Opportunistic screening at chest computed tomography: literature review of cardiovascular significance of incidental findings.

Background and Objective: Several incidental cardiovascular findings are present in a routine chest computed tomography (CT) scan, many of which do not make it to the final radiology report. However, these findings have important clinical implications, particularly providing prognosis and risk-stratification for future cardiovascular events. The purpose of this article is to review the literature on these incidental cardiovascular findings in a routine chest CT and inform the radiologist on their clinical relevance. Methods: A time unlimited review of PubMed and Web of Science was performed by using relevant keywords. Articles in English that involved adults were included. Key Content and Findings: Coronary artery calcification (CAC) is the most common incidental cardiac finding detected in a routine chest CT and is a significant predictor of cardiovascular events. Noncoronary vascular calcifications in chest CT include aortic valve, mitral annulus, and thoracic aortic calcifications (TAC). Among these, aortic valve calcification (AVC) has the strongest association with coronary artery disease and cardiovascular events. Additional cardiac findings such as myocardial scar and left ventricular size and noncardiac findings such as thoracic fat, bone density, hepatic steatosis, and breast artery calcifications can also help in risk stratification and patient management. Conclusions: The radiologist interpreting a routine chest CT should be cognizant of the incidental cardiovascular findings, which helps in the diagnosis and risk-stratification of cardiovascular disease. This will guide appropriate referral and management.

State-of-the-art pulmonary arterial imaging - Part 1.

The pulmonary arteries are affected by a variety of congenital and acquired abnormalities. Multiple state-of-the art imaging modalities are available to evaluate these pulmonary arterial abnormalities, including computed tomography (CT), magnetic resonance imaging (MRI), echocardiography, nuclear medicine imaging and catheter pulmonary angiography. In part one of this two-part series on state-of-the art pulmonary arterial imaging, we review these imaging modalities, focusing particularly on CT and MRI. We also review the utility of these imaging modalities in the evaluation of pulmonary thromboembolism.

Evaluation of Virtual Monoenergetic Images on Pulmonary Vasculature Using the Dual-Layer Detector-Based Spectral Computed Tomography.

OBJECTIVE: To evaluate the ability of retrospectively generated virtual monoenergetic images (VMIs) from the detector-based spectral computed tomography (SDCT) to augment pulmonary artery enhancement in CT and if iodine map can predict the optimal monoenergetic level. METHODS: The study included 79 patients with contrast-enhanced chest CT scans on an SDCT scanner. Conventional 120-kVp images and VMI from 40 to 80 keV were generated. Attenuation, noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were measured at 7 different locations in the pulmonary arterial system. The iodine concentration (in milligrams per milliliter) was calculated using the iodine-density images. The overall image quality was subjectively graded on a 5-point scale, with 1 being the worst and 5 the best. Fifty-four patients with suboptimal pulmonary enhancement (<200 Hounsfield units [HU]) were then identified. From the VMIs, an ideal set was chosen that maintained mean vascular attenuation greater than 200 HU while maintaining at least diagnostically acceptable quality (ie, IQ score ≥3). At this ideal energy level, quantitative and qualitative parameters were compared with the standard 120-kVp polyenergetic study. Average iodine concentrations were correlated with the optimal keV levels used for salvaging suboptimal studies. RESULTS: The mean attenuation of all the measured pulmonary arterial regions in the suboptimal cases was 136.1 ± 18.1 HU in conventional 120-kVp images. Attenuations of the VMIs at 40, 50, and 60 keV were significantly higher than conventional images measuring 357.5 ± 19.5, 243.6 ± 16.7, and 176.6 ± 15.0 HU, respectively (P < 0.001). Similar results were seen with SNR and CNR. In total, 50 studies can be salvaged, with 50 keV being the optimal energy for 21, 60 keV optimal for 17, and 40 keV optimal for 12 studies. At the optimal energy level, there were improvements of attenuation, SNR, and CNR by 71%, 63%, and 137% compared with conventional images. There was a positive correlation between iodine value and optimal reconstruction energy with a linear equation y = 5.9539x + 27.434 and R = 0.8093. CONCLUSIONS: Suboptimal enhanced pulmonary arterial CT studies can be salvaged using low-energy VMI generated from the SDCT scanner. There were significant improvements of attenuation, SNR, and CNR at the optimal monoenergetic level.

Congenital Anomalies of the Superior Vena Cava: Embryological Correlation, Imaging Perspectives, and Clinical Relevance.

There is a wide spectrum of congenital anomalies of the superior vena cava, which are more increasingly recognized in cross-sectional imaging. Although some of these anomalies are asymptomatic, others have important clinical and interventional implications. Imaging modalities such as computed tomography and magnetic resonance imaging play an important role in the accurate characterization of these anomalies, which is essential for mapping prior to surgeries or interventions. In this article, we review a wide range of anomalies of the superior vena cava, including the embryological basis, cross-sectional imaging findings, and clinical implications, particularly from an interventional radiology perspective. We also discuss the treatments and complications of these anomalies.

Congenital anomalies of the IVC-embryological perspective and clinical relevance.

With the increased use of cross-sectional imaging, systemic venous anomalies are more frequently being recognized in asymptomatic patients. Accurate characterization of systemic venous anomalies plays a major role in the appropriate selection of a surgical approach or interventional procedure. In this article, we review common and uncommon inferior vena cava (IVC) anomalies. We describe the embryological basis and clinical implications of these anomalies, particularly from an interventional radiology perspective. We also discuss the complications and treatments of these anomalies.

Unusual fistulas and connections in the cardiovascular system: A pictorial review.

A fistula is an abnormal vascular connection leading to diversion of blood from a high resistance arterial circuit to low resistance venous circuit. Coronary artery fistulas are abnormal communications of the coronary artery with a chamber of the heart, or with any segment of systemic or pulmonary circulation, bypassing the myocardial capillaries. Other unusual fistulas include connection between aorta and the right atrium/superior vena cava, aorta and the inferior vena cava or between a coronary artery bypass graft and a cardiac vein. Abnormal connections also include origin of the coronary artery from the pulmonary artery. In this article, we review the imaging, particularly computed tomography and magnetic resonance imaging of unusual fistulas and connections involving the cardiovascular system, particularly the coronary arteries and the aorta.