Serial Doppler velocimetry of mesenteric and portal flow in very-low-birth-weight preterm neonates with and without patent ductus arteriosus.

BACKGROUND: Very-low-birth-weight (VLBW) preterm neonates are vulnerable to patent ductus arteriosus (PDA), which might be related to high-resistance flow in the superior mesenteric artery (SMA), with decreased diastolic flow in situations of marked intestinal hypoperfusion. No previous studies have evaluated the portal vein and superior mesenteric vein (SMV) parameters to assess the PDA hemodynamic repercussions. OBJECTIVE: To assess mesenteric and portal flow in VLBW preterm neonates with or without PDA using serial Doppler ultrasonography (US). MATERIALS AND METHODS: We conducted a prospective longitudinal study on 61 VLBW preterm neonates submitted to 161 Doppler US exams, from 2 days to 20 days of age. RESULTS: All infants exhibited a progressive daily increase in the mean of the SMA diameter and systolic velocity, the portal vein diameter, the peak velocity, the mean velocity and the flow volume and of SMV diameter (P<0.05). The incidence of PDA was 37.7% (n=23) and infants with the disease revealed a smaller diameter, greater systolic velocity, lower diastolic velocity, and higher resistivity and pulsatility indices on SMA compared to those without PDA (P<0.05). Additionally, 47.8% (n=11) of infants with PDA exhibited absent or reversed end-diastolic flow in the SMA, and its resolution was seen among 54.5% (n=6) of these. Infants with PDA also exhibited lower values of portal vein diameter and flow volume and of SMV diameter (P<0.01). CONCLUSION: Doppler US enhances the understanding of mesenteric and portal flow, including the effects of PDA. The study of SMV and portal vein flow is proposed as a new parameter in PDA evaluation.

Waist circumference and mesenteric fat in neonates: negative correlation.

OBJECTIVE: To measure mesenteric fat thickness with ultrasound scan in neonates and to assess the correlation with waist circumference. METHODS: Ninety five healthy newborns had the maximum thickness of mesenteric leaves measured by ultrasound examinations of abdomen with an Envisor scanner (Philips Ultrasound, Bothell, Wash) and a L12-5 transducer (Philips Ultrasound). The correlation between the thickness of mesenteric leaves with abdominal waist was calculated. RESULTS: Maximum thickness of mesenteric leaves ranged from 0.24 to 1.00 mm (x = 0.57 ± 0.17) . There was a significant negative correlation between abdominal waist (AW) and mesenteric fat thickness (r = -0.384; p < 0.001). CONCLUSIONS: Mesenteric fat thickness in newborns is inversely associated with waist circumference. Higher visceral adiposity in neonates may be a protective mechanism from intrauterine growth restriction however this could persist into adulthood life.

Eliminating unenhanced CT when evaluating abdominal neoplasms in children.

OBJECTIVE: The purpose of our study was to evaluate a CT protocol that eliminates the unenhanced phase for imaging pediatric abdominal neoplasms. MATERIALS AND METHODS: We retrospectively performed a case series study of all the abdominal CT scans on children and adolescents found in our archives. Two radiologists separately evaluated each CT scan twice. The radiologists were separately asked to formulate the most probable diagnosis and to decide whether tumor calcification was present. The first evaluation was performed without the unenhanced phase and the second was done with both the unenhanced and the contrast-enhanced scans. The agreement between the two methods, and that between each method and the histopathologic results, were measured using kappa statistics. The sensitivity and specificity of each method for diagnosing the more frequent neoplasms were also measured. The sensitivity and specificity of the contrast-enhanced CT scans were assessed for detecting calcification without reference to the unenhanced scan. RESULTS: A total of 131 CT scans were evaluated. The agreement between diagnoses from the two methods was almost perfect for both radiologists (kappa = 0.97 and 0.99). No statistically significant difference was seen between the two methods and the histopathologic results. The sensitivity and specificity of the two methods for the most frequent neoplasms were similar. The evaluations without the unenhanced phase showed good sensitivity and specificity for tumor calcifications. CONCLUSION: CT protocols without the unenhanced phase are a viable alternative for evaluating abdominal neoplasms in children and adolescents.

The aurora sign in a patient with type B Niemann-Pick disease.

The aurora sign, a sonographic sign found on the sagittal and transverse view, refers to multiple bands of ring-down artifacts posterior to the right hemidiaphragm. Parenchymal lung disease should be suspected when this is present. We report a case of type B Niemann-Pick disease with pulmonary involvement and the aurora sign on abdominal sonography. High-resolution CT of the chest showed corresponding thickened interlobular septa.