In vitro and in vivo optimized reconstruction for low-keV virtual monoenergetic photon-counting detector CT angiography of lower legs.

Background: Lower extremity peripheral artery disease frequently presents with calcifications which reduces the accuracy of computed tomography (CT) angiography, especially below-the-knee. Photon-counting detector (PCD)-CT offers improved spatial resolution and less calcium blooming. We aimed to identify the optimal reconstruction parameters for PCD-CT angiography of the lower legs.

Structured reporting for efficient epidemiological and in-hospital prevalence analysis of pulmonary embolisms.

Structured reporting (SR) not only offers advantages regarding report quality but, as an IT-based method, also the opportunity to aggregate and analyze large, highly structured datasets (data mining). In this study, a data mining algorithm was used to calculate epidemiological data and in-hospital prevalence statistics of pulmonary embolism (PE) by analyzing structured CT reports.All structured reports for PE CT scans from the last 5 years (n = 2790) were extracted from the SR database and analyzed.

Ultra-high resolution coronary CT angiography on photon-counting detector CT: bi-centre study on the impact of quantum iterative reconstruction on image quality and accuracy of stenosis measurements.

Purpose: To assess the impact of different quantum iterative reconstruction (QIR) levels on objective and subjective image quality of ultra-high resolution (UHR) coronary CT angiography (CCTA) images and to determine the effect of strength levels on stenosis quantification using photon-counting detector (PCD)-CT.

Method: A dynamic vessel phantom containing two calcified lesions (25 % and 50 % stenosis) was scanned at heart rates of 60, 80 and 100 beats per minute with a PCD-CT system. In vivo CCTA examinations were performed in 102 patients.

Value of vendor-agnostic deep learning image denoising in brain computed tomography: A multi-scanner study.

To evaluate the effect of a vendor-agnostic deep learning denoising (DLD) algorithm on diagnostic image quality of non-contrast cranial computed tomography (ncCT) across five CT scanners.This retrospective single-center study included ncCT data of 150 consecutive patients (30 for each of the five scanners) who had undergone routine imaging after minor head trauma. The images were reconstructed using filtered back projection (FBP) and a vendor-agnostic DLD method.

Ultrahigh-Spatial-Resolution Photon-counting Detector CT Angiography of Coronary Artery Disease for Stenosis Assessment.

Background Coronary CT angiography is a first-line test in coronary artery disease but is limited by severe calcifications. Photon-counting-detector (PCD) CT improves spatial resolution. Purpose To investigate the effect of improved spatial resolution on coronary stenosis assessment and reclassification.

A multidisciplinary pulmonary embolism response team (PERT): first experience from a single center in Germany.

Background: Over the last few years, the concept of multidisciplinary pulmonary embolism response teams (PERTs) has emerged to encounter the increasing variety and complexity in managing acute pulmonary embolism (PE).

Purpose: To investigate PERT's composition and added clinical value in a university center in Germany.

Methods: Over 4 years (01/2019-11/2022), patients with confirmed PE were enrolled in a prospective single-center cohort study (PERT Mainz).

Late-Onset Prosthetic Endocarditis with Paraaortic Abscess Caused by .

, an integral component of the skin's customary bacterial flora, represents a Gram-positive anaerobic bacterium characterized by its low virulence. Despite its low virulence, the pathogen can cause profound-seated infections as well as infections linked to medical devices. We report a case study of a prosthesis endocarditis accompanied by a paraaortic abscess caused by , a development occurring five years prior to composite aortic root and valve replacement.

Quantum iterative reconstruction on a photon-counting detector CT improves the quality of hepatocellular carcinoma imaging.

Background: Excellent image quality is crucial for workup of hepatocellular carcinoma (HCC) in patients with liver cirrhosis because a signature tumor signal allows for non-invasive diagnosis without histologic proof. Photon-counting detector computed tomography (PCD-CT) can enhance abdominal image quality, especially in combination with a novel iterative reconstruction algorithm, quantum iterative reconstruction (QIR). The purpose of this study was to analyze the impact of different QIR levels on PCD-CT imaging of HCC in both phantom and patient scans.

Optimization of Kernel Type and Sharpness Level Improves Objective and Subjective Image Quality for High-Pitch Photon Counting Coronary CT Angiography.

(1) Background: Photon-counting detector (PCD) CT offers a wide variety of kernels and sharpness levels for image reconstruction. The aim of this retrospective study was to determine optimal settings for coronary CT angiography (CCTA). (2) Methods: Thirty patients (eight female, mean age 63 ± 13 years) underwent PCD-CCTA in a high-pitch mode.

