79 results on '"Widmann G"'
Search Results
2. Integration of multimodality imaging and surgical navigation in the management of patients with refractory epilepsy. A pilot study using a new minimally invasive reference and head-fixation system
- Author
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Ortler, M., Trinka, E., Dobesberger, J., Bauer, R., Unterhofer, C., Twerdy, K., Walser, G., Unterberger, I., Donnemiller, E., Gotwald, T., Widmann, G., and Bale, R.
- Published
- 2010
- Full Text
- View/download PDF
3. P6149Coronary computed tomographic angiography (CTA) for risk stratification in the diagnostic triage of patients undergoing liver transplantation (LT): A long-term outcome study
- Author
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Strobl, S, primary, Senoner, T, additional, Finkenstedt, A, additional, Widmann, G, additional, Plank, F, additional, Zoller, H, additional, Steinkohl, F, additional, Friedrich, G, additional, and Feuchtner, G M, additional
- Published
- 2019
- Full Text
- View/download PDF
4. Wave shapes in alternating DSC
- Author
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Schenker, B., Widmann, G., Riesen, R., Schenker, B., Widmann, G., and Riesen, R.
- Abstract
ADSC with its periodical temperature programs combines the features of DSC measured at high heating rate (high sensitivity) with those at low heating rate (high temperature resolution). In addition, the "reversing” cp effects can be separated from the "non-reversing” latent heat effects. Various periodical temperature programs can be applied. This paper compares the different possible temperature programs and their algorithms for the cp determination for metal, metal oxide and polymer of various properties. Simulated and measured results for various wave shapes and samples are presented. The relevant sample properties and their influence on the measurements are identified and guiding rules for the proper choice of the various experimental parameters are given. Measurements with different samples, performed with the new METTLER TOLEDO STARe-System, are shown and compared with the simulation results. The simulations and the measurements clearly show that the alternating techniques can yield new information about sample properties, but are susceptible to the proper choice of the various experimental parameters
- Published
- 2018
5. Influence of Ultra-Low-Dose and Iterative Reconstructions on the Visualization of Orbital Soft Tissues on Maxillofacial CT
- Author
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Widmann, G., primary, Juranek, D., additional, Waldenberger, F., additional, Schullian, P., additional, Dennhardt, A., additional, Hoermann, R., additional, Steurer, M., additional, Gassner, E.-M., additional, and Puelacher, W., additional
- Published
- 2017
- Full Text
- View/download PDF
6. Evolution of Yeast Populations during Different Biodynamic Winemaking Processes
- Author
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Guzzon, R., primary, Widmann, G., additional, Settanni, L., additional, Malacarne, M., additional, Francesca, N., additional, and Larcher, R., additional
- Published
- 2016
- Full Text
- View/download PDF
7. Materiali innovativi per la protezione delle botti dalle contaminazioni microbiche
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Guzzon, R., Widmann, G., Bertoldi, D., Nardin, T., Larcher, R., and Nicolini, G.
- Published
- 2013
8. Lipoide
- Author
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Josephson, B., Jungner, G., Reinhold, J. G., Wilson, D. W., Cuny, L., Abe, Y., Kawaguchi, S., Christiani, A. v., Anger, V., Rosenheim, O., Ehrström, R., Täufel, K., Thaler, H., Widmann, G., Kirk, E., Bloor, W. R., Williams, H. H., Erickson, B. N., Avrin, I., Bernstein, S. S., Macy, I. G., Ellis, G., Maynard, L. A., Chopra, R. N., Roy, A. C., Feulgen, R., Grünberg, H., Imhäuser, K., Grau, C. A., Oliva, V., Epstein, E., and Lieb, H.
- Published
- 1941
- Full Text
- View/download PDF
9. Prevenzione e controllo della contaminazione microbica nelle botti da vino
- Author
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Guzzon, R., Widmann, G., Bertoldi, D., and Larcher, R.
- Subjects
Botti da vino ,Vinificazione ,Contaminazioni microbiche - Published
- 2012
10. Vasi vinari in legno: monitoraggio microbiologico ed esperienze di sanitizzazione
- Author
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Guzzon, R., Widmann, G., Malacarne, M., Nicolini, G., and Larcher, R.
- Published
- 2011
11. Approximation of head and neck cancer volumes in contrast enhanced CT
- Author
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Dejaco, D., primary, Url, C., additional, Schartinger, V. H., additional, Haug, A. K., additional, Fischer, N., additional, Riedl, D., additional, Posch, A., additional, Riechelmann, H., additional, and Widmann, G., additional
- Published
- 2015
- Full Text
- View/download PDF
12. Image-guided surgery and medical robotics in the cranial area
- Author
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Widmann G
- Subjects
medicine.medical_specialty ,Surgical instrumentation ,Radiological and Ultrasound Technology ,image-guided surgery ,Computer science ,Surgical care ,Conventional surgery ,Biomedical Engineering ,medical robotics ,Review Article ,Surgical planning ,Image-guided surgery ,Medical robotics ,mechatronic surgical tools ,medicine ,image-to-patient registration accuracy ,Radiology, Nuclear Medicine and imaging ,Medical physics ,Augmented reality - Abstract
Surgery in the cranial area includes complex anatomic situations with high-risk structures and high demands for functional and aesthetic results. Conventional surgery requires that the surgeon transfers complex anatomic and surgical planning information, using spatial sense and experience. The surgical procedure depends entirely on the manual skills of the operator. The development of image-guided surgery provides new revolutionary opportunities by integrating presurgical 3D imaging and intraoperative manipulation. Augmented reality, mechatronic surgical tools, and medical robotics may continue to progress in surgical instrumentation, and ultimately, surgical care. The aim of this article is to review and discuss state-of-the-art surgical navigation and medical robotics, image-to-patient registration, aspects of accuracy, and clinical applications for surgery in the cranial area.
- Published
- 2007
13. Radiologic and Functional Evaluation of Electrode Dislocation from the Scala Tympani to the Scala Vestibuli in Patients with Cochlear Implants
- Author
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Fischer, N., primary, Pinggera, L., additional, Weichbold, V., additional, Dejaco, D., additional, Schmutzhard, J., additional, and Widmann, G., additional
- Published
- 2014
- Full Text
- View/download PDF
14. Brain Computer Interfaces for Communication in Paralysis: a Clinical-Experimental Approach.
- Author
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Hinterberger, T., Nijboer, F., Kübler, A., Matuz, T., Furdea, A., Mochty, U., Jordan, M., Lal, T.N, Hill, J., Mellinger, J., Bensch, M., Tangermann, M., Widmann, G., Elger, C., Rosenstiel, W., Schölkopf, B., Birbaumer, N., Hinterberger, T., Nijboer, F., Kübler, A., Matuz, T., Furdea, A., Mochty, U., Jordan, M., Lal, T.N, Hill, J., Mellinger, J., Bensch, M., Tangermann, M., Widmann, G., Elger, C., Rosenstiel, W., Schölkopf, B., and Birbaumer, N.
- Abstract
An overview of different approaches to brain-computer interfaces (BCIs) developed in our laboratory is given. An important clinical application of BCIs is to enable communication or environmental control in severely paralyzed patients. The BCI 'Thought-Translation Device (TTD)' allows verbal communication through the voluntary self-regulation of brain signals (e.g., slow cortical potentials (SCPs)), which is achieved by operant feedback train-ing. Humans' ability to self-regulate their SCPs is used to move a cursor toward a target that contains a selectable letter set. Two different approaches were followed to develop Web browsers that could be controlled with binary brain responses. Implementing more power-ful classification methods including different signal parameters such as oscillatory features improved our BCI considerably. It was also tested on signals with implanted electrodes. Most BCIs provide the user with a visual feedback interface. Visually impaired patients require an auditory feedback mode. A procedure using auditory (sonified) feedback of multiple EEG parameters was evaluated. Properties of the auditory systems are reported and the results of two experiments with auditory feedback are presented. Clinical data of eight ALS patients demonstrated that all patients were able to acquire efficient brain control of one of the three available BCI systems (SCP, /i-rhythm, and P300), most of them used the SCP-BCI. A controlled comparison of the three systems in a group of ALS patients, however, showed that P300-BCI and the /i-BCI are faster and more easily acquired than SCP-BCI, at least in patients with some rudimentary motor control left. Six patients who started BCI training after entering the completely locked-in state did not achieve reliable communication skills with any BCI system. One completely locked-in patient was able to communicate shortly with a ph-meter, but lost control afterward.
- Published
- 2007
15. Accuracy of Cone-Beam Computed Tomography (CBCT) and Multislice Computed Tomography (MSCT)-Guided Skull Base Surgery Using Different Registration Methods
- Author
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Widmann, G., primary, Fasser, M., additional, Zangerl, A., additional, Schullian, P., additional, Puelacher, W., additional, and Bale, R., additional
- Published
- 2012
- Full Text
- View/download PDF
16. Influence of Modern Low-Dose Multislice Spiral Computed Tomography on Target Registration Errors in Image-Guided Skull Base Surgery
- Author
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Widmann, G., primary, Fasser, M., additional, Schullian, P., additional, Zangerl, A., additional, Puelacher, W., additional, Rasse, M., additional, Riechelmann, H., additional, Bale, R., additional, and Jaschke, W., additional
- Published
- 2012
- Full Text
- View/download PDF
17. Integration of multimodality imaging and surgical navigation in the management of patients with refractory epilepsy. A pilot study using a new minimally invasive reference and head-fixation system
- Author
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Ortler, M., primary, Trinka, E., additional, Dobesberger, J., additional, Bauer, R., additional, Unterhofer, C., additional, Twerdy, K., additional, Walser, G., additional, Unterberger, I., additional, Donnemiller, E., additional, Gotwald, T., additional, Widmann, G., additional, and Bale, R., additional
- Published
- 2009
- Full Text
- View/download PDF
18. Evolution of Yeast Populations during Different Biodynamic Winemaking Processes.
- Author
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Guzzon, R., Widmann, G., Settanni, L., Malacarne, M., Francesca, N., and Larcher, R.
- Subjects
- *
YEAST , *WINES , *FUNGAL populations , *ORGANIC farming , *AGRICULTURAL technology , *FERMENTATION , *BIODIVERSITY , *RNA - Abstract
This work was performed to evaluate the evolution of indigenous yeasts during wine productions carried out following the principles of biodynamic agriculture. Five trials were designed with different technological interventions consisting of the addition of nitrogen (in the form of ammonium salt), thiamine salt, oxygen, and pied de cuvée at varying concentrations. Yeasts were estimated by haemocytometer chamber and plate counts and identified by sequencing of the D1/D2 domain of the 26S rRNA gene. The isolates identified as Saccharomyces cerevisiae were found to dominate must fermentations and were genetically differentiated by interdelta sequence analysis (ISA). Several non-Saccharomyces species, in particular Hanseniaspora spp. and Candida spp., were found at subdominant levels during must fermentation. The trial added with both nitrogen and thiamine (NTV) showed the highest fermentation rate and microbial richness. The internal surfaces of the cellar equipment were characterised by a certain yeast biodiversity and hosted the species found during winemaking; the wooden surfaces represented the primary source of inoculation of a strain of S. cerevisiae found dominant in all winemaking trials. [ABSTRACT FROM AUTHOR]
- Published
- 2011
19. Wave shapes in alternating DSC
- Author
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Schenker, B., Widmann, G., Riesen, R., Schenker, B., Widmann, G., and Riesen, R.
- Abstract
ADSC with its periodical temperature programs combines the features of DSC measured at high heating rate (high sensitivity) with those at low heating rate (high temperature resolution). In addition, the "reversing” cp effects can be separated from the "non-reversing” latent heat effects. Various periodical temperature programs can be applied. This paper compares the different possible temperature programs and their algorithms for the cp determination for metal, metal oxide and polymer of various properties. Simulated and measured results for various wave shapes and samples are presented. The relevant sample properties and their influence on the measurements are identified and guiding rules for the proper choice of the various experimental parameters are given. Measurements with different samples, performed with the new METTLER TOLEDO STARe-System, are shown and compared with the simulation results. The simulations and the measurements clearly show that the alternating techniques can yield new information about sample properties, but are susceptible to the proper choice of the various experimental parameters
20. Tumour ablation: technical aspects.
- Author
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Widmann G, Bodner G, Bale R, Widmann, Gerlig, Bodner, Gerd, and Bale, Reto
- Published
- 2009
- Full Text
- View/download PDF
21. Evolution of yeast populations during different biodynamic winemaking processes
- Author
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Roberto Larcher, Raffaele Guzzon, Luca Settanni, Mario Malacarne, Giacomo Widmann, Nicola Francesca, Guzzon, R, Widmann, G, Settanni, L, Malacarne, M, Francesca, N, and Larcher, R
- Subjects
0301 basic medicine ,Wine ,biology ,030106 microbiology ,Saccharomyces cerevisiae ,food and beverages ,Biodynamic wine, Nutrient addition, Saccharomyces cerevisiae, Typing, Yeasts ,Typing ,biology.organism_classification ,Hanseniaspora ,Yeast ,Nutrient addition ,03 medical and health sciences ,Yeast in winemaking ,Biodynamic wine ,Yeasts ,Botany ,Thiamine ,Fermentation ,Food science ,Winemaking - Abstract
This work was performed to evaluate the evolution of indigenous yeasts during wine productions carried out following the principles of biodynamic agriculture. Five trials were designed with different technological interventions consisting of the addition of nitrogen (in the form of ammonium salt), thiamine salt, oxygen, and pied de cuvee at varying concentrations. Yeasts were estimated by haemocytometer chamber and plate counts and identified by sequencing of the D1/D2 domain of the 26S rRNA gene. The isolates identified as Saccharomyces cerevisiae were found to dominate must fermentations and were genetically differentiated by interdelta sequence analysis (ISA). Several non-Saccharomyces species, in particular Hanseniaspora spp. and Candida spp., were found at subdominant levels during must fermentation. The trial added with both nitrogen and thiamine (NTV) showed the highest fermentation rate and microbial richness. The internal surfaces of the cellar equipment were characterised by a certain yeast biodiversity and hosted the species found during winemaking; the wooden surfaces represented the primary source of inoculation of a strain of S. cerevisiae found dominant in all winemaking trials.
- Published
- 2011
22. Prediction of stroke in patients with severe aortic stenosis by left atrial appendage filling defect patterns on early and late-phase computed tomography.
- Author
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Lacaita PG, Bleckwenn S, Barbieri F, Scharll Y, Deeg J, Bonaros N, Widmann G, and Feuchtner GM
- Abstract
Background: Stroke is a feared complication after TAVI. The objective was to assess whether left atrial appendage (LAA) filling-defect (FD) patterns from early and late-phase computed tomography (CT), predict stroke/TIA in patients with severe aortic stenosis., Methods: 124 patients with severe aortic stenosis (79.5y, 46.8% females) who underwent CT-Angiography for TAVI-planning were included (66.1% underwent TAVI, 18.6% surgical, 15.3% conservative treatment).CT-image-analysis included: CT-density (HU) from LAA tip-to-base and HU-gradients (I-III), the HU-ratio LAA/aorta, left-atrial-wall-thickness (LAWT) and the periatrial fat attenuation index (FAI)., Results: Stroke/TIA rate was 9.6 %. LAA-HU-gradient was slightly higher in non-stroke patients (p = 0.087). Persisting FDs during the late-phase were associated with stroke (p = 0.047) but not early-phase FDs. Early-phase FDs with HU < 245 (n = 15) were correlated with stroke (p = 0.05). A LAA-HU-gradient > 10HU had 91 % sensitivity and 68 % specificity for prediction of stroke. LAA-HU gradient I had a moderate accuracy ( c = 0.592; 95 %CI:0.472-0.711; p = 0.317) for discrimination of stroke during the early phase, which enhanced during the late phase ( c = 0.686 ;95 %CI:0.503-0.868; p = 0.046). Patients with stroke had a higher rate of FDs with HU-progression from early to late phase (>10HU)(p = 0.013), while the ratios LAA/aorta, LAWT, and periatrial-FAI were not different. Among clinical parameters, only age predicted stroke but not CHA2DS2-VASc-score. In multivariate analysis, late-phase FDs (p = 0.059)(OR 5.66: 95 %CI:0.936-34.28) but not early-phase FD were associated with stroke, and none of the major conventional risk factors., Conclusion: Persisting LAA-filling defects on CT during the late-phase, and early-phase FD with <245HU predict stroke, and a CT-density progression >10HU from early-to-late phase. LAA-FD may improve stroke risk stratification., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF
23. Coronary Computed Tomography Angiography (CTA) Findings in COVID-19.
- Author
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Lacaita PG, Luger A, Plank F, Barbieri F, Beyer C, Thurner T, Scharll Y, Deeg J, Widmann G, and Feuchtner GM
- Abstract
(1) Background: The novel SARS-CoV-2 virus infects the endothelium. Vasculitis may lead to specific coronary artery wall lesions. Coronary computed tomography angiography (CTA) imaging findings have not been systematically reported. The aim of this study was to describe a case series using CTA. (2) Methods: Patients with recent RT-PCR confirmed SARS-CoV-2 infection referred for coronary CTA for clinical indications (e.g., chest pain, troponin+, and ECG abnormalities) were included. Coronary CTA findings, such as atypical coronary lesions suggestive of vasculitis, perivascular inflammation measured by using pericoronary fat attenuation (PCAT) index, coronary artery disease, and extracoronary findings were collected. (3) Results: Results for 12 patients (54.8 ± 22 years; four females) with SARS-CoV-2 infection within 60 days (four acute care and eight stable patients) are reported. Time to positive RT-PCR was a mean of 15.1 days (range, 0-51). In four acute patients with signs of myocardial injury, plaque rupture (n = 1), hyperenhancing myocardium/MINOCA (n = 1), MINOCA (n = 1), and pericarditis with acute heart failure (LVEF 20%) (n = 1) were found. All (100%) had pericardial effusion and signs of perivascular inflammation. Among eight stable patients, pericardial effusion or perivascular inflammation were found in only two (25%). Coronary artery disease was ruled out in five (62.5%) (4) Conclusions: Coronary CTA is a useful imaging modality in the diagnostic work up of patients with COVID-19 infection, and is able to describe coronary and other cardiac abnormalities.
