Coarctation of the aorta: pre and postoperative evaluation with MRI and MR angiography; correlation with echocardiography and surgery

Computed Tomographic Evaluation of Congenital Left Ventricular Outflow Obstruction

Congenital left ventricular outflow obstruction represents a multilevel obstruction with several morphological forms. It can involve the subvalvular, valvar, or supravalvular portion of the aortic valve complex, and may coexist. Computed tomography (CT) plays an important supplementary role in the evaluation of patients with congenital LVOT obstruction. Unlike transthoracic echocardiography and cardiovascular magnetic resonance (CMR) imaging, it is not bounded by a small acoustic window, needs for anaesthesia or sedation, and metallic devices. Current generations of CT scanners with excellent spatial and temporal resolution, high pitch scanning, wide detector system, dose reduction algorithms, and advanced 3-dimensional postprocessing techniques provide a high-quality alternative to CMR or diagnostic cardiac catheterization. Radiologists performing CT in young children should be familiar with the advantages and disadvantages of CT and with the typical morphological imaging features of congenital left ventricular outflow obstruction.

Society for Cardiovascular Magnetic Resonance/European Society of Cardiovascular Imaging/American Society of Echocardiography/Society for Pediatric Radiology/North American Society for Cardiovascular Imaging Guidelines for the use of cardiovascular magnetic resonance in pediatric congenital and acquired heart disease : Endorsed by The American Heart Association

Cardiovascular magnetic resonance (CMR) has been utilized in the management and care of pediatric patients for nearly 40 years. It has evolved to become an invaluable tool in the assessment of the littlest of hearts for diagnosis, pre-interventional management and follow-up care. Although mentioned in a number of consensus and guidelines documents, an up-to-date, large, stand-alone guidance work for the use of CMR in pediatric congenital 36 and acquired 35 heart disease endorsed by numerous Societies involved in the care of these children is lacking. This guidelines document outlines the use of CMR in this patient population for a significant number of heart lesions in this age group and although admittedly, is not an exhaustive treatment, it does deal with an expansive list of many common clinical issues encountered in daily practice.

Society for Cardiovascular Magnetic Resonance/European Society of Cardiovascular Imaging/American Society of Echocardiography/Society for Pediatric Radiology/North American Society for Cardiovascular Imaging Guidelines for the Use of Cardiac Magnetic Resonance in Pediatric Congenital and Acquired Heart Disease: Endorsed by The American Heart Association

Cardiovascular magnetic resonance has been utilized in the management and care of pediatric patients for nearly 40 years. It has evolved to become an invaluable tool in the assessment of the littlest of hearts for diagnosis, pre-interventional management and follow-up care. Although mentioned in a number of consensus and guidelines documents, an up-to-date, large, stand-alone guidance work for the use of cardiovascular magnetic resonance in pediatric congenital 36 and acquired 35 heart disease endorsed by numerous Societies involved in the care of these children is lacking. This guidelines document outlines the use of cardiovascular magnetic resonance in this patient population for a significant number of heart lesions in this age group and although admittedly, is not an exhaustive treatment, it does deal with an expansive list of many common clinical issues encountered in daily practice.

Diagnosis of Congenital Coarctation of the Aorta and Accompany Malformations in Infants by Multi-Detector Computed Tomography Angiography and Transthoracic Echocardiography: A Chinese Clinical Study

Background

The purpose of this study was to evaluate the utility of multi-detector computed tomography (MDCT) angiography and transthoracic echocardiography (TTE) in the diagnosis of congenital coarctation of the aorta (CoA) and accompanying malformations in infants.

Material/Methods

From January 2012 and December 2015, we enrolled 68 infants with clinically suspected CoA who underwent MDCT angiography and TTE in our hospital. Surgical correction was conducted to confirm the diagnostic accuracy of both examinations in all patients.

