Complex congenital heart malformation evaluated with MR imaging at 0.3 T.

The aim of this study was to evaluate the efficiency of MR imaging at 0.3 T as the single modality in diagnosing complex congenital heart disease (CHD). Films from 45 cases were reviewed in two stages by four specialists and one fellow in pediatric radiology, who were unfamiliar with the patients. First a general review of CHD diagnosis was made, then a detailed study of anomalous venous return was performed. Regarding the general diagnosis of cardiovascular anomalies the results were good, with sensitivity of 80%, specificity of 96%, a positive predictive value of 88%, a negative predictive value of 93% and accuracy of 92%. As expected, the less experienced reviewer had somewhat lower figures. As for detailed evaluation of the anomalous veins, the diagnostic results were again good (sensitivity 85%), although less so when also the connection sites of the anomalous veins were considered (sensitivity 79%). The specificity of the findings was high at 97%. MR imaging at 0.3 T is valuable in the diagnosis of complex CHD, especially for anomalous vessels and their connections.

A postoperative follow-up study of infantile coarctation of the aorta.

Follow-up investigations were performed in 16 patients operated on for coarctation during infancy. The follow-up period ranged from 4.5 to 11 years (median 5.5 years). Four different surgical techniques were used: resection with end-to-end anastomosis (REE) (4 patients), subclavian flap aortoplasty (SFA) (10 patients), patch aortoplasty (1 patient) and resection and SFA (1 patient). One patient developed recoarctation (6%). She had been operated on by REE at 7 days of age. The other three patients operated on by REE had equal pulses in the arms and legs; none had hypertension and all had normal arm/leg pressure gradients at rest. Seven (58%) of the 12 patients operated on by SFA or aortoplasty had weak radial pulses in the left arm but no limitation of left arm function. The left a rm showed a normal bone age but was smaller and shorter than the right arm in 9 (81%) of the patients. None of the patients operated on by SFA had hypertension and the arm/leg gradient at rest was normal.

Postoperative pulmonary vascular supply in congenital heart disease evaluated with MR imaging at 0.3 T.

The aim of this study was to investigate the usefulness of static spin-echo MR imaging at low field strength in evaluating postoperative pulmonary arterial supply. Twenty-seven patients operated on for complex congenital heart disease underwent cardiac MR imaging: 27 stenoses in 20 patients and 4 aneurysms were present in the material. Five of the overlooked stenoses were located in the ventricular outflow tract or in the valvular region. All four aneurysms were well depicted. The final diagnosis were based on two-dimensional echocardiography, Doppler and invasive studies. MR correctly evaluated the pulmonary arterial supply in 21 patients. In two cases the evaluation was incomplete and in the remaining four patients MR failed to show the stenoses. MR imaging at 0.3 T is an effective non-invasive tool for postoperative evaluation of pulmonary arteries.

Percutaneous translumbar central venous catheter in infants and small children.

Vascular occlusion is a common clinical problem in children dependent on prolonged vascular access. As an alternative to conventional central venous catheter placement we report our experience of four children receiving translumbar inferior vena cava catheter on 12 different occasions. All catheter placements were successful. No procedure-related complications occurred. The median catheter patency was 4.8 months (range 1-10 months). The translumbar route for central venous access is safe and reliable and should be considered when prolonged use is anticipated in infants and small children.

Pulmonary complications of umbilical venous catheters.

Umbilical venous catheters that are pushed in too far will usually cross the atrial septum and may dislodge in a pulmonary vein. The authors report eight neonates with radiographic documentation of this catheter malposition together with either a localized pulmonary opacification or an autopsy report of a pulmonary hemorrhage or infarction corresponding to the catheter position. The lung injury ranged from a transient edema to hemorrhagic pulmonary infarction and hydrothorax. In two cases autopsy demonstrated localized infarction without previous radiographic signs of catheter-related injury.

Vertical field MR imaging of upper thorax and spine in small children. Evaluation of a new surface coil.

To improve image quality in a vertical field MR imaging unit, operating at low field strength (0.3 T), we have designed a half-elliptical coil for use in the upper thoracic region of small children. Our intention was also to shorten the examination time, which until now has been long, because several scans with different coils have been necessary to cover the thoracic region. The experimental coil is designed so that a child's shoulders fit into the central region. The coil consists of 2 serially connected cable-loops, mounted on a foam rubber vest. The coil performance was tested in a phantom and improvements relative to standard coils were demonstrated in in vivo studies. The results indicate that by using the half-elliptical coil, the signal-to-noise (S/N) ratio can be improved by a factor of 2 to 3 in the thoracic region of a child.