- Published
- 2024
- Full Text
- View/download PDF
24. Lipomatous hypertrophy of the interatrial septum: a distinct adipose tissue type in COPD?
- Author
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Lacaita PG, Kindl B, Plank F, Beyer C, Bilgeri V, Barbieri F, Senoner T, Dichtl W, Tancevski I, Swoboda M, Luger A, Deeg J, Widmann G, and Feuchtner GM
- Abstract
Objective: Lipomatous hypertrophy of the interatrial septum (LHIS) is a distinct section of epicardial adipose tissue. However, its association with COPD is poorly documented., Methods: Patients undergoing coronary computed tomography angiography (CTA) for clinical indications were recruited retrospectively and screened for LHIS and COPD. LHIS density and the coronary artery disease profile were quantified by CTA: stenosis severity (coronary artery disease radiological reporting system (CADRADS)), coronary artery calcium (CAC) and high-risk plaque (HRP). COPD patients with LHIS were matched for age and sex, the major cardiovascular risk factors (CVRFs), and compared to controls., Results: The prevalence of LHIS in all 5466 patients was 5.9%. 151 (72.6%) of 208 patients with COPD had LHIS. LHIS density in COPD patients was higher (-10.93 HU versus -21.1 HU; p<0.001), despite body mass index (BMI) (28.8 versus 27.01 kg·m
-2 ; p=0.002) being lower. LHIS density was lower in obese (BMI >30 kg·m-2 ) patients (20.4 versus 13.6 HU; p=0.02). BMI was inversely correlated with LHIS density (BetaR -0.031; 95% CI: -0.054- -0.008; p=0.007). LHIS density was associated with COPD, but not with BMI on multivariate models. CAC and coronary stenosis severity (CADRADS and >50% stenosis) were not different (p=0.106, p=0.156 and p=0.350, respectively). HRPs were observed more frequently in COPD patients with severe Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages ≥2 (32.3% versus 20.1%; p=0.044), but not when adding mild GOLD stages., Conclusions: The prevalence of LHIS in COPD patients is high (72.6%), and the adipose tissue density is higher, indicating a higher brown fat component. In obese, patients LHIS density is lower and declines along with BMI. Coronary stenosis severity and calcium were not different; however HRPs were more frequent in severe COPD., Competing Interests: Conflict of interest: None declared., (Copyright ©The authors 2024.)- Published
- 2024
- Full Text
- View/download PDF
25. Does the absence of breast arterial calcification (BAC 0) rule out severe coronary artery disease? A computed tomography angiography study.
- Author
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Deeg J, Swoboda M, Bilgeri V, Lacaita PG, Scharll Y, Luger A, Widmann G, Gruber L, and Feuchtner GM
- Abstract
Background: Cardiovascular risk (CV)-stratification in females is challenging, and current models miss a high proportion at-risk. Breast arterial calcifications (BAC) are independent prognosticators, but their interaction with the coronary artery disease profile by computed tomography (CT) is controverse, and the role of BAC 0 unclear., Objective: to investigate the interaction of BAC with coronary CT outcomes (CAC score, coronary stenosis severity and high-risk plaque (HRP)., Methods: Consecutive patients referred to mammography (MG) and coronary CTA for clinical indications within 1 year were included. Three different age groups were compared (<55 years;55-65 years;>65 years)., Results: 443 patients were included. There were significant age differences for the prevalence of BAC 0 (p<0.001), BAC 0/CAC>300 AU (p=0.0023) and obstructive disease (>50% stenosis)(p=0.0048) but not for high-risk-plaque (HRP)(p=0.4905). High CAC (>300 AU) was present in only 0.82% of females with BAC 0 in less than 55 year, but significantly more often in those above 65 years (p=0.0004;OR=16.58:95% CI: 2.829-361.7) and 55 years with 12.1% and 8.4%. Obstructive coronary disease (>50% stenosis) in BAC 0 was present in 18.2%; with age-dependent differences (10.7% vs 14.7% vs 29.9%) (p=0.0003). The correlation between BAC, CAC and CADRADS was weak (r=0.246 and r=0.243, p<0.001). There was no association of BAC with HRP., Conclusion: BAC 0 rules out severe CAC >300AU in females <55 years only, but not in those above 55 years- with adherent implications for primary prevention. However, BAC 0 does not to rule out obstructive disease and high-risk plaques in symptomatic patients among all age groups., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF
26. Photon-Counting Detector Computed Tomography (PCD-CT): A New Era for Cardiovascular Imaging? Current Status and Future Outlooks.
- Author
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Lacaita PG, Luger A, Troger F, Widmann G, and Feuchtner GM
- Abstract
Photon-counting detector computed tomography (PCD-CT) represents a revolutionary new generation of computed tomography (CT) for the imaging of patients with cardiovascular diseases. Since its commercial market introduction in 2021, numerous studies have identified advantages of this new technology in the field of cardiovascular imaging, including improved image quality due to an enhanced contrast-to-noise ratio, superior spatial resolution, reduced artifacts, and a reduced radiation dose. The aim of this narrative review was to discuss the current scientific literature, and to find answers to the question of whether PCD-CT has yet led to a true step-change and significant progress in cardiovascular imaging.
- Published
- 2024
- Full Text
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27. CT comparison of the nasal airway anterior and posterior to the piriform aperture in patients with and without nasal obstruction.
- Author
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Heppt H, Widmann G, Riechelmann F, Runge A, Riechelmann H, and Giotakis AI
- Subjects
- Humans, Constriction, Pathologic, Nose, Tomography, X-Ray Computed, Nasal Cavity, Nasal Obstruction
- Abstract
Background: Nasal airway stenosis may lie anterior and/or posterior to the piriform aperture. We intended to compare the nasal airway anterior and posterior to the piriform aperture in patients with and without nasal obstruction., Methods: Segmented computed tomography cross-sectional areas of the nasal airway anterior (CT-CSA
ant ) and posterior to the piriform aperture (at the level of the head of the inferior turbinate; CT-CSApost ) were compared between patients with nasal obstruction (cases) and trauma controls. CT-CSA were approximately perpendicular to the direction of the nasal airflow. Anterior to the piriform aperture, they were tilted about 30o , 60o and 90o to the nasal floor. Posterior to the piriform aperture, they were tilted about 50o , 80o and 100o to the nasal floor. In cases, we examined the Pearson's correlation of active anterior rhinomanometry with CT-CSAant and CT-CSApost ., Results: Narrow and bilateral CT-CSApost were similarly large between 56 cases and 56 controls (all p > 0.2). On the contrary, narrow and bilateral CT-CSAant were significantly smaller in cases than in controls (all p < 0.001). The ratio of the size of CT-CSAant-30 to that of CT-CSApost-80 was significantly lower in cases (median: 0.84; lower to upper quartile: 0.55-1.13) than in controls (1.0; 0.88-1.16; Mann-Whitney U test; p = 0.006). Bilateral CT-CSAant correlated significantly with total inspiratory flow (all p < 0.026) in contrast to bilateral CT-CSApost (all p > 0.056)., Conclusions: The nasal airway anterior to the piriform aperture was smaller in patients with nasal obstruction due to skeletal nasal stenosis than that in controls. On the contrary, the nasal airway posterior to the piriform aperture was similarly large between patients with and without nasal obstruction. Furthermore, in patients with nasal obstruction, the anterior nasal airway was narrower compared to that located posterior to it. On the contrary, control patients' anterior nasal airway was as large as the posterior one., (© 2024. The Author(s).)- Published
- 2024
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28. Radiomic Assessment of Radiation-Induced Alterations of Skeletal Muscle Composition in Head and Neck Squamous Cell Carcinoma within the Currently Clinically Defined Optimal Time Window for Salvage Surgery-A Pilot Study.
- Author
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Santer M, Riechelmann H, Hofauer B, Schmutzhard J, Freysinger W, Runge A, Gottfried TM, Zelger P, Widmann G, Kranebitter H, Mangesius S, Mangesius J, Kocher F, and Dejaco D
- Abstract
Patients with locally advanced head and neck squamous cell carcinoma (HNSCC) frequently require primary radiochemotherapy (RCT). Despite intensity modulation, the desired radiation-induced effects observed in HNSCC may also be observed as side effects in healthy tissue, e.g., the sternocleidomastoid muscle (SCM). These side effects (e.g., tissue fibrosis) depend on the interval between the completion of RCT and restaging CT. For salvage surgery, the optimal time window for surgery is currently clinically postulated at between 6 and 12 weeks after completion of RCT. Thus, no extensive tissue fibrosis is to be expected. This interval is based on clinical studies exploring surgical complications. Studies directly exploring radiation-induced changes of the SCM in HNSCC patients are sparse. The present study quantified tissue alterations in the SCM and paravertebral musculature (PVM) after RCT, applying radiomics to determine the optimal time window for salvage surgery. Three radiomic key parameters, (1) volume, (2) mean positivity of pixels (MPP), and (3) uniformity, were extracted with mint Lesion
TM in the staging CTs and restaging CTs of 98 HNSCC patients. Of these, 25 were female, the mean age was 62 (±9.6) years, and 80.9% were UICC Stage IV. The mean restaging interval was 55 (±28; range 29-229) days. Only the mean volume significantly decreased after RCT, from 9.0 to 8.4 and 96.5 to 91.9 mL for the SCM and PVM, respectively (both p = 0.007, both Cohen's d = 0.28). In addition, the mean body mass index (BMI) decreased from 23.9 (±4.2) to 21.0 (±3.6) kg/m² ( p < 0.001; Cohen's d = 0.9). The mean BMI decreased significantly and was correlated with the volume decrease for the SCM (r = 0.27; p = 0.007) and PVM (r = 0.41; p < 0.001). If t -test p -values were adjusted for the BMI decrease, no significant change in volumes for the SCM and PVM was observed (both p > 0.05). The present data support the clinically postulated optimal interval for salvage surgery of 6 to 12 weeks.- Published
- 2023
- Full Text
- View/download PDF
29. PBRM1 mutations might render a subtype of biliary tract cancers sensitive to drugs targeting the DNA damage repair system.
- Author
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Zimmer K, Kocher F, Untergasser G, Kircher B, Amann A, Baca Y, Xiu J, Korn WM, Berger MD, Lenz HJ, Puccini A, Fontana E, Shields AF, Marshall JL, Hall M, El-Deiry WS, Hsiehchen D, Macarulla T, Tabernero J, Pichler R, Khushman M, Manne U, Lou E, Wolf D, Sokolova V, Schnaiter S, Zeimet AG, Gulhati P, Widmann G, and Seeber A
- Abstract
Polybromo-1 (PBRM1) loss of function mutations are present in a fraction of biliary tract cancers (BTCs). PBRM1, a subunit of the PBAF chromatin-remodeling complex, is involved in DNA damage repair. Herein, we aimed to decipher the molecular landscape of PBRM1 mutated (mut) BTCs and to define potential translational aspects. Totally, 1848 BTC samples were analyzed using next-generation DNA-sequencing and immunohistochemistry (Caris Life Sciences, Phoenix, AZ). siRNA-mediated knockdown of PBRM1 was performed in the BTC cell line EGI1 to assess the therapeutic vulnerabilities of ATR and PARP inhibitors in vitro. PBRM1 mutations were identified in 8.1% (n = 150) of BTCs and were more prevalent in intrahepatic BTCs (9.9%) compared to gallbladder cancers (6.0%) or extrahepatic BTCs (4.5%). Higher rates of co-mutations in chromatin-remodeling genes (e.g., ARID1A 31% vs. 16%) and DNA damage repair genes (e.g., ATRX 4.4% vs. 0.3%) were detected in PBRM1-mutated (mut) vs. PBRM1-wildtype (wt) BTCs. No difference in real-world overall survival was observed between PBRM1-mut and PBRM1-wt patients (HR 1.043, 95% CI 0.821-1.325, p = 0.731). In vitro, experiments suggested that PARP ± ATR inhibitors induce synthetic lethality in the PBRM1 knockdown BTC model. Our findings served as the scientific rationale for PARP inhibition in a heavily pretreated PBRM1-mut BTC patient, which induced disease control. This study represents the largest and most extensive molecular profiling study of PBRM1-mut BTCs, which in vitro sensitizes to DNA damage repair inhibiting compounds. Our findings might serve as a rationale for future testing of PARP/ATR inhibitors in PBRM1-mut BTCs., (© 2023. The Author(s).)
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- 2023
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30. Prediction of the as Low as Diagnostically Acceptable CT Dose for Identification of the Inferior Alveolar Canal Using 3D Convolutional Neural Networks with Multi-Balancing Strategies.
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Al-Ekrish A, Hussain SA, ElGibreen H, Almurshed R, Alhusain L, Hörmann R, and Widmann G
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Ionizing radiation is necessary for diagnostic imaging and deciding the right radiation dose is extremely critical to obtain a decent quality image. However, increasing the dosage to improve the image quality has risks due to the potential harm from ionizing radiation. Thus, finding the optimal as low as diagnostically acceptable (ALADA) dosage is an open research problem that has yet to be tackled using artificial intelligence (AI) methods. This paper proposes a new multi-balancing 3D convolutional neural network methodology to build 3D multidetector computed tomography (MDCT) datasets and develop a 3D classifier model that can work properly with 3D CT scan images and balance itself over the heavy unbalanced multi-classes. The proposed models were exhaustively investigated through eighteen empirical experiments and three re-runs for clinical expert examination. As a result, it was possible to confirm that the proposed models improved the performance by an accuracy of 5% to 10% when compared to the baseline method. Furthermore, the resulting models were found to be consistent, and thus possibly applicable to different MDCT examinations and reconstruction techniques. The outcome of this paper can help radiologists to predict the suitability of CT dosages across different CT hardware devices and reconstruction algorithms. Moreover, the developed model is suitable for clinical application where the right dose needs to be predicted from numerous MDCT examinations using a certain MDCT device and reconstruction technique.
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- 2023
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31. COVID-19 and its continuing burden after 12 months: a longitudinal observational prospective multicentre trial.
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Sahanic S, Tymoszuk P, Luger AK, Hüfner K, Boehm A, Pizzini A, Schwabl C, Koppelstätter S, Kurz K, Asshoff M, Mosheimer-Feistritzer B, Coen M, Pfeifer B, Rass V, Egger A, Hörmann G, Sperner-Unterweger B, Helbok R, Wöll E, Weiss G, Widmann G, Tancevski I, Sonnweber T, and Löffler-Ragg J
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Background: Recovery trajectories from coronavirus disease 2019 (COVID-19) call for longitudinal investigation. We aimed to characterise the kinetics and status of clinical, cardiopulmonary and mental health recovery up to 1 year following COVID-19., Methods: Clinical evaluation, lung function testing (LFT), chest computed tomography (CT) and transthoracic echocardiography were conducted at 2, 3, 6 and 12 months after disease onset. Submaximal exercise capacity, mental health status and quality of life were assessed at 12 months. Recovery kinetics and patterns were investigated by mixed-effect logistic modelling, correlation and clustering analyses. Risk of persistent symptoms and cardiopulmonary abnormalities at the 1-year follow-up were modelled by logistic regression., Findings: Out of 145 CovILD study participants, 108 (74.5%) completed the 1-year follow-up (median age 56.5 years; 59.3% male; 24% intensive care unit patients). Comorbidities were present in 75% (n=81). Key outcome measures plateaued after 180 days. At 12 months, persistent symptoms were found in 65% of participants; 33% suffered from LFT impairment; 51% showed CT abnormalities; and 63% had low-grade diastolic dysfunction. Main risk factors for cardiopulmonary impairment included pro-inflammatory and immunological biomarkers at early visits. In addition, we deciphered three recovery clusters separating almost complete recovery from patients with post-acute inflammatory profile and an enrichment in cardiopulmonary residuals from a female-dominated post-COVID-19 syndrome with reduced mental health status., Conclusion: 1 year after COVID-19, the burden of persistent symptoms, impaired lung function, radiological abnormalities remains high in our study population. Yet, three recovery trajectories are emerging, ranging from almost complete recovery to post-COVID-19 syndrome with impaired mental health., Competing Interests: Conflict of interest: P. Tymoszuk owns the Data Analytics as a Service data science enterprise and is (from May 2021 on) a freelance data scientist working in his own enterprise; he received honoraria for the statistical analysis of the CovILD study. All other authors have no conflict of interest related to this study to declare., (Copyright ©The authors 2023.)
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- 2023
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32. Can ultra-low-dose computed tomography reliably diagnose and classify maxillofacial fractures in the clinical routine?
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Widmann G, Dangl M, Lutz E, Fleckenstein B, Offermanns V, Gassner EM, Puelacher W, and Salbrechter L
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Purpose: Maxillofacial trauma predominantly affects young adults between 20 and 40 years of age. Although radioprotection is a legal requirement, the significant potential of dose reduction in computed tomography (CT) is still underused in the clinical routine. The objective of this study was to evaluate whether maxillofacial fractures can be reliably detected and classified using ultra-low-dose CT., Materials and Methods: CT images of 123 clinical cases with maxillofacial fractures were classified by two readers using the AOCOIAC software and compared with the corresponding results from post-treatment images. In group 1, consisting of 97 patients with isolated facial trauma, pre-treatment CT images at different dose levels (volumetric computed tomography dose index: ultra-low dose, 2.6 mGy; low dose, <10 mGy; and regular dose, <20 mGy) were compared with post-treatment cone-beam computed tomography (CBCT). In group 2, consisting of 31 patients with complex midface fractures, pre-treatment shock room CT images were compared with post-treatment CT at different dose levels or CBCT. All images were presented in random order and classified by 2 readers blinded to the clinical results. All cases with an unequal classification were re-evaluated., Results: In both groups, ultra-low-dose CT had no clinically relevant effect on fracture classification. Fourteen cases in group 2 showed minor differences in the classification code, which were no longer obvious after comparing the images directly to each other., Conclusion: Ultra-low-dose CT images allowed the correct diagnosis and classification of maxillofacial fractures. These results might lead to a substantial reconsideration of current reference dose levels., Competing Interests: Conflict of Interest: None, (Copyright © 2023 by Korean Academy of Oral and Maxillofacial Radiology.)
