sensitivity matrix for performing decomposition using our micro-CT system is derived. Finally, using a primary mouse model of soft-tissue sarcoma, we demonstrate the in vivo application of the protocol to measure fractional blood volume and vascular permeability over the course of five days of active tumor growth.

  1. Absolute measurement of the effective atomic number and the electron density by using dual-energy CT images

    Science.gov (United States)

    Kim, Dae-Hong; Lee, Won-Hyung; Jeon, Sung-Soo; Kim, Hee-Joung

    2012-12-01

    Material decomposition using dual-energy and material-selective techniques was performed using computed-tomography (CT)-generated reconstructed images. Previous work using the dual-energy method focused on extracting the effective atomic number and the electron density of materials to confirm the dosimetric accuracy in radiation therapy. Dual-energy methods mostly depend on the device generating the X-rays, such as a synchrotron, and on dose verification for radiation treatment planning. Information obtained from CT imaging is important both in diagnosis and in planning radiation therapy. In a clinical setting, CT images are usually displayed as Houndsfield units (HU), which are extracted from the attenuation coefficient of a material. The attenuation coefficient is calculated using the effective atomic number and the electron density of a material; thus, information expressed in HU can be converted into the effective atomic number and the electron density by using the dual-energy equation. This study was performed using realistic Xray spectra to differentiate between the contrast media and plaque in vascular images. Our results suggest that the effective atomic number and electron density are useful in distinguishing between two adjacent materials with similar HUs.

  2. Reconstruction of limited-angle dual-energy CT using mutual learning and cross-estimation (MLCE)

    Science.gov (United States)

    Zhang, Huayu; Xing, Yuxiang

    2016-03-01

    Dual-energy CT (DECT) imaging has gained a lot of attenuation because of its capability to discriminate materials. We proposes a flexible DECT scan strategy which can be realized on a system with general X-ray sources and detectors. In order to lower dose and scanning time, our DECT acquires two projections data sets on two arcs of limited-angular coverage (one for each energy) respectively. Meanwhile, a certain number of rays from two data sets form conjugate sampling pairs. Our reconstruction method for such a DECT scan mainly tackles the consequent limited-angle problem. Using the idea of artificial neural network, we excavate the connection between projections at two different energies by constructing a relationship between the linear attenuation coefficient of the high energy and that of the low one. We use this relationship to cross-estimate missing projections and reconstruct attenuation images from an augmented data set including projections at views covered by itself (projections collected in scanning) and by the other energy (projections estimated) for each energy respectively. Validated by our numerical experiment on a dental phantom with rather complex structures, our DECT is effective in recovering small structures in severe limited-angle situations. This DECT scanning strategy can much broaden DECT design in reality.

  3. Application of dual-energy spectral CT imaging in differential diagnosis of bladder cancer and benign prostate hyperplasia

    Science.gov (United States)

    Chen, Anliang; Liu, Ailian; Liu, Jinghong; Tian, Shifeng; Wang, Heqing; Liu, Yijun

    2016-01-01

    Abstract The aim of this study was to explore the clinical value of dual-energy spectral CT imaging in the differential diagnosis between bladder cancer and benign prostate hyperplasia (BPH). We retrospectively analyzed images of 118 patients who received pelvic dual-energy spectral CT imaging. These patients were later confirmed to have bladder cancer in 61 patients and BPH in 57 patients. CT values of the 2 lesion types from 40 to 140 keV were measured from the monochromatic spectral CT image to generate spectral HU curves. The slope of the spectral curve and the lesion effective atomic number were calculated. The measured parameters were analyzed with independent-sample Mann-Whitney U test. There was a statistically significant difference in CT value between the 2 groups from 40 to 90 keV, with the biggest difference at 40 keV (median and interquartile range: 83.3 HU and 22.9 HU vs 60.6 HU and 16.7 HU, Z = 5.932, P benign prostate hyperplasia. PMID:28033269

  4. Learning-Based Object Identification and Segmentation Using Dual-Energy CT Images for Security.

    Science.gov (United States)

    Martin, Limor; Tuysuzoglu, Ahmet; Karl, W Clem; Ishwar, Prakash

    2015-11-01

    In recent years, baggage screening at airports has included the use of dual-energy X-ray computed tomography (DECT), an advanced technology for nondestructive evaluation. The main challenge remains to reliably find and identify threat objects in the bag from DECT data. This task is particularly hard due to the wide variety of objects, the high clutter, and the presence of metal, which causes streaks and shading in the scanner images. Image noise and artifacts are generally much more severe than in medical CT and can lead to splitting of objects and inaccurate object labeling. The conventional approach performs object segmentation and material identification in two decoupled processes. Dual-energy information is typically not used for the segmentation, and object localization is not explicitly used to stabilize the material parameter estimates. We propose a novel learning-based framework for joint segmentation and identification of objects directly from volumetric DECT images, which is robust to streaks, noise and variability due to clutter. We focus on segmenting and identifying a small set of objects of interest with characteristics that are learned from training images, and consider everything else as background. We include data weighting to mitigate metal artifacts and incorporate an object boundary field to reduce object splitting. The overall formulation is posed as a multilabel discrete optimization problem and solved using an efficient graph-cut algorithm. We test the method on real data and show its potential for producing accurate labels of the objects of interest without splits in the presence of metal and clutter.

  5. WE-D-BRF-05: Quantitative Dual-Energy CT Imaging for Proton Stopping Power Computation

    Energy Technology Data Exchange (ETDEWEB)

    Han, D; Williamson, J [Virginia Commonwealth University, Richmond, VA (United States); Siebers, J [University of Virginia Health System, Charlottesville, VA (United States)

    2014-06-15

    Purpose: To extend the two-parameter separable basis-vector model (BVM) to estimation of proton stopping power from dual-energy CT (DECT) imaging. Methods: BVM assumes that the photon cross sections of any unknown material can be represented as a linear combination of the corresponding quantities for two bracketing basis materials. We show that both the electron density (ρe) and mean excitation energy (Iex) can be modeled by BVM, enabling stopping power to be estimated from the Bethe-Bloch equation. We have implemented an idealized post-processing dual energy imaging (pDECT) simulation consisting of monogenetic 45 keV and 80 keV scanning beams with polystyrene-water and water-CaCl2 solution basis pairs for soft tissues and bony tissues, respectively. The coefficients of 24 standard ICRU tissue compositions were estimated by pDECT. The corresponding ρe, Iex, and stopping power tables were evaluated via BVM and compared to tabulated ICRU 44 reference values. Results: BVM-based pDECT was found to estimate ρe and Iex with average and maximum errors of 0.5% and 2%, respectively, for the 24 tissues. Proton stopping power values at 175 MeV, show average/maximum errors of 0.8%/1.4%. For adipose, muscle and bone, these errors result range prediction accuracies less than 1%. Conclusion: A new two-parameter separable DECT model (BVM) for estimating proton stopping power was developed. Compared to competing parametric fit DECT models, BVM has the comparable prediction accuracy without necessitating iterative solution of nonlinear equations or a sample-dependent empirical relationship between effective atomic number and Iex. Based on the proton BVM, an efficient iterative statistical DECT reconstruction model is under development.

  6. Collateral ventilation quantification using xenon-enhanced dynamic dual-energy CT: Differences between canine and swine models of bronchial occlusion

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun Ah; Goo, Jin Mo; Park, Sang Joon; Lee, Chang Hyun; Park, Chng Min [Dept. of Radiology, Seoul National University College of Medicine and Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul (Korea, Republic of)

    2015-06-15

    The aim of this study was to evaluate whether the difference in the degree of collateral ventilation between canine and swine models of bronchial obstruction could be detected by using xenon-enhanced dynamic dual-energy CT. Eight mongrel dogs and six pigs underwent dynamic dual-energy scanning of 64-slice dual-source CT at 12-second interval for 2-minute wash-in period (60% xenon) and at 24-second interval for 3-minute wash-out period with segmental bronchus occluded. Ventilation parameters of magnitude (A value), maximal slope, velocity (K value), and time-to-peak (TTP) enhancement were calculated from dynamic xenon maps using exponential function of Kety model. A larger difference in A value between parenchyma was observed in pigs than in dogs (absolute difference, -33.0 +/- 5.0 Hounsfield units [HU] vs. -2.8 +/- 7.1 HU, p = 0.001; normalized percentage difference, -79.8 +/- 1.8% vs. -5.4 +/- 16.4%, p = 0.0007). Mean maximal slopes in both periods in the occluded parenchyma only decreased in pigs (all p < 0.05). K values of both periods were not different (p = 0.892) in dogs. However, a significant (p = 0.027) difference was found in pigs in the wash-in period. TTP was delayed in the occluded parenchyma in pigs (p = 0.013) but not in dogs (p = 0.892). Xenon-ventilation CT allows the quantification of collateral ventilation and detection of differences between canine and swine models of bronchial obstruction.

  7. Total variation superiorization in dual-energy CT reconstruction for proton therapy treatment planning

    Science.gov (United States)

    Zhu, Jiahua; Penfold, Scott

    2017-04-01

    Proton therapy is a precise form of radiotherapy in which the range of an energetic beam of protons within a patient must be accurately known. The current approach based on single-energy computed tomography (SECT) can lead to uncertainties in the proton range of approximately 3%. This range of uncertainty may lead to under-dosing of the tumour or over-dosing of healthy tissues. Dual-energy CT (DECT) theoretically has the potential to reduce these range uncertainties by quantifying electron density and the effective atomic number. In practice, however, DECT images reconstructed with filtered backprojection (FBP) tend to suffer from high levels of noise. The objective of the current work was to examine the effect of total variation superiorization (TVS) on proton therapy planning accuracy when compared with FBP. A virtual CT scanner was created with the Monte Carlo toolkit Geant4. Tomographic images were reconstructed with FBP and TVS combined with diagonally relaxed orthogonal projections (TVS-DROP). A total variation minimization (TVM) filter was also applied to the image reconstructed with FBP (FBP-TVM). Quantitative accuracy and variance of proton relative stopping power (RSP) derived from each image set was assessed. Mean RSPs were comparable with each image; however, the standard deviation of pixel values with TVS-DROP was reduced by a factor of 0.44 compared with the FBP image and a factor of 0.66 when compared with the FBP-TVM image. Proton doses calculated with the TVS-DROP image set were also better able to predict a reference dose distribution when compared with the FBP and FBP-TVM image sets. The study demonstrated the potential advantages of TVS-DROP as an image reconstruction method for DECT applied to proton therapy treatment planning.

  8. Liver fat quantification using fast kVp-switching dual energy CT

    Science.gov (United States)

    Kriston, Andras; Mendonça, Paulo; Silva, Alvin; Paden, Robert G.; Pavlicek, William; Sahani, Dushyant; Janos Kis, Benedek; Rusko, Laszlo; Okerlund, Darin; Bhotika, Rahul

    2011-03-01

    Nonalcoholic steatohepatitis (NASH) is a liver disease that occurs in patients that lack a history of the well-proven association of alcohol use. A major symptom of NASH is increased fat deposition in the liver. Gemstone Spectral Imaging (GSI) with fast kVp-switching enables projection-based material decomposition, offering the opportunity to accurately characterize tissue types, e.g., fat and healthy liver tissue, based on their energy-sensitive material attenuation and density. We describe our pilot efforts to apply GSI to locate and quantify the amount of fat deposition in the liver. Two approaches are presented, one that computes percentage fat from the difference in HU values at high and low energies and the second based on directly computing fat volume fraction at each voxel using multi-material decomposition. Simulation software was used to create a phantom with a set of concentric rings, each composed of fat and soft tissue in different relative amounts with attenuation values obtained from the National Institute of Standards and Technology. Monte Carlo 80 and 140 kVp X-ray projections were acquired and CT images of the phantom were reconstructed. Results demonstrated the sensitivity of dual energy CT to the presence of fat and its ability to distinguish fat from soft tissue. Additionally, actual patient (liver) datasets were acquired using GSI and monochromatic images at 70 and 140 keV were reconstructed. Preliminary results demonstrate a tissue sensitivity that appears sufficient to quantify fat content with a degree of accuracy as may be needed for non-invasive clinical assessment of NASH.

