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Landsmann A, Sartoretti T, Mergen V, Jungblut L, Eberhard M, Kobe A, Alkadhi H, Euler A. Multi-Energy Low-Kiloelectron Volt versus Single-Energy Low-Kilovolt Images for Endoleak Detection at CT Angiography of the Aorta. Radiol Cardiothorac Imaging 2024; 6:e230217. [PMID: 38451189 PMCID: PMC11056760 DOI: 10.1148/ryct.230217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 01/14/2024] [Accepted: 01/23/2024] [Indexed: 03/08/2024]
Abstract
Purpose To compare image quality, diagnostic performance, and conspicuity between single-energy and multi-energy images for endoleak detection at CT angiography (CTA) after endovascular aortic repair (EVAR). Materials and Methods In this single-center prospective randomized controlled trial, individuals undergoing CTA after EVAR between August 2020 and May 2022 were allocated to imaging using either low-kilovolt single-energy images (SEI; 80 kV, group A) or low-kiloelectron volt virtual monoenergetic images (VMI) at 40 and 50 keV from multi-energy CT (80/Sn150 kV, group B). Scan protocols were dose matched (volume CT dose index: mean, 4.5 mGy ± 1.8 [SD] vs 4.7 mGy ± 1.3, P = .41). Contrast-to-noise ratio (CNR) was measured. Two expert radiologists established the reference standard for the presence of endoleaks. Detection and conspicuity of endoleaks and subjective image quality were assessed by two different blinded radiologists. Interreader agreement was calculated. Nonparametric statistical tests were used. Results A total of 125 participants (mean age, 76 years ± 8; 103 men) were allocated to groups A (n = 64) and B (n = 61). CNR was significantly lower for 40-keV VMI (mean, 19.1; P = .048) and 50-keV VMI (mean, 16.8; P < .001) as compared with SEI (mean, 22.2). In total, 45 endoleaks were present (A: 23 vs B: 22). Sensitivity for endoleak detection was higher for SEI (82.6%, 19 of 23; P = .88) and 50-keV VMI (81.8%, 18 of 22; P = .90) as compared with 40-keV VMI (77.3%, 17 of 22). Specificity was comparable among groups (SEI: 92.7%, 38 of 41; both VMI energies: 92.3%, 35 of 38; P = .99), with an interreader agreement of 1. Conspicuity of endoleaks was comparable between SEI (median, 2.99) and VMI (both energies: median, 2.87; P = .04). Overall subjective image quality was rated significantly higher for SEI (median, 4 [IQR, 4-4) as compared with 40 and 50 keV (both energies: median, 4 [IQR, 3-4]; P < .001). Conclusion SEI demonstrated higher image quality and comparable diagnostic accuracy as compared with 50-keV VMI for endoleak detection at CTA after EVAR. Keywords: Aneurysms, CT, CT Angiography, Vascular, Aorta, Technology Assessment, Multidetector CT, Abdominal Aortic Aneurysms, Endoleaks, Perigraft Leak Supplemental material is available for this article. © RSNA, 2024.
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Affiliation(s)
- Anna Landsmann
- From the Department of Diagnostic and Interventional Radiology,
University Hospital Zurich, University of Zurich, Rämistrasse 100, 8091
Zurich, Switzerland (A.L., T.S., V.M., L.J., M.E., A.K., H.A., A.E.); Department
of Radiology, Spital Interlaken, Spitäler fmi AG, Unterseen, Switzerland
(M.E.); and Department of Radiology, Kantonsspital Baden, Baden, Switzerland
(A.E.)
| | - Thomas Sartoretti
- From the Department of Diagnostic and Interventional Radiology,
University Hospital Zurich, University of Zurich, Rämistrasse 100, 8091
Zurich, Switzerland (A.L., T.S., V.M., L.J., M.E., A.K., H.A., A.E.); Department
of Radiology, Spital Interlaken, Spitäler fmi AG, Unterseen, Switzerland
(M.E.); and Department of Radiology, Kantonsspital Baden, Baden, Switzerland
(A.E.)
| | - Victor Mergen
- From the Department of Diagnostic and Interventional Radiology,
University Hospital Zurich, University of Zurich, Rämistrasse 100, 8091
Zurich, Switzerland (A.L., T.S., V.M., L.J., M.E., A.K., H.A., A.E.); Department
of Radiology, Spital Interlaken, Spitäler fmi AG, Unterseen, Switzerland
(M.E.); and Department of Radiology, Kantonsspital Baden, Baden, Switzerland
(A.E.)
| | - Lisa Jungblut
- From the Department of Diagnostic and Interventional Radiology,
University Hospital Zurich, University of Zurich, Rämistrasse 100, 8091
Zurich, Switzerland (A.L., T.S., V.M., L.J., M.E., A.K., H.A., A.E.); Department
of Radiology, Spital Interlaken, Spitäler fmi AG, Unterseen, Switzerland
(M.E.); and Department of Radiology, Kantonsspital Baden, Baden, Switzerland
(A.E.)
| | - Matthias Eberhard
- From the Department of Diagnostic and Interventional Radiology,
University Hospital Zurich, University of Zurich, Rämistrasse 100, 8091
Zurich, Switzerland (A.L., T.S., V.M., L.J., M.E., A.K., H.A., A.E.); Department
of Radiology, Spital Interlaken, Spitäler fmi AG, Unterseen, Switzerland
(M.E.); and Department of Radiology, Kantonsspital Baden, Baden, Switzerland
(A.E.)
| | - Adrian Kobe
- From the Department of Diagnostic and Interventional Radiology,
University Hospital Zurich, University of Zurich, Rämistrasse 100, 8091
Zurich, Switzerland (A.L., T.S., V.M., L.J., M.E., A.K., H.A., A.E.); Department
of Radiology, Spital Interlaken, Spitäler fmi AG, Unterseen, Switzerland
(M.E.); and Department of Radiology, Kantonsspital Baden, Baden, Switzerland
(A.E.)
| | - Hatem Alkadhi
- From the Department of Diagnostic and Interventional Radiology,
University Hospital Zurich, University of Zurich, Rämistrasse 100, 8091
Zurich, Switzerland (A.L., T.S., V.M., L.J., M.E., A.K., H.A., A.E.); Department
of Radiology, Spital Interlaken, Spitäler fmi AG, Unterseen, Switzerland
(M.E.); and Department of Radiology, Kantonsspital Baden, Baden, Switzerland
(A.E.)
| | - André Euler
- From the Department of Diagnostic and Interventional Radiology,
University Hospital Zurich, University of Zurich, Rämistrasse 100, 8091
Zurich, Switzerland (A.L., T.S., V.M., L.J., M.E., A.K., H.A., A.E.); Department
of Radiology, Spital Interlaken, Spitäler fmi AG, Unterseen, Switzerland
(M.E.); and Department of Radiology, Kantonsspital Baden, Baden, Switzerland
(A.E.)
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Pannenbecker P, Heidenreich JF, Grunz JP, Huflage H, Gruschwitz P, Patzer TS, Feldle P, Bley TA, Petritsch B. Image Quality and Radiation Dose of CTPA With Iodine Maps: A Prospective Randomized Study of High-Pitch Mode Photon-Counting Detector CT Versus Energy-Integrating Detector CT. AJR Am J Roentgenol 2024; 222:e2330154. [PMID: 37966036 DOI: 10.2214/ajr.23.30154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2023]
Abstract
BACKGROUND. Dual-energy CT pulmonary angiography (CTPA) with energy-integrating detector (EID) technology is limited by the inability to use high-pitch technique. OBJECTIVE. The purpose of this study was to compare the image quality of anatomic images and iodine maps between high-pitch photon-counting detector (PCD) CTPA and dual-energy EID CTPA. METHODS. This prospective study included 117 patients (70 men and 47 women; median age, 65 years) who underwent CTPA to evaluate for pulmonary embolism between March 2022 and November 2022. Fifty-eight patients were randomized to undergo PCD CTPA (pitch, 2.0), and 59 were randomized to undergo EID CTPA (pitch, 0.55). For each examination, 120-kV polychromatic images, 60-keV virtual monogenetic images (VMIs), and iodine maps were reconstructed. One radiologist measured CNR and SNR. Three radiologists independently assessed subjective image quality (on a scale of 1-4, with a score of 1 denoting highest quality). Radiation dose was recorded. RESULTS. SNR and CNR were higher for PCD CTPA than for EID CTPA for polychromatic images and VMIs, for all assessed vessels other than the left upper lobe artery. For example, for PCD CTPA versus EID CTPA, the right lower lobe artery on polychromatic images had an SNR of 34.5 versus 28.0 (p = .003) and a CNR of 29.2 versus 24.4 (p = .001), and on VMIs it had an SNR of 43.2 versus 32.7 (p = .005) and a CNR of 37.4 versus 29.3 (p = .002). For both scanners for readers 1 and 2, the median image quality score for polychromatic images and VMIs was 1, although distributions indicated significantly better scores for PCD CTPA than for EID CTPA for polychromatic images for reader 1 (p = .02) and reader 2 (p = .005) and for VMIs for reader 1 (p = .001) and reader 2 (p = .006). The image quality of anatomic image sets was not different between PCD CTPA and EID CTPA for reader 3 (p > .05). The image quality of iodine maps was not different between PCD CTPA and EID CTPA for any reader (p > .05). For PCD CTPA versus EID CTPA, the CTDIvol was 3.9 versus 4.5 mGy (p = .03), and the DLP was 123.5 mGy × cm versus 157.0 mGy × cm (p < .001). CONCLUSION. High-pitch PCD CTPA provided anatomic images with better subjective and objective image quality versus dual-energy EID CTPA, with lower radiation dose. Iodine maps showed no significant difference in image quality between scanners. CLINICAL IMPACT. CTPA may benefit from the PCD CT technique.
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Affiliation(s)
- Pauline Pannenbecker
- Department of Diagnostic Radiology and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstrasse, 6, D-97080 Würzburg, Germany
| | - Julius F Heidenreich
- Department of Diagnostic Radiology and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstrasse, 6, D-97080 Würzburg, Germany
| | - Jan-Peter Grunz
- Department of Diagnostic Radiology and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstrasse, 6, D-97080 Würzburg, Germany
| | - Henner Huflage
- Department of Diagnostic Radiology and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstrasse, 6, D-97080 Würzburg, Germany
| | - Philipp Gruschwitz
- Department of Diagnostic Radiology and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstrasse, 6, D-97080 Würzburg, Germany
| | - Theresa S Patzer
- Department of Diagnostic Radiology and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstrasse, 6, D-97080 Würzburg, Germany
| | - Philipp Feldle
- Department of Diagnostic Radiology and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstrasse, 6, D-97080 Würzburg, Germany
| | - Thorsten A Bley
- Department of Diagnostic Radiology and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstrasse, 6, D-97080 Würzburg, Germany
| | - Bernhard Petritsch
- Department of Diagnostic Radiology and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstrasse, 6, D-97080 Würzburg, Germany
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Langius-Wiffen E, Nijholt IM, van Dijk RA, de Boer E, Nijboer-Oosterveld J, Veldhuis WB, de Jong PA, Boomsma MF. An artificial intelligence algorithm for pulmonary embolism detection on polychromatic computed tomography: performance on virtual monochromatic images. Eur Radiol 2024; 34:384-390. [PMID: 37542651 DOI: 10.1007/s00330-023-10048-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 06/19/2023] [Accepted: 06/22/2023] [Indexed: 08/07/2023]
Abstract
OBJECTIVES Virtual monochromatic images (VMI) are increasingly used in clinical practice as they improve contrast-to-noise ratio. However, due to their different appearances, the performance of artificial intelligence (AI) trained on conventional CT images may worsen. The goal of this study was to assess the performance of an established AI algorithm trained on conventional polychromatic computed tomography (CT) images (CPI) to detect pulmonary embolism (PE) on VMI. METHODS Paired 60 kiloelectron volt (keV) VMI and CPI of 114 consecutive patients suspected of PE, obtained with a detector-based spectral CT scanner, were retrospectively analyzed by an established AI algorithm. The CT pulmonary angiography (CTPA) were classified as positive or negative for PE on a per-patient level. The reference standard was established using a comprehensive method that combined the evaluation of the attending radiologist and three experienced cardiothoracic radiologists aided by two different detection tools. Sensitivity, specificity, positive and negative predictive values and likelihood ratios of the algorithm on VMI and CPI were compared. RESULTS The prevalence of PE according to the reference standard was 35.1% (40 patients). None of the diagnostic accuracy measures of the algorithm showed a significant difference between CPI and VMI. Sensitivity was 77.5% (95% confidence interval (CI) 64.6-90.4%) and 85.0% (73.9-96.1%) (p = 0.08) on CPI and VMI respectively and specificity 96.0% (91.4-100.0%) and 94.6% (89.4-99.7%) (p = 0.32). CONCLUSIONS Diagnostic performance of the AI algorithm that was trained on CPI did not drop on VMI, which is reassuring for its use in clinical practice. CLINICAL RELEVANCE STATEMENT A commercially available AI algorithm, trained on conventional polychromatic CTPA, could be safely used on virtual monochromatic images. This supports the sustainability of AI-aided detection of PE on CT despite ongoing technological advances in medical imaging, although monitoring in daily practice will remain important. KEY POINTS • Diagnostic accuracy of an AI algorithm trained on conventional polychromatic images to detect PE did not drop on virtual monochromatic images. • Our results are reassuring as innovations in hardware and reconstruction in CT are continuing, whilst commercial AI algorithms that are trained on older generation data enter healthcare.
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Affiliation(s)
- Eline Langius-Wiffen
- Department of Radiology, Isala Hospital, Dr. Van Heesweg 2, 8025 AB, Zwolle, The Netherlands.
| | - Ingrid M Nijholt
- Department of Radiology, Isala Hospital, Dr. Van Heesweg 2, 8025 AB, Zwolle, The Netherlands
| | - Rogier A van Dijk
- Department of Radiology, Isala Hospital, Dr. Van Heesweg 2, 8025 AB, Zwolle, The Netherlands
| | - Erwin de Boer
- Department of Radiology, Isala Hospital, Dr. Van Heesweg 2, 8025 AB, Zwolle, The Netherlands
| | | | - Wouter B Veldhuis
- Department of Radiology, University Medical Centre Utrecht, Utrecht, the Netherlands
| | - Pim A de Jong
- Department of Radiology, University Medical Centre Utrecht, Utrecht, the Netherlands
| | - Martijn F Boomsma
- Department of Radiology, Isala Hospital, Dr. Van Heesweg 2, 8025 AB, Zwolle, The Netherlands
- Division of Imaging and Oncology, University Medical Centre Utrecht, Utrecht, The Netherlands
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Pannenbecker P, Huflage H, Grunz JP, Gruschwitz P, Patzer TS, Weng AM, Heidenreich JF, Bley TA, Petritsch B. Photon-counting CT for diagnosis of acute pulmonary embolism: potential for contrast medium and radiation dose reduction. Eur Radiol 2023; 33:7830-7839. [PMID: 37311805 PMCID: PMC10598187 DOI: 10.1007/s00330-023-09777-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 04/07/2023] [Accepted: 04/11/2023] [Indexed: 06/15/2023]
Abstract
OBJECTIVE To evaluate the image quality of an ultra-low contrast medium and radiation dose CT pulmonary angiography (CTPA) protocol for the diagnosis of acute pulmonary embolism using a clinical photon-counting detector (PCD) CT system and compare its performance to a dual-energy-(DE)-CTPA protocol on a conventional energy-integrating detector (EID) CT system. METHODS Sixty-four patients either underwent CTPA with the novel scan protocol on the PCD-CT scanner (32 patients, 25 mL, CTDIvol 2.5 mGy·cm) or conventional DE-CTPA on a third-generation dual-source EID-CT (32 patients, 50 mL, CTDIvol 5.1 mGy·cm). Pulmonary artery CT attenuation, signal-to-noise ratio, and contrast-to-noise-ratio were assessed as objective criteria of image quality, while subjective ratings of four radiologists were compared at 60 keV using virtual monoenergetic imaging and polychromatic standard reconstructions. Interrater reliability was determined by means of the intraclass correlation coefficient (ICC). Effective dose was compared between patient cohorts. RESULTS Subjective image quality was deemed superior by all four reviewers for 60-keV PCD scans (excellent or good ratings in 93.8% of PCD vs. 84.4% of 60 keV EID scans, ICC = 0.72). No examinations on either system were considered "non-diagnostic." Objective image quality parameters were significantly higher in the EID group (mostly p < 0.001), both in the polychromatic reconstructions and at 60 keV. The ED (1.4 vs. 3.3 mSv) was significantly lower in the PCD cohort (p < 0.001). CONCLUSIONS PCD-CTPA allows for considerable reduction of contrast medium and radiation dose in the diagnosis of acute pulmonary embolism, while maintaining good to excellent image quality compared to conventional EID-CTPA. CLINICAL RELEVANCE STATEMENT Clinical PCD-CT allows for spectral assessment of pulmonary vasculature with high scan speed, which is beneficial in patients with suspected pulmonary embolism, frequently presenting with dyspnea. Simultaneously PCD-CT enables substantial reduction of contrast medium and radiation dose. KEY POINTS • The clinical photon-counting detector CT scanner used in this study allows for high-pitch multi-energy acquisitions. • Photon-counting computed tomography allows for considerable reduction of contrast medium and radiation dose in the diagnosis of acute pulmonary embolism. • Subjective image quality was rated best for 60-keV photon-counting scans.
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Affiliation(s)
- Pauline Pannenbecker
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstr. 6, D-97080, Würzburg, Germany.
| | - Henner Huflage
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstr. 6, D-97080, Würzburg, Germany
| | - Jan-Peter Grunz
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstr. 6, D-97080, Würzburg, Germany
| | - Philipp Gruschwitz
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstr. 6, D-97080, Würzburg, Germany
| | - Theresa S Patzer
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstr. 6, D-97080, Würzburg, Germany
| | - Andreas M Weng
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstr. 6, D-97080, Würzburg, Germany
| | - Julius F Heidenreich
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstr. 6, D-97080, Würzburg, Germany
| | - Thorsten A Bley
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstr. 6, D-97080, Würzburg, Germany
| | - Bernhard Petritsch
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacherstr. 6, D-97080, Würzburg, Germany
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Abstract
Dual-energy CT has expanded the potential of thoracic imaging in both children and adults. Data processing allows material- and energy-specific reconstructions, which improve material differentiation and tissue characterization compared with single-energy CT. Material-specific reconstructions include iodine, virtual unenhanced, perfusion blood volume, and lung vessel images, which can improve assessment of vascular, mediastinal, and parenchymal abnormalities. The energy-specific reconstruction algorithm allows virtual monoenergetic reconstructions, including low-energy images to increase iodine conspicuity and high-energy images to reduce beam-hardening and metal artifacts. This review highlights dual-energy CT principles, hardware, and postprocessing algorithms; the clinical applications of dual-energy CT; and the potential benefits of photon counting (the most recently introduced iteration of spectral imaging) in pediatric thoracic imaging.
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Affiliation(s)
- Jordan B Rapp
- Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, PA
| | - David M Biko
- Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, PA
| | - Marilyn J Siegel
- Edward Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 S Kingshighway Blvd, St. Louis, MO 63110
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Gembillo G, Calimeri S, Tranchida V, Silipigni S, Vella D, Ferrara D, Spinella C, Santoro D, Visconti L. Lung Dysfunction and Chronic Kidney Disease: A Complex Network of Multiple Interactions. J Pers Med 2023; 13:jpm13020286. [PMID: 36836520 PMCID: PMC9966880 DOI: 10.3390/jpm13020286] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/29/2023] [Accepted: 02/01/2023] [Indexed: 02/05/2023] Open
Abstract
Chronic kidney disease (CKD) is a progressive disease that affects > 10% of the total population worldwide or >800 million people. CKD poses a particularly heavy burden in low- and middle-income countries, which are least able to cope with its consequences. It has become one of the leading causes of death worldwide and is one of the few non-communicable diseases where the number of related deaths has increased over the last two decades. The high number of people affected, and the significant negative impact of CKD should be a reason to increase efforts to improve prevention and treatment. The interaction of lung and kidney leads to highly complex and difficult clinical scenarios. CKD significantly affects the physiology of the lung by altering fluid homeostasis, acid-base balance and vascular tone. In the lung, haemodynamic disturbances lead to the development of alterations in ventilatory control, pulmonary congestion, capillary stress failure and pulmonary vascular disease. In the kidney, haemodynamic disturbances lead to sodium and water retention and the deterioration of renal function. In this article, we would like to draw attention to the importance of harmonising the definitions of clinical events in pneumology and renal medicine. We would also like to highlight the need for pulmonary function tests in routine clinical practise for the management of patients with CKD, in order to find new concepts for pathophysiological based disease-specific management strategies.
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Affiliation(s)
- Guido Gembillo
- Unit of Nephrology and Dialysis, Department of Clinical and Experimental Medicine, University of Messina, 98125 Messina, Italy
- Department of Biomedical and Dental Sciences and Morpho-Functional Imaging, University of Messina, 98125 Messina, Italy
- Correspondence: ; Tel.: +39-00902212265
| | - Sebastiano Calimeri
- Unit of Nephrology and Dialysis, Ospedali Riuniti Villa Sofia Cervello, University of Palermo, 90146 Palermo, Italy
| | - Valeria Tranchida
- Unit of Nephrology and Dialysis, Ospedali Riuniti Villa Sofia Cervello, University of Palermo, 90146 Palermo, Italy
| | - Salvatore Silipigni
- Department of Biomedical Sciences and Morphologic and Functional Imaging, Policlinico “G. Martino’’, University of Messina, Via Consolare Valeria 1, 98100 Messina, Italy
| | - Davide Vella
- Unit of Nephrology and Dialysis, Ospedali Riuniti Villa Sofia Cervello, University of Palermo, 90146 Palermo, Italy
| | - Domenico Ferrara
- Unit of Nephrology and Dialysis, Ospedali Riuniti Villa Sofia Cervello, University of Palermo, 90146 Palermo, Italy
| | - Claudia Spinella
- Unit of Nephrology and Dialysis, Department of Clinical and Experimental Medicine, University of Messina, 98125 Messina, Italy
| | - Domenico Santoro
- Unit of Nephrology and Dialysis, Department of Clinical and Experimental Medicine, University of Messina, 98125 Messina, Italy
| | - Luca Visconti
- Unit of Nephrology and Dialysis, Ospedali Riuniti Villa Sofia Cervello, University of Palermo, 90146 Palermo, Italy
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Value of low-keV virtual monoenergetic plus dual-energy computed tomographic imaging for detection of acute pulmonary embolism. PLoS One 2022; 17:e0277060. [DOI: 10.1371/journal.pone.0277060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 10/19/2022] [Indexed: 11/13/2022] Open
Abstract
Objective
To compare diagnostic values between the 40 keV virtual monoenergetic plus (40 keV VMI+) dual source dual energy computed tomography (DSDECT) pulmonary angiography images and the standard mixed (90 and 150 kV) images for the detection of acute pulmonary embolism (PE).
Methods
Chest DSDECTs of 64 patients who were suspected of having acute PE were retrospectively reviewed by two independent reviewers. The assessments of acute PE of all patients on a per-location basis were compared between the 40 keV VMI+ and the standard mixed datasets (reference standard) with a two-week interval.
Results
This study consisted of 64 patients (33 women and 31 men; mean age, 60.2 years; range 18–90 years), with a total of 512 locations. The interobserver agreement (Kappa) for detection of acute PE using the 40 keV VMI+ images and the standard mixed CT images were 0.7478 and 0.8750 respectively. The area under receiver operating characteristics (AuROC) for diagnosis of acute PE using the 40 keV VMI+ was 0.882. Four locations (0.78%) revealed a false negative result. Hypodense filling defects were identified in twelve locations (1.95%) in the 40 keV VMI+ images but had been interpreted as a negative study in the standard mixed CT images. The repeated reviews revealed that each location contained a hypodense filling defect but was overlooked on the standard mixed CT images.
Conclusions
Low-energy VMI + DSDECT images have beneficial in improving the diagnostic value of acute PE in doubtful or disregarded standard mixed images.
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Yalynska T, Polacin M, Frauenfelder T, Martini K. Impact of Photon Counting Detector CT Derived Virtual Monoenergetic Images on the Diagnosis of Pulmonary Embolism. Diagnostics (Basel) 2022; 12:diagnostics12112715. [PMID: 36359558 PMCID: PMC9689164 DOI: 10.3390/diagnostics12112715] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 11/01/2022] [Accepted: 11/03/2022] [Indexed: 11/09/2022] Open
Abstract
Purpose: To assess the impact of virtual-monoenergetic-image (VMI) energies on the diagnosis of pulmonary embolism (PE) in photon-counting-detector computed-tomography (PCD-CT). Methods: Eighty patients (median age 60.4 years) with suspected PE were retrospectively included. Scans were performed on PCD-CT in the multi-energy mode at 120 kV. VMIs from 40−70 keV in 10 keV intervals were reconstructed. CT-attenuation was measured in the pulmonary trunk and the main branches of the pulmonary artery. Signal-to-noise (SNR) ratio was calculated. Two radiologists evaluated subjective-image-quality (noise, vessel-attenuation and sharpness; five-point-Likert-scale, non-diagnostic−excellent), the presence of hardening artefacts and presence/visibility of PE. Results: Signal was highest at the lowest evaluated VMI (40 keV; 1053.50 HU); image noise was lowest at the highest VMI (70 keV; 15.60 HU). Highest SNR was achieved at the lowest VMI (p < 0.05). Inter-reader-agreement for subjective analysis was fair to excellent (k = 0.373−1.000; p < 0.001). Scores for vessel-attenuation and sharpness were highest at 40 keV (both:5, range 4/3−5; k = 1.000); scores for image-noise were highest at 70 keV (4, range 3−5). The highest number of hardening artifacts were reported at 40 keV (n = 22; 28%). PE-visualization was rated best at 50 keV (4.7; range 4−5) and decreased with increasing VMI-energy (r = −0.558; p < 0.001). Conclusions: While SNR was best at 40 keV, subjective PE visibility was rated highest at 50 keV, potentially owing to the lower image noise and hardening artefacts.
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Li Y, Younis MH, Wang H, Zhang J, Cai W, Ni D. Spectral computed tomography with inorganic nanomaterials: State-of-the-art. Adv Drug Deliv Rev 2022; 189:114524. [PMID: 36058350 PMCID: PMC9664656 DOI: 10.1016/j.addr.2022.114524] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 08/09/2022] [Accepted: 08/27/2022] [Indexed: 01/24/2023]
Abstract
Recently, spectral computed tomography (CT) technology has received great interest in the field of radiology. Spectral CT imaging utilizes the distinct, energy-dependent X-ray absorption properties of substances in order to provide additional imaging information. Dual-energy CT and multi-energy CT (Spectral CT) are capable of constructing monochromatic energy images, material separation images, energy spectrum curves, constructing effective atomic number maps, and more. However, poor contrast, due to neighboring X-ray attenuation of organs and tissues, is still a challenge to spectral CT. Hence, contrast agents (CAs) are applied for better differentiation of a given region of interest (ROI). Currently, many different kinds of inorganic nanoparticulate CAs for spectral CT have been developed due to the limitations of clinical iodine (I)-based contrast media, leading to the conclusion that inorganic nanomedicine applied to spectral CT will be a powerful collaboration both in basic research and in clinics. In this review, the underlying principles and types of spectral CT techniques are discussed, and some evolving clinical diagnosis applications of spectral CT techniques are introduced. In particular, recent developments in inorganic CAs used for spectral CT are summarized. Finally, the challenges and future developments of inorganic nanomedicine in spectral CT are briefly discussed.
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Affiliation(s)
- Yuhan Li
- School of Medicine, Shanghai University, No. 99 Shangda Rd, Shanghai 200444, PR China
| | - Muhsin H Younis
- Departments of Radiology and Medical Physics, University of Wisconsin-Madison, WI 53705, United States
| | - Han Wang
- Department of Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopaedics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197, Ruijin 2nd Rd, Shanghai 200025, PR China
| | - Jian Zhang
- School of Medicine, Shanghai University, No. 99 Shangda Rd, Shanghai 200444, PR China; Shanghai Universal Medical Imaging Diagnostic Center, Bldg 8, No. 406 Guilin Rd, Shanghai 200233, PR China.
| | - Weibo Cai
- Departments of Radiology and Medical Physics, University of Wisconsin-Madison, WI 53705, United States.
| | - Dalong Ni
- Department of Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopaedics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197, Ruijin 2nd Rd, Shanghai 200025, PR China.
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Toia GV, Mileto A, Wang CL, Sahani DV. Quantitative dual-energy CT techniques in the abdomen. Abdom Radiol (NY) 2022; 47:3003-3018. [PMID: 34468796 DOI: 10.1007/s00261-021-03266-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 08/25/2021] [Accepted: 08/26/2021] [Indexed: 02/06/2023]
Abstract
Advances in dual-energy CT (DECT) technology and spectral techniques are catalyzing the widespread implementation of this technology across multiple radiology subspecialties. The inclusion of energy- and material-specific datasets has ushered overall improvements in CT image contrast and noise as well as artifacts reduction, leading to considerable progress in radiologists' ability to detect and characterize pathologies in the abdomen. The scope of this article is to provide an overview of various quantitative clinical DECT applications in the abdomen and pelvis. Several of the reviewed applications have not reached mainstream clinical use and are considered investigational. Nonetheless awareness of such applications is critical to having a fully comprehensive knowledge base to DECT and fostering future clinical implementation.
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Affiliation(s)
- Giuseppe V Toia
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, 600 Highland Avenue, Mailbox 3252, Madison, WI, 53792, USA.
| | - Achille Mileto
- Department of Radiology, Mayo Clinic, 200 First Street, SW, Rochester, MN, 55905, USA
| | - Carolyn L Wang
- Department of Radiology, University of Washington School of Medicine, 1959 NE Pacific Street, Seattle, WA, 98195, USA
| | - Dushyant V Sahani
- Department of Radiology, University of Washington School of Medicine, 1959 NE Pacific Street, Seattle, WA, 98195, USA
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Abdellatif W, Vasan V, Kay FU, Kohli A, Abbara S, Brewington C. Know your way around acute unenhanced CT during global iodinated contrast crisis: a refresher to ED radiologists. Emerg Radiol 2022; 29:1019-1031. [PMID: 35945464 PMCID: PMC9363271 DOI: 10.1007/s10140-022-02085-7] [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: 06/12/2022] [Accepted: 08/02/2022] [Indexed: 11/30/2022]
Abstract
Due to a contrast shortage crisis resulting from the decreased supply of iodinated contrast agents, the American College of Radiology (ACR) has issued a guidance statement followed by memoranda from various hospitals to preserve and prioritize the limited supply of contrast. The vast majority of iodinated contrast is used by CT, with a minority used by vascular and intervention radiology, fluoroscopy, and other services. A direct consequence is a paradigm shift to large volume unenhanced CT scans being utilized for acute and post traumatic patients in EDs, an uncharted territory for most radiologists and trainees. This article provides radiological diagnostic guidance and a pictorial example through systematic review of common unenhanced CT findings in the acute setting.
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Affiliation(s)
- Waleed Abdellatif
- Department of Radiology, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-8896, USA.
| | - Vasantha Vasan
- Abdominal Imaging Division, Department of Radiology, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-8896, USA
| | - Fernando U Kay
- Cardiothoracic Imaging Division, Department of Radiology, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-8896, USA
| | - Ajay Kohli
- Departments of Radiology and Orthopedic Surgery, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-8896, USA
| | - Suhny Abbara
- Cardiothoracic Imaging Division, Department of Radiology, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-8896, USA
| | - Cecelia Brewington
- Department of Radiology, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-8896, USA
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Jointly Optimized Deep Neural Networks to Synthesize Monoenergetic Images from Single-Energy CT Angiography for Improving Classification of Pulmonary Embolism. Diagnostics (Basel) 2022; 12:diagnostics12051224. [PMID: 35626379 PMCID: PMC9141232 DOI: 10.3390/diagnostics12051224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 04/30/2022] [Accepted: 05/09/2022] [Indexed: 02/04/2023] Open
Abstract
Detector-based spectral CT offers the possibility of obtaining spectral information from which discrete acquisitions at different energy levels can be derived, yielding so-called virtual monoenergetic images (VMI). In this study, we aimed to develop a jointly optimized deep-learning framework based on dual-energy CT pulmonary angiography (DE-CTPA) data to generate synthetic monoenergetic images (SMI) for improving automatic pulmonary embolism (PE) detection in single-energy CTPA scans. For this purpose, we used two datasets: our institutional DE-CTPA dataset D1, comprising polyenergetic arterial series and the corresponding VMI at low-energy levels (40 keV) with 7892 image pairs, and a 10% subset of the 2020 RSNA Pulmonary Embolism CT Dataset D2, which consisted of 161,253 polyenergetic images with dichotomous slice-wise annotations (PE/no PE). We trained a fully convolutional encoder-decoder on D1 to generate SMI from single-energy CTPA scans of D2, which were then fed into a ResNet50 network for training of the downstream PE classification task. The quantitative results on the reconstruction ability of our framework revealed high-quality visual SMI predictions with reconstruction results of 0.984 ± 0.002 (structural similarity) and 41.706 ± 0.547 dB (peak signal-to-noise ratio). PE classification resulted in an AUC of 0.84 for our model, which achieved improved performance compared to other naïve approaches with AUCs up to 0.81. Our study stresses the role of using joint optimization strategies for deep-learning algorithms to improve automatic PE detection. The proposed pipeline may prove to be beneficial for computer-aided detection systems and could help rescue CTPA studies with suboptimal opacification of the pulmonary arteries from single-energy CT scanners.
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13
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Dual-layer spectral detector CT for contrast agent concentration, dose and injection rate reduction: Utility in imaging of the superior mesenteric artery. Eur J Radiol 2022; 150:110246. [DOI: 10.1016/j.ejrad.2022.110246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 02/12/2022] [Accepted: 03/07/2022] [Indexed: 11/20/2022]
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Initial Investigation of Clinical Value of Noise-Optimized Virtual Monoenergetic Images Derived From Dual-Energy Computed Tomography Angiography in Preoperative Perforator Planning of Anterolateral Thigh Flap Transplantation. J Comput Assist Tomogr 2022; 46:560-567. [PMID: 35405721 DOI: 10.1097/rct.0000000000001320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVE To objectively and subjectively assess the image characteristics of noise-optimized virtual monoenergetic images [MEI (+)] and polyenergetic images (PEIs) from dual-energy computed tomography angiography and then to explore the clinical value of the optimal MEI (+) in preoperative perforator planning of anterolateral thigh (ALT) flap transplantation. METHODS Sixteen patients (32 thighs) who underwent lower extremity run-off dual-energy computed tomography angiography for planning ALT flap transplantation were enrolled. One standard PEI and 5 MEI (+) in 10-keV intervals (range, 40-80 keV) were reconstructed. First, we compared the image quality subjectively (branch order, image quality, and vascular network continuity) and objectively (vascular attenuation, image noise, signal-to-noise ratio, and the contrast-to-noise ratio). Then, we compared the clinical value (number, type, source artery, pedicle length, caliber, and location of all sizable perforators) between the optimal MEI (+) and PEI groups. RESULTS The 40-keV MEI (+) was rated superior subjective and objective image quality metrics to PEI (all P < 0.001). Compared with PEI, 40 keV MEI (+) increased the number of visible perforators, the percentage of perforators with identifiable types, and the measurable length of perforator pedicle (all P < 0.001). CONCLUSIONS We recommend 40 keV MEI (+) for the visualization of perforators and their contribution to the selection and location of suitable perforators in preoperative planning for ALT flaps.
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Chen L, Zhu M, Lu H, Yang T, Li W, Zhang Y, Xie Q, Li Z, Wan H, Luo F. Quantitative evaluation of disease severity in connective tissue disease-associated interstitial lung disease by dual-energy computed tomography. Respir Res 2022; 23:47. [PMID: 35248040 PMCID: PMC8897904 DOI: 10.1186/s12931-022-01972-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 02/24/2022] [Indexed: 11/16/2022] Open
Abstract
Background High-resolution computed tomography (HRCT) is recommended diagnosing and monitoring connective tissue disease-associated interstitial lung disease (CTD-ILD). Quantitative computed tomography has the potential to precisely assess the radiological severity of CTD-ILD, but has still been under study. Objective To investigate whether dual-energy computed tomography (DECT), a novel quantitative technique, can be used for quantitative severity assessment in CTD-ILD. Methods This cross sectional study recruited adult CTD-ILD patients who underwent DECT scans from the ICE study between October 2019 and November 2021. DECT parameters, including effective atomic number (Zeff), lung (lobe) volume, and monochromatic CT number (MCTN) of each lung lobe, were evaluated. CTD-ILD was classified into extensive CTD-ILD and limited CTD-ILD by staging algorithm using combined forced vital capacity (FVC)%predicted and total extent of ILD (TEI) on CT. Dyspnea, cough, and life quality were scored by Borg dyspnea score, Leicester cough questionnaire (LCQ), and short-form 36 health survey questionnaire (SF-36), respectively. Results There was a total of 147 patients with DECT scans enrolled. Higher Zeff value (3.104 vs 2.256, p < 0.001), higher MCTN (− 722.87 HU vs − 802.20 HU, p < 0.001), and lower lung volume (2309.51cm3 vs 3475.21cm3, p < 0.001) were found in extensive CTD-ILD compared with limited CTD-ILD. DECT parameters had significant moderate correlations with FVC%predicted (|r|= 0.542–0.667, p < 0.01), DLCO%predicted (|r|= 0.371–0.427, p < 0.01), and TEI (|r|= 0.485–0.742, p < 0.01). Receiver operating characteristic (ROC) analysis indicated MCTN averaged over the whole lung had the best performance for extensive CTD-ILD discrimination (AUC = 0.901, cut-off: − 762.30 HU, p < 0.001), with a sensitivity of 82.1% and a specificity of 85.4%. The Zeff value was the independent risk factor for dyspnea (OR = 3.644, 95% CI: 1.846–7.192, p < 0.001) and cough (OR = 3.101, 95% CI: 1.528–6.294, p = 0.002), and lung volume significantly contributed to the mental component summary (MCS) in SF-36 (standardized β = 0.198, p < 0.05). Conclusions DECT can be applied to evaluate the severity of CTD-ILD. Supplementary Information The online version contains supplementary material available at 10.1186/s12931-022-01972-4.
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Impact of Contrast Enhancement and Virtual Monoenergetic Image Energy Levels on Emphysema Quantification. Invest Radiol 2022; 57:359-365. [DOI: 10.1097/rli.0000000000000848] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Chen J, Zhou J, Yang J, Cong R, Sun J, Xiao J, Shi J, He B. Efficiency of dual-energy computed tomography enterography in the diagnosis of Crohn's disease. BMC Med Imaging 2021; 21:185. [PMID: 34861843 PMCID: PMC8642845 DOI: 10.1186/s12880-021-00716-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 11/15/2021] [Indexed: 12/30/2022] Open
Abstract
Background This retrospective study aimed to investigate the usefulness of the optimized kiloelectron volt (keV) for virtual monoenergetic imaging (VMI) combined with iodine map in dual-energy computed tomography enterography (DECTE) in the diagnosis of Crohn’s disease (CD).
Methods Seventy-two patients (mean age: 41.89 ± 17.28 years) with negative computed tomography enterography (CTE) were enrolled for investigating the optimized VMI keV in DECTE by comparing subjective and objective parameters of VMIs that were reconstructed from 40 to 90 keV. Moreover, 68 patients (38.27 ± 15.10 years; 35 normal and 33 CD) were included for evaluating the diagnostic efficacy of DECTE iodine map at the optimized VMI energy level and routine CTE for CD and active CD. Statistical analysis for all data was conducted.
Results Objective and subjective imaging evaluations showed the best results at 60 keV for VMIs. The CT values of the normal group, active subgroup, and CD group during the small intestinal phase at routine 120 kVp or 60 keV VMI had significant differences. The diagnostic efficacy of an iodine map was the best when NIC = 4% or fat value = 45.8% for CD, whereas NIC < 0.35 or the fat value < 0.38 for active CD. The combined routine CTE and optimized VMI improved the diagnostic efficacy (P < 0.001). Conclusions VMI at 60 keV provided the best imaging quality on DECTE. NIC and fat value provided important basis for active CD evaluation. Routine CTE combined with VMI at 60 keV improved the diagnostic efficiency for CD. Supplementary Information The online version contains supplementary material available at 10.1186/s12880-021-00716-y.
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Affiliation(s)
- Jinghao Chen
- Department of Radiology, Affiliated Hospital 2 of Nantong University, Nantong City, 226001, Jiangsu Province, China
| | - Jie Zhou
- Department of Radiology, Affiliated Hospital 2 of Nantong University, Nantong City, 226001, Jiangsu Province, China.,Department of Radiology, Changzhou Hospital of Traditional Chinese Medicine, Changzhou City, 213000, Jiangsu Province, China
| | - Jushun Yang
- Department of Radiology, Affiliated Hospital 2 of Nantong University, Nantong City, 226001, Jiangsu Province, China
| | - Ruochen Cong
- Department of Radiology, Affiliated Hospital 2 of Nantong University, Nantong City, 226001, Jiangsu Province, China
| | - Jinjie Sun
- Gastrointestinal Surgery, Affiliated Hospital 2 of Nantong University, Nantong City, 226001, Jiangsu Province, China
| | - Jing Xiao
- Department of Epidemiology and Medical Statistics, School of Public Health, Nantong University, Nantong City, 226019, Jiangsu Province, China
| | - Jianhua Shi
- Department of Biochemistry, Nantong University Medical School, Nantong City, 226019, Jiangsu Province, China
| | - Bosheng He
- Department of Radiology, Affiliated Hospital 2 of Nantong University, Nantong City, 226001, Jiangsu Province, China. .,Clinical Medicine Research Center, Affiliated Hospital 2 of Nantong University, Nantong City, 226001, Jiangsu Province, China.
