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Turrion Gomollon AM, Mergen V, Sartoretti T, Polacin M, Nakhostin D, Puippe G, Alkadhi H, Euler A. Photon-Counting Detector CT Angiography for Endoleak Detection After Endovascular Aortic Repair: Triphasic CT With True Noncontrast Versus Biphasic CT With Virtual Noniodine Imaging. Invest Radiol 2023; 58:816-821. [PMID: 37358359 PMCID: PMC10581441 DOI: 10.1097/rli.0000000000000993] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 04/25/2023] [Indexed: 06/27/2023]
Abstract
OBJECTIVES The aim of this study was to compare image quality and endoleak detection after endovascular abdominal aortic aneurysm repair between a triphasic computed tomography (CT) with true noncontrast (TNC) and a biphasic CT with virtual noniodine (VNI) images on photon-counting detector CT (PCD-CT). MATERIALS AND METHODS Adult patients after endovascular abdominal aortic aneurysm repair who received a triphasic examination (TNC, arterial, venous phase) on a PCD-CT between August 2021 and July 2022 were retrospectively included. Endoleak detection was evaluated by 2 blinded radiologists on 2 different readout sets (triphasic CT with TNC-arterial-venous vs biphasic CT with VNI-arterial-venous). Virtual noniodine images were reconstructed from the venous phase. The radiologic report with additional confirmation by an expert reader served as reference standard for endoleak presence. Sensitivity, specificity, and interreader agreement (Krippendorf α) were calculated. Image noise was assessed subjectively in patients using a 5-point scale and objectively calculating the noise power spectrum in a phantom. RESULTS One hundred ten patients (7 women; age, 76 ± 8 years) with 41 endoleaks were included. Endoleak detection was comparable between both readout sets with a sensitivity and specificity of 0.95/0.84 (TNC) versus 0.95/0.86 (VNI) for reader 1 and 0.88/0.98 (TNC) versus 0.88/0.94 (VNI) for reader 2. Interreader agreement for endoleak detection was substantial (TNC: 0.716, VNI: 0.756). Subjective image noise was comparable between TNC and VNI (4; IQR [4, 5] vs 4; IQR [4, 5], P = 0.44). In the phantom, noise power spectrum peak spatial frequency was similar between TNC and VNI (both f peak = 0.16 mm -1 ). Objective image noise was higher in TNC (12.7 HU) as compared with VNI (11.5 HU). CONCLUSIONS Endoleak detection and image quality were comparable using VNI images in biphasic CT as compared with TNC images in triphasic CT offering the possibility to reduce scan phases and radiation exposure.
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Wang A, Li W, Huang W, Luo M, Xiao W, Qin C, Dong S, Liu H, Li Z, Diao K. Dual-layer spectral computed tomography aortography using a seventy-five-percent-reduced iodine dose protocol and multiparameter spectral imaging: comparison with conventional computed tomography imaging. Quant Imaging Med Surg 2023; 13:6456-6467. [PMID: 37869326 PMCID: PMC10585532 DOI: 10.21037/qims-23-101] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 08/08/2023] [Indexed: 10/24/2023]
Abstract
Background Computed tomography angiography (CTA) is the recommended diagnostic and follow-up imaging modality for acute aortic dissection (AD). However, the high-contrast medium burden associated with repeated CT aortography follow-ups remains a significant concern. This prospective study aimed to assess whether an ultra-low contrast dose (75% cutoff) aortic CTA protocol on dual-layer spectral CT could achieve comparable image quality with the full dose protocol. We also investigated the image quality of the virtual noncontrast (VNC) images derived from the ultra-low dose protocol. Methods This study included 37 consecutive patients who were referred to aortic CTA from May 2022 to August 2022. The enrolled patients underwent full-dose contrast CTA and ultra-low dose (reduced to 25% of conventional) contrast CTA on dual-layer spectral CT in 1 day. Virtual monochromatic images (VMIs) were reconstructed with 40 and 70 keV. The VNC images were reconstructed for both protocols. Objective image quality evaluation, recorded as signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs), was compared between the groups using 1-way analysis of variance and post hoc analysis with Bonferroni correction. Subjective image quality was also compared between the groups. Finally, VNC images derived from the low-dose (VNClow) and full-dose (VNCfull) protocols were compared to the true noncontrast (TNC) images. Results Neither CNR nor SNR was lower for the 40-keV images reconstructed from the ultra-low dose group compared to the conventional images. Both were significantly higher than those of the 70-keV images. Regarding subjective image quality, vessel enhancement was not significantly different between the 40-keV VMI and full-dose images [ascending aorta (AAO): 4.37±0.46 vs. 4.57±0.48, P=0.096; brachiocephalic arteries: 4.34±0.45 vs. 4.51±0.49, P=0.152; abdominal aortic side branch: 4.42±0.48 vs. 4.51±0.49, P=0.480]. The VNClow images were similar to the TNC images but significantly different from the VNCfull images (P<0.001). Conclusions Ultra-low contrast aortic CTA with a 75%-reduced iodine dose using dual-layer spectral CT and the derived VNC achieved image quality comparable to that of conventional CTA and TNC images.
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Affiliation(s)
- Aijie Wang
- Department of Radiology, West China Hospital of Sichuan University, Chengdu, China
| | - Wanjiang Li
- Department of Radiology, West China Hospital of Sichuan University, Chengdu, China
| | - Wenyu Huang
- West China School of Medicine, West China Hospital of Sichuan University, Chengdu, China
| | - Mao Luo
- Department of Radiology, West China Hospital of Sichuan University, Chengdu, China
| | - Wendan Xiao
- Department of Radiology, West China Hospital of Sichuan University, Chengdu, China
| | - Chaoyi Qin
- Department of Cardiovascular Surgery, West China Hospital of Sichuan University, Chengdu, China
| | - Shushan Dong
- Clinical Science, Philips Healthcare, Beijing, China
| | - Haiwei Liu
- Advanced Clinical Application, Philips Healthcare, Beijing, China
| | - Zhenlin Li
- Department of Radiology, West China Hospital of Sichuan University, Chengdu, China
| | - Kaiyue Diao
- Department of Radiology, West China Hospital of Sichuan University, Chengdu, China
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Decker JA, Huber A, Senel F, Risch F, Bette S, Braun F, Becker J, Popp D, Haerting M, Jehs B, Rippel K, Wollny C, Scheurig-Muenkler C, Kroencke TJ, Schwarz F. Anemia detection and quantification in contrast-enhanced CT scans on a novel photon-counting detector CT: A prospective proof-of-concept study. Eur J Radiol 2023; 166:110967. [PMID: 37487433 DOI: 10.1016/j.ejrad.2023.110967] [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: 04/18/2023] [Revised: 05/31/2023] [Accepted: 07/07/2023] [Indexed: 07/26/2023]
Abstract
PURPOSE To correlate CT values of the blood pool on VNC series with serum hemoglobin values for the detection of anemia in oncologic patients undergoing contrast-enhanced PCD-CT scans. METHODS This prospective study (NCT04989192) included consecutive oncologic patients undergoing contrast-enhanced CT on a novel PCD-CT system between 08/2021 and 01/2022. The interval between complete blood count (CBC) and CT scan acquisition had to be no more than seven days. CT-values of the blood pool were measured on 70 keV VMI series (CT-values(BP)70keV) and on VNC series (CT-values(BP)VNC) at five anatomic positions (left atrium, left ventricle, main pulmonary artery, ascending and descending aorta) and averaged per patient. Pearson correlation analyses and ROC analyses were performed to identify relations between CT-values(BP)VNC, CBC parameters, and degrees of anemia as defined by the WHO (no anemia, mild, moderate, severe anemia). RESULTS A total of 329 patients (age 68 ± 12 years; 200 men) were included. CT-values(BP)VNC showed a strong linear correlation to serum hemoglobin (r2 = 0.80, p <.001) and hematocrit (r2 = 0.76, p <.001) and were significantly different between anemia subgroups in both women and men (ΔHU: 3.5-11.4; all p <.01). ROC analyses yielded high diagnostic performance for the identification of patients without anemia, patients without and with mild anemia, and patients with severe anemia using gender-specific cutoffs for CT-value(BP)VNC (all AUC's > 0.90). CONCLUSIONS The spectral information inherent in PCD-CT acquisitions allows the detection and quantification of anemia in contrast-enhanced CT acquisitions of oncologic patients with high diagnostic accuracy.