Results

In this study, the diagnosis of CoA was confirmed infants by surgical results in 55 of 68 infants. The diagnostic accuracy, sensitivity, and specificity of MDCT angiography were 95.6%, 96.4%, and 92.3%, respectively. The diagnostic accuracy, sensitivity, and specificity of TTE were 88.2%, 90.9%, and 76.9%, respectively. There was no significant difference in diagnostic accuracy, sensitivity, and specificity between MDCT angiography and TTE (χ²=2.473, p>0.05, χ²=1.373, p>0.05 and χ²=1.182, p>0.05, respectively). In the diagnosis of concomitant cardiac abnormalities with CoA, the 2 methods also play different roles.

Conclusions

MDCT angiography and TTE play different roles in the diagnosis of CoA and accompany malformations. MDCT angiography in the diagnosis of the extra-cardiac vascular malformations is better than TTE, and TTE is superior to MDCT angiography in diagnosing intracardiac malformation. Combined MDCT angiography and TTE is a relatively valuable, reliable, and noninvasive method in the diagnosis of CoA and accompany malformations in infants.

Preoperative Use of CT Angiography in Infants With Coarctation of the Aorta

Background:

Computed tomographic angiography (CTA) and echocardiography (echo) are used preoperatively in coarctation of the aorta to define arch hypoplasia and great vessel branching. We sought to determine differences in quantitative measurements, as well as surgical utility, between modalities.

Methods:

Infants (less than six months) with both CTA and echo prior to coarctation repair from 2004 to 2013 were included. Measurements were compared and correlated with surgical approach. Three surgeons reviewed de-identified images to predict approach and characterize utility. Computed tomographic angiography radiation dose was calculated.

Results:

Thirty-three patients were included. No differences existed in arch measurements between echo and CTA ( z-score: −2.59 vs −2.43; P = .47). No differences between modalities were seen for thoracotomy ( z-score: −2.48 [echo] vs −2.31 [CTA]; P = .48) or sternotomy ( z-score: −3.13 [echo] vs −3.08 [CTA]; P = .84). Computed tomographic angiography delineated great vessel branching pattern in two patients with equivocal echo findings ( P = .60). Surgeons rated CTA as far more useful than echo in understanding arch hypoplasia and great vessel branching in cases where CTA was done to resolve anatomical questions that remain after echo evaluation. Two of three surgeons were more likely to choose the surgical approach taken based on CTA (surgeon A, P = .02; surgeon B, P = .01). Radiation dose averaged 2.5 (1.6) mSv and trended down from 2.9 mSv (1.8 mSv; n = 20) to 1.6 mSv (0.5 mSv; n = 7) ( P = .06) with new technology.

Conclusion:

Although CTA and echo measurements of the aorta do not differ, CTA better delineates branching and surgeons strongly prefer it for three-dimensional arch anatomy. We recommend CTA for patients with anomalous arch branching patterns, diffuse or complex hypoplasia, or unusual arch morphology not fully elucidated by echo.

Sudden cardiac death from structural heart diseases in adults: imaging findings with cardiovascular computed tomography and magnetic resonance

Sudden cardiac death (SCD) is defined as the unexpected natural death from a cardiac cause within an hour of the onset of symptoms in the absence of any other cause. Although such a rapid course of death is mainly attributed to a cardiac arrhythmia, identification of structural heart disease by cardiovascular computed tomography (CCT) and cardiovascular magnetic resonance (CMR) imaging is important to predict the long-term risk of SCD. In adults, SCD most commonly results from coronary artery diseases, coronary artery anomalies, inherited cardiomyopathies, valvular heart diseases, myocarditis, and aortic dissection with coronary artery involvement or acute aortic regurgitation. This review describes the CCT and CMR findings of structural heart diseases related to SCD, which are essential for radiologists to diagnose or predict.