Optimizing conventional cardiac MRI in the rabbit at 0.3 T.

The aim of this study was to define the most efficient way of performing cardiac MRI for anatomic information in small experimental animals, using a vertical magnetic field with a strength of 0.3 T (FONAR beta-3000M). This information may be used to improve cardiac MRI in infants and small children, since the size of a rabbit is considered comparable to that of a neonate. Experimental axial cardiac MRI studies were performed in a rabbit under general anesthesia in order to study the effects on image quality of changing various imaging parameters. These are ECG-gating, number of excitations (averages), number of warp levels, echo time (TE) and repetition time (TR). The effects of changing the size of the field of view (FOV), the slice thickness and the phase-encoding direction were also studied. We found that ECG-gating was crucial and that three excitations, TE 16 ms, and 257 vertical phase-encoding warp levels were adequate. Five-millimeter slice thickness and FOV 20 cm were preferred.

Computed tomography and magnetic resonance tomography findings in children operated for anal atresia.

Computerised tomography and magnetic resonance tomography were performed in nine faecally incontinent patients more than eight years after rectoplasty for high imperforate anus. No statistically significant correlation was found between function, i.e. degree of faecal incontinence, and anatomical findings. Thus, in spite of a detailed demonstration of the post-operative anatomy, the information does not seem to be directly applicable in indicating a way to reoperate for faecal incontinence in this group of patients.

Spontaneous pneumopericardium in an otherwise healthy full-term newborn.

Neonatal pneumopericardium is usually a complication of mechanical ventilation in premature infants with respiratory distress syndrome. We report a full-term neonate who developed pneumopericardium after forceps delivery and mild asphyxia. The child was never ventilated and had no signs of parenchymal lung disease. The pneumopericardium resolved spontaneously. Although drainage of pneumopericardium is usually recommended, this may not always be necessary when there are no signs of cardiac tamponade.

Hemarthrosis after femoral neck fracture fixation.

In 34 femoral neck fractures, CT was performed within 1-32 days after internal fixation. All the cases except one showed an increased distance between the femoral neck and the anterior aspect of the joint capsule as compared with the intact side, indicating varying degrees of hip joint effusion and/or synovitis. Hip joint aspiration in 11 patients revealed increased intracapsular pressure varying between 10 and 112 mmHg and volumes of aspirated joint effusion up to 23 ml. Pain relief and increased joint motion after drainage of the intracapsular effusion was observed in 3 patients whose postoperative mobilization was facilitated.

Pulmonary artery sling. Diagnosis by magnetic resonance imaging.

Aberrant left-sided pulmonary artery (pulmonary sling) is an uncommon anomaly, which may cause significant respiratory morbidity. The condition should be considered on finding a mass interposed between the trachea and the esophagus on the esophagogram, but diagnosis is usually made with invasive methods. Magnetic resonance imaging (MRI) has been reported as an excellent method for diagnosing cardiovascular anomalies but the findings at MRI in cases of pulmonary artery sling have not been reported previously. In this communication the use of MRI is described for demonstration of pulmonary sling in three patients.

Mediastinal pseudomass: pneumonia and atelectasis behind the left pulmonary ligament.

In children, left lower lobe pneumonia posterior to the pulmonary ligament may mimic a paramediastinal mass. Over a period of 6 years we have seen 12 children with this unusual appearance, which we attribute to a peculiar type of atelectasis or infiltration of the left lower lobe or a segment of it. The radiographic appearance is thought to be the result of incomplete anchoring of the left lung by a short pulmonary ligament. The radiographic findings are demonstrated, and the benign clinical course is emphasized.

Management of neonatal hip instability: an analysis of the efficiency in a consistent treatment program.

The efficiency of a consistent treatment program for children with neonatal hip instability (NHI) was analyzed. Of 165 children who were referred to the orthopedic department with suspected NHI, 91 children had unstable hips and were treated with a von Rosen splint for 8 weeks; 74 children were found to have stable hips and were not treated, but were followed up in the same way as the treated children. All treated and untreated children developed clinically and radiologically normal hips. Treatment with a von Rosen splint is reliable, and with few exceptions 8 weeks is sufficient time for treatment of NHI.