Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 77
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Artículo en Inglés | MEDLINE | ID: mdl-32178922

RESUMEN

OBJECTIVE: Current guidelines for elective surgery of ascending thoracic aortic aneurysms (aTAAs) use aneurysm size as primary determinant for risk stratification of adverse events. Biomechanically, dissection may occur when wall stress exceeds wall strength. Determining patient-specific aTAA wall stresses by finite element analysis can potentially predict patient-specific risk of dissection. This study compared peak wall stresses in patients with ≥5.0 cm versus <5.0 cm aTAAs to determine correlation between diameter and wall stress. METHODS: Patients with aTAA ≥5.0 cm (n = 47) and <5.0 cm (n = 53) were studied. Patient-specific aneurysm geometries obtained from echocardiogram-gated computed tomography were meshed and prestress geometries determined. Peak wall stresses and stress distributions were determined using LS-DYNA finite element analysis software (LSTC Inc, Livermore, Calif), with user-defined fiber-embedded material models under systolic pressure. RESULTS: Peak circumferential stresses at systolic pressure were 530 ± 83 kPa for aTAA ≥5.0 cm versus 486 ± 87 kPa for aTAA <5.0 cm (P = .07), whereas peak longitudinal stresses were 331 ± 57 kPa versus 310 ± 54 kPa (P = .08), respectively. For aTAA ≥5.0 cm, correlation between peak circumferential stresses and size was 0.41, whereas correlation between peak longitudinal wall stresses and size was 0.33. However, for aTAA <5.0 cm, correlation between peak circumferential stresses and size was 0.23, whereas correlation between peak longitudinal stresses and size was 0.14. CONCLUSIONS: Peak patient-specific aTAA wall stresses overall were larger for ≥5.0 cm than aTAA <5.0 cm. Although some correlation between size and peak wall stresses was found in aTAA ≥5.0 cm, poor correlation existed between size and peak wall stresses in aTAA <5.0 cm. Patient-specific wall stresses are particularly important in determining patient-specific risk of dissection for aTAA <5.0 cm.

2.
Ann Thorac Surg ; 2020 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-32006475

RESUMEN

BACKGROUND: Bicuspid aortic valve-associated ascending thoracic aortic aneurysms (BAV-aTAAs) carry a risk of acute type A dissection. Biomechanically, dissection may occur when wall stress exceeds wall strength. Our aim was to develop patient-specific computational models of BAV-aTAAs to determine magnitudes of wall stress by anatomic regions. METHODS: Patients with BAV-aTAA diameter greater than 4.5 cm (n = 41) underwent electrocardiogram-gated computed tomography angiography. Three-dimensional aneurysm geometries were reconstructed after accounting for prestress and loaded to systemic pressure. Finite element analyses were performed with fiber-embedded hyperelastic material model using LS-DYNA software (LSTC Inc, Livermore, CA) to obtain wall stress distributions. The 99th percentile longitudinal and circumferential stresses were determined at systole. RESULTS: The 99th percentile longitudinal wall stresses for BAV-aTAAs at sinuses of Valsalva, sinotubular junction (STJ), and ascending aorta were 361 ± 59.8 kPa, 295 ± 67.2 kPa, and 224 ± 37.6 kPa, respectively, with significant differences in ascending aorta vs sinuses (P< 1 × 10-13) and STJ (P < 1 × 10-6). The 99th percentile circumferential wall stresses were 474 ± 88.2 kPa, 634 ± 181.9 kPa, and 381 ± 54.0 kPa for sinuses, the STJ, and the ascending aorta, respectively, with significant differences in the ascending aorta vs sinuses (P = .002) and STJ (P < 1 × 10-13). CONCLUSIONS: Wall stresses, both circumferential and longitudinal, were greater in the aortic root, sinuses, and STJ than in the ascending aorta on BAV-aTAAs. These results fill a fundamental knowledge gap regarding biomechanical stress distribution in BAV-aTAA patients, which when related to wall strength may provide prognostication of aTAA dissection risk by patient-specific modeling.

