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Otgonbaatar C, Kim H, Jeon PH, Jeon SH, Cha SJ, Ryu JK, Jung WB, Shim H, Ko SM, Kim JW. A preliminary study of super-resolution deep learning reconstruction with cardiac option for evaluation of endovascular-treated intracranial aneurysms. Br J Radiol 2024; 97:1492-1500. [PMID: 38917414 PMCID: PMC11256923 DOI: 10.1093/bjr/tqae117] [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: 12/26/2023] [Revised: 04/22/2024] [Accepted: 06/06/2024] [Indexed: 06/27/2024] Open
Abstract
OBJECTIVES To investigate the usefulness of super-resolution deep learning reconstruction (SR-DLR) with cardiac option in the assessment of image quality in patients with stent-assisted coil embolization, coil embolization, and flow-diverting stent placement compared with other image reconstructions. METHODS This single-centre retrospective study included 50 patients (mean age, 59 years; range, 44-81 years; 13 men) who were treated with stent-assisted coil embolization, coil embolization, and flow-diverting stent placement between January and July 2023. The images were reconstructed using filtered back projection (FBP), hybrid iterative reconstruction (IR), and SR-DLR. The objective image analysis included image noise in the Hounsfield unit (HU), signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and full width at half maximum (FWHM). Subjectively, two radiologists evaluated the overall image quality for the visualization of the flow-diverting stent, coil, and stent. RESULTS The image noise in HU in SR-DLR was 6.99 ± 1.49, which was significantly lower than that in images reconstructed with FBP (12.32 ± 3.01) and hybrid IR (8.63 ± 2.12) (P < .001). Both the mean SNR and CNR were significantly higher in SR-DLR than in FBP and hybrid IR (P < .001 and P < .001). The FWHMs for the stent (P < .004), flow-diverting stent (P < .001), and coil (P < .001) were significantly lower in SR-DLR than in FBP and hybrid IR. The subjective visual scores were significantly higher in SR-DLR than in other image reconstructions (P < .001). CONCLUSIONS SR-DLR with cardiac option is useful for follow-up imaging in stent-assisted coil embolization and flow-diverting stent placement in terms of lower image noise, higher SNR and CNR, superior subjective image analysis, and less blooming artifact than other image reconstructions. ADVANCES IN KNOWLEDGE SR-DLR with cardiac option allows better visualization of the peripheral and smaller cerebral arteries. SR-DLR with cardiac option can be beneficial for CT imaging of stent-assisted coil embolization and flow-diverting stent.
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Affiliation(s)
- Chuluunbaatar Otgonbaatar
- Department of Radiology, College of Medicine, Seoul National University, Seoul, 03080, Republic of Korea
- Medical Imaging AI Research Center, Canon Medical Systems Korea, Seoul, 06173, Republic of Korea
| | - Hyunjung Kim
- Department of Radiology, Wonju Severance Christian Hospital, Wonju College of Medicine, Yonsei University of Korea, Wonju 26426, Republic of Korea
| | - Pil-Hyun Jeon
- Department of Radiology, Wonju Severance Christian Hospital, Wonju College of Medicine, Yonsei University of Korea, Wonju 26426, Republic of Korea
| | - Sang-Hyun Jeon
- Department of Radiology, Wonju Severance Christian Hospital, Wonju College of Medicine, Yonsei University of Korea, Wonju 26426, Republic of Korea
| | - Sung-Jin Cha
- Department of Radiology, Wonju Severance Christian Hospital, Wonju College of Medicine, Yonsei University of Korea, Wonju 26426, Republic of Korea
| | - Jae-Kyun Ryu
- Medical Imaging AI Research Center, Canon Medical Systems Korea, Seoul, 06173, Republic of Korea
| | - Won Beom Jung
- Korea Brain Research Institute (KBRI), Daegu, 41062, Republic of Korea
| | - Hackjoon Shim
- Medical Imaging AI Research Center, Canon Medical Systems Korea, Seoul, 06173, Republic of Korea
- ConnectAI Research Center, Yonsei University College of Medicine, Seoul, 03772, Republic of Korea
| | - Sung Min Ko
- Department of Radiology, Wonju Severance Christian Hospital, Wonju College of Medicine, Yonsei University of Korea, Wonju 26426, Republic of Korea
| | - Jin Woo Kim
- Department of Radiology, Wonju Severance Christian Hospital, Wonju College of Medicine, Yonsei University of Korea, Wonju 26426, Republic of Korea
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Lennartz S, Zopfs D, Große Hokamp N. Dual-energy CT revisited: a focused review of clinical use cases. ROFO-FORTSCHR RONTG 2024; 196:794-806. [PMID: 38176436 DOI: 10.1055/a-2203-2945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2024]
Affiliation(s)
- Simon Lennartz
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - David Zopfs
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Nils Große Hokamp
- Institute for Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
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Watanabe S, Urikura A, Ohashi K, Kitera N, Tsuchiya T, Kasai H, Kawai T, Hiwatashi A. Artifact reduction in low and ultra-low dose chest computed tomography for patients with pacemaker: A phantom study. Radiography (Lond) 2024; 30:770-775. [PMID: 38460224 DOI: 10.1016/j.radi.2024.02.019] [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: 11/21/2023] [Revised: 02/06/2024] [Accepted: 02/23/2024] [Indexed: 03/11/2024]