  9. Evaluation of a dual-room sliding gantry CT concept for workflow optimisation in polytrauma and regular in- and outpatient management

    Energy Technology Data Exchange (ETDEWEB)

    Frellesen, Claudia; Boettcher, Marie; Wichmann, Julian L.; Drieske, Martina; Kerl, J. Matthias; Lehnert, Thomas [Department of Diagnostic and Interventional Radiology, Clinic of the Goethe University, Frankfurt (Germany); Nau, Christoph; Geiger, Emmanuel; Wutzler, Sebastian [Department of Trauma, Reconstructive and Hand Surgery, Clinic of the Goethe University, Frankfurt (Germany); Ackermann, Hanns [Department of Biostatistics and Mathematical Modelling, Clinic of the Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt (Germany); Vogl, Thomas J. [Department of Diagnostic and Interventional Radiology, Clinic of the Goethe University, Frankfurt (Germany); Bauer, Ralf W., E-mail: ralfwbauer@aol.com [Department of Diagnostic and Interventional Radiology, Clinic of the Goethe University, Frankfurt (Germany)

    2015-01-15

    Highlights: • A sliding gantry trauma room CT solution facilitates significantly faster polytrauma management. • Faster and more efficient resumption of regularly scheduled patients due to a two room solution is supported. • Sliding gantry CT achieves the same patient throughput as two separate conventional CT devices. - Abstract: Objectives: To reveal the impact on workflow from introducing a dual-room sliding gantry CT to the trauma room for polytrauma and regularly scheduled in- outpatients with regard to efficiency and degree of capacity utilisation. Materials and methods: Time analysis was performed for 30 polytrauma patients each in 2 different trauma room settings, the new trauma room comprising a sliding gantry CT, the old one a stationary single-room CT. Complete trauma room and diagnostic workup times were manually measured and compared for both groups. In a third scenario, the number of CT scans performed with one single sliding gantry CT and the two-room concept was compared to the number of CT scans performed on two separate regular CT units in a 5 days clinical routine sample. Results: Patients demographics and type of CT examinations were comparable for all patient groups. The median time from patient arrival in the trauma room until beginning of CT scanning was 6 min shorter for the sliding gantry CT group (21 vs.15 min). Sliding gantry CT embedded in a two-room solution achieved 252 CT scans in 5 working days, compared to 250 CT scans on two separate regular CT units with the same man power. Conclusions: Sliding gantry CT in the trauma room allows for significant time saving in the diagnostic workup of polytrauma patients and faster resumption of the regular in- outpatient's CT schedule is possible. With the same man power, the dual-room solution is able to generate the same throughput as two separate CT units.

  10. Dual-energy X-ray micro-CT imaging of hybrid Ni/Al open-cell foam

    Science.gov (United States)

    Fíla, T.; Kumpová, I.; Koudelka, P.; Zlámal, P.; Vavřík, D.; Jiroušek, O.; Jung, A.

    2016-01-01

    In this paper, we employ dual-energy X-ray microfocus tomography (DECT) measurement to develop high-resolution finite element (FE) models that can be used for the numerical assessment of the deformation behaviour of hybrid Ni/Al foam subjected to both quasi-static and dynamic compressive loading. Cubic samples of hybrid Ni/Al open-cell foam with an edge length of [15]mm were investigated by the DECT measurement. The material was prepared using AlSi7Mg0.3 aluminium foam with a mean pore size of [0.85]mm, coated with nanocrystalline nickel (crystallite size of approx. [50]nm) to form a surface layer with a theoretical thickness of [0.075]mm. CT imaging was carried out using state-of-the-art DSCT/DECT X-ray scanner developed at Centre of Excellence Telč. The device consists of a modular orthogonal assembly of two tube-detector imaging pairs, with an independent geometry setting and shared rotational stage mounted on a complex 16-axis CNC positioning system to enable unprecedented measurement variability for highly-detailed tomographical measurements. A sample of the metal foam was simultaneously irradiated using an XWT-240-SE reflection type X-ray tube and an XWT-160-TCHR transmission type X-ray tube. An enhanced dual-source sampling strategy was used for data acquisition. X-ray images were taken using XRD1622 large area GOS scintillator flat panel detectors with an active area of [410 × 410]mm and resolution [2048 × 2048]pixels. Tomographic scanning was performed in 1,200 projections with a 0.3 degree angular step to improve the accuracy of the generated models due to the very complex microstructure and high attenuation of the investigated material. Reconstructed data was processed using a dual-energy algorithm, and was used for the development of a 3D model and voxel model of the foam. The selected parameters of the models were compared with nominal parameters of the actual foam and showed good correlation.

  11. A dual energy CT study on vascular effects of gold nanoparticles in radiation therapy

    Science.gov (United States)

    Ashton, Jeffrey R.; Hoye, Jocelyn; Deland, Katherine; Whitley, Melodi; Qi, Yi; Moding, Everett; Kirsch, David G.; West, Jennifer; Badea, Cristian T.

    2016-03-01

    Gold nanoparticles (AuNPs) are emerging as promising agents for both cancer therapy and CT imaging. AuNPs are delivered to tumors via the enhanced permeability and retention effect and they preferentially accumulate in close proximity to the tumor blood vessels. AuNPs produce low-energy, short-range photoelectrons during external beam radiation therapy (RT), boosting dose. This work is focused on understanding how tumor vascular permeability is influenced by AuNP-augmented radiation therapy (RT), and how this knowledge can potentially improve the delivery of additional nanoparticle-based chemotherapeutics. We use dual energy (DE) CT to detect accumulation of AuNPs and increased vascular permeability to liposomal iodine (i.e. a surrogate for chemotherapeutics with liposome encapsulation) following RT. We used sarcoma tumors generated in LSL-KrasG12D; p53FL/FL conditional mutant mice. A total of n=37 mice were used in this study. The treated mice were injected with 20 mg AuNP (0.1 ml/25 g mouse) 24 hours before delivery of 5 Gy RT (n=5), 10 Gy RT (n=3) or 20 Gy RT (n=6). The control mice received no AuNP injection and either no RT (n=6), 5 Gy RT (n=3), 10 Gy RT (n=3), 20 Gy RT (n=11). Twenty four hours post-RT, the mice were injected with liposomal iodine (0.3 ml/25 mouse) and imaged with DE-CT three days later. The results suggest that independent of any AuNP usage, RT levels of 10 Gy and 20 Gy increase the permeability of tumor vasculature to liposomal iodine and that the increase in permeability is dose-dependent. We found that the effect of RT on vasculature may already be at its maximum response i.e. saturated at 20 Gy, and therefore the addition of AuNPs had almost no added benefit. Similarly, at 5 Gy RT, our data suggests that there was no effect of AuNP augmentation on tumor vascular permeability. However, by using AuNPs with 10 Gy RT, we observed an increase in the vascular permeability, however this is not yet statistically significant due to the small

  12. Experience of Dual Time Point Brain F-18 FDG PET/CT Imaging in Patients with Infections Disease

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dae Weung; Kim, Chang Guhn; Park, Soon Ah; Jung, Sang Ah [Wonkwang University School of Medicine, Iksan (Korea, Republic of)

    2010-06-15

    Dual time point FDG PET imaging (DTPI) has been considered helpful for discrimination of benign and malignant disease, and staging lymph node status in patients with pulmonary malignancy. However, DTPI for benign disease has been rarely reported, and it may show a better description of metabolic status and extent of benign infection disease than early imaging only. The authors report on the use F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) imaging with additional delayed imaging on a 52-year-old man with sparganosis and a 70-year-old man with tuberculous meningitis. To the best of our knowledge, this is the first report on dual time point PET/CT imaging in patients with cerebral sparganosis and tuberculous meningitis.

  13. Computed Tomography of the Head and Neck Region for Tumor Staging-Comparison of Dual-Source, Dual-Energy and Low-Kilovolt, Single-Energy Acquisitions.

    Science.gov (United States)

    May, Matthias Stefan; Bruegel, Joscha; Brand, Michael; Wiesmueller, Marco; Krauss, Bernhard; Allmendinger, Thomas; Uder, Michael; Wuest, Wolfgang

    2017-09-01

    The aim of this study was to intra-individually compare the image quality obtained by dual-source, dual-energy (DSDE) computed tomography (CT) examinations and different virtual monoenergetic reconstructions to a low single-energy (SE) scan. Third-generation DSDE-CT was performed in 49 patients with histologically proven malignant disease of the head and neck region. Weighted average images (WAIs) and virtual monoenergetic images (VMIs) for low (40 and 60 keV) and high (120 and 190 keV) energies were reconstructed. A second scan aligned to the jaw, covering the oral cavity, was performed for every patient to reduce artifacts caused by dental hardware using a SE-CT protocol with 70-kV tube voltages and matching radiation dose settings. Objective image quality was evaluated by calculating contrast-to-noise ratios. Subjective image quality was evaluated by experienced radiologists. Highest contrast-to-noise ratios for vessel and tumor attenuation were obtained in 40-keV VMI (all P VMI, WAI, and the 70-kV SE examinations. Overall subjective image quality was also highest for 40-keV, but differences to 60-keV VMI, WAI, and 70-kV SE were nonsignificant (all P > 0.05). High kiloelectron volt VMIs reduce metal artifacts with only limited diagnostic impact because of insufficiency in case of severe dental hardware. CTDIvol did not differ significantly between both examination protocols (DSDE: 18.6 mGy; 70-kV SE: 19.4 mGy; P = 0.10). High overall image quality for tumor delineation in head and neck imaging were obtained with 40-keV VMI. However, 70-kV SE examinations are an alternative and modified projections aligned to the jaw are recommended in case of severe artifacts caused by dental hardware.

  14. CT dual-energy decomposition into x-ray signatures ρe and Ze

    Science.gov (United States)

    Martz, Harry E.; Seetho, Issac M.; Champley, Kyle E.; Smith, Jerel A.; Azevedo, Stephen G.

    2016-05-01

    In a recent journal article [IEEE Trans. Nuc. Sci., 63(1), 341-350, 2016], we introduced a novel method that decomposes dual-energy X-ray CT (DECT) data into electron density (ρe) and a new effective-atomic-number called Ze in pursuit of system-independent characterization of materials. The Ze of a material, unlike the traditional Zeff, is defined relative to the actual X-ray absorption properties of the constituent atoms in the material, which are based on published X-ray cross sections. Our DECT method, called SIRZ (System-Independent ρe, Ze), uses a set of well-known reference materials and an understanding of the system spectral response to produce accurate and precise estimates of the X-ray-relevant basis variables (ρe, Ze) regardless of scanner or spectra in diagnostic energy ranges (30 to 200 keV). Potentially, SIRZ can account for and correct spectral changes in a scanner over time and, because the system spectral response is included in the technique, additional beam-hardening correction is not needed. Results show accuracy (<3%) and precision (<2%) values that are much better than prior methods on a wide range of spectra. In this paper, we will describe how to convert DECT system output into (ρe, Ze) features and we present our latest SIRZ results compared with ground truth for a set of materials.

