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Baader E, Klein L, Maier J, Sawall S, Kachelrieß M. Patient radiation risk reduction by controlling the tube start angle in single and dual source spiral CT scans: A simulation study. Med Phys 2024. [PMID: 38991121 DOI: 10.1002/mp.17290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 06/05/2024] [Accepted: 06/10/2024] [Indexed: 07/13/2024] Open
Abstract
BACKGROUND Organ doses in spiral CT scans depend on the tube start angle. PURPOSE To determine the effective dose in single source CT (SSCT) and dual source CT (DSCT) scans as a function of tube start angle and spiral pitch value to identify the dose reduction potential by selecting the optimal start angle. METHODS Using Monte Carlo simulations, dose values for different tube positions with an angular increment of10 ∘ $10^\circ$ and a longitudinal increment of4.5 m m $4.5 \,\mathrm{m}\mathrm{m}$ were simulated over a range of31.5 c m $31.5 \,\mathrm{c}\mathrm{m}$ with collimations of40 mm $40\, \mathrm{mm}$ ,60 mm $60\, \mathrm{mm}$ , and80 m m $80 \,\mathrm{m}\mathrm{m}$ . The simulations were performed for the thorax region of six adult patients based on clinical CT data. From the resulting dose distributions, organ doses and effective dose were determined as a function of tube angle and longitudinal position. Using these per-view dose data, the individual organ doses, as well as the total effective dose, were determined for spiral scans with and without tube current modulation (TCM) with pitch values ranging from 0.5 to 1.5 for SSCT and up to 3.0 for DSCT. The dose of the best and worst tube start angle in terms of dose was determined and compared to the mean dose over all tube start angles. RESULTS With increasing pitch and collimation, the dose variations from the effective dose averaged over all start angles increase. While for a collimation of40 m m $40 \,\mathrm{m}\mathrm{m}$ , the variations from the mean dose value stay below5 % $5 \%$ for SSCT, we find that for a spiral scan with a pitch of 3.0 for DSCT with TCM and collimation of80 m m $80 \,\mathrm{m}\mathrm{m}$ , the dose for the best starting angle is on average16 % $16 \%$ lower than the mean value and28 % $28 \%$ lower than the maximum value. CONCLUSIONS Variation of the tube start angle in spiral scans exhibits substantial differences in radiation dose especially for high pitch values and for high collimations. Therefore, we suggest to control the tube start angle to minimize patient risk.
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Affiliation(s)
- Edith Baader
- Division of X-Ray Imaging and CT, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Department of Physics and Astronomy, Heidelberg University, Heidelberg, Germany
| | - Laura Klein
- Division of X-Ray Imaging and CT, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Department of Physics and Astronomy, Heidelberg University, Heidelberg, Germany
| | - Joscha Maier
- Division of X-Ray Imaging and CT, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Stefan Sawall
- Division of X-Ray Imaging and CT, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Medical Faculty, Heidelberg University, Heidelberg, Germany
| | - Marc Kachelrieß
- Division of X-Ray Imaging and CT, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Medical Faculty, Heidelberg University, Heidelberg, Germany
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Renapurkar RD, Bullen J, Rizk A, Abozeed M, Karim W, Bin Saeedan M, Tong MZ, Heresi GA. A Novel Dual Energy Computed Tomography Score Correlates With Postoperative Outcomes in Chronic Thromboembolic Pulmonary Hypertension. J Thorac Imaging 2024; 39:178-184. [PMID: 37423613 DOI: 10.1097/rti.0000000000000724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
PURPOSE To compare dual-energy computed tomography (DECT) based qualitative and quantitative parameters in chronic thromboembolic pulmonary hypertension with various postoperative primary and secondary endpoints. MATERIALS AND METHODS This was a retrospective analysis of 64 patients with chronic thromboembolic pulmonary hypertension who underwent DECT. First, a clot score was calculated by assigning the following score: pulmonary trunk-5, each main pulmonary artery-4, each lobar-3, each segmental-2, and subsegmental-1 per lobe; the sum total was then calculated. The perfusion defect (PD) score was calculated by assigning 1 point to each segmental PD. The combined score was calculated by adding clot and PD scores. For quantitative evaluation, we calculated perfused blood volume (PBV) (%) of each lung and the sum of both lungs. Primary endpoints included testing association between combined score and total PBV with change in mean pulmonary arterial pressure ([mPAP], change calculated as preop minus postop values). Secondary endpoints included explorative analysis of the correlation between combined score and PBV with change in preoperative and postoperative pulmonary vascular resistance, change in preoperative 6-minute walk distance (6MWD), and immediate postoperative complications such as reperfusion edema, ECMO placement, stroke, death and mechanical ventilation for more than 48 hours, all within 1 month of surgery. RESULTS Higher combined scores were associated with larger decreases in mPAP ( =0.27, P =0.036). On average, the decrease in mPAP (pre mPAP-post mPAP) increased by 2.2 mm Hg (95% CI: -0.6, 5.0) with each 10 unit increase in combined score. The correlation between total PBV and change in mPAP was small and not statistically significant. During an exploratory analysis, higher combined scores were associated with larger increases in 6MWD at 6 months postprocedure ( =0.55, P =0.002). CONCLUSION Calculation of DECT-based combined score offers potential in the evaluation of hemodynamic response to surgery. This response can also be objectively quantified.
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Affiliation(s)
| | | | - Alain Rizk
- Section of Thoracic Imaging, Imaging Institute
| | | | - Wadih Karim
- Section of Thoracic Imaging, Imaging Institute
| | | | | | - Gustavo A Heresi
- Department of Pulmonary and Critical Care Medicine, Cleveland Clinic, Cleveland, OH
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Dual-source computed tomography protocols for the pediatric chest - scan optimization techniques. Pediatr Radiol 2022:10.1007/s00247-022-05468-7. [PMID: 35948645 PMCID: PMC9365683 DOI: 10.1007/s00247-022-05468-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 06/28/2022] [Accepted: 07/21/2022] [Indexed: 11/26/2022]
Abstract
The gold standard for pediatric chest imaging remains the CT scan. An ideal pediatric chest CT has the lowest radiation dose with the least motion degradation possible in a diagnostic scan. Because of the known inherent risks and costs of anesthesia, non-sedate options are preferred. Dual-source CTs are currently the fastest, lowest-dose CT scanners available, utilizing an ultra-high-pitch mode resulting in sub-second CTs. The dual-energy technique, available on dual-source CT scanners, gathers additional information such as pulmonary blood volume and includes relative contrast enhancement and metallic artifact reduction, features that are not available in high-pitch flash mode. In this article we discuss the benefits and tradeoffs of dual-source CT scan modes and tips on image optimization.
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Abozeed M, Conic S, Bullen J, Rizk A, Saeedan MB, Karim W, Heresi GA, Renapurkar RD. Dual energy CT based scoring in chronic thromboembolic pulmonary hypertension and correlation with clinical and hemodynamic parameters: a retrospective cross-sectional study. Cardiovasc Diagn Ther 2022; 12:305-313. [PMID: 35800352 PMCID: PMC9253168 DOI: 10.21037/cdt-21-686] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 04/02/2022] [Indexed: 06/14/2024]
Abstract
BACKGROUND We used a dual energy computed tomography (DECT) based scoring system in patients with chronic thromboembolic pulmonary hypertension (CTEPH) and correlated it with functional and hemodynamic parameters. METHODS This was a retrospective study on 78 patients with CTEPH who underwent DECT. First, clot burden score was calculated by assigning a following score: pulmonary trunk-5, each main pulmonary artery-4, each lobar-3, each segmental-2, and subsegmental-1 per lobe; sum total was then calculated. Perfusion defect (PD) score was calculated by assigning 1 point to each segmental PD. Combined score was calculated by adding the clot burden and PD score. All three scores were correlated with clinical and hemodynamic parameters that included New York Heart Association (NYHA) functional class, 6-minute walk distance (6MWT) in feet, forced expiratory volume in one second (FEV1), forced vital capacity (FVC), diffusing capacity of the lung for carbon monoxide (DLCO), pulmonary arterial pressure (PAP) [systolic PAP (sPAP), diastolic PAP (dPAP) and mean PAP (mPAP)], pulmonary vascular resistance (PVR), right atrial pressure, cardiac output, and cardiac index. RESULTS Clot burden score, PD score, and combined score all positively correlated with sPAP (0.25, 0.34, 0.34), PVR (0.27, 0.30, 0.34), and mPAP (0.28, 0.31, 0.36). There was no statistically significant correlation of clot burden score, PD score and combined score with 6MWT, % predicted 6MWT, FEV1, FEV1%, FVC, FVC%, DLCO% and NYHA functional class. CONCLUSIONS DECT based scoring in CTEPH is feasible and correlates positively with sPAP, mPAP and PVR. Combined score has the highest magnitude of correlation.