Abstract
INTRODUCTION Implanted pacemakers (PM) would decrease the detection of lung nodules in chest computed tomography (CT) due to the metal artifact. This study aimed to explore the computer-aided diagnosis (CAD) detectability of pulmonary nodules for the patients implanted with PMs in low- and ultra-low-dose chest CT screening. METHODS Four different sizes of artificial nodules were placed in an anthropomorphic chest phantom with two alternative diameters utilized. A commercially available PM was placed on the surface of the left chest wall of the phantom. The image acquisitions were performed with 120 kV and 150 kV with a dedicated selective photon shield made of tin filter (Sn150 kV) at low- and ultra-low- radiation doses (1.0 and 0.5 mGy of volume CT dose index), and reconstructed with and without Iterative Metal Artifact Reduction (iMAR, Siemens Healthineers, Erlangen, Germany). The relative artifact index (AIr) was calculated as an index of metal artifacts, and the nodule detectability was evaluated with a CAD system. RESULTS Sn150 kV reduced AIr in all acquisitions when comparing 120 kV and Sn150 kV. Although PM reduced the detectability of nodules, Sn150 kV showed higher detectability compared to 120 kV. The use of iMAR showed inconsistent results in nodule detectability. CONCLUSION Sn150 kV reduced PM-induced metal artifacts and improved nodule detectability with CAD compared to 120 kV acquisition in many conditions including low and ultra-low doses and large phantoms, but iMAR did not improve the detectability. IMPLICATIONS FOR PRACTICE Based on the results of the current phantom study, low and ultra-low dose with Sn150 kV acquisition reduced PM-induced metal artifacts and improved nodule detectability.
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Affiliation(s)
- S Watanabe
- Department of Radiology, Nagoya City University Hospital, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi 467-0001, Japan.
| | - A Urikura
- Department of Radiological Technology, Radiological Diagnosis, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045, Japan.
| | - K Ohashi
- Department of Radiology, Nagoya City University Midori Municipal Hospital, 1-77 Shiomigaoka, Midori-ku, Nagoya, Aichi, 458-0037, Japan; Department of Radiology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi 467-0001, Japan.
| | - N Kitera
- Department of Radiology, Nagoya City University Hospital, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi 467-0001, Japan.
| | - T Tsuchiya
- Department of Radiology, Nagoya City University Hospital, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi 467-0001, Japan.
| | - H Kasai
- Department of Radiology, Nagoya City University Hospital, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi 467-0001, Japan.
| | - T Kawai
- Department of Radiology, Nagoya City University Midori Municipal Hospital, 1-77 Shiomigaoka, Midori-ku, Nagoya, Aichi, 458-0037, Japan; Department of Radiology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi 467-0001, Japan.
| | - A Hiwatashi
- Department of Radiology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi 467-0001, Japan.
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Goertz L, Al-Sewaidi Y, Habib M, Zopfs D, Reichardt B, Ranft A, Kabbasch C. State-of-the-art mobile head CT scanner delivers nearly the same image quality as a conventional stationary CT scanner. Sci Rep 2024; 14:6393. [PMID: 38493258 PMCID: PMC10944493 DOI: 10.1038/s41598-024-56089-z] [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: 12/20/2023] [Accepted: 03/01/2024] [Indexed: 03/18/2024] Open
Abstract
The use of mobile head CT scanners in the neurointensive care unit (NICU) saves time for patients and NICU staff and can reduce transport-related mishaps, but the reduced image quality of previous mobile scanners has prevented their widespread clinical use. This study compares the image quality of SOMATOM On.Site (Siemens Healthineers, Erlangen, Germany), a state-of-the-art mobile head CT scanner, and a conventional 64-slice stationary CT scanner. The study included 40 patients who underwent head scans with both mobile and stationary scanners. Gray and white matter signal and noise were measured at predefined locations on axial slices, and signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) were calculated. Artifacts below the cranial calvaria and in the posterior fossa were also measured. In addition, image quality was subjectively assessed by two radiologists in terms of corticomedullary differentiation, subcalvarial space, skull artifacts, and image noise. Quantitative measurements showed significantly higher image quality of the stationary CT scanner in terms of noise, SNR and CNR of gray and white matter. Artifacts measured in the posterior fossa were higher with the mobile CT scanner, but subcalvarial artifacts were comparable. Subjective image quality was rated similarly by two radiologists for both scanners in all domains except image noise, which was better for stationary CT scans. The image quality of the SOMATOM On.Site for brain scans is inferior to that of the conventional stationary scanner, but appears to be adequate for daily use in a clinical setting based on subjective ratings.
