Intraindividual Comparison of Dose Reduction and Coronary Calcium Scoring Accuracy Using Kilovolt-independent and Tin Filtration CT Protocols.

Purpose To investigate the ability of kilovolt-independent (hereafter, kV-independent) and tin filter spectral shaping to accurately quantify the coronary artery calcium score (CACS) and radiation dose reductions compared with the standard 120-kV CT protocol. Materials and Methods This prospective, blinded reader study included 201 participants (mean age, 60 years ± 9.8 [SD]; 119 female, 82 male) who underwent standard 120-kV CT and additional kV-independent and tin filter research CT scans from October 2020 to July 2021.

AI-based, automated chamber volumetry from gated, non-contrast CT.

Background: Accurate chamber volumetry from gated, non-contrast cardiac CT (NCCT) scans can be useful for potential screening of heart failure.

Objectives: To validate a new, fully automated, AI-based method for cardiac volume and myocardial mass quantification from NCCT scans compared to contrasted CT Angiography (CCTA).

Methods: Of a retrospectively collected cohort of 1051 consecutive patients, 420 patients had both NCCT and CCTA scans at mid-diastolic phase, excluding patients with cardiac devices.

Sex differences in machine learning computed tomography-derived fractional flow reserve.

Coronary computed tomography angiography (CCTA) derived machine learning fractional flow reserve (ML-FFR) can assess the hemodynamic significance of coronary artery stenoses. We aimed to assess sex differences in the association of ML-FFR and incident cardiovascular outcomes. We studied a retrospective cohort of consecutive patients who underwent clinically indicated CCTA and single photon emission computed tomography (SPECT).

Interoperator reliability of an on-site machine learning-based prototype to estimate CT angiography-derived fractional flow reserve.

Background: Advances in CT and machine learning have enabled on-site non-invasive assessment of fractional flow reserve (FFR).

Purpose: To assess the interoperator and intraoperator variability of coronary CT angiography-derived FFR using a machine learning-based postprocessing prototype.

Materials And Methods: We included 60 symptomatic patients who underwent coronary CT angiography.

Prognostic Value of Computed Tomography-Derived Fractional Flow Reserve Comparison With Myocardial Perfusion Imaging.

Objectives: The aim of this study was to compare the incremental prognostic value of coronary computed tomography (CT) angiography (CCTA)-derived machine learning fractional flow reserve CT (ML-FFRct) versus that of ischemia detected on single-photon emission-computed tomography (SPECT) myocardial perfusion imaging (MPI) on incident cardiovascular outcomes.

Background: SPECT MPI and ML-FFRct are noninvasive tools that can assess the hemodynamic significance of coronary atherosclerotic disease.

Methods: We studied a retrospective cohort of consecutive patients who underwent clinically indicated CCTA and SPECT MPI.

Evaluating the value of intrapartum fetal scalp blood sampling to predict adverse neonatal outcomes: A UK multicentre observational study.

Objective: To evaluate the value of fetal scalp blood sampling (FBS) as an adjunct test to cardiotocography, to predict adverse neonatal outcomes.

Study Design: A multicentre service evaluation observational study in forty-four maternity units in the UK. We collected data retrospectively on pregnant women with singleton pregnancy who received FBS in labour using a standardised data collection tool.

International variation in radiation dose for computed tomography examinations: prospective cohort study.

Objective: To determine patient, institution, and machine characteristics that contribute to variation in radiation doses used for computed tomography (CT).

Design: Prospective cohort study.

Setting: Data were assembled and analyzed from the University of California San Francisco CT International Dose Registry.

[18F]-Fluorodeoxyglucose PET/CT imaging as a marker of carotid plaque inflammation: Comparison to immunohistology and relationship to acuity of events.