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Affiliation(s)
- Mostafa Abozeed
- Sections of Thoracic and Cardiovascular Imaging Laboratory, Imaging Institute, Cleveland Clinic, OH, USA
| | - Sofija Conic
- Sections of Thoracic and Cardiovascular Imaging Laboratory, Imaging Institute, Cleveland Clinic, OH, USA
| | | | - Alain Rizk
- Sections of Thoracic and Cardiovascular Imaging Laboratory, Imaging Institute, Cleveland Clinic, OH, USA
| | - Mnahi Bin Saeedan
- Sections of Thoracic and Cardiovascular Imaging Laboratory, Imaging Institute, Cleveland Clinic, OH, USA
| | - Wadih Karim
- Sections of Thoracic and Cardiovascular Imaging Laboratory, Imaging Institute, Cleveland Clinic, OH, USA
| | - Gustavo A. Heresi
- Department of Pulmonary and Critical Care Medicine, Respiratory Institute, Cleveland Clinic, OH, USA
| | - Rahul D. Renapurkar
- Sections of Thoracic and Cardiovascular Imaging Laboratory, Imaging Institute, Cleveland Clinic, OH, USA
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Ugawa S, Akagi S, Ejiri K, Nakamura K, Ito H. Quantification of Lung Perfusion Blood Volume in Dual-Energy Computed Tomography in Patients with Pulmonary Hypertension. Life (Basel) 2022; 12:684. [PMID: 35629352 PMCID: PMC9143856 DOI: 10.3390/life12050684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 04/28/2022] [Accepted: 05/03/2022] [Indexed: 11/17/2022] Open
Abstract
Dual-energy computed tomography (DECT) is a promising technique for the assessment of the lung perfused blood volume (LPBV) in the lung parenchyma. This study was performed to compare the LPBV by DECT of patients with pulmonary hypertension (PH) and controls and to evaluate the association between the LPBV and the perfusion ratio derived by lung perfusion scintigraphy. This study involved 45 patients who underwent DECT (25 patients with PH and 20 controls). We measured the total LPBV and distribution of the LPBV in each lung. The total LPBV was significantly lower in the PH group than the control group (38 ± 9 vs. 45 ± 8 HU, p = 0.024). Significant differences were observed between the LPBV of the upper lung of the PH and control groups (34 ± 10 vs. 47 ± 10, p = 0.021 and 37 ± 10 vs. 47 ± 8, p < 0.001). A significant correlation was observed between the LPBV and the lung perfusion scintigraphy. A lower total LPBV and lower LPBV of the upper lung as detected by DECT might be specific findings of PH.
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Affiliation(s)
- Satoko Ugawa
- Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama 700-8558, Japan; (S.U.); (K.E.); (K.N.); (H.I.)
- Department of Cardiology, Kagawa Prefectural Central Hospital, Takamatsu 760-8557, Japan
| | - Satoshi Akagi
- Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama 700-8558, Japan; (S.U.); (K.E.); (K.N.); (H.I.)
| | - Kentaro Ejiri
- Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama 700-8558, Japan; (S.U.); (K.E.); (K.N.); (H.I.)
| | - Kazufumi Nakamura
- Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama 700-8558, Japan; (S.U.); (K.E.); (K.N.); (H.I.)
| | - Hiroshi Ito
- Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama 700-8558, Japan; (S.U.); (K.E.); (K.N.); (H.I.)
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Alenezi F, Covington TA, Mukherjee M, Mathai SC, Yu PB, Rajagopal S. Novel Approaches to Imaging the Pulmonary Vasculature and Right Heart. Circ Res 2022; 130:1445-1465. [PMID: 35482838 PMCID: PMC9060389 DOI: 10.1161/circresaha.121.319990] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
There is an increased appreciation for the importance of the right heart and pulmonary circulation in several disease states across the spectrum of pulmonary hypertension and left heart failure. However, assessment of the structure and function of the right heart and pulmonary circulation can be challenging, due to the complex geometry of the right ventricle, comorbid pulmonary airways and parenchymal disease, and the overlap of hemodynamic abnormalities with left heart failure. Several new and evolving imaging modalities interrogate the right heart and pulmonary circulation with greater diagnostic precision. Echocardiographic approaches such as speckle-tracking and 3-dimensional imaging provide detailed assessments of regional systolic and diastolic function and volumetric assessments. Magnetic resonance approaches can provide high-resolution views of cardiac structure/function, tissue characterization, and perfusion through the pulmonary vasculature. Molecular imaging with positron emission tomography allows an assessment of specific pathobiologically relevant targets in the right heart and pulmonary circulation. Machine learning analysis of high-resolution computed tomographic lung scans permits quantitative morphometry of the lung circulation without intravenous contrast. Inhaled magnetic resonance imaging probes, such as hyperpolarized 129Xe magnetic resonance imaging, report on pulmonary gas exchange and pulmonary capillary hemodynamics. These approaches provide important information on right ventricular structure and function along with perfusion through the pulmonary circulation. At this time, the majority of these developing technologies have yet to be clinically validated, with few studies demonstrating the utility of these imaging biomarkers for diagnosis or monitoring disease. These technologies hold promise for earlier diagnosis and noninvasive monitoring of right heart failure and pulmonary hypertension that will aid in preclinical studies, enhance patient selection and provide surrogate end points in clinical trials, and ultimately improve bedside care.
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Affiliation(s)
- Fawaz Alenezi
- Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, NC
| | | | | | - Steve C. Mathai
- Johns Hopkins Division of Pulmonary and Critical Care Medicine, Baltimore, MD
| | - Paul B. Yu
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA
| | - Sudarshan Rajagopal
- Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, NC
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An J, Nam Y, Cho H, Chang J, Kim DK, Lee KS. Acute Pulmonary Embolism and Chronic Thromboembolic Pulmonary Hypertension: Clinical and Serial CT Pulmonary Angiographic Features. J Korean Med Sci 2022; 37:e76. [PMID: 35289137 PMCID: PMC8921210 DOI: 10.3346/jkms.2022.37.e76] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 02/09/2022] [Indexed: 11/22/2022] Open
Abstract
In acute pulmonary embolism (PE), circulatory failure and systemic hypotension are important clinically for predicting poor prognosis. While pulmonary artery (PA) clot loads can be an indicator of the severity of current episode of PE or treatment effectiveness, they may not be used directly as an indicator of right ventricular (RV) failure or patient death. In other words, pulmonary vascular resistance or patient prognosis may not be determined only with mechanical obstruction of PAs and their branches by intravascular clot loads on computed tomography pulmonary angiography (CTPA), but determined also with vasoactive amines, reflex PA vasoconstriction, and systemic arterial hypoxemia occurring during acute PE. Large RV diameter with RV/left ventricle (LV) ratio > 1.0 and/or the presence of occlusive clot and pulmonary infarction on initial CTPA, and clinically determined high baseline PA pressure and RV dysfunction are independent predictors of oncoming chronic thromboembolic pulmonary hypertension (CTEPH). In this pictorial review, authors aimed to demonstrate clinical and serial CTPA features in patients with acute massive and submassive PE and to disclose acute CTPA and clinical features that are related to the prediction of oncoming CTEPH.
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Affiliation(s)
- Junho An
- Department of Radiology, Samsung ChangWon Hospital, Sungkyunkwan University School of Medicine, Changwon, Korea
| | - Yoojin Nam
- Department of Radiology, Samsung ChangWon Hospital, Sungkyunkwan University School of Medicine, Changwon, Korea
| | - Hyoun Cho
- Department of Radiology, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Jeonga Chang
- Department of Radiology, Samsung ChangWon Hospital, Sungkyunkwan University School of Medicine, Changwon, Korea
| | - Duk-Kyung Kim
- Division of Cardiology, Cardiac and Vascular Center, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Kyung Soo Lee
- Department of Radiology, Samsung ChangWon Hospital, Sungkyunkwan University School of Medicine, Changwon, Korea.
