Advanced multiparametric magnetic resonance imaging of multinodular and vacuolating neuronal tumor.

BACKGROUND AND PURPOSE: Multinodular and vacuolating neuronal tumor (MVNT) of the cerebrum is a rare brain lesion with suggestive imaging features. The aim of our study was to report the largest series of MVNTs so far and to evaluate the utility of advanced multiparametric magnetic resonance (MR) techniques. METHODS: This multicenter retrospective study was approved by our institutional research ethics board. From July 2014 to May 2019, two radiologists read in consensus the MR examinations of patients presenting with a lesion suggestive of an MVNT. They analyzed the lesions' MR characteristics on structural images and advanced multiparametric MR imaging. RESULTS: A total of 64 patients (29 women and 35 men, mean age 44.2 ± 15.1 years) from 25 centers were included. Lesions were all hyperintense on fluid-attenuated inversion recovery and T2-weighted imaging without post-contrast enhancement. The median relative apparent diffusion coefficient on diffusion-weighted imaging was 1.13 [interquartile range (IQR), 0.2]. Perfusion-weighted imaging showed no increase in perfusion, with a relative cerebral blood volume of 1.02 (IQR, 0.05) and a relative cerebral blood flow of 1.01 (IQR, 0.08). MR spectroscopy showed no abnormal peaks. Median follow-up was 2 (IQR, 1.2) years, without any changes in size. CONCLUSIONS: A comprehensive characterization protocol including advanced multiparametric magnetic resonance imaging sequences showed no imaging patterns suggestive of malignancy in MVNTs. It might be useful to better characterize MVNTs.

Multinodular and Vacuolating Posterior Fossa Lesions of Unknown Significance.

Multinodular and vacuolating neuronal tumor of the cerebrum is a rare supratentorial brain tumor described for the first time in 2013. Here, we report 11 cases of infratentorial lesions showing similar striking imaging features consisting of a cluster of low T1-weighted imaging and high T2-FLAIR signal intensity nodules, which we referred to as multinodular and vacuolating posterior fossa lesions of unknown significance. No relationship was found between the location of the lesion and clinical symptoms. A T2-FLAIR hypointense central dot sign was present in images of 9/11 (82%) patients. Cortical involvement was present in 2/11 (18%) of patients. Only 1 nodule of 1 multinodular and vacuolating posterior fossa lesion of unknown significance showed enhancement on postcontrast T1WI. DWI, SWI, MRS, and PWI showed no malignant pattern. Lesions did not change in size or signal during a median follow-up of 3 years, suggesting that multinodular and vacuolating posterior fossa lesions of unknown significance are benign malformative lesions that do not require surgical intervention or removal.

Expanding the clinical and neuroradiologic phenotype of primary microcephaly due to ASPM mutations.

OBJECTIVE: To determine the spectrum of clinical, neuropsychological, and neuroradiologic features in patients with autosomal recessive primary microcephaly (MCPH) due to ASPM gene mutations. METHODS: ASPM was sequenced in 52 unrelated MCPH probands. In patients with ASPM mutations, we evaluated the clinical phenotype, cognition, behavior, brain MRI, and family. RESULTS: We found homozygous or compound heterozygous ASPM loss-of-function mutations in 11 (22%) probands and 5 siblings. The probands harbored 18 different mutations, of which 16 were new. Microcephaly was severe after 1 year of age in all 16 patients, although in 4 patients the occipital-frontal circumference (OFC) at birth was decreased by only 2 SD. The OFC Z score consistently decreased after birth. Late-onset seizures occurred in 3 patients and significant pyramidal tract involvement in 1 patient. Intellectual quotients ranged from borderline-normal to severe mental retardation. Mild motor delay was noted in 7/16 patients. Language development was delayed in all patients older than 3 years. Brain MRI (n = 12) showed a simplified gyral pattern in 9 patients and several malformations including ventricle enlargement (n = 7), partial corpus callosum agenesis (n = 3), mild cerebellar hypoplasia (n = 1), focal cortical dysplasia (n = 1), and unilateral polymicrogyria (n = 1). Non-neurologic abnormalities consisted of short stature (n = 1), idiopathic premature puberty (n = 1), and renal dysplasia (n = 1). CONCLUSIONS: We provide a detailed description of features associated with ASPM mutations. Borderline microcephaly at birth, borderline-normal intellectual efficiency, and brain malformations can occur in ASPM-related primary hereditary microcephaly.