3.
Radiology ; 294(3): 707-713, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31990263

RESUMEN

Background Intraluminal thrombus (ILT) within abdominal aortic aneurysms (AAAs) may be a potential marker for subsequent aneurysm growth. Purpose To investigate the role of ILT in AAA progression as assessed with CT and MRI. Materials and Methods This was a retrospective study, with patient data included from January 2004 to December 2018 at a Veteran Affairs medical center. Male patients with AAA who underwent contrast material-enhanced CT at baseline and CT or black-blood MRI at follow-up (minimal follow-up duration of 6 months) were included. The maximal AAA diameter was measured with multiplanar reconstruction, and the annual growth rate of aneurysms was calculated. Uni- and multivariable linear regression analyses were used to determine the relationship between demographic and imaging factors and aneurysm growth. Results A total of 225 patients (mean age, 72 years ± 9 [standard deviation]) were followed for a mean of 3.3 years ± 2.5. A total of 207 patients were followed up with CT, and 18 were followed up with MRI. At baseline, the median size of the AAA was 3.8 cm (interquartile range [IQR], 3.3-4.3 cm); 127 of 225 patients (54.7%) had ILT. When compared with AAAs without ILT, AAAs with ILT had larger baseline diameters (median, 4.1 cm [IQR, 3.6-4.8 cm] vs 3.4 cm [IQR, 3.2-3.9 cm]; P < .001) and faster growth rates (median, 2.0 mm/y [IQR, 1.3-3.2 mm/y] vs 1.0 mm/y [IQR, 0.4-1.8 mm/y]; P < .001). Small AAAs (size range, 3-4 cm) with ILT grew 1.9-fold faster than did those without ILT (median, 1.5 mm/y [IQR, 0.9-2.7 mm/y] vs 0.8 mm/y [IQR, 0.3-1.5 mm/y]; P < .001). Medium AAAs (size range, 4-5 cm) with ILT had 1.2-fold faster growth than did those without ILT (median growth, 2.1 mm/y [IQR, 1.4, 3.7 mm/y] vs 1.8 mm/y [IQR, 0.9, 2.0 mm/y]; P = .06). In multivariable analysis, baseline diameter and ILT were independently positively related to aneurysm growth rate (standardized regression coefficient, 0.43 [P < .001] and 0.15 [P = .02], respectively). Conclusion Both maximal cross-sectional aneurysm diameter and the presence of intraluminal thrombus are independent predictors of abdominal aortic aneurysm growth. © RSNA, 2020 Online supplemental material is available for this article.

4.
Radiol Clin North Am ; 58(1): 93-103, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31731905

RESUMEN

This article describes an approach to analyzing the distribution of intravenous contrast on chest computed tomography and illustrates the various pathologies and pitfalls that may be encountered by the imager, especially in the hospitalized patient. Understanding normal and abnormal distribution of intravenous contrast can be used as a clue to detect alterations in physiology and flow.


Asunto(s)
Medios de Contraste , Cardiopatías/diagnóstico por imagen , Pacientes Internos , Embolia Pulmonar/diagnóstico por imagen , Intensificación de Imagen Radiográfica , Tomografía Computarizada por Rayos X/métodos , Corazón/diagnóstico por imagen , Hospitalización , Humanos , Pulmón/diagnóstico por imagen , Radiografía Torácica/métodos
5.
Nat Rev Cardiol ; 2019 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-31819230

RESUMEN

Mitral regurgitation (MR) is a common valvular heart disease and is the second most frequent indication for heart valve surgery in Western countries. Echocardiography is the recommended first-line test for the assessment of valvular heart disease, but cardiovascular magnetic resonance imaging (CMR) provides complementary information, especially for assessing MR severity and to plan the timing of intervention. As new CMR techniques for the assessment of MR have arisen, standardizing CMR protocols for research and clinical studies has become important in order to optimize diagnostic utility and support the wider use of CMR for the clinical assessment of MR. In this Consensus Statement, we provide a detailed description of the current evidence on the use of CMR for MR assessment, highlight its current clinical utility, and recommend a standardized CMR protocol and report for MR assessment.