  15. Assessment of vectorial total variation penalties on realistic dual-energy CT data.

    Science.gov (United States)

    Rigie, David S; Sanchez, Adrian A; La Rivière, Patrick J

    2017-04-21

    Vectorial extensions of total variation have recently been developed for regularizing the reconstruction and denoising of multi-channel images, such as those arising in spectral computed tomography. Early studies have focused mainly on simulated, piecewise-constant images whose structure may favor total-variation penalties. In the current manuscript, we apply vectorial total variation to real dual-energy CT data of a whole turkey in order to determine if the same benefits can be observed in more complex images with anatomically realistic textures. We consider the total nuclear variation ([Formula: see text]) as well as another vectorial total variation based on the Frobenius norm ([Formula: see text]) and standard channel-by-channel total variation ([Formula: see text]). We performed a series of 3D TV denoising experiments comparing the three TV variants across a wide range of smoothness parameter settings, optimizing each regularizer according to a very-high-dose 'ground truth' image. Consistent with the simulation studies, we find that both vectorial TV variants achieve a lower error than the channel-by-channel TV and are better able to suppress noise while preserving actual image features. In this real data study, the advantages are subtler than in the previous simulation study, although the [Formula: see text] penalty is found to have clear advantages over either [Formula: see text] or [Formula: see text] when comparing material images formed from linear combinations of the denoised energy images.

  16. Diagnostic image quality of a comprehensive high-pitch dual-spiral cardiothoracic CT protocol in patients with undifferentiated acute chest pain

    Energy Technology Data Exchange (ETDEWEB)

    Bamberg, Fabian, E-mail: fbamberg@med.lmu.de [Department of Clinical Radiology, Ludwig-Maximilians University, Klinikum Grosshadern, Munich (Germany); Marcus, Roy; Sommer, Wieland; Schwarz, Florian; Nikolaou, Konstantin; Becker, Christoph R.; Reiser, Maximilian F.; Johnson, Thorsten R.C. [Department of Clinical Radiology, Ludwig-Maximilians University, Klinikum Grosshadern, Munich (Germany)

    2012-12-15

    Objective: To evaluate diagnostic image quality of high-pitch dual source comprehensive cardiothoracic CT protocol in patients presenting with acute undifferentiated chest pain. Materials and methods: Consecutive symptomatic subjects (n = 51) with undifferentiated acute chest pain underwent ECG-synchronized high-pitch dual-spiral chest CT angiography (Definition Flash, Siemens Medical Solutions, 2 × 100 kVp or 2 × 120 kV if BMI > 30, collimation: 128 × 0.6 mm, pitch: 3.2). Independent investigators determined the image quality of each cardiac and pulmonary vessel segment, measured contrast-to-noise-ratio (CNR), and determined radiation exposure. In addition, the prevalence of CT findings (pulmonary embolism (PE), aortic dissection (AD) and significant coronary stenosis (≥50%)) was determined. Univariate and multivariate analysis were performed to determine the subpopulation with highest diagnostic quality. Results: Among 51 subjects (66% male, average age: 63 ± 15.8), the prevalence of positive CT findings was moderate (overall: 11.7%). Overall, image quality of the pulmonary, aortic and coronary vasculature was good (1.26 ± 0.43 and CNR: 2.52) with an average radiation dose of 3.82 mSv and 3.2% of segments rated non-evaluable. The image quality was lowest in the coronary arteries (p = 0.02), depending on the heart rate (r = 0.52, p < 0.001). In subjects with a heart rate of ≤65 bpm (n = 30) subjective image quality and CNR of the coronary arteries were higher (1.6 ± 0.5 vs. 2.1 ± 0.5, p = 0.03 and 1.21 ± 0.3 vs. 1.02 ± 0.3, p = 0.05) with only 1.5% segments classified as non-evaluable. Conclusion: High-pitch dual-spiral comprehensive cardiothoracic CT provides low radiation exposure with excellent image quality at heart rates ≤65 bpm. In subjects with higher heart rates, image quality of the aortic and pulmonary vasculature remains excellent, while the assessment of the coronary arteries degrades substantially.

  17. Optimization and assessment of quantitative {sup 124}I imaging on a Philips Gemini dual GS PET/CT system

    Energy Technology Data Exchange (ETDEWEB)

    Gregory, Rebecca A.; Hooker, Claire A.; Partridge, Mike; Flux, Glenn D. [Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Joint Department of Physics, Sutton (United Kingdom)

    2009-07-15

    Quantitative {sup 124}I PET imaging is challenging as {sup 124}I has a complex decay scheme. In this study the performance of a Philips Gemini dual GS PET/CT system was optimized and assessed for {sup 124}I. The energy window giving the maximum noise equivalent count rate (NECR) and NEMA 2001-NU2 image quality were measured. The activity concentration (AC) accuracy of images calibrated using factors from {sup 18}F and {sup 124}I decaying source measurements were investigated. The energy window 455-588 keV gave the maximum NECR of 9.67 kcps for 233 MBq. {sup 124}I and {sup 18}F image quality was comparable, although {sup 124}I background variability was increased. The average underestimation in AC in {sup 124}I images was 17.9 {+-} 2.9% for nonuniform background and 14.7 {+-} 2.9% for single scatter simulation (SSS) subtraction scatter correction. At 224 MBq the underestimation was 10.8 {+-} 11.3%, which is comparable to 7.7 {+-} 5.3% for {sup 18}F, but increased with decreasing activity. The best {sup 124}I PET quantitative accuracy was achieved for the optimized energy window, using SSS scatter correction and calibration factors from decaying {sup 124}I source measurements. The quantitative accuracy for {sup 124}I was comparable to that for {sup 18}F at high activities of 224 MBq but diminishing with decreasing activity. Specific corrections for prompt {gamma}-photons may further improve the quantitative accuracy. (orig.)

  18. CT/MRI双模态造影剂的制备和表征%Synthesis and characterization of dual modality contrast agent for CT/MRI imaging

    Institute of Scientific and Technical Information of China (English)

    王月花; 宋丽娜; 丁佳丽; 鲁珊珊; 蒋燕妮; 张宇; 顾宁

    2011-01-01

    Objective: To synthesis a kind of oil- in- water nanoemulsion for dual modal CT/MRI imaging and characterize it. Methods: Using coprecipitation method to synthesis oleic acid coated Fe3O4 nanoparticles, and dispersed them into iodinated oil injection. CT/MRI dual modality contrast agent was prepared on the basis of nanoemulsion formation, which was characterized by TEM, DLS, assembly of nanodroplets under a horizontal magnetic field,CT and MRI. Results : (l) TEM results revealed that the nanoemulsion had a size of 100 nm. DLS study showed the hydrodynamic mean diameter was 81.7 nm, approximately. (2) Placing the nanoemulsion under a horizontal magnetic field showed Fe3O4 nanoparticles existed in the droplets. ( 3 ) CT and MRI measurements showed the CT value was 292. 6 HU ( iodine concentration : 24 mg · ml-1) , and the relaxibility value ( r2) of the nanoemulsion was 65. 7 mmol·L -1 ·s -1. Conclusion : This kind of oil-in-water nanoemulsion enhances prominently CT and MRI contrast, which is expected to become an excellent dual modality contrast agent for CT/MRI imaging.%目的:合成用于CT/MRI双模态造影的水包油型纳米乳液,并对其进行表征.方法:用共沉淀法合成油酸包裹的Fe3O4纳米颗粒,然后将其分散到市售的碘化油注射液中,借助纳米乳液的合成方法合成出CT/MRI双模态造影剂,并用透射电镜(TEM)、动态光散射(DLS)、水平磁场作用下乳滴的组装、CT和MRI等方法进行表征.结果:(1) TEM结果显示,乳滴的直径约为100 nm,DLS测得其水动力尺寸平均为81.7 nm;(2) 将乳液置于水平磁场作用下验证了Fe3O4纳米颗粒确实存在于乳滴内;(3) CT、MRI等分析手段显示了该乳液的CT值为292.6 HU(碘含量为24 mg·ml-1),弛豫率为65.7 mmol·L-1·s-1.结论:CT/MRI双模态造影的水包油型纳米乳液具有良好的CT和MRI造影增强效果,有望成为一种性能优异的CT/MRI双模态造影剂.

  19. Coronary revascularization treatment based on dual-source computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Dikkers, R.; Willems, T.P.; Jonge, G.J. de; Zaag-Loonen, H.J. van der; Ooijen, P.M.A. van; Oudkerk, M. [University of Groningen, Department of Radiology, Groningen (Netherlands); University Medical Center, Groningen (Netherlands); Piers, L.H.; Tio, R.A.; Zijlstra, F. [University of Groningen, Department of Cardiology, Groningen (Netherlands); University Medical Center, Groningen (Netherlands)

    2008-09-15

    Therapy advice based on dual-source computed tomography (DSCT) in comparison with coronary angiography (CAG) was investigated and the results evaluated after 1-year follow-up. Thirty-three consecutive patients (mean age 61.9 years) underwent DSCT and CAG and were evaluated independently. In an expert reading (the ''gold standard''), CAG and DSCT examinations were evaluated simultaneously by an experienced radiologist and cardiologist. Based on the presence of significant stenosis and current guidelines, therapy advice was given by all readers blinded from the results of other readings and clinical information. Patients were treated based on a multidisciplinary team evaluation including all clinical information. In comparison with the gold standard, CAG had a higher specificity (91%) and positive predictive value (PPV) (95%) compared with DSCT (82% and 91%, respectively). DSCT had a higher sensitivity (96%) and negative predictive value (NPV) (89%) compared with CAG (91% and 83%, respectively). The DSCT-based therapy advice did not lead to any patient being denied the revascularization they needed according to the multidisciplinary team evaluation. During follow-up, two patients needed additional revascularization. The high NPV for DSCT for revascularization assessment indicates that DSCT could be safely used to select patients benefiting from medical therapy only. (orig.)

  20. Model-Based Iterative Reconstruction for Dual-Energy X-Ray CT Using a Joint Quadratic Likelihood Model.

    Science.gov (United States)

    Zhang, Ruoqiao; Thibault, Jean-Baptiste; Bouman, Charles A; Sauer, Ken D; Hsieh, Jiang

    2014-01-01

    Dual-energy X-ray CT (DECT) has the potential to improve contrast and reduce artifacts as compared to traditional CT. Moreover, by applying model-based iterative reconstruction (MBIR) to dual-energy data, one might also expect to reduce noise and improve resolution. However, the direct implementation of dual-energy MBIR requires the use of a nonlinear forward model, which increases both complexity and computation. Alternatively, simplified forward models have been used which treat the material-decomposed channels separately, but these approaches do not fully account for the statistical dependencies in the channels. In this paper, we present a method for joint dual-energy MBIR (JDE-MBIR), which simplifies the forward model while still accounting for the complete statistical dependency in the material-decomposed sinogram components. The JDE-MBIR approach works by using a quadratic approximation to the polychromatic log-likelihood and a simple but exact nonnegativity constraint in the image domain. We demonstrate that our method is particularly effective when the DECT system uses fast kVp switching, since in this case the model accounts for the inaccuracy of interpolated sinogram entries. Both phantom and clinical results show that the proposed model produces images that compare favorably in quality to previous decomposition-based methods, including FBP and other statistical iterative approaches.