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Affiliation(s)
- Lukas Goertz
- Department of Radiology and Neuroradiology, Faculty of Medicine and University Hospital, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany.
| | - Yosef Al-Sewaidi
- Department of Interventional Radiology and Neuroradiology, Klinikum Hochsauerland, Arnsberg, Germany
| | - Mahmoud Habib
- Department of Interventional Radiology and Neuroradiology, Klinikum Hochsauerland, Arnsberg, Germany
| | - David Zopfs
- Department of Radiology and Neuroradiology, Faculty of Medicine and University Hospital, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany
| | - Benjamin Reichardt
- Department of Interventional Radiology and Neuroradiology, Klinikum Hochsauerland, Arnsberg, Germany
| | - Alexander Ranft
- Department of Interventional Radiology and Neuroradiology, Klinikum Hochsauerland, Arnsberg, Germany
| | - Christoph Kabbasch
- Department of Radiology and Neuroradiology, Faculty of Medicine and University Hospital, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany
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Zhou Y, Lei L, Wang Z, Cao W, Qin M, Dong S, Dang J, Zhou Z. Utility of spectral CT with orthopedic metal artifact reduction algorithms for 125I seeds implantation in mediastinal and hepatic tumors. Quant Imaging Med Surg 2024; 14:698-710. [PMID: 38223075 PMCID: PMC10784080 DOI: 10.21037/qims-23-843] [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: 06/09/2023] [Accepted: 11/08/2023] [Indexed: 01/16/2024]
Abstract
Background Virtual monochromatic image (VMI) combined with orthopedic metal artifact reduction algorithms (VMI + O-MAR) can effectively reduce artifacts caused by metal implants of different types. Nevertheless, so far, no study has systematically evaluated the efficacy of VMI + O-MAR in reducing various types of metal artifacts induced by 125I seeds. The aim of this study was to assess the effectiveness of combining spectral computed tomography (CT) images with O-MAR in reducing metal artifacts and improving the image quality affected by artifacts in patients after 125I radioactive seeds implantation (RSI). Methods A total of 45 patients who underwent dual-layer detector spectral CT (DLCT; IQon, Philips Healthcare) scanning of mediastinal and hepatic tumors after 125I RSI were retrospectively included. Spectral data were reconstructed into conventional image (CI), VMI, CI combined with O-MAR (CI + O-MAR), and VMI + O-MAR to evaluate the de-artifact effect and image quality improvement. Objective indicators included signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and artifact index (AI) of lesions affected by artifacts. Subjective indicators included assessment of overcorrected artifacts and new artifacts, different morphology of artifacts, and overall image quality. Results In artifact-affected lesion areas, SNR and CNR in the CI/VMI + O-MAR groups were better than those in CI groups (all P values <0.05). The AI showed a downward trend as VMI keV increased (all P values <0.001). The AI values of the CI/VMI (50-150 keV) group were all higher than the groups of CI/VMI + O-MAR (50-150 keV) (P<0.001). Overcorrection artifacts and new artifacts were concentrated in the VMI50/70 keV groups. In the evaluation of artifact morphology, as the VMI keV increased, the number of near-field banding artifacts in hyperdense artifacts gradually decreased, whereas the number of minimal or no artifacts increased, and the total number of hyperdense artifacts were decreased. The diagnostic and image quality scores of hyperdense artifacts were higher than those of hypodense artifacts as VMI keV increased. Conclusions High VMI level combined with O-MAR substantially improve objective and subjective image quality, lesion display ability, and diagnostic confidence of CT follow-up after 125I RSI, especially at the VMI + O-MAR 150 keV level.
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Affiliation(s)
- Yuhan Zhou
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Limin Lei
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Zhihao Wang
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Weimeng Cao
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Minghui Qin
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Shushan Dong
- Department of Clinical Science, Philips Healthcare, Beijing, China
| | - Jinjin Dang
- Department of Clinical Science, Philips Healthcare, Beijing, China
| | - Zhigang Zhou
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
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Selles M, van Osch JAC, Maas M, Boomsma MF, Wellenberg RHH. Advances in metal artifact reduction in CT images: A review of traditional and novel metal artifact reduction techniques. Eur J Radiol 2024; 170:111276. [PMID: 38142571 DOI: 10.1016/j.ejrad.2023.111276] [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: 11/02/2023] [Revised: 12/14/2023] [Accepted: 12/18/2023] [Indexed: 12/26/2023]
Abstract
Metal artifacts degrade CT image quality, hampering clinical assessment. Numerous metal artifact reduction methods are available to improve the image quality of CT images with metal implants. In this review, an overview of traditional methods is provided including the modification of acquisition and reconstruction parameters, projection-based metal artifact reduction techniques (MAR), dual energy CT (DECT) and the combination of these techniques. Furthermore, the additional value and challenges of novel metal artifact reduction techniques that have been introduced over the past years are discussed such as photon counting CT (PCCT) and deep learning based metal artifact reduction techniques.