[Direct foreign body footplate trauma: 3 cases]. / Traumatisme direct de la platine par corps étranger, à propos de 3 cas.

3 cases of direct foreign body footplate trauma are described in children. A surgical exploration was decided on history, cochleovestibular signs and/or CT abnormalities. Hearing improved in all cases after surgery.

Contribution of single-photon emission computed tomography in the diagnosis and follow-up of CNS toxicity of a cytarabine-containing regimen in pediatric leukemia.

PURPOSE: Cytarabine (ara-C) is one of the most effective chemotherapeutic agents in patients with acute leukemia (AL), with a clear dose effect. Use of high-dose ara-C is hampered, however, by a noticeable toxicity, particularly to the CNS. We investigated the usefulness of CNS perfusion imaging with technetium-99m ((99m)Tc)-hexamethyl-propylene-amine oxime (HMPAO) single-photon emission computed tomography (SPECT) concurrent to magnetic resonance imaging (MRI) to specifically assess the effects of standard- and high-dose ara-C in children with AL. PATIENTS AND METHODS: Twenty-six perfusion studies using (99m)Tc-HMPAO SPECT were performed in 12 children (age range, 4 to 15 years) with AL after induction therapy, which consisted of a standard-dose ara-C, immediately after consolidation with high-dose ara-C, and later during follow-up (range, 6 to 44 months). The chemotherapy-related adverse events were monitored and correlated to SPECT and MRI. RESULTS: After the induction phase, all children were neurologically normal on MRI. On SPECT imaging, four children displayed a slightly heterogeneous perfusion. After high-dose ara-C (4 to 36 g/m(2)), five children had regressive neurologic signs of potential toxic origin. Of these five children, only one had an abnormal MRI scan, whereas all patients showed evidence of diffuse cerebral and/or cerebellar heterogeneous perfusion on SPECT. The seven other patients without any neurologic symptoms had normal MRI scans; SPECT was normal for three patients and abnormal for four patients. On follow-up, for four children who had presented with clinical neurologic toxicity, SPECT improved in three patients and remained unchanged in one patients. In two of these four children, delayed abnormalities (T2 white matter hypersignal and cerebellar atrophy) appeared on MRI scans. CONCLUSION: In our series, diffuse heterogeneous brain hypoperfusion is often the sole early objective imaging feature identified by SPECT of high-dose ara-C neurotoxicity, where MRI still demonstrates normal pictures.

Transnasal endoscopic repair of congenital defects of the skull base in children.

OBJECTIVE: To examine imaging findings and methods of endoscopic treatment of congenital skull base defects in children. DESIGN: Retrospective study and case series. SETTING: Academic tertiary care center. PATIENTS: Four patients (aged 12 and 14 months and 8 and 13 years) were included from 1995 to 1997. Three presented with a nasal glioma, which was recurrent in 1 case. The fourth patient presented with bacterial meningitis due to a spontaneous cerebrospinal fluid leak. Computed tomography and magnetic resonance imaging were used to locate the defect of the skull base. INTERVENTION: Transnasal endoscopic resection of the glioma or the meningocele, with immediate repair of the skull base defects using free mucosal flaps and/or pediculized mucosal flaps and/or conchal cartilage together with fibrin glue and nasal packing during a 3-week period. RESULTS: None of the 4 patients has experienced recurrent cerebrospinal fluid leaks or postoperative meningitis. CONCLUSIONS: The transnasal endoscopic repair of congenital meningoceles is a reliable technique in select pediatric patients. Computed tomography and magnetic resonance imaging provide information that can be used to help the surgical procedure.

[Prenatal MRI of corpus callosum agenesis. Study of 20 cases with neuropathological correlations]. / IRM anténatale des agénésies calleuses. Etude de 20 cas avec corrélations neuropathologiques.

