A rare case of mediastinal lymphatic venous malformations in children.

We report a case of mediastinal lymphatic venous malformations (LVM) in a 11-year-old boy who presented with chest pain after jumping into a swimming pool, with review of the literature. A superior mediastinal mass was incidentally found from the chest x-ray. Chest computed tomography revealed a large heterogenous mass at the left-sided mediastinum containing fat, minimal enhancing solid portion, non-enhancing cystic portion and calcification. Because of the large size of the mass, the patient underwent tumour removal. Operative findings gave a definitive diagnosis of mediastinal LVM. The patient had an uneventful clinical course and was discharged without complication. This report highlights that it is possible to misdiagnose mediastinal LVM especially if its predominant portion is lymphatic tissue with only minimal contrast enhancement. Tissue biopsy must be avoided because it may lead to haemorrhagic complication.

Congenital lung lesions: prenatal MRI and postnatal findings.

BACKGROUND: Congenital lung lesions refer to a spectrum of malformations and developmental abnormalities of the foregut, pulmonary airways and vasculature. These lesions range from small, asymptomatic to large space-occupying masses that can increase risk of fetal death and respiratory compromise after birth. Prenatal sonography has been used for routine screening in pregnancy. The advent of prenatal magnetic resonance imaging leads to complementary use in the diagnosis of fetal anomalies, including in fetuses with congenital lung lesions. OBJECTIVE: To determine whether fetal MRI can differentiate congenital lung lesions by comparing prenatal diagnosis with postnatal imaging and pathology. MATERIALS AND METHODS: In a 4-year period, 76 fetuses with suspected lung lesions were referred for fetal MRI. We retrospectively reviewed the MR exams and assigned a specific diagnosis based on predetermined criteria. We then compared the prenatal diagnosis to postnatal imaging and pathology. RESULTS: Of 76 cases, 7 were excluded because of an alternative diagnosis. Of the 69 remaining patients, 3 died and 13 were lost to follow-up. Among the 53 patients, there were 56 lung lesions. Four of these lesions were difficult to diagnose because of size and location. Based on imaging records we gave the remaining 52 lesions a specific prenatal diagnosis: 28 congenital pulmonary airway malformations (CPAM), 4 bronchopulmonary sequestrations (BPS), 9 cases of overinflation, 9 hybrid lesions and 2 bronchogenic cysts. The prenatal diagnosis was concordant with postnatal evaluation in 51 of the 52 lung lesions. One fetus given the diagnosis of CPAM prenatally was diagnosed with a hybrid lesion postnatally. CONCLUSION: Prenatal MRI is highly accurate in defining congenital lung anomalies. When fetal MRI findings suggest a specific diagnosis, postnatal findings confirmed the prenatal MRI diagnosis in 98% of cases.

Sonography in the evaluation of acute appendicitis: are negative sonographic findings good enough?

OBJECTIVE: The purpose of this study was to evaluate the negative predictive value (NPV) of sonography in the diagnosis of acute appendicitis. METHODS: Right lower quadrant sonograms of 193 patients (158 female and 35 male; age range, 3-20 years) with suspected acute appendicitis over a 1-year period were retrospectively reviewed. Sonographic findings were graded on a 5-point scale, ranging from a normal appendix identified (grade 1) to frankly acute appendicitis (grade 5). Sonographic findings were compared with subsequent computed tomographic (CT), surgical, and pathologic findings. The diagnostic accuracy of sonography was assessed considering surgical findings and clinical follow-up as reference standards. RESULTS: Forty-nine patients (25.4%) had appendicitis on sonography, and 144 (74.6%) had negative sonographic findings. Computed tomographic scans were obtained in 51 patients (26.4%) within 4 days after sonography. These included 39 patients with negative and 12 with positive sonographic findings. Computed tomography changed the sonographic diagnosis in 10 patients: from negative to positive in 3 cases and positive to negative in 7. Forty-three patients (22.2%) underwent surgery. The surgical findings were positive for appendicitis in 37 (86%) of the 43 patients who had surgery. Patients with negative sonographic findings who, to our knowledge, did not have subsequent CT scans or surgery were considered to have negative findings for appendicitis. Seven patients with negative sonographic findings underwent surgery and had appendicitis; therefore, 137 of 144 patients with negative sonographic findings did not have appendicitis. On the basis of these numbers, the NPV was 95.1%. CONCLUSIONS: Sonography has a high NPV and should be considered as a reasonable screening tool in the evaluation of acute appendicitis. Further imaging could be performed if clinical signs and symptoms worsen.

