Publications by authors named "Christoph Mader"

Article Synopsis
  • The study investigates the use of Large Language Models (LLMs), specifically ChatGPT, in medical education, focusing on their ability to enhance the learning experience for medical students.
  • Using 151 radiology exam questions, the performance of OpenAI's GPT-3.5 and GPT-4 was assessed, with GPT-4 showing significantly higher accuracy (88.1%) compared to GPT-3.5 (67.6%).
  • Results suggest that LLMs, especially GPT-4, could serve as effective study resources for medical students preparing for exams, although users should be cautious of potential inaccuracies in responses.
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Intussusception in adult patients is a rare medical finding, which is accompanied by an underlying tumor in some cases. However, no accepted method has been established to identify patients at risk for tumor-related intussusception. This study aimed to identify imaging features as predictors for tumor-related intussusception.

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Introduction:  Prethrombin-1 is a Gla-domain lacking enzymatically inactive split product that results from the cleavage of fragment 1 from prothrombin by thrombin in a feedback reaction.

Methods:  A prethrombin-1 preparation derived from human plasma was tested for its hemostatic and thrombogenic properties. Animal models of nail clipping (for rabbits) and tail clipping (for mice) were developed to measure blood loss in FVIII-inhibitor or rivaroxaban anticoagulated rabbits and mice, respectively.

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Article Synopsis
  • Lumbar disk degeneration is a common cause of back pain, and this study aimed to assess the effectiveness of dual-energy CT (DECT)-derived collagen maps in evaluating its severity.
  • The research analyzed data from 127 patients who had both DECT and MRI scans, categorizing the level of disk degeneration using a scale and calculating the accuracy and sensitivity of DECT maps compared to MRI.
  • Results showed that DECT collagen maps had a high accuracy rate (85.5%) for diagnosing different stages of degeneration, suggesting their potential use in situations where MRI is not an option.
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Rationale And Objectives: Bone non-union is a serious complication of distal radius fractures (DRF) that can result in functional limitations and persistent pain. However, no accepted method has been established to identify patients at risk of developing bone non-union yet. This study aimed to compare various CT-derived metrics for bone mineral density (BMD) assessment to identify predictive values for the development of bone non-union.

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Article Synopsis
  • Cancer patients are at a higher risk for venous thromboembolism (VTE), but traditional D-dimer testing combined with clinical assessment may not be as effective in this group.
  • D-dimer levels can help rule out VTE, and if elevated beyond ten times the normal limit, may indicate a high probability of VTE with over 80% positive predictive value, while also providing prognostic information about cancer severity and potential outcomes.
  • There is a need for standardizing D-dimer testing protocols and creating tailored models for assessing cancer patients to improve diagnostic accuracy for VTE.
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Hepatocellular carcinoma (HCC) often arises in cirrhotic livers. Generally, decompensated liver cirrhosis is a contraindication to surgery. Even in compensated liver cirrhosis, liver resection for HCC carries a high risk of post-hepatectomy liver failure and decompensation of cirrhosis.

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Purpose: To identify transjugular intrahepatic portosystemic shunt (TIPS) thrombosis in abdominal CT scans applying quantitative image analysis.

Materials And Methods: We retrospectively screened 184 patients to include 20 patients (male, 8; female, 12; mean age, 60.7 ± 8.

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Clinical/methodical Issue: The diagnosis of hepatocellular carcinoma (HCC)-especially the characterization of small lesions <2 cm-continues to be a radiological challenge.

Standard Radiological Methods: In the current S3 guideline on diagnosis and therapy of HCC, contrast-enhanced imaging examinations, such as contrast-enhanced ultrasonography (CEUS), computed tomography (CT), and magnetic resonance imaging (MRI), are still the diagnostic standard.

Methodological Innovations: HCC in the cirrhotic liver should be diagnosed by its typical contrast-enhanced pattern in the MRI.

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Objectives: To investigate the diagnostic accuracy of color-coded contrast-enhanced dual-energy CT virtual noncalcium (VNCa) reconstructions for the assessment of lumbar disk herniation compared to unenhanced VNCa imaging.

Methods: A total of 91 patients were retrospectively evaluated (65 years ± 16; 43 women) who had undergone third-generation dual-source dual-energy CT and 3.0-T MRI within an examination interval up to 3 weeks between November 2019 and December 2020.

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Objectives: To evaluate the predictive value of volumetric bone mineral density (BMD) assessment of the lumbar spine derived from phantomless dual-energy CT (DECT)-based volumetric material decomposition as an indicator for the 2-year occurrence risk of osteoporosis-associated fractures.

Methods: L1 of 92 patients (46 men, 46 women; mean age, 64 years, range, 19-103 years) who had undergone third-generation dual-source DECT between 01/2016 and 12/2018 was retrospectively analyzed. For phantomless BMD assessment, dedicated DECT postprocessing software using material decomposition was applied.

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Background: Dual-source dual-energy computed tomography (DECT) offers the potential for opportunistic osteoporosis screening by enabling phantomless bone mineral density (BMD) quantification. This study sought to assess the accuracy and precision of volumetric BMD measurement using dual-source DECT in comparison to quantitative CT (QCT).

Methods: A validated spine phantom consisting of three lumbar vertebra equivalents with 50 (L1), 100 (L2), and 200 mg/cm (L3) calcium hydroxyapatite (HA) concentrations was scanned employing third-generation dual-source DECT and QCT.

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Purpose: To assess the influence of intravenously injected contrast agent on bone mineral density (BMD) assessment in dual-source dual-energy CT.

