المؤلفون: Wassipaul, Christian, Janata-Schwatczek, Karin, Domanovits, Hans, Tamandl, Dietmar, Prosch, Helmut, Scharitzer, Martina, Polanec, Stephan, Schernthaner, Ruediger E., Mang, Thomas, Asenbaum, Ulrika, Apfaltrer, Paul, Cacioppo, Filippo, Schuetz, Nikola, Weber, Michael, Homolka, Peter, Birkfellner, Wolfgang, Herold, Christian, Ringl, Helmut

مصطلحات موضوعية: Ultra-low-dose computed tomography, Chest X-ray, Non-traumatic emergency department, Detection rate, Primary imaging modality

جغرافية الموضوع: UMW:14604, UMW:14529, UMW:14636

الوصف: Background Ultra-low-dose CT (ULDCT) examinations of the chest at only twice the radiation dose of a chest X-ray (CXR) now offer a valuable imaging alternative to CXR. This trial prospectively compares ULDCT and CXR for the detection rate of diagnoses and their clinical relevance in a low-prevalence cohort of non-traumatic emergency department patients. Methods In this prospective crossover cohort trial, 294 non-traumatic emergency department patients with a clinically indicated CXR were included between May 2nd and November 26th of 2019 (www.clinicaltrials.gov : NCT03922516 ). All participants received both CXR and ULDCT, and were randomized into two arms with inverse reporting order. The detection rate of CXR was calculated from ‘arm CXR’ (n = 147; CXR first), and of ULDCT from ‘arm ULDCT’ (n = 147; ULDCT first). Additional information reported by the second exam in each arm was documented. From all available clinical and imaging data, expert radiologists and emergency physicians built a compound reference standard, including radiologically undetectable diagnoses, and assigned each finding to one of five clinical relevance categories for the respective patient. Findings Detection rates for main diagnoses by CXR and ULDCT (mean effective dose: 0.22 mSv) were 9.1% (CI [5.2, 15.5]; 11/121) and 20.1% (CI [14.2, 27.7]; 27/134; P = 0.016), respectively. As an additional imaging modality, ULDCT added 9.1% (CI [5.2, 15.5]; 11/121) of main diagnoses to prior CXRs, whereas CXRs did not add a single main diagnosis (0/134; P < 0.001). Notably, ULDCT also offered higher detection rates than CXR for all other clinical relevance categories, including findings clinically irrelevant for the respective emergency department visit with 78.5% (CI [74.0, 82.5]; 278/354) vs. 16.2% (CI [12.7, 20.3]; 58/359) as a primary modality and 68.2% (CI [63.3, 72.8]; 245/359) vs. 2.5% (CI [1.3, 4.7]; 9/354) as an additional imaging modality. Interpretation In non-traumatic emergency department patients, ULDCT of the chest offered more than ...

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العلاقة: vignette : https://repositorium.meduniwien.ac.at/titlepage/urn/urn:nbn:at:at-ubmuw:3-84874/128Test; urn:nbn:at:at-ubmuw:3-84874; https://resolver.obvsg.at/urn:nbn:at:at-ubmuw:3-84874Test; local:99147763738803331; system:AC17015155

الإتاحة: https://doi.org/10.1016/j.eclinm.2023.102267Test
https://resolver.obvsg.at/urn:nbn:at:at-ubmuw:3-84874Test

المؤلفون: Wassipaul, Christian, Janata-Schwatczek, Karin, Domanovits, Hans, Tamandl, Dietmar, Prosch, Helmut, Scharitzer, Martina, Polanec, Stephan, Schernthaner, Ruediger E., Mang, Thomas, Asenbaum, Ulrika, Apfaltrer, Paul, Cacioppo, Filippo, Schuetz, Nikola, Weber, Michael, Homolka, Peter, Birkfellner, Wolfgang, Herold, Christian, Ringl, Helmut

