[Congenital malformations of the lung, the radiologist's point of view]

Congenital lung malformations include a complex range of developmental abnormalities. Currently, most are diagnosed prenatally or during early childhood. They may, however, be discovered later, incidentally or in connection with non-specific symptoms, sometimes severe. Knowledge of their radiological appearances is necessary for their detection. Proper technique and analysis of cross-sectional imaging, computed tomography and magnetic resonance imaging, allow a definitive diagnosis in most patients and pre-treatment evaluation of surgical cases. This review will describe the radiological aspects of congenital pulmonary malformations, especially those which may occur in late childhood or adult life. When present, alternative diagnoses will be discussed. A distinction will be made between anomalies originating from bronchopulmonary structures, such as bronchial atresia, bronchogenic cyst, congenital lobar overinflation, cystic adenomatoid malformation, and forms related to vascular anomalies (vascular rings, anomalous left pulmonary artery, pulmonary underdevelopment, proximal interruption of the pulmonary artery, pulmonary sequestration, scimitar syndrome).

Primary aneurysmal bone cysts in children: percutaneous sclerotherapy with absolute alcohol and proposal of a vascular classification

BACKGROUND

Percutaneous sclerotherapy is an effective treatment for aneurysmal bone cysts (ABCs).

OBJECTIVE

The purpose of this study was to demonstrate the safety and efficacy of sclerotherapy with absolute alcohol and to propose a vascular classification of ABCs based on a retrospective review.

MATERIALS AND METHODS

This was a review of children treated with absolute alcohol sclerotherapy for ABC at a single institution from January 1995 until November 2009. Treatment response was evaluated radiographically and clinically. Cyst fluid was classified as clear, partially bloody, or bloody. Presence of any venous drainage of the cyst was assessed by injection of contrast medium into the cyst cavity.

RESULTS

Twenty-nine children with ages ranging from 2 to 16 years were included. Treatment response was good in 17 (59%), partial in 9 (31%), and poor in 3 (10%) children. Venous drainage was absent in six out of seven clear-fluid cysts, which we classified as lymphatic. Drainage was present in all seven bloody-fluid cysts, which we classified as venous. In seven partially bloody-fluid cysts, venous drainage was seen in three.

CONCLUSION

Sclerotherapy with absolute alcohol is a safe and effective treatment of ABC. We propose classifying ABC as lymphatic or venous and suggest considering ABC intraosseous slow-flow vascular malformations.

A common pattern of brain MRI imaging in mitochondrial diseases with complex I deficiency

OBJECTIVE

To identify a consistent pattern of brain MRI imaging in primary complex I deficiency. Complex I deficiency, a major cause of respiratory chain dysfunction, accounts for various clinical presentations, including Leigh syndrome. Human complex I comprises seven core subunits encoded by mitochondrial DNA (mtDNA) and 38 core subunits encoded by nuclear DNA (nDNA). Moreover, its assembly requires six known and many unknown assembly factors. To date, no correlation between genotypes and brain MRI phenotypes has been found in complex I deficiencies.

DESIGN AND SUBJECTS

The brain MRIs of 30 patients carrying known mutation(s) in genes involved in complex I were retrospectively collected and compared with the brain MRIs of 11 patients carrying known mutations in genes involved in the pyruvate dehydrogenase (PDH) complex as well as 10 patients with MT-TL1 mutations.

RESULTS

All complex I deficient patients showed bilateral brainstem lesions (30/30) and 77% (23/30) showed anomalies of the putamen. Supratentorial stroke-like lesions were only observed in complex I deficient patients carrying mtDNA mutations (8/19) and necrotising leucoencephalopathy in patients with nDNA mutations (4/5). Conversely, the isolated stroke-like images observed in patients with MT-TL1 mutations, or the corpus callosum malformations observed in PDH deficient patients, were never observed in complex I deficient patients.

CONCLUSION

A common pattern of brain MRI imaging was identified with abnormal signal intensities in brainstem and subtentorial nuclei with lactate peak as a clue of complex I deficiency. Combining clinico-biochemical data with brain imaging may therefore help orient genetic studies in complex I deficiency.

Surfactant protein C gene (SFTPC) mutation-associated lung disease: high-resolution computed tomography (HRCT) findings and its relation to histological analysis

AIM OF THE STUDY

Determine high-resolution tomography (HRCT) scan characteristics in children with SFTPC mutation and correlate them to histological findings.

PATIENTS AND METHODS

This retrospective multicenter study included 15 children (7 females and 8 males) with SFTPC mutations. HRCT scans have been performed in all the children and lung biopsies in 8 children.

RESULTS

From all signs assessed on initial HRCT scans, ground-glass opacities (n =14, 93%) and lung cysts (n = 6, 40%) were predominant. Interlobular septal thickening (n = 1, 7%), air space consolidation (n = 1, 7%), paraseptal emphysema (n = 2, 13%), and pulmonary nodules (n = 1, 7%) were also found. Histological analysis revealed accumulation of macrophages in the alveolar lumen, type II pneumocyte hyperplasia, and alveolar septal thickening. Dilatation of the respiratory bronchiole and alveolar duct associated with muscular hyperplasia were also described. Interestingly, lung cysts on HRCT scans were associated with dilatation of terminal bronchioli and alveolar duct in lung biopsies.

CONCLUSION

In children with SFTPC mutations, HRCT scan finding was highly correlated to the histological findings and, as such, represent a useful tool to identify patients that may require SFTPC gene sequencing.

Phacomatosis pigmentokeratotica with nephroblastoma and juvenile hypertension

Phacomatosis pigmentokeratotica is characterized by the coexistence of an organoid epidermal naevus, follow-ing Blaschko's lines, and a large speckled lentiginous naevus, typically arranged in a chequerboard pattern. This entity has been isolated from the group of epidermal naevus syndromes and is frequently associated with extracutaneous anomalies. We report here the first observation of phacomatosis pigmentokeratotica associated with nephroblastoma. In addition to this paediatric renal tumour, the coexistence of juvenile arterial hypertension suggests an associated vascular defect. The link between the extracutaneous manifestations and cutaneous twin spot phenotype is discussed.

Posterior fossa imaging in 158 children with ataxia

OBJECTIFS

To propose a MRI cerebellar algorithm that may be applied to guide genetic/malformative or biochemical investigations for patients with cerebellar ataxia.

PATIENTS AND METHODS

Cerebral MRI of 158 patients with cerebellar ataxia and no supratentorial abnormality were examined according to a new categorization system based on posterior fossa imaging. The clinical and radiological findings were confronted to biochemical and/or genetic results using the MR cerebellar algorithm. Seven groups of cerebellar MRI pattern were described: vermian dysgenesis (n=27), cerebellar hypoplasia (n=15), hemispheric cerebellar dysgenesis (n=6), unilateral hemispheric atrophy (n=5), global cerebellar atrophy (n=84), signal abnormalities (n=11) and normal MRI (n=10). Cerebellar hypoplasia, vermian dysgenesis and hemispheric cerebellar dysgenesis groups were classified as malformative disorders. Global atrophy and signal abnormality groups were classified as metabolic disorders.

RESULTS

In the vermian dysgenesis group, a specific genetic diagnosis was obtained in eight children (8/27) and all of the mutated genes (AHI1 (JBS3), CEP290 (JBS5), TMEM67 (JBS6), and RPGRIP1L (JBS7)) are involved in primary cilia function. In the group of pontocerebellar hypoplasia specific genetic diagnosis was obtained in one patient (PCH2) (1/15). Thus, nine of 42 children classified as malformative disorder had a molecular diagnosis. Global atrophy and signal abnormality groups were classified as metabolic disorders, specific biochemical was obtained in 46/95 children. In global atrophy group, respiratory chain deficiency was diagnosed in 18 children (18/84). In 21 children a congenital disorders of glycosylation type 1a (CDG Ia) was diagnosed (21/84) and infantile neuroaxonale dystrophy (INAD) was diagnosed in one child. In signal abnormalities group, specific biochemical diagnosis was obtained in six out of 11 children, five children with respiratory chain deficiency and one child with sulphite oxidase deficiency. In hemispheric cerebellar dysgenesis and normal MRI groups, no biological diagnosis was found for any of the patients. In the group of unilateral hemispheric atrophy, we hypothesized a clastic prenatal injury.

CONCLUSION

The proposed MR cerebellar algorithm was useful to guide genetic/malformative or biochemical investigations, allowing an etiological diagnosis in 55 children.

Mutations in the mitochondrial glutamate carrier SLC25A22 in neonatal epileptic encephalopathy with suppression bursts

Neonatal epileptic encephalopathies with suppression bursts (SBs) are very severe and relatively rare diseases characterized by neonatal onset of seizures, interictal electroencephalogram (EEG) with SB pattern and very poor neurological outcome or death. Their etiology remains elusive but they are occasionally caused by metabolic diseases or malformations. Studying an Arab Muslim Israeli consanguineous family, with four affected children presenting a severe neonatal epileptic encephalopathy, we have previously identified a mutation in the SLC25A22 gene encoding a mitochondrial glutamate transporter. In this report, we describe a novel SLC25A22 mutation in an unrelated patient born from first cousin Algerian parents and presenting severe epileptic encephalopathy characterized by an EEG with SB, hypotonia, microcephaly and abnormal electroretinogram. We showed that this patient carried a homozygous p.G236W SLC25A22 mutation which alters a highly conserved amino acid and completely abolishes the glutamate carrier's activity in vitro. Comparison of the clinical features of patients from both families suggests that SLC25A22 mutations are responsible for a novel clinically recognizable epileptic encephalopathy with SB.

Real-time fetal magnetic resonance imaging for the dynamic visualization of the pouch in esophageal atresia

Esophageal atresia is the principal cause of congenital esophageal obstruction. Prenatal suspicion of esophageal atresia is usually based on the presence of polyhydramnios together with an absent stomach bubble. More recently, visualization of the dilatation of the blind-ending esophagus (esophageal pouch) during fetal swallowing has been reported and proposed as the most reliable sign for predicting esophageal atresia. Improvement of radiofrequency and computer technology as well as parallel data acquisition has greatly reduced magnetic resonance (MR) scanning time, allowing visualization of the fetus in cine-mode using fast imaging employing steady-state acquisition (FIESTA). We describe the application of FIESTA sequences in fetuses with suspected esophageal atresia for visualization of the esophageal pouch using MR imaging.

Neonatal ruptured intracranial aneurysms: case report and literature review

INTRODUCTION

Intracranial aneurysms are exceptional in neonatal patients: There are only 16 cases previously reported. We describe the first case of neonatal posterior inferior cerebellar artery (PICA) aneurysm and review the literature.

CASE REPORT

A 7-day-old girl presented with irritability, anorexia, fever and abnormally enlarging head circumference. Computed tomography (CT) and magnetic resonance (MR) imaging demonstrated intraventricular haemorrhage, secondary hydrocephalus and a pontine cistern haematoma. A PICA aneurysm was suspected on the CT angiogram (CTA) and the diagnosis was confirmed by conventional cerebral angiography. She was successfully treated by surgical clipping of the parent vessel and excision of the aneurysm. Postoperatively, she experienced transient swallowing difficulties and required a ventriculo-peritoneal shunt for hydrocephalus. Histopathological evaluation demonstrated a calcified arterial wall with thrombosis, signs of prior haemorrhage and the absence of the internal elastic lamina.

CONCLUSION

Neonatal intracranial aneurysms are rare. Clinical presentation of subarachnoid haemorrhage in this age group is often non-specific. First-line investigation should start with transfontanelle cranial ultrasound, followed by MR angiography then CTA if necessary. Posterior circulation aneurysms and large or giant aneurysms are more frequent in neonates and children than in adults. Early diagnosis and treatment are important for improved outcome. Surgery is better tolerated than in adults.

Risk assessment of acute vascular events in congenital disorder of glycosylation type Ia

The congenital disorder of glycosylation type Ia (CDG-Ia) presents a broad clinical spectrum. Some patients suffer from acute vascular events (thrombosis and bleeding) and stroke-like events. No correlations have been made between the marked hemostasis abnormalities of CDG-Ia and the occurrence of acute vascular events. We report on 6 patients with CDG-Ia presenting vascular events, then we analyze the clinical and hemostasis data of 39 CDG-Ia patients described in the literature, 17 with vascular events (E) and 21 unscathed from any event (EF), to determine the risk factors for acute vascular events in CDG-Ia. Acute vascular events occurred in patients younger than 15 years, especially with fever and prolonged immobilization. Hemostasis and liver cytolysis were statistically abnormal in patients younger than 5 years whatever the occurrence of vascular events and they normalized with time. Higher factors VIII and IX activities were statistically observed in the E cluster (p=0.03) compared to the EF cluster. The activity/antigenicity ratio for protein C (p=0.02) was also higher in the E group. CDG-Ia patients younger than 15 years old are at risk of acute vascular events. The paradoxical results-abnormal VIII and IX factors in EF patients and normal results in E patients, while XI, antithrombin, protein C, ASAT and ALAT are abnormal in both groups, could suggest a disequilibrium between prothrombotic and antithrombotic factors in the E group. Vascular events may also occur in patients where glycoproteins are proportionally more hypoglycosylated, particularly protein C.

1H MRS spectroscopy evidence of cerebellar high lactate in mitochondrial respiratory chain deficiency

Cerebellar ataxia is known to occasionally occur in the course of mitochondrial disorders. We report on MR spectroscopy (1H MRS) evidence of elevated brain lactate in the cerebellar area of 11 patients with cerebellar ataxia ascribed to mitochondrial respiratory chain deficiency (RCD). 1H MRS spectroscopy evidence of lactate peak was found in the cerebellum of 9/11 cases, while no lactate was detected in the putamen in 8/11. We suggest using 1H MRS in cerebellar atrophy in the diagnosis of mitochondrial RCD.