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Ye C, Zhang Z, Chen R, Wang J. Value of magnetic resonance combined with dual-source spectral computed tomography in improving the clinical diagnosis and treatment efficiency of lumbar disk herniation. Rev Assoc Med Bras (1992) 2021; 67:811-815. [PMID: 34709322 DOI: 10.1590/1806-9282.20201018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 04/26/2021] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE This study aims to investigate the value of magnetic resonance combined with dual-source spectral computed tomography in improving the clinical diagnosis and treatment efficiency of lumbar disk herniation. METHODS Two hundred patients with lumbar disk herniation were enrolled. Magnetic resonance and dual-source spectral computed tomography were used to perform the diagnosis. The treatment efficiency and effectiveness of different diagnostic methods were determined. RESULTS Eighty cases of lumbar disk herniation, 40 cases of prolapse, 33 cases of bulge, 27 cases of sequestration, and 20 cases of nodules were diagnosed based on pathologic evaluation. magnetic resonance detected lumbar disk herniation in 172 cases, with a detection rate of 86.00%. Dual-source spectral computed tomography detected 171 cases, with a detection rate of 85.50%. Magnetic resonance combined with dual-source spectral computed tomography detected 195 cases, with a detection rate of 97.50%. There was no significant difference between magnetic resonance and dual-source spectral computed tomography (p>0.05), but compared with the combined detection, there was a significant difference (p<0.05). One hundred and two cases of calcification, 83 cases of spinal cord deformity, 70 cases of intervertebral disk degeneration, 121 cases of intervertebral disk gas, 85 cases of dural sac compression, and 78 cases of nerve root compression were surgically demonstrated. The detection rate of diagnostic signs based on imaging by magnetic resonance or dual-source spectral computed tomography alone was lower than that of combined detection (p<0.05). CONCLUSION Magnetic resonance combined with dual-source spectral computed tomography can improve the diagnosis and treatment efficiency and effectiveness of lumbar disk herniation.
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Affiliation(s)
- Chengbin Ye
- The Affiliated People's Hospital of Fujian University of Traditional Chinese Medicine, Department of Radiology - Fuzhou, China
| | - Zhuhui Zhang
- The Affiliated People's Hospital of Fujian University of Traditional Chinese Medicine, Department of Radiology - Fuzhou, China
| | - Ruiyan Chen
- The Affiliated People's Hospital of Fujian University of Traditional Chinese Medicine, Department of Radiology - Fuzhou, China
| | - Junyan Wang
- The Affiliated Hospital, Jiangnan University, Wuhan Sixth Hospital, Department of Radiology - Wuhan, China
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Bos D, König B, Blex S, Zensen S, Opitz M, Maier S, Forsting M, Zylka W, Kühl H, Wetter A, Guberina N. EXPERIMENTAL EXAMINATION OF RADIATION DOSES OF DUAL- AND SINGLE-ENERGY COMPUTED TOMOGRAPHY IN CHEST AND UPPER ABDOMEN IN A PHANTOM STUDY. RADIATION PROTECTION DOSIMETRY 2021; 193:237-246. [PMID: 33893506 DOI: 10.1093/rpd/ncab052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 03/09/2021] [Accepted: 03/25/2021] [Indexed: 06/12/2023]
Abstract
The aim of this phantom study is to examine radiation doses of dual- and single-energy computed tomography (DECT and SECT) in the chest and upper abdomen for three different multi-slice CT scanners. A total of 34 CT protocols were examined with the phantom N1 LUNGMAN. Four different CT examination types of different anatomic regions were performed both in single- and dual-energy technique: chest, aorta, pulmonary arteries for suspected pulmonary embolism and liver. Radiation doses were examined for the CT dose index CTDIvol and dose-length product (DLP). Radiation doses of DECT were significantly higher than doses for SECT. In terms of CTDIvol, radiation doses were 1.1-3.2 times higher, and in terms of DLP, these were 1.1-3.8 times higher for DECT compared with SECT. The third-generation dual-source CT applied the lowest dose in 7 of 15 different examination types of different anatomic regions.
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Affiliation(s)
- Denise Bos
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, Essen 45147, Germany
| | - Britta König
- Faculty of Physical Engineering, Westphalian University, Campus Gelsenkirchen, Neidenburger Str. 43, Gelsenkirchen 45897, Germany
| | - Sebastian Blex
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, Essen 45147, Germany
| | - Sebastian Zensen
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, Essen 45147, Germany
| | - Marcel Opitz
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, Essen 45147, Germany
| | - Sandra Maier
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, Essen 45147, Germany
| | - Michael Forsting
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, Essen 45147, Germany
| | - Waldemar Zylka
- Faculty of Physical Engineering, Westphalian University, Campus Gelsenkirchen, Neidenburger Str. 43, Gelsenkirchen 45897, Germany
| | - Hilmar Kühl
- Department of Radiology, St. Bernhard-Hospital Kamp-Lintfort GmbH, Bürgermeister-Schmelzing-Str. 90, Kamp-Lintfort 47475, Germany
| | - Axel Wetter
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, Essen 45147, Germany
- Department of Diagnostic and Interventional Radiology, Neuroradiology, Asklepios Klinikum Harburg, Eißendorfer Pferdeweg 52, Hamburg 21075, Germany
| | - Nika Guberina
- Department of Radiotherapy, West German Cancer Center, University Hospital Essen, Hufelandstrasse 55, Essen 45147, Germany
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Morphologic and Functional Dual-Energy CT Parameters in Patients With Chronic Thromboembolic Pulmonary Hypertension and Chronic Thromboembolic Disease. AJR Am J Roentgenol 2020; 215:1335-1341. [PMID: 32991219 DOI: 10.2214/ajr.19.22743] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE. The objective of our study was to compare morphologic and functional dual-energy CT (DECT) parameters in patients with chronic thromboembolic disease (CTED) and chronic thromboembolic pulmonary hypertension (CTEPH). MATERIALS AND METHODS. Using the local CTEPH registry, we identified 28 patients with CTED and 72 patients with CTEPH. On each DECT examination, a clot burden score was calculated by assigning the following scores for chronic changes by location: pulmonary trunk, 5; each main pulmonary artery (MPA), 4; each lobar branch, 3; each segmental branch, 2; and each subsegmental branch, 1. The total clot burden score was calculated by adding the individual scores from both lungs. Functional parameters were assessed using perfused blood volume (PBV) maps and included lung enhancement (in Hounsfield units), percentage of PBV, MPA peak enhancement (in Hounsfield units), maximum enhancement corresponding to 100, and the ratio of MPA peak enhancement to lung enhancement. A perfusion defect (PD) score was calculated by assigning 1 point to each segmental PD. Patients with CTED and patients with CTEPH were matched using propensity score matching to account for potential confounders. RESULTS. After matching, the CTEPH group showed a higher PD score than the CTED group and unilateral disease was more common in the CTED group than in the CTEPH group. In the unmatched sample, patients with CTED showed increased percentages of PBV for both lungs (PBV total) and for the right lung as compared with the CTEPH group (adjusted p = 0.040 and 0.028, respectively); after adjustment for clot burden, the difference between groups was still noted but was not statistically significant. No statistically significant differences were noted in the various functional DECT parameters after propensity score matching. CONCLUSION. Patients with CTED show anatomic and functional changes in the pulmonary vasculature and lung parenchyma similar to those seen in patients with CTEPH. Functional DECT parameters support the observation that CTED is an intermediate clinical phenotype in the population with chronic pulmonary embolism.