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Affiliation(s)
- Mark Selles
- Department of Radiology, Isala, 8025 AB Zwolle, the Netherlands; Department of Radiology and Nuclear Medicine, Amsterdam University Medical Centre, 1105 AZ Amsterdam, the Netherlands; Amsterdam Movement Sciences, 1081 BT Amsterdam, the Netherlands.
| | | | - Mario Maas
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Centre, 1105 AZ Amsterdam, the Netherlands; Amsterdam Movement Sciences, 1081 BT Amsterdam, the Netherlands
| | | | - Ruud H H Wellenberg
- Department of Radiology and Nuclear Medicine, Amsterdam University Medical Centre, 1105 AZ Amsterdam, the Netherlands; Amsterdam Movement Sciences, 1081 BT Amsterdam, the Netherlands
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Li Z, Lei P, Hua Q, Zhou L, Song P, Gao L, Zhang S, Cai Q. Surgical Clipping of Intracranial Aneurysms Using a Transcranial Neuroendoscopic Approach. Brain Sci 2023; 13:1544. [PMID: 38002504 PMCID: PMC10669543 DOI: 10.3390/brainsci13111544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 10/26/2023] [Accepted: 11/01/2023] [Indexed: 11/26/2023] Open
Abstract
OBJECTIVE This retrospective study was performed to evaluate the feasibility and safety of surgically clipping intracranial aneurysms using a transcranial neuroendoscopic approach. METHODS A total of 229 patients with cerebral aneurysms were included in our study, all of whom were treated with clamping surgery at Wuhan University People's Hospital. They were divided into neuroendoscopic and microscopic groups, according to whether or not neuroendoscopy was used for the clamping surgery. We statistically analyzed the patients' baseline data, surgical outcomes, and complications, which were then evaluated to assess the treatment effect. RESULTS The baseline characteristics were not statistically significant, except for gender, for which the proportions of female patients in the two groups were 69 (56.1%) and 46 (43.4%). There were no patients with incomplete aneurysm clamping or parent vessel occlusion in the neuroendoscopic group, and there were 4 (3.8%) and 2 (1.9%) in the microscopic group, respectively; however, there was no statistically significant difference in the comparison of the two groups. The mean operative times of the two groups were 181 min and 154 min, respectively, and were statistically different. However, the mRS scores of the two groups showed no significant difference in patient prognosis. The differences in complications (including limb hemiplegia, hydrocephalus, vision loss, and intracranial infection) were not statistically significant, except for cerebral ischemia, for which the proportions of patients in the two groups were 8 (6.5%) and 16 (15.1%). CONCLUSIONS Neuroendoscopy can provide clear visualization and multi-angle views during aneurysm clipping, which is helpful for ensuring adequate clipping and preventing complications.
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Affiliation(s)
- Zhiyang Li
- Department of Neurosurgery, Renmin Hospital of Wuhan University, Wuhan 430060, China; (Z.L.); (P.L.); (Q.H.); (L.Z.); (P.S.); (L.G.)
| | - Pan Lei
- Department of Neurosurgery, Renmin Hospital of Wuhan University, Wuhan 430060, China; (Z.L.); (P.L.); (Q.H.); (L.Z.); (P.S.); (L.G.)
| | - Qiuwei Hua
- Department of Neurosurgery, Renmin Hospital of Wuhan University, Wuhan 430060, China; (Z.L.); (P.L.); (Q.H.); (L.Z.); (P.S.); (L.G.)
| | - Long Zhou
- Department of Neurosurgery, Renmin Hospital of Wuhan University, Wuhan 430060, China; (Z.L.); (P.L.); (Q.H.); (L.Z.); (P.S.); (L.G.)
| | - Ping Song
- Department of Neurosurgery, Renmin Hospital of Wuhan University, Wuhan 430060, China; (Z.L.); (P.L.); (Q.H.); (L.Z.); (P.S.); (L.G.)
| | - Lun Gao
- Department of Neurosurgery, Renmin Hospital of Wuhan University, Wuhan 430060, China; (Z.L.); (P.L.); (Q.H.); (L.Z.); (P.S.); (L.G.)
| | - Silei Zhang
- Department of Neurosurgery, Xiantao First People’s Hospital Affiliated to Changjiang University, Xiantao 433000, China;
| | - Qiang Cai
- Department of Neurosurgery, Renmin Hospital of Wuhan University, Wuhan 430060, China; (Z.L.); (P.L.); (Q.H.); (L.Z.); (P.S.); (L.G.)