Portal hypertension in patients with hepatocellular carcinoma and immunotherapy: prognostic relevance of CT-morphologic estimates.

Background: Clinically significant portal hypertension (CSPH) has been identified as an important prognostic factor in patients with hepatocellular carcinoma (HCC) undergoing curative treatment. This study aimed to assess PH estimates as prognostic factors in patients with HCC treated with immunotherapy.

Methods: All patients with HCC treated with an immunotherapeutic agent in first or subsequent lines at our tertiary care center between 2016 and 2021 were included (n = 50).

Dose Reduction and Image Quality in Photon-counting Detector High-resolution Computed Tomography of the Chest: Routine Clinical Data.

Purpose: Photon-counting detector computed tomography (PCD-CT) has the potential to significantly improve CT imaging in many ways including, but not limited to, low-dose high-resolution CT (HRCT) of the lung. The aim of this study was to perform an intrapatient comparison of the radiation dose and image quality of PCD-CT compared with conventional energy-integrating detector CT (EID-CT).

Methods: A total of 32 consecutive patients with available PCD-CT and EID-CT HRCT scans were included in the final analysis.

Commercial AI solutions in detecting COVID-19 pneumonia in chest CT: not yet ready for clinical implementation?

Objectives: In response to the COVID-19 pandemic, many researchers have developed artificial intelligence (AI) tools to differentiate COVID-19 pneumonia from other conditions in chest CT. However, in many cases, performance has not been clinically validated. The aim of this study was to evaluate the performance of commercial AI solutions in differentiating COVID-19 pneumonia from other lung conditions.

Extent of portal vein tumour thrombosis in patients with hepatocellular carcinoma: The more, the worse?

Background & Aims: Portal vein tumour thrombosis (PVTT) has a significant impact on the prognosis of patients with hepatocellular carcinoma (HCC). The degree of PVTT varies from sub-/segmental invasion to complete occlusion of the main trunk. Aim of this study was to evaluate whether the degree of PVTT correlates with prognosis.

Magnetic resonance imaging of (1)H long lived states derived from parahydrogen induced polarization in a clinical system.

Hyperpolarization is a powerful tool to overcome the low sensitivity of nuclear magnetic resonance (NMR). However, applications are limited due to the short lifetime of this non equilibrium spin state caused by relaxation processes. This issue can be addressed by storing hyperpolarization in slowly decaying singlet spin states which was so far mostly demonstrated for non-proton spin pairs, e.

Contrast agent bolus dispersion in a realistic coronary artery geometry: influence of outlet boundary conditions.

Myocardial blood flow (MBF) quantification using contrast-enhanced first-pass magnetic resonance imaging relies on the precise knowledge of the arterial input function (AIF). Due to vascular transport processes, however, the shape of the AIF may change from the left ventricle where the AIF is measured to the myocardium. We employed computational fluid dynamics simulations in a realistic model of the left circumflex artery to investigate the degree to which this effect corrupts MBF quantification.

Computational fluid dynamics simulations of contrast agent bolus dispersion in a coronary bifurcation: impact on MRI-based quantification of myocardial perfusion.

Contrast-enhanced first-pass magnetic resonance imaging (MRI) in combination with a tracer kinetic model, for example, MMID4, can be used to determine myocardial blood flow (MBF) and myocardial perfusion reserve (MPR). Typically, the arterial input function (AIF) required for this methodology is estimated from the left ventricle (LV). Dispersion of the contrast agent bolus might occur between the LV and the myocardial tissue.

Quantitative myocardial perfusion magnetic resonance imaging: the impact of pulsatile flow on contrast agent bolus dispersion.

Myocardial blood flow (MBF) can be quantified using T1-weighted first-pass magnetic resonance imaging (MRI) in combination with a tracer-kinetic model, like MMID4. This procedure requires the knowledge of an arterial input function which is usually estimated from the left ventricle (LV). Dispersion of the contrast agent bolus may occur between the LV and the tissue of interest.

Quantitative contrast-enhanced myocardial perfusion magnetic resonance imaging: simulation of bolus dispersion in constricted vessels.

Quantification of myocardial blood flow (MBF) by means of T1-weighted first-pass magnetic resonance imaging (MRI) requires knowledge of the arterial input function (AIF), which is usually estimated from the left ventricle (LV). Dispersion of the contrast agent bolus may occur between the LV and the tissue of interest, which leads to systematic underestimation of the MBF. The aim of this study was to simulate the dispersion along a simplified coronary artery with different stenoses.