Pediatric great vessel anomalies: initial clinical experience with spiral CT angiography.

PURPOSE: To evaluate the use of spiral computed tomographic (CT) angiography for the diagnosis of pediatric great vessel anomalies. MATERIALS AND METHODS: Techniques used in adult CT angiography were modified to allow imaging of 15 children aged 1 month to 12 years. Two-dimensional axial images and three-dimensional shaded surface display images of the airway and great vessels were generated from volumetric CT data and evaluated prospectively. Findings were correlated with results obtained at surgery (five patients), autopsy (one patient), bronchoscopy (one patient), or other imaging studies (eight patients). RESULTS: In 14 patients, CT angiography accurately demonstrated vessel anomalies, including double or right aortic arch (seven cases), aberrant subclavian artery (six cases), innominate artery compression syndrome (one case), unilateral pulmonary artery agenesis (one case), and pulmonary artery enlargement (three cases). One patient had normal vasculature. CONCLUSION: CT angiography is feasible in children and can be used to delineate abnormal great vessel anatomy.

Incidence of aneurysm formation after Dacron patch aortoplasty repair for coarctation of the aorta: long-term results and assessment utilizing magnetic resonance angiography with three-dimensional surface rendering.

OBJECTIVES: Magnetic resonance angiography with three-dimensional surface rendering was performed to determine its value in assessing anatomic detail in patients with suspected aortic aneurysms. BACKGROUND: Dacron patch aortoplasty repair of coarctation of the aorta carries an inherent risk of aneurysm development. Sudden death from aortic rupture prompted discontinuing this operation and evaluating 39 patients (16 girls; mean age 6.3 years, range 10 days to 14.5 years) undergoing repair between January 1976 and October 1987. The aorta ruptured in 10 patients; 6 died at a mean interval of 8.1 years (range 0.75 to 12.4) after repair. All 33 survivors were interviewed and examined. METHODS: Conventional magnetic resonance imaging was performed in 26 patients, magnetic resonance angiography in 18. Angiographic slices were used to reconstruct three-dimensional images. No catheterization or contrast angiography was performed. Surgical intervention was based on clinical findings and magnetic resonance images. RESULTS: Twenty patients (11 girls) developed aneurysms, of which nine were detected in patients studied by magnetic resonance. Ruptures occurred in eight female patients, three of whom were pregnant. Surface renderings accurately defined aortic anatomy or aneurysms in all patients. On follow-up, no aneurysms have been detected in patients with negative magnetic resonance study results. Precise anatomic correlation with operative findings was reported. CONCLUSIONS: Magnetic resonance angiography with three-dimensional surface rendering provides noninvasive, radiation-free and contrast agent-free high resolution images of the thoracic aorta. These images can be reviewed and have three-dimensional form and perspective. These techniques were preferred over invasive angiography by surgeons and clinicians as definitive, risk-free procedures before surgical intervention.

MR imaging of the pediatric airway.

The mainstays of initial evaluation of the airway in infants and children are chest radiography and esophagography. Magnetic resonance (MR) imaging is frequently used next to diagnose specific abnormalities and obviates angiocardiography. MR imaging usually allows distinction between a double aortic arch and a right aortic arch with an aberrant left subclavian artery. In cases of pulmonary artery sling, MR imaging enables full evaluation of the vascular anatomy and may also demonstrate the tracheobronchial anomalies. MR imaging may aid in diagnosis of innominate artery compression syndrome by demonstrating the extent of the tracheal luminal narrowing, the tracheal configuration, the structure causing the compression, and the size of the thymus. Finally, MR imaging usually allows distinction of long-segment tracheal stenosis from tracheomalacia and is especially helpful in cases of isolated stenosis. Three-dimensional reconstructions are also useful in assessing relationships between vascular structures and the adjacent trachea.

Three-dimensional magnetic resonance imaging evaluation of pediatric tracheobronchial tree.

Magnetic resonance imaging (MRI) of the airway has recently emerged as a diagnostic tool for evaluating tracheobronchial obstruction in pediatric patients. Computer-assisted reconstructions of transaxial images have enabled three-dimensional reconstructions of the airway to be manipulated in any plane and visualized in relation to adjacent anatomical structures. Eight patients in whom magnetic resonance imaging was used to diagnose a variety of airway obstructive lesions are presented. A protocol for the evaluation of pediatric tracheobronchial obstruction is presented, with the role of three dimensionally reconstructed MR imaging emphasized.

Magnetic resonance of congenital cardiovascular disease. An update.

Magnetic resonance (MR) has become an important tool in the evaluation of the child who has congenital heart disease. Current techniques and applications of MR in the evaluation of great vessels, vascular causes of airway obstruction, and the postoperative patient are discussed.

Aortic aneurysm after patch aortoplasty repair of coarctation: a prospective analysis of prevalence, screening tests and risks.