6.
JAMA Netw Open ; 2(11): e1915828, 2019 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-31747036

RESUMEN

Importance: Positron emission tomography-computed tomography (PET-CT) has been increasingly used in the management of lung cancer, but its association with survival has not been convincingly documented. Objective: To examine the association of the use of PET-CT with non-small cell lung cancer (NSCLC) mortality in the US Department of Veterans Affairs (VA) health care system from 2000 to 2013. Design, Setting, and Participants: This cohort study included 64 103 veterans receiving care in the VA health care system who were diagnosed with incident NSCLC between September 2000 and December 2013. Data analysis took place in October 2018. Exposure: Use of PET-CT before and/or after diagnosis. Main Outcomes and Measures: All-cause and NSCLC-specific 5-year mortality; secondary outcome was receipt of stage-appropriate treatment. Results: A total of 64 103 veterans with the diagnosis of NSCLC were evaluated; 62 838 (98.0%) were men, and 50 584 (78.9%) were white individuals. Among these, 51 844 (80.9%) had a PET-CT performed: 25 735 (40.1%) in the 12 months before diagnosis and 41 242 (64.3%) in the 5 years after diagnosis. Increased PET-CT use (597 of 978 veterans [59.2%] in 2000 vs 3649 of 3915 [93.2%] in 2013) and decreased NSCLC-specific 5-year mortality (879 of 978 veterans [89.9%] in 2000 vs 3226 of 3915 veterans [82.4%] in 2013) were found over time. Increased use of stage-appropriate therapy was also seen over time, from 346 of 978 veterans (35.4%) in 2000 to 2062 of 3915 (52.7%) in 2013 (P < .001). Increased PET-CT use was associated with higher-complexity level VA facilities (26 127 veterans [82.3%] at level 1a vs 1289 [75.2%] at level 3 facilities; P < .001) and facilities with on-site PET-CT compared with facilities without on-site PET-CT (33 081 [82.2%] vs 17 443 [80.3%]; P < .001). Use of PET-CT before diagnosis was associated with increased likelihood of stage-appropriate treatment for all stages of NSCLC (eg, veterans with stage 1 disease: 4837 of 7870 veterans [61.5%] who received PET-CT underwent surgical resection vs 4042 of 7938 veterans [50.9%] who did not receive PET-CT; P < .001) and decreased mortality in a risk-adjusted model among all participants and among veterans undergoing stage-appropriate treatment (all-cause mortality: hazard ratio [HR], 0.78; 95% CI, 0.77-0.79; NSCLC-specific mortality: HR, 0.78; 95% CI, 0.76-0.80). Facilities with on-site PET-CT and higher-complexity level facilities were associated with a mortality benefit, with 16% decreased mortality at level 1a vs level 3 facilities (HR, 0.84; 95% CI, 0.80-0.89) and a 3% decrease in all-cause mortality in facilities with on-site PET-CT (HR, 0.97; 95% CI, 0.96-0.99). Conclusions: In this study, the use of PET-CT among veterans with NSCLC significantly increased from 2000 to 2013, coinciding with decreased 5-year mortality and an increase in stage-appropriate treatment. Variation in use of PET-CT was found, with the highest use at higher-complexity level facilities and those with PET-CT on-site. These facilities were associated with reduced all-cause and NSCLC-specific mortality.

7.
Radiology ; 293(3): 554-564, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31638489

RESUMEN

Background Ferumoxytol is approved for use in the treatment of iron deficiency anemia, but it can serve as an alternative to gadolinium-based contrast agents. On the basis of postmarketing surveillance data, the Food and Drug Administration issued a black box warning regarding the risks of rare but serious acute hypersensitivity reactions during fast high-dose injection (510 mg iron in 17 seconds) for therapeutic use. Whereas single-center safety data for diagnostic use have been positive, multicenter data are lacking. Purpose To report multicenter safety data for off-label diagnostic ferumoxytol use. Materials and Methods The multicenter ferumoxytol MRI registry was established as an open-label nonrandomized surveillance databank without industry involvement. Each center monitored all ferumoxytol administrations, classified adverse events (AEs) using the National Cancer Institute Common Terminology Criteria for Adverse Events (grade 1-5), and assessed the relationship of AEs to ferumoxytol administration. AEs related to or possibly related to ferumoxytol injection were considered adverse reactions. The core laboratory adjudicated the AEs and classified them with the American College of Radiology (ACR) classification. Analysis of variance was used to compare vital signs. Results Between January 2003 and October 2018, 3215 patients (median age, 58 years; range, 1 day to 96 years; 1897 male patients) received 4240 ferumoxytol injections for MRI. Ferumoxytol dose ranged from 1 to 11 mg per kilogram of body weight (≤510 mg iron; rate ≤45 mg iron/sec). There were no systematic changes in vital signs after ferumoxytol administration (P > .05). No severe, life-threatening, or fatal AEs occurred. Eighty-three (1.9%) of 4240 AEs were related or possibly related to ferumoxytol infusions (75 mild [1.8%], eight moderate [0.2%]). Thirty-one AEs were classified as allergiclike reactions using ACR criteria but were consistent with minor infusion reactions observed with parenteral iron. Conclusion Diagnostic ferumoxytol use was well tolerated, associated with no serious adverse events, and implicated in few adverse reactions. Registry results indicate a positive safety profile for ferumoxytol use in MRI. © RSNA, 2019 Online supplemental material is available for this article.