Multimodality imaging of aortic coarctation: From the fetus to the adolescent

Aortic coarctation is a local narrowing of the aortic lumen, which is located at the level of the isthmus in 95% of patients. Aortic coarctation accounts for 5 to 8% of all congenital heart diseases. It may have an acute presentation in the form of heart failure in the neonate or may be discovered incidentally in adult because of severe treatment-resistant hypertension. Ultrasound may reveal the presence of aortic coarctation during the antenatal period. In this situation, associated abnormalities should be investigated (including karyotype), because they influence prognosis and indicates whether or not the birth should occur in a center with pediatric cardiology expertise. Postnatally, ultrasound and chest radiography are the basic imaging work-up. Computed tomography is often the second line imaging investigation in infants and young children for whom magnetic resonance imaging fails to confirm the diagnosis. Magnetic resonance imaging with cardiac synchronization is the preferred imaging tool in the post-treatment period. Aortic coarctation may be treated surgically or by endovascular techniques. Potential complications should be searched for using ultrasound and magnetic resonance imaging.

Coarctation of the Aorta: Strategies for Improving Outcomes

Coarctation of the aorta is a common congenital heart defect through which management has rapidly evolved over the last few decades. The role of transcatheter-based therapies is expanding and seems to be an effective treatment option for coarctation, especially in adults. Patients with prior coarctation repair are at risk of long-term complications related to prior surgeries and associated congenital heart defects, in particular, the risk of restenosis and aortic aneurysm development related to the timing and mode of prior intervention. This article outlines the evaluation and management of adults with unrepaired coarctation and patients after coarctation repair.

CT and MRI of aortic coarctation: pre- and postsurgical findings

OBJECTIVE. The purpose of this article is to summarize the roles of CT and MRI in the diagnosis and follow-up of patients with aortic coarctation. CONCLUSION. Aortic coarctation is a common congenital heart disease accounting for approximately 6-8% of congenital heart defects. Despite its deceptively simple anatomic presentation, it is a complex medical problem with several associated anatomic and physiologic abnormalities. CT and MRI may provide very accurate information of the coarctation anatomy and other associated cardiac abnormalities.

Assessing and addressing cardiovascular risk in adults with Turner syndrome

Turner syndrome (TS), the result of a structurally abnormal or absent X chromosome, occurs in one in 2 000 live born females. The phenotype is highly variable, but short stature and gonadal dysgenesis are usually present. The main objective in adults with TS is health surveillance, but TS still causes a reduction in life expectancy of up to 13 years, with cardiovascular disease, congenital or acquired, as the major cause of an early death. While it has been established that all women with TS should undergo in-depth cardiovascular examination at diagnosis, advice on the cardiovascular management of women with TS is limited. Here, we provide a summary of our current practice within a multidisciplinary team, supported by our expertise in various aspects of cardiovascular risk management, and the evidence from research where it is available, with the aim of providing optimal support to our patients with TS.

BACKGROUND

A dedicated Adult Turner Clinic was established in South East Scotland in 2002. This gynaecology-led clinic serves a population of roughly 1·2 million and, currently, reviews around 50 women with TS annually. Referrals for adult care come from paediatrics or general practice. Following a series of individual case discussions regarding the management of more complex cardiovascular problems, we have assembled a dedicated multidisciplinary group to determine a timely cardiovascular screening strategy, a basis for specialist referral, and appropriate hypertension management. This team now includes a paediatric endocrinologist, gynaecologist, cardiologist (with an interest in inherited disorders), vascular radiologist and hypertension specialist. Here, we review the literature on cardiovascular disease in women with TS and, make recommendations, based on relatively limited high-quality evidence, together with our experience, on the optimal timing of cardiovascular screening.

Imaging of thoracic aortic disease

Aortic pathology can be more complex to understand on imaging than is initially appreciated. There are a number of imaging modalities that provide excellent assessment of aortic pathology and enable the accurate monitoring of disease. This review discusses the imaging of the most common disease processes that affect the aorta in adults, with the primary focus being on CT and MRI.