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Affiliation(s)
- Josua A Decker
- Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany.
| | - Adrian Huber
- Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany.
| | - Fevzi Senel
- Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany.
| | - Franka Risch
- Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany.
| | - Stefanie Bette
- Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany.
| | - Franziska Braun
- Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany.
| | - Judith Becker
- Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany.
| | - Daniel Popp
- Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany.
| | - Mark Haerting
- Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany.
| | - Bertram Jehs
- Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany.
| | - Katharina Rippel
- Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany.
| | - Claudia Wollny
- Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany.
| | - Christian Scheurig-Muenkler
- Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany.
| | - Thomas J Kroencke
- Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany.
| | - Florian Schwarz
- Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany; Medical Faculty, Ludwig Maximilian University Munich, Bavariaring 19, 80336 Munich, Germany; Institute for Radiology, DONAUISAR Hospital Deggendorf-Dingolfing-Landau, Perlasberger Str. 41, 94469 Deggendorf, Germany.
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Grkovski R, Acu L, Ahmadli U, Nakhostin D, Thurner P, Wacht L, Kulcsár Z, Alkadhi H, Winklhofer S. Dual-Energy Computed Tomography in Stroke Imaging : Value of a New Image Acquisition Technique for Ischemia Detection after Mechanical Thrombectomy. Clin Neuroradiol 2023; 33:747-754. [PMID: 36862231 PMCID: PMC10450017 DOI: 10.1007/s00062-023-01270-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 01/24/2023] [Indexed: 03/03/2023]
Abstract
OBJECTIVE To assess if a new dual-energy computed tomography (DECT) technique enables an improved visualization of ischemic brain tissue after mechanical thrombectomy in acute stroke patients. MATERIAL AND METHODS The DECT head scans with a new sequential technique (TwinSpiral DECT) were performed in 41 patients with ischemic stroke after endovascular thrombectomy and were retrospectively included. Standard mixed and virtual non-contrast (VNC) images were reconstructed. Infarct visibility and image noise were assessed qualitatively by two readers using a 4-point Likert scale. Quantitative Hounsfield units (HU) were used to assess density differences of ischemic brain tissue versus healthy tissue on the non-affected contralateral hemisphere. RESULTS Infarct visibility was significantly better in VNC compared to mixed images for both readers R1 (VNC: median 1 (range 1-3), mixed: median 2 (range 1-4), p < 0.05) and R2 (VNC: median 2 (range 1-3), mixed: 2 (range 1-4), p < 0.05). Qualitative image noise was significantly higher in VNC compared to mixed images for both readers R1 (VNC: median 3, mixed: 2) and R2 (VNC: median 2, mixed: 1, p < 0.05, each). Mean HU were significantly different between the infarcted tissue and the reference healthy brain tissue on the contralateral hemisphere in VNC (infarct 24 ± 3) and mixed images (infarct 33 ± 5, p < 0.05, each). The mean HU difference between ischemia and reference in VNC images (mean 8 ± 3) was significantly higher (p < 0.05) compared to the mean HU difference in mixed images (mean 5 ± 4). CONCLUSION TwinSpiral DECT allows an improved qualitative and quantitative visualization of ischemic brain tissue in ischemic stroke patients after endovascular treatment.
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Affiliation(s)
- Risto Grkovski
- Department of Neuroradiology, University Hospital Zurich, University of Zurich, Frauenklinikstrasse 10, 8091, Zurich, Switzerland
- Faculty of Medicine, University of Ljubljana, Vrazov trg 2, 1000, Ljubljana, Slovenia
- Department of Radiology, University Medical Centre Maribor, Ljubljanska ulica 5, 2000, Maribor, Slovenia
| | - Leyla Acu
- Department of Neuroradiology, University Hospital Zurich, University of Zurich, Frauenklinikstrasse 10, 8091, Zurich, Switzerland
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Rämistrasse 100, 8091, Zurich, Switzerland
| | - Uzeyir Ahmadli
- Department of Neuroradiology, University Hospital Zurich, University of Zurich, Frauenklinikstrasse 10, 8091, Zurich, Switzerland
| | - Dominik Nakhostin
- Department of Neuroradiology, University Hospital Zurich, University of Zurich, Frauenklinikstrasse 10, 8091, Zurich, Switzerland
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Rämistrasse 100, 8091, Zurich, Switzerland
| | - Patrick Thurner
- Department of Neuroradiology, University Hospital Zurich, University of Zurich, Frauenklinikstrasse 10, 8091, Zurich, Switzerland
| | - Lorenz Wacht
- Department of Neuroradiology, University Hospital Zurich, University of Zurich, Frauenklinikstrasse 10, 8091, Zurich, Switzerland
| | - Zsolt Kulcsár
- Department of Neuroradiology, University Hospital Zurich, University of Zurich, Frauenklinikstrasse 10, 8091, Zurich, Switzerland
| | - Hatem Alkadhi
- Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Rämistrasse 100, 8091, Zurich, Switzerland
| | - Sebastian Winklhofer
- Department of Neuroradiology, University Hospital Zurich, University of Zurich, Frauenklinikstrasse 10, 8091, Zurich, Switzerland.
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Comparative study of true and virtual non-contrast imaging generated from dual-layer spectral CT in patients with upper aerodigestive tract cancer. Pol J Radiol 2022; 87:e678-e687. [PMID: 36643004 PMCID: PMC9834071 DOI: 10.5114/pjr.2022.123829] [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: 04/18/2022] [Accepted: 08/08/2022] [Indexed: 01/12/2023] Open
Abstract
Purpose Dual-layer spectral computed tomography (DLSCT) is a novel CT platform of dual-energy CT. Virtual non-contrast (VNC) imaging theoretically resembles true non-contrast (TNC) imaging by subtracting iodine attenuation from post-contrast data. We aimed to compare qualitative and quantitative datasets between TNC and VNC in patients with upper aerodigestive tract cancer (UATC) and to evaluate the potential radiation dose reduction obtained by omitting the TNC phase. Material and methods The study included 61 patients with UATC who underwent DLSCT. The CT protocol included TNC and post-contrast phases. The VNC images were reconstructed from the post-contrast phase. The differences of mean CT attenuation values, imaging noise, and image quality for TNC and VNC images were compared. The effective radiation doses of a biphasic TNC and post-contrast CT protocol were compared with a single-phase protocol (post-contrast CT with VNC reconstruction). Results There were a total of 732 ROIs from TNC and VNC. There was no statistical difference in the mean CT attenuation values between TNC and VNC images for all tissue types (p = 0.09-0.44), except for the buccal fat pad. Overall, 85.3% of cases revealed a difference of less than 10 HU. There was no significant difference in mean imaging noise (p = 0.5455) and image quality (p = 0.3214) between 2 acquisitions. All VNC images had acceptable quality for diagnostic purposes. The potential dose reduction by omitting the TNC was 49.5 ± 3.5%. Conclusion VNC could replace TNC images in patients with UATC, with good image quality and the advantage of radiation dose reduction.
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Kauw F, Ding VY, Dankbaar JW, van Ommen F, Zhu G, Boothroyd DB, Wolman DN, Molvin L, de Jong HWAM, Kappelle LJ, Velthuis BK, Heit JJ, Wintermark M. Detection of Early Ischemic Changes with Virtual Noncontrast Dual-Energy CT in Acute Ischemic Stroke: A Noninferiority Analysis. AJNR Am J Neuroradiol 2022; 43:1259-1264. [PMID: 35953275 PMCID: PMC9451625 DOI: 10.3174/ajnr.a7600] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 06/17/2022] [Indexed: 01/26/2023]
Abstract
BACKGROUND AND PURPOSE Dual-energy virtual NCCT has the potential to replace conventional NCCT to detect early ischemic changes in acute ischemic stroke. In this study, we evaluated whether virtual NCCT is noninferior compared with standard linearly blended NCCT, a surrogate of conventional NCCT, regarding the detection of early ischemic changes with ASPECTS. MATERIALS AND METHODS Adult patients who presented with suspected acute ischemic stroke and who underwent dual-energy NCCT and CTA and brain MR imaging within 48 hours were included. Standard linearly blended images were reconstructed to match a conventional NCCT. Virtual NCCT images were reconstructed from CTA. ASPECTS was evaluated on conventional NCCT, virtual NCCT, and DWI, which served as the reference standard. Agreement between CT assessments and the reference standard was evaluated with the Lin concordance correlation coefficient. Noninferiority was assessed with bootstrapped estimates of the differences in ASPECTS between conventional and virtual NCCT with 95% CIs. RESULTS Of the 193 included patients, 100 patients (52%) had ischemia on DWI. Compared with the reference standard, the ASPECTS concordance correlation coefficient for conventional and virtual NCCT was 0.23 (95% CI, 0.15-0.32) and 0.44 (95% CI, 0.33-0.53), respectively. The difference in the concordance correlation coefficient between virtual and conventional NCCT was 0.20 (95% CI, 0.01-0.39) and did not cross the prespecified noninferiority margin of -0.10. CONCLUSIONS Dual-energy virtual NCCT is noninferior compared with conventional NCCT for the detection of early ischemic changes with ASPECTS.
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Affiliation(s)
- F Kauw
- From the Departments of Radiology (F.K., F.v.O., G.Z., D.N.W., L.M., J.J.H., M.W.)
- Departments of Radiology (F.K., J.W.D., F.v.O., H.W.A.M.d.J., B.K.V.)
- Neurology (F.K., L.J.K.), University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - V Y Ding
- Medicine (V.Y.D., D.B.B.), Stanford University, Stanford, California
| | - J W Dankbaar
- Departments of Radiology (F.K., J.W.D., F.v.O., H.W.A.M.d.J., B.K.V.)
| | - F van Ommen
- From the Departments of Radiology (F.K., F.v.O., G.Z., D.N.W., L.M., J.J.H., M.W.)
- Departments of Radiology (F.K., J.W.D., F.v.O., H.W.A.M.d.J., B.K.V.)
| | - G Zhu
- From the Departments of Radiology (F.K., F.v.O., G.Z., D.N.W., L.M., J.J.H., M.W.)
| | - D B Boothroyd
- Medicine (V.Y.D., D.B.B.), Stanford University, Stanford, California
| | - D N Wolman
- From the Departments of Radiology (F.K., F.v.O., G.Z., D.N.W., L.M., J.J.H., M.W.)
| | - L Molvin
- From the Departments of Radiology (F.K., F.v.O., G.Z., D.N.W., L.M., J.J.H., M.W.)
| | - H W A M de Jong
- Departments of Radiology (F.K., J.W.D., F.v.O., H.W.A.M.d.J., B.K.V.)
| | - L J Kappelle
- Neurology (F.K., L.J.K.), University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - B K Velthuis
- Departments of Radiology (F.K., J.W.D., F.v.O., H.W.A.M.d.J., B.K.V.)
| | - J J Heit
- From the Departments of Radiology (F.K., F.v.O., G.Z., D.N.W., L.M., J.J.H., M.W.)
| | - M Wintermark
- From the Departments of Radiology (F.K., F.v.O., G.Z., D.N.W., L.M., J.J.H., M.W.)
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Lee MH, Park HJ, Kim JN, Kim MS, Hong SW, Park JH, Kang CH. Virtual non-contrast images from dual-energy CT angiography of the abdominal aorta and femoral arteries: comparison with true non-contrast CT images. Br J Radiol 2022; 95:20220378. [PMID: 36039820 PMCID: PMC9815733 DOI: 10.1259/bjr.20220378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 08/01/2022] [Accepted: 08/19/2022] [Indexed: 01/13/2023] Open
Abstract
OBJECTIVES To assess whether virtual non-contrast (VNC) computed tomography (CT) images acquired from dual-energy CT (DECT) have sufficient image quality to replace true non-contrast (TNC) CT images in CT angiography (CTAG). METHODS This study enrolled 63 consecutive patients who underwent a CTAG that included a single-energy non-contrast scan, followed by a post-contrast DECT scan. Comparison of attenuation and noise between TNC and VNC images was made by drawing circular regions of interest (ROI) on a picture archiving and communication system (PACS) workstation within the aortic lumen at the levels of the renal arteries, the aortic bifurcation and right femoral artery. Mean attenuation and image noise (one standard deviation) were registered in Hounsfield units (HU). The VNC images were subjectively evaluated for artifacts such as subtraction of calcifications or architectural distortion based on TNC image as a standard of reference. RESULTS Most attenuations of the VNCs were higher than TNC, except right femoral artery of reader 2. Most image noises of TNC were higher than VNC, except abdominal aorta in reader 1. In qualitative image analysis, mean scores of VNC according to the 5-point scale were 3.68 and 3.63 (reader 1 and reader 2, respectively) which mean good to excellent to diagnose. CONCLUSION HUs and VNC image noises are different from TNC images in CTAG. VNC images have sufficient image quality to replace TNC images in the diagnosis of calcific lesions. ADVANCES IN KNOWLEDGE VNC images acquired from DECT have image quality adequate to replace TNC images in the diagnosis of the calcific lesion on the CTAG. VNC images based on DECT can avoid excessive and unnecessary patient exposure to radiation during CTAG.
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Affiliation(s)
- Min Hee Lee
- Department of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Hee Jin Park
- Department of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Ji Na Kim
- Department of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Myung Sub Kim
- Department of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Seok Woo Hong
- Department of Orthopaedic Surgery, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Jai Hyung Park
- Department of Orthopaedic Surgery, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Chang Ho Kang
- Department of Radiology, Korea University Anam Hospital, Seoul, Korea
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Decker JA, Bette S, Scheurig-Muenkler C, Jehs B, Risch F, Woźnicki P, Braun FM, Haerting M, Wollny C, Kroencke TJ, Schwarz F. Virtual Non-Contrast Reconstructions of Photon-Counting Detector CT Angiography Datasets as Substitutes for True Non-Contrast Acquisitions in Patients after EVAR-Performance of a Novel Calcium-Preserving Reconstruction Algorithm. Diagnostics (Basel) 2022; 12:558. [PMID: 35328111 PMCID: PMC8946873 DOI: 10.3390/diagnostics12030558] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 02/17/2022] [Accepted: 02/19/2022] [Indexed: 02/01/2023] Open
Abstract
The purpose of this study was to evaluate virtual-non contrast reconstructions of Photon-Counting Detector (PCD) CT-angiography datasets using a novel calcium-preserving algorithm (VNCPC) vs. the standard algorithm (VNCConv) for their potential to replace unenhanced acquisitions (TNC) in patients after endovascular aneurysm repair (EVAR). 20 EVAR patients who had undergone CTA (unenhanced and arterial phase) on a novel PCD-CT were included. VNCConv- and VNCPC-series were derived from CTA-datasets and intraluminal signal and noise compared. Three readers evaluated image quality, contrast removal, and removal of calcifications/stent parts and assessed all VNC-series for their suitability to replace TNC-series. Image noise was higher in VNC- than in TNC-series (18.6 ± 5.3 HU, 16.7 ± 7.1 HU, and 14.9 ± 7.1 HU for VNCConv-, VNCPC-, and TNC-series, p = 0.006). Subjective image quality was substantially higher in VNCPC- than VNCConv-series (4.2 ± 0.9 vs. 2.5 ± 0.6; p < 0.001). Aortic contrast removal was complete in all VNC-series. Unlike in VNCConv-reconstructions, only minuscule parts of stents or calcifications were erroneously subtracted in VNCPC-reconstructions. Readers considered 95% of VNCPC-series fully or mostly suited to replace TNC-series; for VNCConv-reconstructions, however, only 75% were considered mostly (and none fully) suited for TNC-replacement. VNCPC-reconstructions of PCD-CT-angiography datasets have excellent image quality with complete contrast removal and only minimal erroneous subtractions of stent parts/calcifications. They could replace TNC-series in almost all cases.
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Affiliation(s)
- Josua A. Decker
- Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany; (J.A.D.); (S.B.); (C.S.-M.); (B.J.); (F.R.); (P.W.); (F.M.B.); (M.H.); (C.W.); (F.S.)
| | - Stefanie Bette
- Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany; (J.A.D.); (S.B.); (C.S.-M.); (B.J.); (F.R.); (P.W.); (F.M.B.); (M.H.); (C.W.); (F.S.)
| | - Christian Scheurig-Muenkler
- Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany; (J.A.D.); (S.B.); (C.S.-M.); (B.J.); (F.R.); (P.W.); (F.M.B.); (M.H.); (C.W.); (F.S.)
| | - Bertram Jehs
- Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany; (J.A.D.); (S.B.); (C.S.-M.); (B.J.); (F.R.); (P.W.); (F.M.B.); (M.H.); (C.W.); (F.S.)
| | - Franka Risch
- Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany; (J.A.D.); (S.B.); (C.S.-M.); (B.J.); (F.R.); (P.W.); (F.M.B.); (M.H.); (C.W.); (F.S.)
| | - Piotr Woźnicki
- Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany; (J.A.D.); (S.B.); (C.S.-M.); (B.J.); (F.R.); (P.W.); (F.M.B.); (M.H.); (C.W.); (F.S.)
| | - Franziska M. Braun
- Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany; (J.A.D.); (S.B.); (C.S.-M.); (B.J.); (F.R.); (P.W.); (F.M.B.); (M.H.); (C.W.); (F.S.)
| | - Mark Haerting
- Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany; (J.A.D.); (S.B.); (C.S.-M.); (B.J.); (F.R.); (P.W.); (F.M.B.); (M.H.); (C.W.); (F.S.)
| | - Claudia Wollny
- Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany; (J.A.D.); (S.B.); (C.S.-M.); (B.J.); (F.R.); (P.W.); (F.M.B.); (M.H.); (C.W.); (F.S.)
| | - Thomas J. Kroencke
- Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany; (J.A.D.); (S.B.); (C.S.-M.); (B.J.); (F.R.); (P.W.); (F.M.B.); (M.H.); (C.W.); (F.S.)
| | - Florian Schwarz
- Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany; (J.A.D.); (S.B.); (C.S.-M.); (B.J.); (F.R.); (P.W.); (F.M.B.); (M.H.); (C.W.); (F.S.)