9.
J Biomech Eng ; 2019 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-31253989

RESUMEN

Intraluminal thrombus (ILT) is present in the majority of abdominal aortic aneurysms (AAA) of a size warranting consideration for surgical or endovascular intervention. The rupture risk of AAAs is thought to be related to the balance of vessel wall strength and the mechanical stress caused by systemic blood pressure. Previous finite element analyses of AAAs have shown that ILT can reduce and homogenize aneurysm wall stress. These works have largely considered ILT to be homogeneous in mechanical character or have idealized a stiffness distribution through the thrombus thickness. In this work, we use MRI to delineate the heterogeneous composition of ILT in 7 AAAs and perform patient-specific finite element analysis under multiple conditions of ILT layer stiffness disparity. We find that explicit incorporation of ILT heterogeneity in the finite element analysis is unlikely to substantially alter major stress analysis predictions regarding aneurysm rupture risk in comparison to models assuming a homogenous thrombus, provided that the maximal ILT stiffness is the same between models. Our results also show that under a homogeneous ILT assumption, the choice of ILT stiffness from values common in the literature can result in significantly larger variations in stress predictions compared to the effects of thrombus heterogeneity.

10.
J Magn Reson Imaging ; 50(3): 994-1001, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30694008

RESUMEN

BACKGROUND: Intraluminal thrombus (ILT) signal intensity on MRI has been studied as a potential marker of abdominal aortic aneurysm (AAA) progression. PURPOSE: 1) To characterize the relationship between ILT signal intensity and AAA diameter; 2) to evaluate ILT change over time; and 3) to assess the relationship between ILT features and AAA growth. STUDY TYPE: Prospective. SUBJECTS: Eighty AAA patients were imaged, and a subset (n = 41) were followed with repeated MRI for 16 ± 9 months. FIELD STRENGTH/SEQUENCE: 3D black-blood fast-spin-echo sequence at 3 T. ASSESSMENT: ILT was designated as "bright" if the signal was greater than 1.2 times that of adjacent psoas muscle. AAAs were divided into three groups based on ILT: Type 1: bright ILT; Type 2: isointense ILT; Type 3: no ILT. During follow-up, an active ILT change was defined as new ILT formation or an increase in ILT signal intensity to bright; stable ILT was defined as no change in ILT type or ILT became isointense from bright previously. STATISTICAL TESTS: Shapiro-Wilk test; Mann-Whitney U-test; Fisher's exact test; Kruskal-Wallis test; Spearman's r; intraclass correlation coefficient (ICC), Cohen's kappa. RESULTS: AAAs with Type 1 ILT were larger than those with Types 2 and 3 ILT (5.1 ± 1.1 cm, 4.4 ± 0.9 cm, 4.2 ± 0.8 cm, P = 0.008). The growth rate of AAAs with Type 1 ILT was significantly greater than that of AAAs with Types 2 and 3 ILT (2.6 ± 2.5, 0.6 ± 1.3, 1.5 ± 0.6 mm/year, P = 0.01). During follow-up, AAAs with active ILT changes had a 3-fold increased growth rate compared with AAAs with stable ILT (3.6 ± 3.0 mm/year vs. 1.2 ± 1.5 mm/year, P = 0.008). DATA CONCLUSION: AAAs with bright ILT are larger in diameter and grow faster. Active ILT change is associated with faster AAA growth. Black-blood MRI can characterize ILT features and monitor their change over time, which may provide new insights into AAA risk assessment. LEVEL OF EVIDENCE: 2 Technical Efficacy Stage: 5 J. Magn. Reson. Imaging 2019;50:994-1001.

