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5,899 result(s) for "Aorta - diagnostic imaging"
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Automated 3D segmentation and diameter measurement of the thoracic aorta on non-contrast enhanced CT
ObjectivesTo develop and evaluate a fully automatic method to measure diameters of the ascending and descending aorta on non-ECG-gated, non-contrast computed tomography (CT) scans.Material and methodsThe method combines multi-atlas registration to obtain seed points, aorta centerline extraction, and an optimal surface segmentation approach to extract the aorta surface around the centerline. From the extracted 3D aorta segmentation, the diameter of the ascending and descending aorta was calculated at cross-sectional slices perpendicular to the extracted centerline, at the level of the pulmonary artery bifurcation, and at 1-cm intervals up to 3 cm above and below this level. Agreement with manual annotations was evaluated by dice similarity coefficient (DSC) for segmentation overlap, mean surface distance (MSD), and intra-class correlation (ICC) of diameters on 100 CT scans from a lung cancer screening trial. Repeatability of the diameter measurements was evaluated on 617 baseline-one year follow-up CT scan pairs.ResultsThe agreement between manual and automatic segmentations was good with 0.95 ± 0.01 DSC and 0.56 ± 0.08 mm MSD. ICC between the diameters derived from manual and from automatic segmentations was 0.97, with the per-level ICC ranging from 0.87 to 0.94. An ICC of 0.98 for all measurements and per-level ICC ranging from 0.91 to 0.96 were obtained for repeatability.ConclusionThis fully automatic method can assess diameters in the thoracic aorta reliably even in non-ECG-gated, non-contrast CT scans. This could be a promising tool to assess aorta dilatation in screening and in clinical practice.Key Points• Fully automatic method to assess thoracic aorta diameters.• High agreement between fully automatic method and manual segmentations.• Method is suitable for non-ECG-gated CT and can therefore be used in screening.
Aortic Size and Clinical Care Pathways Before Type A Aortic Dissection
Patients with aortic enlargement are recommended to undergo serial imaging and clinical follow-up until they reach surgical thresholds. This study aimed to identify aortic diameter and care of patients with aortic imaging before aortic dissection (AD). In a retrospective cohort of AD patients, we evaluated previous imaging results in addition to ordering providers and indications. Imaging was stratified as >1 or <1 year: 62 patients (53% men) had aortic imaging before AD (most recent test: 82% echo, 11% computed tomography, 6% magnetic resonance imaging). Imaging was ordered most frequently by primary care physicians (35%) and cardiologists (39%). The most frequent imaging indications were arrhythmia (11%), dyspnea (10%), before or after aortic valve surgery (8%), chest pain (6%), and aneurysm surveillance in 13%. Of all patients, 94% had aortic diameters below the surgical threshold before the AD. Imaging was performed <1 year before AD in 47% and aortic size was 4.4 ± 0.8 cm in ascending aorta and 4.0 ± 0.8 cm in sinus. In patients whose most recent imaging was >1 year before AD (1,317 ± 1,017 days), the mean ascending aortic diameter was 4.2 ± 0.4 cm. In conclusion, in a series of patients with aortic imaging before AD, the aortic size was far short of surgical thresholds in 94% of the group. In >50%, imaging was last performed >1 year before dissection.
New potential morphologic features of the aorta associated with the occurrence of acute type B aortic dissection
The present study aimed to identify aortic morphological features associated with the occurrence of acute type B aortic dissection (aTBAD) and establish a risk prediction model. Patients in the control group were age- and sex-matched in a 1:1 ratio with the aTBAD group. Morphological parameters of the ascending aorta and aortic arch were measured on the GE Healthcare Advantage Workstation. The length and diameter of the ascending aorta and aortic arch in the aTBAD group increased significantly (all P  < 0.001). The tortuosity and angulation of ascending aorta were significantly larger in the aTBAD group ( P  < 0.001 and P  = 0.021, respectively), with no significant difference in the aortic arch ( P  = 0.757 and P  = 0.212, respectively). The height and angle of the ascending aorta increased significantly in the aTBAD group ( P  < 0.001 and P  = 0.039, respectively). The height, width, and angle of the aortic arch were significantly larger in the aTBAD group (all P  < 0.05). Multivariable logistic regression showed that distal left common carotid artery diameter, aortic arch height, and ascending aorta tortuosity were associated with the occurrence of aTBAD. The area under the curve of the risk prediction model and the validation dataset were 0.8415 and 0.8319, respectively. The width, height, and angle of the ascending aorta and aortic arch were associated with the occurrence of aTBAD.