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- 2023
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33. Pulmonary recovery from COVID-19 in patients with metabolic diseases: a longitudinal prospective cohort study.
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Sonnweber T, Grubwieser P, Pizzini A, Boehm A, Sahanic S, Luger A, Schwabl C, Widmann G, Egger A, Hoermann G, Wöll E, Puchner B, Kaser S, Theurl I, Nairz M, Tymoszuk P, Weiss G, Joannidis M, Löffler-Ragg J, and Tancevski I
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- Humans, Prospective Studies, SARS-CoV-2, Lung diagnostic imaging, COVID-19 complications, Metabolic Diseases complications, Dyslipidemias complications
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The severity of coronavirus disease 2019 (COVID-19) is related to the presence of comorbidities including metabolic diseases. We herein present data from the longitudinal prospective CovILD trial, and investigate the recovery from COVID-19 in individuals with dysglycemia and dyslipidemia. A total of 145 COVID-19 patients were prospectively followed and a comprehensive clinical, laboratory and imaging assessment was performed at 60, 100, 180, and 360 days after the onset of COVID-19. The severity of acute COVID-19 and outcome at early post-acute follow-up were significantly related to the presence of dysglycemia and dyslipidemia. Still, at long-term follow-up, metabolic disorders were not associated with an adverse pulmonary outcome, as reflected by a good recovery of structural lung abnormalities in both, patients with and without metabolic diseases. To conclude, dyslipidemia and dysglycemia are associated with a more severe course of acute COVID-19 as well as delayed early recovery but do not impair long-term pulmonary recovery., (© 2023. The Author(s).)
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- 2023
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34. Reliability of Stereotactic Radiofrequency Ablation (SRFA) for Malignant Liver Tumors: Novice versus Experienced Operators.
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Schullian P, Laimer G, Johnston E, Putzer D, Eberle G, Widmann G, Scharll Y, and Bale R
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Purpose: To compare the results of a novice with those of experienced interventional radiologists (IRs) for stereotactic radiofrequency ablation (SRFA) of malignant liver tumors in terms of safety, technical success, and local tumor control., Methods: A database, including all SRFA procedures performed in a single center between January 2011 and December 2018 was retrospectively analyzed. A total of 39 ablation sessions performed by a novice IR were compared to the results of three more experienced IRs. Comparative SRFA sessions were selected using propensity score matching considering tumor type, age, sex, tumor size, and tumor number as matching variables. Overall, 549 target tumors were treated in 273 sessions. Median tumor size was 2.2 cm (1.0-8.5 cm) for 178 hepatocellular carcinomas (HCCs) and 3.0 cm (0.5-13.0 cm) for 371 metastases. A median of 2 (1-11) tumors were treated per session., Results: No significant differences were observed when comparing the results of more experienced IRs with those of a novice IR regarding the rates of major complications (6.8% [16/234] vs. 5.1% [2/39]; p = 0.477), mortality (1.3% [2/234] vs. 0% [0/39]; p = 0.690), primary technical efficacy (98.5% [525/533] vs. 98.9% [94/95]; p = 0.735), and local recurrence (5.6% [30/533] vs. 5.3% [5/95]; p = 0.886). However, the median planning/placement time was significantly shorter for the experienced IRs (92 min vs. 119 min; p = 0.002)., Conclusions: SRFA is a safe, effective, and reliable treatment option for malignant liver tumors and favorable outcomes can be achieved even by inexperienced operators with minimal supervision.
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- 2023
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35. Identification and characterization of patients being exposed to computed-tomography associated radiation-doses above 100 mSv in a real-life setting.
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Widmann G, Beyer A, Jaschke W, Luger A, Zoller H, Tilg H, Schneeberger S, Wolf D, Gizewski ER, Eder R, Torbica P, and Verius M
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Rationale and Objectives: Patients receiving high cumulative effective doses (CED) from recurrent computed tomography (CT) in a real-life setting are not well identified. Evaluation of causes and patient characteristics may help to define individuals potentially at risk of radiation-induced secondary malignancies., Materials and Methods: Patients who received a CED > 100 mSv from CT scans during October 2012 and April 2020 at a tertiary university center were identified with the help of a radiological radiation dose monitoring system. The primary disease and referral diagnosis, number of CT exams, time period, age, BMI and gender distribution of the 1000 patients with the highest CED were analysed., Results: 3431 patients had a CED of more than 100 mSv, which corresponded to 2.75% of all patients who received a CT exam. From the 1000 patients with the highest CED, mean number of CT exams per patient was 14.6, mean CED was 257 mSv (SD 98, range 177-1339). Mean age of patients was 63.9 years (SD 10.6), male to female ratio 3:2, and mean BMI 28.7 kg/m2 (SD 5.5). 728 (72.9%) patients had cancer. The leading primary diagnosis was liver cirrhosis in 197 patients and 103 patients had a liver transplantation. In patients with liver cirrhosis, 750 exams were indicated for the follow-up of the disease, 662 for the clarification of an acute clinical condition, and 202 for CT-guided stereotactic radiofrequency ablation., Conclusion: Recurrent CT scans of patients with cancer, liver cirrhosis and liver transplantation may lead to critically high CED., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 The Authors.)
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- 2022
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36. Current Applications of Artificial Intelligence to Classify Cervical Lymph Nodes in Patients with Head and Neck Squamous Cell Carcinoma-A Systematic Review.
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Santer M, Kloppenburg M, Gottfried TM, Runge A, Schmutzhard J, Vorbach SM, Mangesius J, Riedl D, Mangesius S, Widmann G, Riechelmann H, Dejaco D, and Freysinger W
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Locally-advanced head and neck squamous cell carcinoma (HNSCC) is mainly defined by the presence of pathologic cervical lymph nodes (LNs) with or without extracapsular spread (ECS). Current radiologic criteria to classify LNs as non-pathologic, pathologic, or pathologic with ECS are primarily shape-based. However, significantly more quantitative information is contained within imaging modalities. This quantitative information could be exploited for classification of LNs in patients with locally-advanced HNSCC by means of artificial intelligence (AI). Currently, various reviews exploring the role of AI in HNSCC are available. However, reviews specifically addressing the current role of AI to classify LN in HNSCC-patients are sparse. The present work systematically reviews original articles that specifically explore the role of AI to classify LNs in locally-advanced HNSCC applying Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines and the Study Quality Assessment Tool of National Institute of Health (NIH). Between 2001 and 2022, out of 69 studies a total of 13 retrospective, mainly monocentric, studies were identified. The majority of the studies included patients with oropharyngeal and oral cavity (9 and 7 of 13 studies, respectively) HNSCC. Histopathologic findings were defined as reference in 9 of 13 studies. Machine learning was applied in 13 studies, 9 of them applying deep learning. The mean number of included patients was 75 (SD ± 72; range 10-258) and of LNs was 340 (SD ± 268; range 21-791). The mean diagnostic accuracy for the training sets was 86% (SD ± 14%; range: 43-99%) and for testing sets 86% (SD ± 5%; range 76-92%). Consequently, all of the identified studies concluded AI to be a potentially promising diagnostic support tool for LN-classification in HNSCC. However, adequately powered, prospective, and randomized control trials are urgently required to further assess AI's role in LN-classification in locally-advanced HNSCC.
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- 2022
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37. The Atherosclerosis Profile by Coronary Computed Tomography Angiography (CTA) in Symptomatic Patients with Coronary Artery Calcium Score Zero.
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Feuchtner G, Beyer C, Barbieri F, Spitaler P, Dichtl W, Friedrich G, Widmann G, and Plank F
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(1) Background: Whether it is safe to exclude coronary artery disease (CAD) in symptomatic patients with coronary artery calcium score (CACS 0), is an open debate. To compare coronary CTA including high-risk plaque (HRP) features in symptomatic patients with CACS 0 (2) Methods: 1709 symptomatic patients (age, mean 57.5 ± 16 years, 39.6% females) referred to coronary CTA for clinical indications were included. CACS, coronary stenosis (CADRADS) severity and HRP features (low-attenuation-plaque, spotty calcification, positive remodeling, NRS) were recorded. (3) Results: Of 1709 patients, 665 with CACS 0 were finally included. 562 (84.5%) had no CAD by CTA while 103 of 665 (15.4%) had CAD. Stenosis was minimal <25% in 79, mild <50% in 20, moderate in 1 and severe >70% in 3 patients. The rate of obstructive CAD was low with 4/665 (0.61%). The majority of patients had non-obstructive CAD (<50% stenosis) (99/103; 96.1%). A high proportion of patients with non-obstructive CAD had at least one HRP (52/103; 50.4%) per patient. (4) Conclusions: The rate of obstructive CAD is very low in symptomatic patients with CACS 0, and non-obstructive CAD domineering. CACS 0 does not rule out non-obstructive CAD and misses patients in which primary preventive measures are indicated. More than half of patients with non-obstructive CAD had high-risk plaque, highlighting the importance of quantitative plaque analysis.