  1. Dual-energy CT angiography in peripheral arterial occlusive disease - accuracy of maximum intensity projections in clinical routine and subgroup analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kau, Thomas [Klinikum Klagenfurt, General Hospital of Klagenfurt, Institute of Diagnostic and Interventional Radiology, Klagenfurt (Austria); Klinikum Klagenfurt am Worthersee, Radiologie, Klagenfurt (Austria); Eicher, Wolfgang; Reiterer, Christian; Niedermayer, Martin; Rabitsch, Egon; Hausegger, Klaus A. [Klinikum Klagenfurt, General Hospital of Klagenfurt, Institute of Diagnostic and Interventional Radiology, Klagenfurt (Austria); Senft, Birgit [Section of Statistics, Reha Clinic for Mental Health, Klagenfurt (Austria)

    2011-08-15

    To evaluate the accuracy of dual-energy CT angiography (DE-CTA) maximum intensity projections (MIPs) in symptomatic peripheral arterial occlusive disease (PAOD). In 58 patients, DE-CTA of the lower extremities was performed on dual-source CT. In a maximum of 35 arterial segments, severity of the most stenotic lesion was graded (<10%, 10-49% and 50-99% luminal narrowing or occlusion) independently by two radiologists, with DSA serving as the reference standard. In DSA, 52.3% of segments were significantly stenosed or occluded. Agreement of DE-CTA MIPs with DSA was good in the aorto-iliac and femoro-popliteal regions ({kappa} = 0.72; {kappa} = 0.66), moderate in the crural region ({kappa} = 0.55), slight in pedal arteries ({kappa} = 0.10) and very good in bypass segments ({kappa} = 0.81). Accuracy was 88%, 78%, 74%, 55% and 82% for the respective territories and moderate (75%) overall, with good sensitivity (84%) and moderate specificity (67%). Sensitivity and specificity was 82% and 76% in claudicants and 84% and 61% in patients with critical limb ischaemia. While correlating well with DSA above the knee, accuracy of DE-CTA MIPs appeared to be moderate in the calf and largely insufficient in calcified pedal arteries, especially in patients with critical limb ischaemia. (orig.)

  2. Ventilation imaging of the paranasal sinuses using xenon-enhanced dynamic single-energy CT and dual-energy CT: a feasibility study in a nasal cast

    Energy Technology Data Exchange (ETDEWEB)

    Thieme, Sven F.; Helck, Andreas D.; Reiser, Maximilian F.; Johnson, Thorsten R.C. [Ludwig Maximilians University Hospital Munich, Institute for Clinical Radiology, Munich (Germany); Moeller, Winfried; Eickelberg, Oliver [Institute for Lung Biology and Disease (iLBD) and Comprehensive Pneumology Center (CPC), Helmholtz Zentrum Muenchen, Neuherberg, Munich (Germany); Becker, Sven [Ludwig-Maximilians-Universitaet, Department of Otorhinolaryngology - Head and Neck Surgery, Munich (Germany); Schuschnig, Uwe [Pari Pharma GmbH, Graefelfing (Germany)

    2012-10-15

    To show the feasibility of dual-energy CT (DECT) and dynamic CT for ventilation imaging of the paranasal sinuses in a nasal cast. In a first trial, xenon gas was administered to a nasal cast with a laminar flow of 7 L/min. Dynamic CT acquisitions of the nasal cavity and the sinuses were performed. This procedure was repeated with pulsating xenon flow. Local xenon concentrations in the different compartments of the model were determined on the basis of the enhancement levels. In a second trial, DECT measurements were performed both during laminar and pulsating xenon administration and the xenon concentrations were quantified directly. Neither with dynamic CT nor DECT could xenon-related enhancement be detected in the sinuses during laminar airflow. Using pulsating flow, dynamic imaging showed a xenon wash-in and wash-out in the sinuses that followed a mono-exponential function with time constants of a few seconds. Accordingly, DECT revealed xenon enhancement in the sinuses only after pulsating xenon administration. The feasibility of xenon-enhanced DECT for ventilation imaging was proven in a nasal cast. The superiority of pulsating gas flow for the administration of gas or aerosolised drugs to the paranasal sinuses was demonstrated. (orig.)

  3. Assessing Cardiac Injury in Mice With Dual Energy-MicroCT, 4D-MicroCT, and MicroSPECT Imaging After Partial Heart Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chang-Lung; Min, Hooney [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Befera, Nicholas; Clark, Darin; Qi, Yi [Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, North Carolina (United States); Das, Shiva [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Johnson, G. Allan; Badea, Cristian T. [Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, North Carolina (United States); Kirsch, David G., E-mail: david.kirsch@duke.edu [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina (United States)

    2014-03-01

    Purpose: To develop a mouse model of cardiac injury after partial heart irradiation (PHI) and to test whether dual energy (DE)-microCT and 4-dimensional (4D)-microCT can be used to assess cardiac injury after PHI to complement myocardial perfusion imaging using micro-single photon emission computed tomography (SPECT). Methods and Materials: To study cardiac injury from tangent field irradiation in mice, we used a small-field biological irradiator to deliver a single dose of 12 Gy x-rays to approximately one-third of the left ventricle (LV) of Tie2Cre; p53{sup FL/+} and Tie2Cre; p53{sup FL/−} mice, where 1 or both alleles of p53 are deleted in endothelial cells. Four and 8 weeks after irradiation, mice were injected with gold and iodinated nanoparticle-based contrast agents, and imaged with DE-microCT and 4D-microCT to evaluate myocardial vascular permeability and cardiac function, respectively. Additionally, the same mice were imaged with microSPECT to assess myocardial perfusion. Results: After PHI with tangent fields, DE-microCT scans showed a time-dependent increase in accumulation of gold nanoparticles (AuNp) in the myocardium of Tie2Cre; p53{sup FL/−} mice. In Tie2Cre; p53{sup FL/−} mice, extravasation of AuNp was observed within the irradiated LV, whereas in the myocardium of Tie2Cre; p53{sup FL/+} mice, AuNp were restricted to blood vessels. In addition, data from DE-microCT and microSPECT showed a linear correlation (R{sup 2} = 0.97) between the fraction of the LV that accumulated AuNp and the fraction of LV with a perfusion defect. Furthermore, 4D-microCT scans demonstrated that PHI caused a markedly decreased ejection fraction, and higher end-diastolic and end-systolic volumes, to develop in Tie2Cre; p53{sup FL/−} mice, which were associated with compensatory cardiac hypertrophy of the heart that was not irradiated. Conclusions: Our results show that DE-microCT and 4D-microCT with nanoparticle-based contrast agents are novel imaging approaches

  4. A Prospective Comparative Study of Parathyroid Dual-Phase Scintigraphy, Dual-Isotope Subtraction Scintigraphy, 4D-CT, and Ultrasonography in Primary Hyperparathyroidism

    DEFF Research Database (Denmark)

    Krakauer, Martin; Wieslander, Bente; Myschetzky, Peter Sand

    2016-01-01

    PURPOSE: Preoperative localization of the diseased parathyroid gland(s) in primary hyperparathyroidism allows for minimally invasive surgery. This study was designed to establish the optimal first-line preoperative imaging modality. PATIENTS AND METHODS: Ninety-one patients were studied...... standard. RESULTS: Ninety-seven hyperfunctioning parathyroid glands (HPGs) were identified by the reference standard. Sensitivity and specificity for subtraction PS, dual-phase PS, 4D-CT, and US were 93%, 65%, 58%, and 57% as well as 99%, 99.6%, 86%, and 95%, respectively. Interrater agreement...

  5. Dual-isotope SPECT/CT impact on hospitalized patients with suspected diabetic foot infection: saving limbs, lives, and resources.

    Science.gov (United States)

    Heiba, Sherif; Kolker, Dov; Ong, Leonard; Sharma, Shalini; Travis, Arlene; Teodorescu, Victoria; Ellozy, Sharif; Kostakoglu, Lale; Savitch, Ina; Machac, Josef

    2013-09-01

    Foot ulcer with suspected infection is one of the most common reasons for hospitalization and a major factor contributing to morbidity and high healthcare-related expenses among diabetic patients. Many patients will require amputation; however, major amputation is associated with an alarmingly high 5-year mortality rate. In this study, we assess the diagnosis and management of suspected foot infection in diabetic patients using dual-isotope (DI) single-photon emission computed tomography/computed tomography (SPECT/CT) compared with conventional imaging. The diagnostic accuracy in and management of 227 patients who had undergone DI SPECT/CT was compared with that of 232 similar patients who had undergone conventional imaging including plain radiography, CT, planar bone scanning, planar indium-111 white blood cell scanning, and MRI. The duration of hospitalization was additionally compared between these two groups of patients after excluding patients with other active comorbidities. Soft-tissue infection, osteomyelitis with or without soft-tissue infection, and other bony pathologies were more accurately and confidently identified with DI SPECT/CT than with conventional imaging. DI SPECT/CT use was associated with significantly fewer major amputations and more selective bony resection as well as with shorter duration of hospitalization when compared with conventional imaging. In this large population of diabetic patients with suspected foot infection DI SPECT/CT was more accurate in diagnosing and localizing infection compared with conventional imaging. In addition, DI SPECT/CT provided clear guidance and promoted many limb salvage procedures. Of equal importance to health economics, DI SPECT/CT use was associated with considerably reduced length of hospitalization compared with conventional imaging.

  6. Quantitative analysis of the dual-energy CT virtual spectral curve for focal liver lesions characterization

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qi, E-mail: wq20@hotmail.com; Shi, Gaofeng, E-mail: gaofengs62@sina.com; Qi, Xiaohui, E-mail: qixiaohui1984@163.com; Fan, Xueli, E-mail: 407849960@qq.com; Wang, Lijia, E-mail: 893197597@qq.com

    2014-10-15

    Highlights: • We establish a feasible method using the virtual spectral curves (VSC) to differentiate focal liver lesions using DECT. • Our study shows the slope of the VSC can be used to differentiate between hemangioma, HCC, metastasis and cyst. • Importantly, the diagnostic specificities associated with using the slope to diagnose both hemangioma and cysts were 100%. - Abstract: Objective: To assess the usefulness of the spectral curve slope of dual-energy CT (DECT) for differentiating between hepatocellular carcinoma (HCC), hepatic metastasis, hemangioma (HH) and cysts. Methods: In total, 121 patients were imaged in the portal venous phase using dual-energy mode. Of these patients, 23 patients had HH, 28 patients had HCC, 40 patients had metastases and 30 patients had simple cysts. The spectral curves of the hepatic lesions were derived from the 40–190 keV levels of virtual monochromatic spectral imaging. The spectral curve slopes were calculated from 40 to 110 keV. The slopes were compared using the Kruskal–Wallis test. Receiver operating characteristic curves (ROC) were used to determine the optimal cut-off value of the slope of the spectral curve to differentiate between the lesions. Results: The spectral curves of the four lesion types had different baseline levels. The HH baseline level was the highest followed by HCC, metastases and cysts. The slopes of the spectral curves of HH, HCC, metastases and cysts were 3.81 ± 1.19, 1.49 ± 0.57, 1.06 ± 0.76 and 0.13 ± 0.17, respectively. These values were significantly different (P < 0.008). Based on ROC analysis, the respective diagnostic sensitivity and specificity were 87% and 100% for hemangioma (cut-off value ≥ 2.988), 82.1% and 65.9% for HCC (cut-off value 1.167–2.998), 65.9% and 59% for metastasis (cut-off value 0.133–1.167) and 44.4% and 100% for cysts (cut-off value ≤ 0.133). Conclusion: Quantitative analysis of the DECT spectral curve in the portal venous phase can be used to

  7. DualSPHysics: Open-source parallel CFD solver based on Smoothed Particle Hydrodynamics (SPH)

    Science.gov (United States)

    Crespo, A. J. C.; Domínguez, J. M.; Rogers, B. D.; Gómez-Gesteira, M.; Longshaw, S.; Canelas, R.; Vacondio, R.; Barreiro, A.; García-Feal, O.

    2015-02-01

    DualSPHysics is a hardware accelerated Smoothed Particle Hydrodynamics code developed to solve free-surface flow problems. DualSPHysics is an open-source code developed and released under the terms of GNU General Public License (GPLv3). Along with the source code, a complete documentation that makes easy the compilation and execution of the source files is also distributed. The code has been shown to be efficient and reliable. The parallel power computing of Graphics Computing Units (GPUs) is used to accelerate DualSPHysics by up to two orders of magnitude compared to the performance of the serial version.