12.
J Thorac Cardiovasc Surg ; 156(2): 473-480, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-30011756

RESUMEN

Bicuspid aortic valve disease is a common congenital cardiac disorder, being present in 1% to 2% of the general population. Associated aortopathy is a common finding in patients with bicuspid aortic valve disease, with thoracic aortic dilation noted in approximately 40% of patients in referral centers. Several previous consensus statements and guidelines have addressed the management of bicuspid aortic valve-associated aortopathy, but none focused entirely on this disease process. The current document is an executive summary of "The American Association for Thoracic Surgery Guidelines on Bicuspid Aortic Valve-Related Aortopathy." All major aspects of bicuspid aortic valve aortopathy, including natural history, phenotypic expression, histology and molecular pathomechanisms, imaging, indications for surgery, surveillance, and follow-up, and recommendations for future research are contained within these guidelines. The current executive summary serves as a condensed version of the guidelines to provide clinicians with a current and comprehensive review of bicuspid aortic valve aortopathy and to guide the daily management of these complex patients.


Asunto(s)
Enfermedades de la Aorta , Enfermedades de las Válvulas Cardíacas , Cirugía Torácica , Válvula Aórtica/anomalías , Humanos , Estados Unidos
13.
J Thorac Cardiovasc Surg ; 156(2): e41-e74, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-30011777

RESUMEN

Bicuspid aortic valve disease is the most common congenital cardiac disorder, being present in 1% to 2% of the general population. Associated aortopathy is a common finding in patients with bicuspid aortic valve disease, with thoracic aortic dilation noted in approximately 40% of patients in referral centers. Several previous consensus statements and guidelines have addressed the management of bicuspid aortic valve-associated aortopathy, but none focused entirely on this disease process. The current guidelines cover all major aspects of bicuspid aortic valve aortopathy, including natural history, phenotypic expression, histology and molecular pathomechanisms, imaging, indications for surgery, surveillance, and follow-up, and recommendations for future research. It is intended to provide clinicians with a current and comprehensive review of bicuspid aortic valve aortopathy and to guide the daily management of these complex patients.


Asunto(s)
Válvula Aórtica/anomalías , Enfermedades de las Válvulas Cardíacas , Adolescente , Adulto , Anciano , Enfermedades de la Aorta , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/fisiopatología , Válvula Aórtica/cirugía , Procedimientos Quirúrgicos Cardíacos , Niño , Diagnóstico por Imagen , Femenino , Enfermedades de las Válvulas Cardíacas/diagnóstico por imagen , Enfermedades de las Válvulas Cardíacas/fisiopatología , Enfermedades de las Válvulas Cardíacas/cirugía , Humanos , Masculino , Persona de Mediana Edad , Estados Unidos , Adulto Joven
14.
Tomography ; 4(1): 26-32, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30042984

RESUMEN

Subclinical systolic and diastolic left ventricular (LV) dysfunction has been reported in previous echocardiographic studies on congenital bicuspid aortic valve (BAV). Patients with BAV commonly undergo evaluation with magnetic resonance imaging, and feature-tracking cardiovascular magnetic resonance (CMR-FT) is an emerging technique that assesses myocardial strain using standard cine sequences. This study investigated differences in myocardial strain between patients with BAV with preserved ejection fraction (EF) and controls using CMR-FT. Patients with isolated BAV and preserved EF, who had previously undergone CMR (n = 42; mean age, 41.2 ± 13.9) were compared with controls (n = 19; 36.6 ± 9.8; P = .2). Investigational CMR-FT strain analysis software was used to measure circumferential systolic and diastolic strain values, as well as standard LV volumetric and functional parameters. The majority of patients with BAV had mild or no valve dysfunction, and LV myocardial mass end-diastolic volume indices were similar between groups. Peak diastolic circumferential strain rate was lower in patients with BAV than in controls (0.89 ± 0.27 vs 1.21 ± 0.21 s-1, P = .003). After adjusting for covariates, only myocardial mass index was independently associated with peak circumferential systolic strain and diastolic strain rate. Feature-tracking CMR can identify abnormalities of LV strain in a clinical cohort of asymptomatic patients with BAV with preserved EF. Decreases in circumferential diastolic strain rate in patients with BAV suggest evidence of early diastolic dysfunction.

