Dynamic magnetic resonance imaging of endoscopic third ventriculostomy patency with differently acquired fast imaging with steady-state precession sequences

The aim of the study was to determine the possibilities of two differently acquired two-dimensional fast imaging with steady-state precession (FISP 2D) magnetic resonance sequences in estimation of the third ventricle floor fenestration patency after endoscopic third ventriculostomy (ETV) in the subjects with aqueductal stenosis/obstruction.Fifty eight subjects (37 males, 21 females, mean age 27 years) with previously successfully performed ETV underwent brain MRI on 1.5T MR imager 3-6 months after the procedure. Two different FISP 2D sequences (one included in the standard vendor provided software package, and the other, experimentally developed by our team) were performed respectively at two fixed slice positions: midsagittal and perpendicular to the ETV fenestration, and displayed in a closed-loop cinematographic format in order to estimate the patency. The ventricular volume reduction has been observed as well.Cerebrospinal fluid (CSF) flow through the ETV fenestration was observed in midsagittal plane with both FISP 2D sequences in 93.11% subjects, while in 6.89% subjects the dynamic CSF flow MRI was inconclusive. In the perpendicular plane CSF flow through the ETV fenestration was visible only by use of experimentally developed FISP 2D (TR30/FA70) sequence. Postoperative volume reduction of lateral and third ventricle was detected in 67.24% subjects.Though both FISP 2D sequences acquired in midsagittal plane may be used to estimate the effects of performed ETV, due to achieved higher CSF pulsatile flow sensitivity, only the use of FISP 2D (TR30/FA70) sequence enables the estimation of the treatment effect in perpendicular plane in the absence of phase-contrast sequences. 

Brain white matter 1 H MRS in Leber optic neuropathy mutation carriers

OBJECTIVE

This study was conducted in order to test the hypothesis that proton MR spectroscopic (1H MRS) profile of Leber's hereditary optic neuropathy (LHON) mutation carriers group (including both symptomatic and asymptomatic) differs from group of healthy individuals and to determine metabolite or ratio that contributes most to differentiation.

PATIENTS AND METHODS

We performed single voxel 1H MRS in normal appearing white matter of eighteen LHON mtDNA mutation carriers bearing one of three LHON mtDNA point mutations and in fifty control subjects.

RESULTS

ANOVA showed significant difference for absolute concentration of creatine (Cr) (p < 0.01) and N-acetylaspartate to creatine ratio (NAA/Cr) (p < 0.01). Discriminant analysis revealed that decreased absolute Cr followed by decreased absolute NAA concentration have the most significant contribution in discriminating LHON mutation carriers from healthy controls.

CONCLUSION

Abnormal metabolic profile in normal appearing white matter on MR imaging seems to be significantly present in LHON mutation carriers.

Prenatal diagnosis of posterior fossa anomalies--an overview

Ultrasonography of the central nervous system is an integral part of a prenatal scan, and the development of imaging technologies has led to better diagnostic possibilities. Posterior fossa anomalies have traditionally been divided into Dandy Walke malformation, Dandy Walker variation and megacisterna magna, but this approach, due to diversity of the extensive number of possible disorders covered by this classification, unables accurate prognosis and therefore adequate counselling. An alternative approach to the classification of posterior fossa anomalies is to divide them into agenesis of the vermis, which could be partial or complete, cerebellar hypoplasia, pontocerebellar hypoplasia and cerebellar atrophy. Different ultrasonographic and magnetic resonance imagining of appearances of the posterior fossa anomalies in prenatal period are discussed in the article, as well as possible syndromes and prognosis of different entities. Diversity of anomalies of the central nervous system, and in particular, subtle differences in prenatal appearances of posterior fossa anomalies, which may have major impact on the prognosis, demand a multidisciplinary approach that encompasses two-dimensional and three-dimensional ultrasound scan, magnetic resonance imaging, infectious diseases and metabolic disorders work-ups as well as individual approach to every case involving of a team of experts in the field of perinatology, radiology, paediatrics, neurology and genetics.

[Prenatal diagnosis of granular cell myoblastoma--a case report]

INTRODUCTION

The aim of this paper is to present a case of prenatal diagnosis of a congenital tumor of the oral cavity diagnosed at 28 weeks of gestation.

CASE REPORT

After the diagnosis of oral cavity tumor was made by 21) ultrasound, a 3D scan was performed, which confirmed the diagnosis revealing a peduncle at the upper border of maxilla. A detailed scan was performed and no additional anomalies were seen. Magnetic resonance imaging was performed, confirming the diagnosis and the site of the tumor. Karyotype was previously done, and a normal female karyotype was found. Regular three-week follow-up scans were performed to follow the growth of the tumor, as well as the state of the amniotic fluid. No tumor growth was detected, and the amniotic fluid volume was normal until 39 weeks of gestation. Cesarean section was scheduled, due to the risk of tumor disruption during a vaginal delivery. A maxillofacial surgeon was present during an uneventful cesarean section and a complete surgical excision was done immediately after the baby was extracted and umbilical cord ligated. The histopathological diagnosis was: granular cell myoblastoma. The female newborn was developing normally, and at 5 months of age there were no traces of scarring at the place of the tumor.

CONCLUSION

In cases of prenatal diagnosis of tumors of the oral cavity, where development of polyhydramnios can be expected, as well as difficulties with feeding and breathing after birth, it is important to make a plan for adequate follow-up and prompt surgical treatment immediately after birth.

[Reversible brain damage following acute poisoning with an organic solvent determined by magnetic resonance]

INTRODUCTION

Acute exposure to the effects of volatile solvents is characterized by the abrupt onset of symptoms and signs of poisoning, and relatively fast recovery in the majority of cases.

CASE REPORT

We report a 24-year-old patient with an acute, accidental poisoning with a mixture of volatile organic solvents (most probably toluene, styrene and xylene), which led to the development of upward gaze paresis, diplopia, hemiparesis, ataxic gate, and the late onset truncal ataxia episodes. After 6 weeks, he recovered completely, while his extensive brain MRI lesions in the caudate nuclei, laterobasal putaminal regions, bilateral anterior insular cortex, central midbrain tegmental area) withdrew completely after 4 months.

CONCLUSION

Acute toxic encephalopathy should be a part of the differential diagnosis in any patient with acute neurobehavioral and neurological deficit.

Emery-Dreiffus muscular dystrophy: MR imaging and spectroscopy in the brain and skeletal muscle

Emery-Dreifuss muscular dystrophy is a rare disorder characterized by childhood onset of contractures, humeroperoneal muscle atrophy, and cardiac conduction abnormalities. This report presents the cases of two brothers with this dystrophy in whom bilateral hypomyelination of the deep periatrial white matter was noted. In the hypomyelinated regions, a prominent peak centered at 1.5 parts per million was present on short-TE MR spectra likely representing prominence of proteolipids in the macromolecular region. Major peaks (N-acetyl-aspartate, creatine, choline, and myoinositol) were normal. With respect to muscle changes, atrophy of the medial head of the gastrocnemius muscle was noted at MR imaging, and phosphorus spectroscopy of this muscle revealed decreased phosphocreatine and inorganic phosphate peaks.

Bilateral chorea-ballism associated with hyperthyroidism

We describe a 50-year-old patient with four episodes of recurrent bilateral chorea-ballism (BCB) and associated hyperthyroidism. Reappearance of BCB, associated with increased serum levels of thyroid hormones and lack of relevant changes on brain computed tomography/magnetic resonance imaging scans, suggested that the involuntary movements were likely due to thyrotoxicosis-induced biochemical changes.