Twenty-nine children were evaluated prospectively for the presence of an aortic aneurysm at the repair site 1 to 19 years after patch aortoplasty repair of coarctation of the aorta. In each child, noninvasive evaluation included a chest X-ray film, computed tomography of the chest and two-dimensional echocardiography. The presence and size of an aortic aneurysm were determined quantitatively by measuring the ratio of the diameter of the thoracic aorta at the repair site to the diameter of the aorta at the diaphragm (aortic ratio). An aortic ratio of greater than or equal to 1.5 was judged abnormal and was shown to be significantly greater than the aortic ratio of a normal control group. An aortogram was obtained in each child if any noninvasive screening test was found to be abnormal. As assessed by the aortogram, the prevalence of aortic aneurysm was 24% in this patient group. The sensitivity of echocardiography and chest computed tomography for detecting an aneurysm was 71% and 66%, and the specificity 76% and 85%, respectively. The chest X-ray film was 100% sensitive and 68% specific in determining the presence of an aneurysm. Although the data are not statistically significant, they suggest that children undergoing patch aortoplasty as the primary procedure (rather than a reoperation after earlier resection), and children in whom a Dacron patch is utilized may be at increased risk for aneurysm formation.(ABSTRACT TRUNCATED AT 250 WORDS)

CT and MR of congenital heart disease.

CT and MR join echocardiography in the noninvasive evaluation of the child with congenital heart disease. This article discusses the uses of these modalities in the assessment of the cardiovascular system in children.

Gastrointestinal hemangiomatosis in children: demonstration with CT.

The presence of gastrointestinal (GI) tract hemangiomatosis was demonstrated by computed tomography in two children who presented with lower GI tract bleeding. Marked vascular enhancement of the bowel during rapid intravenous administration of contrast material and dynamic scanning is characteristic, similar to that seen with hemangiomas elsewhere in the body. Barium examinations demonstrate submucosal lesions within the bowel and are useful to approximate the length of bowel involvement.

Physiologic assessment of the four commonly performed endorectal pullthroughs.

The popularity of the endorectal pullthrough for the treatment of benign mucosal diseases of the rectum has created a controversy regarding the need for a reservoir. The four currently advocated procedures, the straight endorectal anastomosis, the J pouch, the S pouch, and the lateral isoperistaltic ileal reservoir were evaluated in a puppy model with four animals in each experimental group. Measurement of rectal capacitance showed that all groups achieved 80-85% of control values at 6 months after surgery. Intestinal transit time decreased by one-half in all groups. Stool consistency, stool culture, water, and electrolyte absorption did not show any statistical superiority of one group over another. Stool frequency varied widely at 6 months; 10 stools per 8-hour period were counted in the lateral reservoir group versus 25 with the J pouches, and 16 with the straight and S groups. Stool frequency did not correlate with transit time, stool consistency, or rectal capacitance. Barium enemas showed that straight pullthroughs more closely resembled the measurements of the normal animal's endorectal canal. Based on these studies, there appears to be no advantage to adding a reservoir to the endorectal pullthrough.

Comparative evaluation of the pulmonary arteries in patients with right ventricular outflow tract obstructive lesions.

The purpose of this prospective study was to assess and compare the roles of CT, sonography, and cineangiography in the evaluation of the central pulmonary arteries. Twenty patients with severe cyanotic congenital heart disease were evaluated. In six patients, cineangiography failed to identify pulmonary arteries (four right, two left) that were seen by CT. Narrowing within the right pulmonary artery was seen more clearly by CT and sonography than by cineangiography in one-third of patients. By contrast, narrowing of the origin of the left pulmonary artery shown by cineangiography was not detected by either CT or sonography in four of four patients. CT has a complementary role and should be performed when the pulmonary arteries are not well seen by cineangiography or sonography, confirmation of the patency and adequacy of the pulmonary arteries is necessary before complete repair, or documentation of interval growth of the pulmonary arteries is desired after palliative surgery.

Coarctation of the aorta in children undergoing angioplasty: pretreatment and posttreatment MR imaging.

Twelve children (aged 4-15 years) with suspected coarctation of the aorta or restenosis of the aorta after previous coarctation repair were considered for balloon angioplasty. Gated magnetic resonance (MR) imaging and cineangiography of the aorta were performed before angioplasty in all 12 children. In six of the nine children treated with angioplasty, MR imaging was performed between 1 day and 4 months later. Correlation with cineangiography showed that MR imaging accurately delineated the site and characteristics of the coarctation before balloon angioplasty. After balloon dilation, MR demonstrated a significant increase in the diameter of the aorta at the coarctation site in four patients and no change in two patients. No complications such as aneurysm formation, dissection, or hematoma were detected as a result of balloon angioplasty in the follow-up MR studies. A decrease in the number and size of collateral vessels was identified in successfully treated patients. MR was useful in identifying patients who were unlikely to benefit from angioplasty, determining the appropriate balloon size for angioplasty, and noninvasively monitoring patients who underwent angioplasty.

The radiographic appearance of the endorectal pull-through.

Children and young adults with ulcerative colitis and polyposis syndromes requiring colectomy are increasingly undergoing the endorectal pull-through procedure. We reviewed the contrast studies of the neorectum of 27 patients and the abdominal radiographs in 26 patients after the endorectal pull-through operation. Normal features included smooth mucosa with loss of the small bowel features, dilatation of the neo-rectum on consecutive examinations, and an enlarged presacral space. The normal appearance before closure of the ileostomy varied depending upon the amount of distension of the pull-through segment; redundant ileum within the rectal muscle sleeve was seen in the two patients. Abnormalities included rectovaginal fistulas, sinus tracts, focal strictures requiring dilatation, complete obstruction, mucosal irregularities, and generalized narrowing with lack of distensibility. These abnormalities are attributable to inflammation and were associated with a poor clinical outcome. A contrast examination of the pull-through segment is useful to exclude the presence of serious inflammatory change before ileostomy closure or in the patient with excessive diarrhea or obstruction.