Myocardial characterization using late enhancement photon-counting detector CT in ventricular arrhythmia: comparison with electroanatomical mapping.

Objectives: This study aimed to assess the feasibility of left ventricular myocardial characterization in patients with ventricular arrhythmias using late enhancement (LE) photon-counting detector computed tomography (PCD-CT) scans, in comparison with invasive endocardial electroanatomical mapping (EAM).

Materials And Methods: This single-center retrospective observational study included 20 patients (mean age 64 ± 8 years, 4 female) who underwent PCD-CT prior to 3D endocardial uni- and bipolar EAM and radiofrequency catheter ablation (RFCA) between May 2022 and February 2024. Sixteen patients (80%) had cardiac implantable electronic devices.

Deep Learning-based Automated Coronary Plaque Quantification: First Demonstration With Ultra-high Resolution Photon-counting Detector CT at Different Temporal Resolutions.

Objectives: The aim of this study was to evaluate the feasibility and reproducibility of a novel deep learning (DL)-based coronary plaque quantification tool with automatic case preparation in patients undergoing ultra-high resolution (UHR) photon-counting detector CT coronary angiography (CCTA), and to assess the influence of temporal resolution on plaque quantification.

Materials And Methods: In this retrospective single-center study, 45 patients undergoing clinically indicated UHR CCTA were included. In each scan, 2 image data sets were reconstructed: one in the dual-source mode with 66 ms temporal resolution and one simulating a single-source mode with 125 ms temporal resolution.

Validation of SUV thresholds in [¹⁸F]SiTATE PET/CT for accurate meningioma segmentation.

Purpose: Somatostatin receptor (SSTR)-targeted PET/CT provides valuable clinical insights beyond standard imaging in meningioma patients. Due to its excellent diagnostic capabilities and favorable logistics, the F-labeled SSTR-targeting peptide SiTATE is increasingly in demand. We aimed to validate a recently proposed standard uptake value (SUV) threshold for accurate meningioma delineation in a clinically diverse patient cohort, including complex anatomical locations and lesions with prior surgical intervention.

Contrast media and radiation dose optimization with task-based automatic keV selection: a proof-of-concept study with photon-counting detector CT.

Objectives: To evaluate whether task-based automatic keV selection of photon-counting detector (PCD)-CT with optimizing radiation and contrast media (CM) dose yields consistent image quality in CT angiography (CTA).

Materials And Methods: PCD-CTA of the aorta was performed in six healthy minipigs across two scan sessions, with virtual monoenergetic images (VMI) reconstructed. In the first session, three protocols were conducted: the reference protocol A1 simulated standard CTA (210 mg iodine/kg CM, image quality (IQ)-level 117, non-contrast task, VMI: 70 keV); protocol A2 reduced radiation while keeping CM dose constant (210 mgI/kg, IQ-level 117, vascular task, VMI: 55 keV); and protocol A3 reduced CM dose while maintaining radiation (164 mgI/kg, IQ-level 117, non-contrast task, VMI: 55 keV).

Consistent Visualization of the Round Window Niche Veil With Ultrahigh-Resolution Photon-Counting Detector CT.

Objective: To assess whether the ultrahigh-resolution (UHR) mode of photon-counting detector (PCD) CT can consistently visualize the round window niche veil (RWNV) in human ex vivo specimens.

Samples: This ex vivo study was conducted on nine human cadaveric temporal bones (four male and five female body donors) with an average age of 72 years (range of 56-83 yr).

Intervention: Imaging with a dual-source PCD-CT scanner in ultrahigh-resolution (UHR) mode.

Myocardial Late Enhancement With Photon-Counting Detector CT in Spontaneous Coronary Artery Dissection: Prospective Comparison With Cardiac MRI.

Objectives: Spontaneous coronary artery dissection (SCAD) is a rare cause of acute coronary syndrome and myocardial infarction. Accurate diagnosis is crucial for appropriate management. This study aimed to compare late enhancement (LE) imaging using photon-counting detector (PCD)-CT with cardiac MRI in patients with SCAD in the acute phase and during follow-up and to introduce a novel approach for visualizing myocardial extracellular volume (ECV) distribution in the myocardium.

Reducing contrast media and radiation dose in CT angiography at low tube voltage: animal study with photon-counting detector CT.

Background: Reducing radiation and contrast media (CM) doses in computed tomography angiography (CTA) is especially relevant for potentially vulnerable populations. Low tube voltage photon-counting detector CT (PCD-CT) offers an improved iodine contrast-to-noise ratio (CNR) as compared to conventional CT scanners. We investigated optimized radiation and CM doses of PCD-CT angiography at low tube voltage in an animal model.

In Vivo Bone Mineral Density Assessment With Spectral Localizer Radiographs From Photon-Counting Detector CT: Prospective Comparison With DXA.

Purpose: The aim of this study was to determine in a prospective patient study the accuracy of areal bone mineral density (aBMD) measurements with spectral localizer radiographs obtained with a clinical photon-counting detector computed tomography (PCD-CT) scanner in comparison with dual-energy x-ray absorptiometry (DXA).