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Kazimierczak W, Nowak E, Kazimierczak N, Jankowski T, Jankowska A, Serafin Z. The value of metal artifact reduction and iterative algorithms in dual energy CT angiography in patients after complex endovascular aortic aneurysm repair. Heliyon 2023; 9:e20700. [PMID: 37876478 PMCID: PMC10590777 DOI: 10.1016/j.heliyon.2023.e20700] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 10/04/2023] [Accepted: 10/04/2023] [Indexed: 10/26/2023] Open
Abstract
Rationale and objectives Evaluation of the diagnostic value of linearly blended (LB) and virtual monoenergetic images (VMI) reconstruction techniques with and without metal artifacts reduction (MAR) and of adaptive statistical iterative reconstructions (ASIR) in the assessment of target vessels after branched/fenestrated endovascular aortic repair (f/brEVAR) procedures. Materials and methods CT scans of 28 patients were used in this study. Arterial phase of examination was obtained using a dual-energy fast-kVp switching scanner. CT numbers in the aorta, celiac trunk, superior mesenteric artery, and renal arteries were measured in the following reconstructions: LB, VMI 60 keV, VMI MAR 60 keV, VMI ASIR 60 % 60 keV. Contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) were calculated for each reconstruction. Luminal diameters (measurements at 2 levels of stent) and subjective image quality (5-point Likert scale) were assessed (2 readers, blinded to the type of reconstruction). Results The highest mean values of CNR and SNR in vascular structures were obtained in VMI MAR 60 keV (CNR 12.526 ± 2.46, SNR 17.398 ± 2.52), lower in VMI 60 keV (CNR 11.508 ± 2.01, SNR 16.524 ± 2.07) and VMI ASIR (CNR 11.086 ± 1.78, SNR 15.928 ± 1.82), and the lowest in LB (CNR 6.808 ± 0.79, SNR 11.492 ± 0.79) reconstructions. There were no statistically significant differences in the measurements of the stent width between reconstructions (p > 0.05). The highest subjective image quality was obtained in the ASIR VMI (4.25 ± 0.44) and the lowest in the MAR VMI (1.57 ± 0.5) reconstruction. Conclusion Despite obtaining the highest values of SNR and CNR in the MAR VMI reconstruction, the subjective diagnostic value was the lowest for this technique due to significant artifacts. The type of reconstruction did not significantly affect vessel diameter measurements (p > 0.05). Iterative reconstructions raised both objective and subjective image quality.
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Affiliation(s)
- Wojciech Kazimierczak
- Collegium Medicum, Nicolaus Copernicus University in Torun, Jagiellońska 13-15, 85-067, Bydgoszcz, Poland
- University Hospital No 1 in Bydgoszcz, Marii Skłodowskiej – Curie 9, 85-094, Bydgoszcz, Poland
- Kazimierczak Private Medical Practice, Dworcowa 13/u6a, 85-009, Bydgoszcz, Poland
| | - Ewa Nowak
- University Hospital No 1 in Bydgoszcz, Marii Skłodowskiej – Curie 9, 85-094, Bydgoszcz, Poland
| | - Natalia Kazimierczak
- Kazimierczak Private Medical Practice, Dworcowa 13/u6a, 85-009, Bydgoszcz, Poland
| | - Tomasz Jankowski
- Jankowscy Private Dental Practice, Czerwonego Krzyża 24, 68-200, Żary, Poland
| | - Agnieszka Jankowska
- Jankowscy Private Dental Practice, Czerwonego Krzyża 24, 68-200, Żary, Poland
| | - Zbigniew Serafin
- Collegium Medicum, Nicolaus Copernicus University in Torun, Jagiellońska 13-15, 85-067, Bydgoszcz, Poland
- University Hospital No 1 in Bydgoszcz, Marii Skłodowskiej – Curie 9, 85-094, Bydgoszcz, Poland
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Anhaus JA, Schmidt S, Killermann P, Mahnken A, Hofmann C. Iterative metal artifact reduction on a clinical photon counting system—technical possibilities and reconstruction selection for optimal results dependent on the metal scenario. Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac71f0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 05/20/2022] [Indexed: 11/12/2022]
Abstract
Abstract
Objective. To give an overview about technical possibilities for metal artifact reduction of the first clinical photon-counting CT system and assess optimal reconstruction settings in a phantom study, assessing monoenergetic imaging (VMI) and iterative metal artifact reduction (iMAR). Approach. Scans were performed with 120 kV and Sn140 kV on the first clinical photon-counting detector CT scanner. To quantify artifact reduction, anthropomorphic phantoms (hip, dental, spine, neuro) were assessed, in addition to a tissue characterization phantom (Gammex) to quantify the HU restoration accuracy, all with removable metal inserts. Each setup was reconstructed with and without dedicated iMAR, and VMIs were computed in 10 keV steps from 40 keV (60 keV at Sn140 kV) to 190 keV for all setups (ground truth and metal with and without iMAR). To find the optimal energy, pixel-wise errors were computed in relevant ROIs in water-equivalent tissue around the metal in each phantom setup. To assess HU restoration potential, measurements were performed in the Gammex phantom’s inserts. Main results. Large metal objects (hip head) or metal with high atomic numbers (dental and neuro) do not benefit from higher-energetic reconstructions. The hip shaft (large, low atomic number) comprises a lower base artifact level than the head, still without an energetic optimum. Within the spine (short penetration length, low atomic number) an energy optimum could be identified for both spectra (100 keV for 120 kV and 120 keV for Sn140 kV). The Gammex showed best HU restoration at 100 keV for 120 kV and at 110 keV for Sn140 kV. In all cases, additional iMAR reduced the base artifact level. Significance. This study shows that a novel photon-counting CT system has the capability to reduce metal artifacts in metal types with low atomic number and low penetration length by applying VMI. For all other metal types, additional iMAR is required to reduce artifacts.