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- 2022
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38. Chest CT of Lung Injury 1 Year after COVID-19 Pneumonia: The CovILD Study.
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Luger AK, Sonnweber T, Gruber L, Schwabl C, Cima K, Tymoszuk P, Gerstner AK, Pizzini A, Sahanic S, Boehm A, Coen M, Strolz CJ, Wöll E, Weiss G, Kirchmair R, Feuchtner GM, Prosch H, Tancevski I, Löffler-Ragg J, and Widmann G
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- Female, Humans, Lung diagnostic imaging, Male, Middle Aged, Prospective Studies, SARS-CoV-2, Tomography, X-Ray Computed methods, COVID-19 diagnostic imaging, Lung Injury
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Background The long-term pulmonary sequelae of COVID-19 is not well known. Purpose To characterize patterns and rates of improvement of chest CT abnormalities 1 year after COVID-19 pneumonia. Materials and Methods This was a secondary analysis of a prospective, multicenter observational cohort study conducted from April 29 to August 12, 2020, to assess pulmonary abnormalities at chest CT approximately 2, 3, and 6 months and 1 year after onset of COVID-19 symptoms. Pulmonary findings were graded for each lung lobe using a qualitative CT severity score (CTSS) ranging from 0 (normal) to 25 (all lobes involved). The association of demographic and clinical factors with CT abnormalities after 1 year was assessed with logistic regression. The rate of change of the CTSS at follow-up CT was investigated by using the Friedmann test. Results Of 142 enrolled participants, 91 underwent a 1-year follow-up CT examination and were included in the analysis (mean age, 59 years ± 13 [SD]; 35 women [38%]). In 49 of 91 (54%) participants, CT abnormalities were observed: 31 of 91 (34%) participants showed subtle subpleural reticulation, ground-glass opacities, or both, and 18 of 91 (20%) participants had extensive ground-glass opacities, reticulations, bronchial dilation, microcystic changes, or a combination thereof. At multivariable analysis, age of more than 60 years (odds ratio [OR], 5.8; 95% CI: 1.7, 24; P = .009), critical COVID-19 severity (OR, 29; 95% CI: 4.8, 280; P < .001), and male sex (OR, 8.9; 95% CI: 2.6, 36; P < .001) were associated with persistent CT abnormalities at 1-year follow-up. Reduction of CTSS was observed in participants at subsequent follow-up CT ( P < .001); during the study period, 49% (69 of 142) of participants had complete resolution of CT abnormalities. Thirty-one of 49 (63%) participants with CT abnormalities showed no further improvement after 6 months. Conclusion Long-term CT abnormalities were common 1 year after COVID-19 pneumonia. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Leung in this issue.
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- 2022
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39. Cardiac Computed Tomography: State of the Art and Future Horizons.
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Feuchtner GM, Plank F, Beyer C, Barbieri F, Widmann G, Spitaler P, and Dichtl W
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Cardiac computed tomography (CT) has evolved over the past 20 years from an alternative, promising noninvasive imaging modality to a Class I indication for the non-invasive evaluation of patients with low-to-intermediate, pre-test probability of coronary artery disease (CAD), as per the European Society of Cardiology (ESC) guidelines published in 2019 [...].
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- 2022
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40. The Impact of Iron Dyshomeostasis and Anaemia on Long-Term Pulmonary Recovery and Persisting Symptom Burden after COVID-19: A Prospective Observational Cohort Study.
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Sonnweber T, Grubwieser P, Sahanic S, Böhm AK, Pizzini A, Luger A, Schwabl C, Koppelstätter S, Kurz K, Puchner B, Sperner-Unterweger B, Hüfner K, Wöll E, Nairz M, Widmann G, Tancevski I, Löffler-Ragg J, and Weiss G
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Coronavirus disease 2019 (COVID-19) is frequently associated with iron dyshomeostasis. The latter is related to acute disease severity and COVID-19 convalescence. We herein describe iron dyshomeostasis at COVID-19 follow-up and its association with long-term pulmonary and symptomatic recovery. The prospective, multicentre, observational cohort study "Development of Interstitial Lung Disease (ILD) in Patients With Severe SARS-CoV-2 Infection (CovILD)" encompasses serial extensive clinical, laboratory, functional and imaging evaluations at 60, 100, 180 and 360 days after COVID-19 onset. We included 108 individuals with mild-to-critical acute COVID-19, whereas 75% presented with severe acute disease. At 60 days post-COVID-19 follow-up, hyperferritinaemia (35% of patients), iron deficiency (24% of the cohort) and anaemia (9% of the patients) were frequently found. Anaemia of inflammation (AI) was the predominant feature at early post-acute follow-up, whereas the anaemia phenotype shifted towards iron deficiency anaemia (IDA) and combinations of IDA and AI until the 360 days follow-up. The prevalence of anaemia significantly decreased over time, but iron dyshomeostasis remained a frequent finding throughout the study. Neither iron dyshomeostasis nor anaemia were related to persisting structural lung impairment, but both were associated with impaired stress resilience at long-term COVID-19 follow-up. To conclude, iron dyshomeostasis and anaemia are frequent findings after COVID-19 and may contribute to its long-term symptomatic outcome.
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- 2022
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41. Frequency and Consequences of Cervical Lymph Node Overstaging in Head and Neck Carcinoma.
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Schartinger VH, Dejaco D, Fischer N, Lettenbichler-Haug A, Anegg M, Santer M, Schmutzhard J, Kofler B, Vorbach S, Widmann G, and Riechelmann H
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Clinical lymph node staging in head and neck carcinoma (HNC) is fraught with uncertainties. Established clinical algorithms are available for the problem of occult cervical metastases. Much less is known about clinical lymph node overstaging. We identified HNC patients clinically classified as lymph node positive (cN+), in whom surgical neck dissection (ND) specimens were histopathologically negative (pN0) and in addition the subgroup, in whom an originally planned postoperative radiotherapy (PORT) was omitted. We compared these patients with surgically treated patients with clinically and histopathologically negative neck (cN0/pN0), who had received selective ND. Using a fuzzy matching algorithm, we identified patients with closely similar patient and disease characteristics, who had received primary definitive radiotherapy (RT) with or without systemic therapy (RT ± ST). Of the 980 patients with HNC, 292 received a ND as part of primary treatment. In 128/292 patients with cN0 neck, ND was elective, and in 164 patients with clinically positive neck (cN+), ND was therapeutic. In 43/164 cN+ patients, ND was histopathologically negative (cN+/pN-). In 24 of these, initially planned PORT was omitted. Overall, survival did not differ from the cN0/pN0 and primary RT ± ST control groups. However, more RT ± ST patients had functional problems with nutrition ( p = 0.002). Based on these data, it can be estimated that lymph node overstaging is 26% (95% CI: 20% to 34%). In 15% (95% CI: 10% to 21%) of surgically treated cN+ HNC patients, treatment can be de-escalated without the affection of survival.
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- 2022
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42. Dimensions and forms of artefacts in 1.5 T and 3 T MRI caused by cochlear implants.
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Gottfried TM, Dejaco D, Fischer N, Innerhofer V, Chacko LJ, Widmann G, Kremser C, Riechelmann H, and Schmutzhard J
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- Artifacts, Humans, Magnetic Resonance Imaging methods, Retrospective Studies, Cochlear Implantation, Cochlear Implants
- Abstract
Cochlear implantation is a standard treatment option due to expanding indications. Cranial magnetic resonance imaging (cMRI) has become a widespread diagnostic tool. Therefore, an increased number of cochlear implant (CI) users are undergoing cMRI scans. This study aimed to investigate the issue of the CI magnet impacting MRI quality and artifacts. 1.5 T and 3 T MRI scans with 4 defined sequences (T2-TSE, T2-TIRM, T1-3D-MPRAGE, and TDI) were performed on a phantom with a CI (SYNCHRONY System by MED-EL Austria) in place. The resulting MRI artifacts were retrospectively compared to MRI artifacts observed in patients with a CI. All images were transferred to AMIRA and visualized by manual segmentation. Usable image quality was achieved in three sequences (T2-TSE, T2-TIRM and T1-mprage). Observed artifacts differed in shape and size depending on the sequence. Maximum diameters of signal void areas ranged from 58 × 108 × 98 mm to 127 × 123 × 153 mm. Image distortions were larger. MRI artifacts caused by the SYNCHRONY system are asymmetric with varying shape, depending on the sequence. The phantom artefacts are similar to those in CI users. Considering the observed asymmetry, the hypothesis of varying implantation locations resulting in varying positions of the signal void area needs to be further investigated., (© 2022. The Author(s).)