16.
J Thorac Cardiovasc Surg ; 156(2): 492-500, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-29656820

RESUMEN

OBJECTIVE: Guidelines for repair of bicuspid aortic valve-associated ascending thoracic aortic aneurysms have been changing, most recently to the same criteria as tricuspid aortic valve-ascending thoracic aortic aneurysms. Rupture/dissection occurs when wall stress exceeds wall strength. Recent studies suggest similar strength of bicuspid aortic valve versus tricuspid aortic valve-ascending thoracic aortic aneurysms; thus, comparative wall stress may better predict dissection in bicuspid aortic valve versus tricuspid aortic valve-ascending thoracic aortic aneurysms. Our aim was to determine whether bicuspid aortic valve-ascending thoracic aortic aneurysms had higher wall stresses than their tricuspid aortic valve counterparts. METHODS: Patients with bicuspid aortic valve- and tricuspid aortic valve-ascending thoracic aortic aneurysms (bicuspid aortic valve = 17, tricuspid aortic valve = 19) greater than 4.5 cm underwent electrocardiogram-gated computed tomography angiography. Patient-specific 3-dimensional geometry was reconstructed and loaded to systemic pressure after accounting for prestress geometry. Finite element analyses were performed using the LS-DYNA solver (LSTC Inc, Livermore, Calif) with user-defined fiber-embedded material model to determine ascending thoracic aortic aneurysm wall stress. RESULTS: Bicuspid aortic valve-ascending thoracic aortic aneurysms 99th-percentile longitudinal stresses were 280 kPa versus 242 kPa (P = .028) for tricuspid aortic valve-ascending thoracic aortic aneurysms in systole. These stresses did not correlate to diameter for bicuspid aortic valve-ascending thoracic aortic aneurysms (r = -0.004) but had better correlation to tricuspid aortic valve-ascending thoracic aortic aneurysms diameter (r = 0.677). Longitudinal stresses on sinotubular junction were significantly higher in bicuspid aortic valve-ascending thoracic aortic aneurysms than in tricuspid aortic valve-ascending thoracic aortic aneurysms (405 vs 329 kPa, P = .023). Bicuspid aortic valve-ascending thoracic aortic aneurysm 99th-percentile circumferential stresses were 548 kPa versus 462 kPa (P = .033) for tricuspid aortic valve-ascending thoracic aortic aneurysms, which also did not correlate to bicuspid aortic valve-ascending thoracic aortic aneurysm diameter (r = 0.007). CONCLUSIONS: Circumferential and longitudinal stresses were greater in bicuspid aortic valve- than tricuspid aortic valve-ascending thoracic aortic aneurysms and were more pronounced in the sinotubular junction. Peak wall stress did not correlate with bicuspid aortic valve-ascending thoracic aortic aneurysm diameter, suggesting diameter alone in this population may be a poor predictor of dissection risk. Our results highlight the need for patient-specific aneurysm wall stress analysis for accurate dissection risk prediction.


Asunto(s)
Aneurisma de la Aorta Torácica , Válvula Aórtica/anomalías , Enfermedades de las Válvulas Cardíacas , Anciano , Aneurisma de la Aorta Torácica/diagnóstico por imagen , Aneurisma de la Aorta Torácica/epidemiología , Aneurisma de la Aorta Torácica/fisiopatología , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/fisiología , Válvula Aórtica/fisiopatología , Fenómenos Biomecánicos/fisiología , Angiografía por Tomografía Computarizada , Electrocardiografía , Análisis de Elementos Finitos , Enfermedades de las Válvulas Cardíacas/diagnóstico por imagen , Enfermedades de las Válvulas Cardíacas/epidemiología , Enfermedades de las Válvulas Cardíacas/fisiopatología , Humanos , Persona de Mediana Edad , Modelos Cardiovasculares , Estudios Retrospectivos
19.
Int J Cardiovasc Imaging ; 34(3): 475-483, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28905233