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Combination of Iterative Metal Artifact Reduction and Virtual Monoenergetic Reconstruction Using Split-Filter Dual-Energy CT in Patients With Dental Artifact on Head and Neck CT. AJR Am J Roentgenol 2021; 218:716-727. [PMID: 34755521 DOI: 10.2214/ajr.21.26772] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Background: Head and neck CT may be limited by dental hardware artifact. Both post-processing based iterative metal artifact reduction (iMAR) and virtual monoenergetic reconstruction (VMR) from dual-energy CT (DECT) can reduce metal artifact. Their combination is poorly described for single-source DECT systems. Objective: To compare metal artifact reduction between VMR, iMAR, and their combination, using split-filter single-source DECT in patients with severe dental hardware artifact. Methods: This retrospective study included 44 patients (9 female, 35 male; mean age 66.0±10.4 years) who underwent head and neck CT exhibiting severe dental hardware artifact. Standard images, VMR, iMAR, and VMRi-MAR were reconstructed; VMR and VMRiMAR used 40, 70, 100, 120, 150, and 190 keV. ROIs were placed to measure corrected attenuation in pronounced hyperattenuating and hypoattenuating artifacts and artifact-impaired soft tissue, as well as corrected artifact-impaired soft tissue noise. Two radiologists independently assessed soft tissue interpretability (1-5 scale); pooled ratings were analyzed. Readers selected the preferred reconstruction for each patient. Results: Mean hyperattenuating artifact corrected attenuation was 521.0 for standard, 496.4-892.2 for VMR, 48.2 for iMAR, and 32.8-91.0 for VMRiMAR. Mean hypoattenuating artifact corrected attenuation was -455.1 for standard, -408.5 to -679.9 for VMR, -37.3 for iMAR, and -17.8 to -36.9 for VMRiMAR. Mean artifact-impaired soft tissue corrected attenuation was 10.8 for standard, -0.6 to 24.9 for VMR, 4.3 for iMAR, and -2.0 to 7.8 for VMRiMAR. Mean artifact-impaired soft tissue corrected noise was 58.7 for standard, 38.2-129.7 for VMR, 11.0 for iMAR, and 5.8-45.6 for VMRiMAR. Median soft tissue interpretability was 1.2 for standard, 1.1-1.2 for VMR, 3.7 for iMAR, and 2.0-3.8 for VMRiMAR. Artifact-impaired soft tissue corrected attenuation and soft tissue interpretability were significantly improved (p<.05) for VMRiMAR versus iMAR only at 100 keV. Readers preferred VMRiMAR at 100 keV in 56.8% and 59.1% of examinations. Conclusion: For reducing severe dental material artifact, iMAR has greater impact than VMR. Though iMAR and VMRiMAR were overall similar, VMRiMAR exhibited small benefit at 100 keV. Clinical Impact: VMR and iMAR techniques, using split-filter DECT, may be combined for clinical head and neck imaging to reduce artifact from dental hardware and improve image quality.
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Zeng Y, Geng D, Zhang J. Noise-optimized virtual monoenergetic imaging technology of the third-generation dual-source computed tomography and its clinical applications. Quant Imaging Med Surg 2021; 11:4627-4643. [PMID: 34737929 DOI: 10.21037/qims-20-1196] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Accepted: 06/02/2021] [Indexed: 02/05/2023]
Abstract
The third-generation dual-source computed tomography (DSCT) is among the most advanced imaging methods. It employs noise-optimized virtual monoenergetic imaging (VMI+) technology. It uses the frequency-split method to extract high-contrast image information from low-energy images and low-noise information from images reconstructed at an optimal energy level, combining them to obtain the final image with improved quality. This review is the first to summarize the results of clinical studies that primarily and recently evaluated the VMI+ technique based on tumor, blood vessel, and other lesion classification. We aim to assist radiologists in quickly selecting the appropriate energy level when performing image reconstruction for superior image quality in clinical work and providing several ideas for future scientific research of the VMI+ technique. Presently, VMI+ reconstruction is mostly used for images of various tumors or blood vessels, including coronary plaques, coronary stents, deep vein thromboses, pulmonary embolisms (PEs), active arterial hemorrhages, and endoleaks after endovascular aneurysm repair. In addition, VMI+ has been used for imaging children's heads, liver lesions, pancreatic lacerations, and reducing metal artifacts. Regarding the reconstruction at the optimal energy level, the VMI+ technique yielded a higher image quality than the pre-optimized virtual monoenergetic imaging (VMI) technique and single-energy CT. Moreover, either low concentrations of contrast medium or low iodine injection rates can be applied before VMI+ reconstruction at a low-energy level to reduce contrast agent-related kidney injury risk. After reconstructing an image at the optimal energy level, both the image's window width and level can also be adjusted to improve the image effect's reach and diagnosis suitability. To improve image quality and lesion-imaging clarity and reduce the use of contrast agents, VMI+ reconstruction technology has been applied clinically, in which the selection of energy level is the key to the whole reconstruction process. Our review summarizes these optimal levels for radiologists' reference and suggests new ideas for the direction of future VMI+ research.
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Affiliation(s)
- Yanwei Zeng
- Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China.,Institute of Functional and Molecular Medical Imaging, Fudan University, Shanghai, China.,Center for Shanghai Intelligent Imaging for Critical Brain Diseases Engineering and Technology Research, Shanghai, China
| | - Daoying Geng
- Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China.,Institute of Functional and Molecular Medical Imaging, Fudan University, Shanghai, China.,Center for Shanghai Intelligent Imaging for Critical Brain Diseases Engineering and Technology Research, Shanghai, China
| | - Jun Zhang
- Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China.,Institute of Functional and Molecular Medical Imaging, Fudan University, Shanghai, China.,Center for Shanghai Intelligent Imaging for Critical Brain Diseases Engineering and Technology Research, Shanghai, China
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Kim GM, Choo KS, Kim JH, Hwang JY, Park CK, Lee JW, Lim SJ. Comparison of noise-optimized linearly blended images and noise-optimized virtual monoenergetic images evaluated by dual-source, dual-energy CT in cardiac vein assessment. Acta Radiol 2021; 62:594-602. [PMID: 32551805 DOI: 10.1177/0284185120933242] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The coronary venous system is frequently used as an entry route to the heart and treatment modalities for many cardiac diseases and many procedures. Consequently, evaluation of the coronary venous system and understanding cardiac vein anatomy is crucial. PURPOSE To determine the optimal image set in a comparison of noise-optimized linearly blended images (F_0.6) and noise-optimized virtual monoenergetic images (VMI+) evaluated by dual-energy computed tomography (DECT) for cardiac vein assessment. MATERIAL AND METHODS Thirty-four patients (mean age 58.2 ± 14.2 years) who underwent DECT due to chest pain were enrolled. Images were post-processed with the F_0.6, and VMI+ algorithms at energy levels in the range of 40-100 keV in 10-keV increments. Enhancement (HU), noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were objectively measured at two points in the great cardiac vein by consensus of two radiologists. Two blinded observers evaluated the subjective image quality of the great cardiac vein on a 4-point scale. RESULTS HU, noise, and SNR peaked at 40 keV VMI+ (P < 0.05) among 50-100 keV VMI+. CNR peaked at 100 keV VMI+; however, there were no significant differences compared to CNR images processed at 40-90 keV VMI+. HU and noise were significantly higher in 40 keV VMI+ than F_0.6 images; however, both SNR and CNR were significantly higher in F_0.6 images. An assessment of subjective vein delineation revealed that F_0.6 images had the highest scores. CONCLUSION F_0.6 images were superior to VMI+ and provided the optimal image set for cardiac vein assessment.
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Affiliation(s)
- Gyeong Min Kim
- Department of Radiology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Yangsan, Republic of Korea
| | - Ki Seok Choo
- Department of Radiology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Yangsan, Republic of Korea
| | - Jin Hyeok Kim
- Department of Radiology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Yangsan, Republic of Korea
| | - Jae-Yeon Hwang
- Department of Radiology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Yangsan, Republic of Korea
| | - Chan Kyu Park
- Department of Radiology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Yangsan, Republic of Korea
| | - Ji Won Lee
- Department of Radiology, Pusan National University Hospital, Busan, Republic of Korea
| | - Soo Jin Lim
- Department of Cardiology, Kim Hae Kangil Hospital, Gimhae, Republic of Korea
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21
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Nomura T, Niwa T, Ozawa S, Imai Y, Hashimoto J. Visibility of bronchial arteries using virtual and advanced virtual monoenergetic imaging. Acta Radiol 2020; 61:1618-1627. [PMID: 32429673 DOI: 10.1177/0284185120923992] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND The utility of virtual monoenergetic imaging (VMI) for fine arteries has not been well clarified. PURPOSE To assess bronchial artery visualization using VMI and noise-optimized advanced VMI (VMI+). MATERIAL AND METHODS Eighty-seven patients with esophageal cancer underwent computed tomography (CT) using a third-generation dual-source system before surgery. Tube voltages were set to 90 kVp and 150 kVp, respectively. Images were reconstructed using VMI and VMI+ with energy levels of 40-120 keV (in 10-keV increments); composite images equivalent to CT images at 105 kVp were also generated. The CT attenuation value and contrast-to-noise ratio (CNR) of bronchial arteries using VMI and VMI+ were compared with those obtained using composite imaging. Two radiologists subjectively analyzed bronchial artery visualization with reference to the composite image. RESULTS CT attenuation values for bronchial arteries using VMI at 40-60 keV and VMI+ at 40 keV and 50 keV were significantly higher than those obtained using composite imaging (P < 0.05). CNR using VMI at 40-60 keV was significantly higher than that obtained using composite imaging (P < 0.05), whereas no differences were noted for values obtained using composite imaging between VMI+ at 40 keV and 50 keV. In the subjective analysis, VMI at 40 keV and 50 keV yielded significantly better visibility of bronchial arteries than VMI+ (P < 0.05). CONCLUSION VMI and VMI+ at low voltages (40-50 keV) may be useful for bronchial artery visualization. VMI+ may be less effective for fine vessels as bronchial artery visualization.
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Affiliation(s)
- Takakiyo Nomura
- Department of Diagnostic Radiology, Tokai University School of Medicine, Isehara, Japan
| | - Tetsu Niwa
- Department of Diagnostic Radiology, Tokai University School of Medicine, Isehara, Japan
| | - Soji Ozawa
- Department of Gastroenterological Surgery, Tokai University School of Medicine, Isehara, Japan
| | - Yutaka Imai
- Department of Diagnostic Radiology, Tokai University School of Medicine, Isehara, Japan
| | - Jun Hashimoto
- Department of Diagnostic Radiology, Tokai University School of Medicine, Isehara, Japan
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22
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Xu JJ, Taudorf M, Ulriksen PS, Achiam MP, Resch TA, Nielsen MB, Lönn LB, Hansen KL. Gastrointestinal Applications of Iodine Quantification Using Dual-Energy CT: A Systematic Review. Diagnostics (Basel) 2020; 10:diagnostics10100814. [PMID: 33066281 PMCID: PMC7602017 DOI: 10.3390/diagnostics10100814] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 10/04/2020] [Accepted: 10/07/2020] [Indexed: 12/15/2022] Open
Abstract
Dual-energy computed tomography (DECT) can estimate tissue vascularity and perfusion via iodine quantification. The aim of this systematic review was to outline current and emerging clinical applications of iodine quantification within the gastrointestinal tract using DECT. The search was conducted with three databases: EMBASE, Pubmed and The Cochrane Library. This identified 449 studies after duplicate removal. From a total of 570 selected studies, 30 studies were enrolled for the systematic review. The studies were categorized into four main topics: gastric tumors (12 studies), colorectal tumors (8 studies), Crohn’s disease (4 studies) and miscellaneous applications (6 studies). Findings included a significant difference in iodine concentration (IC) measurements in perigastric fat between T1–3 vs. T4 stage gastric cancer, poorly and well differentiated gastric and colorectal cancer, responders vs. non-responders following chemo- or chemoradiotherapy treatment among cancer patients, and a positive correlation between IC and Crohn’s disease activity. In conclusion, iodine quantification with DECT may be used preoperatively in cancer imaging as well as for monitoring treatment response. Future studies are warranted to evaluate the capabilities and limitations of DECT in splanchnic flow.
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Affiliation(s)
- Jack Junchi Xu
- Department of Diagnostic Radiology, Copenhagen University Hospital, Rigshospitalet, 2100 Copenhagen, Denmark; (M.B.N.); (L.B.L.); (K.L.H.)
- Department of Surgical Gastroenterology, Copenhagen University Hospital, Rigshospitalet, 2100 Copenhagen, Denmark; (M.T.); (P.S.U.); (M.P.A.); (T.A.R.)
- Correspondence:
| | - Mikkel Taudorf
- Department of Surgical Gastroenterology, Copenhagen University Hospital, Rigshospitalet, 2100 Copenhagen, Denmark; (M.T.); (P.S.U.); (M.P.A.); (T.A.R.)
| | - Peter Sommer Ulriksen
- Department of Surgical Gastroenterology, Copenhagen University Hospital, Rigshospitalet, 2100 Copenhagen, Denmark; (M.T.); (P.S.U.); (M.P.A.); (T.A.R.)
| | - Michael Patrick Achiam
- Department of Surgical Gastroenterology, Copenhagen University Hospital, Rigshospitalet, 2100 Copenhagen, Denmark; (M.T.); (P.S.U.); (M.P.A.); (T.A.R.)
- Department of Vascular Surgery, Copenhagen University Hospital, Rigshospitalet, 2100 Copenhagen, Denmark
| | - Timothy Andrew Resch
- Department of Surgical Gastroenterology, Copenhagen University Hospital, Rigshospitalet, 2100 Copenhagen, Denmark; (M.T.); (P.S.U.); (M.P.A.); (T.A.R.)
- Department of Clinical Medicine, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Michael Bachmann Nielsen
- Department of Diagnostic Radiology, Copenhagen University Hospital, Rigshospitalet, 2100 Copenhagen, Denmark; (M.B.N.); (L.B.L.); (K.L.H.)
- Department of Surgical Gastroenterology, Copenhagen University Hospital, Rigshospitalet, 2100 Copenhagen, Denmark; (M.T.); (P.S.U.); (M.P.A.); (T.A.R.)
| | - Lars Birger Lönn
- Department of Diagnostic Radiology, Copenhagen University Hospital, Rigshospitalet, 2100 Copenhagen, Denmark; (M.B.N.); (L.B.L.); (K.L.H.)
- Department of Surgical Gastroenterology, Copenhagen University Hospital, Rigshospitalet, 2100 Copenhagen, Denmark; (M.T.); (P.S.U.); (M.P.A.); (T.A.R.)
| | - Kristoffer Lindskov Hansen
- Department of Diagnostic Radiology, Copenhagen University Hospital, Rigshospitalet, 2100 Copenhagen, Denmark; (M.B.N.); (L.B.L.); (K.L.H.)
- Department of Surgical Gastroenterology, Copenhagen University Hospital, Rigshospitalet, 2100 Copenhagen, Denmark; (M.T.); (P.S.U.); (M.P.A.); (T.A.R.)