Magnetic resonance angiography derived predictors of progressive dilatation and surgery of the aortic root in Marfan syndrome
To identify magnetic resonance (MR) angiography derived predictors of progressive dilatation and surgery of the aortic root in Marfan syndrome. We retrospectively included 111 patients (32.7±16.5 years, range: 7-75 years) with a total of 446 MR angiographies. Aortic diameter growth rates of the entire thoracic aorta and Z-scores were estimated from annual diameter measurements. Aortic root shape was subdivided into three different types: (T0) normal; (T1) localized dilatation; (T2) generalized aortic root dilatation. Aortic diameter, Z-score, age, and aortic root shape at baseline were tested as predictors of aortic root dilatation using a multivariate logistic regression model. The highest aortic growth rate was observed at the level of the sinuses of Valsalva. Higher aortic root diameters and Z-scores at baseline predicted an increased growth of the aortic root (p = 0.003 and p<0.001). Young age (<30 years) was a predictor for the increase of Z-scores when compared to patients ≥30 years (p = 0.019). 25/111 patients (22.5%) had a T0 aortic root shape, 59/111 patients (53.2%) had a T1 aortic root shape, and 27/111 patients (24.3%) had a T2 aortic root shape. Aortic root shape did not predict further aortic growth (p>0.05). However, significantly more patients undergoing surgery had a generalized aortic dilatation (19/28, 76.9%) than a localized aortic root dilatation (9/28, 32.1%) (p = 0.001). Larger baseline aortic root diameter and Z-score as well as young age predict solely progressive aortic root dilatation in Marfan patients. MR angiography derived type of aortic root shape does not predict aortic growth, but patients with generalized aortic root dilatation are referred more frequently for aortic surgery.
Treatment of retrograde ascending aorta and aortic arch intramural hematoma (IMH) with thoracic endovascular aortic repair (TEVAR)
Typically, the presence of ascending aortic IMH is treated with open surgical repair due to the unpredictability of subsequent rupture. We demonstrate successful endovascular management of retrograde ascending IMH with TEVAR in a 58-year-old, high-risk patient. Assisted by high-quality pre- and intra-operative imaging, TEVAR for type B dissection with retrograde IMH extension into the ascending aorta may offer a less invasive treatment and possibly a better outcome for patients.
Normative computed tomography angiography values of the aortic root, aorta, and aortic arch in children
Normative values for intracardiac and extracardiac vascular structures help in understanding normal growth and changes over time in children; this normative data is not currently available for ECG-gated computed tomography angiography (CTA). We sought to establish ECG-gated CTA-derived normative values for the aortic root, aorta, and aortic arch in children. Aortic root, ascending aorta, aortic arch, and descending aorta were measured in systole and diastole in 100 subjects who had ECG-gated CTA at our center between January 2015 and December 2020 and met our inclusion criteria. The allometric exponent (AE) for each parameter was derived, and the parameter/body surface area AE (BSA AE ) was established using the previously described methods. Using this data, normalized mean, cross-sectional area, and standard deviation were calculated. Z -score curves were plotted in relation to the BSA for all measurements. Conclusion : Our study reports systolic and diastolic ECG-gated CTA Z -scores along with normative curves in relation to BSA for the aortic root, aorta, and aortic arch in children. What is Known: • Normative data for intracardiac and extracardiac vascular structures in the pediatric population are available for echocardiography, cardiac MRI and non-ECG gated CTA. • Z-scores with standard deviations are commonly used in children, but SDs are not constant across body sizes due to heteroscedasticity. What is New: • Allometric exponent was derived for each parameter and the parameter/body surface area (BSA) was established. • This is the first ECG-gated CTA study to provide normative en face systolic, diastolic diameters and cross-sectional areas along with Z-scores and normative curves for the aortic root, aorta and aortic arch in children.
Dynamic contrast-enhanced MRA of the aorta using a Golden-angle RAdial Sparse Parallel (GRASP) sequence: comparison with conventional time-resolved cartesian MRA (TWIST)
PurposeTo compare the application of two contrast-enhanced time-resolved magnetic resonance angiography sequences on an aortic disease patient cohort: the conventional Cartesian-sampling-based, Time-resolved angiography With Interleaved Stochastic Trajectories (TWIST) sequence, and the radial-sampling-based Golden-angle RAdial Sparse Parallel (GRASP) sequence. TWIST is highly sensitive to patient movement, which can lead to blurring and reduced sharpness of vascular structures, particularly in dynamic regions like the aorta. Such motion artifacts can compromise diagnostic accuracy. Radial-sampling-based techniques are less sensitive to motion than cartesian sampling and are expected to improve the image quality in body parts subjected to motion.Methods30 patients (60.9 ± 16.1y.o.) with various aortic diseases underwent a 1.5T magnetic resonance angiography examination. Assessment of image quality in the ascending aorta (AA), descending aorta (DA), and abdominal aorta (AbA) on a 4-point Likert scale (1 = excellent, 4 = non-diagnostic) as well as max. aortic diameters (Dmax) were performed. T-test and multilevel mixed-effect proportional-odds models were used for the image analysis.ResultsGRASP offered superior depiction of vascular structures in terms of vascular contrast for qualitative analysis (TWIST, reader 1: 1.6 ± 0.5; reader 2: 1.9 ± 0.4; reader 3: 1.1 ± 0.4; GRASP, reader 1: 1.5 ± 0.5; reader 2: 1.4 ± 0.5; reader 3: 1.0 ± 0.2) and vessel sharpness for qualitative (TWIST, reader 1: 1.9 ± 0.6; reader 2: 1.6 ± 0.6; reader 3: 2.0 ± 0.3; GRASP, reader 1: 1.4 ± 0.6; reader 2: 1.2 ± 0.4; reader 3: 1.3 ± 0.6) and quantitative analysis (TWIST, AA = 0.12 ± 0.04, DA = 0.12 ± 0.03, AbA = 0.11 ± 0.03; GRASP, AA = 0.20 ± 0.05, DA = 0.22 ± 0.06, AbA=0.20 ± 0.05). Streaking artefacts of GRASP were more visible compared to TWIST (TWIST, reader 1: 2.2 ± 0.6; reader 2: 1.9 ± 0.3; reader 3: 2.0 ± 0.5; GRASP, reader 1: 2.6 ± 0.6; reader 2: 2.3 ± 0.5; reader 3: 2.8 ± 0.6). Aortic Dmax comparison among the sequence showed no clinical relevance.ConclusionGRASP outperformed TWIST in SNR, vessel sharpness, and reduction in image blurring; streaking artefacts were stronger with GRASP, but did not affect diagnostic image quality.