Usefulness of cardiovascular magnetic resonance imaging to predict the need for intervention in patients with coarctation of the aorta

Cardiovascular magnetic resonance (CMR) imaging can predict hemodynamically significant coarctation of the aorta (CoA) with a high degree of discrimination. However, the ability of CMR to predict important clinical outcomes in this patient population is unknown. Therefore, we sought to define the ability of CMR to predict the need for surgical or transcatheter intervention in patients with CoA. We retrospectively reviewed the data from 133 consecutive patients who had undergone CMR for the evaluation of known or suspected CoA. The characteristics of the CMR-derived variables predicting the need for surgical or transcatheter intervention for CoA within 1 year were determined through logistic regression analysis. Therapeutic aortic intervention was performed in 41 (31%) of the 133 patients during the study period. The indexed minimum aortic cross-sectional area was the strongest predictor of subsequent intervention (area under the receiver operating characteristic curve 0.975) followed by heart rate-corrected deceleration time in the descending aorta (area under the receiver operating characteristic curve 0.951), and the percentage of flow increase (area under the receiver operating characteristic curve 0.867). The combination of the indexed minimum aortic cross-sectional area and rate-corrected deceleration time in the descending aorta provided the best predictive model (area under the receiver operating characteristic curve 0.986). In conclusion, CMR findings can predict the need for subsequent intervention in CoA. These findings reinforce the "gate-keeper role" of CMR to cardiac catheterization by providing valuable diagnostic and powerful prognostic information and could guide additional treatment of patients with CoA with the final intent of reducing the number of diagnostic catheterizations in such patients.

Prediction of hemodynamic severity of coarctation by magnetic resonance imaging

A published formula containing minimal aortic cross-sectional area and the flow deceleration pattern in the descending aorta obtained by cardiovascular magnetic resonance predicts significant coarctation of the aorta (CoA). However, the existing formula is complicated to use in clinical practice and has not been externally validated. Consequently, its clinical utility has been limited. The aim of this study was to derive a simple and clinically practical algorithm to predict severe CoA from data obtained by cardiovascular magnetic resonance. Seventy-nine consecutive patients who underwent cardiovascular magnetic resonance and cardiac catheterization for the evaluation of native or recurrent CoA at Children's Hospital Boston (n = 30) and the University of California, San Francisco (n = 49), were retrospectively reviewed. The published formula derived from data obtained at Children's Hospital Boston was first validated from data obtained at the University of California, San Francisco. Next, pooled data from the 2 institutions were analyzed, and a refined model was created using logistic regression methods. Finally, recursive partitioning was used to develop a clinically practical prediction tree to predict transcatheter systolic pressure gradient ≥ 20 mm Hg. Severe CoA was present in 48 patients (61%). Indexed minimal aortic cross-sectional area and heart rate-corrected flow deceleration time in the descending aorta were independent predictors of CoA gradient ≥ 20 mm Hg (p <0.01 for both). A prediction tree combining these variables reached a sensitivity and specificity of 90% and 76%, respectively. In conclusion, the presented prediction tree on the basis of cutoff values is easy to use and may help guide the management of patients investigated for CoA.

Endovascular management of coarctation of the aorta

Untreated thoracic aortic coarctation leads to early death predominantly because of hypertension and its cardiovascular sequelae. Surgical treatment has been available for > 50 years and has improved hypertension and survival. More recently, endovascular techniques have offered a minimally invasive alternative to traditional open repair. Early and intermediate results suggest angioplasty and stenting have an important role in the management of aortic coarctation, particularly in adults and older children.

Magnetic resonance imaging findings in Loeys-Dietz syndrome

Loeys-Dietz syndrome is a newly described entity characterised by a constellation of arterial tortuosity, cranial malformations, and hypertelorism. We report a case of a 7-year old boy with confirmed Loeys-Dietz syndrome and discuss magnetic resonance imaging as a complete technique for assessment and follow-up of aggressive vascular pathology in the brain, thorax, and abdomen, which may dictate early surgical intervention.