  8. Iterative reconstruction for dual energy CT with an average image-induced nonlocal means regularization

    Science.gov (United States)

    Zhang, Houjin; Zeng, Dong; Lin, Jiahui; Zhang, Hao; Bian, Zhaoying; Huang, Jing; Gao, Yuanyuan; Zhang, Shanli; Zhang, Hua; Feng, Qianjin; Liang, Zhengrong; Chen, Wufan; Ma, Jianhua

    2017-07-01

    Reducing radiation dose in dual energy computed tomography (DECT) is highly desirable but it may lead to excessive noise in the filtered backprojection (FBP) reconstructed DECT images, which can inevitably increase the diagnostic uncertainty. To obtain clinically acceptable DECT images from low-mAs acquisitions, in this work we develop a novel scheme based on measurement of DECT data. In this scheme, inspired by the success of edge-preserving non-local means (NLM) filtering in CT imaging and the intrinsic characteristics underlying DECT images, i.e. global correlation and non-local similarity, an averaged image induced NLM-based (aviNLM) regularization is incorporated into the penalized weighted least-squares (PWLS) framework. Specifically, the presented NLM-based regularization is designed by averaging the acquired DECT images, which takes the image similarity within the two energies into consideration. In addition, the weighted least-squares term takes into account DECT data-dependent variance. For simplicity, the presented scheme was termed as ‘PWLS-aviNLM’. The performance of the presented PWLS-aviNLM algorithm was validated and evaluated on digital phantom, physical phantom and patient data. The extensive experiments validated that the presented PWLS-aviNLM algorithm outperforms the FBP, PWLS-TV and PWLS-NLM algorithms quantitatively. More importantly, it delivers the best qualitative results with the finest details and the fewest noise-induced artifacts, due to the aviNLM regularization learned from DECT images. This study demonstrated the feasibility and efficacy of the presented PWLS-aviNLM algorithm to improve the DECT reconstruction and resulting material decomposition.

  9. Deep learning for electronic cleansing in dual-energy CT colonography

    Science.gov (United States)

    Tachibana, Rie; Näppi, Janne J.; Hironakaa, Toru; Kim, Se Hyung; Yoshida, Hiroyuki

    2016-03-01

    The purpose of this study was to develop a novel deep-learning-based electronic cleansing (EC) method for dual-energy CT colonography (DE-CTC). In this method, an ensemble of deep convolutional neural networks (DCNNs) is used to classify each voxel of DE-CTC image volumes into one of five multi-material (MUMA) classes: luminal air, soft tissue, tagged fecal material, or a partial-volume boundary between air and tagging or that of soft tissue and tagging. Each DCNN acts as a voxel classifier. At each voxel, a region-of-interest (ROI) centered at the voxel is extracted. After mapping the pixels of the ROI to the input layer of a DCNN, a series of convolutional and max-pooling layers is used to extract features with increasing levels of abstraction. The output layer produces the probabilities at which the input voxel belongs to each of the five MUMA classes. To develop an ensemble of DCNNs, we trained multiple DCNNs based on multi-spectral image volumes derived from the DE-CTC images, including material decomposition images and virtual monochromatic images. The outputs of these DCNNs were then combined by means of a meta-classifier for precise classification of the voxels. Finally, the electronically cleansed CTC images were generated by removing regions that were classified as other than soft tissue, followed by colon surface reconstruction. Preliminary results based on 184,320 images sampled from 30 clinical CTC cases showed a higher accuracy in labeling these classes than that of our previous machine-learning methods, indicating that deep-learning-based multi-spectral EC can accurately remove residual fecal materials from CTC images without generating major EC artifacts.

  10. The feasibility of dual-energy CT in differentiation of vertebral compression fractures

    Science.gov (United States)

    Karaca, Leyla; Yuceler, Zeynep; Çakır, Murteza; Sade, Recep; Calıkoglu, Cagatay; Ogul, Hayri; Bayrakturan, U.Gulsum

    2016-01-01

    Objective: To prospectively evaluate the ability of dual-energy CT (DECT), compared with MRI, to identify vertebral compression fractures in acute trauma patients. Methods: This institutional review board-approved study included 23 consecutive patients with 32 vertebral fractures who underwent both DECT and MRI of the spine between February 2014 and September 2014. A total of 209 vertebrae were evaluated for the presence of abnormal bone marrow attenuation on DECT and signal on MRI by five experienced radiologists. The specificity, sensitivity, predictive values and intraobserver and interobserver agreements were calculated. Results: MRI revealed a total of 47 vertebrae (22.4% of all vertebrae) and DECT revealed 44 vertebrae (21.0% of all vertebrae) with oedema. Using MRI as the reference standard, DECT had sensitivity, specificity, positive-predictive value, negative-predictive value and accuracy of 89.3, 98.7, 95.4, 96.9 and 96.6%, respectively. With respect to establishing the presence of oedema, the interobserver agreement was almost perfect (k = 0.82), and the intraobserver agreement was substantial (k = 0.80). Conclusion: Compared with MRI, DECT can provide an accurate demonstration of acute vertebral fractures and can be used as an alternative imaging modality for the assessment of vertebral fractures in patients with contraindications for MRI. Advances in knowledge: Distinguishing of acute and chronic vertebral compression fracture is important for treatment choices. DECT is very fast compared with MRI and is an alternative imaging modality for the assessment of vertebral fractures in patients with contraindications for MRI. PMID:26537691

  11. Dual Z-Source Inverter With Three-Level Reduced Common-Mode Switching

    DEFF Research Database (Denmark)

    Gao, Feng; Loh, Poh Chiang; Blaabjerg, Frede;

    2007-01-01

    . Modulationwise, the dual inverter can be controlled using a carefully designed carrier-based pulsewidth-modulation (PWM) scheme that will always ensure balanced voltage boosting of the Z-source network while simultaneously achieving reduced common-mode switching. Because of the omission of dead-time delays...... in the dual-inverter PWM scheme, its switched common-mode voltage can be completely eliminated, unlike in traditional inverters, where narrow common-mode spikes are still generated. Under semiconductor failure conditions, the presented PWM schemes can easily be modified to allow the inverter to operate......This paper presents the design of a dual Z-source inverter that can be used with either a single dc source or two isolated dc sources. Unlike traditional inverters, the integration of a properly designed Z-source network and semiconductor switches to the proposed dual inverter allows buck...

  12. US-CT 3D dual imaging by mutual display of the same sections for depicting minor changes in hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Hiroyuki, E-mail: fukuhiro1962@hotmail.com [International HIFU Center, Sanmu Medical Center Hospital, Naruto 167, Sanbu-shi, Chiba 289-1326 (Japan); Ito, Ryu; Ohto, Masao; Sakamoto, Akio [International HIFU Center, Sanmu Medical Center Hospital, Naruto 167, Sanbu-shi, Chiba 289-1326 (Japan); Otsuka, Masayuki; Togawa, Akira; Miyazaki, Masaru [Department of General Surgery, Graduate School of Medicine, Chiba University, Inohana 1-8-1, Chuo-ku, Chiba-shi, Chiba 260-0856 (Japan); Yamagata, Hitoshi [Toshiba Medical Systems Corporation, Otawara 324-0036 (Japan)

    2012-09-15

    The purpose of this study was to evaluate the usefulness of ultrasound-computed tomography (US-CT) 3D dual imaging for the detection of small extranodular growths of hepatocellular carcinoma (HCC). The clinical and pathological profiles of 10 patients with single nodular type HCC with extranodular growth (extranodular growth) who underwent a hepatectomy were evaluated using two-dimensional (2D) ultrasonography (US), three-dimensional (3D) US, 3D computed tomography (CT) and 3D US-CT dual images. Raw 3D data was converted to DICOM (Digital Imaging and Communication in Medicine) data using Echo to CT (Toshiba Medical Systems Corp., Tokyo, Japan), and the 3D DICOM data was directly transferred to the image analysis system (ZioM900, ZIOSOFT Inc., Tokyo, Japan). By inputting the angle number (x, y, z) of the 3D CT volume data into the ZioM900, multiplanar reconstruction (MPR) images of the 3D CT data were displayed in a manner such that they resembled the conventional US images. Eleven extranodular growths were detected pathologically in 10 cases. 2D US was capable of depicting only 2 of the 11 extranodular growths. 3D CT was capable of depicting 4 of the 11 extranodular growths. On the other hand, 3D US was capable of depicting 10 of the 11 extranodular growths, and 3D US-CT dual images, which enable the dual analysis of the CT and US planes, revealed all 11 extranodular growths. In conclusion, US-CT 3D dual imaging may be useful for the detection of small extranodular growths.

  13. A dual tracer (68)Ga-DOTANOC PET/CT and (18)F-FDG PET/CT pilot study for detection of cardiac sarcoidosis.

    Science.gov (United States)

    Gormsen, Lars C; Haraldsen, Ate; Kramer, Stine; Dias, Andre H; Kim, Won Yong; Borghammer, Per

    2016-12-01

    Cardiac sarcoidosis (CS) is a potentially fatal condition lacking a single test with acceptable diagnostic accuracy. (18)F-FDG PET/CT has emerged as a promising imaging modality, but is challenged by physiological myocardial glucose uptake. An alternative tracer, (68)Ga-DOTANOC, binds to somatostatin receptors on inflammatory cells in sarcoid granulomas. We therefore aimed to conduct a proof-of-concept study using (68)Ga-DOTANOC to diagnose CS. In addition, we compared diagnostic accuracy and inter-observer variability of (68)Ga-DOTANOC vs. (18)F-FDG PET/CT. Nineteen patients (seven female) with suspected CS were prospectively recruited and dual tracer scanned within 7 days. PET images were reviewed by four expert readers for signs of CS and compared to the reference standard (Japanese ministry of Health and Welfare CS criteria). CS was diagnosed in 3/19 patients. By consensus, 11/19 (18)F-FDG scans and 0/19 (68)Ga-DOTANOC scans were rated as inconclusive. The sensitivity of (18)F-FDG PET for diagnosing CS was 33 %, specificity was 88 %, PPV was 33 %, NPV was 88 %, and diagnostic accuracy was 79 %. For (68)Ga-DOTANOC, accuracy was 100 %. Inter-observer agreement was poor for (18)F-FDG PET (Fleiss' combined kappa 0.27, NS) and significantly better for (68)Ga-DOTANOC (Fleiss' combined kappa 0.46, p = 0.001). Despite prolonged pre-scan fasting, a large proportion of (18)F-FDG PET/CT images were rated as inconclusive, resulting in low agreement among reviewers and correspondingly poor diagnostic accuracy. By contrast, (68)Ga-DOTANOC PET/CT had excellent diagnostic accuracy with the caveat that inter-observer variability was still significant. Nevertheless, (68)Ga-DOTANOC PET/CT looks very promising as an alternative CS PET tracer. Current Controlled Trials NCT01729169 .

  14. Cardiac amyloidosis imaged by dual-source computed tomography.

    Science.gov (United States)

    Marwan, Mohamed; Pflederer, Tobias; Ropers, Dieter; Schmid, Michael; Wasmeier, Gerald; Söder, Stephan; Daniel, Werner G; Achenbach, Stephan

    2008-11-01

    The ability of contrast-enhanced CT to detect "late enhancement" in a fashion similar to magnetic resonance imaging has been reported previously. Typical myocardial distribution patterns of "late enhancement" have been described for MRI. The same patterns can be observed in CT imaging, albeit at a lower signal to noise ratio. We report a case of cardiac amyloidosis with a typical pattern of subendocardial, circumferential late enhancement in all four cardiac chambers.