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Evaluation of Vascular Parameters in Patients With Pulmonary Thromboembolic Disease Using Dual-energy Computed Tomography. J Thorac Imaging 2020; 34:367-372. [PMID: 30562223 DOI: 10.1097/rti.0000000000000383] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
PURPOSE The purpose of this study was to evaluate patterns of vascular and lung parenchymal enhancement in patients with suspected chronic thromboembolic pulmonary hypertension (CTEPH) and in those with acute pulmonary embolism (PE) and compare those two groups. MATERIALS AND METHODS We retrospectively studied 186 thoracic DECT studies referred for evaluation of CTEPH or pulmonary hypertension. A total of 80 of these patients had a negative scan (control group), 13 had acute PE, and 53 had chronic thromboembolic disease (CTED)/CTEPH. Five different DECT-based parameters were evaluated that highlight patterns of vascular kinetics. Specifically, total DECT-based parenchymal attenuation in Hounsfield Unit (HU) (LungHU), percentage of perfused blood volume (PBV), peak enhancement of main pulmonary artery (PApeak in HU), maximum enhancement corresponding to 100 (PAmax), and the ratio of PApeak to LungHU were calculated. RESULTS Compared with patients with negative CT, patients with CTED/CTEPH tended to have lower LungHU (median: 27 vs. 38, P<0.001), lower PBV (median: 39 vs. 51, P=0.003), and higher PApeak/LungHU ratio (median: 17 vs. 13, P=0.003). Compared with patients with acute PE, patients with CTED/CTEPH tended to have lower LungHU (median: 27 vs. 39, P=0.006), lower PBV (median: 39 vs. 62, P=0.023), and higher PApeak/LungHU ratio (median: 17 vs. 11, P=0.023). No statistically significant differences were observed between patients with acute PE and those with negative CT. CONCLUSIONS DECT-based vascular parameters offer the potential to differentiate patients with acute versus chronic PE. These various anatomic and functional vascular DECT-based parameters might be reflective of the state of the underlying vascular bed.
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Haramati A, Haramati LB. Imaging of Chronic Thromboembolic Disease. Lung 2020; 198:245-255. [PMID: 32166427 DOI: 10.1007/s00408-020-00344-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 02/28/2020] [Indexed: 12/19/2022]
Abstract
Acute pulmonary embolism (PE) is a leading cause of cardiovascular morbidity. The most common long-term complication of acute PE is chronic thromboembolic disease, a heterogenous entity which ranges from asymptomatic imaging sequelae to persistent symptoms. Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare disease that can develop in this population and represents the only treatable type of pulmonary hypertension. Recognition of the characteristic findings of chronic pulmonary embolism and CTEPH provides not only diagnostic information, but is also crucial for guiding therapy. The present state-of-the-art review focuses on the multimodality imaging features of chronic pulmonary embolism. Detailed description and illustrations of relevant imaging findings will be demonstrated for ventilation/perfusion (V/Q) scan, CT scan and Dual-Energy CT and MRI and features that distinguish chronic PE from common imaging mimics.
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Affiliation(s)
- Adina Haramati
- Department of Radiology, Northwell Health, Manhasset, NY, USA.
| | - Linda B Haramati
- Departments of Radiology and Internal Medicine, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, NY, USA
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Utility of Iodine Density Perfusion Maps From Dual-Energy Spectral Detector CT in Evaluating Cardiothoracic Conditions: A Primer for the Radiologist. AJR Am J Roentgenol 2020; 214:775-785. [PMID: 32045305 DOI: 10.2214/ajr.19.21818] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
OBJECTIVE. The purpose of this article is to outline the utility of iodine density maps for evaluating cardiothoracic disease and abnormalities. Multiple studies have shown that the variety of images generated from dual-energy spectral detector CT (SDCT) improve identification of cardiothoracic conditions. CONCLUSION. Understanding the technique of SDCT and being familiar with the features of different cardiothoracic conditions on iodine density map images help the radiologist make a better diagnosis.
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Poyyamoli S, Swamiappan E, Gandhi J, Ranasingh RK, Cherian MP, Mehta P. Non-aortic vascular findings on chest CT angiogram: including arch vessels and bronchial arteries. Cardiovasc Diagn Ther 2019; 9:S59-S73. [PMID: 31559154 DOI: 10.21037/cdt.2018.09.05] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
CT angiogram (CTA) has become the modality of choice for imaging of thoracic vascular pathologies, involving the aorta and the pulmonary arteries. Apart from showing exquisite details of these large arteries, pathologies and anatomic variants of their branches can also be studied to a great extent. The major branches of aortic arch can be affected by a wide variety of pathologies ranging from atherosclerosis to trauma and vasculitis. Bronchial arteries in spite of supplying only 1% of lung parenchyma can become hypertrophied in various congenital and acquired conditions, becoming an important source of collateral circulation as well as a source for life threatening hemoptysis. CT also plays an important role in diagnosis of vascular compression at the thoracic outlet. With advances in CT technology, the acquisition, interpretation and clinical applications of CT angiography will continue to grow in the years to come.
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Affiliation(s)
- Santhosh Poyyamoli
- Department of Diagnostic and Interventional Radiology, Kovai Medical Center and Hospital, Coimbatore 641014, India
| | - Elango Swamiappan
- Department of Diagnostic and Interventional Radiology, Kovai Medical Center and Hospital, Coimbatore 641014, India
| | - Jenny Gandhi
- Department of Diagnostic and Interventional Radiology, Kovai Medical Center and Hospital, Coimbatore 641014, India
| | - Rahul K Ranasingh
- Department of Diagnostic and Interventional Radiology, Kovai Medical Center and Hospital, Coimbatore 641014, India
| | - Mathew P Cherian
- Department of Diagnostic and Interventional Radiology, Kovai Medical Center and Hospital, Coimbatore 641014, India
| | - Pankaj Mehta
- Department of Diagnostic and Interventional Radiology, Kovai Medical Center and Hospital, Coimbatore 641014, India
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Bustos Fiore A, González Vázquez M, Trinidad López C, Mera Fernández D, Costas Álvarez M. Defectos de perfusión en el mapa de iodo pulmonar: causas y semiología. RADIOLOGIA 2018; 60:303-311. [DOI: 10.1016/j.rx.2017.11.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Revised: 10/22/2017] [Accepted: 11/02/2017] [Indexed: 11/26/2022]
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Bustos Fiore A, González Vázquez M, Trinidad López C, Mera Fernández D, Costas Álvarez M. Perfusion defects in pulmonary perfusion iodine maps: Causes and semiology. RADIOLOGIA 2018. [DOI: 10.1016/j.rxeng.2018.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Nishiyama KH, Saboo SS, Tanabe Y, Jasinowodolinski D, Landay MJ, Kay FU. Chronic pulmonary embolism: diagnosis. Cardiovasc Diagn Ther 2018; 8:253-271. [PMID: 30057874 DOI: 10.21037/cdt.2018.01.09] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Chronic thromboembolic pulmonary hypertension (CTEPH) is a complication of venous thromboembolic disease. Differently from other causes of pulmonary hypertension, CTEPH is potentially curable with surgery (thromboendarterectomy) or balloon pulmonary angioplasty. Imaging plays a central role in CTEPH diagnosis. The combination of techniques such as lung scintigraphy, computed tomography and magnetic resonance angiography provides non-invasive anatomic and functional information. Conventional pulmonary angiography (CPA) with right heart catheterization (RHC) is considered the gold standard method for diagnosing CTEPH. In this review, we discuss the utility of these imaging techniques in the diagnosis of CTEPH.
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Affiliation(s)
- Katia Hidemi Nishiyama
- Department of Thoracic Imaging, Hospital do Coração and DASA (Diagnósticos da América), São Paulo, Brazil
| | - Sachin S Saboo
- Department of Radiology, UT Southwestern Medical Center, Florence Building, Dallas, TX, USA
| | - Yuki Tanabe
- Department of Radiology, UT Southwestern Medical Center, Florence Building, Dallas, TX, USA
| | | | - Michael J Landay
- Department of Radiology, UT Southwestern Medical Center, Florence Building, Dallas, TX, USA
| | - Fernando Uliana Kay
- Department of Radiology, UT Southwestern Medical Center, Florence Building, Dallas, TX, USA
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Kharat A, Hachulla AL, Noble S, Lador F. Modern diagnosis of chronic thromboembolic pulmonary hypertension. Thromb Res 2017; 163:260-265. [PMID: 28918335 DOI: 10.1016/j.thromres.2017.09.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 07/26/2017] [Accepted: 09/04/2017] [Indexed: 12/28/2022]
Abstract
Chronic thromboembolic pulmonary hypertension (CTEPH) should be suspected in patients presenting persistent dyspnea three months after a pulmonary embolism or in patients presenting with acute pulmonary embolism and suggestive images on the CT-scan. For these patients, a specific diagnostic work-up should be performed. First step consists of the ventilation/perfusion (V/Q) scan which is a good screening test due to its high sensitivity and high negative predictive value. Pulmonary angiography remains the gold standard approach for the confirmation of the diagnosis and pre-surgical evaluation of CTEPH. New emerging technologies such as Dual-Energy Computed Tomography angiography (DECT) and Computed Tomography angiography (CTA) are developing and broadly available. These non invasive methods provide diagnostic information similar to conventional pulmonary angiography and surgical operability information. They are to be considered as an alternative in the diagnostic approach of patients with CTEPH as presented in the ESC/ERS guidelines. Haemodynamic measurement whiles exercising during right heart catheterization may improve diagnostic sensitivity of CTEPH and could therefore be used as a diagnostic test in patient with normal haemodynamic at rest.