Normal values for aortic diameters in children and adolescents--assessment in vivo by contrast-enhanced CMR-angiography

BACKGROUND

Contrast-enhanced CMR angiography (CE-CMRA) is being increasingly used for diagnosing aortic arch anomalies, planning interventions and follow-up assessment. We sought to establish normal values for the diameters of the thoracic aorta and reference curves related to body growth in children using CE-CMRA.

RESULTS

CE-CMRA was performed in 53 children without cardiovascular disease. The median age was 9 years (range 2 - 20 years), weight 30 kg (range 12 - 75 kg), height 131 cm (range 81 - 184 cm), body surface area (BSA) 1.05 m2 (range 0.52-1.9 m2). Aortic diameters were measured at nine standardized sites on oblique maximum-intensity projection (MIP) images. Regression analysis of diameters in relation to BSA demonstrated linear relationship between the cross-sectional aortic diameters and the square root of BSA (BSA0.5). Normative diameters were (0.57 + 19.37*BSA0.5) mm for the aortic sinus, (-3.52 + 18.66*BSA0.5) mm for the first segment of the aortic arch, (-3.37 + 16.52*BSA0.5) mm for the isthmic region and (-1.27 + 9.89*BSA0.5) mm for the descending aorta at the level of the diaphragm. Normative curves are presented.

CONCLUSION

This study provides normative values for aortic diameters in children measured by CE-CMRA. These data may serve for making the diagnosis of pediatric arch anomalies, assessing the need for treatment and planning interventions.

Contrast-enhanced MR angiography of thoracic vascular malformations in children

To plan an effective management of thoracic vascular malformations, clinicians must have a clear understanding of the anatomy. Although echocardiography and angiography are the leading imaging modalities in patients with congenital cardiovascular anomalies, magnetic resonance (MR) imaging and computed tomography (CT) are valuable noninvasive adjuncts. MR imaging and CT are effective in demonstrating the complex extracardiac morphology and yield helpful information that can change the treatment plan. Although recent reports state the usefulness of multidetector CT (MDCT), in terms of pediatric population, the significance of radiation exposure should be taken into account. Thus, contrast enhanced MR angiography, as a guide in planning surgery, seems to be the best alternative to conventional angiography in the diagnosis of congenital vascular malformations. In this review, the diagnostic features of thoracic vascular malformations in pediatric population are discussed, and, the potential uses of contrast-enhanced MR angiography are emphasized with the retrospective evaluation of imaging findings in 114 examinations.

Comparison of different MRI techniques for the assessment of thoracic aortic pathology: 3D contrast enhanced MR angiography, turbo spin echo and balanced steady state free precession

PURPOSE

The purpose of this study was to compare two non-contrast 2D techniques with the current contrast-enhanced MRI standard 3D technique for the routine assessment of thoracic aortic pathologies.

METHODS

One hundred patients with suspected or known thoracic aortic diseases were examined with a 1.5 T scanner using 2D turbo spin echo (TSE), 2D balanced steady state free precession (balanced SSFP) and 3D contrast-enhanced MR angiography (CE-MRA). The diameters of the aorta at predefined levels were measured. The feasibility to visualize the aortic root and supra-aortic branches was tested. All morphologic abnormalities of the aorta, the aortic wall and the aortic valve, as well as image quality of TSE and balanced SSFP influencing the diagnosis were analysed.

RESULTS

Compared to CE-MRA, balanced SSFP and TSE allowed for the detection of a significantly higher number of relevant pathologies (thickened aortic wall and signs of emergency) in less time. No significant differences were found among the sequences for the identification of aneurysms, dissection membranes and thrombi. No single technique was able to address all clinically relevant issues. TSE was associated with a better image quality compared to balanced SSFP, which however did not translate into a significantly improved diagnostic accuracy.

CONCLUSION

The total number of pathologic findings was higher using 2D TSE and balanced SSFP when compared to 3D CE-MRA. None of the techniques applied could address all clinically relevant issues. The major drawback of TSE is its relatively long scanning time while balanced SSFP is associated with more artifacts.