  15. Dual-energy-CT of hypervascular liver lesions in patients with HCC: investigation of image quality and sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Altenbernd, Jens [University of Duisburg-Essen, Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen (Germany); University Hospital Essen, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany); Heusner, Till A.; Ringelstein, Adrian; Ladd, Susanne C.; Forsting, Michael; Antoch, Gerald [University of Duisburg-Essen, Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen (Germany)

    2011-04-15

    To investigate dual-energy CT of hypervascular liver lesions in patients with HCC. Forty patients with hepatocellular carcinomas were investigated with abdominal dual-energy CT. In each patient unenhanced and contrast-enhanced imaging with arterial und portovenous delay were performed. Hypervascular lesions were documented on arterial phase 80-kVp images, 140-kVp images, and the averaged arterial images by two radiologists. Subjective image quality (5-point scale, from 5 [excellent] to 1 [not interpretable]) was rated on all images. The mean number of hypervascular HCC lesions detected was 3.37 {+-} 1.28 on 80-kVp images (p < 0.05), 1.43 {+-} 1.13 on 140-kVp images (p < 0.05), and 2.57 {+-} 1.2 on averaged images. The image quality was 0.3 {+-} 0.5 for 80-kVp (p < 0.05), 1.6 {+-} 0.5 for 140-kVp (p < 0.05) and 3.2 {+-} 0.4 for the averaged images. Low-kVp images of dual-energy datasets are more sensitive in detecting hypervascular liver lesions. However, this increase in sensitivity goes along with a decrease in the subjective image quality of low-kVp images. (orig.)

  16. A new method to measure electron density and effective atomic number using dual-energy CT images

    Science.gov (United States)

    Ramos Garcia, Luis Isaac; Pérez Azorin, José Fernando; Almansa, Julio F.

    2016-01-01

    The purpose of this work is to present a new method to extract the electron density ({ρ\\text{e}} ) and the effective atomic number (Z eff) from dual-energy CT images, based on a Karhunen-Loeve expansion (KLE) of the atomic cross section per electron. This method was used to calibrate a Siemens Definition CT using the CIRS phantom. The predicted electron density and effective atomic number using 80 kVp and 140 kVp were compared with a calibration phantom and an independent set of samples. The mean absolute deviations between the theoretical and calculated values for all the samples were 1.7 %  ±  0.1 % for {ρ\\text{e}} and 4.1 %  ±  0.3 % for Z eff. Finally, these results were compared with other stoichiometric method. The application of the KLE to represent the atomic cross section per electron is a promising method for calculating {ρ\\text{e}} and Z eff using dual-energy CT images.

  17. Measurement of opening and closing angles of aortic valve prostheses in vivo using dual-source computed tomography: Comparison with those of manufacturers' in 10 different types

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Young Joo; Kim, Young Jin; Hong, Yoo Jin; Lee, Hye Jeong; Hur, Jin; Im, Dong Jin; Kim, Yun Jung; Choi, Byoung Wook [Dept. of Radiology, Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2015-10-15

    The aims of this study were to compare opening and closing angles of normally functioning mechanical aortic valves measured on dual-source computed tomography (CT) with the manufacturers' values and to compare CT-measured opening angles according to valve function. A total of 140 patients with 10 different types of mechanical aortic valves, who underwent dual-source cardiac CT, were included. Opening and closing angles were measured on CT images. Agreement between angles in normally functioning valves and the manufacturer values was assessed using the interclass coefficient and the Bland-Altman method. CT-measured opening angles were compared between normal functioning valves and suspected dysfunctioning valves. The CT-measured opening angles of normally functioning valves and manufacturers' values showed excellent agreement for seven valve types (intraclass coefficient [ICC], 0.977; 95% confidence interval [CI], 0.962-0.987). The mean differences in opening angles between the CT measurements and the manufacturers' values were 1.2° in seven types of valves, 11.0° in On-X valves, and 15.5° in ATS valves. The manufacturers' closing angles and those measured by CT showed excellent agreement for all valve types (ICC, 0.953; 95% CI, 0.920-0.972). Among valves with suspected dysfunction, those with limitation of motion (LOM) and an increased pressure gradient (PG) had smaller opening angles than those with LOM only (p < 0.05). Dual-source cardiac CT accurately measures opening and closing angles in most types of mechanical aortic valves, compared with the manufacturers' values. Opening angles on CT differ according to the type of valve dysfunction and a decreased opening angle may suggest an elevated PG.

  18. A model for quantitative correction of coronary calcium scores on multidetector, dual source, and electron beam computed tomography for influences of linear motion, calcification density, and temporal resolution : A cardiac phantom study

    NARCIS (Netherlands)

    Greuter, M. J. W.; Groen, J. M.; Nicolai, L. J.; Dijkstra, H.; Oudkerk, M.

    2009-01-01

    Purpose: The objective of this study is to quantify the influence of linear motion, calcification density, and temporal resolution on coronary calcium determination using multidetector computed tomography (MDCT), dual source CT (DSCT), and electron beam tomography (EBT) and to find a quantitative me

  19. Added value of lung perfused blood volume images using dual-energy CT for assessment of acute pulmonary embolism

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Munemasa, E-mail: radokada@yamaguchi-u.ac.jp [Department of Radiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan); Kunihiro, Yoshie [Department of Radiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan); Nakashima, Yoshiteru [Department of Radiology, Yamaguchi Grand Medical Center, Oosaki 77, Hofu, Yamaguchi 747-8511 (Japan); Nomura, Takafumi [Department of Radiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan); Kudomi, Shohei; Yonezawa, Teppei [Department of Radiology, Yamaguchi University Hospital, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan); Suga, Kazuyoshi [Department of Radiology, St. Hills Hospital, Imamurakita 3-7-18, Ube, Yamaguchi 755-0155 (Japan); Matsunaga, Naofumi [Department of Radiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan)

    2015-01-15

    Purpose: To investigate the added value of lung perfused blood volume (LPBV) using dual-energy CT for the evaluation of intrapulmonary clot (IPC) in patients suspected of having acute pulmonary embolism (PE). Materials and methods: Institutional review board approval was obtained for this retrospective study. Eighty-three patients suspected of having PE who underwent CT pulmonary angiography (CTPA) using a dual-energy technique were enrolled in this study. Two radiologists who were blinded retrospectively and independently reviewed CTPA images alone and the combined images with color-coded LPBV over a 4-week interval, and two separate sessions were performed with a one-month interval. Inter- and intraobserver variability and diagnostic accuracy were evaluated for each reviewer with receiver operating characteristic (ROC) curve analysis. Results: Values for inter- and intraobserver agreement, respectively, were better for CTPA combined with LPBV (ICC = 0.847 and 0.937) than CTPA alone (ICC = 0.748 and 0.861). For both readers, diagnostic accuracy (area under the ROC curve [A{sub z}]) were also superior, when CTPA alone (A{sub z} = 0.888 [reader 1] and 0.912 [reader 2]) was compared with that after the combination with LPBV images (A{sub z} = 0.966 [reader 1] and 0.959 [reader 2]) (p < 0.001). However, A{sub z} values of both images might not have significant difference in statistics, because A{sub z} value of CTPA alone was high and 95% confidence intervals overlapped in both images. Conclusion: Addition of dual-energy perfusion CT to CTPA improves detection of peripheral IPCs with better interobserver agreement.

  20. Contrast volume reduction using third generation dual source computed tomography for the evaluation of patients prior to transcatheter aortic valve implantation

    Energy Technology Data Exchange (ETDEWEB)

    Bittner, Daniel O. [University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuernberg (FAU), Department of Internal Medicine 2 (Cardiology), Erlangen (Germany); Harvard Medical School, Cardiac MR PET CT Program, Massachusetts General Hospital, Boston, MA (United States); Arnold, Martin; Klinghammer, Lutz; Schuhbaeck, Annika; Hell, Michaela M.; Muschiol, Gerd; Gauss, Soeren; Achenbach, Stephan; Marwan, Mohamed [University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuernberg (FAU), Department of Internal Medicine 2 (Cardiology), Erlangen (Germany); Lell, Michael; Uder, Michael [University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuernberg (FAU), Department of Radiology, Erlangen (Germany); Hoffmann, Udo [Harvard Medical School, Cardiac MR PET CT Program, Massachusetts General Hospital, Boston, MA (United States)

    2016-12-15

    Chronic renal failure is common in patients referred for transcatheter aortic valve implantation (TAVI). CT angiography is recommended and provides crucial information prior to TAVI. We evaluated the feasibility of a reduced contrast volume protocol for pre-procedural CT imaging. Forty consecutive patients were examined with prospectively ECG-triggered high-pitch spiral acquisition using a novel third-generation dual-source CT system; 38 ml contrast agent was used. Image quality was graded on a visual scale (1-4). Contrast attenuation was measured at the level of the aortic root and at the iliac bifurcation. Mean patient age was 82 ± 6 years (23 males; 58 %). Mean attenuation/average image quality was 285 ± 60 HU/1.5 at the aortic annulus compared to 289 ± 74 HU/1.8 at the iliac bifurcation (p = 0.77/p = 0.29). Mean estimated effective radiation dose was 2.9 ± 0.3 mSv. A repeat acquisition was necessary in one patient due to image quality. Out of the 35 patients who underwent TAVI, 31 (89 %) patients had no or mild aortic regurgitation. Thirty-two (91 %) patients were discharged successfully. Pre-procedural CTA with a total of 38 ml contrast volume is feasible and clinically useful, using third-generation dual-source CT, allowing comprehensive imaging for procedural success. (orig.)

  1. Gold nanoshelled liquid perfluorocarbon nanocapsules for combined dual modal ultrasound/CT imaging and photothermal therapy of cancer.

    Science.gov (United States)

    Ke, Hengte; Yue, Xiuli; Wang, Jinrui; Xing, Sen; Zhang, Qian; Dai, Zhifei; Tian, Jie; Wang, Shumin; Jin, Yushen

    2014-03-26

    The integration of multimodal contrast-enhanced diagnostic imaging and therapeutic capabilities could utilize imaging guided therapy to plan the treatment strategy based on the diagnostic results and to guide/monitor the therapeutic procedures. Herein, gold nanoshelled perfluorooctylbromide (PFOB) nanocapsules with PEGylation (PGsP NCs) are constructed by oil-in-water emulsion method to form polymeric PFOB nanocapsules, followed by the formation of PEGylated gold nanoshell on the surface. PGsP NCs could not only provide excellent contrast enhancement for dual modal ultrasound and CT imaging in vitro and in vivo, but also serve as efficient photoabsorbers for photothermal ablation of tumors on xenografted nude mouse model. To our best knowledge, this is the first report of gold nanoshell serving as both CT contrast agents and photoabsorbers for photothermal therapy. The novel multifunctional nanomedicine would be of great value to offer more comprehensive diagnostic information to guide more accurate and effective cancer therapy.

  2. Direct visualization of regions with lowered bone mineral density in dual-energy CT images of vertebrae

    Science.gov (United States)

    Wesarg, Stefan; Erdt, Marius; Kafchitsas, Konstantinos; Khan, M. Fawad

    2011-03-01

    Dual-energy CT allows for a better material differentiation than conventional CT. For the purpose of osteoporosis diagnosis, a detection of regions with lowered bone mineral density (BMD) is of high clinical interest. Based on an existing biophysical model of the trabecular bone in vertebrae a new method for directly highlighting those low density regions in the image data has been developed. For this, we combine image data acquired at 80 kV and 140 kV with information about the BMD range in different vertebrae and derive a method for computing a color enhanced image which clearly indicates low density regions. An evaluation of our method which compares it with a quantitative method for BMD assessment shows a very good correspondence between both methods. The strength of our method lies in its simplicity and speed.