Twenty prenatal MR studies of corpus callosum agenesis were retrospectively studied and compared with neuropathologic examinations (18) or postnatal imaging (2). Corpus callosum agenesis were either complete (14) or partial (6). Positive diagnosis was made in 19 cases/20. The diagnosis of "isolated" or "associated" corpus callosum agenesis was assessed in 11 cases/15. MR depicted 15 of the 33 associated neurologic abnormalities. Prenatal MR is a valuable complementary technique for the diagnosis of corpus callosum agenesis when sonography is doubtful. MR could improve prognosis evaluation, since it enables depiction of associated abnormalities, notably gyral abnormalities, posterior fossa malformations, and intra-cranial cysts. MR images prove to be useful before neuropathologic examinations.

Unusual presentation of a first branchial cleft.

An atypical case of a first branchial cleft presenting with a cutaneous fistula and an epidermoid cyst of the external auditory canal is reported. The relevant embryology of the branchial apparatus is summarized, and variations of first branchial anomalies are discussed. The relationship with a congenital cholesteatoma is discussed.

Ultrasonographic evaluation of the tongue and the floor of the mouth: normal and pathological findings.

An ultrasonographic study of the tongue and the floor of the mouth was performed in 30 healthy children (aged from 1 day to 15 years) in order to assess the normal US anatomy of this region. The scans were performed in sagittal and coronal planes with a 7.5-mHz transducer. Moreover, 22 children (aged from 1 day to 15 years) presenting with various clinical symptoms underwent US examination. This series included infectious and congenital diseases. The US findings were correlated with surgery and pathology in 19 cases, with the clinical follow-up in 2 cases and with the nuclear study in 1 case. In each case, US could anatomically locate the lesion with very good accuracy. We conclude that US of the tongue and the floor of the mouth in children yields overall very good accuracy in the investigation of diseases of this region. In this study, our purpose was (1) to evaluate the normal sonographic anatomy of the tongue and the floor of the mouth in children and (2) to determine whether it was possible to correctly localize various lesions and to evaluate their nature in order to guide the therapeutic approach.

[Dysphagia in children. Imaging]. / Dysphagie de l'enfant. Imagerie.

While oesophageal obstacles are responsible for regurgitation or aspiration in neonates and infants, older children present with dysphagia. Before any investigation, a buccopharyngeal infection must first be eliminated clinically. In the absence of fever, the ingestion of a foreign body or caustic substances must be considered, either in an acute context, or in a chronic context related to cicatricial stenosis. Tumour or congenital lesions are less common, whether intrinsic (stenosis, fistulas, duplications), or extrinsic (vascular malformations, mediastinal tumours). Radiological investigation is based on simple techniques: chest X-ray and barium swallow are usually sufficient to establish the aetiological diagnosis.

[Oculo-orbital anatomy and nuclear magnetic resonance: use in ocular growth and fetal pathology]. / Anatomie oculo-orbitaire et résonance magnétique nucléaire: application à la crossiance oculaire et à la pathologie foetale.

The computation of eyeball growth has a wide field of applications in orbital and ocular pathology. An anatomic, macroscopic, histologic and RMI study has correlated the different oculo-orbital signals with the anatomy: a study of compute eyeball growth has been done. The anatomic study was made to determine the best MRI parameters to calculate the ocular surface. The surface was computed by MRI T2 weighted in the neuro-ocular plane in children aged from 0 to 13 years. The curve of eyeball growth shows rapid growth in utero until 18 months and then a phase of slower growth. A second study with fetuses RMI of pregnant women showed the neuro-ocular plane of fetus. Application in antenatal pathology are interesting. Two cases of orbital tumor, with fetal diagnosis are analysed and histologically explained.

[Study of facial neuralgia]. / Exploration d'une névralgie faciale.

So-called idiopathic, essential trigeminal neuralgia is characterised by typical severe pain in the territory of the trigeminal nerve or one of its divisions. This entity remains a diagnosis of exclusion after investigation by computerized tomography and/or magnetic resonance imaging of the path of the trigeminal nerve and its branches, to exclude any neoplastic, inflammatory, infectious or vascular process. Nevertheless, surgical exploration and now medical imaging have revealed in a large number of cases of "idiopathic" essential trigeminal neuralgia, compression of the trigeminal nerve as it emerges from the brainstem by a vascular loop.