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Lee S, Choi YH, Cho YJ, Lee SB, Cheon JE, Kim WS, Ahn CK, Kim JH. Noise reduction approach in pediatric abdominal CT combining deep learning and dual-energy technique. Eur Radiol 2020; 31:2218-2226. [PMID: 33030573 DOI: 10.1007/s00330-020-07349-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 08/15/2020] [Accepted: 09/24/2020] [Indexed: 12/12/2022]
Abstract
OBJECTIVES To evaluate the image quality of low iodine concentration, dual-energy CT (DECT) combined with a deep learning-based noise reduction technique for pediatric abdominal CT, compared with standard iodine concentration single-energy polychromatic CT (SECT). METHODS From December 2016 to May 2017, DECT with 300 mg•I/mL contrast medium was performed in 29 pediatric patients (17 boys, 12 girls; age, 2-19 years). The DECT images were reconstructed using a noise-optimized virtual monoenergetic reconstruction image (VMI) with and without a deep learning method. SECT images with 350 mg•I/mL contrast medium, performed within the last 3 months before the DECT, served as reference images. The quantitative and qualitative parameters were compared using paired t tests and Wilcoxon signed-rank tests, and the differences in radiation dose and total iodine administration were assessed. RESULTS The linearly blended DECT showed lower attenuation and higher noise than SECT. The 60-keV VMI showed an increase in attenuation and higher noise than SECT. The combined 60-keV VMI plus deep learning images showed low noise, no difference in contrast-to-noise ratios, and overall image quality or diagnostic image quality, but showed a higher signal-to-noise ratio in the liver and lower enhancement of lesions than SECT. The overall image and diagnostic quality of lesions were maintained on the combined noise reduction approach. The CT dose index volume and total iodine administration in DECT were respectively 19.6% and 14.3% lower than those in SECT. CONCLUSION Low iodine concentration DECT, combined with deep learning in pediatric abdominal CT, can maintain image quality while reducing the radiation dose and iodine load, compared with standard SECT. KEY POINTS • An image noise reduction approach combining deep learning and noise-optimized virtual monoenergetic image reconstruction can maintain image quality while reducing radiation dose and iodine load. • The 60-keV virtual monoenergetic image reconstruction plus deep learning images showed low noise, no difference in contrast-to-noise ratio, and overall image quality, but showed a higher signal-to-noise ratio in the liver and a lower enhancement of lesion than single-energy polychromatic CT. • This combination could offer a 19.6% reduction in radiation dose and a 14.3% reduction in iodine load, in comparison with a control group that underwent single-energy polychromatic CT with the standard protocol.
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Affiliation(s)
- Seunghyun Lee
- Department of Radiology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Young Hun Choi
- Department of Radiology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea. .,Department of Radiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.
| | - Yeon Jin Cho
- Department of Radiology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Seul Bi Lee
- Department of Radiology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Jung-Eun Cheon
- Department of Radiology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.,Department of Radiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.,Institute of Radiation Medicine, Seoul National University Medical Research Center, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Woo Sun Kim
- Department of Radiology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.,Department of Radiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.,Institute of Radiation Medicine, Seoul National University Medical Research Center, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Chul Kyun Ahn
- Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Jong Hyo Kim
- Department of Radiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.,Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.,Advanced Institutes of Convergence Technology, Seoul National University, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
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24
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D'Angelo T, Lenga L, Arendt CT, Bucher AM, Peterke JL, Caruso D, Mazziotti S, Ascenti G, Blandino A, Othman AE, Martin SS, Albrecht MH, Bodelle B, Vogl TJ, Wichmann JL. Carotid and cerebrovascular dual-energy computed tomography angiography: Optimization of window settings for virtual monoenergetic imaging reconstruction. Eur J Radiol 2020; 130:109166. [PMID: 32693314 DOI: 10.1016/j.ejrad.2020.109166] [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] [Received: 09/29/2019] [Revised: 04/25/2020] [Accepted: 07/05/2020] [Indexed: 02/08/2023]
Abstract
PURPOSE Dedicated post-processing of dual-energy computed tomography angiography (DE-CTA) datasets has been shown to allow for increased vascular contrast. The goal of our study was to define optimal window settings for displaying virtual monoenergetic images (VMI) reconstructed from dual-energy carotid and cerebrovascular DE-CTA. METHODS Fifty-seven patients who underwent clinically-indicated carotid and cerebrovascular third-generation dual-source DE-CTA were retrospectively evaluated. Standard linearly-blended (M_0.6), 70-keV traditional VMI (M70), and 40-keV noise-optimized VMI (M40+) reconstructions were analyzed. For M70 and M40+ datasets, the subjectively best window setting (width and level, B-W/L) was independently determined by two observers and subsequently related with aortic arch attenuation to calculate optimized values (O-W/L) using linear regression. Subjective evaluation of image quality (IQ) between W/L settings were assessed by two additional readers. Repeated measures analysis of variance were performed to compare W/L settings and IQ indices between M_0.6, M70, and M40 + . RESULTS B-W/L and O-W/L for M70 were 580/210 and 560/200, and for M40+ were 1630/570 and 1560/550, respectively, higher than standard DE-CTA W/L settings (450/100). Highest subjective scores were observed for M40+ regarding overall IQ (all p < 0.001). CONCLUSION Application of O-W/L settings is mandatory to optimize subjective IQ of VMI reconstructions of DE-CTA.
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Affiliation(s)
- Tommaso D'Angelo
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany; Department of Biomedical Sciences and Morphological and Functional Imaging, "G. Martino" University Hospital Messina, Via Consolare Valeria 1, 98100, Messina, Italy
| | - Lukas Lenga
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Christophe T Arendt
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Andreas M Bucher
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Julia L Peterke
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Damiano Caruso
- Department of Radiological Sciences, Oncological and Pathological Sciences, "La Sapienza'' University Hospital, Latina, Italy
| | - Silvio Mazziotti
- Department of Biomedical Sciences and Morphological and Functional Imaging, "G. Martino" University Hospital Messina, Via Consolare Valeria 1, 98100, Messina, Italy
| | - Giorgio Ascenti
- Department of Biomedical Sciences and Morphological and Functional Imaging, "G. Martino" University Hospital Messina, Via Consolare Valeria 1, 98100, Messina, Italy
| | - Alfredo Blandino
- Department of Biomedical Sciences and Morphological and Functional Imaging, "G. Martino" University Hospital Messina, Via Consolare Valeria 1, 98100, Messina, Italy
| | - Ahmed E Othman
- Department for Diagnostic and Interventional Radiology, Eberhard Karls University Tuebingen, University Hospital Tübingen, Tübingen, Germany
| | - Simon S Martin
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Moritz H Albrecht
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Boris Bodelle
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Thomas J Vogl
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Julian L Wichmann
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany.
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Lysdahlgaard S, Hess S, Gerke O, Weber Kusk M. A systematic literature review and meta-analysis of spectral CT compared to scintigraphy in the diagnosis of acute and chronic pulmonary embolisms. Eur Radiol 2020; 30:3624-3633. [PMID: 32112117 DOI: 10.1007/s00330-020-06735-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 12/20/2019] [Accepted: 02/07/2020] [Indexed: 01/26/2023]
Abstract
PURPOSE To examine the diagnostic accuracy of spectral CT pulmonary angiography (S-CTPA) using ventilation-perfusions lung scintigraphy (V/Q-scan) as a reference standard in the diagnosis of acute or chronic pulmonary embolism (APE/CPE) and chronic thromboembolic pulmonary hypertension (CTEPH). METHODS PubMed, Embase, Scopus, and Web of Science were searched for the period from 1 Jan 2006 to 7 Feb 2019; eligible studies had > 10 patients over 18 years old, a diagnostic outcome of PE or CTEPH, and used V/Q scan as a reference standard. Bias and applicability were assessed using QUADAS-2 tools. Sensitivities, specificities, and predictive values were noted or calculated from available information. Meta-analysis employed a fixed-effects model of Mantel and Haenszel. Heterogeneity was assessed with I-squared statistics. RESULTS Four hundred ninety-three unique records were identified. Following screening by title, 53 studies were included in the abstract and full-text assessment. A total of six articles were included; four were suitable for a meta-analysis. Pooled sensitivity was 94.2% (95% CI, 88.3-100%), pooled specificity was 88.5% (95% CI, 81.3-95.6%), and positive and negative predictive values were 87.8% (95% CI, 80.3-95.4%) and 94.5% (95% CI, 89.3-99.7%), respectively. CONCLUSION Data on S-CTPA for PE/CTEPH remains promising, but limited; only small studies with methodological issues are available. Evidence is best for CPE/CTEPH whereas no firm conclusions are possible for APE. There is a need for larger, prospective studies with a robust composite reference standard including state-of-the-art CTPA and V/Q-scans. KEY POINTS • S-CTPA has high sensitivity and specificity for perfusion defects in patients with PE or CPETH. • Methodological issues and diversity of reference standards were found in the small number of included studies. • There is a need for larger prospective studies with more robust composite reference standards.
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Affiliation(s)
- Simon Lysdahlgaard
- Department of Radiology and Nuclear Medicine, University Hospital of Southwest Jutland, Esbjerg, Denmark.
| | - Søren Hess
- Department of Radiology and Nuclear Medicine, University Hospital of Southwest Jutland, Esbjerg, Denmark
- Department of Regional Health Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
| | - Oke Gerke
- Department of Nuclear Medicine, Odense University Hospital, Odense, Denmark
- Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
| | - Martin Weber Kusk
- Department of Radiology and Nuclear Medicine, University Hospital of Southwest Jutland, Esbjerg, Denmark
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Kawahara D, Ozawa S, Yokomachi K, Fujioka C, Kimura T, Awai K, Nagata Y. Synthesized effective atomic numbers for commercially available dual-energy CT. Rep Pract Oncol Radiother 2020; 25:692-697. [PMID: 32684854 DOI: 10.1016/j.rpor.2020.02.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 02/19/2020] [Indexed: 01/24/2023] Open
Abstract
Purpose The objective of this study was to assess synthesized effective atomic number (Zeff) values with a new developed tissue characteristic phantom and contrast material of varying iodine concentrations using single-source fast kilovoltage switching dual-energy CT (DECT) scanner. Methods A newly developed multi energy tissue characterisation CT phantom and an acrylic phantom with various iodine concentrations of were scanned using single-source fast kilovoltage switching DECT (GE-DECT) scanner. The difference between the measured and theoretical values of Zeff were evaluated. Additionally, the difference and coefficient of variation (CV) values of the theoretical and measured values were compared with values obtained with the Canon-DECT scanner that was analysed in our previous study. Results The average Zeff difference in the Multi-energy phantom was within 4.5%. The average difference of the theoretical and measured Zeff values for the acrylic phantom with variation of iodine concentration was within 3.3%. Compared to the results for the single-source Canon-DECT scanner used in our previous study, the average difference and CV of the theoretical and measured Zeff values obtained with the GE-DECT scanner were markedly smaller. Conclusions The accuracy of the synthesized Zeff values with GE-DECT had a good agreement with the theoretical Zeff values for the Multi-Energy phantom. The GE-DECT could reduce the noise and the accuracy of the Zeff values than that with Canon-DECT for the varying iodine concentrations of contrast medium. Advances in knowledge The accuracy and precision of the Zeff values of the contrast medium with the GE-DECT could be sufficient with human equivalent materials.
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Affiliation(s)
- Daisuke Kawahara
- Department of Radiation Oncology, Institute of Biomedical & Health Sciences, Hiroshima University, Japan
| | - Shuichi Ozawa
- Department of Radiation Oncology, Institute of Biomedical & Health Sciences, Hiroshima University, Japan.,Hiroshima High-Precision Radiotherapy Cancer Center, Japan
| | - Kazushi Yokomachi
- Radiation Therapy Section, Division of Clinical Support, Hiroshima University Hospital, Japan
| | - Chikako Fujioka
- Radiation Therapy Section, Division of Clinical Support, Hiroshima University Hospital, Japan
| | - Tomoki Kimura
- Department of Radiation Oncology, Institute of Biomedical & Health Sciences, Hiroshima University, Japan
| | - Kazuo Awai
- Department of Radiation Oncology, Graduate School of Medicine, Hiroshima University, Japan
| | - Yasushi Nagata
- Department of Radiation Oncology, Institute of Biomedical & Health Sciences, Hiroshima University, Japan.,Hiroshima High-Precision Radiotherapy Cancer Center, Japan
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28
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Kraus MS, Selo N, Kiefer LS, Esser M, Albtoush OM, Weiss J, Wichmann JL, Bamberg F, Othman AE. Advanced Virtual Monoenergetic Imaging: Improvement of Visualization and Differentiation of Intramuscular Lesions in Portal-Venous-phase Contrast-enhanced Dual-energy CT. Acad Radiol 2019; 26:1457-1465. [PMID: 30879946 DOI: 10.1016/j.acra.2019.02.014] [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] [Received: 11/27/2018] [Revised: 02/06/2019] [Accepted: 02/08/2019] [Indexed: 12/20/2022]
Abstract
PURPOSE To evaluate the effect of advanced monoenergetic imaging (MEI+) postprocessing algorithm on the visualization of various intramuscular lesions on portal-venous-phase contrast-enhanced dual-energy computed tomography (DECT). MATERIAL AND METHODS Thirty-nine patients (64.3 ± 11.1 years; 26 males) with various intramuscular lesions ranging from malignancy, bleeding, inflammation, edematous changes, and benign neoplasms were included and underwent DECT (100/Sn150kV). Postprocessing with MEI+ technique was used to reconstruct images at four different keV levels (40, 60, 80, 100) and compared to the standard portal-venous-phase CT (CTpv) images. Image quality was assessed qualitatively (conspicuity, delineation, sharpness, noise, and confidence) by two independent readers using 5-point Likert scales, 5 = excellent; as well as quantitatively by calculating signal-to-noise ratios (SNR), contrast-to-noise ratios (CNR), and area under the receiver operating characteristic (ROC) curve (AUC) for lesion characterization. RESULTS Highest lesion enhancement and diagnostic confidence were observed in MEI+ 40 keV, with significant differences to CTpv (p < 0.001), as well as for malignant lesions (highest conspicuity, noise, and sharpness in MEI+ 40 keV; p < 0.001). CNR calculations revealed highest values for MEI+ 40 keV followed by 60 keV with significant differences to CTpv, and increasing energy levels. ROC analysis showed highest diagnostic accuracy for 40-keV MEI+ datasets regarding the detection of malignant/benign lesions with AUC values of 98.9% (95%-confidence interval: 96.5, 100) and a standard error of 1.2, further AUC values decreased to 83.6% for MEI+100. CONCLUSION MEI+ at low keV levels can significantly improve lesion detection of benign versus malignant intramuscular entities in patients undergoing portal-venous-phase DECT scans due to increased CNR.
