Three-dimensional rotational angiography in the assessment of vascular and airway compression in children after a cavopulmonary anastomosis.

The aim of the study was to examine the role of three-dimensional rotational angiography (3DRA) in assessing vascular and airway narrowing in children with a bidirectional cavopulmonary anastomosis (BCPA). The course of children with single ventricle physiology is often complicated by left pulmonary artery (LPA) and/or bronchial stenosis and may be related to aortic compression. 3DRA may be useful in evaluating this complex anatomy and possible mechanisms for the observed obstruction. Clinical data and imaging (2D angiography and 3DRA) of children with a BCPA were reviewed retrospectively. Measurements were taken at similar locations along the pulmonary arteries in both modalities and in the airways on 3DRA. Twenty-five children with a previous BCPA were assessed at mean age of 3.1 ± 2.0 years and weight of 13.6 ± 3.6 kg. Excellent correlation was found between 3DRA and 2D angiographic LPA measurements (r = 0.89, p < 0.0001). Twelve children had qualitative LPA stenosis on 3DRA, with a stenotic dimension of 6.6 ± 2.2 mm on 2D angiography and 6.8 ± 1.9 mm on 3DRA (r = 0.94, p < 0.0001). Ten cases with LPA stenosis also had bronchial stenosis (83 %). Qualitative airway assessment correlated with quantitative bronchial dimensions from 3DRA-derived tomographic images: Bronchial stenosis measured 4.4 ± 1.6 versus 5.9 ± 1.1 mm in those with a normal appearing bronchus (p = 0.009). Hybrid patients (initial palliation with bilateral pulmonary artery banding and arterial ductal stenting, n = 5) and all patients with a Damus-Kaye-Stansel (DKS) anastomosis (n = 9) were more likely to have LPA and left bronchial stenosis (OR 7.7, p = 0.04). 3DRA is a useful and accurate tool in assessment of LPA and airway narrowing after BCPA. Hybrid and DKS patients are more prone to LPA and bronchial stenosis, and 3DRA can provide insight into the mechanism.

Pulmonary artery pulsatility and effect on vessel diameter assessment in magnetic resonance imaging.

BACKGROUND: Information about thoracic vascular sizes can crucially affect clinical decision-making in cardiovascular disease. A variety of imaging techniques such as catheter angiography, contrast enhanced computed tomography (CT) and cardiac magnetic resonance imaging (CMR) are routinely used to measure vascular diameters. Traditionally, CMR black blood sequences were the main anatomical tool for visualization of vascular anatomy and still are in many centers. More recently, the vessel diameters are measured on multiplanar reconstructions derived from static magnetic resonance angiography (MRA). This study was performed to investigate the variation of vessel diameter measurements on different CMR techniques with respect to their data acquisition scheme. METHODS: We recruited two groups of patients for this prospective study. One group included patients with repaired tetralogy of Fallot (TOF), with at least moderate pulmonary insufficiency and another group of patients who underwent CMR as part of a diagnostic work-up for arrhythmogenic right ventricular cardiomyopathy (ARVC). Additional images of the right pulmonary artery (RPA) were acquired in the double inversion recovery (DIR) black blood, cine steady state free precession (SSFP) and MRA. All images were reviewed by two CMR trained readers using the electronic caliper provided within the picture archiving and communication system package. The maximum diameter of each artery was recorded in millimeters with up to one decimal point. Paired t-tests and Bland-Altman plots were used for comparison of measurements between different sequences. RESULTS: A total of 52 patients were recruited for this study, 26 patients in the TOF group (15 males, age 12.55±2.9) and 26 patients in the ARVC group (15 males, age 15.6±2.3). In both groups, the RPA sizes were not significantly different between the DIR images and diastolic cine SSFP (p>0.05). Measurements on DIR were significantly smaller than those made on systolic cine SSFP or MRA in both groups (p<0.0001). Vessel diameters measured on systolic SSFP were significantly larger than measurements made on diastolic SSFP (p<0.0001). There was no significant difference between vessel measurements on MRA and measurements on systolic cine SSFP (p=0.44 for the TOF group and p=0.79 for ARVC group). Measurements on the MRA datasets were significantly larger than those on diastolic SSFP images (p<0.0001). CONCLUSION: Black blood, white blood and MRA sequences are all reproducible CMR methods for the assessment of arterial diameters in children and adolescents. Measurements from systolic phase SSFP images are comparable to those from contrast-enhanced MRA. Therefore, the administration of contrast medium is not necessary in every case. Cine SSFP images offer the additional advantage over the other methods in such that both the largest and the smallest diameter of the vessel during the cardiac cycle can be assessed using this technique. This is even more relevant in highly pulsatile circulations, such as patients with repaired TOF and significant pulmonary insufficiency.