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Michael AE, Boriesosdick J, Schoenbeck D, Lopez-Schmidt I, Kroeger JR, Moenninghoff C, Horstmeier S, Pennig L, Borggrefe J, Niehoff JH. Photon Counting CT Angiography of the Head and Neck: Image Quality Assessment of Polyenergetic and Virtual Monoenergetic Reconstructions. Diagnostics (Basel) 2022; 12:diagnostics12061306. [PMID: 35741116 PMCID: PMC9222087 DOI: 10.3390/diagnostics12061306] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 05/21/2022] [Accepted: 05/22/2022] [Indexed: 11/16/2022] Open
Abstract
Background: The purpose of the present study was the evaluation of the image quality of polyenergetic and monoenergetic reconstructions (PERs and MERs) of CT angiographies (CTAs) of the head and neck acquired with the novel photon counting CT (PCCT) method in clinical routine. Methods: Thirty-seven patients were enrolled in this retrospective study. Quantitative image parameters of the extracranial, intracranial and cerebral arteries were evaluated for the PER and MER (40–120 keV). Additionally, two radiologists rated the perceived image quality. Results: The mean CTDIvol used in the PCCT was 8.31 ± 1.19 mGy. The highest signal within the vessels was detected in the 40 keV MER, whereas the lowest noise was detected in the 115 keV MER. The most favorable contrast-to-noise-ratio (CNR) and signal-to-noise-ratio (SNR) were detected in the PER and low keV MER. In the qualitative image analysis, the PER was superior to the MER in all rated criteria. For MER, 60–65 keV was rated as best image quality. Conclusion: Overall, PCCT offers excellent image quality for CTAs of the head and neck. At the current state, the PER of the PCCT seems to be the most favorable reconstruction for diagnostic reporting.
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Affiliation(s)
- Arwed Elias Michael
- Department of Radiology, Neuroradiology and Nuclear Medicine, Johannes Wesling University Hospital, Ruhr University Bochum, 32429 Minden, Germany; (J.B.); (D.S.); (I.L.-S.); (J.R.K.); (C.M.); (S.H.); (J.B.); (J.H.N.)
- Correspondence: ; Tel.: +49-571-790-4601
| | - Jan Boriesosdick
- Department of Radiology, Neuroradiology and Nuclear Medicine, Johannes Wesling University Hospital, Ruhr University Bochum, 32429 Minden, Germany; (J.B.); (D.S.); (I.L.-S.); (J.R.K.); (C.M.); (S.H.); (J.B.); (J.H.N.)
| | - Denise Schoenbeck
- Department of Radiology, Neuroradiology and Nuclear Medicine, Johannes Wesling University Hospital, Ruhr University Bochum, 32429 Minden, Germany; (J.B.); (D.S.); (I.L.-S.); (J.R.K.); (C.M.); (S.H.); (J.B.); (J.H.N.)
| | - Ingo Lopez-Schmidt
- Department of Radiology, Neuroradiology and Nuclear Medicine, Johannes Wesling University Hospital, Ruhr University Bochum, 32429 Minden, Germany; (J.B.); (D.S.); (I.L.-S.); (J.R.K.); (C.M.); (S.H.); (J.B.); (J.H.N.)
| | - Jan Robert Kroeger
- Department of Radiology, Neuroradiology and Nuclear Medicine, Johannes Wesling University Hospital, Ruhr University Bochum, 32429 Minden, Germany; (J.B.); (D.S.); (I.L.-S.); (J.R.K.); (C.M.); (S.H.); (J.B.); (J.H.N.)
| | - Christoph Moenninghoff
- Department of Radiology, Neuroradiology and Nuclear Medicine, Johannes Wesling University Hospital, Ruhr University Bochum, 32429 Minden, Germany; (J.B.); (D.S.); (I.L.-S.); (J.R.K.); (C.M.); (S.H.); (J.B.); (J.H.N.)
| | - Sebastian Horstmeier
- Department of Radiology, Neuroradiology and Nuclear Medicine, Johannes Wesling University Hospital, Ruhr University Bochum, 32429 Minden, Germany; (J.B.); (D.S.); (I.L.-S.); (J.R.K.); (C.M.); (S.H.); (J.B.); (J.H.N.)
| | - Lenhard Pennig
- Institute of Diagnostic and Interventional Radiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50923 Cologne, Germany;
| | - Jan Borggrefe
- Department of Radiology, Neuroradiology and Nuclear Medicine, Johannes Wesling University Hospital, Ruhr University Bochum, 32429 Minden, Germany; (J.B.); (D.S.); (I.L.-S.); (J.R.K.); (C.M.); (S.H.); (J.B.); (J.H.N.)
| | - Julius Henning Niehoff
- Department of Radiology, Neuroradiology and Nuclear Medicine, Johannes Wesling University Hospital, Ruhr University Bochum, 32429 Minden, Germany; (J.B.); (D.S.); (I.L.-S.); (J.R.K.); (C.M.); (S.H.); (J.B.); (J.H.N.)