  3. Tissue decomposition from dual energy CT data for MC based dose calculation in particle therapy

    Energy Technology Data Exchange (ETDEWEB)

    Hünemohr, Nora, E-mail: n.huenemohr@dkfz.de; Greilich, Steffen [Medical Physics in Radiation Oncology, German Cancer Research Center, 69120 Heidelberg (Germany); Paganetti, Harald; Seco, Joao [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114 (United States); Jäkel, Oliver [Medical Physics in Radiation Oncology, German Cancer Research Center, 69120 Heidelberg, Germany and Department of Radiation Oncology and Radiation Therapy, University Hospital of Heidelberg, 69120 Heidelberg (Germany)

    2014-06-15

    Purpose: The authors describe a novel method of predicting mass density and elemental mass fractions of tissues from dual energy CT (DECT) data for Monte Carlo (MC) based dose planning. Methods: The relative electron density ϱ{sub e} and effective atomic number Z{sub eff} are calculated for 71 tabulated tissue compositions. For MC simulations, the mass density is derived via one linear fit in the ϱ{sub e} that covers the entire range of tissue compositions (except lung tissue). Elemental mass fractions are predicted from the ϱ{sub e} and the Z{sub eff} in combination. Since particle therapy dose planning and verification is especially sensitive to accurate material assignment, differences to the ground truth are further analyzed for mass density, I-value predictions, and stopping power ratios (SPR) for ions. Dose studies with monoenergetic proton and carbon ions in 12 tissues which showed the largest differences of single energy CT (SECT) to DECT are presented with respect to range uncertainties. The standard approach (SECT) and the new DECT approach are compared to reference Bragg peak positions. Results: Mean deviations to ground truth in mass density predictions could be reduced for soft tissue from (0.5±0.6)% (SECT) to (0.2±0.2)% with the DECT method. Maximum SPR deviations could be reduced significantly for soft tissue from 3.1% (SECT) to 0.7% (DECT) and for bone tissue from 0.8% to 0.1%. MeanI-value deviations could be reduced for soft tissue from (1.1±1.4%, SECT) to (0.4±0.3%) with the presented method. Predictions of elemental composition were improved for every element. Mean and maximum deviations from ground truth of all elemental mass fractions could be reduced by at least a half with DECT compared to SECT (except soft tissue hydrogen and nitrogen where the reduction was slightly smaller). The carbon and oxygen mass fraction predictions profit especially from the DECT information. Dose studies showed that most of the 12 selected tissues would

  4. Peering through the glare: using dual-energy CT to overcome the problem of metal artefacts in bone radiology

    Energy Technology Data Exchange (ETDEWEB)

    Coupal, Tyler M. [McMaster University, Michael G. DeGroote School of Medicine, Hamilton, ON (Canada); Mallinson, Paul I.; McLaughlin, Patrick; Nicolaou, Savvas; Munk, Peter L.; Ouellette, Hugue [Vancouver General Hospital, Radiology Department, Vancouver, BC (Canada)

    2014-05-15

    Imaging of patients with large metal implants remains one of the most difficult endeavours for radiologists. This article reviews the theory of dual-energy CT (DECT) and its ability to reduce metal artefact, thus enhancing the diagnostic value of musculoskeletal imaging. The strengths, weaknesses, and alternative applications of DECT, as well as areas requiring further research, will also be reviewed. Currently, DECT stands as the frontier for metal artefact reduction in musculoskeletal imaging. DECT requires no additional radiation and provides significantly enhanced image acquisition. When considered along with its other capabilities, DECT is a promising new tool for musculoskeletal and trauma radiologists. (orig.)

  5. Determination of liquid's molecular interference function based on X-ray diffraction and dual-energy CT in security screening.

    Science.gov (United States)

    Zhang, Li; YangDai, Tianyi

    2016-08-01

    A method for deriving the molecular interference function (MIF) of an unknown liquid for security screening is presented. Based on the effective atomic number reconstructed from dual-energy computed tomography (CT), equivalent molecular formula of the liquid is estimated. After a series of optimizations, the MIF and a new effective atomic number are finally obtained from the X-ray diffraction (XRD) profile. The proposed method generates more accurate results with less sensitivity to the noise and data deficiency of the XRD profile.

  6. Added value of 80 kVp images to averaged 120 kVp images in the detection of hepatocellular carcinomas in liver transplantation candidates using dual-source dual-energy MDCT: Results of JAFROC analysis

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ji Hoon [Department of Radiology, Seoul National University Hospital (Korea, Republic of); Kim, Se Hyung, E-mail: shkim@radcom.snu.ac.kr [Department of Radiology, Seoul National University Hospital (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Hospital (Korea, Republic of); Park, Hee Sun [Department of Radiology, Konkuk University Hospital (Korea, Republic of); Kim, Gi Hyeon [Department of Radiology, Chung-Ang University Hospital (Korea, Republic of); Lee, Jae Young; Lee, Jeong Min; Han, Joon Koo; Choi, Byung Ihn [Department of Radiology, Seoul National University Hospital (Korea, Republic of); The Institute of Radiation Medicine, Seoul National University Hospital (Korea, Republic of)

    2011-11-15

    Background: To assess the added value of 80 kVp images to weighted average 120 kVp images for detecting hepatocellular carcinomas (HCCs) using dual-source, dual-energy MDCT. Materials and methods: Forty-one HCCs in 42 patients who underwent liver transplantation (LT) were included. All patients underwent quadruple-phase CT using a 64-row dual-source, dual-energy MDCT with 80 kVp and 140 kVp. For 120 kVp, a linear blending ratio of 0.3 was chosen. Interval reviews for both simulated 120 kVp images without and with pure 80 kVp data were performed independently by two radiologists. They detected HCCs using a 4-point confidence scale. Tumor-to-liver contrast-to-noise ratio (CNR) was calculated and compared between the 80 kVp and simulated 120 kVp images. The additional diagnostic value of 80 kVp images was evaluated by jackknife alternative free-response receiver-operating characteristic (JAFROC) analysis. Results: There were 41 HCCs on pathology and 37 of the 41 HCCs were depicted on CT scan. The mean CNR of the 37 HCCs in late arterial and portal-phase images was significantly better in the 80 kVp images than in 120 kVp images. The average JAFROC figure of merit, however, was not significantly improved when 80 kVp was added. Furthermore, the number of false-positives was significantly increased in reader 1 when adding 80 kVp data. Conclusion: The addition of 80 kVp CT images to simulated 120 kVp images did not significantly improve the detection of HCCs despite of the significantly better CNR of 80 kVp images.

  7. Dual-modality PET/CT instrumentation-today and tomorrow

    DEFF Research Database (Denmark)

    Lonsdale, Markus Nowak; Beyer, Thomas

    2010-01-01

    for accurate lesion localization. After a decade of PET/CT these combined systems have matured technically. Today, whole-body oncology staging is available with PET/CT in 15 min, or less. This review details recent developments in combined PET/CT instrumentation and points to implications for major......Positron emission tomography (PET) has proven to be a clinically valuable imaging modality, particularly for oncology staging and therapy follow-up. The introduction of combined PET/CT imaging has helped address challenging imaging situations when anatomical information on PET-only was inadequate...

  8. Evaluation of dual energy spectral CT in differentiating metastatic from non-metastatic lymph nodes in rectal cancer: Initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Huanhuan [Department of Radiology, Ruijin Hospital Affiliated to Shanghai Jiaotong University, School of Medicine, Shanghai 200025 (China); Department of Radiology, Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine (China); Yan, Fuhua; Pan, Zilai; Lin, Xiaozhu; Luo, Xianfu; Shi, Cen [Department of Radiology, Ruijin Hospital Affiliated to Shanghai Jiaotong University, School of Medicine, Shanghai 200025 (China); Chen, Xiaoyan [Department of Pathology, Ruijin Hospital Affiliated to Shanghai Jiaotong University, School of Medicine, Shanghai 200025 (China); Wang, Baisong [Department of Biomedical Statistics, Shanghai Jiaotong University, School of Medicine, Shanghai 200025 (China); Zhang, Huan, E-mail: huanzhangy@126.com [Department of Radiology, Ruijin Hospital Affiliated to Shanghai Jiaotong University, School of Medicine, Shanghai 200025 (China)

    2015-02-15

    Highlights: • Colorectal cancer is the third most prevalent cancer and the status of the regional lymph nodes in rectal cancer is considered to be one of the most powerful prognostic factor in the absence of distant metastatic disease. Detecting LNs metastasis is still a challenging problem due to the presence of microscopic metastasis or inflammatory swelling of LNs. • We investigated the value of dual energy spectral CT in differentiating metastatic from non-metastatic lymph nodes in rectal cancer. Our study demonstrated that the quantitative normalized iodine concentration (nIC) could be useful for differentiating metastatic and non-metastatic lymph nodes. The combination of nIC in portal venous phase and conventional size criterion could improve the diagnostic accuracy, sensitivity, specificity, positive predictive value and negative predictive value of rectal cancer. - Abstract: Objectives: To investigate the value of dual energy spectral CT (DEsCT) imaging in differentiating metastatic from non-metastatic lymph nodes in rectal cancer. Methods: Fifty-five patients with rectal cancer underwent the arterial phase (AP) and portal venous phase (PP) contrast-enhanced DEsCT imaging. The virtual monochromatic images and iodine-based material decomposition images derived from DEsCT imaging were interpreted for lymph nodes (LNs) measurement. The short axis diameter and the normalized iodine concentration (nIC) of metastatic and non-metastatic LNs were measured. The two-sample t test was used to compare the short axis diameters and nIC values of metastatic and non-metastatic LNs. ROC analysis was performed to assess the diagnostic performance. Results: One hundred and fifty two LNs including 92 non-metastatic LNs and 60 metastatic LNs were matched using the radiological-pathological correlation. The mean short axis diameter of metastatic LNs was significantly larger than that of the non-metastatic LNs (7.28 ± 2.28 mm vs. 4.90 ± 1.64 mm, P < 0.001). The mean n

  9. Multifunctional dendrimer-based nanoparticles for in vivo MR/CT dual-modal molecular imaging of breast cancer

    Directory of Open Access Journals (Sweden)

    Li K

    2013-07-01

    Full Text Available Kangan Li,1,4,5,* Shihui Wen,2,* Andrew C Larson,4,5 Mingwu Shen,2 Zhuoli Zhang,4,5 Qian Chen,3 Xiangyang Shi,2,3 Guixiang Zhang1 1Department of Radiology, Shanghai First People’s Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People’s Republic of China; 2College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai, People’s Republic of China; 3State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai, People’s Republic of China; 4Departments of Radiology and Biomedical Engineering, Northwestern University, Chicago, IL, USA; 5Robert H Lurie Comprehensive Cancer Center, Chicago, IL, USA *These authors contributed equally to this work Abstract: Development of dual-mode or multi-mode imaging contrast agents is important for accurate and self-confirmatory diagnosis of cancer. We report a new multifunctional, dendrimer-based gold nanoparticle (AuNP as a dual-modality contrast agent for magnetic resonance (MR/computed tomography (CT imaging of breast cancer cells in vitro and in vivo. In this study, amine-terminated generation 5 poly(amidoamine dendrimers modified with gadolinium chelate (DOTA-NHS and polyethylene glycol monomethyl ether were used as templates to synthesize AuNPs, followed by Gd(III chelation and acetylation of the remaining dendrimer terminal amine groups; multifunctional dendrimer-entrapped AuNPs (Gd-Au DENPs were formed. The formed Gd-Au DENPs were used for both in vitro and in vivo MR/CT imaging of human MCF-7 cancer cells. Both MR and CT images demonstrate that MCF-7 cells and the xenograft tumor model can be effectively imaged. The Gd-Au DENPs uptake, mainly in the cell cytoplasm, was confirmed by transmission electron microscopy. The cell cytotoxicity assay, cell morphology observation, and flow cytometry show that the developed Gd-Au DENPs have good biocompatibility in the given concentration range. Our results

  10. Dual Z-Source Inverter With Three-Level Reduced Common-Mode Switching

    DEFF Research Database (Denmark)

    Gao, Feng; Loh, Poh Chiang; Blaabjerg, Frede

    2007-01-01

    This paper presents the design of a dual Z-source inverter that can be used with either a single dc source or two isolated dc sources. Unlike traditional inverters, the integration of a properly designed Z-source network and semiconductor switches to the proposed dual inverter allows buck......-boost power conversion to be performed over a wide modulation range, with three-level output waveforms generated. The connection of an additional transformer to the inverter ac output also allows all generic wye-or delta-connected loads with three-wire or four-wire configuration to be supplied by the inverter....... Modulationwise, the dual inverter can be controlled using a carefully designed carrier-based pulsewidth-modulation (PWM) scheme that will always ensure balanced voltage boosting of the Z-source network while simultaneously achieving reduced common-mode switching. Because of the omission of dead-time delays...

