Ascending Aorta 4D Time to Peak Distention Sexual Dimorphism and Association with Coronary Plaque Burden Severity in Women.

Coronary artery disease (CAD) risk and plaque scores are often subjective and biased, particularly in mid-age asymptomatic women, whose CAD risk assessment has been historically underestimated. In this study, a new automatic ascending aorta time-to-peak-distention (TPD) analysis was developed for fast screening and as an independent surrogate for subclinical atherosclerosis in asymptomatic women. CCTA was obtained in 50 asymptomatic adults. Plaque burden segment involvement score (SIS) and automatic TPD were obtained from all subjects. Logistic regression analyses were performed to investigate the association between CAD risk scores and TPD with severe coronary plaque burden (SIS>5). TPD, individually, was found to be a significant predictor of SIS>5. Additionally, sex was a significant effect modifier of TPD, with a stronger statistically significant association with women. Four-dimensional aortic time-to-peak distention could supplement conventional CCTA analysis and offer a quick objective screening tool for plaque burden severity and CAD risk stratification, especially in women.

Retinal vessel diameters: Can they predict future risk of infertility in patients with varicocele?

OBJECTIVE: The objective of this study was to assess the relationship between retinal vessel diameters, such as retinal arteriolar diameter, retinal venular diameter, and arteriolar/venular ratio (AVR), as clinical parameters of fertility in varicocele patients. MATERIALS AND METHODS: Sixty-eight (68) infertile varicocele men with abnormal semen parameters and sixty-one (61) varicocele normozoospermic men were included in the study. Moreover, fifty-eight (58) healthy normozoospermic men without varicocele were enrolled as a control group. For each participant, retinal vascular diameters were measured from the digital retinal photographs as a central retinal arteriolar equivalent (CRAE), central retinal venular equivalent (CRVE), and AVR. In addition, hormones (total testosterone and FSH), and semen parameters were assessed and correlated with retinal vessel diameters. RESULTS: The mean CRAE, CRVE, and AVR values were 147.8 ± 15.8 µm, 198.3 ± 39.3 µm, and 0.61 ± 0.01 in infertile varicocele patients, respectively. Significant difference of CRAE, CRVE, and AVR were found when comparing infertile varicocele patients with both varicocele and control normozoospermic male groups (p = 0.01, p = 0.006, and p = 0.007; respectively). Larger retinal venular caliber and smaller AVR ratio showed a significant inverse correlation with both sperm parameters and hormones (total testosterone and FSH) (p < 0.05). No significant correlations were found between CRAE with both sperm parameters and hormonal values (total testosterone and FSH) (p > 0.05). CONCLUSIONS: Infertile patients with varicocele showed a significant relationship with the retinal vascular diameter (CRVE and AVR ratio). This finding supports recommendation for regular eye examinations in the varicocele population.

Native-resolution myocardial principal Eulerian strain mapping using convolutional neural networks and Tagged Magnetic Resonance Imaging.

BACKGROUND: Assessment of regional myocardial function at native pixel-level resolution can play a crucial role in recognizing the early signs of the decline in regional myocardial function. Extensive data processing in existing techniques limits the effective resolution and accuracy of the generated strain maps. The purpose of this study is to compute myocardial principal strain maps εp1 and εp2 from tagged MRI (tMRI) at the native image resolution using deep-learning local patch convolutional neural network (CNN) models (DeepStrain). METHODS: For network training, validation, and testing, realistic tMRI datasets were generated and consisted of 53,606 cine images simulating the heart, the liver, blood pool, and backgrounds, including ranges of shapes, positions, motion patterns, noise, and strain. In addition, 102 in-vivo image datasets from three healthy subjects, and three Pulmonary Arterial Hypertension patients, were acquired and used to assess the network's in-vivo performance. Four convolutional neural networks were trained for mapping input tagging patterns to corresponding ground-truth principal strains using different cost functions. Strain maps using harmonic phase analysis (HARP) were obtained with various spectral filtering settings for comparison. CNN and HARP strain maps were compared at the pixel level versus the ground-truth and versus the least-loss in-vivo maps using Pearson correlation coefficients (R) and the median error and Inter-Quartile Range (IQR) histograms. RESULTS: CNN-based local patch DeepStrain maps at a phantom resolution of 1.1mm × 1.1 mm and in-vivo resolution of 2.1mm × 1.6 mm were artifact-free with multiple fold improvement with εp1 ground-truth median error of 0.009(0.007) vs. 0.32(0.385) using HARP and εp2 ground-truth error of 0.016(0.021) vs. 0.181(0.08) using HARP. CNN-based strain maps showed substantially higher agreement with the ground-truth maps with correlation coefficients R > 0.91 for εp1 and εp2 compared to R < 0.21 and R < 0.82 for HARP-generated maps, respectively. CONCLUSION: CNN-generated Eulerian strain mapping permits artifact-free visualization of myocardial function at the native image resolution.