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Affiliation(s)
- Aileen Kharat
- Division of Pneumology, University Hospitals of Geneva, Geneva, Switzerland
| | - Anne-Lise Hachulla
- Division of Radiology, University Hospitals of Geneva, Geneva, Switzerland; Pulmonary Hypertension Program, University Hospitals of Geneva, Geneva, Switzerland
| | - Stéphane Noble
- Division of Cardiology, University Hospitals of Geneva, Geneva, Switzerland; Pulmonary Hypertension Program, University Hospitals of Geneva, Geneva, Switzerland
| | - Frédéric Lador
- Division of Pneumology, University Hospitals of Geneva, Geneva, Switzerland; Pulmonary Hypertension Program, University Hospitals of Geneva, Geneva, Switzerland; Geneva University, Faculty of Medicine, Switzerland.
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Niiniviita H, Kiljunen T, Kulmala J. Comparison of Effective Dose and Image Quality for Newborn Imaging on Seven Commonly Used CT Scanners. RADIATION PROTECTION DOSIMETRY 2017; 174:510-517. [PMID: 27522051 DOI: 10.1093/rpd/ncw229] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 07/06/2016] [Indexed: 06/06/2023]
Abstract
This study compares the image quality and the patient doses on seven different computed tomography (CT) scanners for newborn chest imaging. The dose was measured by using an anthropomorphic newborn phantom and thermoluminescence dosemeters (TLDs). The effective dose was estimated separately based on a dose-length-product display, TLD measurements and the ImPACT CT dose calculation software. The image quality was assessed using a signal-to-noise ratio and a contrast-to-noise ratio (CNR). In order to compare the different scanners, a figure of merit (FOM) based on the rate of CNR2 and computed tomography dose index (CTDIvol) was calculated. The organ doses within the scan area ranged between 0.3 and 2.9 mGy and they depended on the organ and used scanner. The highest effective dose (1.1 mSv) was observed on Aquilion 32 and the lowest effective dose was observed on the Aquilion One (0.22 mSv). The lowest organ doses and highest FOM were observed on the Optima 660. With the Aquilion One and the Definition Dual Flash the examination was 71-90% faster when compared with other scanners. Newer devices equipped with novel dose-saving methods provide a lower dose, as well as take better advantage of the radiation in the image formation.
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Affiliation(s)
- Hannele Niiniviita
- Department of Medical Physics, Turku University Hospital, PO Box 52, FI-20521 Turku, Finland
- Department of Diagnostic Radiology, University of Turku, FI-20014 Turun yliopisto, Finland
| | - Timo Kiljunen
- Docrates Cancer Center, Helsinki, Saukonpaadenranta 2, FI-00180 Helsinki, Finland
| | - Jarmo Kulmala
- Department of Oncology, Turku University Hospital, PO Box 52, FI-20521 Turku, Finland
- Department of Radiology, Turku University Hospital, PO Box 52, FI-20521 Turku, Finland
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Liu L, Zhi X, Liu B, Zhang Y. Utilizing gemstone spectral CT imaging to evaluate the therapeutic efficacy of radiofrequency ablation in lung cancer. Radiol Med 2015; 121:261-7. [PMID: 26612323 DOI: 10.1007/s11547-015-0602-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 11/03/2015] [Indexed: 11/24/2022]
Abstract
PURPOSE To evaluate the therapeutic efficacy of radiofrequency ablation (RFA), quantitative water-based, and iodine-based images of gemstone spectral computed tomography (CT) were analyzed. PATIENTS AND METHODS 30 patients underwent lung RFAs from March 2012 to March 2013. Through enhanced chest scans, we obtained the tumor size values by conventional CT images, and quantitatively analyzed the densities of iodine and water in lung tumors from water-based and iodine-based material decomposition images. RESULTS Tumors in 22 cases increased in size after RFA while there was no detectable change in the remaining 8 cases. Through water-based material decomposition images, the water content in the tumors increased from (1014.76 ± 6.83 mg/mL) to (1022.71 ± 10.16 mg/mL) after RFA, and this difference was significant (t = -2.329, p < 0.05). Through iodine-based material decomposition images, the iodine content in the tumors was 2.49 ± 0.74 mg/mL before RFA. The tumors were mostly or completely necrotized after RFA and the iodine content in the area of necrosis reduced to 0.45 ± 0.29 mg/m (t = 11.072, p = 0.000). CONCLUSION By comparing the tumor size, water content and iodine content before and after RFA, we can visualize the morphology and metabolic states of the tumors and evaluate the therapeutic efficiency.
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Affiliation(s)
- Lei Liu
- Department of Thoracic Surgery, Xuanwu Hospital of Capital Medical University, Beijing, China
| | - Xiuyi Zhi
- Department of Thoracic Surgery, Xuanwu Hospital of Capital Medical University, Beijing, China
| | - Baodong Liu
- Department of Thoracic Surgery, Xuanwu Hospital of Capital Medical University, Beijing, China
| | - Yi Zhang
- Department of Thoracic Surgery, Xuanwu Hospital of Capital Medical University, Beijing, China.
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Ameli-Renani S, Rahman F, Nair A, Ramsay L, Bacon JL, Weller A, Sokhi HK, Devaraj A, Madden B, Vlahos I. Dual-energy CT for imaging of pulmonary hypertension: challenges and opportunities. Radiographics 2015; 34:1769-90. [PMID: 25384277 DOI: 10.1148/rg.347130085] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Computed tomography (CT) is routinely used in the evaluation of patients with pulmonary hypertension (PH) to assess vascular anatomy and parenchymal morphology. The introduction of dual-energy CT (DECT) enables additional qualitative and quantitative insights into pulmonary hemodynamics and the extent and variability of parenchymal enhancement. Lung perfusion assessed at pulmonary blood volume imaging correlates well with findings at scintigraphy, and pulmonary blood volume defects seen in pulmonary embolism studies infer occlusive disease with increased risk of right heart dysfunction. Similarly, perfusion inhomogeneities seen in patients with PH closely reflect mosaic lung changes and may be useful for severity assessment and prognostication. The use of DECT may increase detection of peripheral thromboembolic disease, which is of particular prognostic importance in patients with chronic thromboembolic PH with microvascular involvement. Other DECT applications for imaging of PH include low-kilovoltage images with greater inherent iodine conspicuity and iodine-selective color-coded maps of vascular perfusion (both of which can improve visualization of vascular enhancement), virtual nonenhanced imaging (which better depicts vascular calcification), and, potentially, ventricular perfusion maps (to assess myocardial ischemia). In addition, quantitative assessment of central vascular and parenchymal enhancement can be used to evaluate pulmonary hemodynamics in patients with PH. The current status and potential advantages and limitations of DECT for imaging of PH are reviewed, and current evidence is supplemented with data from a tertiary referral center for PH.
