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Wolf EV, Müller L, Schoepf UJ, Fink N, Griffith JP, Zsarnoczay E, Baruah D, Suranyi P, Kabakus IM, Halfmann MC, Emrich T, Varga-Szemes A, O'Doherty J. Photon-counting detector CT-based virtual monoenergetic reconstructions: repeatability and reproducibility of radiomics features of an organic phantom and human myocardium. Eur Radiol Exp 2023; 7:59. [PMID: 37875769 PMCID: PMC10597903 DOI: 10.1186/s41747-023-00371-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 07/17/2023] [Indexed: 10/26/2023] Open
Abstract
BACKGROUND Photon-counting detector computed tomography (PCD-CT) may influence imaging characteristics for various clinical conditions due to higher signal and contrast-to-noise ratio in virtual monoenergetic images (VMI). Radiomics analysis relies on quantification of image characteristics. We evaluated the impact of different VMI reconstructions on radiomic features in in vitro and in vivo PCD-CT datasets. METHODS An organic phantom consisting of twelve samples (four oranges, four onions, and four apples) was scanned five times. Twenty-three patients who had undergone coronary computed tomography angiography on a first generation PCD-CT system with the same image acquisitions were analyzed. VMIs were reconstructed at 6 keV levels (40, 55, 70, 90, 120, and 190 keV). The phantoms and the patients' left ventricular myocardium (LVM) were segmented for all reconstructions. Ninety-three original radiomic features were extracted. Repeatability and reproducibility were evaluated through intraclass correlations coefficient (ICC) and post hoc paired samples ANOVA t test. RESULTS There was excellent repeatability for radiomic features in phantom scans (all ICC = 1.00). Among all VMIs, 36/93 radiomic features (38.7%) in apples, 28/93 (30.1%) in oranges, and 33/93 (35.5%) in onions were not significantly different. For LVM, the percentage of stable features was high between VMIs ≥ 90 keV (90 versus 120 keV, 77.4%; 90 versus 190 keV, 83.9%; 120 versus 190 keV, 89.3%), while comparison to lower VMI levels led to fewer reproducible features (40 versus 55 keV, 8.6%). CONCLUSIONS VMI levels influence the stability of radiomic features in an organic phantom and patients' LVM; stability decreases considerably below 90 keV. RELEVANCE STATEMENT Spectral reconstructions significantly influence radiomic features in vitro and in vivo, necessitating standardization and careful attention to these reconstruction parameters before clinical implementation. KEY POINTS • Radiomic features have an excellent repeatability within the same PCD-CT acquisition and reconstruction. • Differences in VMI lead to decreased reproducibility for radiomic features. • VMI ≥ 90 keV increased the reproducibility of the radiomic features.
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Affiliation(s)
- Elias V Wolf
- Department of Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA
| | - Lukas Müller
- Department of Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - U Joseph Schoepf
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA
| | - Nicola Fink
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA
- Department of Radiology, University Hospital, LMU Munich, Munich, Germany
| | - Joseph P Griffith
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA
| | - Emese Zsarnoczay
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA
- Medical Imaging Centre, Semmelweis University, Budapest, Hungary
| | - Dhiraj Baruah
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA
| | - Pal Suranyi
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA
| | - Ismael M Kabakus
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA
| | - Moritz C Halfmann
- Department of Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
- German Centre for Cardiovascular Research, Partner site Rhine-Main, Mainz, Germany
| | - Tilman Emrich
- Department of Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany.
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA.
- German Centre for Cardiovascular Research, Partner site Rhine-Main, Mainz, Germany.
| | - Akos Varga-Szemes
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA
| | - Jim O'Doherty
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA
- Siemens Medical Solutions USA Inc, Malvern, PA, USA
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Kanatani R, Shirasaka T, Kojima T, Kato T, Kawakubo M. Influence of beam hardening in dual-energy CT imaging: phantom study for iodine mapping, virtual monoenergetic imaging, and virtual non-contrast imaging. Eur Radiol Exp 2021; 5:18. [PMID: 33903993 PMCID: PMC8076398 DOI: 10.1186/s41747-021-00217-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 03/31/2021] [Indexed: 11/14/2022] Open
Abstract
In this study, we investigated the influence of beam hardening on the dual-energy computed tomography (DECT) values of iodine maps, virtual monoenergetic (VME) images, and virtual non-contrast (VNC) images. 320-row DECT imaging was performed by changing the x-ray tube energy for the first and second rotations. DECT values of 5 mg/mL iodine of the multi-energy CT phantom were compared with and without a 2-mm-thick attenuation rubber layer (~700 HU) wound around the phantom. It was found that the CT density values UH, with/without the rubber layer had statistical differences in the iodine map (184 ± 0.7 versus 186 ± 1.8), VME images (125 ± 0.3 versus 110 ± 0.4), and VNC images (−58 ± 0.7 versus −76 ± 1.7) (p < 0.010 for all). This suggests that iodine mapping may be underestimated by DECT and overestimated by VME imaging because of x-ray beam hardening. The use of VNC images instead of plain CT images requires further investigation because of underestimation.
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Affiliation(s)
- Risa Kanatani
- Department of Health Sciences, School of Medical Sciences, Kyushu University, Fukuoka, Japan.,Department of Radiology, Saiseikai Fukuoka General Hospital, Fukuoka, Japan
| | - Takashi Shirasaka
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, Fukuoka, Japan
| | - Tsukasa Kojima
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, Fukuoka, Japan.,Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Toyoyuki Kato
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, Fukuoka, Japan
| | - Masateru Kawakubo
- Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan.
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Spandorfer A, Branch C, Sharma P, Sahbaee P, Schoepf UJ, Ravenel JG, Nance JW. Deep learning to convert unstructured CT pulmonary angiography reports into structured reports. Eur Radiol Exp 2019; 3:37. [PMID: 31549323 PMCID: PMC6757071 DOI: 10.1186/s41747-019-0118-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 07/24/2019] [Indexed: 01/29/2023] Open
Abstract
Background Structured reports have been shown to improve communication between radiologists and providers. However, some radiologists are concerned about resultant decreased workflow efficiency. We tested a machine learning-based algorithm designed to convert unstructured computed tomography pulmonary angiography (CTPA) reports into structured reports. Methods A self-supervised convolutional neural network-based algorithm was trained on a dataset of 475 manually structured CTPA reports. Labels for individual statements included “pulmonary arteries,” “lungs and airways,” “pleura,” “mediastinum and lymph nodes,” “cardiovascular,” “soft tissues and bones,” “upper abdomen,” and “lines/tubes.” The algorithm was applied to a test set of 400 unstructured CTPA reports, generating a predicted label for each statement, which was evaluated by two independent observers. Per-statement accuracy was calculated based on strict criteria (algorithm label counted as correct if the statement unequivocally contained content only related to that particular label) and a modified criteria, accounting for problematic statements, including typographical errors, statements that did not fit well into the classification scheme, statements containing content for multiple labels, etc. Results Of the 4,157 statements, 3,806 (91.6%) and 3,986 (95.9%) were correctly labeled by the algorithm using strict and modified criteria, respectively, while 274 (6.6%) were problematic for the manual observers to label, the majority of which (n = 173) were due to more than one section being included in one statement. Conclusion This algorithm showed high accuracy in converting free-text findings into structured reports, which could improve communication between radiologists and clinicians without loss of productivity and provide more structured data for research/data mining applications.
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Affiliation(s)
- Adam Spandorfer
- Department of Radiology, Medical University of South Carolina, 171 Ashley Avenue, Charleston, SC, 29425, USA
| | - Cody Branch
- Department of Radiology, Medical University of South Carolina, 171 Ashley Avenue, Charleston, SC, 29425, USA
| | - Puneet Sharma
- Siemens Medical Solutions USA, Inc., 40 Liberty Boulevard, Malvern, PA, 19355, USA
| | - Pooyan Sahbaee
- Siemens Medical Solutions USA, Inc., 40 Liberty Boulevard, Malvern, PA, 19355, USA
| | - U Joseph Schoepf
- Department of Radiology, Medical University of South Carolina, 171 Ashley Avenue, Charleston, SC, 29425, USA
| | - James G Ravenel
- Department of Radiology, Medical University of South Carolina, 171 Ashley Avenue, Charleston, SC, 29425, USA
| | - John W Nance
- Department of Radiology, Medical University of South Carolina, 171 Ashley Avenue, Charleston, SC, 29425, USA.
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Trinidad López C, De La Fuente Aguado J, Oca Pernas R, Delgado Sánchez-Gracián C, Santos Armentia E, Vaamonde Liste A, Prada González R, Souto Bayarri M. Evaluation of response to conventional chemotherapy and radiotherapy by perfusion computed tomography in non-small cell lung cancer (NSCLC). Eur Radiol Exp 2019; 3:23. [PMID: 31197486 PMCID: PMC6565789 DOI: 10.1186/s41747-019-0101-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 05/02/2019] [Indexed: 12/16/2022] Open
Abstract
Background To evaluate changes in perfusion computed tomography (PCT) parameters induced by treatment with conventional chemotherapy (CCT) alone or with CCT and radiation therapy (RT) in patients with non-small cell lung cancer (NSCLC) and to determine whether these changes correlate with response as defined by the response evaluation criteria in solid tumours version 1.1 (RECIST-1.1). Methods Fifty-three patients with a histological diagnosis of NSCLC prospectively underwent PCT of the whole tumour, before/after CCT or before/after CCT and RT. Blood flow (BF), blood volume (BV), permeability (PMB), and mean transit time (MTT) were compared before and after treatment and with the response as defined by RECIST-1.1. The relationship between changes in the perfusion parameters and in tumour size was also evaluated. Results PCT parameters decreased after treatment, significantly for BV (p = 0.002) and MTT (p = 0.027). The 30 patients with partial response had a significant decrease of 21% for BV (p = 0.006) and 17% for MTT (p = 0.031). A non-significant decrease in all perfusion parameters was found in patients with stable disease (p > 0.137). In patients with progressive disease, MTT decreased by 10% (p = 0.465) and the other parameters did not significantly vary (p > 0.809). No significant correlation was found between changes in size and PCT parameters (p > 0.145). Conclusions Treatment of NSCLC with platinum derivatives, with or without RT, induces changes in PCT parameters. Partial response is associated with a significant decrease in BV and MTT, attributable to the effect of the treatment on tumour vascularisation.
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Affiliation(s)
- Carmen Trinidad López
- Department of Radiology, POVISA Hospital, 5 Salamanca st, 36208, Vigo, Pontevedra, Spain.
| | | | - Roque Oca Pernas
- Department of Radiology, Osatek, Urduliz Hospital, Vizcaya, Spain
| | | | - Eloisa Santos Armentia
- Department of Radiology, POVISA Hospital, 5 Salamanca st, 36208, Vigo, Pontevedra, Spain
| | - Antonio Vaamonde Liste
- Department of Statistics and Operational Research, Faculty of Economic and Business Sciences, Vigo University Spain, Vigo, Spain
| | - Raquel Prada González
- Department of Radiology, POVISA Hospital, 5 Salamanca st, 36208, Vigo, Pontevedra, Spain
| | - Miguel Souto Bayarri
- Department of Radiology, Complexo Hospitalario Universitario de Santiago de Compostela, Santiago de Compostela, Spain
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O'Neill S, Kavanagh RG, Carey BW, Moore N, Maher M, O'Connor OJ. Using body mass index to estimate individualised patient radiation dose in abdominal computed tomography. Eur Radiol Exp 2018; 2:38. [PMID: 30483977 PMCID: PMC6258803 DOI: 10.1186/s41747-018-0070-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 10/09/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The size-specific dose estimate (SSDE) is a dose-related metrics that incorporates patient size into its calculation. It is usually derived from the volume computed tomography dose index (CTDIvol) by applying a conversion factor determined from manually measured anteroposterior and lateral skin-to-skin patient diameters at the midslice level on computed tomography (CT) localiser images, an awkward, time-consuming, and not highly reproducible technique. The objective of this study was to evaluate the potential for the use of body mass index (BMI) as a size-related metrics alternative to the midslice effective diameter (DE) to obtain a size-specific dose (SSDE) in abdominal CT. METHODS In this retrospective study of patients who underwent abdominal CT for the investigation of inflammatory bowel disease, the DE was measured on the midslice level on CT-localiser images of each patient. This was correlated with patient BMI and the linear regression equation relating the quantities was calculated. The ratio between the internal and the external abdominal diameters (DRATIO) was also measured to assess correlation with radiation dose. Pearson correlation analysis and linear regression models were used. RESULTS There was good correlation between DE and patient BMI (r = 0.88). An equation allowing calculation of DE from BMI was calculated by linear regression analysis as follows: DE = 0.76 (BMI) + 9.4. A weak correlation between radiation dose and DRATIO was demonstrated (r = 0.45). CONCLUSIONS Patient BMI can be used to accurately estimate DE, obviating the need to measure anteroposterior and lateral diameters in order to calculate a SSDE for abdominal CT.
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Affiliation(s)
- Siobhan O'Neill
- Department of Radiology, Cork University Hospital, Wilton, Cork, Ireland.,Department of Radiology, University College Cork, Cork, Ireland
| | - Richard G Kavanagh
- Department of Radiology, Cork University Hospital, Wilton, Cork, Ireland. .,Department of Radiology, University College Cork, Cork, Ireland.
| | - Brian W Carey
- Department of Radiology, University College Cork, Cork, Ireland
| | - Niamh Moore
- Department of Radiology, Cork University Hospital, Wilton, Cork, Ireland
| | - Michael Maher
- Department of Radiology, Cork University Hospital, Wilton, Cork, Ireland.,Department of Radiology, University College Cork, Cork, Ireland.,APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Owen J O'Connor
- Department of Radiology, Cork University Hospital, Wilton, Cork, Ireland.,Department of Radiology, University College Cork, Cork, Ireland.,APC Microbiome Ireland, University College Cork, Cork, Ireland
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Mei K, Ehn S, Oechsner M, Kopp FK, Pfeiffer D, Fingerle AA, Pfeiffer F, Combs SE, Wilkens JJ, Rummeny EJ, Noël PB. Dual-layer spectral computed tomography: measuring relative electron density. Eur Radiol Exp 2018; 2:20. [PMID: 30175319 PMCID: PMC6103960 DOI: 10.1186/s41747-018-0051-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Accepted: 05/25/2018] [Indexed: 11/22/2022] Open
Abstract
Background X-ray and particle radiation therapy planning requires accurate estimation of local electron density within the patient body to calculate dose delivery to tumour regions. We evaluate the feasibility and accuracy of electron density measurement using dual-layer computed tomography (DLCT), a recently introduced dual-energy CT technique. Methods Two calibration phantoms were scanned with DLCT and virtual monoenergetic images (VMIs) at 50 keV and 200 keV were generated. We investigated two approaches to obtain relative electron densities from these VMIs: to fit an analytic interaction cross-sectional model and to empirically calibrate a conversion function with one of the phantoms. Knowledge of the emitted x-ray spectrum was not required for the presented work. Results The results from both methods were highly correlated to the nominal values (R > 0.999). Except for the water and lung inserts, the error was within 1.79% (average 1.53%) for the cross-sectional model and 1.61% (average 0.87%) for the calibrated conversion. Different radiation doses did not have a significant influence on the measurement (p = 0.348, 0.167), suggesting that the methods are reproducible. Further, we applied these methods to routine clinical data. Conclusions Our study shows a high validity of electron density estimation based on DLCT, which has potential to improve the procedure and accuracy of measuring electron density in clinical practice.
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Affiliation(s)
- Kai Mei
- Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Sebastian Ehn
- 2Department of Physics and Munich School of BioEngineering, Technical University of Munich, Munich, Germany
| | - Markus Oechsner
- Department of Radiation Oncology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Felix K Kopp
- Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Daniela Pfeiffer
- Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany.,2Department of Physics and Munich School of BioEngineering, Technical University of Munich, Munich, Germany
| | - Alexander A Fingerle
- Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Franz Pfeiffer
- Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany.,2Department of Physics and Munich School of BioEngineering, Technical University of Munich, Munich, Germany
| | - Stephanie E Combs
- Department of Radiation Oncology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Jan J Wilkens
- Department of Radiation Oncology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Ernst J Rummeny
- Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Peter B Noël
- Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany.,2Department of Physics and Munich School of BioEngineering, Technical University of Munich, Munich, Germany
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