Visual liver assessment using Gd-EOB-DTPA-enhanced magnetic resonance imaging of patients in the early post-Fontan period.

No imaging modality can be used to evaluate Fontan-associated liver disease (FALD). We retrospectively reviewed hepatic gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (EOB-MRI) characteristics of patients within 1 year post-Fontan procedure, and we evaluated the association between hepatic imaging abnormalities and clinical parameters, including follow-up cardiac catheterization and laboratory test findings. The EOB-MR images were graded, based on the extent of the decreased enhancement, as "normal" (Grade 1), "segmental" (Grade 2), "regional" (Grade 3), and "diffuse" (Grade 4). We enrolled 37 patients (mean age, 3.5 ± 1.0 years): 9 patients had Grade 1 or 2; 14 patients, Grade 3; and 14 patients, Grade 4. EOB-MRI revealed characteristic reticular or mosaic patterns of diminished enhancement (i.e. "frog spawn" appearance). Ultrasonography did not detect diminished enhancement or "frog spawn" appearance. A trend existed toward increased grade severity in imaging with increased central venous pressure, pulmonary vascular resistance, and gamma-glutamyltransferase levels. Noninvasive EOB-MRI revealed the characteristic pattern of diminished enhancement, which was correlated with certain clinical parameters indicative of Fontan physiology and liver dysfunction. Early-stage FALD may occur soon after the Fontan procedure and is associated with increased pressure in the inferior vena cava and hepatic veins.

Noninvasive assessment of left ventricular contractility in pediatric patients using the maximum rate of pressure rise in peripheral arteries.

The maximum rate of left ventricular pressure rise (LV dp/dt(max)) is a good indicator of ventricular contractility. However, its measurement requires invasive cardiac catheterization. By applying the relationship between the ratio of aorta (Ao) dp/dt(max) to LV dp/dt(max) and the mean artery pressure (MAP), we tested the possible noninvasive estimation of LV dp/dt(max) by the maximum rate of pressure rise in peripheral arteries, as measured by tonometry. The study subjects were 31 children with cardiovascular disease. The LV and Ao pressures were measured during cardiac catheterization, with simultaneous recording of the brachial (BrA) or radial (RaA) artery pressure. The relationships between BrA dp/dt(max) and Ao dp/dt(max) and between RaA dp/dt(max) and Ao dp/dt(max) were determined (Ao dp/dt(max) = 0.299 × BrA dp/dt(max) + 210.6, n = 17, r = 0.78, SEE = 74.0, P = 0.0002, and Ao dp/dt(max) = 1.442 × RaA dp/dt(max) + 165.9, n = 14, r = 0.87, SEE = 66.1, P = 0.0001). Using these relationships and the equation Ao dp/dt(max)/LV dp/dt(max) = 0.694 - 4.00 × 10(-3) × MAP, LV dp/dt(max) was estimated from BrA dp/dt(max) or RaA dp/dt(max). The estimated LV dp/dt(max) correlated well with the measured LV dp/dt(max) independent of the site of measurement (y = 0.912 × x + 112.9, r = 0.91, P < 0.0001). Furthermore, there was excellent correlation between the measured and estimated LV dp/dt(max) after changes in contractility with dobutamine in 10 randomly selected patients (y = 0.86 × x + 34.2, r = 0.77, P = 0.01). It is possible to estimate LV dp/dt(max) noninvasively in children using tonometry. This procedure can be useful for bedside assessment of LV contractility and the clinical management of patients with cardiovascular disease.