Improved Centerline Extraction in Fully Automated Coronary Ostium Localization and Centerline Extraction Framework using Deep Learning.

Coronary artery extraction in cardiac CT angiography (CCTA) image volume is a necessary step for any quantitative assessment of stenoses and atherosclerotic plaque. In this work, we propose a fully automated workflow that depends on convolutional networks to extract the centerlines of the coronary arteries from CCTA image volumes, starting from identifying the ostium points and then tracking the vessel till its end based on its radius and direction. First, a regression U-Net is employed to identify the ostium points in the image volume, then these points are fed to an orientation and radius predictor CNN model to track and extract each artery till its end point. Our results show that an average of 96% of the ostium points were identified and located within less than 5mm from their true location. The coronary arteries centerlines extraction was performed with high accuracy and lower number of training parameters making it suitable for real clinical applications and continuous learning.

Direct pixel to pixel principal strain mapping from tagging MRI using end to end deep convolutional neural network (DeepStrain).

Regional soft tissue mechanical strain offers crucial insights into tissue's mechanical function and vital indicators for different related disorders. Tagging magnetic resonance imaging (tMRI) has been the standard method for assessing the mechanical characteristics of organs such as the heart, the liver, and the brain. However, constructing accurate artifact-free pixelwise strain maps at the native resolution of the tagged images has for decades been a challenging unsolved task. In this work, we developed an end-to-end deep-learning framework for pixel-to-pixel mapping of the two-dimensional Eulerian principal strains [Formula: see text] and [Formula: see text] directly from 1-1 spatial modulation of magnetization (SPAMM) tMRI at native image resolution using convolutional neural network (CNN). Four different deep learning conditional generative adversarial network (cGAN) approaches were examined. Validations were performed using Monte Carlo computational model simulations, and in-vivo datasets, and compared to the harmonic phase (HARP) method, a conventional and validated method for tMRI analysis, with six different filter settings. Principal strain maps of Monte Carlo tMRI simulations with various anatomical, functional, and imaging parameters demonstrate artifact-free solid agreements with the corresponding ground-truth maps. Correlations with the ground-truth strain maps were R = 0.90 and 0.92 for the best-proposed cGAN approach compared to R = 0.12 and 0.73 for the best HARP method for [Formula: see text] and [Formula: see text], respectively. The proposed cGAN approach's error was substantially lower than the error in the best HARP method at all strain ranges. In-vivo results are presented for both healthy subjects and patients with cardiac conditions (Pulmonary Hypertension). Strain maps, obtained directly from their corresponding tagged MR images, depict for the first time anatomical, functional, and temporal details at pixelwise native high resolution with unprecedented clarity. This work demonstrates the feasibility of using the deep learning cGAN for direct myocardial and liver Eulerian strain mapping from tMRI at native image resolution with minimal artifacts.

The predictive value of the platelet volume parameters in evaluation of varicocelectomy outcome in infertile patients.

The aim of this study was to evaluate the role of platelet count (PLT) and platelet volume indices (PVI) such as mean platelet volume (MPV), platelet distribution width (PDW) and plateletcrit (PCT) as a clinical biomarker in 64 infertile males with varicocele and 45 controls. In addition, semen parameters, serum total testosterone, FSH and testicular volume were measured before and at 6 months after varicocelectomy. The mean PLT, MPV, PDW and PCT were 231 ± 42 × 103/µl, 9.6 ± 1.8 fl, 16.2 ± 2.5 fl and 0.18% in the patient group respectively. When the patient and control groups were compared, there was a significant increase in mean MPV, PDW and PCT (p < .0001), while platelet count was lower in patients than control group, but with no significant relationship. MPV had a significant negative correlation with total testosterone (p < .03). No significant correlations were found between PVI and testicular volume. After follow-up of 37.1 ± 1.9 months, a significant negative correlation was found between the preoperative MPV and varicocelectomy outcome in terms of semen values (p < .007). So, the increase in MPV and low total testosterone in men with varicocele may be a feature of high risk of infertility.