  11. New Applications of Cardiac Computed Tomography Dual-Energy, Spectral, and Molecular CT Imaging

    NARCIS (Netherlands)

    Danad, Ibrahim; Fayad, Zahi A.; Willemink, Martin J.; Min, James K.

    2015-01-01

    Computed tomography (CT) has evolved into a powerful diagnostic tool, and it is impossible to imagine current clinical practice without CT imaging. Because of its widespread availability, ease of clinical application, superb sensitivity for the detection of coronary artery disease, and noninvasive n

  12. Dual-Energy Computed Tomography Angiography of the Head and Neck With Single-Source Computed Tomography: A New Technical (Split Filter) Approach for Bone Removal.

    Science.gov (United States)

    Kaemmerer, Nadine; Brand, Michael; Hammon, Matthias; May, Matthias; Wuest, Wolfgang; Krauss, Bernhard; Uder, Michael; Lell, Michael M

    2016-10-01

    Dual-energy computed tomographic angiography (DE-CTA) has been demonstrated to improve the visualization of the head and neck vessels. The aim of this study was to test the potential of split-filter single-source dual-energy CT to automatically remove bone from the final CTA data set. Dual-energy CTA was performed in 50 consecutive patients to evaluate the supra-aortic arteries, either to grade carotid artery stenosis or to rule out traumatic dissections. Dual-energy CTA was performed on a 128-slice single-source CT system equipped with a special filter array to separate the 120-kV spectrum into a high- and a low-energy spectrum for DE-based automated bone removal. Image quality of fully automated bone suppression and subsequent manual optimization was evaluated by 2 radiologists on maximum intensity projections using a 4-grade scoring system. The effect of image reconstruction with an iterative metal artifact reduction algorithm on DE postprocessing was tested using a 3-grade scoring system, and the time demand for each postprocessing step was measured. Two patients were excluded due to insufficient arterial contrast enhancement; in the remaining 48 patients, automated bone removal could be performed successfully. The addition of iterative metal artifact reduction algorithm improved image quality in 58.3% of the cases. After manual optimization, DE-CTA image quality was rated excellent in 7, good in 29, and moderate in 10 patients. Interobserver agreement was high (κ = 0.85). Stenosis grading was not influenced using DE-CTA with bone removal as compared with the original CTA. The time demand for DE image reconstruction was significantly higher than for single-energy reconstruction (42.1 vs 20.9 seconds). Our results suggest that bone removal in DE-CTA of the head and neck vessels with a single-source CT is feasible and can be performed within acceptable time and moderate user interaction.

  13. Virtual non-contrast dual-energy CT compared to single-energy CT of the urinary tract: a prospective study

    Energy Technology Data Exchange (ETDEWEB)

    Lundin, Margareta; Liden, Mats; Geijer, Haakan; Andersson, Torbjoern [Dept. of Radiology, Oerebro Univ. Hospital, Oerebro Univ., Oerebro (Sweden)], E-mail: margareta.lundin@orebroll.se; Magnuson, Anders [Clinical Epidemiology and Biostatistic Unit, Oerebro Univ. Hospital, Oerebro (Sweden); Mohammed, Ahmed Abdulilah [Dept. of Radiology, Linkoeping Univ. Hospital, Linkoeping (Sweden); Persson, Anders [CMIV Center for Medical Image Science and Visualization, Linkoeping (Sweden)

    2012-07-15

    Background. Dual-energy computed tomography (DECT) has been shown to be useful for subtracting bone or calcium in CT angiography and gives an opportunity to produce a virtual non-contrast-enhanced (VNC) image from a series where contrast agents have been given intravenously. High noise levels and low resolution have previously limited the diagnostic value of the VNC images created with the first generation of DECT. With the recent introduction of a second generation of DECT, there is a possibility of obtaining VNC images with better image quality at hopefully lower radiation dose compared to the previous generation. Purpose. To compare the image quality of the single-energy series to a VNC series obtained with a two generations of DECT scanners. CT of the urinary tract was used as a model. Material and Methods. Thirty patients referred for evaluation of hematuria were examined with an older system (Somatom Definition) and another 30 patients with a new generation (Somatom Definition Flash). One single-energy series was obtained before and one dual-energy series after administration of intravenous contrast media. We created a VNC series from the contrast-enhanced images. Images were assessed concerning image quality with a visual grading scale evaluation of the VNC series with the single-energy series as gold standard. Results. The image quality of the VNC images was rated inferior to the single-energy variant for both scanners, OR 11.5-67.3 for the Definition and OR 2.1-2.8 for the Definition Flash. Visual noise and overall quality were regarded as better with Flash than Definition. Conclusion. Image quality of VNC images obtained with the new generation of DECT is still slightly inferior compared to native images. However, the difference is smaller with the new compared to the older system.

  14. The Impact of Sources of Variability on Parametric Response Mapping of Lung CT Scans.

    Science.gov (United States)

    Boes, Jennifer L; Bule, Maria; Hoff, Benjamin A; Chamberlain, Ryan; Lynch, David A; Stojanovska, Jadranka; Martinez, Fernando J; Han, Meilan K; Kazerooni, Ella A; Ross, Brian D; Galbán, Craig J

    2015-09-01

    Parametric response mapping (PRM) of inspiration and expiration computed tomography (CT) images improves the radiological phenotyping of chronic obstructive pulmonary disease (COPD). PRM classifies individual voxels of lung parenchyma as normal, emphysematous, or nonemphysematous air trapping. In this study, bias and noise characteristics of the PRM methodology to CT and clinical procedures were evaluated to determine best practices for this quantitative technique. Twenty patients of varying COPD status with paired volumetric inspiration and expiration CT scans of the lungs were identified from the baseline COPD-Gene cohort. The impact of CT scanner manufacturer and reconstruction kernels were evaluated as potential sources of variability in PRM measurements along with simulations to quantify the impact of inspiration/expiration lung volume levels, misregistration, and image spacing on PRM measurements. Negligible variation in PRM metrics was observed when CT scanner type and reconstruction were consistent and inspiration/expiration lung volume levels were near target volumes. CT scanner Hounsfield unit drift occurred but remained difficult to ameliorate. Increasing levels of image misregistration and CT slice spacing were found to have a minor effect on PRM measurements. PRM-derived values were found to be most sensitive to lung volume levels and mismatched reconstruction kernels. As with other quantitative imaging techniques, reliable PRM measurements are attainable when consistent clinical and CT protocols are implemented.

  15. Dual energy CT allows for improved characterization of response to antiangiogenic treatment in patients with metastatic renal cell cancer

    Energy Technology Data Exchange (ETDEWEB)

    Hellbach, K.; Sterzik, A.; Sommer, W.; Karpitschka, M.; Hummel, N.; Ingrisch, M.; Graser, A. [Ludwig-Maximilians-University Hospital Munich, Department of Clinical Radiology, Muenchen (Germany); Casuscelli, J.; Staehler, Michael [Ludwig-Maximilians-University Hospital Munich, Department of Urology, Muenchen (Germany); Schlemmer, M. [Krankenhaus Barmherzige Brueder Muenchen, Department of Palliative Care, Muenchen (Germany)

    2017-06-15

    To evaluate the potential role of dual energy CT (DECT) to visualize antiangiogenic treatment effects in patients with metastatic renal cell cancer (mRCC) while treated with tyrosine-kinase inhibitors (TKI). 26 patients with mRCC underwent baseline and follow-up single-phase abdominal contrast enhanced DECT scans. Scans were performed immediately before and 10 weeks after start of treatment with TKI. Virtual non-enhanced (VNE) and colour coded iodine images were generated. 44 metastases were measured at the two time points. Hounsfield unit (HU) values for VNE and iodine density (ID) as well as iodine content (IC) in mg/ml of tissue were derived. These values were compared to the venous phase DECT density (CTD) of the lesions. Values before and after treatment were compared using a paired Student's t test. Between baseline and follow up, mean CTD and DECT-derived ID both showed a significant reduction (p < 0.005). The relative reduction measured in percent was significantly greater for ID than for CTD (49.8 ± 36,3 % vs. 29.5 ± 20.8 %, p < 0.005). IC was also significantly reduced under antiangiogenic treatment (p < 0.0001). Dual energy CT-based quantification of iodine content of mRCC metastases allows for significantly more sensitive and reproducible detection of antiangiogenic treatment effects. (orig.)

  16. Multiple instance learning for computer aided detection and diagnosis of gastric cancer with dual-energy CT imaging.

    Science.gov (United States)

    Li, Chao; Shi, Cen; Zhang, Huan; Chen, Yazhu; Zhang, Su

    2015-10-01

    Multiple instance learning algorithms have been increasingly utilized in computer aided detection and diagnosis field. In this study, we propose a novel multiple instance learning method for the identification of tumor invasion depth of gastric cancer with dual-energy CT imaging. In the proposed scheme, two level features, bag-level features and instance-level features are extracted for subsequent processing and classification work. For instance-level features, there is some ambiguity in assigning labels to selected patches. An improved Citation-KNN method is presented to solve this problem. Compared with benchmarking state-of-the-art multiple instance learning algorithms using the same clinical dataset, the proposed algorithm can achieve improved results. The experimental evaluation is performed using leave-one-out cross validation with the total accuracy of 0.7692. The proposed multiple instance learning algorithm serves as an alternative method for computer aided diagnosis and identification of tumor invasion depth of gastric cancer with dual-energy CT imaging techniques.

  17. Dual-energy computed tomography for the assessment of early treatment effects of regorafenib in a preclinical tumor model: comparison with dynamic contrast-enhanced CT and conventional contrast-enhanced single-energy CT

    Energy Technology Data Exchange (ETDEWEB)

    Knobloch, Gesine; Hamm, Bernd [Charite - Universitaetsmedizin Berlin, Department of Radiology, Berlin (Germany); Jost, Gregor; Pietsch, Hubertus [Bayer Healthcare, MR and CT Contrast Media Research, Berlin (Germany); Huppertz, Alexander [Imaging Science Institute Charite - Siemens, Berlin (Germany)

    2014-08-15

    The potential diagnostic value of dual-energy computed tomography (DE-CT) compared to dynamic contrast-enhanced CT (DCE-CT) and conventional contrast-enhanced CT (CE-CT) in the assessment of early regorafenib treatment effects was evaluated in a preclinical setting. A rat GS9L glioma model was examined with contrast-enhanced dynamic DE-CT measurements (80 kV/140 kV) for 4 min before and on days 1 and 4 after the start of daily regorafenib or placebo treatment. Tumour time-density curves (0-240 s, 80 kV), DE-CT (60 s) derived iodine maps and the DCE-CT (0-30 s, 80 kV) based parameters blood flow (BF), blood volume (BV) and permeability (PMB) were calculated and compared to conventional CE-CT (60 s, 80 kV). The regorafenib group showed a marked decrease in the tumour time-density curve, a significantly lower iodine concentration and a significantly lower PMB on day 1 and 4 compared to baseline, which was not observed for the placebo group. CE-CT showed a significant decrease in tumour density on day 4 but not on day 1. The DE-C