- Faculty of Medicine, Ludwig Maximilian University of Munich, Geschwister-Scholl-Platz 1, 80539 Munich, Germany
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Synthetic Extracellular Volume Fraction Derived Using Virtual Unenhanced Attenuation of Blood on Dual-Energy Contrast-Enhanced Cardiac CT in Nonischemic Cardiomyopathy. AJR Am J Roentgenol 2021; 218:454-461. [PMID: 34643105 DOI: 10.2214/ajr.21.26654] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Background: Current methods for calculating myocardial extracellular volume fraction (ECV) require blood sampling to obtain serum hematocrit. Synthetic hematocrit and thus synthetic ECV may be derived using unenhanced attenuation of blood. By use of virtual unenhanced (VUE) attenuation of blood, contrast-enhanced dual-energy CT (DECT) may allow synthetic ECV calculations without unenhanced acquisition. Objective: To compare synthetic ECV using synthetic hematocrit derived from VUE images versus conventional ECV using serum hematocrit, both obtained by contrast-enhanced DECT, using MRI-derived ECV as reference. Methods: This retrospective study included 51 patients (26 men, 25 women; mean age 59.9 ± 15.6 years) with nonischemic cardiomyopathy who, as part of an earlier prospective investigation, underwent equilibrium-phase contrast-enhanced cardiac DECT and cardiac MRI, with serum hematocrit measured within 6 hours of both tests. A separate retrospective sample of 198 patients who underwent same-day contrast-enhanced thoracic DECT for suspected pulmonary embolism and serum hematocrit measurement was identified to derive a synthetic hematocrit formula using VUE attenuation of blood by linear regression analysis. In the primary sample, two radiologists independently used DECT iodine maps to obtain conventional ECV using serum hematocrit and synthetic ECV using synthetic hematocrit based on the independently derived formula. Concordance correlation coefficient (CCC) was computed between conventional ECV and synthetic ECV from DECT. Conventional ECV and synthetic ECV from DECT were compared with MRI-derived ECV in Bland-Altman analyses. Results: The linear regression formula for synthetic hematocrit in the independent sample was: synthetic hematocrit = 0.85 x (VUE attenuation of blood) - 5.40. In the primary sample, conventional ECV and synthetic ECV from DECT showed excellent agreement (CCC = 0.95). Bland-Altman analysis showed small bias of -0.44% with 95% limits of agreement from -5.10% to 4.22% between MRI-derived ECV and conventional ECV from DECT, and small bias of -0.78% with 95% limits of agreement from -5.25% to 3.69% between MRI-derived ECV and synthetic ECV from DECT. Conclusion: Synthetic ECV and conventional ECV from DECT show excellent agreement and comparable association with ECV from cardiac MRI. Clinical Impact: Synthetic hematocrit from VUE attenuation of blood may allow myocardial tissue characterization on DECT without inconvenience of blood sampling.
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Harsaker V, Jensen K, Andersen HK, Martinsen AC. Quantitative benchmarking of iodine imaging for two CT spectral imaging technologies: a phantom study. Eur Radiol Exp 2021; 5:24. [PMID: 34159477 PMCID: PMC8219825 DOI: 10.1186/s41747-021-00224-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 05/20/2021] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND The aim of this study was to quantitatively benchmark iodine imaging across specific virtual monoenergetic energy levels, iodine maps and virtual non-contrast images with different phantom sizes and iodine concentrations, using a rapid switching dual-energy CT (DECT) and a dual source DECT, in order to investigate accuracy and potential differences between the technologies. METHODS Solutions of iodine contrast (10, 20, 30, 50, and 100 mg/mL), sterile water and saline were scanned in a phantom on a rapid switching single-source and dual-source DECT scanners from two different vendors. The phantom was equipped with polyurethane rings simulating three body sizes. The datasets were reconstructed in virtual monoenergetic energy levels (70, 80, 90, 100, 110, 120, 130, and 140 keV), virtual non-contrast images and iodine maps. HU and iodine concentrations were measured by placing ROIs in the iodine solutions. RESULTS The iodine concentrations were reproduced with a high degree of accuracy for the single-source DECT (1.8-9.0%), showing a slight dependence on phantom size. The dual source DECT technique showed deviant values (error -33.8 to 12.0%) for high concentrations. In relation to the virtual non-contrast measurements, the images from both vendors were affected by the iodine concentration and phantom size (-127.8 to 539.1 HU). Phantom size did not affect the calculated monoenergetic attenuation values, but the attenuation values varied between the scanners. CONCLUSIONS Quantitative measurements of post-processed images are dependent on the concentration of iodine, the phantom size and different technologies. However, our study indicates that the iodine maps are reliable for quantification of iodine.
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Affiliation(s)
- Vanja Harsaker
- Department of Life Sciences and Health, Oslo Metropolitan University, Box 4, St. Olavs plass, 0130, Oslo, Norway.
| | - Kristin Jensen
- The Department of Diagnostic Physics, Oslo University Hospital, Bygg 20, Gaustad Sykehus, Box 4959 Nydalen, 0424, Oslo, Norway
| | - Hilde Kjernlie Andersen
- The Department of Diagnostic Physics, Oslo University Hospital, Bygg 20, Gaustad Sykehus, Box 4959 Nydalen, 0424, Oslo, Norway
| | - Anne Catrine Martinsen
- Department of Life Sciences and Health, Oslo Metropolitan University, Box 4, St. Olavs plass, 0130, Oslo, Norway
- Sunnaas Rehabilitation Hospital, Bjornemyrvn. 11, 1453, Bjornemyr, Norway
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11
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Noid G, Schott D, Paulson E, Zhu J, Shah J, Li XA. Technical Note: Using virtual noncontrast images from dual-energy CT to eliminate the need of precontrast CT for x-ray radiation treatment planning of abdominal tumors †. Med Phys 2021; 48:1365-1371. [PMID: 33386614 DOI: 10.1002/mp.14702] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Revised: 10/27/2020] [Accepted: 12/09/2020] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Radiation therapy (RT) planning frequently utilizes contrast-enhanced CT. However, dose calculations should not be performed on a contrast-enhanced CT because the patient will not receive bolus during treatment. It is typical to acquire CT twice during RT simulation: once before injection of bolus and once after. The registration between these datasets introduces errors. In this work, we investigate the use of virtual noncontrast images (VNC) derived from dual-energy CT (DECT) to eliminate the precontrast CT and the registration error. METHODS CT datasets, including conventional 120 kVp pre- and postcontrast CTs and postcontrast DECT, acquired for ten pancreatic cancer patients were evaluated. The DECTs were acquired simultaneously using a dual source (DS) CT simulator. VNC and virtual mono-energetic images (VMI) were derived from DECTs. Gross tumor volumes (GTV), planning target volumes (PTV), and organs at risks (OAR) were delineated on the postcontrast CT and then populated to the precontrast CT and the VNC. An IMRT plan (50.4 Gy in 28 fractions) was then optimized on the precontrast CT. Dose distributions were recalculated on the VNC images. Contours from the pre- and postcontrast CTs and the dose distributions based on both were compared. RESULTS On average, the distance of centroids of the populated duodenum contours on precontrast CT differed by 6.0 ± 4.0 mm from those on postcontrast CTs. The dose distributions on the precontrast CT and VNC were almost identical. The PTV mean and maximum doses differed by 0.1% and 0.2% between the two plans, respectively. CONCLUSION The VNC derived from DECT can be used to replace the conventional precontrast CT scan for RT planning, eliminating the need for an additional precontrast CT scan and eliminating the registration errors. Thus, VNC can become an important asset to the future of RT.