Automatic Coronary Wall and Atherosclerotic Plaque Segmentation from 3D Coronary CT Angiography.

Coronary plaque burden measured by coronary computerized tomography angiography (CCTA), independent of stenosis, is a significant independent predictor of coronary heart disease (CHD) events and mortality. Hence, it is essential to develop comprehensive CCTA plaque quantification beyond existing subjective plaque volume or stenosis scoring methods. The purpose of this study is to develop a framework for automated 3D segmentation of CCTA vessel wall and quantification of atherosclerotic plaque, independent of the amount of stenosis, along with overcoming challenges caused by poor contrast, motion artifacts, severe stenosis, and degradation of image quality. Vesselness, region growing, and two sequential level sets are employed for segmenting the inner and outer wall to prevent artifact-defective segmentation. Lumen and vessel boundaries are joined to create the coronary wall. Curved multiplanar reformation is used to straighten the segmented lumen and wall using lumen centerline. In-vivo evaluation included CCTA stenotic and non-stenotic plaques from 41 asymptomatic subjects with 122 plaques of different characteristics against the individual and consensus of expert readers. Results demonstrate that the framework segmentation performed robustly by providing a reliable working platform for accelerated, objective, and reproducible atherosclerotic plaque characterization beyond subjective assessment of stenosis; can be potentially applicable for monitoring response to therapy.

Automatic Assessment of 3D Coronary Artery Distensibility from Time-Resolved Coronary CT Angiography.

Measuring coronary artery distensibility can determine the arterial remodeling type, arterial wall inflammation, and atherosclerotic plaques in early stage even before any observed narrowing in the lumen. This is crucial to promote an appropriate, preventive, and effective treatment. This study introduces a framework for calculating the 3D distensibility of the left coronary artery (LCA) from time-resolved coronary computerized tomography angiography (CCTA) images. Vesselness, region growing, and level sets are utilized for segmenting the LCA lumen in the systole and diastole CCTA time frames. The segmented arteries are then analyzed and registered using computational geometry to calculate the changes in the lumen cross-section areas between both time frames. In-vivo validation of the framework performance was accomplished against that of two radiologists and their consensus. Results demonstrate that the framework was accurate and reliable tool for measuring the coronary arteries distensibility.

Sexual Dimorphism of Coronary Artery Disease in a Low- and Intermediate-Risk Asymptomatic Population: Association with Coronary Vessel Wall Thickness at MRI in Women.

PURPOSE: To demonstrate the association between coronary vessel wall thickness (VWT) measured at MRI and coronary artery disease (CAD) risk in asymptomatic groups at low and intermediate risk on the basis of Framingham score. MATERIALS AND METHODS: A total of 131 asymptomatic adults were prospectively enrolled. All participants underwent CT angiography for scoring CAD, and coronary VWT was measured at 3.0-T MRI. Nonlinear single and multivariable regression analyses with consideration for interaction with sex were performed to investigate the association of traditional atherosclerotic risk factors and VWT with CT angiography-based CAD scores. RESULTS: The analysis included 62 women and 62 men with low or intermediate Framingham score of less than 20%. Age (mean age, 45.0 years ± 14.5 [standard deviation]) and body mass index were not different between the groups. Age, sex, and VWT were individually significantly associated with all CT angiography-based CAD scores (P < .05). Additionally, sex was a significant effect modifier of the associations with all CAD scores. In men, age was the only statistically significant independent risk factor of CAD; in women, VWT was the only statistically significant independent surrogate associated with increased CAD scores (P < .05). CONCLUSION: In asymptomatic women, VWT MRI was the primary independent surrogate of CAD, whereas age was the strongest risk factor in men. This study suggests that VWT may be used as a CAD surrogate in women at low or intermediate risk of CAD. Further longitudinal studies are required to determine the potential implication and use of this MRI technique for the preventative management of CAD in women.© RSNA, 2019.

Rheological determinants for simultaneous staging of hepatic fibrosis and inflammation in patients with chronic liver disease.

