Aortic pulse wave velocity in children with Cushing syndrome: A window into a marker of early cardiovascular disease.

ObjectiveTo investigate early signs of cardiovascular arterial remodelling in paediatric patients with Cushing syndrome (CS) in comparison with normative values from healthy children.Study designThe metrics used to assess cardiac health were from thoracic aorta and carotid MRI. Scans were performed on 18 children with CS (mean: 12.5 ± 3.1 years, range: 6.0-16.8 years, 10 female). Pulse wave velocity (PWV), aortic distensibility (AD) and carotid intima-media thickness (cIMT), well-validated measurements of cardiac compromise, were measured from the images and compared to normative age-matched values where available.ResultsPatients with CS had significantly higher PWV compared to age-adjusted normal median control values (4.0 ± 0.7 m/s vs. 3.4 ± 0.2 m/s, respectively, P = 0.0115). PWV was positively correlated with midnight plasma cortisol (r = 0.56, P = 0.02). Internal and common cIMT were negatively correlated with ascending AD (r = -0.75, P = 0.0022, r = -0.69, P = 0.0068, respectively).ConclusionPulse wave velocity data indicate that paediatric patients with CS have early evidence of cardiovascular remodelling. The results suggest the opportunity for monitoring as these changes begin in childhood

Increased Myocardial Extracellular Volume in Active Idiopathic Systemic Capillary Leak Syndrome

BACKGROUND: The Systemic Capillary Leak Syndrome (SCLS) is a rare disorder of unknown etiology presenting as recurrent episodes of shock and peripheral edema due to leakage of fluid into soft tissues. Insights into SCLS pathogenesis are few due to the scarcity of cases, and the etiology of vascular barrier disruption in SCLS is unknown. Recent advances in cardiovascular magnetic resonance (CMR) allow for the quantitative assessment of the myocardial extracellular volume (ECV), which can be increased in conditions causing myocardial edema. We hypothesized that measurement of myocardial ECV may detect myocardial vascular leak in patients with SCLS. METHODS: Fifty-six subjects underwent a standard CMR examination at the NIH Clinical Center from 2009 until 2014: 20 patients with acute intermittent SCLS, six subjects with chronic SCLS, and 30 unaffected controls. Standard volumetric measurements; late gadolinium enhancement imaging and pre- and post-contrast T1 mapping were performed. ECV was calculated by calibration of pre- and post-contrast T1 values with blood hematocrit. RESULTS: Demographics and cardiac parameters were similar in both groups. There was no significant valvular disorder in either group. Subjects with chronic SCLS had higher pre-contrast myocardial T1 compared to healthy controls (T1: 1027 ± 44 v. 971 ± 41, respectively; p = 0.03) and higher myocardial ECV than patients with acute intermittent SCLS or controls: 33.8 ± 4.6, 26.9 ± 2.6, 26 ± 2.4, respectively; p = 0.007 v. acute intermittent; P = 0.0005 v. controls). When patients with chronic disease were analyzed together with five patients with acute intermittent disease who had just experienced an acute SCLS flare, ECV values were significantly higher than in subjects with acute intermittent SCLS in remission or age-matched controls and (31.2 ± 4.6 %, 26.5 ± 2.7 %, 26 ± 2.4 %, respectively; p = 0.01 v. remission, p = 0.001 v. controls). By contrast, T1 values did not distinguish these three subgroups (1008 ± 40, 978 ± 40, 971 ± 41, respectively, p = 0.2, active v. remission; p = 0.06 active v. controls). Abundant myocardial edema without evidence of acute inflammation was detected in cardiac tissue postmortem in one patient. CONCLUSIONS: Patients with active SCLS have significantly higher myocardial ECV than age-matched controls or SCLS patients in remission, which correlated with histopathological findings in one patient

Imaging transformer for MRI denoising with the SNR unit training: enabling generalization across field-strengths, imaging contrasts, and anatomy

The ability to recover MRI signal from noise is key to achieve fast acquisition, accurate quantification, and high image quality. Past work has shown convolutional neural networks can be used with abundant and paired low and high-SNR images for training. However, for applications where high-SNR data is difficult to produce at scale (e.g. with aggressive acceleration, high resolution, or low field strength), training a new denoising network using a large quantity of high-SNR images can be infeasible. In this study, we overcome this limitation by improving the generalization of denoising models, enabling application to many settings beyond what appears in the training data. Specifically, we a) develop a training scheme that uses complex MRIs reconstructed in the SNR units (i.e., the images have a fixed noise level, SNR unit training) and augments images with realistic noise based on coil g-factor, and b) develop a novel imaging transformer (imformer) to handle 2D, 2D+T, and 3D MRIs in one model architecture. Through empirical evaluation, we show this combination improves performance compared to CNN models and improves generalization, enabling a denoising model to be used across field-strengths, image contrasts, and anatomy

SCMR level II/independent practitioner training guidelines for cardiovascular magnetic resonance: integration of a virtual training environment

Cardiovascular magnetic resonance (CMR) is an important non-invasive imaging modality used for the evaluation of patients with known or suspected heart disease. Despite its clinical importance, CMR is currently not widely available, in part, because of a scarcity of well-trained physicians to perform and interpret the exam. Moreover, current 2018 Society for Cardiovascular Magnetic Resonance (SCMR) training guidelines [1] and also training guidelines from other societies [2, 3] require a significant amount of in-person hands-on experience making training inaccessible for many individuals. This limits the availability of physicians appropriately trained to perform and interpret CMR exams. The purpose of this statement is to provide guidance for implementing a high-quality virtual CMR training program to complement in-person training options

Concordance and diagnostic accuracy of vasodilator stress cardiac MRI and 320-detector row coronary CTA

Vasodilator stress cardiac magnetic resonance (CMR) detects ischemia whereas coronary CT angiography (CTA) detects atherosclerosis. The purpose of this study was to determine concordance and accuracy of vasodilator stress CMR and coronary CTA in the same subjects. We studied 151 consecutive subjects referred to detect or exclude suspected obstructive coronary artery disease (CAD) in patients without known disease or recurrent stenosis or ischemia in patients with previously treated CAD. Vasodilator stress CMR was performed on a 1.5 T scanner. CTA was performed on a 320-detector row system. Subjects were followed for cardiovascular events and downstream diagnostic testing. Subjects averaged 56 ± 12 years (60 % male), and 62 % had intermediate pre-test probability for obstructive CAD. Follow-up averaged 450 ± 115 days and was 100 % complete. CMR and CTA agreed in 92 % of cases (κ 0.81, p < 0.001). The event-free survival was 97 % for non-ischemic and 39 % for ischemic CMR (p < 0.0001). The event-free survival was 99 % for non-obstructive and 36 % for obstructive CTA (p < 0.0001). Using a reference standard including quantitative invasive angiography or major cardiovascular events, CMR and CTA had respective sensitivities of 93 and 98 %; specificities of 96 and 96 %; positive predictive values of 91 and 91 %; negative predictive values of 97 and 99 %; and accuracies of 95 and 97 %. Non-ischemic vasodilator stress CMR or non-obstructive coronary CTA were highly concordant and each confer an excellent prognosis. CMR and CTA are both accurate for assessment of obstructive CAD in a predominantly intermediate risk population