Background: [18F]-fluorodeoxyglucose (FDG) uptake imaged with positron emission tomography (PET) and computed tomography (CT) may serve as a biomarker of plaque inflammation. This study evaluated the relationship between carotid plaque FDG uptake and a) intraplaque expression of macrophage and macrophage-like cellular CD68 immunohistology; b) intraplaque inflammatory burden using leukocyte-sensitive CD45 immunohistology; c) symptomatic patient presentation; d) time from last cerebrovascular event.

Methods: 54 patients scheduled for carotid endarterectomy underwent FDG PET/CT imaging.

The benefits of using a bismuth-containing, radiation-absorbing drape in cardiac resynchronization implant procedures.

Background: Radiation exposure is a major concern in cardiac device implantation, especially cardiac resynchronization therapy (CRT) procedures. The RadPad™ (Worldwide Innovations & Technologies, Inc., Kansas City, MO, USA), a radiation-attenuating adhesive drape, has been shown to be beneficial in several clinical settings involving fluoroscopy, but less is known about the actual benefits in CRT procedures.

Public Health England survey of eye lens doses in the UK medical sector.

The ICRP has recently recommended that the occupational exposure limit for the lens of the eye be reduced to 20 mSv in a year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv. There has been concern amongst some groups of individuals, particularly interventional cardiologists and radiologists as well as relevant professional bodies, that implementation of these recommendations into UK law will adversely affect working patterns. However, despite a number of informative European studies, there is currently little UK dosimetry data available upon which judgements can effectively be based.

A single slice measure of epicardial adipose tissue can serve as an indirect measure of total epicardial adipose tissue burden and is associated with obstructive coronary artery disease.

Aims: To evaluate the practical use of the single slice measurement of epicardial adipose tissue (EAT) at the level of the left main coronary artery (EATLM) in predicting the presence of obstructive coronary artery disease (CAD).

Methods And Results: Quantification of EATTotal and EATLM was performed on non-contrast CT scans of consecutive patients (without history of revascularization, cardiac transplantation, device implantation, and congenital heart disease) who underwent coronary artery calcium (CAC) scoring and computed tomographic coronary angiography (CTA) between May 2011 and July 2011. One hundred and ninety-two patients were evaluated, of which 47 had obstructive CAD (>50% stenosis).

Cardiac PET: metabolic and functional imaging of the myocardium.

Cardiac PET has evolved over the past 30 years to gain wider acceptance as a valuable modality for a variety of cardiac conditions. Wider availability of scanners as well as changes in reimbursement policies in more recent years has further increased its use. Moreover, with the emergence of novel radionuclides as well as further advances in scanner technology, the use of cardiac PET can be expected to increase further in both clinical practice and the research arena.

CT vs SPECT: CT is the first-line test for the diagnosis and prognosis of stable coronary artery disease.

Non-invasive cardiac imaging is pivotal in the diagnosis and prognosis of patients with stable CAD. Nuclear SPECT, PET, stress echocardiography and more recently cardiac magnetic resonance imaging have been utilized with excellent diagnostic accuracy. However, along with their inherent individual limitations, most modalities detect ischemia but lack the ability to define coronary anatomy or evaluate for subclinical atherosclerosis.

Predictive value of cardiac computed tomography and the impact of renal function on all cause mortality (from Coronary Computed Tomography Angiography Evaluation for Clinical Outcomes).

Patients with chronic kidney disease have a worse cardiovascular prognosis than those without. The aim of this study was to determine the incremental prognostic value of coronary computed tomographic angiography in predicting mortality across the entire spectrum of renal function in patients with known or suspected coronary artery disease (CAD). A large international multicenter registry was queried, and patients with left ventricular ejection fraction (LVEF) and creatinine data were screened.

Current and future clinical applications of cardiac positron emission tomography.

Nuclear imaging, predominantly with single-photon emission tomography, has established and demonstrated value for the assessment of cardiovascular disease (CVD). Formerly, the clinical application of positron emission tomography (PET) was precluded by methodological complexity, high operating costs and lack of widespread availability. However, as PET and radiotracer development technologies have improved and continue to do so, PET is expected to become a mainstay diagnostic cardiovascular imaging modality.

