The Usefulness of Magnetic Resonance Imaging of the Cardiovascular System in the Diagnostic Work-Up of Patients With Turner Syndrome

Abstract

Cardiovascular defects occur in 50% of patients with Turner syndrome (TS). The aim of the study was to estimate the usefulness of cardiac magnetic resonance imaging (CMR) and magnetic resonance angiography (angio-MR) as diagnostics in children and adolescents with TS. Forty-one females with TS, aged 13.9 ± 2.2 years, were studied. CMR was performed in 39 patients and angio-MR in 36. Echocardiography was performed in all patients. The most frequent anomalies diagnosed on CMR and angio-MR were as follows: elongation of the ascending aorta (AA) and aortic arch, present in 16 patients (45.7%), a bicuspid aortic valve (BAV), present in 16 patients (41.0%), and partial anomalous pulmonary venous return (PAPVR), present in six patients (17.1%). Aortic dilatation (Z-score > 2) was mostly seen at the sinotubular junction (STJ) (15 patients; 42.8%), the AA (15 patients; 42.8%), the thoracoabdominal aorta at the level of a diaphragm (15 patients; 42.8%), and the transverse segment (14 patients; 40.0%). An aortic size index (ASI) above 2.0 cm/m² was present in six patients (17.1%) and above 2.5 cm/m² in three patients (8.6%). The left ventricular end-diastolic volume (EDV), end-systolic volume (ESV), and stroke volume (SV) were diminished (Z-score < -2) in 10 (25.6%), 9 (23.1%), and 8 patients (20.5%), respectively. A webbed neck was correlated with the presence of vascular anomalies (p = 0.006). The age and body mass index (BMI) were correlated with the diameter of the aorta. Patients with BAV had a greater aortic diameter at the ascending aorta (AA) segment (p = 0.026) than other patients. ASI was correlated with aortic diameter and descending aortic diameter (AD/DD) ratio (p = 0.002; r = 0.49). There was a significant correlation between the right ventricular (p = 0.002, r = 0.46) and aortic diameters at the STJ segment (p = 0.0047, r = 0.48), as measured by echocardiography and CMR. Magnetic resonance can identify cardiovascular anomalies, dilatation of the aorta, pericardial fluid, and functional impairment of the ventricles not detected by echocardiography. BMI, age, BAV, and elongation of the AA influence aortic dilatation. The ASI and AD/DD ratio are important markers of aortic dilatation. The performed diagnostics did not indicate a negative influence of GH treatment on the cardiovascular system.

Keywords: MRI; Turner syndrome; cardiac magnetic resonance imaging; cardiovascular anomalies; girls; magnetic resonance angiography.

Figure 1

Locations of aortic diameter measurements: aortic sinus (AS), sinotubular junction (STJ), ascending aorta (AA), at the origin of the brachiocephalic artery (BCA), first transverse segment (T1), second transverse segment (T2), isthmic region (IR), descending aorta (DA), and the thoracoabdominal aorta at the level of the diaphragm (D).

Figure 2

Measurement of aortic diameter. Angio-MR (A,B), -perpendicular planes (C), -diameter of the ascending aorta in a transverse plane.

Figure 3

Protrusion of the aortic arch above the sternoclavicular joint. Distance between the highest point of the first transverse segment (T1) and the sternoclavicular joint (SCJ). (A) Angio-MR, coronal plane. SCJ (arrow); the perpendicular line shows the level of the SCJ. (B) Angio-MR, sagittal plane, showing the distance between the highest point of T1 and SCJ. Measurement the length of the aortic arch between the brachiocephalic trunk (BCT) and the left subclavian artery (LSA). (C) Measurements of the BCT, LCCA (left common carotid artery), and LSA were made on Angio-MR in a transverse plane. (D) Angio-MR of the aorta showing the spatial orientation of the arch and its branches (BCT, LCCA, LSA) and the measurement locations along the length of the aortic arch (black arrow). (E) Elongation of the ascending aorta. Distance between the aortic ring (AR) and the brachiocephalic trunk (BCT). Angio-MR, coronal plane.

Figure 4

Persistent left superior vena cava (PLSVC). 3D MRA. BCT, brachiocephalic trunk; LCCA, left common carotid artery; LSA, left subclavian artery.

Figure 5

Bovine arch. Left common carotid artery (LCCA) arising from the brachiocephalic trunk (BCT). 3D MRA. LSA, left subclavian artery.

Figure 6

Correlation between the ASI (aortic size index) >2 and AD/DD (aortic ascending/descending diameter) >1.5 (p = 0.015).