Imaging findings in pediatric patients with persistent airway symptoms after surgery for double aortic arch.

OBJECTIVE: The purpose of this study was to review the imaging findings of children referred for cross-sectional imaging to evaluate persistent airway symptoms after surgical therapy for double aortic arch. CONCLUSION: Airway narrowing is clearly shown on cross-sectional imaging in patients with persistent airway symptoms after surgical therapy for double aortic arch. Two patterns of airway compression are typically seen: narrowing of the trachea at the level of the postsurgical arch and narrowing of the left main bronchus as a result of compression from a midline descending aorta. Both patterns may be seen in patients regardless of whether the left or the right arch has been ligated.

Aberrant subclavian arteries: cross-sectional imaging findings in infants and children referred for evaluation of extrinsic airway compression.

OBJECTIVE: The purpose of our study was to describe patterns of airway compression identified on cross-sectional imaging in infants and children with either right aortic arch and aberrant left subclavian artery or left aortic arch with aberrant right subclavian artery. MATERIALS AND METHODS: Data from MR imaging and CT performed to evaluate pediatric patients for extrinsic airway compression were reviewed for cases that revealed an aberrant right or left subclavian artery. Clinical, endoscopic, and imaging findings in identified cases were reviewed. Recurrent patterns of extrinsic compression were reviewed among cases. RESULTS: Twelve patients with right aortic arch with aberrant left subclavian artery and nine patients with left aortic arch and aberrant right subclavian artery were identified. All 12 with right aortic arch with aberrant left subclavian artery had airway compression shown, with multiple sites or diffuse compression in six. Of these 12 patients, nine had compression at the level of the arch and aberrant subclavian artery (10 had Kommerell's diverticulum), and nine had compression of the distal airway in association with a midline descending aorta. Five of the nine patients with left aortic arch and aberrant right subclavian artery had airway compression shown, all at the level of the arch and aberrant subclavian artery. None of these compressions was associated with either Kommerell's diverticulum or midline descending aorta. CONCLUSION: Both right and left aberrant subclavian arteries can be associated with symptomatic airway compression, but the patterns of compression are different. The airway compression in right aortic arch with aberrant left subclavian artery is often associated with either Kommerell's diverticulum or midline descending aorta, whereas compression associated with left aortic arch and aberrant right subclavian artery is not.

Are chest radiographs routinely necessary following thoracostomy tube removal?

OBJECTIVE: Chest radiographs (CXRs) are routinely obtained at many institutions in all pediatric patients following thoracostomy tube removal to search for pneumothorax (PTX). To aid in evaluating the necessity of this practice, this study investigates whether clinical signs and symptoms may be a sensitive predictor of PTX in such patients. MATERIALS AND METHODS: Reports from CXRs obtained following chest tube removal in all pediatric patients (374 patients) who underwent cardiac surgery with chest tube placement over 1 year were reviewed. For cases with reported PTX, the PTX was quantified and chart review was performed to assess whether signs and symptoms of PTX preceded the CXR result. RESULTS: Fifty-one of 374 children (13.6%) had a radiographically defined PTX within 6 h after thoracostomy tube removal. The PTX was large (>40%) in 2 children, moderate (20-40%) in 5 children, and small (<20%) in 44 children. Symptoms (dyspnea, tachypnea, respiratory distress) or signs (increased oxygen requirement, worsening arterial blood gas and/or hypotension) of respiratory distress were present at the time of the initial CXR in six of seven patients, who later underwent a major clinical intervention, and in one patient who did not. Major clinical interventions were performed in all patients with a large PTX, four of five patients with a moderate PTX, and one patient with a small PTX that later enlarged. CONCLUSIONS: Clinical signs and symptoms identified nearly all patients with significant pneumothoraces. Future prospective investigations may examine reserving chest radiography following chest tube removal for select groups, such as symptomatic patients or those with tenuous cardiovascular status.