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- 2022
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43. Quantity of IgG response to SARS-CoV-2 spike glycoprotein predicts pulmonary recovery from COVID-19.
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Nairz M, Sahanic S, Pizzini A, Böhm A, Tymoszuk P, Mitterstiller AM, von Raffay L, Grubwieser P, Bellmann-Weiler R, Koppelstätter S, Schroll A, Haschka D, Zimmermann M, Blunder S, Trattnig K, Naschberger H, Klotz W, Theurl I, Petzer V, Gehrer C, Mindur JE, Luger A, Schwabl C, Widmann G, Weiss G, Löffler-Ragg J, Tancevski I, and Sonnweber T
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- COVID-19 pathology, Female, Humans, Male, Middle Aged, Patient Acuity, Prospective Studies, Respiratory Function Tests, Reverse Transcriptase Polymerase Chain Reaction, COVID-19 immunology, Immunoglobulin G immunology, Lung pathology, Spike Glycoprotein, Coronavirus immunology
- Abstract
The CovILD study is a prospective, multicenter, observational cohort study to systematically follow up patients after coronavirus disease-2019 (COVID-19). We extensively evaluated 145 COVID-19 patients at 3 follow-up visits scheduled for 60, 100, and 180 days after initial confirmed diagnosis based on typical symptoms and a positive reverse transcription-polymerase chain reaction (RT-PCR) for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). We employed comprehensive pulmonary function and laboratory tests, including serum concentrations of IgG against the viral spike (S) glycoprotein, and compared the results to clinical data and chest computed tomography (CT). We found that at the 60 day follow-up, 131 of 145 (90.3%) participants displayed S-specific serum IgG levels above the cut-off threshold. Notably, the highly elevated IgG levels against S glycoprotein positively correlated with biomarkers of immune activation and negatively correlated with pulmonary function and the extent of pulmonary CT abnormalities. Based on the association between serum S glycoprotein-specific IgG and clinical outcome, we generated an S-specific IgG-based recovery score that, when applied in the early convalescent phase, accurately predicted delayed pulmonary recovery after COVID-19. Therefore, we propose that S-specific IgG levels serve as a useful immunological surrogate marker for identifying at-risk individuals with persistent pulmonary injury who may require intensive follow-up care after COVID-19., (© 2022. The Author(s).)
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- 2022
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44. Investigating phenotypes of pulmonary COVID-19 recovery: A longitudinal observational prospective multicenter trial.
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Sonnweber T, Tymoszuk P, Sahanic S, Boehm A, Pizzini A, Luger A, Schwabl C, Nairz M, Grubwieser P, Kurz K, Koppelstätter S, Aichner M, Puchner B, Egger A, Hoermann G, Wöll E, Weiss G, Widmann G, Tancevski I, and Löffler-Ragg J
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- Adult, Aged, COVID-19 epidemiology, COVID-19 rehabilitation, Female, Follow-Up Studies, Humans, Intensive Care Units, Logistic Models, Longitudinal Studies, Lung Diseases diagnosis, Male, Middle Aged, Phenotype, Prospective Studies, Risk Factors, SARS-CoV-2, Tomography, X-Ray Computed methods, COVID-19 therapy, Lung Diseases epidemiology, Lung Diseases physiopathology
- Abstract
Background: The optimal procedures to prevent, identify, monitor, and treat long-term pulmonary sequelae of COVID-19 are elusive. Here, we characterized the kinetics of respiratory and symptom recovery following COVID-19., Methods: We conducted a longitudinal, multicenter observational study in ambulatory and hospitalized COVID-19 patients recruited in early 2020 (n = 145). Pulmonary computed tomography (CT) and lung function (LF) readouts, symptom prevalence, and clinical and laboratory parameters were collected during acute COVID-19 and at 60, 100, and 180 days follow-up visits. Recovery kinetics and risk factors were investigated by logistic regression. Classification of clinical features and participants was accomplished by unsupervised and semi-supervised multiparameter clustering and machine learning., Results: At the 6-month follow-up, 49% of participants reported persistent symptoms. The frequency of structural lung CT abnormalities ranged from 18% in the mild outpatient cases to 76% in the intensive care unit (ICU) convalescents. Prevalence of impaired LF ranged from 14% in the mild outpatient cases to 50% in the ICU survivors. Incomplete radiological lung recovery was associated with increased anti-S1/S2 antibody titer, IL-6, and CRP levels at the early follow-up. We demonstrated that the risk of perturbed pulmonary recovery could be robustly estimated at early follow-up by clustering and machine learning classifiers employing solely non-CT and non-LF parameters., Conclusions: The severity of acute COVID-19 and protracted systemic inflammation is strongly linked to persistent structural and functional lung abnormality. Automated screening of multiparameter health record data may assist in the prediction of incomplete pulmonary recovery and optimize COVID-19 follow-up management., Funding: The State of Tyrol (GZ 71934), Boehringer Ingelheim/Investigator initiated study (IIS 1199-0424)., Clinical Trial Number: ClinicalTrials.gov: NCT04416100., Competing Interests: TS, SS, AB, AP, AL, CS, MN, PG, KK, SK, MA, BP, AE, GH, EW, GW, GW, IT, JL No competing interests declared, PT owns his own business, Data Analytics as a Service Tirol, for which he performs freelance data science work. Has also received an honorarium for the study data management, curation and analysis and minor manuscript work. The author has no other competing interests to declare, (© 2022, Sonnweber et al.)
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- 2022
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45. Benchmarking Eliminative Radiomic Feature Selection for Head and Neck Lymph Node Classification.
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Bardosi ZR, Dejaco D, Santer M, Kloppenburg M, Mangesius S, Widmann G, Ganswindt U, Rumpold G, Riechelmann H, and Freysinger W
- Abstract
In head and neck squamous cell carcinoma (HNSCC) pathologic cervical lymph nodes (LN) remain important negative predictors. Current criteria for LN-classification in contrast-enhanced computed-tomography scans (contrast-CT) are shape-based; contrast-CT imagery allows extraction of additional quantitative data ("features"). The data-driven technique to extract, process, and analyze features from contrast-CTs is termed "radiomics". Extracted features from contrast-CTs at various levels are typically redundant and correlated. Current sets of features for LN-classification are too complex for clinical application. Effective eliminative feature selection (EFS) is a crucial preprocessing step to reduce the complexity of sets identified. We aimed at exploring EFS-algorithms for their potential to identify sets of features, which were as small as feasible and yet retained as much accuracy as possible for LN-classification. In this retrospective cohort-study, which adhered to the STROBE guidelines, in total 252 LNs were classified as "non-pathologic" ( n = 70), "pathologic" ( n = 182) or "pathologic with extracapsular spread" ( n = 52) by two experienced head-and-neck radiologists based on established criteria which served as a reference. The combination of sparse discriminant analysis and genetic optimization retained up to 90% of the classification accuracy with only 10% of the original numbers of features. From a clinical perspective, the selected features appeared plausible and potentially capable of correctly classifying LNs. Both the identified EFS-algorithm and the identified features need further exploration to assess their potential to prospectively classify LNs in HNSCC.
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- 2022
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46. Technical efficacy and local recurrence after stereotactic radiofrequency ablation of 2653 liver tumors: a 15-year single-center experience with evaluation of prognostic factors.
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Schullian P, Laimer G, Johnston E, Putzer D, Eberle G, Scharll Y, Widmann G, Kolbitsch C, and Bale R
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- Aged, Humans, Neoplasm Recurrence, Local surgery, Prognosis, Retrospective Studies, Treatment Outcome, Carcinoma, Hepatocellular surgery, Catheter Ablation methods, Liver Neoplasms pathology, Radiofrequency Ablation methods
- Abstract
Purpose: To assess the technical outcome and local tumor control of multi-probe stereotactic radiofrequency ablation (SRFA) in a large series of patients. Furthermore, to determine factors accounting for adverse outcomes., Material and Methods: Between 2003 and 2018, 865 patients were treated by SRFA for 2653 primary and metastatic liver tumors with a median tumor size of 2.0 cm (0.5 - 19 cm). Primary technical efficacy (PTE) and local recurrence (LR) were evaluated, and possible predictors for adverse events analyzed using uni- and multi-variable binary logistic regression., Results: Overall, 2553 of 2653 tumors were successfully ablated at initial SRFA resulting in a PTE rate of 96.2%. Predictors of lower PTE rates were age > 70 years, tumor size > 5 cm, number of probes, location close to liver capsule/organs and segment II. LR occurred in 220 of 2653 tumors (8.3%) with the following predictors: age, tumor type/size, conglomerates, segments I/IVa/IVb, number of probes and location close to major vessels/bile duct. Multivariable analysis revealed tumor size > 5 cm (odds ratio [OR] 3.153), age > 70 years (OR 1.559), and location in segment II (OR 1.772) as independent prognostic factors for PTE, whereas tumor location close to major vessels (OR 1.653) and in segment IVb (OR 2.656) were identified as independent prognostic factors of LR., Conclusions: Stereotactic RFA is an attractive option in the management of primary or metastatic liver tumors with good local tumor control, even in large tumors. The presented prognostic factors for adverse local oncological outcome might help to stratify unfavorable tumors for ablation.