Methods: This retrospective study included 1,031 patients (mean age, 53 ± 7 years; 519 women) who had undergone third-generation dual-source dual-energy CT in context of tumor staging between January 2019 and December 2019. Dedicated postprocessing software based on material decomposition was used for phantomless volumetric BMD assessment of trabecular bone of the lumbar spine.

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Objectives: To determine the diagnostic accuracy of dual-energy CT (DECT) virtual noncalcium (VNCa) reconstructions for assessing thoracic disk herniation compared to standard grayscale CT.

Methods: In this retrospective study, 87 patients (1131 intervertebral disks; mean age, 66 years; 47 women) who underwent third-generation dual-source DECT and 3.0-T MRI within 3 weeks between November 2016 and April 2020 were included.

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Objectives: To evaluate the potential of a fully automatic artificial intelligence (AI)-driven computed tomography (CT) software prototype to quantify severity of COVID-19 infection on chest CT in relationship with clinical and laboratory data.

Methods: We retrospectively analyzed 50 patients with laboratory confirmed COVID-19 infection who had received chest CT between March and July 2020. Pulmonary opacifications were automatically evaluated by an AI-driven software and correlated with clinical and laboratory parameters using Spearman-Rho and linear regression analysis.

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Objectives: To investigate the diagnostic accuracy of color-coded dual-energy CT virtual non-calcium (VNCa) reconstructions for the assessment of bone marrow edema (BME) of the scaphoid in patients with acute wrist trauma.

Methods: Our retrospective study included data from 141 patients (67 women, 74 men; mean age 43 years, range 19-80 years) with acute wrist trauma who had undergone third-generation dual-source dual-energy CT and 3-T MRI within 7 days. Eight weeks after assessment of conventional grayscale dual-energy CT scans for the presence of fractures, corresponding color-coded VNCa reconstructions were independently analyzed by the same six radiologists for the presence of BME.

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Liver metastasis in colorectal cancer is common and the primary treatment is chemotherapy. To date, there is no routinely used test in clinical practice to predict the effectiveness of conventional chemotherapy. Therefore, biomarkers with predictive value for conventional chemotherapy would be of considerable benefit in treatment planning.

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The complete nucleotide sequence encoding the high-molecular-mass amylase (HMMA) of Geobacillus stearothermophilus ATCC 12980 was established by PCR techniques. Based on the hmma gene sequence, the full-length rHMMA, four N- or C-terminal rHMMA truncations as well as three C-terminal rHMMA fragments were cloned and heterologously expressed in Escherichia coli. Purified rHMMA forms were used either for affinity studies with the recombinant (r) S-layer protein SbsC (rSbsC), peptidoglycan-containing sacculi (PGS) and pure peptidoglycan (PG) devoid of the secondary cell wall polymer (SCWP), or for surface plasmon resonance (SPR) studies using rSbsC and isolated SCWP.

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The secondary cell wall polymer (SCWP) from Geobacillus stearothermophilus PV72/p2, which is involved in the anchoring of the surface-layer protein to the bacterial cell wall layer, is composed of 2-amino-2-deoxy- and 2-acetamido-2-deoxy-D-glucose, 2-acetamido-2-deoxy-D-mannose, and 2-acetamido-2-deoxy-D-mannuronic acid. The primary structure of the acid-degraded polysaccharide--liberated by HF-treatment from the cell wall--was determined by high-field NMR spectroscopy and mass spectrometry using N-acetylated and hydrolyzed polysaccharide derivatives as well as Smith-degradation. The polysaccharide was shown to consist of a tetrasaccharide repeating unit containing a pyruvic acid acetal at a side-chain 2-acetamido-2-deoxy-alpha-D-mannopyranosyl residue.

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Alternative approaches for the determination of band broadening in size-exclusion chromatography based on the use of exponentially modified Gaussian (EMG) functions were used to experimentally investigate the performance of two different column sets. In both cases, the columns were combined in order to cover the complete fractionation range (from 10(3) to 5x10(6) g mol(-1)), which is of interest in many applications. When analyzing experimental chromatograms the question of proper data treatment (especially the necessary smoothing routines) became obvious and is discussed accordingly.

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Surface plasmon resonance studies using C-terminal truncation forms of the S-layer protein SbsC (recombinant SbsC consisting of amino acids 31 to 270 [rSbsC(31-270)] and rSbsC(31-443)) and the secondary cell wall polymer (SCWP) isolated from Geobacillus stearothermophilus ATCC 12980 confirmed the exclusive responsibility of the N-terminal region comprising amino acids 31 to 270 for SCWP binding. Quantitative analyses indicated binding behavior demonstrating low, medium, and high affinities.

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A number of polystyrene samples and standards were measured with several column combinations which differed in their extent of band broadening, sigma(BB). Comparison of the derived chain length distributions showed in some cases good agreement even despite strong distinctions in the determined sigma(BB) values. The calculated number and weight averages of the samples were almost identical in most cases for the column combinations used.

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The interaction between S-layer protein SbsB and the secondary cell wall polymer (SCWP) of Geobacillus stearothermophilus PV72/p2 was investigated by real-time surface plasmon resonance biosensor technology. The SCWP is an acidic polysaccharide that contains N-acetylglucosamine, N-acetylmannosamine, and pyruvic acid. For interaction studies, recombinant SbsB (rSbsB) and two truncated forms consisting of either the S-layer-like homology (SLH) domain (3SLH) or the residual part of SbsB were used.

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