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Zheng H, Yang M, Jia Y, Zhang L, Sun X, Zhang Y, Nie Z, Wu H, Zhang X, Lei Z, Jing W. A Novel Subtraction Method to Reduce Metal Artifacts of Cerebral Aneurysm Embolism Coils. Clin Neuroradiol 2022; 32:687-694. [DOI: 10.1007/s00062-021-01125-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 11/17/2021] [Indexed: 11/03/2022]
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Shinohara Y, Ohmura T, Sasaki F, Inomata T, Itoh T, Kinoshita T. Appropriate iMAR presets for metal artifact reduction from surgical clips and titanium burr hole covers on postoperative non-contrast brain CT. Eur J Radiol 2021; 141:109811. [PMID: 34102563 DOI: 10.1016/j.ejrad.2021.109811] [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] [Received: 07/03/2020] [Revised: 05/27/2021] [Accepted: 06/01/2021] [Indexed: 10/21/2022]
Abstract
PURPOSE To evaluate suitable iterative metal artifact reduction (iMAR) presets for titanium neurosurgical clips and burr hole covers (BHCs) on postoperative non-contrast computed tomography (NCCT). METHOD Twenty-two patients who underwent NCCT after intracranial aneurysmal clipping were included. NCCT images were postprocessed using eight currently available iMAR presets. In each image, a circular region of interest (ROI) was placed around clip, BHC, and on parietal lobe as reference. Standard deviation (SD) and attenuation value (HU) were measured in each ROI to obtain artifact index (AI) and contrast-to-noise ratio (CNR). For each iMAR preset, SD, AI, HU, and CNR were compared with those without iMAR for clips and BHCs. Visual assessment around each clip and BHC was performed by two neuroradiologists using three-point visual score (VS) (1 = no apparent, 2 = minor, and 3 = severe artifacts). RESULTS Among the presets, the neuro-coils preset (iMAR-NC) showed the lowest SD, AI, and VS for clips (P < 0.001). For BHCs, HU, CNR, and VS with iMAR-NC were significantly higher than those without iMAR (P < 0.001). SD, AI, and VS with the shoulder implants preset (iMAR-ShI) were significantly lower than those without iMAR for clips (P = 0.002, 0.002, and P < 0.001, respectively). For BHCs, VS with iMAR-ShI was lowest among the presets (P = 0.004). CONCLUSIONS Although iMAR-NC reduces metal artifacts from clips, it strengthens artifacts from BHCs. For postoperative NCCT, iMAR-ShI most effectively reduces metal artifacts from both clips and BHCs in a single preset.
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Affiliation(s)
- Yuki Shinohara
- Department of Radiology and Nuclear Medicine, Research Institute for Brain and Blood Vessels-Akita, 6-10 Senshu-kubota-machi, Akita, 010-0874, Japan.
| | - Tomomi Ohmura
- Department of Radiology and Nuclear Medicine, Research Institute for Brain and Blood Vessels-Akita, 6-10 Senshu-kubota-machi, Akita, 010-0874, Japan.
| | - Fumiaki Sasaki
- Department of Radiology and Nuclear Medicine, Research Institute for Brain and Blood Vessels-Akita, 6-10 Senshu-kubota-machi, Akita, 010-0874, Japan.
| | - Takato Inomata
- Department of Radiology and Nuclear Medicine, Research Institute for Brain and Blood Vessels-Akita, 6-10 Senshu-kubota-machi, Akita, 010-0874, Japan.
| | - Toshihide Itoh
- CT Research and Collaboration Department, Diagnostic Imaging Division, Siemens Healthcare K.K., Gate City Osaki West Tower 1-11-1 Osaki, Shinagawa-ku, Tokyo, 141-8644, Japan.
| | - Toshibumi Kinoshita
- Department of Radiology and Nuclear Medicine, Research Institute for Brain and Blood Vessels-Akita, 6-10 Senshu-kubota-machi, Akita, 010-0874, Japan.
