Differential Effect of the Ratio of Right Ventricular Volume to Left Ventricular Volume in Children with Repaired Tetralogy of Fallot.

We aimed to compare the diagnostic value of indexed right ventricular end-diastolic volume (RVEDVi) and the ratio of right ventricle volume to left ventricle volume (RV/LV ratio) in prediction of the severity of pulmonary regurgitation (PR) expressed as the PR fraction (PRF) after surgery of tetralogy of Fallot (TOF). Forty-one patients with repaired TOF were included in the study. RVEDVi, LVEDVi, RV/LV ratio, PRF and ejection fraction were measured with magnetic resonance imaging. A PRF of more than 20% was considered significant. The predictive capability of two markers (RVEDVi and RV/LV ratio) for significant PR was compared using multivariate linear regression analysis and receiver operating characteristic (ROC) analysis. Both the RV/LV ratio and RVEDVi showed a correlation with PRF (r = 0.526/0.321, p = 0.001/0.041) in the correlation analysis, but in multivariate regression analysis the only independent predictor of PRF was the RV/LV ratio (F = 14.890, p = 0.001). ROC analysis revealed that a better discrimination of significant PR (>20%) from slight types (=20%) PR can be reached with the RV/LV ratio than RVEDVi (AUC = 0.805/0.709, p = 0.01). The RV/LV ratio was better than RVEDVi at differentiating mild from moderate PR (p = 0.006 vs. p = 0.153), and proved superior over RVEDVi in predicting PR based on the PRF criterion.

[Preliminary application of magnetic resonance susceptibility weighted imaging in neonates with punctate white matter lesions].

OBJECTIVE: To evaluate the severity of punctate white matter lesions (PWML) in neonatal brain injury with susceptibility weighted imaging (SWI) and explore the value and limitation of SWI versus the conventional magnetic resonance imaging (MRI). METHODS: A total of 34 neonates presenting with PWML at initial MRI were recruited for this prospective study. PWML were defined as punctuate lesions with T(1) hyperintensity and T(2) isointensity or hypointensity in white matter. There were 21 males and 13 females with a median age of 9.24 days (range: 2 - 17 days). All MRI examinations were performed at 1.5 Tesla unit including conventional MRI (T(1), T(2) & Flair sequences), DWI and SWI. PWML were classified into two groups: (1) T(1) hyperintensity & T(2) isointensity; (2) T(1) hyperintensity & T(2) hypointensity. The manifestations of PWML on SWI were analyzed. RESULTS: Among all cases, only 5 cases (14.7%) demonstrated an evidence of hemorrhage on SWI. There were 7 cases in Group 1. Only 1 case showed punctate hypointensity in the areas of PWML on SWI while there was no hemorrhage on SWI in other 6 cases. Twenty-seven cases were in Group 2. Only 4 cases showed an evidence of hemorrhage on SWI while hemorrhage was absent on SWI in other 23 cases. CONCLUSION: Most areas of PWML in neonatal brain show no hemorrhage on SWI. And SWI can help to identify whether or not hemorrhage is present in PWML of neonates.