Preoperative delineation of pulmonary fissural anatomy at multi-detector computed tomography in children with congenital pulmonary malformations and impact on surgical complications and postoperative course.

BACKGROUND: Delineation of the anatomy and integrity of the pulmonary fissures at CT is important because anomalous or incomplete fissures might increase the risk of surgery and of postoperative complications. OBJECTIVE: To preoperatively evaluate the integrity of the pleural fissures in children with congenital lung malformations and determine whether anomalous fissural anatomy is a risk factor for a more complicated surgery and postoperative course. MATERIALS AND METHODS: We reviewed preoperative multi-detector CT scans of consecutive children who underwent open or thoracoscopic resection of a congenital pulmonary malformation from 2008 to 2018, to determine the integrity of the fissural anatomy, and compared these findings with the surgical report. We correlated postoperative factors including operating room time, days in hospital and chest tube with the operating room documented fissural integrity. RESULTS: We saw a significant association between the radiologically determined fissural integrity at CT and the operative findings independently for the right, left and both lungs combined (P<0.001). The sensitivity of CT to determine fissural integrity was 76.9%, specificity 95.2%, positive predictive value 95.2%, negative predictive value 76.9%, and accuracy 85.1%. There was a statistically significant association between size of the pulmonary malformation and the integrity of the fissure(s) (P=0.024). Larger lesions also resulted in a significantly longer hospitalization (P=0.024). CONCLUSION: Chest CT showed high accuracy for delineating fissural anatomy in children with congenital pulmonary malformations, with a good interobserver correlation. Incomplete lung fissures were found more often in children with larger congenital pulmonary malformations. In addition, larger lesions were associated with longer hospital stays. Therefore, children with incomplete fissures may have a longer postoperative course. Analysis of the fissural anatomy should be included in the CT report.

Utility of MDCT MIP Postprocessing Reconstruction Images in Children With Hereditary Hemorrhagic Telangiectasia.

OBJECTIVE: The aim of the study was to evaluate whether maximum intensity projection (MIP) images improve the detection and the delineation of the anatomic makeup of pulmonary nodules and/or arteriovenous malformations (pAVMs) in children with hereditary hemorrhagic telangiectasia (HHT). MATERIALS AND METHODS: Two radiologists (D.M., E.I.C.) performed a blinded review of chest multidetector computed tomography scans in 39 children (age, 0-18 years) with proven HHT. Multiplanar 2.5 mm slices were blindly compared with multiplanar MIP for the presence of nodules and/or overt pAVMs and for the ability to identify vessels associated with the pAVMs. Parameters that were assessed included number of definitive nodules, number of definitive pAVMs, and the ability to detect the feeding artery or draining vein in both conventional and MIP images. RESULTS: Our study showed similar detection rates between axial scans and MIP images for the detection of nodules (axial R1: 75 vs 62, P = 0.05; MIPS: 78 vs 86, P = 0.05) and in the determination of definite pAVMS (axials: 21 vs 29, P = 0.0007; MIPS: 27 vs 35, P = 0.01). Statistically significant differences were obtained in the ability to identify the feeding artery and draining vein between standard 2.5 mm slices and MIP images (axials: 13 vs 13, P = 0.0008; MIPS: 27 vs 23, P = 0.01). No other data parameters achieved statistically significance. CONCLUSIONS: Maximum intensity projection images in children with HHT can help identify the presence and the anatomy of pAVMs for future embolization.

Magnetic resonance imaging of the mediastinum, chest wall and pleura in children.

The acceptance of applications for the use of chest MRI in children has been somewhat slow and selective. The use of MRI to image chest wall lesions is likely the most common and widely used indication, aside from the widespread and somewhat sophisticated use of MRI in imaging the cardiovascular structures of the chest. In this respect, fairly standard variations of T1-W, T2-W and contrast-enhanced imaging can be used, similar to the sequences used for musculoskeletal lesions elsewhere in the body. Imaging of the anterior mediastinal masses should be performed in conjunction with a detailed pre-test clinical examination to determine potential cardiovascular compromise. MRI in the setting of middle mediastinal adenopathy, congenital mediastinal cysts or posterior mediastinal masses, however, has been shown to be more effective and more comprehensive than multidetector CT. Although sonographic imaging is the initial modality of choice for pleural abnormalities, MR imaging is extremely effective and clinically useful in the setting of a potentially ambiguous sonographic examination. Faster imaging protocols are likely to increase the acceptance of MRI to replace multidetector CT for many pediatric chest lesions.

Pulmonary arterial hypertension in children: diagnosis using ratio of main pulmonary artery to ascending aorta diameter as determined by multi-detector computed tomography.

BACKGROUND: The ratio of the transverse diameter of the main pulmonary artery (MPA) to ascending aorta as determined at multi-detector CT is a tool that can be used to assess the pulmonary arterial size in cases of pulmonary arterial hypertension in children. OBJECTIVE: To establish a ratio of MPA to ascending aorta diameter using multi-detector CT imaging suggestive of pulmonary arterial hypertension in children. We hypothesize that a defined ratio of MPA to ascending aorta is identifiable on multi-detector CT and that higher ratios can be used to reliably diagnose the presence of pulmonary arterial hypertension in children. MATERIALS AND METHODS: We calculated the multi-detector CT ratio of MPA to ascending aorta diameter in 44 children with documented pulmonary arterial hypertension by right heart catheterization and in 44 age- and gender-matched control children with no predisposing factors for pulmonary arterial hypertension. We compared this multi-detector-CT-determined ratio with the MPA pressure in the study group, as well as with the ratio of MPA to ascending aorta in the control group. A threshold ratio value was calculated to accurately identify children with pulmonary arterial hypertension. RESULTS: Children with documented primary pulmonary arterial hypertension have a significantly higher ratio of MPA to ascending aorta (1.46) than children without pulmonary arterial hypertension (1.11). A ratio of 1.3 carries a positive likelihood of 34 and a positive predictive value of 97% for the diagnosis of pulmonary arterial hypertension. CONCLUSION: The pulmonary arteries were larger in children with pulmonary arterial hypertension than in a control group of normal children. A CT-measured ratio of MPA to ascending aorta of 1.3 should raise the suspicion of pulmonary arterial hypertension in children.

MR imaging of the chest in children.

The application of magnetic resonance imaging (MRI) to diseases of the pediatric chest has been complicated, selective and cautious. More specifically, MRI of the pediatric lung has been a highly anticipated technique that has inherent great potential for improved imaging of the chest without the use of ionizing radiation. Practical issues impede the transition from multidetector computed tomography (MDCT) to MRI in some chest diseases in children, while other disease states are intrinsically easier to image using MRI. More rapid respiratory and cardiac rates, patient instability, sedation requirements, and the low physical density of water in the lung, hinder the requirement for maximal spatial and contrast resolution. This review is intended to serve as a functional review of the practical and currently applicable ways in which the transition of imaging the non-cardiac aspects of the pediatric chest from MDCT to MRI can be done in a clinically useful way.

Subpleural pulmonary cysts in children: Associations beyond Trisomy 21.

BACKGROUND: Small air-filled peripheral subpleural cysts are a well-described feature of pulmonary anatomy at computerized tomographic (CT) scan in children with Trisomy 21, yet only anecdotally described in association with other pathologies. The significance of these cysts is unknown. OBJECTIVE: To investigate and explore the pathogenesis of these subpleural cysts in children. MATERIALS AND METHODS: A retrospective review of 16 cases with subpleural cysts diagnosed on CT chest was performed. The distribution, location, and ancillary CT findings were recorded. Hospital charts were reviewed for clinical details, especially cardiac abnormalities, pulmonary artery hypertension (PAH) and genetic associations. Histopathological and clinical correlative data were recorded. RESULTS: Eleven of the 16 children (69%) were found to have an underlying chromosomal or genetic abnormality, six of whom had Trisomy 21. The remaining 5 of the 16 cases (21%) had miscellaneous disorders without an identifiable genetic basis. The most common co-morbidities were cardiac abnormalities (81%) and PAH (62.5%). Regardless of their underlying etiologies, the cysts were present bilaterally in most cases (14/16, 88%). We observed both the postnatal development and the progression of cysts in our cohort. On long-term follow-up, there were five deaths (31%) and six cases (38%) requiring maintenance oxygen therapy due to chronic hypoxia. Two cases (12.5%) became completely asymptomatic after correction of their underlying abnormalities. CONCLUSION: Subpleural cysts are not exclusive to Trisomy 21 and may be seen in other inherited or acquired causes, likely due to altered alveolar growth. We suspect these cysts are a sign of an underlying developmental disorder with variable clinical effect, especially in children with congenital cardiac disease.

Pulmonary embolism in children.

Pulmonary embolism (PE) has long been described in children. Nevertheless, most of the algorithms applied to patients within this age range, from diagnosis to therapy, have been adapted from adult protocols. This article reviews the progresses that occurred to PE in children placing them in historical perspective with the key events relevant to PE in adults. A brief summary of the initial reports encountered in the pediatric literature followed by key conclusions drawn from national database reports characterizing its epidemiology in children is highlighted. Additionally, a section with the diagnostic tools pertaining to children is included. Closing remarks encompass commentaries related to therapy and outcomes, reflecting on current knowledge gaps related to PE in children.

A homozygous mutation in the stem II domain of RNU4ATAC causes typical Roifman syndrome.

Roifman syndrome (OMIM# 616651) is a complex syndrome encompassing skeletal dysplasia, immunodeficiency, retinal dystrophy and developmental delay, and is caused by compound heterozygous mutations involving the Stem II region and one of the other domains of the RNU4ATAC gene. This small nuclear RNA gene is essential for minor intron splicing. The Canadian Centre for Primary Immunodeficiency Registry and Repository were used to derive patient information as well as tissues. Utilising RNA sequencing methodologies, we analysed samples from patients with Roifman syndrome and assessed intron retention. We demonstrate that a homozygous mutation in Stem II is sufficient to cause the full spectrum of features associated with typical Roifman syndrome. Further, we demonstrate the same pattern of aberration in minor intron retention as found in cases with compound heterozygous mutations.

Primary sclerosing cholangitis in children: utility of magnetic resonance cholangiopancreatography.

BACKGROUND: Even when histologic findings are highly suggestive of primary sclerosing cholangitis (PSC), cholangiographic correlation is required for the diagnosis. The present gold standard, endoscopic retrograde cholangiopancreatography (ERCP), is invasive and associated with complications. OBJECTIVE: To evaluate the usefulness of magnetic resonance cholangiopancreatography (MRCP) in diagnosing PSC in children. MATERIALS AND METHODS: MRCP studies were retrospectively reviewed in 20 children with clinical suspicion of PSC and who had undergone liver biopsy. MRCP studies were considered positive or negative for PSC depending on the presence or absence of dilatation, irregularity, multifocal strictures and beading of the bile ducts. RESULTS: Twenty children (14 boys, 6 girls) with an average age of 13 years qualified for the study. Of 19 diagnostic MRCP studies, 16 were called positive and 3 were called negative. An overall diagnosis of PSC-positive was assigned to all 19 patients based on clinical and laboratory findings, biopsy results and cholangiographic data. Based on this overall diagnosis, MRCP was 84% sensitive and accurate to diagnose PSC in children. CONCLUSION: MRCP can be a valuable tool in diagnosing pediatric PSC that can demonstrate major intra- and extrahepatic ducts in most cases. An unequivocally positive MRCP study should not be followed by ERCP for diagnosing PSC in children.

Tracheoesophageal fistula without esophageal atresia: are pull-back tube esophagograms needed for diagnosis?

BACKGROUND: A pull-back tube esophagogram (PBTE) is widely accepted in the literature as the radiological investigation of choice for the diagnosis of tracheoesophageal fistula without esophageal atresia. However, PBTE is rarely performed in our institution, as we have been successful in confirming the presence of such fistulae with a contrast material swallow (CS). We hypothesized that PBTE is not the radiological investigation of choice for the diagnosis of the fistula in this condition. OBJECTIVE: We sought to determine what proportion of patients with tracheoesophageal fistula without esophageal atresia can be diagnosed promptly by a CS and what the indications are for a PBTE. MATERIALS AND METHODS: We retrospectively analyzed the clinical and radiological findings in patients with tracheoesophageal fistula without esophageal atresia to determine whether the fistula was diagnosed with a CS or PBTE. RESULTS: We identified 20 children (13 female and 7 male) with tracheoesophageal fistula without esophageal atresia. Their age at diagnosis ranged from 3 days to 168 months with a median of 9 days. The diagnosis was documented by CS in 12, PBTE in 7 and CT in 1. In three of the seven who had the fistula documented by PBTE, a previous CS had shown contrast material in the trachea, but no fistulous tract or aspiration was identified. CONCLUSION: We believe that CS should be the examination of choice in most patients suspected of having a tracheoesophageal fistula without esophageal atresia. A PBTE is indicated in patients who are intubated or are at significant risk of aspiration. Furthermore, a PBTE is also indicated where contrast material is seen in the airway on CS and there is uncertainty whether this is due to aspiration or a fistula.

The role of conservative management in congenital tracheal stenosis: an evidence-based long-term follow-up study.

BACKGROUND/PURPOSE: Surgery has been the management of choice for severe congenital tracheal stenosis (CTS). The role of conservative management of CTS however is not clear. The aim of this study is to characterize the natural history of CTS, review the radiologic evidence of tracheal growth, and evaluate the clinical outcome and selection criteria of conservative management of CTS. METHODS: A retrospective study was carried out on 22 consecutive children with symptomatic CTS admitted into a single institution between 1982 and 2001. The patients were categorized into operation (n = 11) and observation (n = 11) groups. Six patients of the observation group were followed up with serial computed tomography scan. Their tracheal growth was compared with that of healthy children of the same age. RESULTS: The mortality rates of observation and operation groups were 9% and 27%, respectively, although the latter group consisted of more severely affected patients. The pathologic categorization of the CTS influenced the survival rates (P = .046, chi2), with the long segment type having the worst prognosis (67%). Serial computed tomography scans of 6 conservatively managed patients revealed that all stenotic tracheas continued to grow (P = .039, 2-tailed paired Student's t test). Of the 6 stenotic tracheas, 5 grew at a faster-than-normal rate, and the stenotic tracheal diameters approached those of normal diameters by the age of 9 years. CONCLUSIONS: The management of patients with symptomatic CTS should be individualized. A selected group of patients with CTS can be safely managed nonoperatively.

Ileocolic intussusception mimicking the imaging appearance of midgut volvulus as a result of extrinsic duodenal obstruction.

Duodenal obstruction caused by ileocolic intussusception in the absence of intestinal malrotation is extremely rare. We present and discuss the imaging findings in an infant with an intussusception secondary to a duplication cyst in whom sonography also showed inversion of the orientation of the mesenteric vessels and a distended stomach. A contrast medium study revealed a proximal duodenal obstruction with a beak appearance suggestive of midgut volvulus. At surgery, an ileocolic intussusception causing duodenal obstruction without concomitant malrotation or volvulus was found. The combination of duodenal obstruction and abnormal relationship of the mesenteric vessels as a result of ileocolic intussusception has not previously been reported in the literature.

Imatinib mesylate: an attractive alternative in young children with large, surgically challenging dermatofibrosarcoma protuberans.

To document the clinical activity of imatinib mesyalte in a child with a dermatofibrosarcoma protuberans (DFSP). An 18-month-old girl presented with a large extremity DFSP. As surgical resection would have caused unacceptable functional defects, imatinib mesylate was administered to induce tumor reduction and or stabilization. After 23 weeks of therapy, magnetic resonance imaging (MRI) of the tumor showed a reduction in the subcutaneous thickness in the transverse plane. The drug was tolerated well without any adverse reactions. Imatinib mesylate offers a non-surgical alternative for the treatment of large DFSP in children.

Necrotizing enterocolitis: assessment of bowel viability with color doppler US.

PURPOSE: To determine whether absence of bowel wall perfusion at color Doppler ultrasonography (US) is indicative of bowel necrosis in neonates with necrotizing enterocolitis (NEC). MATERIALS AND METHODS: This study was approved by the research ethics board, and informed consent was obtained. Sixty-two neonates enrolled in the prospective study underwent US of the bowel wall. Neonates were divided into two groups. Group A included 30 control subjects with gestational ages (GAs) ranging from 24 to 41 weeks. Group B included 32 neonates with GAs ranging from 24 to 40 weeks who were clinically proved to have or suspected of having NEC. All neonates in group B underwent abdominal radiography. Normative values were calculated in group A. In group B, the sensitivities and specificities of color Doppler US and abdominal radiography for detection of bowel necrosis were computed by using the modified Bell staging criteria for NEC as the reference standard. RESULTS: Two neonates were excluded from group B; thus, a total of 60 neonates were included in the study. In group A, bowel wall thickness ranged from 1.1 to 2.6 mm. Bowel wall perfusion was detected with color Doppler US in all 30 neonates. Color Doppler signals ranged from one to nine dots per square centimeter. Twenty-two of 30 neonates in group B received a diagnosis of NEC. Mild to moderate NEC was diagnosed in 12 neonates. Color Doppler US depicted an isolated segment of bowel-absent blood flow in two neonates; this finding was confirmed with laparotomy. In 10 neonates with severe NEC, color Doppler US depicted isolated or multiple segments of bowel with absent perfusion. Pneumoperitoneum was present in only four neonates. The remaining eight neonates at risk for NEC had no evidence of loops without perfusion at color Doppler US. The sensitivity of free air at abdominal radiography as a positive sign for severe NEC with necrotic bowel was 40% compared with the 100% sensitivity of absence of flow at color Doppler US (P = .03). CONCLUSION: Color Doppler US is more accurate than abdominal radiography in depicting bowel necrosis in NEC.

Hepatic and colonic perforation by an abandoned ventriculoperitoneal shunt.

We report a case of an abandoned distal limb of a ventriculoperitoneal shunt that resulted in hepatic as well as colonic perforation in a 12-year-old girl. Although it is common practice at the time of shunt revision to leave a retained distal catheter in the peritoneal cavity, we suggest this can result in perforation of solid as well as hollow viscera.