المساهمون: Siemens Healthineers

المصدر: eClinicalMedicine ; volume 65, page 102267 ; ISSN 2589-5370

مصطلحات موضوعية: General Medicine

الإتاحة: https://doi.org/10.1016/j.eclinm.2023.102267Test
https://api.elsevier.com/content/article/PII:S2589537023004443?httpAccept=text/xmlTest
https://api.elsevier.com/content/article/PII:S2589537023004443?httpAccept=text/plainTest

المؤلفون: Watzenboeck, Martin L., Beer, Lucian, Kifjak, Daria, Röhrich, Sebastian, Heidinger, Benedikt H., Prayer, Florian, Milos, Ruxandra-Iulia, Apfaltrer, Paul, Langs, Georg, Baltzer, Pascal A. T., Prosch, Helmut

المصدر: Cancers; Apr2024, Vol. 16 Issue 8, p1519, 17p

مصطلحات موضوعية: RECEIVER operating characteristic curves, RESEARCH funding, RADIOMICS, LOGISTIC regression analysis, COMPUTED tomography, PROSTATE tumors, CANCER patients, MAGNETIC resonance imaging, RETROSPECTIVE studies, PATIENT-centered care, LUNG tumors, MACHINE learning, LUNG cancer, CONFIDENCE intervals, CONTRAST media

مستخلص: Simple Summary: Radiomics is the extraction of high-dimensional quantitative features from medical images. These features have shown potential to provide diagnostic and prognostic information in various oncological settings, but their reproducibility and stability can be affected by multiple physiological and technical factors. In this study, we assessed the effect of contrast agent timing on radiomics features using dynamic contrast-enhanced CT or MRI in prostate and lung cancers, whereby multiple images are acquired with a high temporal resolution after contrast agent application. We observed that a substantial number of radiomics features are contrast perfusion dependent and prone to bias. Therefore, when using contrast-enhanced scans for radiomics studies, patient-specific perfusion timing (e.g., test bolus protocol) should be applied. Background: The reproducibility of radiomics features extracted from CT and MRI examinations depends on several physiological and technical factors. The aim was to evaluate the impact of contrast agent timing on the stability of radiomics features using dynamic contrast-enhanced perfusion CT (dceCT) or MRI (dceMRI) in prostate and lung cancers. Methods: Radiomics features were extracted from dceCT or dceMRI images in patients with biopsy-proven peripheral prostate cancer (pzPC) or biopsy-proven non-small cell lung cancer (NSCLC), respectively. Features that showed significant differences between contrast phases were identified using linear mixed models. An L2-penalized logistic regression classifier was used to predict class labels for pzPC and unaffected prostate regions-of-interest (ROIs). Results: Nine pzPC and 28 NSCLC patients, who were imaged with dceCT and/or dceMRI, were included in this study. After normalizing for individual enhancement patterns by defining seven individual phases based on a reference vessel, 19, 467 and 128 out of 1204 CT features showed significant temporal dynamics in healthy prostate parenchyma, prostate tumors and lung tumors, respectively. CT radiomics-based classification accuracy of healthy and tumor ROIs was highly dependent on contrast agent phase. For dceMRI, 899 and 1027 out of 1118 features were significantly dependent on time after contrast agent injection for prostate and lung tumors. Conclusions: CT and MRI radiomics features in both prostate and lung tumors are significantly affected by interindividual differences in contrast agent dynamics. [ABSTRACT FROM AUTHOR]

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المؤلفون: Boehm, Panja M., Schwarz, Stefan, Thanner, Jürgen, Veraar, Cecilia, Gerges, Mario, Gerges, Christian, Lang, Irene, Apfaltrer, Paul, Prosch, Helmut, Taghavi, Shahrokh, Klepetko, Walter, Ankersmit, Hendrik Jan, Moser, Bernhard

المصدر: JTCVS Open ; volume 10, page 62-72 ; ISSN 2666-2736

مصطلحات موضوعية: Cardiology and Cardiovascular Medicine, Pulmonary and Respiratory Medicine, Surgery

الإتاحة: https://doi.org/10.1016/j.xjon.2022.02.018Test
https://api.elsevier.com/content/article/PII:S2666273622000821?httpAccept=text/xmlTest
https://api.elsevier.com/content/article/PII:S2666273622000821?httpAccept=text/plainTest