Methods: In this institutional review board-approved, prospective study, 41 patients (15 females, 26 males; mean age 61.3 years, age range 35-78 years) underwent PCD-CT of the abdomen with a spectral localizer radiograph (tube voltage 140 kVp, tube current 30 mA) and DXA within a median of 45 days.

Relationship Between Myocardial Strain and Extracellular Volume: Exploratory Study in Patients with Severe Aortic Stenosis Undergoing Photon-Counting Detector CT.

: Diffuse myocardial fibrosis and altered deformation are relevant prognostic factors in aortic stenosis (AS) patients. The aim of this exploratory study was to investigate the relationship between myocardial strain, and myocardial extracellular volume (ECV) in patients with severe AS with a photon-counting detector (PCD)-CT. : We retrospectively included 77 patients with severe AS undergoing PCD-CT imaging for transcatheter aortic valve replacement (TAVR) planning between January 2022 and May 2024 with a protocol including a non-contrast cardiac scan, an ECG-gated helical coronary CT angiography (CCTA), and a cardiac late enhancement scan.

Multienergy cardiovascular CT imaging: current state and future.

Multienergy cardiovascular CT imaging can be defined as data acquisition at 2 (dual-energy) or multiple X-ray energies. Multienergy cardiovascular CT imaging provides additional qualitative and quantitative information such as material maps or virtual monoenergetic images, which are supposed to further improve the quality and diagnostic yield of CT. Recently introduced photon-counting detector CT scanners further address some of the challenges and limitations of previous, conventional CT machines, hereby enhancing and extending the applications of CT for cardiovascular imaging.

The pericoronary adipose tissue attenuation in CT strongly depends on kernels and iterative reconstructions.

Objectives: To investigate the influence of kernels and iterative reconstructions on pericoronary adipose tissue (PCAT) attenuation in coronary CT angiography (CCTA).

Materials And Methods: Twenty otherwise healthy subjects (16 females; median age 52 years) with atypical chest pain, low risk of coronary artery disease (CAD), and without CAD in photon-counting detector CCTA were included. Images were reconstructed with a quantitative smooth (Qr36) and three vascular kernels of increasing sharpness levels (Bv36, Bv44, Bv56).

Advanced myocardial characterization and function with cardiac CT.

Non-invasive imaging with characterization and quantification of the myocardium with computed tomography (CT) became feasible owing to recent technical developments in CT technology. Cardiac CT can serve as an alternative modality when cardiac magnetic resonance imaging and/or echocardiography are contraindicated, not feasible, inconclusive, or non-diagnostic. This review summarizes the current and potential future role of cardiac CT for myocardial characterization including a summary of late enhancement techniques, extracellular volume quantification, and strain analysis.

Effect of Vessel Attenuation, VMI Level, and Reconstruction Kernel on Pericoronary Adipose Tissue Attenuation for EID CT and PCD CT: An Ex Vivo Porcine Heart Study.

Pericoronary adipose tissue (PCAT) attenuation and the fat attenuation index (FAI) may serve as markers of inflammation and the risk of adverse cardiac events. However, standardization of relevant CT acquisition and reconstruction parameters is lacking. The purpose of this study was to investigate the influence of vessel attenuation, the virtual monoenergetic image (VMI) level, and the reconstruction kernel on PCAT attenuation and FAI by use of energy-integrating detector (EID) and photon-counting detector (PCD) CT systems in an ex vivo porcine heart model.

Patient eligibility for trials with imaging response assessment at the time of molecular tumor board presentation.

Purpose: To assess the eligibility of patients with advanced or recurrent solid malignancies presented to a molecular tumor board (MTB) at a large precision oncology center for inclusion in trials with the endpoints objective response rate (ORR) or duration of response (DOR) based on Response Evaluation Criteria in Solid Tumors (RECIST version 1.1).

Methods: Prospective patients with available imaging at the time of presentation in the MTB were included.

[Ultrasound diagnostics of the liver : Principles and important pathologies].

Diffuse changes in the liver parenchyma, focal lesions and blood flow in hepatic vessels can be assessed using ultrasound. Screening by ultrasound can be used to detect hepatocellular carcinomas as possible malignant sequelae of liver cirrhosis. As metastases are far more frequent than primary malignant liver tumors, secondary malignant neoplasms should be taken into consideration as a differential diagnosis in the presence of focal liver lesions.

Radiation Dose and Image Quality of a High-Pitch Prospective Spiral First Approach in Coronary Computed Tomography Angiography (CCTA).

To investigate a high-pitch spiral first (HPSF) approach for coronary computed tomography angiography (CCTA) in an unselected patient cohort and compare diagnostic yield and radiation exposure to CCTAs acquired via conventional, non-high-pitch spiral first (NHPSF) scan regimes. All consecutive patients from 1 January 2015 to 31 December 2017 were included. Two investigation protocols (HPSF/NHPSF) were used with the aim to achieve diagnostic image quality of all coronary segments.