Cardiovascular magnetic resonance in patients with pectus excavatum compared with normal controls.

PURPOSE: To assess cardiothoracic structure and function in patients with pectus excavatum compared with control subjects using cardiovascular magnetic resonance imaging (CMR). METHOD: Thirty patients with pectus excavatum deformity (23 men, 7 women, age range: 14-67 years) underwent CMR using 1.5-Tesla scanner (Siemens) and were compared to 25 healthy controls (18 men, 7 women, age range 18-50 years). The CMR protocol included cardiac cine images, pulmonary artery flow quantification, time resolved 3D contrast enhanced MR angiography (CEMRA) and high spatial resolution CEMRA. Chest wall indices including maximum transverse diameter, pectus index (PI), and chest-flatness were measured in all subjects. Left and right ventricular ejection fractions (LVEF, RVEF), ventricular long and short dimensions (LD, SD), mid-ventricle myocardial shortening, pulmonary-systemic circulation time, and pulmonary artery flow were quantified. RESULTS: In patients with pectus excavatum, the pectus index was 9.3 ± 5.0 versus 2.8 ± 0.4 in controls (P < 0.001). No significant differences between pectus excavatum patients and controls were found in LV ejection fraction, LV myocardial shortening, pulmonary-systemic circulation time or pulmonary flow indices. In pectus excavatum, resting RV ejection fraction was reduced (53.9 ± 9.6 versus 60.5 ± 9.5; P = 0.013), RVSD was reduced (P < 0.05) both at end diastole and systole, RVLD was increased at end diastole (P < 0.05) reflecting geometric distortion of the RV due to sternal compression. CONCLUSION: Depression of the sternum in pectus excavatum patients distorts RV geometry. Resting RVEF was reduced by 6% of the control value, suggesting that these geometrical changes may influence myocardial performance. Resting LV function, pulmonary circulation times and pulmonary vascular anatomy and perfusion indices were no different to controls.

Peripheral contrast-enhanced MR angiography at 3.0T, improved spatial resolution and low dose contrast: initial clinical experience.

To investigate a high spatial resolution peripheral contrast-enhanced MR angiography (CE-MRA) protocol, applying a dedicated multi-channel array coil and accelerated parallel acquisition at 3.0T in evaluation of patients with peripheral vascular disease. Twenty patients with peripheral vascular disease underwent multi-station high spatial resolution peripheral CE-MRA at 3T. The image quality, presence of venous contamination, image noise, and artifact were evaluated by 2 radiologists independently. Assessment of arterial disease for 540 arterial segments was performed, and findings were correlated with conventional catheter angiography in 10 patients. All studies were yielded high diagnostic image quality. Venous contamination and artifact were minimal and never interfered with diagnosis. Sixty seven arterial segments with significant stenoses (>0%) were detected by observers with excellent interobserver agreement (kappa = 0.82; 95% CI: 0.76, 0.88). There was a significant correlation between CE-MRA and conventional angiography (Rs = 0.91 and 0.94 for reader 1 and 2, respectively) for the assessment of the degree of stenosis. Higher available SNR at 3T in combination with multi-coil technology and accelerated parallel acquisition, result in acquisition of nearly isotropic submillimeter 3D voxels throughout the entire peripheral arterial tree with diagnostic image quality and favorable comparative analysis with catheter angiography.