المؤلفون: Trebeschi, Stefano, Bodalal, Zuhir, van Dijk, Nick, Boellaard, Thierry N, Apfaltrer, Paul, Tareco Bucho, Teresa M, Nguyen-Kim, Thi Dan Linh, van der Heijden, Michiel S, Aerts, Hugo J W L, Beets-Tan, Regina G H

المصدر: Trebeschi, Stefano; Bodalal, Zuhir; van Dijk, Nick; Boellaard, Thierry N; Apfaltrer, Paul; Tareco Bucho, Teresa M; Nguyen-Kim, Thi Dan Linh; van der Heijden, Michiel S; Aerts, Hugo J W L; Beets-Tan, Regina G H (2021). Development of a Prognostic AI-Monitor for Metastatic Urothelial Cancer Patients Receiving Immunotherapy. Frontiers in Oncology, 11:637804.

مصطلحات موضوعية: Clinic for Diagnostic and Interventional Radiology, 610 Medicine & health

الوصف: Background: Immune checkpoint inhibitor efficacy in advanced cancer patients remains difficult to predict. Imaging is the only technique available that can non-invasively provide whole body information of a patient's response to treatment. We hypothesize that quantitative whole-body prognostic information can be extracted by leveraging artificial intelligence (AI) for treatment monitoring, superior and complementary to the current response evaluation methods. Methods: To test this, a cohort of 74 stage-IV urothelial cancer patients (37 in the discovery set, 37 in the independent test, 1087 CTs), who received anti-PD1 or anti-PDL1 were retrospectively collected. We designed an AI system [named prognostic AI-monitor (PAM)] able to identify morphological changes in chest and abdominal CT scans acquired during follow-up, and link them to survival. Results: Our findings showed significant performance of PAM in the independent test set to predict 1-year overall survival from the date of image acquisition, with an average area under the curve (AUC) of 0.73 (p < 0.001) for abdominal imaging, and 0.67 AUC (p < 0.001) for chest imaging. Subanalysis revealed higher accuracy of abdominal imaging around and in the first 6 months of treatment, reaching an AUC of 0.82 (p < 0.001). Similar accuracy was found by chest imaging, 5-11 months after start of treatment. Univariate comparison with current monitoring methods (laboratory results and radiological assessments) revealed higher or similar prognostic performance. In multivariate analysis, PAM remained significant against all other methods (p < 0.001), suggesting its complementary value in current clinical settings. Conclusions: Our study demonstrates that a comprehensive AI-based method such as PAM, can provide prognostic information in advanced urothelial cancer patients receiving immunotherapy, leveraging morphological changes not only in tumor lesions, but also tumor spread, and side-effects. Further investigations should focus beyond anatomical imaging. ...

وصف الملف: application/pdf

العلاقة: https://www.zora.uzh.ch/id/eprint/203384/1/fonc-11-637804.pdfTest; info:pmid/33889546; urn:issn:2234-943X

الإتاحة: https://doi.org/10.5167/uzh-20338410.3389/fonc.2021.637804Test
https://www.zora.uzh.ch/id/eprint/203384Test/
https://www.zora.uzh.ch/id/eprint/203384/1/fonc-11-637804.pdfTest

المؤلفون: Wressnegger, Alexander, Prosch, Helmut, Moser, Bernhard, Klepetko, Walter, Jaksch, Peter, Lambers, Christopher, Hoetzenecker, Konrad, Schestak, Christian, De Bettignies, Albert, Beer, Lucian, Apfaltrer, Georg, Ringl, Helmut, Apfaltrer, Paul

مصطلحات موضوعية: Algorithms, Female, Humans, Image Processing, Computer-Assisted, Lung Diseases, Lung Transplantation, Male, Middle Aged, Radiation Dosage, Radiographic Image Enhancement, Radiographic Image Interpretation, Radiography, Thoracic, Retrospective Studies, Signal-To-Noise Ratio, Tin, Tomography, X-Ray Computed

