In vivo MR-angiography for the assessment of aortic aneurysms in an experimental mouse model on a clinical MRI scanner: Comparison with high-frequency ultrasound and histology.

BACKGROUND: MR-angiography currently represents one of the clinical reference-standards for the assessment of aortic-dimensions. For experimental research in mice, dedicated preclinical high-field MRI scanners are used in most studies. This type of MRI scanner is not available in most institutions. The aim of this study was to evaluate the potential of MR-angiography performed on a clinical MR scanner for the assessment of aortic aneurysms in an experimental mouse model, compared to a preclinical high-resolution ultrasound imaging system and histopathology. METHODS: All in vivo MR imaging was performed with a clinical 3T MRI system (Philips Achieva) equipped with a clinical gradient system in combination with a single-loop surface-coil (47 mm). All MR sequences were based on clinically used sequences. For ultrasound, a dedicated preclinical high-resolution system (30 MHz linear transducer, Vevo770, VisualSonics) was used. All imaging was performed with an ApoE knockout mouse-model for aortic aneurysms. Histopathology was performed as reference-standard at all stages of aneurysm development. RESULTS: MR-angiography on a clinical 3T system enabled the clear visualization of the aortic lumen and aneurysmal dilation at different stages of aneurysm development. A close correlation (R2 = 0.98; p < 0.001) with histological area measurements was found. Additionally, a good agreement between MR and ultrasound area measurements in systole (R2 = 0.91; p < 0.001) and diastole (R2 = 0.94; p < 0.001) were measured. Regarding interobserver reproducibility, MRI measurements yielded a smaller 95% confidence interval and a closer interreader correlation compared to ultrasound measurements (-0.37-0.46; R2 = 0.97 vs. -0.78-0.88; R2 = 0.87). CONCLUSION: This study demonstrates that MR-angiography, performed on a clinical 3T MR scanner, enables the reliable detection and quantification of the aortic dilatation at different stages of aneurysm development in an experimental mouse model.

Echocardiography screening of siblings of children with bicuspid aortic valve.

BACKGROUND AND OBJECTIVE: Left heart defects, such as bicuspid aortic valve (BAV), are heritable. Consensus guidelines have recommended echocardiographic screening of first-degree relatives. The utility of this approach in siblings of children with BAV is not known. The objective of this study is to evaluate the yield of routine screening of siblings of children with BAV and undertake an economic analysis of this practice. METHODS: Siblings of children with BAV who underwent echocardiographic screening in a single pediatric cardiology practice were identified. The anatomic features and hemodynamics of siblings newly diagnosed with BAV were recorded. A Markov model was constructed to determine cost-effectiveness ratios, and sensitivity analyses were performed. RESULTS: There were 207 screened siblings of 181 children with BAV. The median age at screening was 7 years. BAV was identified in 21 (10.1%) of siblings screened. The median peak Doppler gradient was 18 mm Hg. Aortic insufficiency was mild or less in all. The mean cost to diagnose BAV in a sibling was $2109 per new case found. The estimated mean cost to avert a single aortic dissection in the third or fourth decade of life was $363 911. The estimated cost per life-year saved was $74 884 and ranged from $17 461 to $1 136 536 in sensitivity analysis. CONCLUSIONS: Echo screening among siblings of those with BAV is effective and inexpensive and may lower the risk of the complications of such as dissection, although it comes at a moderate cost relative to benefits gained. Screening of siblings should be incorporated into clinical care.

[Acute aortic syndromes: an assessment]. / Il punto sulle sindromi aortiche acute.

The term "acute aortic syndrome" describes a range of severe, painful, potentially life-threatening abnormalities of the aorta. This review discusses the pathophysiology and risk factors, classification schemes, epidemiology, clinical presentations, diagnostic modalities, management options, and outcomes of various aortic conditions, including acute aortic dissection (AD) and its variants intramural hematoma and penetrating atherosclerotic ulcer. The common denominator of acute aortic syndromes is disruption of the media layer of the aorta, with bleeding within the layers (intramural hematoma), along the aortic media resulting in separation of the layers (AD), or transmurally through the wall in the case of ruptured penetrating atherosclerotic ulcer or trauma. The incidence of AD ranges from 2 to 3.5 cases per 100 000 person-years; hypertension and a variety of genetic disorders with altered connective tissues are the most prevalent risk conditions. Recent advances in imaging techniques have helped in understanding the natural history and dynamics of this condition. Prognosis is clearly related to undelayed diagnosis and appropriate surgical repair in case of proximal involvement of the aorta; the advent of endovascular treatment has opened new perspectives in the management of acute aortic syndromes affecting the descending aorta, since this can modify its natural history and improve prognosis.

A genealogical assessment of heritable predisposition to aneurysms.

OBJECT: This study was conducted to investigate the familial and genetic contribution to intracranial, abdominal aortic, and all other types of aneurysms, and to define familial relationships among patients who present with the different aneurysm types. METHODS: The authors used a unique Utah resource to perform population-based analysis of the familial nature of aneurysms. The Utah Population Data Base is a genealogy of the Utah population dating back eight generations, which is combined with death certificate data for the state of Utah dating back to 1904. Taking into account the genetic relationships among all aneurysm cases derived from this resource, the authors used a previously published method to estimate the familiality of different aneurysm types. Using internal, birth-cohort-specific rates of disease calculated from the database, they estimated relative risks by comparing observed to expected rates of aneurysm incidence in defined sets of relatives of probands. CONCLUSIONS: Each of the three aneurysm types investigated showed significant evidence for a genetic component. Relatives of patients with intracranial aneurysms do not appear to be at increased risk for abdominal or other lesions, but relatives of patients with abdominal aortic aneurysms appear to be at increased risk for other types of these lesions.