Identifying high-risk asymptomatic carotid stenosis.

Introduction: With more intensive medical therapy, the risk of stroke in patients with asymptomatic carotid stenosis (ACS) is now below the risk of carotid endarterectomy or stenting (intervention); ∼ 90% of patients would be better with only medical therapy. It is important, therefore, to have methods to identify the ∼ 10% of patients who stand to benefit from intervention.

Areas Covered: We review the evidence that the risk of asymptomatic stenosis is now below the risk of intervention, and evidence for several approaches to identifying high-risk ACS: transcranial Doppler embolus detection, echolucency and neovascularity on ultrasound, ulceration on three-dimensional ultrasound, plaque composition on magnetic resonance imaging (MRI), plaque inflammation on positron emission tomography and assessment of cerebral blood flow reserve.

The role of F(18)-fluorodeoxyglucose positron emission tomography in guiding diagnosis and management in patients with known or suspected cardiac sarcoidosis.

Cardiac sarcoidosis (CS) has gained significant interest in recent years with the emergence of advanced imaging modalities such as MRI and F(18)-fluorodeoxyglucose-positron emission tomography (FDG-PET) as modalities to aid in the diagnosis of this condition. CS remains a difficult condition to diagnose, particularly in cases of isolated cardiac involvement and it can present with a broad spectrum of clinical syndromes. Furthermore, the appropriate management of these patients remains controversial.

Detection of papillary muscle infarction by late gadolinium enhancement: incremental value of short-inversion time vs. standard imaging.

Aims: Late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) imaging can detect myocardial scar in patients with myocardial infarction. The detection of papillary muscle infarction (PMI) may be difficult due to the bright blood signal. The aim of our study was to evaluate the incremental value of LGE CMR imaging using an inversion recovery (IR)-GRE with a short-inversion time (TI) over standard LGE imaging in identifying PMI.

Imaging atherosclerosis with hybrid [18F]fluorodeoxyglucose positron emission tomography/computed tomography imaging: what Leonardo da Vinci could not see.

Prodigious efforts and landmark discoveries have led toward significant advances in our understanding of atherosclerosis. Despite significant efforts, atherosclerosis continues globally to be a leading cause of mortality and reduced quality of life. With surges in the prevalence of obesity and diabetes, atherosclerosis is expected to have an even more pronounced impact upon the global burden of disease.

A model of primary and scattered photon fluence for mammographic x-ray image quantification.

We present an efficient method to calculate the primary and scattered x-ray photon fluence component of a mammographic image. This can be used for a range of clinically important purposes, including estimation of breast density, personalized image display, and quantitative mammogram analysis. The method is based on models of: the x-ray tube; the digital detector; and a novel ray tracer which models the diverging beam emanating from the focal spot.

Quantification and normalization of x-ray mammograms.

The analysis of (x-ray) mammograms remains qualitative, relying on the judgement of clinicians. We present a novel method to compute a quantitative, normalized measure of tissue radiodensity traversed by the primary beam incident on each pixel of a mammogram, a measure we term the standard attenuation rate (SAR). SAR enables: the estimation of breast density which is linked to cancer risk; direct comparison between images; the full potential of computer aided diagnosis to be utilized; and a basis for digital breast tomosynthesis reconstruction.

Comparison of long and short axis quantification of left ventricular volume parameters by cardiovascular magnetic resonance, with ex-vivo validation.

Background: The purpose of the study was to compare the accuracy and evaluation time of quantifying left ventricular (LV), left atrial (LA) volume and LV mass using short axis (SAX) and long axis (LAX) methods when using cardiovascular magnetic resonance (CMR).

Materials And Methods: We studied 12 explanted canine hearts and 46 patients referred for CMR (29 male, age 47 ± 18 years) in a clinical 1.5 T CMR system, using standard cine sequences.