Assessment of fetal pulmonic stenosis by ultrasonography.

This study was designed to determine (1) the value of Doppler echocardiography in depicting the presence of a fetal pulmonary stenosis, (2) its reliability in the assessment of the severity of the lesion, and (3) the usefulness of additional markers from the left side of the heart as criteria of severity. Fourteen pregnant ewes were included in this study (gestational age, 90 to 120 days). Banding of the fetal main pulmonary artery created mild (n = 3), moderate (n = 3), and severe (n = 5) stenosis. Three lambs were sham operated. Intrauterine fetal Doppler echocardiographic data obtained 15 days after surgery were compared with preoperative values. Peak velocities recorded through the band increased linearly from baseline in the groups with mild and moderate stenosis but did not show any further increase in the group with severe stenosis. Compared with the sham-operated group, right ventricular output in the group with stenosis was either similar or reduced significantly. The increase in right ventricular free wall thickness was significantly greater in the groups with stenosis compared with that of the sham-operated group; the correlation with the degree of severity was r = 0.65 and p < 0.05. A A stronger positive correlation was found between the severity of stenosis and aortic valve diameters: r = 0.82 and p < 0.01. The strongest correlation was found for right ventricular/left ventricular outputs (r = 0.92; p < 0.001). Thus Doppler peak velocities through the obstruction can help detect pulmonic stenosis but are not reliable for the assessment of its severity during fetal life. Other ultrasound measurements such as the size of the aortic anulus and especially the ratio of right ventricular/left ventricular output could be used as sensitive markers of the severity of stenosis.

Cardiologic abnormalities in Noonan syndrome: phenotypic diagnosis and echocardiographic assessment of 118 patients.

OBJECTIVES: The purpose of this study was to determine the incidence of cardiologic abnormalities in Noonan syndrome. BACKGROUND: The incidence of cardiac abnormalities in Noonan syndrome remains unknown, largely because of such difficulties as assembling a substantial cohort, ensuring a correct phenotypic diagnosis and providing accurate definitions of the most frequent abnormalities--pulmonary stenosis and left ventricular hypertrophy. METHODS: A cohort of 145 patients was assembled, and before cardiologic assessment two independent geneticists scrutinized the phenotype. The diagnosis was confirmed in 118 patients, and they were studied by two-dimensional and Doppler echocardiography. RESULTS: A dysplastic pulmonary valve was present in eight patients (7%) and was associated with significant stenosis in six (75%) of the eight. Significant stenosis was present in 22 (20%) of 110 patients without dysplasia. Left ventricular hypertrophy was present in 29 patients (25%) without significant pulmonary stenosis. Localized anterior septal hypertrophy was the most common pattern in 12 (41%) of 29 patients. Diffuse hypertrophy involving the entire septum and the free wall was present in nine patients (31%) and was severe (> 1.7 cm) in five. Other abnormalities included secundum atrial septal defects (10%). CONCLUSIONS: The high incidence of cardiac abnormalities suggests that echocardiographic and Doppler evaluation of patients with the Noonan phenotype is important because it will aid in genetic counseling and in the assessment of the natural history of--and, ultimately, identification of the gene(s) responsible for--Noonan syndrome.

Assessment of the orifice diameter by a multigated pulsed Doppler system in children with congenital semilunar valve stenosis.

This study investigated whether the jet diameter measured by a multigated pulsed Doppler system could be used to assess the severity of valve disease in children with pulmonary (n = 11) or aortic (n = 4) valve stenosis. The results obtained were compared with those obtained at cineangiography and at operation. Multigated pulsed Doppler examination of a stenosed valve showed a region of relatively high velocities in the velocity profile (jet flow). There was good agreement between the diameter of the disturbed region on the Doppler echocardiogram and the diameter of the jet on the lateral angiocardiogram. In severe valve stenosis the agreement between the valve diameters measured by multigated pulsed Doppler and at operation was also good. In less severe valve stenosis Doppler measurements systematically underestimated the valve diameter at operation. It is likely that the functional opening of a semilunar valve is a more relevant estimate of the degree of stenosis than the anatomical measurement of the orifice. The findings of this study indicate that multigated pulsed Doppler systems are useful in the noninvasive diagnosis of stenotic valve disease.