الوصف: OBJECTIVES: The purpose of this study was to investigate the impact of a 150kV spectral filtration chest imaging protocol (Sn150kVp) combined with advanced modeled iterative reconstruction (ADMIRE) on radiation dose and image quality in patients after lung-transplantation. METHODS: This study included 102 patients who had unenhanced chest-CT examinations available on both, a second-generation dual-source CT (DSCT) using standard protocol (100kVp, filtered-back-projection) and, on a third-generation DSCT using Sn150kVp protocol with ADMIRE. Signal-to-noise-ratio (SNR) was measured in 6 standardized regions. A 5-point Likert scale was used to evaluate subjective image quality. Radiation metrics were compared. RESULTS: The mean time interval between the two acquisitions was 1.1±0.7 years. Mean-volume-CT-dose-index, dose-length-product and effective dose were significantly lower for Sn150kVp protocol (2.1±0.5mGy;72.6±16.9mGy*cm;1.3±0.3mSv) compared to 100kVp protocol (6.2±1.8mGy;203.6±55.6mGy*cm;3.7±1.0mSv) (p<0.001), equaling a 65% dose reduction. All studies were considered of diagnostic quality. SNR measured in lung tissue, air inside trachea, vertebral body and air outside the body was significantly higher in 100kVp protocol compared to Sn150kVp protocol (12.5±2.7vs.9.6±1.5;17.4±3.6vs.11.8±1.8;0.7±0.3vs.0.4±0.2;25.2±6.9vs.14.9±3.3;p<0.001). SNR measured in muscle tissue was significantly higher in Sn150kVp protocol (3.2±0.9vs.2.6±1.0;p<0.001). For SNR measured in descending aorta there was a trend towards higher values for Sn150kVp protocol (2.8±0.6 vs. 2.7±0.9;p = 0.3). Overall SNR was significantly higher in 100kVp protocol (5.0±4.0vs.4.0±4.0;p<0.001). On subjective analysis both protocols achieved a median Likert rating of 1 (25th-75th-percentile:1-1;p = 0.122). Interobserver agreement was good (intraclass correlation coefficient = 0.73). CONCLUSIONS: Combined use of 150kVp tin-filtered chest CT protocol with ADMIRE allows for significant dose reduction while maintaining highly diagnostic image ...

وصف الملف: Electronic-eCollection; application/pdf

العلاقة: https://www.repository.cam.ac.uk/handle/1810/304078Test

الإتاحة: https://doi.org/10.17863/CAM.51160Test
https://www.repository.cam.ac.uk/handle/1810/304078Test

المؤلفون: Beer, Lucian, Polanec, Stephan H, Baltzer, Pascal AT, Schatzl, Georg, Georg, Dietmar, Schestak, Christian, Dutschke, Anja, Herrmann, Harald, Mazal, Peter, Brendel, Alexander K, Shariat, Shahrokh F, Ringl, Helmut, Helbich, Thomas H, Apfaltrer, Paul

مصطلحات موضوعية: Aged, Biopsy, Large-Core Needle, Contrast Media, Diffusion Magnetic Resonance Imaging, Feasibility Studies, Four-Dimensional Computed Tomography, Humans, Image-Guided Biopsy, Male, Middle Aged, Neoplasm Grading, Perfusion Imaging, Proof of Concept Study, Prospective Studies, Prostate, Prostatic Neoplasms, Radiation Dosage, Radiotherapy Planning, Computer-Assisted, Radiotherapy, Image-Guided

الوصف: PURPOSE: Advanced forms of prostate cancer (PCa) radiotherapy with either external beam therapy or brachytherapy delivery techniques aim for a focal boost and thus require accurate lesion localization and lesion segmentation for subsequent treatment planning. This study prospectively evaluated dynamic contrast-enhanced computed tomography (DCE-CT) for the detection of prostate cancer lesions in the peripheral zone (PZ) using qualitative and quantitative image analysis compared to multiparametric magnet resonance imaging (mpMRI) of the prostate. METHODS: With local ethics committee approval, 14 patients (mean age, 67 years; range, 57-78 years; PSA, mean 8.1 ng/ml; range, 3.5-26.0) underwent DCE-CT, as well as mpMRI of the prostate, including standard T2, diffusion-weighted imaging (DWI), and DCE-MRI sequences followed by transrectal in-bore MRI-guided prostate biopsy. Maximum intensity projections (MIP) and DCE-CT perfusion parameters (CTP) were compared between healthy and malignant tissue. Two radiologists independently rated image quality and the tumor lesion delineation quality of PCa using a five-point ordinal scale. MIP and CTP were compared using visual grading characteristics (VGC) and receiver operating characteristics (ROC)/area under the curve (AUC) analysis. RESULTS: The PCa detection rate ranged between 57 to 79% for the two readers for DCE-CT and was 92% for DCE-MRI. DCE-CT perfusion parameters in PCa tissue in the PZ were significantly different compared to regular prostate tissue and benign lesions. Image quality and lesion visibility were comparable between DCE-CT and DCE-MRI (VGC: AUC 0.612 and 0.651, p>0.05). CONCLUSION: Our preliminary results suggest that it is feasible to use DCE-CT for identification and visualization, and subsequent segmentation for focal radiotherapy approaches to PCa.

وصف الملف: Electronic-eCollection; application/pdf

العلاقة: https://www.repository.cam.ac.uk/handle/1810/301657Test

الإتاحة: https://doi.org/10.17863/CAM.48728Test
https://www.repository.cam.ac.uk/handle/1810/301657Test

المؤلفون: Apfaltrer, Paul, Beer, Lucian, Toepker, Michael, Ba-Ssalamah, Ahmed, Schestak, Christian, Dutschke, Anja, Schindl, Martin, Wressnegger, Alexander, Ringl, Helmut

مصطلحات موضوعية: Pancreatic neoplasms, Multidetector computed tomography, Signal-to-noise ratio

جغرافية الموضوع: UMW:14610, UMW:14636

الوصف: Objectives The aim of this study was to assess the objective and subjective image characteristics of monoenergetic images (MEI[+]), using a noise-optimized algorithm at different kiloelectron volts (keV) compared to polyenergetic images (PEI), in patients with pancreatic ductal adenocarcinoma (PDAC). Methods This retrospective, institutional review board-approved study included 45 patients (18 male, 27 female; mean age 66 years; range, 42–96 years) with PDAC who had undergone a dual-energy CT (DECT) of the abdomen for staging. One standard polyenergetic image (PEI) and five MEI(+) images in 10-keV intervals, ranging from 40 to 80 keV, were reconstructed. Line-density profile analysis, as well as the contrast-to-noise ratio (CNR) of the tumor, the signal-to-noise ratio (SNR) of the regular pancreas parenchyma and the tumor, and the CNR of the three main peripancreatic vessels, was calculated. For subjective quality assessment, two readers independently assessed the images using a 5-point Likert scale. Reader reliability was evaluated using an intraclass correlation coefficient. Results Line-density profile analysis revealed the largest gradient in attenuation between PDAC and regular tissue in MEI(+) at 40 keV. Low-keV MEI(+)reconstructions at 40 and 50 keV increased CNR and SNR compared to PEI (40 keV: CNR 46.8 vs. 7.5; SNRPankreas 32.5 vs. 15.7; SNRLesion 13.5 vs. 8.6; p < 0.001). MEI(+) at 40 keV and 50 keV were consistently preferred by the observers (p < 0.05), showing a high intra-observer 0.937 (0.92–0.95) and inter-observer 0.911 (0.89–0.93) agreement. Conclusion MEI(+) reconstructions at 40 keV and 50 keV provide better objective and subjective image quality compared to conventional PEI of DECT in patients with PDAC. Key Points • Low-keV MEI(+) reconstructions at 40 and 50 keV increase tumor-to-pancreas contrast compared to PEI. • Low-keV MEI(+) reconstructions improve objective and subjective image quality parameters compared to PEI. • Dual-energy post-processing might be a valuable tool in the ...