Comparative Effectiveness of Intravascular Ultrasound Versus Angiography in Abdominal and Thoracic Endovascular Aortic Repair: Systematic Review and Meta-Analysis
The effectiveness of intravascular ultrasound (IVUS) with angiography compared with angiography guidance alone in treating aortic conditions, such as dissections, aneurysms, and blunt traumatic injuries, remains unclear. This systematic review and meta-analysis evaluates the current literature for IVUS use during thoracic endovascular aortic repair (TEVAR) and abdominal endovascular aortic repair (EVAR). A comprehensive search of MEDLINE, EMBASE, and Cochrane CENTRAL databases was conducted in March 2024 adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies comparing outcomes of TEVAR/EVAR with and without IVUS were identified. The outcomes of interest included contrast volume, fluoroscopy and procedural time, perioperative endoleak, and reinterventions and all-cause mortality during follow-up. Data with 95% confidence intervals (CIs) were extracted. Pooled analysis was performed using a random-effect model. Subgroup analysis was performed stratified by the condition being treated. Risk of bias was assessed using the Newcastle-Ottawa Scale for observational studies. A total of 4,219 patients (n = 2,655 IVUS and n = 1,564 non-IVUS) from 9 observational studies were included. The IVUS group exhibited a reduction in contrast agent volume (weighted mean difference −34.65 mL, 95% CI −54.73 to −14.57) and fluoroscopy time (weighted mean difference −6.13 minutes, 95% CI −11.10 to −1.15), with no difference in procedural time. The perioperative type I and III endoleak occurrences were similar (risk ratio 2.36, 95% CI 0.55 to 10.11; risk ratio 0.72, 95% CI 0.09 to 5.77, respectively). Reintervention and mortality during follow-up were comparable (hazard ratio 0.80, 95% CI 0.33 to 1.97; hazard ratio 0.75, 95% CI 0.47 to 1.18, respectively). All the included studies had small risks of bias. In conclusion, this meta-analysis provides evidence that IVUS enables the safe deployment of TEVAR/EVAR with reduced contrast agent and radiation exposure.
Agreement of Proximal Thoracic Aorta Size by Two-Dimensional Transthoracic Echocardiography and Magnetic Resonance Angiography
There is currently a lack of uniformity in methods of aortic diameter measurements across different imaging modalities. In this study, we sought to evaluate the accuracy of transthoracic echocardiography (TTE) in comparison with magnetic resonance angiography (MRA) for the measurement of proximal thoracic aorta diameters. This is a retrospective analysis of 121 adult patients at our institution who had TTE and electrocardiogram  (ECG)-gated MRA performed within 90 days of each other between 2013 and 2020. Measurements were made at the level of sinuses of Valsalva (SoV), sinotubular junction (STJ), and ascending aorta (AA) using leading edge–to–leading edge (LE) convention for TTE and inner-edge–to–inner-edge (IE) convention for MRA. Agreement was assessed using Bland-Altman methods. Intra- and interobserver variability were assessed by intraclass correlation. The average age of patients in the cohort was 62 years, and 69% of patients were male. The prevalence of hypertension, obstructive coronary artery disease, and diabetes was 66%, 20%, and 11%, respectively. The mean aortic diameter by TTE was SoV 3.8 ± 0.5 cm, STJ 3.5 ± 0.4 cm, and AA 4.1 ± 0.6 cm. The TTE-derived measurements were larger than the MRA ones by 0.2 ± 2 mm, 0.8 ± 2 mm, and 0.4 ± 3 mm at the level of SoV, STJ, and AA, respectively, but the differences were not statistically significant. There were no significant differences in the aorta measurements by TTE compared with MRA, when stratified by gender. In conclusion, transthoracic echocardiogram-derived proximal aorta measurements are comparable to MRA measurements. Our study validates current recommendations that TTE is an acceptable modality for screening and serial imaging of the proximal aorta.