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Affiliation(s)
- Seyed Ameli-Renani
- From the Department of Radiology (S.A.R., F.R., A.N., L.R., A.W., H.K.S., A.D., I.V.) and Pulmonary Hypertension Unit (J.L.B., B.M.), St George's Hospital, Blackshaw Road, London SW17 0PZ, England
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The effect of the section thickness used for 2- and 3-dimensional quantification of dual-energy perfusion computed tomography. J Comput Assist Tomogr 2014; 38:979-84. [PMID: 25229200 DOI: 10.1097/rct.0000000000000148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE To retrospectively investigate the effect of the section thickness used for quantifying dual-energy perfusion computed tomography (DEpCT) during 2- and 3-dimensional evaluation. METHODS Sixty-six patients (22 males and 44 females; mean age, 59.3 years) suspected of having an acute pulmonary embolism underwent DEpCT, and 15patients were diagnosed to have intrapulmonary clots (IPCs). Two-dimensional DEpCT images were reconstructed into various section thicknesses from 1 to 10 mm at the main pulmonary artery, and the ratios of the low attenuation area (LAA) ranging from 1 to 5 HU (%LAA5) and 10 HU (%LAA10) on DEpCT were compared with the relative areas of the lung with attenuation coefficients lower than -950 HU (RA-950) using the lung CT images of each section thickness. Three-dimensional values of DEpCT were reconstructed with 3 different section thicknesses (1, 3, and 10 mm) and were analyzed for the presence of IPC burden using the factors suggesting IPC burden, including the right/left ventricular diameter ratio and CT obstruction index. RESULTS The mean attenuation and image noise were decreased as the section thickness increased. In the 2-dimensional analysis, the %LAA5 and %LAA10 had the smallest value at 1-mm section, and DEpCT with thinner sections had a correlation with the RA-950 (r = 0.22-0.23, P < 0.05). The 3-dimensional values of DEpCT reconstructed with a 1- or 3-mm section thickness had a correlation with the CT obstruction index (r = 0.52-0.59, P < 0.05) and right/left ventricular diameter ratio (r = 0.60-0.68, P < 0.01). CONCLUSIONS The thinner images should be used for 2- and 3-dimensional quantification of DEpCT.
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Dinkel J, Khalilzadeh O, Phan CM, Goenka AH, Yoo AJ, Hirsch JA, Gupta R. Technical limitations of dual-energy CT in neuroradiology: 30-month institutional experience and review of literature. J Neurointerv Surg 2014; 7:596-602. [PMID: 24951287 DOI: 10.1136/neurintsurg-2014-011241] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2014] [Accepted: 06/06/2014] [Indexed: 11/03/2022]
Abstract
BACKGROUND Dual-energy CT (DECT) has been shown to be a useful modality in neuroradiology. OBJECTIVE To assess failure modes and limitations of DECT in different neuroimaging applications. PATIENTS AND METHODS Dual-source DECT scans were performed in 72 patients over 30 months to differentiate contrast agent staining or extravasation from intracranial hemorrhage (ICH) (n=40); to differentiate calcium from ICH (n=2); for metal-artifact reduction (n=5); and for angiographic assessment (n=25). A three-material decomposition algorithm was used to obtain virtual non-contrast (VNC) and iodine (or calcium) overlay images. Images were analyzed in consensus by two board-certified radiologists to determine the success of the algorithm and to assess confounding factors. Furthermore, a dilution experiment using cylinders containing defined heparinized swine blood, normal saline, and selected iodine concentrations was conducted to assess other possible confounding factors. RESULTS Dual-energy analysis was successful in 65 (90.2%) patients. However, the algorithm failed when images were affected by beam hardening (n=3, 4.2%), the presence of a fourth material (parenchymal calcification) (n=3, 4.2%), or motion (n=1, 1.4%). In the dilution experiment, a saturation effect was seen at high iodine concentrations (≥37 mg/ml). VNC and iodine overlay images were not reliable above this concentration, and beam-hardening artifacts were noted. CONCLUSIONS DECT material decomposition is usually successful in neuroradiology. However, it can only distinguish up to three preselected materials. A fourth material such as parenchymal calcium may confound the analysis. Artifacts such as beam hardening, metallic streak, or saturation effect can also impair material decomposition.
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Affiliation(s)
- Julien Dinkel
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA Department of Radiology, University Hospital Heidelberg, Heidelberg, Germany
| | - Omid Khalilzadeh
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Catherine M Phan
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Ajit H Goenka
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Albert J Yoo
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Joshua A Hirsch
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Rajiv Gupta
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
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Abstract
OBJECTIVE Recent technologic advances in MDCT have led to the introduction of dual-energy CT (DECT). The basic principle of DECT is to acquire images at two different energy levels simultaneously and to use the attenuation differences at these different energy levels for deriving additional information, such as virtual monochromatic images, artifact suppression, and material composition of various tissues. CONCLUSION A variety of image reconstruction and postprocessing techniques are available for better demonstration and characterization of pathologic abnormalities. DECT can provide both anatomic and functional information of different organ systems. This article focuses on the main applications of DECT in emergency radiology.
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Ohana M, Jeung MY, Labani A, El Ghannudi S, Roy C. Thoracic dual energy CT: acquisition protocols, current applications and future developments. Diagn Interv Imaging 2014; 95:1017-26. [PMID: 24780370 DOI: 10.1016/j.diii.2014.01.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Thanks to a simultaneous acquisition at high and low kilovoltage, dual energy computed tomography (DECT) can achieve material-based decomposition (iodine, water, calcium, etc.) and reconstruct images at different energy levels (40 to 140keV). Post-processing uses this potential to maximise iodine detection, which elicits demonstrated added value for chest imaging in acute and chronic embolic diseases (increases the quality of the examination and identifies perfusion defects), follow-up of aortic endografts and detection of contrast uptake in oncology. In CT angiography, these unique features are taken advantage of to reduce the iodine load by more than half. This review article aims to set out the physical basis for the technology, the acquisition and post-processing protocols used, its proven advantages in chest pathologies, and to present future developments.
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Affiliation(s)
- M Ohana
- Department of Radiology, Nouvel Hôpital Civil, University Hospitals of Strasbourg, 1, place de l'Hôpital, 67000 Strasbourg, France.
| | - M Y Jeung
- Department of Radiology, Nouvel Hôpital Civil, University Hospitals of Strasbourg, 1, place de l'Hôpital, 67000 Strasbourg, France
| | - A Labani
- Department of Radiology, Nouvel Hôpital Civil, University Hospitals of Strasbourg, 1, place de l'Hôpital, 67000 Strasbourg, France
| | - S El Ghannudi
- Department of Radiology, Nouvel Hôpital Civil, University Hospitals of Strasbourg, 1, place de l'Hôpital, 67000 Strasbourg, France
| | - C Roy
- Department of Radiology, Nouvel Hôpital Civil, University Hospitals of Strasbourg, 1, place de l'Hôpital, 67000 Strasbourg, France
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Aran S, Shaqdan KW, Abujudeh HH. Dual-energy computed tomography (DECT) in emergency radiology: basic principles, techniques, and limitations. Emerg Radiol 2014; 21:391-405. [DOI: 10.1007/s10140-014-1208-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2014] [Accepted: 02/17/2014] [Indexed: 02/05/2023]
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Hu D, Yu T, Duan X, Peng Y, Zhai R. Determination of the optimal energy level in spectral CT imaging for displaying abdominal vessels in pediatric patients. Eur J Radiol 2014; 83:589-94. [DOI: 10.1016/j.ejrad.2013.10.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 10/07/2013] [Accepted: 10/15/2013] [Indexed: 10/26/2022]
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Zhang LJ, Yang GF, Wu SY, Xu J, Lu GM, Schoepf UJ. Dual-energy CT imaging of thoracic malignancies. Cancer Imaging 2013; 13:81-91. [PMID: 23470989 PMCID: PMC3596838 DOI: 10.1102/1470-7330.2013.0009] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Computed tomography (CT) plays a pivotal role in the detection, characterization, and staging of lung cancer and other thoracic malignancies. Since the introduction of clinically viable dual-energy CT techniques, substantial evidence has accumulated on the use of this modality for imaging chest malignancies. This article describes the principles of dual-energy CT along with suitable image acquisition, reconstruction, and postprocessing strategies for oncologic applications in the chest. The potential of dual-energy CT techniques for the detection, characterization, staging, and surveillance of chest malignancy, as well as the limitations of this modality are discussed.