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Affiliation(s)
- George Noid
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Diane Schott
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Eric Paulson
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Justin Zhu
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Jainil Shah
- Siemens Medical Solutions USA, Inc., Malvern, PA, USA
| | - X Allen Li
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, USA
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12
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Parakh A, Lennartz S, An C, Rajiah P, Yeh BM, Simeone FJ, Sahani DV, Kambadakone AR. Dual-Energy CT Images: Pearls and Pitfalls. Radiographics 2021; 41:98-119. [PMID: 33411614 PMCID: PMC7853765 DOI: 10.1148/rg.2021200102] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 07/10/2020] [Accepted: 07/16/2020] [Indexed: 01/10/2023]
Abstract
Dual-energy CT (DECT) is a tremendous innovation in CT technology that allows creation of numerous imaging datasets by enabling discrete acquisitions at more than one energy level. The wide range of images generated from a single DECT acquisition provides several benefits such as improved lesion detection and characterization, superior determination of material composition, reduction in the dose of iodine, and more robust quantification. Technological advances and the proliferation of various processing methods have led to the availability of diverse vendor-based DECT approaches, each with a different acquisition and image reconstruction process. The images generated from various DECT scanners differ from those from conventional single-energy CT because of differences in their acquisition techniques, material decomposition methods, image reconstruction algorithms, and postprocessing methods. DECT images such as virtual monochromatic images, material density images, and virtual unenhanced images have different imaging appearances, texture features, and quantitative capabilities. This heterogeneity creates challenges in their routine interpretation and has certain associated pitfalls. Some artifacts such as residual iodine on virtual unenhanced images and an appearance of pseudopneumatosis in a gas-distended bowel loop on material-density iodine images are specific to DECT, while others such as pseudoenhancement seen on virtual monochromatic images are also observed at single-energy CT. Recognizing the potential pitfalls associated with DECT is necessary for appropriate and accurate interpretation of the results of this increasingly important imaging tool. Online supplemental material is available for this article. ©RSNA, 2021.
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Affiliation(s)
- Anushri Parakh
- From the Department of Radiology, Massachusetts General Hospital, 55 Fruit St, White 270, Boston, MA 02114 (A.P., S.L., F.J.S., A.R.K.); Department of Radiology and Biomedical Imaging, University of California–San Francisco, San Francisco, Calif (C.A., B.M.Y.); Department of Radiology, Mayo Clinic, Rochester, Minn (P.R.); Department of Radiology, University of Washington, Seattle, Wash (D.V.S.); and Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany (S.L.)
| | - Simon Lennartz
- From the Department of Radiology, Massachusetts General Hospital, 55 Fruit St, White 270, Boston, MA 02114 (A.P., S.L., F.J.S., A.R.K.); Department of Radiology and Biomedical Imaging, University of California–San Francisco, San Francisco, Calif (C.A., B.M.Y.); Department of Radiology, Mayo Clinic, Rochester, Minn (P.R.); Department of Radiology, University of Washington, Seattle, Wash (D.V.S.); and Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany (S.L.)
| | - Chansik An
- From the Department of Radiology, Massachusetts General Hospital, 55 Fruit St, White 270, Boston, MA 02114 (A.P., S.L., F.J.S., A.R.K.); Department of Radiology and Biomedical Imaging, University of California–San Francisco, San Francisco, Calif (C.A., B.M.Y.); Department of Radiology, Mayo Clinic, Rochester, Minn (P.R.); Department of Radiology, University of Washington, Seattle, Wash (D.V.S.); and Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany (S.L.)
| | - Prabhakar Rajiah
- From the Department of Radiology, Massachusetts General Hospital, 55 Fruit St, White 270, Boston, MA 02114 (A.P., S.L., F.J.S., A.R.K.); Department of Radiology and Biomedical Imaging, University of California–San Francisco, San Francisco, Calif (C.A., B.M.Y.); Department of Radiology, Mayo Clinic, Rochester, Minn (P.R.); Department of Radiology, University of Washington, Seattle, Wash (D.V.S.); and Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany (S.L.)
| | - Benjamin M. Yeh
- From the Department of Radiology, Massachusetts General Hospital, 55 Fruit St, White 270, Boston, MA 02114 (A.P., S.L., F.J.S., A.R.K.); Department of Radiology and Biomedical Imaging, University of California–San Francisco, San Francisco, Calif (C.A., B.M.Y.); Department of Radiology, Mayo Clinic, Rochester, Minn (P.R.); Department of Radiology, University of Washington, Seattle, Wash (D.V.S.); and Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany (S.L.)
| | - Frank J. Simeone
- From the Department of Radiology, Massachusetts General Hospital, 55 Fruit St, White 270, Boston, MA 02114 (A.P., S.L., F.J.S., A.R.K.); Department of Radiology and Biomedical Imaging, University of California–San Francisco, San Francisco, Calif (C.A., B.M.Y.); Department of Radiology, Mayo Clinic, Rochester, Minn (P.R.); Department of Radiology, University of Washington, Seattle, Wash (D.V.S.); and Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany (S.L.)
| | - Dushyant V. Sahani
- From the Department of Radiology, Massachusetts General Hospital, 55 Fruit St, White 270, Boston, MA 02114 (A.P., S.L., F.J.S., A.R.K.); Department of Radiology and Biomedical Imaging, University of California–San Francisco, San Francisco, Calif (C.A., B.M.Y.); Department of Radiology, Mayo Clinic, Rochester, Minn (P.R.); Department of Radiology, University of Washington, Seattle, Wash (D.V.S.); and Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany (S.L.)
| | - Avinash R. Kambadakone
- From the Department of Radiology, Massachusetts General Hospital, 55 Fruit St, White 270, Boston, MA 02114 (A.P., S.L., F.J.S., A.R.K.); Department of Radiology and Biomedical Imaging, University of California–San Francisco, San Francisco, Calif (C.A., B.M.Y.); Department of Radiology, Mayo Clinic, Rochester, Minn (P.R.); Department of Radiology, University of Washington, Seattle, Wash (D.V.S.); and Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany (S.L.)
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13
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Quantitative accuracy of virtual non-contrast images derived from spectral detector computed tomography: an abdominal phantom study. Sci Rep 2020; 10:21575. [PMID: 33299004 PMCID: PMC7725817 DOI: 10.1038/s41598-020-78518-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 11/17/2020] [Indexed: 11/25/2022] Open
Abstract
Dual-energy CT allows for the reconstruction of virtual non-contrast (VNC) images. VNC images have the potential to replace true non-contrast scans in various clinical applications. This study investigated the quantitative accuracy of VNC attenuation images considering different parameters for acquisition and reconstruction. An abdomen phantom with 7 different tissue types (different combinations of 3 base materials and 5 iodine concentrations) was scanned using a spectral detector CT (SDCT). Different phantom sizes (S, M, L), volume computed tomography dose indices (CTDIvol 10, 15, 20 mGy), kernel settings (soft, standard, sharp), and denoising levels (low, medium, high) were tested. Conventional and VNC images were reconstructed and analyzed based on regions of interest (ROI). Mean and standard deviation were recorded and differences in attenuation between corresponding base materials and VNC was calculated (VNCerror). Statistic analysis included ANOVA, Wilcoxon test and multivariate regression analysis. Overall, the VNCerror was − 1.4 ± 6.1 HU. While radiation dose, kernel setting, and denoising level did not influence VNCerror significantly, phantom size, iodine content and base material had a significant effect (e.g. S vs. M: − 1.2 ± 4.9 HU vs. − 2.1 ± 6.0 HU; 0.0 mg/ml vs. 5.0 mg/ml: − 4.0 ± 3.5 HU vs. 5.1 ± 5.0 HU and 35-HU-base vs. 54-HU-base: − 3.5 ± 4.4 HU vs. 0.7 ± 6.5; all p ≤ 0.05). The overall accuracy of VNC images from SDCT is high and independent from dose, kernel, and denoising settings; however, shows a dependency on patient size, base material, and iodine content; particularly the latter results in small, yet, noticeable differences in VNC attenuation.