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Albrecht MH, Vogl TJ, Martin SS, Nance JW, Duguay TM, Wichmann JL, De Cecco CN, Varga-Szemes A, van Assen M, Tesche C, Schoepf UJ. Review of Clinical Applications for Virtual Monoenergetic Dual-Energy CT. Radiology 2019; 293:260-271. [DOI: 10.1148/radiol.2019182297] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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Kim TM, Choi YH, Cheon JE, Kim WS, Kim IO, Park JE, Shin SM, Pak SY, Krauss B. Optimal Kiloelectron Volt for Noise-Optimized Virtual Monoenergetic Images of Dual-Energy Pediatric Abdominopelvic Computed Tomography: Preliminary Results. Korean J Radiol 2019; 20:283-294. [PMID: 30672168 PMCID: PMC6342763 DOI: 10.3348/kjr.2017.0507] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 04/30/2018] [Indexed: 12/11/2022] Open
Abstract
Objective To compare quantitative and qualitative image quality parameters in pediatric abdominopelvic dual-energy CT (DECT) using noise-optimized virtual monoenergetic image (VMI) and conventional VMI at different kiloelectron volt (keV) levels. Materials and Methods Thirty-six consecutive abdominopelvic DECT scans were retrospectively included. Noise-optimized VMI and conventional VMI were reconstructed at seven energy levels, from 40 keV to 100 keV at 10 keV intervals. The contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) of the liver, pancreas, and aorta were objectively measured and compared. Image quality was evaluated subjectively regarding image noise, image blurring of solid organ, bowel image quality and severity of beam-hardening artifacts. Optimal monoenergetic levels in keV for both algorithms were determined based on overall image quality score. Results The maximal CNR and SNR values for all investigated organs were observed at 40 keV in noise-optimized VMI (CNR and SNR of liver, pancreas, aorta in order [CNR; 20.93, 17.34, 46.75: SNR; 37.39, 33.80, 63.21]), at 60–70 keV and at 70 keV in conventional VMI (CNR; 8.12, 5.67, 15.97: SNR; 19.57, 16.66, 26.65). In qualitative image analysis, noise-optimized VMI and conventional VMI showed the best overall image quality scores at 60 keV and at 70 keV, respectively. Noise-optimized VMI at 60 keV showed superior CNRs, SNRs, and overall image quality scores compared to conventional VMI at 70 keV (p < 0.001). Conclusion Optimal energy levels for noise-optimized VMI and conventional VMI were 60 keV and at 70 keV, respectively. Noise-optimized VMI shows superior CNRs, SNRs and subjective image quality over conventional VMI, at the optimal energy level.
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Affiliation(s)
- Taek Min Kim
- Department of Radiology, Seoul National University Hospital, Seoul, Korea.,Department of Radiology, Seoul National University College of Medicine, Seoul, Korea
| | - Young Hun Choi
- Department of Radiology, Seoul National University Hospital, Seoul, Korea.,Department of Radiology, Seoul National University College of Medicine, Seoul, Korea.
| | - Jung Eun Cheon
- Department of Radiology, Seoul National University Hospital, Seoul, Korea.,Department of Radiology, Seoul National University College of Medicine, Seoul, Korea.,Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea
| | - Woo Sun Kim
- Department of Radiology, Seoul National University Hospital, Seoul, Korea.,Department of Radiology, Seoul National University College of Medicine, Seoul, Korea.,Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea
| | - In One Kim
- Department of Radiology, Seoul National University Hospital, Seoul, Korea.,Department of Radiology, Seoul National University College of Medicine, Seoul, Korea.,Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea
| | - Ji Eun Park
- Department of Radiology, Kyung Hee University Hospital, Seoul, Korea
| | - Su Mi Shin
- Department of Radiology, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul, Korea
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Kawahara D, Ozawa S, Yokomachi K, Higaki T, Fujioka C, Mori M, Nagata Y. Improving automatic contrast agent extraction system using monochromatic CT number. AUSTRALASIAN PHYSICAL & ENGINEERING SCIENCES IN MEDICINE 2019; 42:819-826. [DOI: 10.1007/s13246-019-00762-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 05/08/2019] [Indexed: 11/30/2022]
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Sekiguchi T, Ozawa Y, Hara M, Nakagawa M, Goto T, Shibamoto Y. Visibility of the hilar lymph nodes using advanced virtual monoenergetic low-keV images for preoperative evaluation of lung cancer. Br J Radiol 2019; 92:20180734. [PMID: 31430185 DOI: 10.1259/bjr.20180734] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
OBJECTIVE The purpose of our study was to evaluate the visibility of the hilar lymph nodes (LNs) using advanced virtual monoenergetic low-keV images compared with early-phase contrast-enhanced CT. METHODS Dual energy contrast-enhanced CT was performed for pre-operative evaluation of lung cancer at 20 and 60 s after administration of contrast media in 50 patients (32 males and 18 females; mean age, 69 years). Five kinds of images (A: 20 s/120 kV; B: 60 s/40 keV; C: 60 s/50 keV; D: 60 s/120 kV; E: 60 s/100 kV) were reconstructed. We measured the CT number of the bilateral main pulmonary arteries (PAs), pulmonary veins (PVs) and hilar LNs, and evaluated the differences in CT number (Hounsfield units, HUs) between the PA/PV and LNs (PA-LN and PV-LN contrast). Artifacts from the superior vena cava (SVC) were also evaluated. RESULTS The mean PA-LN contrast (HU) was 415 in image group A, 299 in B, 180 in C, 80 in D, and 100 in E. The mean PV-LN contrasts in each group were 306, 287, 177, 78, and 99, respectively. Image group B showed the second highest PA-LN contrast following image group A. There was no significant difference in the PV-LN contrast between image groups A and B. The PA-LN and PV-LN contrasts of image groups B and C were significantly higher than those of E. SVC artifacts were lower in the delayed-phase images (Group B-E) than in Group A. CONCLUSION To evaluate the hilar LNs with a single image series, advanced virtual monoenergetic 40-keV imaging at the delayed 60-s phase seems to be the most valuable. ADVANCES IN KNOWLEDGE Advanced virtual monoenergetic image is useful for evaluation of both hilar LNs and tumors in the delayed phase without artifact derived from the streak artifact from dense contrast media in the SVC.
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Affiliation(s)
- Tomoya Sekiguchi
- Department of Radiology, Nagoya City University Graduate School of Medical Sciences
| | - Yoshiyuki Ozawa
- Department of Radiology, Nagoya City University Graduate School of Medical Sciences
| | - Masaki Hara
- Department of Radiology, Nagoya City West Medical Center
| | - Motoo Nakagawa
- Department of Radiology, Nagoya City University Graduate School of Medical Sciences
| | - Taeko Goto
- Department of Radiology, Nagoya City University Graduate School of Medical Sciences
| | - Yuta Shibamoto
- Department of Radiology, Nagoya City University Graduate School of Medical Sciences
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Iuga AI, Doerner J, Siedek F, Haneder S, Byrtus J, Luetkens JA, Maintz D, Hickethier T. Computed tomography pulmonary angiograms using a novel dual-layer spectral detector: Adjusted window settings are essential for diagnostic image quality. Medicine (Baltimore) 2019; 98:e16606. [PMID: 31415352 PMCID: PMC6831234 DOI: 10.1097/md.0000000000016606] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
OBJECTIVE The aim of this study was to determine optimal window settings for conventional polyenergetic and virtual monoenergetic images derived from computed tomography pulmonary angiogram (CTPA) examinations of a novel dual-layer spectral detector computed tomography system (DLCT). METHODS Monoenergetic (40 keV) and polyenergetic images of 50 CTPA examinations were calculated and the best individual window width and level (W/L) values were manually assessed. Optimized values were obtained afterwards based on regression analysis. Diameters of standardized pulmonary artery segments and subjective image quality parameters were evaluated and compared. RESULTS Attenuation and contrast-to-noise values were higher in monoenergetic than in polyenergetic images (P≤.001). Averaged best individual W/L for polyenergetic and monoenergetic were 1020/170 and 2070/480 HU, respectively.All adjusted W/L-settings varied significantly compared to standard settings (700/100 HU) and obtained higher subjective image quality scores. A systematic overestimation of artery diameters for standard window settings in monoenergetic images was observed. CONCLUSIONS Appropriate W/L-settings are required to assess polyenergetic and monoenergetic CTPA images of a novel DLCT. W/L-settings of 1020/170 HU and 2070/480 HU were found to be the best averaged values for polyenergetic and monoenergetic CTPA images, respectively.
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Affiliation(s)
- Andra-Iza Iuga
- Institute of Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne
| | - Jonas Doerner
- Institute of Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne
| | - Florian Siedek
- Institute of Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne
| | - Stefan Haneder
- Institute of Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne
| | - Jonathan Byrtus
- Institute of Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne
| | - Julian A. Luetkens
- Institute of Diagnostic and Interventional Radiology, University of Bonn, Bonn, Germany
| | - David Maintz
- Institute of Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne
| | - Tilman Hickethier
- Institute of Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne
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Topçuoğlu OM, Sarıkaya B. Fast kilovoltage-switching dual-energy CT offering lower x-ray dose than single-energy CT for the chest: a quantitative and qualitative comparison study of the two methods of acquisition. Diagn Interv Radiol 2019; 25:204-209. [PMID: 31085505 PMCID: PMC6521909 DOI: 10.5152/dir.2019.18412] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 10/07/2018] [Accepted: 11/13/2018] [Indexed: 11/22/2022]
Abstract
PURPOSE We aimed to compare the size-specific dose estimates (SSDE), computed tomography (CT) dose indices and image quality parameters of the chest CTs obtained with fast kilovoltage-switching (FKS) dual-energy (DE) CT versus those with single-energy (SE) CT. METHODS Patients who had chest SECT within the last 6 months were prospectively scanned with chest FKS-DECT. Quantitative comparison was made by calculating the mean SSDE, CTDIvol, contrast, noise, contrast-to-noise ratio (CNR), and signal-to-noise ratio (SNR) for both acquisitions. Two radiologists evaluated the chest SECT and DECT images qualitatively blinded to the technique used. The paired Student's t test was utilized for comparing the quantitative and qualitative data. Inter- and intraobserver agreement were also assessed. RESULTS A total of 42 patients were included. The mean SSDE, CTDIvol, contrast, noise, CNR, and SNR for SECT versus DECT were 12.7±2.2 mGy vs. 9.3±1.2 mGy (P = 0.001), 10.9±2.4 mGy vs. 8±1.2 mGy (P < 0.001), 211.9±44.7 vs. 216.3±59 (P = 0.350), 12.9±2.4 vs. 13.9±3.7 (P = 0.086), 13.5±5.2 vs. 13.3±8.4 (P = 0.548) and 12±3.5 vs. 11.5±3.4 (P = 0.774), respectively. Interobserver reproducibility was high for contrast, noise, CNR, and SNR (ICC = 0.89, 0.85, 0.93, and 0.82, respectively; all P < 0.05). Intraobserver reproducibility was high for contrast, noise, CNR, and SNR (ICC = 0.80, 0.77, 0.85, and 0.88, respectively; all P < 0.05). CONCLUSION The mean SSDE of the chest CTs obtained with FKS-DECT were 26.8% lower than those with SECT with significant difference for the objective assessment and there was no significant difference for the subjective assessment of the image qualities, in this series.
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Affiliation(s)
- Osman Melih Topçuoğlu
- From the Department of Radiology (O.M.T. ) Yeditepe University School of Medicine, İstanbul, Turkey
| | - Başar Sarıkaya
- From the Department of Radiology (O.M.T. ) Yeditepe University School of Medicine, İstanbul, Turkey
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D'Angelo T, Cicero G, Mazziotti S, Ascenti G, Albrecht MH, Martin SS, Othman AE, Vogl TJ, Wichmann JL. Dual energy computed tomography virtual monoenergetic imaging: technique and clinical applications. Br J Radiol 2019; 92:20180546. [PMID: 30919651 DOI: 10.1259/bjr.20180546] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Dual energy CT (DECT) has evolved into a commonly applied imaging technique in clinical routine due to its unique post-processing opportunities for improved evaluation of all body areas. Reconstruction of virtual monoenergetic imaging (VMI) series has shown beneficial effects for both non-contrast and contrast-enhanced DECT due to the flexibility to calculate low-keV VMI reconstructions to increase contrast and iodine attenuation, or to compute high-keV VMI reconstructions to reduce beam-hardening artefacts. The goal of this review article is to explain the technical background of VMI and noise-optimized VMI+ algorithms and to give an overview of useful clinical applications of the VMI technique in DECT of various body regions.
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Affiliation(s)
- Tommaso D'Angelo
- 1 Department of Biomedical Sciences and Morphological and Functional Imaging, Policlinico G. Martino - University Hospital Messina , Messina , Italy.,2 Department of Diagnostic and Interventional Radiology, Division of Experimental Imaging, University Hospital Frankfurt , Frankfurt , Germany
| | - Giuseppe Cicero
- 1 Department of Biomedical Sciences and Morphological and Functional Imaging, Policlinico G. Martino - University Hospital Messina , Messina , Italy
| | - Silvio Mazziotti
- 1 Department of Biomedical Sciences and Morphological and Functional Imaging, Policlinico G. Martino - University Hospital Messina , Messina , Italy
| | - Giorgio Ascenti
- 1 Department of Biomedical Sciences and Morphological and Functional Imaging, Policlinico G. Martino - University Hospital Messina , Messina , Italy
| | - Moritz H Albrecht
- 2 Department of Diagnostic and Interventional Radiology, Division of Experimental Imaging, University Hospital Frankfurt , Frankfurt , Germany
| | - Simon S Martin
- 2 Department of Diagnostic and Interventional Radiology, Division of Experimental Imaging, University Hospital Frankfurt , Frankfurt , Germany
| | - Ahmed E Othman
- 3 Department of Diagnostic and Interventional Radiology, Eberhard Karls University Tübingen , Tübingen , Germany
| | - Thomas J Vogl
- 2 Department of Diagnostic and Interventional Radiology, Division of Experimental Imaging, University Hospital Frankfurt , Frankfurt , Germany
| | - Julian L Wichmann
- 2 Department of Diagnostic and Interventional Radiology, Division of Experimental Imaging, University Hospital Frankfurt , Frankfurt , Germany
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Comparison of Radiation Dose and Image Quality of Contrast-Enhanced Dual-Source CT of the Chest: Single-Versus Dual-Energy and Second-Versus Third-Generation Technology. AJR Am J Roentgenol 2019; 212:741-747. [PMID: 30699006 DOI: 10.2214/ajr.18.20065] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Gottumukkala RV, Kalra MK, Tabari A, Otrakji A, Gee MS. Advanced CT Techniques for Decreasing Radiation Dose, Reducing Sedation Requirements, and Optimizing Image Quality in Children. Radiographics 2019; 39:709-726. [PMID: 30924753 DOI: 10.1148/rg.2019180082] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
CT is an invaluable diagnostic tool for pediatric patients; however, concerns have arisen about the potential risks of ionizing radiation associated with diagnostic imaging in young patients, particularly for pediatric populations that may require serial CT examinations. Recent attention has also been focused on the immediate and long-term risks of administration of anesthetic medications to infants and young children who require sedation to undergo imaging examinations. These concerns can be mitigated with use of advanced CT techniques that can decrease scan time and radiation dose while preserving image quality. In this article, current state-of-the-art CT acquisition techniques are reviewed as part of a comprehensive strategy to reduce radiation dose, decrease sedation needs, and optimize image quality in infants and young children. Three imaging strategies are discussed, including (a) dual-energy CT (DECT), (b) imaging with a low tube potential, and (c) rapid scanning. Consolidating multiphase imaging protocols into a single phase with virtual nonenhanced imaging on DECT scanners, as well as use of low tube voltage, can reduce the radiation dose while increasing the conspicuity of contrast material-enhanced structures with a reduced volume of iodinated contrast material and a reduced rate of injection. Rapid scanning techniques with either ultrahigh pitch at dual-source CT or with wide-area detector single-source CT facilitate scanning without the need for sedation in many children. ©RSNA, 2019 See discussion on this article by Szczykutowicz .