RESUMEN

Both noncontrast and contrast-enhanced approaches to gated thoracic magnetic resonance angiography (MRA) for aortic root evaluation have been reported at 3T. We compare qualitative and quantitative image quality measures for the two approaches, and assess the reproducibility of standard aortic measurements. Respiratory and cardiac gated MRA of the chest was performed at 3T in 45 patients: 23 after administration of iron-based blood pool contrast, and 22 without contrast. Image quality was assessed with a 5-point Likert scale, vessel lumen-to-muscle contrast ratios, and vessel wall sharpness. Two reviewers measured the ascending aorta diameter and valve annulus area. Interrater agreement was assessed using Bland-Altman plots and coefficient of variation (CV). Qualitative image quality was better with blood pool contrast in all principal vessels of the chest (mean Likert of 4.20 ± 0.79 vs. 2.60 ± 0.77, p < 0.001). Quantitative assessment was also improved with higher contrast ratios in all vessels (5.26 ± 3.3 vs. 1.90 ± 0.53, p < 0.001), and greater sharpness of the aortic annulus and ascending aorta (0.70 ± 0.16 vs. 0.56 ± 0.14 mm-1, p < 0.001, and 0.87 ± 0.16 vs. 0.62 ± 0.16 mm-1, p = 0.008, respectively). Reproducibility of measurement was marginally better for the ascending aorta diameter (CV of 2.80 vs. 3.23%), but substantially increased for the aortic valve annulus area with blood pool contrast (CV of 4.93 vs. 7.32%). The use of a blood pool contrast agent for gated thoracic MRA improves image quality compared to a noncontrast technique, and provides more reproducible measurements of the aortic valve annulus area.


Asunto(s)
Aorta Torácica/diagnóstico por imagen , Válvula Aórtica/diagnóstico por imagen , Aortografía/métodos , Técnicas de Imagen Sincronizada Cardíacas , Medios de Contraste/administración & dosificación , Óxido Ferrosoférrico/administración & dosificación , Angiografía por Resonancia Magnética/métodos , Anciano , Anciano de 80 o más Años , Electrocardiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Estudios Retrospectivos
20.
Int J Cardiovasc Imaging ; 34(2): 273-279, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28884401

RESUMEN

To evaluate the effect of MRI blood pool contrast agent on 4D flow image quality and ventricular volume measurements. Adult patients referred for clinical cardiac MRI (n = 22) were imaged with 4D flow. Patients with renal failure (n = 10) received ferumoxytol, and the remainder (n = 12) received gadofosveset trisodium. Image quality was assessed with (1) signal-to-noise ratio (SNR); (2) contrast-to-noise ratio (CNR); and (3) 5-point Likert scale based on endocardial border definition (1 = none; 2 = partial but unable to visualize; 3 = able to roughly estimate; 4 = visible for most of the cardiac cycle; 5 = excellent definition). A subset (n = 15) had short axis steady-state free precession (SSFP) cine imaging allowing for comparison of standard volumetric measurement technique with 4D flow derived volumetric measurements. 4D flow studies using ferumoxytol demonstrated a higher median Likert score of 5 (IQR, 5-5) versus 3 (IQR, 2-3). Median cavity SNR and CNR were higher for ferumoxytol compared to gadofosveset trisodium [65 (IQR, 50-74) versus 22 (IQR, 14-28), p < 0.001; and 40 (IQR, 32-49) versus 4 (IQR, 3-10), p < 0.001]. Good correlation (p < 0.001) was seen between SSFP and 4D flow measured ventricular volumes (ESV and EDV) with ferumoxytol (r = 0.998, mean difference = 1.2 mL, LOA = - 7.7-10.1 mL) and gadofosveset trisodium (r = 0.942, mean difference = - 2.7 mL, LOA = - 35.7-27.1 mL). Ferumoxytol used off-label as an MRI blood pool contrast agent offers an attractive alternative to gadofosveset trisodium in patients with renal failure, with excellent 4D flow image quality and good correlation of volumetric measurements compared to the CMR reference (SSFP).


Asunto(s)
Óxido Ferrosoférrico/administración & dosificación , Gadolinio/administración & dosificación , Cardiopatías/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Compuestos Organometálicos/administración & dosificación , Adulto , Anciano , Anciano de 80 o más Años , Circulación Coronaria , Femenino , Óxido Ferrosoférrico/efectos adversos , Gadolinio/efectos adversos , Cardiopatías/complicaciones , Cardiopatías/fisiopatología , Humanos , Imagen por Resonancia Magnética/efectos adversos , Masculino , Persona de Mediana Edad , Compuestos Organometálicos/efectos adversos , Valor Predictivo de las Pruebas , Estudios Prospectivos , Insuficiencia Renal/complicaciones , Insuficiencia Renal/diagnóstico , Insuficiencia Renal/fisiopatología , Reproducibilidad de los Resultados , Factores de Riesgo , Volumen Sistólico , Función Ventricular Izquierda , Función Ventricular Derecha
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA