Vitali Koch

Dr. Vitali Koch

orcid

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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19 June 2023 in Diagnostics
Verified
Journal Article
Open access
PDF file
LALeona Soraja Alizadeh
Leona Soraja Alizadeh
Thomas Josef VoglThomas Josef Vogl
Thomas Josef Vogl
SWStephan Waldeck
Stephan Waldeck
DODaniel Overhoff
Daniel Overhoff
TDTommaso D'Angelo
Tommaso D'Angelo
CBChristian Booz
Christian Booz
This article describes the technical principles and clinical applications of dual-energy computed tomography (DECT) in the context of cardiothoracic imaging with a focus on current developments and techniques. Since the introduction of DECT, different vendors developed distinct hard and software approaches for generating multi-energy datasets and multiple DECT applications that were developed and clinically investigated for different fields of interest. Benefits for various clinical settings, such as oncology, trauma and emergency radiology, as well as musculoskeletal and cardiovascular imaging, were recently reported in the literature. State-of-the-art applications, such as virtual monoenergetic imaging (VMI), material decomposition, perfused blood volume imaging, virtual non-contrast imaging (VNC), plaque removal, and virtual non-calcium (VNCa) imaging, can significantly improve cardiothoracic CT image workflows and have a high potential for improvement of diagnostic accuracy and patient safety.

6 July 2023 in European Journal of Clinical Investigation
Verified
Journal Article
Open access
JGJennifer Gotta
Jennifer Gotta
LGLeon D. Gruenewald
Leon D. Gruenewald
KEKatrin Eichler
Katrin Eichler
SMSimon S. Martin
Simon S. Martin
SMScherwin Mahmoudi
Scherwin Mahmoudi
VKVitali Koch
Vitali Koch
Background: Cancer is a well‐known risk factor for venous thromboembolism (VTE). A combined strategy of D‐dimer testing and clinical pre‐test probability is usually used to exclude VTE. However, its effectiveness is diminished in cancer patients due to reduced specificity, ultimately leading to a decreased clinical utility. This review article seeks to provide a comprehensive summary of how to interpret D‐dimer testing in cancer patients.Methods: In accordance with PRISMA standards, literature pertaining to the diagnostic and prognostic significance of D‐dimer testing in cancer patients was carefully chosen from reputable sources such as PubMed and the Cochrane databases.Results: D‐dimers have not only a diagnostic value in ruling out VTE but can also serve as an aid for rule‐in if their values exceed 10‐times the upper limit of normal. This threshold allows a diagnosis of VTE in cancer patients with a positive predictive value of more than 80%. Moreover, elevated D‐dimers carry important prognostic information and are associated with VTE reoccurrence. A gradual increase in risk for all‐cause death suggests that VTE is also an indicator of biologically more aggressive cancer types and advanced cancer stages. Considering the lack of standardization for D‐dimer assays, it is essential for clinicians to carefully consider the variations in assay performance and the specific test characteristics of their institution.Conclusions: Standardizing D‐dimer assays and developing modified pretest probability models specifically for cancer patients, along with adjusted cut‐off values for D‐dimer testing, could significantly enhance the accuracy and effectiveness of VTE diagnosis in this population.

14 August 2023 in Diagnostics
Verified
Journal Article
Open access
PDF file
TDTommaso D'Angelo
Tommaso D'Angelo
LLLudovica Rosa Maria Lanzafame
Ludovica Rosa Maria Lanzafame
AMAntonino Micari
Antonino Micari
ABAlfredo Blandino
Alfredo Blandino
IYIbrahim Yel
Ibrahim Yel
SMSilvio Mazziotti
Silvio Mazziotti
Background: To evaluate if coronary CT angiography (CCTA) monoenergetic reconstructions, obtained with a dual-layer spectral detector computed tomography (DLCT) system, offer improved image quality compared with 120 kVp conventional images without affecting the quantitative assessment of coronary stenoses. Methods: Fifty CCTA datasets (30 men; mean age: 61.6 ± 12.3 years) acquired with a DLCT system were reconstructed using virtual monoenergetic images (VMI) from 40 to 100 keV with 10 keV increment and compared with conventional images. An analysis of objective image quality was performed, evaluating the signal- and contrast-to-noise ratio. For the subjective assessment, two readers used a 5-point Likert scoring system to evaluate sharpness, noise, demarcation of coronary plaques, vascular contrast, and an overall score. Furthermore, coronary stenoses were analyzed for each vessel to describe the diagnostic agreement between monoenergetic images and conventional images. Results: The objective image analysis showed that all reconstructions from 70 keV to 40 keV show higher SNR (from 61.33 ± 12.46 to 154.22 ± 42.91, respectively) and CNR (from 51.45 ± 11.19 to 135.63 ± 39.38, respectively) compared with conventional images (all p < 0.001). The 40 keV monoenergetic images obtained the best average score for sharpness, vascular contrast, and for the overall impression (all with p < 0.001). The detection and grading of stenoses of the coronary arteries with conventional and monoenergetic images at 70 keV and 40 keV showed an overall excellent interobserver agreement (k= 0.81 [0.72–0.91]). Conclusions: The 40 keV virtual monoenergetic images obtained with a DLCT system allow the objective and subjective image quality of coronary CT angiography to be improved.