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Do TD, Heim J, Skornitzke S, Melzig C, Vollherbst DF, Faerber M, Pereira PL, Kauczor HU, Sommer CM. Single-energy versus dual-energy imaging during CT-guided biopsy using dedicated metal artifact reduction algorithm in an in vivo pig model. PLoS One 2021; 16:e0249921. [PMID: 33901200 PMCID: PMC8075226 DOI: 10.1371/journal.pone.0249921] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 03/28/2021] [Indexed: 11/23/2022] Open
Abstract
Purpose To evaluate dual-energy CT (DE) and dedicated metal artifact reduction algorithms (iMAR) during CT-guided biopsy in comparison to single-energy CT (SE). Methods A trocar was placed in the liver of six pigs. CT acquisitions were performed with SE and dose equivalent DE at four dose levels(1.7–13.5mGy). Iterative reconstructions were performed with and without iMAR. ROIs were placed in four positions e.g. at the trocar tip(TROCAR) and liver parenchyma adjacent to the trocar tip(LIVER-1) by two independent observers for quantitative analysis using CT numbers, noise, SNR and CNR. Qualitative image analysis was performed regarding overall image quality and artifacts generated by iMAR. Results There were no significant differences in CT numbers between DE and SE at TROCAR and LIVER-1 irrespective of iMAR. iMAR significantly reduced metal artifacts at LIVER-1 for all exposure settings for DE and SE(p = 0.02-0.04), but not at TROCAR. SNR, CNR and noise were comparable for DE and SE. SNR was best for high dose levels of 6.7/13.5mGy. Mean difference in the Blant-Altman analysis was -8.43 to 0.36. Cohen’s kappa for qualitative interreader-agreement was 0.901. Conclusions iMAR independently reduced metal artifacts more effectively and efficiently than CT acquisition in DE at any dose setting and its application is feasible during CT-guided liver biopsy.
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Affiliation(s)
- Thuy Duong Do
- Clinic for Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany
- * E-mail:
| | - Julia Heim
- Clinic for Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany
| | - Stephan Skornitzke
- Clinic for Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany
| | - Claudius Melzig
- Clinic for Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany
| | | | - Michael Faerber
- Clinic for Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany
| | - Philippe L. Pereira
- Clinic for Radiology, Minimally-invasive Therapies and Nuclear Medicine, SLK Kliniken Heilbronn GmbH, Heilbronn, Germany
| | - Hans-Ulrich Kauczor
- Clinic for Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany
| | - Christof Matthias Sommer
- Clinic for Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany
- Clinic for Diagnostic and Interventional Radiology, Klinikum Stuttgart, Stuttgart, Germany
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Reduction of CT artifacts from cardiac implantable electronic devices using a combination of virtual monoenergetic images and post-processing algorithms. Eur Radiol 2021; 31:7151-7161. [PMID: 33630164 PMCID: PMC8379133 DOI: 10.1007/s00330-021-07746-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 12/16/2020] [Accepted: 02/04/2021] [Indexed: 12/20/2022]
Abstract
OBJECTIVES To evaluate the reduction of artifacts from cardiac implantable electronic devices (CIEDs) by virtual monoenergetic images (VMI), metal artifact reduction (MAR) algorithms, and their combination (VMIMAR) derived from spectral detector CT (SDCT) of the chest compared to conventional CT images (CI). METHODS In this retrospective study, we included 34 patients (mean age 74.6 ± 8.6 years), who underwent a SDCT of the chest and had a CIED in place. CI, MAR, VMI, and VMIMAR (10 keV increment, range: 100-200 keV) were reconstructed. Mean and standard deviation of attenuation (HU) among hypo- and hyperdense artifacts adjacent to CIED generator and leads were determined using ROIs. Two radiologists qualitatively evaluated artifact reduction and diagnostic assessment of adjacent tissue. RESULTS Compared to CI, MAR and VMIMAR ≥ 100 keV significantly increased attenuation in hypodense and significantly decreased attenuation in hyperdense artifacts at CIED generator and leads (p < 0.05). VMI ≥ 100 keV alone only significantly decreased hyperdense artifacts at the generator (p < 0.05). Qualitatively, VMI ≥ 100 keV, MAR, and VMIMAR ≥ 100 keV provided significant reduction of hyper- and hypodense artifacts resulting from the generator and improved diagnostic assessment of surrounding structures (p < 0.05). Diagnostic assessment of structures adjoining to the leads was only improved by MAR and VMIMAR 100 keV (p < 0.05), whereas keV values ≥ 140 with and without MAR significantly worsened diagnostic assessment (p < 0.05). CONCLUSIONS The combination of VMI and MAR as well as MAR as a standalone approach provides effective reduction of artifacts from CIEDs. Still, higher keV values should be applied with caution due to a loss of soft tissue and vessel contrast along the leads. KEY POINTS • The combination of VMI and MAR as well as MAR as a standalone approach enables effective reduction of artifacts from CIEDs. • Higher keV values of both VMI and VMIMAR at CIED leads should be applied with caution since diagnostic assessment can be hampered by a loss of soft tissue and vessel contrast. • Recommended keV values for CIED generators are between 140 and 200 keV and for leads around 100 keV.
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