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العلاقة: vignette : https://repositorium.meduniwien.ac.at/titlepage/urn/urn:nbn:at:at-ubmuw:3-22593/128Test; urn:nbn:at:at-ubmuw:3-22593; https://resolver.obvsg.at/urn:nbn:at:at-ubmuw:3-22593Test; local:99145449009903331; system:AC15654082

الإتاحة: https://doi.org/10.1007/s00330-019-06116-9Test
https://resolver.obvsg.at/urn:nbn:at:at-ubmuw:3-22593Test

المؤلفون: Ringl, Helmut, Kasparek, Maximilian F., Töpker, Michael, Lazar, Mathias, Weber, Michael, Kasparek, Michael, Mang, Thomas, Apfaltrer, Paul, Kubista, Bend, Windhager, Reinhard

مصطلحات موضوعية: Total knee arthroplasty, Single-energy CT, Dual-energy CT, Blooming artifacts, Streak artifacts, Mono-energetic imaging

جغرافية الموضوع: UMW:14636

الوصف: Purpose To evaluate the influence of different scan parameters for single-energy CT and dual-energy CT, as well as the impact of different material used in a TKA prosthesis on image quality and the extent of metal artifacts. Methods Eight pairs of TKA prostheses from different vendors were examined in a phantom set-up. Each pair consisted of a conventional CoCr prosthesis and the corresponding anti-allergic prosthesis (full titanium, ceramic, or ceramic-coated) from the same vendor. Nine different (seven dual-energy CT and two single-energy CT) scan protocols with different characteristics were used to determine the most suitable CT protocol for TKA imaging. Quantitative image analysis included assessment of blooming artifacts (metal implants appear thicker on CT than they are, given as virtual growth in mm in this paper) and streak artifacts (thick dark lines around metal). Qualitative image analysis was used to investigate the bone–prosthesis interface. Results The full titanium prosthesis and full ceramic knee showed significantly fewer blooming artifacts compared to the standard CoCr prosthesis (mean virtual growth 0.6–2.2 mm compared to 2.9–4.6 mm, p < 0.001). Dual-energy CT protocols showed less blooming (range 3.3–3.8 mm) compared to single-energy protocols (4.6–5.5 mm). The full titanium and full ceramic prostheses showed significantly fewer streak artifacts (mean standard deviation 77–86 Hounsfield unit (HU)) compared to the standard CoCr prosthesis (277–334 HU, p < 0.001). All dual-energy CT protocols had fewer metal streak artifacts (215–296 HU compared to single-energy CT protocols (392–497 HU)). Full titanium and ceramic prostheses were ranked superior with regard to the image quality at the bone/prosthesis interface compared to a standard CoCr prosthesis, and all dual-energy CT protocols were ranked better than single-energy protocols. Conclusions Dual-energy CT and ceramic or titanium prostheses reduce CT artifacts and provide superior image quality of total knee arthroplasty at the ...

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العلاقة: vignette : https://repositorium.meduniwien.ac.at/titlepage/urn/urn:nbn:at:at-ubmuw:3-6393/128Test; urn:nbn:at:at-ubmuw:3-6393; https://resolver.obvsg.at/urn:nbn:at:at-ubmuw:3-6393Test; local:99144949673603331; system:AC15381327

الإتاحة: https://doi.org/10.1007/s00167-018-5001-8Test
https://resolver.obvsg.at/urn:nbn:at:at-ubmuw:3-6393Test

المؤلفون: Beer, Lucian, Toepker, Michael, Ba-Ssalamah, Ahmed, Schestak, Christian, Dutschke, Anja, Schindl, Martin, Wressnegger, Alexander, Ringl, Helmut, Apfaltrer, Paul

المساهمون: Oesterreichische Nationalbank, Theodor Koerner Fond Austria

المصدر: European Radiology ; volume 29, issue 7, page 3617-3625 ; ISSN 0938-7994 1432-1084

مصطلحات موضوعية: Radiology, Nuclear Medicine and imaging, General Medicine

الإتاحة: https://doi.org/10.1007/s00330-019-06116-9Test