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- 2022
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47. The Atherosclerotic Profile of a Young Symptomatic Population between 19 and 49 Years: Coronary Computed Tomography Angiography or Coronary Artery Calcium Score?
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Feuchtner GM, Beyer C, Langer C, Bleckwenn S, Senoner T, Barbieri F, Luger A, Spitaler P, Widmann G, Adukauskaite A, Dichtl W, Friedrich G, and Plank F
- Abstract
(1) Background: Whether coronary computed tomography angiography (CTA) or the coronary artery calcium score (CACS) should be used for diagnosis of coronary heart disease, is an open debate. The aim of our study was to compare the atherosclerotic profile by coronary CTA in a young symptomatic high-risk population (age, 19-49 years) in comparison with the coronary artery calcium score (CACS). (2) Methods: 1137 symptomatic high-risk patients between 19-49 years (mean age, 42.4 y) who underwent coronary CTA and CACS were stratified into six age groups. CTA-analysis included stenosis severity and high-risk-plaque criteria (3) Results: Atherosclerosis was more often detected based on CTA than based on CACS (45 vs. 27%; p < 0.001), 50% stenosis in 13.6% and high-risk plaque in 17.7%. Prevalence of atherosclerosis was low and not different between CACS and CTA in the youngest age groups (19-30 y: 5.2 and 6.4% and 30-35 y: 10.6 and 16%). In patients older than >35 years, the rate of atherosclerosis based on CTA increased ( p = 0.004, OR: 2.8, 95%CI:1.45-5.89); and was higher by CTA as compared to CACS (34.9 vs. 16.7%; p < 0.001), with a superior performance of CTA. In patients older than 35 years, stenosis severity ( p = 0.002) and >50% stenosis increased from 2.6 to 12.5% ( p < 0.001). High-risk plaque prevalence increased from 6.4 to 26.5%. The distribution of high-risk plaque between CACS 0 and >0.1 AU was similar among all age groups, with an increasing proportion in CACS > 0.1 AU with age. A total of 24.9% of CACS 0 patients had coronary artery disease based on CTA, 4.4% > 50% stenosis and 11.5% had high-risk plaque. (4) Conclusions: In a symptomatic young high-risk population older than 35 years, CTA performed superior than CACS. In patients aged 19-35 years, the rate of atherosclerosis was similar and low based on both modalities. CACS 0 did not rule out coronary artery disease in a young high-risk population.
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- 2021
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48. Coronary Artery Dimensions in Endurance Athletes by Computed Tomography Angiography: A Quantitative Analysis.
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Langer C, Barbieri F, Plank F, Beyer C, Baldauf B, Friedrich G, Widmann G, Luger A, Adukauskaite A, Reinthaler M, Dichtl W, Homma S, and Feuchtner GM
- Abstract
(1) Background: The athlete's heart may develop permanent vessel enlargement. The purpose of our study was to define normal values for coronary artery dimensions of endurance athletes by coronary computed tomography angiography (CTA). (2) Methods: Ninety-eight individuals (56.2 ± 11 years) were included into this retrospective matched case-controlled-study. Endurance athletes had regular training volumes of ≥1 h per unit, ≥3-7 times per week (either cycling, running or mountain-endurance). Athletes were matched for age and gender with sedentary controls using propensity score. Quantitative CTA analysis included coronary vessel dimensions (two diameters and area) of the LM, LAD, CX and RCA for all AHA-16-segments. (3) Results: Proximal LAD area and diameter ( p = 0.019); proximal/mid CX (diameter and area; p = 0.026 and p = 0.018/ p = 0.008 and p = 0.009); mid RCA diameter and area; and proximal RCA diameter were significantly larger in endurance athletes ( p < 0.05). The left main area ( p = 0.708) and diameter ( p = 0.809) as well as the mid LAD and distal segments were not different. We present the histograms and data for normal values ±1 and ± 2 SD. (4) Conclusions: Endurance athletes have larger proximal LAD, proximal/mid CX and RCA vessel dimensions, while LM and distal segments are similar. Hence, dilated coronary arteries in endurance athletes (" Athlete's arteries ") have to be distinguished from diffuse ectatic segments developing during Kawasaki disease or multisystemic inflammation syndrome after COVID-19.
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- 2021
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49. ALADA Dose Optimization in the Computed Tomography of the Temporal Bone: The Diagnostic Potential of Different Low-Dose CT Protocols.
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Kofler B, Jenetten L, Runge A, Degenhart G, Fischer N, Hörmann R, Steurer M, and Widmann G
- Abstract
Objective: Repeated computed tomography (CT) is essential for diagnosis, surgical planning and follow-up in patients with middle and inner ear pathology. Dose reduction to "as low as diagnostically acceptable" (ALADA) is preferable but challenging. We aimed to compare the diagnostic quality of images of subtle temporal bone structures produced with low doses (LD) and reference protocols (RP)., Methods: Two formalin-fixed human cadaver heads were scanned using a 64-slice CT scanner and cone-beam CT (CBCT). The protocols were: RP (120 kV, 250 mA, CTDIvol 83.72 mGy), LD1 (100 kV, 80 mA, CTDIvol 26.79 mGy), LD2 (100 kV, 35 mA, CTDIvol 7.66 mGy), LD3 (80 kV, 40 mA, CTDIvol 4.82 mGy), and CBCT standard protocol. Temporal bone structures were assessed using a 5-point scale., Results: A median score of ≥2 was achieved with protocols such as the tendons of m. tensor tympani (RP/LD1/LD2/CBCT) and m. stapedius (CBCT), the incudostapedial joint (RP/LD1/CBCT), the incudomalleolar joint (RP/LD1/LD2/CBCT), the stapes feet (RP/LD1/CBCT), the stapes head (RP/LD1/LD2/CBCT), the tympanic membrane (RP/LD1/LD2/CBCT), the lamina spiralis ossea (none), the chorda tympani (RP/LD1/CBCT), and the modiolus (RP/LD1/LD2/CBCT). Adaptive statistical iterative reconstructions did not show advantages over the filtered back projection., Conclusions: LD protocols using a CTDIvol of 7.66 mGy may be sufficient for the identification of temporal bone structures.
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- 2021
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50. The Effect of Vitamin D on Coronary Atherosclerosis: A Propensity Score Matched Case-Control Coronary CTA Study.
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Feuchtner G, Suppersberger S, Langer C, Beyer C, Rauch S, Thurner T, Friedrich G, Dichtl W, Widmann G, Plank F, and Barbieri F
- Abstract
Background: Vitamin D supplementation may be associated with lower cardiovascular (CV) events, but the data are controversial. It remains speculative whether vitamin D supplementation has a direct effect on coronary atherosclerosis. We therefore set out to assess the influence of vitamin D supplementation on the coronary atherosclerosis profile quantified by coronary computed tomography angiography (CTA) in a retrospective case-control cohort study., Methods: 176 patients (age: 62.4 ± 10.4) referred to coronary CTA for clinical indications were included. A total of 88 patients receiving vitamin D supplementation (mean duration 65.3 ± 81 months) were 1:1 propensity score matched with 88 controls for age, gender, smoking, arterial hypertension, positive family history, dyslipidemia, and diabetes. Coronary stenosis severity (CAD-RADS
TM ), mixed plaque burden (weighted for non-calcified), high-risk-plaque (HRP) features, and plaque density (HU) were quantified by CTA. Serum 25-hydroxyvitamin D (OH)-levels were measured in 138 patients and categorized into four groups (0: <20 ng/mL; 1: 20-40 ng/mL; 2: 40-60 ng/mL; and 3: >60 ng/mL) and compared with CTA., Results: The prevalence of atherosclerosis by CTA was similar in both groups (75.6% versus 74.3%, p = 0.999), >50% coronary stenosis was slightly higher in controls ( p = 0.046), but stenosis severity score (CAD-RADS) was not different ( p = 0.106). Mixed plaque burden (weighted for non-calcified) was lower in patients receiving vitamin D supplementation ( p = 0.002) and high-risk-plaque prevalence was markedly lower (3.8% versus 32%, p < 0.001). CT plaque density (HU) was higher ( p < 0.001) in the vitamin D group. Patients with serum vitamin D (OH) levels >60 ng/mL had higher plaque density ( p = 0.04), indicating more calcified and less vulnerable plaque., Conclusions: In this retrospective case-control cohort study, vitamin D supplementation was associated with less high-risk plaque, less non-calcified plaque burden, and a higher calcified plaque independent of CV risk factors.- Published
- 2021
- Full Text
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