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Affiliation(s)
- Ravi V Gottumukkala
- From the Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Boston, MA 02114
| | - Mannudeep K Kalra
- From the Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Boston, MA 02114
| | - Azadeh Tabari
- From the Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Boston, MA 02114
| | - Alexi Otrakji
- From the Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Boston, MA 02114
| | - Michael S Gee
- From the Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Boston, MA 02114
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Murphy A, Cheng J, Pratap J, Redman R, Coucher J. Dual-Energy Computed Tomography Pulmonary Angiography: Comparison of Vessel Enhancement between Linear Blended and Virtual Monoenergetic Reconstruction Techniques. J Med Imaging Radiat Sci 2019; 50:62-67. [PMID: 30777250 DOI: 10.1016/j.jmir.2018.10.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 10/18/2018] [Accepted: 10/18/2018] [Indexed: 12/29/2022]
Abstract
INTRODUCTION Optimal opacification of the pulmonary vasculature is a fundamental factor of a diagnostic quality computed tomography pulmonary angiogram (CTPA). This retrospective study examined the feasibility of utilising a noise-optimised monoenergetic reconstruction of the dual-energy computed tomography pulmonary angiogram (DE-CTPA) as an additional protocol to increase vessel opacification. METHOD The study involved a retrospective analysis of 129 patients, 69 males (average age 58 years), 60 females (average age 56 years) who underwent a DE-CTPA at a tertiary referral hospital. Linear blended 120 kilovoltage (kV) images (LB120) dual-energy (DE) data sets (50% 100 kV and 50% 140 kV) were compared to noise-optimised virtual monoenergetic image reconstruction (VMI+) at 40 kiloelectron volts (VMI+40). The attenuation of the pulmonary trunk measured in Hounsfield units (HU) between the equivalent axial slices of the LB120 data set and the VMI+40 data set underwent statistical analysis via a Wilcoxon paired-sample test. RESULTS VMI+40 (1161.500 HU) yielded a statistically significant increase in median attenuation within the pulmonary trunk compared to the LB120 (304.400 HU), with a median difference between monoenergetic reconstruction and standard dual energy of data sets of 827.5 HU (P < .001). CONCLUSIONS VMI+40 of the DE-CTPA scan demonstrates a statistically significant increase in vessel attenuation in all cases and may have utility in reducing the rates of indeterminate or repeated studies.
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Affiliation(s)
- Andrew Murphy
- Department of Medical Imaging, British Columbia Children's Hospital, Vancouver, Canada; Department of Medical Imaging, St Paul's Hospital, Vancouver, Canada; Faculty of Health Sciences, The University of Sydney, Discipline of Medical Radiation Sciences, Cumberland Campus, Lidcombe, Australia.
| | - Jeffrey Cheng
- Department of Medical Imaging, Princess Alexandra Hospital, Brisbane, Australia
| | - Jit Pratap
- Department of Medical Imaging, Princess Alexandra Hospital, Brisbane, Australia
| | - Renae Redman
- Department of Medical Imaging, Princess Alexandra Hospital, Brisbane, Australia
| | - John Coucher
- Department of Medical Imaging, Princess Alexandra Hospital, Brisbane, Australia
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Wang T, Ghavidel BB, Beitler JJ, Tang X, Lei Y, Curran WJ, Liu T, Yang X. Optimal virtual monoenergetic image in "TwinBeam" dual-energy CT for organs-at-risk delineation based on contrast-noise-ratio in head-and-neck radiotherapy. J Appl Clin Med Phys 2019; 20:121-128. [PMID: 30693665 PMCID: PMC6370994 DOI: 10.1002/acm2.12539] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 12/21/2018] [Accepted: 01/02/2019] [Indexed: 01/04/2023] Open
Abstract
PURPOSE Dual-energy computed tomography (DECT) using TwinBeam CT (TBCT) is a new option for radiation oncology simulators. TBCT scanning provides virtual monoenergetic images which are attractive in treatment planning since lower energies offer better contrast for soft tissues, and higher energies reduce noise. A protocol is needed to achieve optimal performance of this feature. In this study, we investigated the TBCT scan schema with the head-and-neck radiotherapy workflow at our clinic and selected the optimal energy with best contrast-noise-ratio (CNR) in organs-at-risks (OARs) delineation for head-and-neck treatment planning. METHODS AND MATERIALS We synthesized monochromatic images from 40 keV to 190 keV at 5 keV increments from data acquired by TBCT. We collected the Hounsfield unit (HU) numbers of OARs (brainstem, mandible, spinal cord, and parotid glands), the HU numbers of marginal regions outside OARs, and the noise levels for each monochromatic image. We then calculated the CNR for the different OARs at each energy level to generate a serial of spectral curves for each OAR. Based on these spectral curves of CNR, the mono-energy corresponding to the max CNR was identified for each OAR of each patient. RESULTS Computed tomography scans of ten patients by TBCT were used to test the optimal monoenergetic image for the CNR of OAR. Based on the maximized CNR, the optimal energy values were 78.5 ± 5.3 keV for the brainstem, 78.0 ± 4.2 keV for the mandible, 78.5 ± 5.7 keV for the parotid glands, and 78.5 ± 5.3 keV for the spinal cord. Overall, the optimal energy for the maximum CNR of these OARs in head-and-neck cancer patients was 80 keV. CONCLUSION We have proposed a clinically feasible protocol that selects the optimal energy level of the virtual monoenergetic image in TBCT for OAR delineation based on the CNR in head-and-neck OAR. This protocol can be applied in TBCT simulation.
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Affiliation(s)
- Tonghe Wang
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, 30322, USA
| | - Beth Bradshaw Ghavidel
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, 30322, USA
| | - Jonathan J Beitler
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, 30322, USA
| | - Xiangyang Tang
- Department of Radiology and Imaging Sciences and Winship Cancer Institute, Emory University, Atlanta, GA, 30322, USA
| | - Yang Lei
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, 30322, USA
| | - Walter J Curran
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, 30322, USA
| | - Tian Liu
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, 30322, USA
| | - Xiaofeng Yang
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA, 30322, USA
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Spectral Detector Computed Tomography Pulmonary Angiography: Improved Diagnostic Assessment and Automated Estimation of Window Settings Angiography of Pulmonary Arteries From Novel Spectral Detector Computed Tomography Provides Improved Image Quality if Settings are Adjusted. J Comput Assist Tomogr 2018; 42:850-857. [PMID: 29659429 DOI: 10.1097/rct.0000000000000743] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
OBJECTIVE This study aimed to evaluate image quality (IQ) of virtual monoenergetic images (VMIs) from novel spectral detector computed tomography angiography of the pulmonary arteries and to identify appropriate window settings for each kiloelectron volt level. MATERIALS Forty consecutive patients were included in this institutional review board-approved, Health Insurance Portability and Accountability Act-compliant study.Signal- and contrast-to-noise ratios were calculated within the pulmonary trunk, and pulmonary/lobar/segmental arteries were calculated. The IQ and diagnostic certainty were rated by 2 radiologists on 5-point scales. In addition, they recorded appropriate window settings (center/width) that were linearly modeled against attenuation within the pulmonary trunk to generate generable results. RESULTS Signal- and contrast-to-noise ratios, IQ, and diagnostic certainty are significantly increased in low-kiloelectron volt VMIs (≤60 keV). Interrater agreement was excellent (ĸ = 0.89). We developed 2 linear models (R: 0.91-0.97 and R: 0.43-0.91, respectively, P ≤ 0.01), that suggest appropriate window settings. CONCLUSIONS The VMIs from spectral detector computed tomography improve objective and subjective IQ in angiography of the pulmonary arteries, if window settings are adjusted; they can be automatically estimated using reported linear models.
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Katsura M, Sato J, Akahane M, Kunimatsu A, Abe O. Current and Novel Techniques for Metal Artifact Reduction at CT: Practical Guide for Radiologists. Radiographics 2018. [PMID: 29528826 DOI: 10.1148/rg.2018170102] [Citation(s) in RCA: 166] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Artifacts caused by metallic implants appear as dark and bright streaks at computed tomography (CT), which severely degrade the image quality and decrease the diagnostic value of the examination. When x-rays pass through a metal object, depending on its size and composition, different physical effects negatively affect the measurements in the detector, most notably the effects of photon starvation and beam hardening. To improve image quality and recover information about underlying structures, several artifact reduction methods have been introduced in modern CT systems. Projection-based metal artifact reduction (MAR) algorithms act in projection space and replace corrupted projections caused by metal with interpolation from neighboring uncorrupted projections. MAR algorithms primarily suppress artifacts that are due to photon starvation. The dual-energy CT technique is characterized by data acquisition at two different energy spectra. Dual-energy CT provides synthesized virtual monochromatic images at different photon energy (kiloelectron volt) levels, and virtual monochromatic images obtained at high kiloelectron volt levels are known to reduce the effects of beam hardening. In clinical practice, although MAR algorithms can be applied after image acquisition, the decision whether to apply dual-energy CT for the patient usually needs to be made before image acquisition. Radiologists should be more familiar with the clinical and technical features of each method and should be able to choose the optimal method according to the clinical situation. ©RSNA, 2018.
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Affiliation(s)
- Masaki Katsura
- From the Department of Radiology, Graduate School of Medicine (M.K., J.S., O.A.), and the Department of Radiology, Institute of Medical Science (A.K.), the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan; and the Department of Radiology, School of Medicine, International University of Health and Welfare, Chiba, Japan (M.A.)
| | - Jiro Sato
- From the Department of Radiology, Graduate School of Medicine (M.K., J.S., O.A.), and the Department of Radiology, Institute of Medical Science (A.K.), the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan; and the Department of Radiology, School of Medicine, International University of Health and Welfare, Chiba, Japan (M.A.)
| | - Masaaki Akahane
- From the Department of Radiology, Graduate School of Medicine (M.K., J.S., O.A.), and the Department of Radiology, Institute of Medical Science (A.K.), the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan; and the Department of Radiology, School of Medicine, International University of Health and Welfare, Chiba, Japan (M.A.)
| | - Akira Kunimatsu
- From the Department of Radiology, Graduate School of Medicine (M.K., J.S., O.A.), and the Department of Radiology, Institute of Medical Science (A.K.), the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan; and the Department of Radiology, School of Medicine, International University of Health and Welfare, Chiba, Japan (M.A.)
| | - Osamu Abe
- From the Department of Radiology, Graduate School of Medicine (M.K., J.S., O.A.), and the Department of Radiology, Institute of Medical Science (A.K.), the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan; and the Department of Radiology, School of Medicine, International University of Health and Welfare, Chiba, Japan (M.A.)
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Dane B, Patel H, O'Donnell T, Girvin F, Brusca-Augello G, Alpert JB, Niu B, Attia M, Babb J, Ko JP. Image Quality on Dual-energy CTPA Virtual Monoenergetic Images: Quantitative and Qualitative Assessment. Acad Radiol 2018; 25:1075-1086. [PMID: 29398436 DOI: 10.1016/j.acra.2017.12.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 12/08/2017] [Accepted: 12/17/2017] [Indexed: 01/14/2023]
Abstract
RATIONALE AND OBJECTIVES This study aims to determine the optimal photon energy for image quality of the pulmonary arteries (PAs) on dual-energy computed tomography (CT) pulmonary angiography (CTPA) utilizing low volumes of iodinated contrast. MATERIALS AND METHODS The study received institutional review board exemption and was Health Insurance Portability and Accountability Act compliant. Adults (n = 56) who underwent dual-energy CTPA with 50-60 cc of iodinated contrast on a third-generation dual-source multidetector CT were retrospectively and consecutively identified. Twelve virtual monoenergetic kiloelectron volt (keV) image data sets (40-150 keV, 10-keV increments) were generated with a second-generation noise-reducing algorithm. Standard regions of interest were placed on main, right, left, and right interlobar pulmonary arteries; pectoralis muscle; and extrathoracic air. Attenuation [mean CT number (Hounsfield unit, HU)], noise [standard deviation (HU)], signal to noise (SNR), and contrast to noise ratio were evaluated. Three blinded chest radiologists rated (from 1 to 5, with 5 being the best) randomized monoenergetic and weighted-average images for attenuation and noise. P <.05 was considered significant. RESULTS Region of interest mean CT number increased as keV decreased, with 40 keV having the highest value (P < .001). Mean SNR was highest for 40-60 keV (P <.05) (14.5-14.7) and was higher (P <.05) than all remaining energies (90-150 keV) for all vessel regions combined. Contrast to noise ratio was highest for 40 keV (P <.001) and decreased as keV increased. SNR was highest at 60 and 70 keV, only slightly higher than 40-50 keV (P <.05). Reader scores for 40-50 keV were greater than other energies and weighted-average images (P <.05). CONCLUSIONS Kiloelectron volt images of 40-50 keV from the second-generation algorithm optimize attenuation on dual-energy CTPA and can potentially aid in interpretation and avoiding nondiagnostic examinations.