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Affiliation(s)
- Long Jiang Zhang
- Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, 305 Zhongshan East Road, Xuanwu District, Nanjing, Jiangsu Province, 210002, China
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Abstract
OBJECTIVE The introduction of dual-energy CT (DECT) has ushered in the ability of material differentiation and tissue characterization beyond the traditional CT attenuation scale. This quality has been exploited for visualizing and quantifying the specific tissue content using radiographic contrast agents, such as iodine-based contrast media or inhaled xenon gas. Applications of this paradigm in the thorax include characterization of the pulmonary blood pool in the setting of acute or chronic pulmonary embolism (PE) and characterization of diseases of the lung parenchyma. Selective xenon detection is being explored for imaging of lung ventilation. In addition, the usefulness of DECT-based selective iodine uptake measurements has been described for the diagnosis and surveillance of thoracic malignancies. This article reviews the current applications of DECT-based imaging techniques in the chest with an emphasis on the diagnosis and characterization of pulmonary thromboembolic disorders. CONCLUSION DECT can provide both anatomic and functional information about the lungs in a variety of pulmonary disease states based on a single contrast-enhanced CT examination. This quality has been shown to improve the diagnosis of acute and chronic PEs, other vascular disorders, lung malignancies, and parenchymal diseases. Further developments in DECT techniques and CT scanner technology will further foster and enhance the utility of this application and open new avenues in lung imaging.
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Abstract
OBJECTIVE Dual-energy CT permits a variety of image reconstructions for the depiction and characterization of vascular disease. Techniques include visualization of low- and high-peak-kilovoltage spectra image datasets and also material-specific reconstructions combining both low- and high-peak-kilovoltage data. CONCLUSION This article focuses on four main vascular areas: the aorta, the major visceral, lower limb, and cervical arteries. For each territory, the current status, potential advantages, and limitations of these techniques are described.
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Okada M, Kunihiro Y, Nakashima Y, Matsunaga N, Sano Y, Yuasa Y, Narazaki A, Kudomi S, Koike M, Kido S. The low attenuation area on dual-energy perfusion CT: Correlation with the pulmonary function tests and quantitative CT measurements. Eur J Radiol 2012; 81:2892-9. [DOI: 10.1016/j.ejrad.2011.11.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Revised: 11/01/2011] [Accepted: 11/02/2011] [Indexed: 10/14/2022]
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Kim BH, Seo JB, Chae EJ, Lee HJ, Hwang HJ, Lim C. Analysis of perfusion defects by causes other than acute pulmonary thromboembolism on contrast-enhanced dual-energy CT in consecutive 537 patients. Eur J Radiol 2012; 81:e647-52. [DOI: 10.1016/j.ejrad.2012.01.026] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Revised: 01/12/2012] [Accepted: 01/17/2012] [Indexed: 10/14/2022]
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Silva AC, Morse BG, Hara AK, Paden RG, Hongo N, Pavlicek W. Dual-energy (spectral) CT: applications in abdominal imaging. Radiographics 2012; 31:1031-46; discussion 1047-50. [PMID: 21768237 DOI: 10.1148/rg.314105159] [Citation(s) in RCA: 238] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Dual-energy imaging is a promising new development in computed tomography (CT) that has the potential to improve lesion detection and characterization beyond levels currently achievable with conventional CT techniques. In dual-energy CT (DECT), the simultaneous use of two different energy settings allows the differentiation of materials on the basis of their energy-related attenuation characteristics (material density). The datasets obtained with DECT can be used to reconstruct virtual unenhanced images as well as iodinated contrast material-enhanced material density images, obviating the standard two-phase (unenhanced and contrast-enhanced) scanning protocol and thus helping minimize the radiation dose received by the patient. Single-source DECT, which is performed with rapid alternation between two energy levels, can also generate computed monochromatic images, which are less vulnerable to artifacts such as beam hardening and pseudoenhancement and provide a higher contrast-to-noise ratio than polychromatic images produced by conventional CT. Familiarity with the capabilities of DECT may help radiologists improve their diagnostic performance.
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Affiliation(s)
- Alvin C Silva
- Department of Radiology, Mayo Clinic, Scottsdale, AZ 85259, USA.
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Pulmonary blood volume imaging with dual-energy computed tomography: Spectrum of findings. Clin Radiol 2012; 67:69-77. [DOI: 10.1016/j.crad.2010.12.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Revised: 12/10/2010] [Accepted: 12/14/2010] [Indexed: 11/22/2022]
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Ghoshhajra BB, Rogers IS, Maurovich-Horvat P, Techasith T, Verdini D, Sidhu MS, Drzezga NK, Medina HM, Blankstein R, Brady TJ, Cury RC. A comparison of reconstruction and viewing parameters on image quality and accuracy of stress myocardial CT perfusion. J Cardiovasc Comput Tomogr 2011; 5:459-66. [PMID: 22146505 DOI: 10.1016/j.jcct.2011.10.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Revised: 10/23/2011] [Accepted: 10/26/2011] [Indexed: 10/15/2022]
Abstract
BACKGROUND Myocardial stress computed tomography perfusion (CTP) has similar diagnostic accuracy for detecting perfusion defects (PDs) versus single-photon emission computed tomography (SPECT). However, the optimal diagnostic viewing and image processing parameters for CTP are unknown. OBJECTIVE We sought to compare the diagnostic accuracy of different image processing techniques, cardiac phases, slice thicknesses, and viewing parameters for detection of PDs. METHODS A stress and rest dual-source CTP protocol was performed with adenosine. Twelve subjects with severe stenosis proven by quantitative coronary angiography (QCA), with corresponding territorial defects at SPECT, were selected as well as 7 controls (subjects with similar clinical suspicion but negative QCA and SPECT). Short-axis stress images were processed with 3 techniques: minimum intensity projection (MinIP), maximum intensity projection, and average intensity multiplanar reconstruction (MPR), 3 thicknesses (1, 3, 8 mm), and 2 phases (systolic, mid-diastolic). The resulting images (n = 1026) were randomized and interpreted by independent readers. RESULTS Diastolic reconstructions (8-mm MPR) showed the highest sensitivity (81%) to detect true PDs. The highest accuracy was achieved with the 8-mm (61%) and 1-mm (61%) MPR diastolic images. The most sensitive and accurate systolic reconstructions were 3-mm MinIP images. These findings related to viewing in relatively narrow window width and window level settings. CONCLUSION Viewing parameters for optimal accuracy in detection of perfusion defects on CTP differ for systolic and diastolic images.
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Affiliation(s)
- Brian B Ghoshhajra
- Cardiac MR PET CT Program, Department of Radiology and Division of Cardiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
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Renard B, Remy-Jardin M, Santangelo T, Faivre JB, Tacelli N, Remy J, Duhamel A. Dual-energy CT angiography of chronic thromboembolic disease: Can it help recognize links between the severity of pulmonary arterial obstruction and perfusion defects? Eur J Radiol 2011; 79:467-72. [DOI: 10.1016/j.ejrad.2010.04.018] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2009] [Revised: 04/09/2010] [Accepted: 04/14/2010] [Indexed: 11/30/2022]
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Lung imaging in asthmatic patients: the picture is clearer. J Allergy Clin Immunol 2011; 128:467-78. [PMID: 21636118 DOI: 10.1016/j.jaci.2011.04.051] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2010] [Revised: 04/10/2011] [Accepted: 04/18/2011] [Indexed: 01/11/2023]
Abstract
Imaging of the lungs in patients with asthma has evolved dramatically over the last decade with sophisticated techniques, such as computed tomography, magnetic resonance imaging, positron emission tomography, and single photon emission computed tomography. New insights into current and future modalities for imaging in asthmatic patients and their application are discussed to potentially shed a clearer picture of the underlying pathophysiology of asthma, especially severe asthma, and the proposed clinical utility of imaging in patients with this common disease.
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Clinical application of dual-source CT in the evaluation of patients with lung cancer: correlation with perfusion scintigraphy and pulmonary function tests. Radiol Med 2011; 116:842-57. [PMID: 21509557 DOI: 10.1007/s11547-011-0674-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2010] [Accepted: 10/15/2010] [Indexed: 10/18/2022]
Abstract
PURPOSE 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). MATERIALS AND METHODS 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. RESULTS 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). CONCLUSIONS DSCT is a robust and promising technique that provides important and accurate information on lung function.