The purpose of this study is to investigate the use of fundamental rheological parameters as quantified by MR elastography (MRE) to measure liver fibrosis and inflammation simultaneously in humans. MRE was performed on 45 patients at 3 T using a vibration frequency of 56 Hz. Fibrosis and inflammation scores were obtained from liver biopsies. Biomechanical properties were quantified in terms of complex shear modulus G* as well as shear wave phase velocity c and shear wave attenuation α. A rheological fractional derivative order model was used to investigate the linear dependence of the free model parameters (dispersion slope y, intrinsic speed c0 , and intrinsic relaxation time τ) on histopathology. Leave-one-out cross-validation was then utilized to demonstrate the effectiveness of the model. The intrinsic speed c0 increases with hepatic fibrosis, while an increased relaxation time τ is reflective of more inflammation of the liver parenchyma. The dispersion slope y does not depend either on fibrosis or on inflammation. The proposed rheological model, given this specific parameterization, establishes the functional dependences of biomechanical parameters on histological fibrosis and inflammation. The leave-one-out cross-validation demonstrates that the model allows identification, from the MRE measurements, of the histology scores when grouped into low-/high-grade fibrosis and low-/high-grade inflammation with significance levels of P = 0.0004 (fibrosis) and P = 0.035 (inflammation). The functional dependences of intrinsic speed and relaxation time on fibrosis and inflammation, respectively, shed new light onto the impact hepatic pathological changes on liver tissue biomechanics in humans. The dispersion slope y appears to represent a structural parameter of liver parenchyma not impacted by the severity of fibrosis/inflammation present in this patient cohort. This specific parametrization of the well-established rheological fractional order model is valuable for the clinical assessment of both fibrosis and inflammation scores, going beyond the capability of the plain shear modulus measurement commonly used for MRE.

Coronary calcification in adults with Turner syndrome.

PurposeAdults with Turner syndrome (TS) have an increased predisposition to ischemic heart disease. The quantitative relationship between coronary atherosclerosis and TS has yet to be established.MethodsA total of 128 females (62 with TS) participated in this prospective study. Coronary computed tomography angiography was performed to measure coronary calcified plaque burden, and prevalent noncalcified plaque burden. Regression analysis was used to study the effects of TS and traditional cardiovascular disease risk factors on coronary plaque burden.ResultsAdults with TS were 63% more likely to have coronary calcifications than controls (odds ratio 1.63, 95% confidence interval: 1.02, 2.61, P = 0.04), with an age cutoff of 51.7 years for a probability of >50% for the presence of coronary calcifications, when compared to 55.7 years in female controls. The average age of TS patients with calcified plaques was significantly lower than that of controls with calcified plaques (51.5 ± 8.9 years vs. 60.5 ± 7.0 years, P < 0.001). Age increased the likelihood of coronary calcifications by 13% per year (odds ratio 1.13, confidence interval 95%: 1.07-1.19, P < 0.001).ConclusionThis study demonstrates a higher prevalence and earlier onset of calcified coronary plaques in TS. These findings have important implications for cardiovascular risk assessment and the management of patients with TS.

Coronary atherosclerosis and dilation in hyper IgE syndrome patients: Depiction by magnetic resonance vessel wall imaging and pathological correlation.

BACKGROUND AND AIMS: Autosomal dominant hyper-IgE (AD-HIES) is a primary immunodeficiency caused by mutations in STAT3. Elevated levels of IgE, an ineffective immune response, connective tissue abnormalities, and coronary arterial dilation and tortuosity characterize AD-HIES. To date, coronary artery evaluation in AD-HIES patients has been limited to lumenography measurements. Direct in vivo coronary vessel wall (VW) imaging may allow for better interrogation of coronary vessel abnormalities. The goal of this prospective study was to evaluate the coronary VW of AD-HIES patients using Magnetic Resonance Imaging (MRI) and histology. VW image findings were compared in healthy subjects and subjects with coronary atherosclerotic disease (CAD). METHODS: A total of 28 subjects (10 with AD-HIES, 8 healthy, 10 with CAD) were studied by coronary VW MRI imaging. Additionally, a post-mortem coronary artery from one VW imaged AD-HIES patient was examined. RESULTS: Coronary VW in AD-HIES was thicker than in healthy controls but not significantly different from VW thickness in CAD subjects. AD-HIES coronaries showed increased VW area compared to healthy controls and CAD subjects. On histology, the AD-HIES coronary artery had findings consistent with atherosclerotic plaque, but had minimal luminal narrowing, deficient adventitia thickening and absence of both internal and external elastic laminae. CONCLUSIONS: This is the first study to demonstrate subclinical coronary atherosclerosis in AD-HIES patients on VW imaging by MRI. Histologic evaluation confirmed the presence of atherosclerosis with lack of supportive adventitial thickening and elastic components. These findings suggest mechanisms for coronary dilation in AD-HIES and thereby help direct clinical management.