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14
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Laukamp KR, Ho V, Obmann VC, Herrmann K, Gupta A, Borggrefe J, Lennartz S, Große Hokamp N, Ramaiya N. Virtual non-contrast for evaluation of liver parenchyma and vessels: results from 25 patients using multi-phase spectral-detector CT. Acta Radiol 2020; 61:1143-1152. [PMID: 31856581 DOI: 10.1177/0284185119893094] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND In abdominal imaging, contrast-enhanced computed tomography (CT) examinations are most commonly applied; however, unenhanced examinations are still needed for several clinical questions but require additional scanning and radiation exposure. PURPOSE To evaluate accuracy of virtual non-contrast (VNC) from arterial and venous phase spectral-detector CT (SDCT) scans compared to true-unenhanced (TNC) images for the evaluation of liver parenchyma and vessels. MATERIAL AND METHODS A total of 25 patients undergoing triphasic SDCT examinations were included. VNC was reconstructed from arterial and venous phases and compared to TNC images. Quantitative image analysis was performed by region of interest (ROI)-based assessment of mean and SD of attenuation (HU) in each liver segment, spleen, portal vein, common hepatic artery, and abdominal aorta. Subjectively, iodine subtraction and diagnostic assessment were rated on 5-point Likert scales. RESULTS Attenuation and image noise measured in the liver from VNC were not significantly different from TNC (TNC: 54.6 ± 10.8 HU, VNC arterial phase: 55.7 ± 10.8 HU; VNC venous phase: 58.3 ± 10.0 HU; P > 0.05). VNC also showed accurate results regarding attenuation and image noise for spleen, portal vein, and abdominal aorta. Only iodine subtraction in the common hepatic artery in the arterial phase was insufficient which was confirmed by the subjective reading. Apart from that, subjective reading showed accurate iodine subtraction and comparable diagnostic assessment. CONCLUSION VNC from the arterial and venous phases were very similar to TNC yielding mostly negligible differences in attenuation, image noise, and diagnostic utility. Inadequate iodine subtraction occurred in hepatic arteries in the arterial phase.
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Affiliation(s)
- Kai Roman Laukamp
- University Hospitals Cleveland Medical Center, Department of Radiology, Cleveland, OH, USA
- Case Western Reserve University, Department of Radiology, Cleveland, OH, USA
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Vivian Ho
- University Hospitals Cleveland Medical Center, Department of Radiology, Cleveland, OH, USA
- Case Western Reserve University, Department of Radiology, Cleveland, OH, USA
| | - Verena Carola Obmann
- University Hospitals Cleveland Medical Center, Department of Radiology, Cleveland, OH, USA
- Case Western Reserve University, Department of Radiology, Cleveland, OH, USA
- Institute of Diagnostic, Interventional and Pediatric Radiology, University Hospital Bern, Bern, Switzerland
| | - Karin Herrmann
- University Hospitals Cleveland Medical Center, Department of Radiology, Cleveland, OH, USA
- Case Western Reserve University, Department of Radiology, Cleveland, OH, USA
| | - Amit Gupta
- University Hospitals Cleveland Medical Center, Department of Radiology, Cleveland, OH, USA
- Case Western Reserve University, Department of Radiology, Cleveland, OH, USA
| | - Jan Borggrefe
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Simon Lennartz
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Nils Große Hokamp
- University Hospitals Cleveland Medical Center, Department of Radiology, Cleveland, OH, USA
- Case Western Reserve University, Department of Radiology, Cleveland, OH, USA
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Nikhil Ramaiya
- University Hospitals Cleveland Medical Center, Department of Radiology, Cleveland, OH, USA
- Case Western Reserve University, Department of Radiology, Cleveland, OH, USA
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Lehti L, Söderberg M, Höglund P, Wassélius J. Comparing Arterial- and Venous-Phase Acquisition for Optimization of Virtual Noncontrast Images From Dual-Energy Computed Tomography Angiography. J Comput Assist Tomogr 2019; 43:770-774. [PMID: 31425308 PMCID: PMC6752687 DOI: 10.1097/rct.0000000000000903] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Follow-up with computed tomographic angiography is recommended after endovascular aneurysm repair, exposing patients to significant levels of radiation and iodine contrast medium. Dual-energy computed tomography allows virtual noncontrast (VNC) images to be reconstructed from contrast-enhanced images using a software algorithm. If the VNC images are a good-enough approximation of true noncontrast (TNC) images, a reduction in radiation dose can be ensured through omitting a TNC scan.
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Affiliation(s)
- Leena Lehti
- From the Department of Clinical Sciences, Lund University, Lund.,Vascular Center, Skåne University Hospital
| | - Marcus Söderberg
- Department of Translational Medicine, Medical Radiation Physics, Lund University.,Radiation Physics, Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Malmö
| | - Peter Höglund
- From the Department of Clinical Sciences, Lund University, Lund
| | - Johan Wassélius
- From the Department of Clinical Sciences, Lund University, Lund.,Department of Neuroradiology, Skåne University Hospital, Lund, Sweden
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16
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Rotzinger DC, Si-Mohamed SA, Shapira N, Douek PC, Meuli RA, Boussel L. "Dark-blood" dual-energy computed tomography angiography for thoracic aortic wall imaging. Eur Radiol 2019; 30:425-431. [PMID: 31332557 DOI: 10.1007/s00330-019-06336-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 05/23/2019] [Accepted: 06/21/2019] [Indexed: 01/17/2023]
Abstract
OBJECTIVES To assess the capability of a newly developed material decomposition method from contrast-enhanced dual-energy CT images, aiming to better visualize the aortic wall and aortic intramural hematoma (IMH), compared with true non-contrast (TNC) CT. MATERIALS AND METHODS Twenty-two patients (11 women; mean age, 61 ± 20 years) with acute chest pain underwent 25 dual-layer non-contrast and contrast-enhanced CT. CT-angiography images were retrospectively processed using two-material decomposition analysis, where we defined the first material as the content of a region of interest placed in the ascending aorta for each patient, and the second material as water. Two independent radiologists assessed the images from the second material termed "dark-blood" images and the TNC images regarding contrast-to-noise ratio (CNR) between the wall and the lumen, diagnostic quality regarding the presence of aortic wall thickening, and the inner/outer vessel wall conspicuity. RESULTS Diagnostic quality scores in normal aortic segments were 0.9 ± 0.3 and 2.7 ± 0.6 (p < 0.001) and wall conspicuity scores were 0.7 ± 0.5 and 1.8 ± 0.3 (p < 0.001) on TNC and dark-blood images, respectively. In aortic segments with IMH, diagnostic quality scores were 1.7 ± 0.5 and 2.4 ± 0.6 (p < 0.001) and wall conspicuity scores were 0.7 ± 0.7 and 1.8 ± 0.3 (p < 0.001) on TNC and dark-blood images, respectively. In normal aortic segments, CNRs were 0.3 ± 0.2 and 2.8 ± 0.9 on TNC and dark-blood images, respectively (p < 0.001). In aortic segments with IMH, CNRs were 0.3 ± 0.2 and 4.0 ± 1.0 on TNC and dark-blood images, respectively (p < 0.001). CONCLUSIONS Compared with true non-contrast CT, dark-blood material decomposition maps enhance quantitative and qualitative image quality for the assessment of normal aortic wall and IMH. KEY POINTS • Current dual-energy CT-angiography provides virtual non-contrast and bright-blood images. • Dark-blood images represent a new way to assess the vascular wall structure with dual-energy CT and can improve the lumen-to-wall contrast compared with true non-contrast CT. • This dual-energy CT material decomposition method is likely to improve contrast resolution in other applications as well, taking advantage of the high spatial resolution of CT.