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Affiliation(s)
- Bari Dane
- Department of Radiology, NYU Langone Health, 660 First Avenue, New York, NY 10016.
| | - Hersh Patel
- Department of Radiology, NYU Langone Health, 660 First Avenue, New York, NY 10016
| | | | - Francis Girvin
- Department of Radiology, NYU Langone Health, 660 First Avenue, New York, NY 10016
| | | | - Jeffrey B Alpert
- Department of Radiology, NYU Langone Health, 660 First Avenue, New York, NY 10016
| | - Bowen Niu
- Department of Radiology, NYU Langone Health, 660 First Avenue, New York, NY 10016
| | | | - James Babb
- Department of Radiology, NYU Langone Health, 660 First Avenue, New York, NY 10016
| | - Jane P Ko
- Department of Radiology, NYU Langone Health, 660 First Avenue, New York, NY 10016
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Parakh A, Macri F, Sahani D. Dual-Energy Computed Tomography: Dose Reduction, Series Reduction, and Contrast Load Reduction in Dual-Energy Computed Tomography. Radiol Clin North Am 2018; 56:601-624. [PMID: 29936950 DOI: 10.1016/j.rcl.2018.03.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Evolution in computed tomography technology and image reconstruction have significantly changed practice. Dual energy computed tomography is being increasingly adopted owing to benefits of material separation, quantification, and improved contrast-to-noise ratio. The radiation dose can match that from single energy computed tomography. Spectral information derived from a polychromatic x-ray beam at different energies yields in image reconstructions that reduce the number of phases in a multiphasic examination and decrease the absolute amount of contrast media. This increased analytical and image processing capability provides new avenues for addressing radiation dose and iodine exposure concerns.
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Affiliation(s)
- Anushri Parakh
- Department of Radiology, Abdominal Imaging Division, Massachusetts General Hospital, White 270, 55 Fruit Street, Boston, MA 02114, USA
| | - Francesco Macri
- Department of Radiology, Abdominal Imaging Division, Massachusetts General Hospital, White 270, 55 Fruit Street, Boston, MA 02114, USA; Department of Radiology, University Hospital of Nimes, Place di Pr Debre, Nimes 30029, France
| | - Dushyant Sahani
- Department of Radiology, Abdominal Imaging Division, Massachusetts General Hospital, White 270, 55 Fruit Street, Boston, MA 02114, USA.
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45
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Virtual Monoenergetic Images From a Novel Dual-Layer Spectral Detector Computed Tomography Scanner in Portal Venous Phase: Adjusted Window Settings Depending on Assessment Focus Are Essential for Image Interpretation. J Comput Assist Tomogr 2018; 42:350-356. [PMID: 29369944 DOI: 10.1097/rct.0000000000000711] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE We aimed to determine optimal window settings for conventional polyenergetic (PolyE) and virtual monoenergetic images (MonoE) derived from abdominal portal venous phase computed tomography (CT) examinations on a novel dual-layer spectral-detector CT (SDCT). METHODS From 50 patients, SDCT data sets MonoE at 40 kiloelectron volt as well as PolyE were reconstructed and best individual window width and level values manually were assessed separately for evaluation of abdominal arteries as well as for liver lesions. Via regression analysis, optimized individual values were mathematically calculated. Subjective image quality parameters, vessel, and liver lesion diameters were measured to determine influences of different W/L settings. RESULTS Attenuation and contrast-to-noise values were significantly higher in MonoE compared with PolyE. Compared with standard settings, almost all adjusted W/L settings varied significantly and yielded higher subjective scoring. No differences were found between manually adjusted and mathematically calculated W/L settings. CONCLUSIONS PolyE and MonoE from abdominal portal venous phase SDCT examinations require appropriate W/L settings depending on reconstruction technique and assessment focus.
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Zhao L, Li F, Zhang Z, Zhang Z, Jiang Y, Wang X, Gu J, Li D. Assessment of an advanced virtual monoenergetic reconstruction technique in cerebral and cervical angiography with third-generation dual-source CT: Feasibility of using low-concentration contrast medium. Eur Radiol 2018; 28:4379-4388. [PMID: 29654560 DOI: 10.1007/s00330-018-5407-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 02/13/2018] [Accepted: 02/22/2018] [Indexed: 12/26/2022]
Abstract
OBJECTIVES To investigate the feasibility of low-concentration contrast media (LC-CM) in cerebral and cervical dual-energy CT angiography (DE-CTA) using an advanced monoenergetic (Mono+) reconstruction technique. METHODS Sixty-five consecutive patients prospectively selected to undergo cerebral and cervical DE-CTA were randomised into two groups: 32 patients (63.7 ± 9.7 years) in the high-concentration contrast medium (HC-CM) group with iopromide 370 and 33 patients (60.7 ± 10.8 years) in the low-concentration contrast medium (LC-CM) group with iodixanol 270. Traditional monoenergetic (Mono) and Mono+ images from 40 to 100 keV levels (at 10-keV intervals) and the standard mixed (Mixed, 120 kVp equivalent) images were reconstructed. Subjective image quality parameters included the contrast-to-noise ratio (CNR) and objective image quality parameters were evaluated and compared between the two groups. RESULTS The 40-keV Mono+ images in the LC-CM group showed comparable objective CNR (common carotid arteries: 83.7 ± 24.5 vs. 78.1 ± 23.2; internal carotid arteries: 82.2 ± 26.8 vs. 76.8 ± 24.1; middle cerebral arteries: 72.5 ± 24.6 vs. 70.6 ± 19.2; all p > 0.05) and subjective image scores (3.95 ± 0.19 vs. 3.83 ± 0.35; p > 0.05) compared with Mixed images in the HC-CM group. CONCLUSION The Mono+ reconstruction technique could reduce the concentration of iodinated CM in the diagnosis of cerebral and cervical angiography. KEY POINTS • Mono+ shows decreased noise and superior CNR compared with Mono. • The 40-keV Mono+ images show the highest CNR in the LC-CM group. • The Mono+ reconstruction technique could reduce the concentration of iodinated CM.
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Affiliation(s)
- Lu Zhao
- Department of Radiology, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Fengtan Li
- Department of Radiology, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Zewei Zhang
- Department of Radiology, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Zhang Zhang
- Department of Radiology, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Yingjian Jiang
- Department of Radiology, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Xinyu Wang
- Department of Radiology, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Jun Gu
- Siemens Healthineers, Beijing, 100102, China
| | - Dong Li
- Department of Radiology, Tianjin Medical University General Hospital, Tianjin, 300052, China.
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Poly-energetic and virtual mono-energetic images from a novel dual-layer spectral detector CT: optimization of window settings is crucial to improve subjective image quality in abdominal CT angiographies. Abdom Radiol (NY) 2018; 43:742-750. [PMID: 28677003 DOI: 10.1007/s00261-017-1241-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
PURPOSE We aimed to determine optimal window settings for poly-energetic (PolyE) and virtual mono-energetic images (MonoE) derived from abdominal angiographic studies on a novel dual-layer spectral detector CT (SDCT) system. METHODS From 50 patients, SDCT datasets PolyE and MonoE at 70 and 40 keV levels were reconstructed and best individual window width and level (BI-W/L) manually assessed. Through regression analysis, the so-called optimized individual (OI-W/L) values were obtained. Subjective image quality parameters and vessel diameters were measured to determine influences of different W/L settings. RESULTS Image noise was lower and attenuation and contrast-to-noise ratio were higher in MonoE compared to PolyE (all p ≤ 0.002). Mean BI-W/L values for PolyE, 70, and 40 keV were 637/284, 647/291, and 1568/691, respectively. Mean OI-W/L values were 631/276, 628/286, and 1516/667, respectively. Compared to standard settings, all adjusted W/L settings varied significantly and yielded higher subjective scoring. No between-group differences were found between manually adjusted and mathematically calculated W/L settings. CONCLUSION PolyE and MonoE from abdominal angiographic SDCT studies require appropriate W/L settings especially at low energy reconstruction levels. Individual adjustment reaches the best image quality but is time consuming. From our data, predefined W/L settings of 640/280 (PolyE/MonoE 70 keV) and 1570/690 (MonoE 40 keV) as a non-individualized starting point for abdominal angiographic studies from the novel SDCT system are suggested.
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De Cecco CN, Caruso D, Schoepf UJ, De Santis D, Muscogiuri G, Albrecht MH, Meinel FG, Wichmann JL, Burchett PF, Varga-Szemes A, Sheafor DH, Hardie AD. A noise-optimized virtual monoenergetic reconstruction algorithm improves the diagnostic accuracy of late hepatic arterial phase dual-energy CT for the detection of hypervascular liver lesions. Eur Radiol 2018; 28:3393-3404. [PMID: 29460075 DOI: 10.1007/s00330-018-5313-6] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 12/05/2017] [Accepted: 01/03/2018] [Indexed: 01/24/2023]
Abstract
OBJECTIVES To assess the image quality and diagnostic accuracy of a noise-optimized virtual monoenergetic imaging (VMI+) algorithm compared with standard virtual monoenergetic imaging (VMI) and linearly-blended (M_0.6) reconstructions for the detection of hypervascular liver lesions in dual-energy CT (DECT). METHODS Thirty patients who underwent clinical liver MRI were prospectively enrolled. Within 60 days of MRI, arterial phase DECT images were acquired on a third-generation dual-source CT and reconstructed with M_0.6, VMI and VMI+ algorithms from 40 to 100 keV in 5-keV intervals. Liver parenchyma and lesion contrast-to-noise-ratios (CNR) were calculated. Two radiologists assessed image quality. Lesion sensitivity, specificity and area under the receiver operating characteristic curves (AUCs) were calculated for the three algorithms with MRI as the reference standard. RESULTS VMI+ datasets from 40 to 60 keV provided the highest liver parenchyma and lesion CNR (p ≤0.021); 50 keV VMI+ provided the highest subjective image quality (4.40±0.54), significantly higher compared to VMI and M_0.6 (all p <0.001), and the best diagnostic accuracy in < 1-cm diameter lesions (AUC=0.833 vs. 0.777 and 0.749, respectively; p ≤0.003). CONCLUSIONS 50-keV VMI+ provides superior image quality and diagnostic accuracy for the detection of hypervascular liver lesions with a diameter < 1cm compared to VMI or M_0.6 reconstructions. KEY POINTS • Low-keV VMI+ are characterized by higher contrast resulting from maximum iodine attenuation. • VMI+ provides superior image quality compared with VMI or M_0.6. • 50-keV_VMI+ provides higher accuracy for the detection of hypervascular liver lesions < 1cm.
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Affiliation(s)
- Carlo N De Cecco
- Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC, USA
| | - Damiano Caruso
- Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC, USA.,Department of Radiological Sciences, Oncological and Pathological Sciences University of Rome "Sapienza", Latina, Italy
| | - U Joseph Schoepf
- Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC, USA.
| | - Domenico De Santis
- Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC, USA.,Department of Radiological Sciences, Oncological and Pathological Sciences University of Rome "Sapienza", Latina, Italy
| | - Giuseppe Muscogiuri
- Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC, USA.,Department of Clinical and Molecular Medicine, University of Rome "Sapienza", Rome, Italy
| | - Moritz H Albrecht
- Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC, USA.,Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt am Main, Germany
| | - Felix G Meinel
- Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC, USA.,Institute for Clinical Radiology, Ludwig Maximilian University Hospital, Munich, Germany
| | - Julian L Wichmann
- Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC, USA.,Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt am Main, Germany
| | - Philip F Burchett
- Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC, USA
| | - Akos Varga-Szemes
- Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC, USA
| | - Douglas H Sheafor
- Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC, USA
| | - Andrew D Hardie
- Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC, USA
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Improved Opacification of a Suboptimally Enhanced Pulmonary Artery in Chest CT: Experience Using a Dual-Layer Detector Spectral CT. AJR Am J Roentgenol 2018; 210:734-741. [PMID: 29446668 DOI: 10.2214/ajr.17.18537] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVE The objective of our study was to evaluate the quality of virtual monoenergetic imaging (VMI) from dual-layer detector spectral CT and the effect of virtual monoenergetic images obtained at low energies on the detection of pulmonary embolism (PE) in patients with a suboptimally enhanced pulmonary artery on chest CT. MATERIALS AND METHODS Of 1552 consecutive chest CT examinations performed with dual-layer detector spectral CT using a routine protocol with a tube voltage of 120 kVp, 79 examinations with suboptimal enhancement of the pulmonary artery (i.e., mean attenuation of pulmonary artery ≤ 180 HU) were included. The mean attenuation of the pulmonary artery, noise, contrast-to-noise ratio (CNR), and signal-to-noise ratio (SNR) of virtual monoenergetic images obtained at 40-200 keV were compared with those of the conventional 120-kVp images. The virtual monoenergetic images with the best CNR were compared with the 120-kVp images with regard to subjective image quality and diagnostic accuracy for detecting PE. RESULTS Sufficient attenuation of the pulmonary artery (> 180 HU) was obtained using VMI for 78 of the 79 examinations. The noise levels of the virtual monoenergetic images were gradually increased with decreasing energy level (i.e., kiloelectron volt setting). The CNR and SNR of virtual monoenergetic images at 40-65 keV were significantly higher (both, p < 0.001) than the CNR and SNR of the 120-kVp images. The CNR was the highest at 40 keV for all cases. Diagnostic accuracy for detecting PE was significantly higher for 40-keV images (reader 1: AUC = 0.992, p = 0.033; reader 2: AUC = 0.986, p = 0.043) than for 120-kVp images (reader 1, AUC = 0.911; reader 2, AUC = 0.933). The subjective quality was not different between these two images. CONCLUSION In chest CT examinations in which the pulmonary artery is suboptimally enhanced, obtaining virtual monoenergetic images at a low energy setting using dual-layer detector spectral CT allows sufficient attenuation of the pulmonary artery to be achieved while preserving image quality and increasing diagnostic performance for detecting PE.
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Toia GV, Kim S, Dighe MK, Mileto A. Dual-Energy Computed Tomography in Body Imaging. Semin Roentgenol 2018; 53:132-146. [PMID: 29861005 DOI: 10.1053/j.ro.2018.02.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Giuseppe V Toia
- Body Imaging Section, Department of Radiology, University of Washington School of Medicine, Seattle, WA 98195
| | - Sooah Kim
- Body Imaging Section, Department of Radiology, University of Washington School of Medicine, Seattle, WA 98195
| | - Manjiri K Dighe
- Body Imaging Section, Department of Radiology, University of Washington School of Medicine, Seattle, WA 98195
| | - Achille Mileto
- Body Imaging Section, Department of Radiology, University of Washington School of Medicine, Seattle, WA 98195.
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