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Hong YJ, Kim YJ, Lee S, Choe AKO. Evaluation of Lung Perfusion With Dual-Energy Computed Tomography in a Chronic Pulmonary Thromboembolism Patient. Ann Thorac Surg 2011; 91:e62. [DOI: 10.1016/j.athoracsur.2011.01.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2010] [Revised: 01/11/2011] [Accepted: 01/12/2011] [Indexed: 11/29/2022]
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Dual-source dual-energy CT with additional tin filtration: Dose and image quality evaluation in phantoms and in vivo. AJR Am J Roentgenol 2010; 195:1164-74. [PMID: 20966323 DOI: 10.2214/ajr.09.3956] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The objective of this study was to investigate the effect on radiation dose and image quality of the use of additional spectral filtration for dual-energy CT using dual-source CT (DSCT). MATERIALS AND METHODS A commercial DSCT scanner was modified by adding tin filtration to the high-kV tube, and radiation output and noise were measured in water phantoms. Dose values for equivalent image noise were compared between the dual-energy mode with and without tin filtration and the single-energy mode. To evaluate dual-energy CT material discrimination, the material-specific dual-energy ratio for calcium and that for iodine were determined using images of anthropomorphic phantoms. Data were additionally acquired from imaging a 38-kg pig and an 87-kg pig, and the noise of the linearly mixed images and virtual noncontrast images was compared between dual-energy modes. Finally, abdominal dual-energy CT images of two patients of similar sizes undergoing clinically indicated CT were compared. RESULTS Adding tin filtration to the high-kV tube improved the dual-energy contrast between iodine and calcium as much as 290%. Data from our animal study showed that tin filtration had no effect on noise in the dual-energy CT mixed images but decreased noise by as much as 30% in the virtual noncontrast images. Virtual noncontrast images of patients acquired using 100 and 140 kV with added tin filtration had improved image quality relative to those generated using 80 and 140 kV without tin filtration. CONCLUSION Tin filtration of the high-kV tube of a DSCT scanner increases the ability of dual-energy CT to discriminate between calcium and iodine without increasing dose relative to single-energy CT. Furthermore, the use of 100- and 140-kV tube potentials allows improved dual-energy CT imaging of large patients.
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Knöss N, Hoffmann B, Krauss B, Heller M, Biederer J. Dual energy computed tomography of lung nodules: differentiation of iodine and calcium in artificial pulmonary nodules in vitro. Eur J Radiol 2010; 80:e516-9. [PMID: 21112712 DOI: 10.1016/j.ejrad.2010.11.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2010] [Accepted: 11/03/2010] [Indexed: 11/30/2022]
Abstract
BACKGROUND Iodine enhancement is a marker for malignancy in pulmonary nodules. The purpose of this in vitro study was to assess whether dual energy computed tomography (DECT) can be used to detect iodine and to distinguish iodine from disperse calcifications in artificial pulmonary nodules. MATERIALS AND METHODS Small, medium, and large artificial nodules (n=54), with increasing concentrations of iodine or calcium corresponding to an increase in Hounsfield Units (HU) of 15, 30, 45, and 90 at 120 kV, were scanned in a chest phantom with DECT at 80 and 140 kV. Attenuation values of each nodule were measured using semi-automated volumetric analysis. The mean DE ratio with 95% confidence intervals (CI) was calculated for each nodule. RESULTS The mean maximum diameter of the 18 small nodules was 12 mm (standard deviation: 0.4), 16 mm (0.4) for the 18 medium nodules, and 30 mm (1.1) for the 18 large nodules. There was no overlap of 95% CI of DE ratios of iodine and calcium in nodules≥16 mm. In nodules<16 mm, there was an overlap of DE ratios in low contrast lesions. CONCLUSION DECT can distinguish iodine from calcium in artificial nodules≥16 mm in vitro. In smaller lesions, a clear differentiation is not possible.
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Affiliation(s)
- Naomi Knöss
- Department of Radiology, University Hospital Schleswig-Holstein, Campus Kiel, Germany.
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Focal Iodine Defects on Color-Coded Iodine Perfusion Maps of Dual-Energy Pulmonary CT Angiography Images: A Potential Diagnostic Pitfall. AJR Am J Roentgenol 2010; 195:W325-30. [DOI: 10.2214/ajr.09.3241] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Feng ST, Law MWM, Huang B, Ng S, Li ZP, Meng QF, Khong PL. Radiation dose and cancer risk from pediatric CT examinations on 64-slice CT: a phantom study. Eur J Radiol 2010; 76:e19-e23. [PMID: 20363573 DOI: 10.1016/j.ejrad.2010.03.005] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Revised: 02/24/2010] [Accepted: 03/04/2010] [Indexed: 02/06/2023]
Abstract
OBJECTIVE To measure the radiation dose from CT scans in an anthropomorphic phantom using a 64-slice MDCT, and to estimate the associated cancer risk. MATERIALS AND METHODS Organ doses were measured with a 5-year-old phantom and thermoluminescent dosimeters. Four protocols; head CT, thorax CT, abdomen CT and pelvis CT were studied. Cancer risks, in the form of lifetime attributable risk (LAR) of cancer incidence, were estimated by linear extrapolation using the organ radiation doses and the LAR data. RESULTS The effective doses for head, thorax, abdomen and pelvis CT, were 0.7mSv, 3.5mSv, 3.0mSv, 1.3mSv respectively. The organs with the highest dose were; for head CT, salivary gland (22.33mGy); for thorax CT, breast (7.89mGy); for abdomen CT, colon (6.62mGy); for pelvis CT, bladder (4.28mGy). The corresponding LARs for boys and girls were 0.015-0.053% and 0.034-0.155% respectively. The organs with highest LARs were; for head CT, thyroid gland (0.003% for boys, 0.015% for girls); for thorax CT, lung for boys (0.014%) and breast for girls (0.069%); for abdomen CT, colon for boys (0.017%) and lung for girls (0.016%); for pelvis CT, bladder for both boys and girls (0.008%). CONCLUSION The effective doses from these common pediatric CT examinations ranged from 0.7mSv to 3.5mSv and the associated lifetime cancer risks were found to be up to 0.16%, with some organs of higher radiosensitivity including breast, thyroid gland, colon and lungs.
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Affiliation(s)
- Shi-Ting Feng
- Department of Radiology, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
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Kang MJ, Park CM, Lee CH, Goo JM, Lee HJ. Dual-energy CT: clinical applications in various pulmonary diseases. Radiographics 2010; 30:685-98. [PMID: 20462988 DOI: 10.1148/rg.303095101] [Citation(s) in RCA: 134] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The dual-energy computed tomographic (CT) technique allows the differentiation of materials with large atomic numbers such as iodine and xenon. The basic principle of dual-energy CT is material decomposition based on attenuation differences at different energy levels. By using dual-energy CT angiography for the evaluation of perfusion defects in cases of pulmonary embolism, and using xenon CT for the evaluation of ventilation defects, it may be possible to replace perfusion and ventilation scanning. An iodine map from dual-energy CT can demonstrate the distribution of pulmonary perfusion, whereas xenon ventilation CT can be used to generate a ventilation map. Furthermore, the virtual nonenhanced dual-energy CT technique can be used for the evaluation of pulmonary nodule characteristics without acquisition of true nonenhanced CT images. Knowledge of the applications of dual-energy CT and the typical images produced may lead to wider use of dual-energy CT for pulmonary applications and better interpretation of the results.
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Affiliation(s)
- Mi-Jin Kang
- Department of Radiology, Seoul National University Hospital, 28 Yeongeon-dong, Jongno-gu, Seoul 110-744, Korea
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Thieme SF, Johnson TR, Reiser MF, Nikolaou K. Dual-Energy Lung Perfusion Computed Tomography: A Novel Pulmonary Functional Imaging Method. Semin Ultrasound CT MR 2010; 31:301-8. [PMID: 20691930 DOI: 10.1053/j.sult.2010.05.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Lu GM, Wu SY, Yeh BM, Zhang LJ. Dual-energy computed tomography in pulmonary embolism. Br J Radiol 2010; 83:707-18. [PMID: 20551257 DOI: 10.1259/bjr/16337436] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The introduction of modern dual-energy CT (DECT) scanners has enabled contrast material to be distinguished at imaging without the need for a separate unenhanced scan. Images of pulmonary parenchymal contrast enhancement obtained using DECT improve the detection of defects, augmenting our ability to detect pulmonary emboli; however, with these advances new pitfalls are also introduced. In this pictorial review, we present the technique, clinical applications and causes and remedies of false results of dual-energy pulmonary parenchymal enhancement defects in pulmonary embolism.
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Affiliation(s)
- G-M Lu
- Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, Nanjing, Jiangsu 210002, China.
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