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Affiliation(s)
- David C Rotzinger
- Department of Diagnostic and Interventional Radiology, Lausanne University Hospital (CHUV), Rue du Bugnon 46, 1011, Lausanne, Switzerland. .,Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), Lausanne, Switzerland.
| | - Salim A Si-Mohamed
- Radiology Department, Hospices Civils de Lyon (HCL), Lyon, France.,University Claude Bernard Lyon 1, CREATIS, CNRS UMR 5220, INSERM U1206, INSA-Lyon, Lyon, France
| | - Nadav Shapira
- CT/AMI Research and Development, Philips Medical Systems, Haifa, Israel
| | - Philippe C Douek
- Radiology Department, Hospices Civils de Lyon (HCL), Lyon, France.,University Claude Bernard Lyon 1, CREATIS, CNRS UMR 5220, INSERM U1206, INSA-Lyon, Lyon, France
| | - Reto A Meuli
- Department of Diagnostic and Interventional Radiology, Lausanne University Hospital (CHUV), Rue du Bugnon 46, 1011, Lausanne, Switzerland.,Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), Lausanne, Switzerland
| | - Loïc Boussel
- Radiology Department, Hospices Civils de Lyon (HCL), Lyon, France.,University Claude Bernard Lyon 1, CREATIS, CNRS UMR 5220, INSERM U1206, INSA-Lyon, Lyon, France
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Si-Mohamed S, Dupuis N, Tatard-Leitman V, Rotzinger D, Boccalini S, Dion M, Vlassenbroek A, Coulon P, Yagil Y, Shapira N, Douek P, Boussel L. Virtual versus true non-contrast dual-energy CT imaging for the diagnosis of aortic intramural hematoma. Eur Radiol 2019; 29:6762-6771. [PMID: 31264015 DOI: 10.1007/s00330-019-06322-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 05/24/2019] [Accepted: 06/11/2019] [Indexed: 12/23/2022]
Abstract
PURPOSE To assess whether virtual non-contrast (VNC) images derived from contrast dual-layer dual-energy computed tomography (DL-DECT) images could replace true non-contrast (TNC) images for aortic intramural hematoma (IMH) diagnosis in acute aortic syndrome (AAS) imaging protocols by performing quantitative as well as qualitative phantom and clinical studies. MATERIALS AND METHODS Patients with confirmed IMH were included retrospectively in two centers. For in vitro imaging, a custom-made phantom of IMH was placed in a semi-anthropomorphic thorax phantom (QRM GmbH) and imaged on a DL-DECT at 120 kVp under various conditions of patient size, radiation exposure, and reconstruction modes. For in vivo imaging, 21 patients (70 ± 13 years) who underwent AAS imaging protocols at 120 kVp were included. In both studies, contrast-to-noise ratio (CNR) between hematoma and lumen was compared using a paired t test. Diagnostic confidence (1 = non-diagnostic, 4 = exemplary) for VNC and TNC images was rated by two radiologists and compared. Effective radiation doses for each acquisition were calculated. RESULTS In both the phantom and clinical studies, we observed that the CNRs were similar between the VNC and TNC images. Moreover, both methods allowed differentiating the hyper-attenuation within the hematoma from the blood. Finally, we obtained equivalent high diagnostic confidence with both VNC and TNC images (VNC = 3.2 ± 0.7, TNC = 3.1 ± 0.7; p = 0.3). Finally, by suppressing TNC acquisition and using VNC, the mean effective dose reduction would be 40%. CONCLUSION DL-DECT offers similar performances with VNC and TNC images for IMH diagnosis without compromise in diagnostic image quality. KEY POINTS • Dual-layer dual-energy CT enables virtual non-contrast imaging from a contrast-enhanced acquisition. • Virtual non-contrast imaging with dual-layer dual-energy CT reduces the number of acquisitions and radiation exposure in acute aortic syndrome imaging protocol. • Dual-layer dual-energy CT has the potential to become a suitable imaging tool for acute aortic syndrome.
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Affiliation(s)
- Salim Si-Mohamed
- Univ Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, F-69621, Lyon, France.
- Radiology Department, Hospices Civils de Lyon, CHU Louis Pradel, 59 Boulevard Pinel, 69500, Bron, France.
| | - Nicolas Dupuis
- Univ Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, F-69621, Lyon, France
- Radiology Department, Hospices Civils de Lyon, CHU Louis Pradel, 59 Boulevard Pinel, 69500, Bron, France
- Anatomy Lab, Rockefeller Faculty, Lyon Est, Lyon, France
| | - Valérie Tatard-Leitman
- Univ Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, F-69621, Lyon, France
| | - David Rotzinger
- Department of Diagnostic and Interventional Radiology, Lausanne University Hospital , Lausanne, Switzerland
| | - Sara Boccalini
- Radiology Department, Hospices Civils de Lyon, CHU Louis Pradel, 59 Boulevard Pinel, 69500, Bron, France
| | - Matthias Dion
- Univ Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, F-69621, Lyon, France
- Radiology Department, Hospices Civils de Lyon, CHU Louis Pradel, 59 Boulevard Pinel, 69500, Bron, France
- Anatomy Lab, Rockefeller Faculty, Lyon Est, Lyon, France
| | | | | | - Yoad Yagil
- Global Advanced Technologies, CT, Philips, Haifa, Israel
| | - Nadav Shapira
- Global Advanced Technologies, CT, Philips, Haifa, Israel
| | - Philippe Douek
- Univ Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, F-69621, Lyon, France
- Radiology Department, Hospices Civils de Lyon, CHU Louis Pradel, 59 Boulevard Pinel, 69500, Bron, France
| | - Loic Boussel
- Univ Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, F-69621, Lyon, France
- Radiology Department, Hospices Civils de Lyon, CHU Louis Pradel, 59 Boulevard Pinel, 69500, Bron, France
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