18 April 2023 in Cancer Imaging
Verified
Journal Article
Open access
PDF file
VKVitali Koch
Vitali Koch
NWNils Weitzer
Nils Weitzer
DSDaniel Pinto Dos Santos
Daniel Pinto Dos Santos
LGLeon D. Gruenewald
Leon D. Gruenewald
SMScherwin Mahmoudi
Scherwin Mahmoudi
MAMoritz H. Albrecht
Moritz H. Albrecht
Background: The advent of next-generation computed tomography (CT)- and magnetic resonance imaging (MRI) opened many new perspectives in the evaluation of tumor characteristics. An increasing body of evidence suggests the incorporation of quantitative imaging biomarkers into clinical decision-making to provide mineable tissue information. The present study sought to evaluate the diagnostic and predictive value of a multiparametric approach involving radiomics texture analysis, dual-energy CT-derived iodine concentration (DECT-IC), and diffusion-weighted MRI (DWI) in participants with histologically proven pancreatic cancer. Methods: In this study, a total of 143 participants (63 years ± 13, 48 females) who underwent third-generation dual-source DECT and DWI between November 2014 and October 2022 were included. Among these, 83 received a final diagnosis of pancreatic cancer, 20 had pancreatitis, and 40 had no evidence of pancreatic pathologies. Data comparisons were performed using chi-square statistic tests, one-way ANOVA, or two-tailed Student’s t-test. For the assessment of the association of texture features with overall survival, receiver operating characteristics analysis and Cox regression tests were used. Results: Malignant pancreatic tissue differed significantly from normal or inflamed tissue regarding radiomics features (overall P < .001, respectively) and iodine uptake (overall P < .001, respectively). The performance for the distinction of malignant from normal or inflamed pancreatic tissue ranged between an AUC of ≥ 0.995 (95% CI, 0.955–1.0; P < .001) for radiomics features, ≥ 0.852 (95% CI, 0.767–0.914; P < .001) for DECT-IC, and ≥ 0.690 (95% CI, 0.587–0.780; P = .01) for DWI, respectively. During a follow-up of 14 ± 12 months (range, 10–44 months), the multiparametric approach showed a moderate prognostic power to predict all-cause mortality (c-index = 0.778 [95% CI, 0.697–0.864], P = .01). Conclusions: Our reported multiparametric approach allowed for accurate discrimination of pancreatic cancer and revealed great potential to provide independent prognostic information on all-cause mortality.

10 July 2022 in Diagnostics
Verified
Journal Article
Open access
PDF file
SMSimon S. Martin
Simon S. Martin
JKJetlir Kolaneci
Jetlir Kolaneci
RCRouben Czwikla
Rouben Czwikla
CBChristian Booz
Christian Booz
LGLeon David Gruenewald
Leon David Gruenewald
VKVitali Koch
Vitali Koch
Purpose: To investigate the diagnostic performance of noise-optimized virtual monoenergetic images (VMI+) in dual-energy CT (DECT) of portal vein thrombosis (PVT) compared to standard reconstructions. Method: This retrospective, single-center study included 107 patients (68 men; mean age, 60.1 ± 10.7 years) with malignant or cirrhotic liver disease and suspected PVT who had undergone contrast-enhanced portal-phase DECT of the abdomen. Linearly blended (M_0.6) and virtual monoenergetic images were calculated using both standard VMI and noise-optimized VMI+ algorithms in 20 keV increments from 40 to 100 keV. Quantitative measurements were performed in the portal vein for objective contrast-to-noise ratio (CNR) calculation. The image series showing the greatest CNR were further assessed for subjective image quality and diagnostic accuracy of PVT detection by two blinded radiologists. Results: PVT was present in 38 subjects. VMI+ reconstructions at 40 keV revealed the best objective image quality (CNR, 9.6 ± 4.3) compared to all other image reconstructions (p < 0.01). In the standard VMI series, CNR peaked at 60 keV (CNR, 4.7 ± 2.1). Qualitative image parameters showed the highest image quality rating scores for the 60 keV VMI+ series (median, 4) (p ≤ 0.03). The greatest diagnostic accuracy for the diagnosis of PVT was found for the 40 keV VMI+ series (sensitivity, 96%; specificity, 96%) compared to M_0.6 images (sensitivity, 87%; specificity, 92%), 60 keV VMI (sensitivity, 87%; specificity, 97%), and 60 keV VMI+ reconstructions (sensitivity, 92%; specificity, 97%) (p ≤ 0.01). Conclusions: Low-keV VMI+ reconstructions resulted in significantly improved diagnostic performance for the detection of PVT compared to other DECT reconstruction algorithms.

29 December 2022 in Fundamental & Clinical Pharmacology
Verified
Journal Article
Open access
VKVitali Koch
Vitali Koch
LGLeon D. Gruenewald
Leon D. Gruenewald
TGTatjana Gruber‐Rouh
Tatjana Gruber‐Rouh
KEKatrin Eichler
Katrin Eichler
DLDavid M. Leistner
David M. Leistner
SMSimon S. Martin
Simon S. Martin
Upcoming experimental and epidemiological data have identified the endogenous non‐proteinogenic amino acid L‐homoarginine (L‐hArg) not only as a novel biomarker for cardiovascular disease but also as being directly involved in the pathogenesis of cardiac dysfunction. The association of low L‐hArg levels with adverse cardiovascular events and mortality has proposed the idea of nutritional supplementation to rescue pathways inversely associated with cardiovascular health. Subsequent clinical and experimental studies contributed significantly to our knowledge of potential effects on the cardiorenal axis, acting either as a biomarker or a cardiovascular active agent. In this review article, we provide a comprehensive summary of the L‐hArg metabolism, pathophysiological aspects, and current developments in the field of experimental and clinical evidence in favor of protective cardiovascular effects. Establishing a reliable biomarker to identify patients at high risk to die of cardiovascular disease represents one of the main goals for tackling this disease and providing individual therapeutic guidance.