Fabio Triulzi

Demonstration of acute ischemic lesions in the fetal brain by diffusion magnetic resonance imaging

The possibility of detecting acute hypoxic‐ischemic brain lesions by prenatal magnetic resonance imaging or ultrasound is low. We present a case of a fetus with a vein of Galen arteriovenous malformation in whom prenatal diffusion‐weighted magnetic resonance imaging at 33 weeks of gestation clearly detected cerebral acute ischemic lesions, associated with remarkable decrease of the average apparent diffusion coefficient, whereas T2‐weighted imaging was still not informative.

Early Cerebral Lesions in Cytomegalovirus Infection: Prenatal MR Imaging

PURPOSE To assess the diagnostic and prognostic value of fetal cerebral magnetic resonance (MR) imaging of congenital cytomegalovirus (CMV) infection in comparison with that of level II ultrasonography (US). MATERIALS AND METHODS Institutional review board approval and informed consent for fetal MR imaging and data collection were obtained. Thirty-eight fetuses with CMV infection, examined by using serial level II US, underwent fetal MR imaging (mean gestational age, 25 weeks; age range at first fetal MR examination, 20-34 weeks). The frequency of pathologic findings at US (29 cases with transabdominal examination and nine cases with both transabdominal and transvaginal examination) and MR imaging was calculated, and a comparison between techniques by considering number (paired Student t test) and type (McNemar test) of finding was made. A comparison (paired Student t test) in cases of repeated fetal (nine of 38) and/or postnatal (14 of 38) MR imaging was obtained. Diagnostic and prognostic sensitivity was calculated for both techniques. RESULTS US and MR imaging findings were both normal in 47% of cases (18 of 38). Abnormal studies were reported in 26% (10 of 38) of US and 53% (20 of 38) of MR imaging cases. In 47% of cases (18 of 38), MR imaging provided additional information (P = .0002). MR imaging had better results than US in detecting polar temporal lesions (P = .0001), microencephaly (P = .03), and cortical anomalies (P = .06). In 44.5% of cases (four of nine), the second fetal MR examination results showed new findings (P = .05). In 79% of cases, postnatal MR imaging results confirmed prenatal findings (P = .08). MR imaging had higher sensitivity than US in detecting brain anomalies (92% vs 38%) and in predicting symptomatic infection (83% vs 33%). US and MR imaging revealed low positive predictive values (29% vs 36%). CONCLUSION Fetal MR imaging results can show abnormalities in the fetal brain after CMV infection, even when US results are normal. The early detection of some brain abnormalities, such as microencephaly and cortical anomalies, may substantially influence the prognosis of fetal infection.

Paraclinical tests in acute-onset optic neuritis : basal data and results of a short follow-up

ABSTRACT Up to now it is still doubtful whether there is a real risk of developing multiple sclerosis (MS) after initial monosymptomatic optic neuritis (ON). In this study we evaluated 43 patients with isolated acute‐onset ON, in order to demonstrate the presence of oligoclonal bands (OBs) in the cerebrospinal fluid (CSF) and any additional clinically silent central nervous system (CNS) lesions. All examinations were performed from 5 days to 4 months (mean 43 days), from the onset of visual disturbances. Brain magnetic resonance imaging (MRI) detected white matter areas with increased signal in 21 patients (49%), while somatosensory and brainstem auditory evoked potentials revealed CNS abnormalities in only 5 patients (12%). OBs were present in the CSF of 20 patients (46%). Visual evoked potentials were abnormal in 39 patients (91%). Seven out of the 37 patients (19%) with at least one year follow‐up, (mean duration of the follow‐up = 32 months, range=12‐74), developed clinically definite MS (CDMS). All 7 patients had positive brain MRI and 6 had positive CSF examination at the basal evaluation. Our data suggest that MRI and CSF‐OBs are the most reliable means of identifying patients with isolated ON who subsequently develop CDMS. They may therefore have a predictive value in defining MS risk.

Magnetic resonance imaging assessment of brain maturation in preterm neonates with punctate white matter lesions

IntroductionEarly white matter (WM) injury affects brain maturation in preterm infants as revealed by diffusion tensor imaging and volumetric magnetic resonance (MR) imaging at term postmenstrual age (PMA). The aim of the study was to assess quantitatively brain maturation in preterm infants with and without milder forms of WM damage (punctate WM lesions, PWML) using conventional MRI.MethodsBrain development was quantitatively assessed using a previously validated scoring system (total maturation score, TMS) which utilizes four parameters (progressive myelination and cortical infolding, progressive involution of glial cell migration bands and germinal matrix tissue). PWML were defined as foci of increased signal on T1-weighted images and decreased signal on T2-weighted images with no evidence of cystic degeneration. A group of 22 preterm infants with PWML at term PMA (PWML group) were compared with 22 matched controls with a normal MR appearance.ResultsThe two groups were comparable concerning gestational age, birth weight and PMA. TMS was significantly lower in the PWML group than in the control group (mean TMS 12.44 ± 2.31 vs 14.00 ± 1.44; P = 0.011). Myelination (mean 2.76 ± 0.42 PWML group vs 3.32 ± 0.55 control group, P = 0.003) and cortical folding (3.64 ± 0.79 vs 4.09 ± 0.43, P = 0.027) appeared to be significantly delayed in babies with PWML.ConclusionConventional MRI appears able to quantify morphological changes in brain maturation of preterm babies with PWML; delayed myelination and reduced cortical infolding seem to be the most significant aspects.

Bilateral perisylvian polymicrogyria in three generations.

Article abstract A family is described in which bilateral perisylvian polymicrogyria was present in 6 members of 3 consecutive generations. Typical anatomic and clinical findings of the syndrome, with a mild phenotype, were present in the 5 affected women from all 3 generations. More severe impairment was observed in the only affected male individual, a boy, in the third generation. Analysis of the pedigree and severity of the phenotype in the affected boy are consistent with transmission of an X-linked dominant trait, although other patterns of inheritance cannot be ruled out with certainty.

Acute subarachnoid Haemorrhage: 3D time-of-flight MR angiography versus intra-arterial digital angiography

To evaluate the efficacy and reliability of 3D time-of-flight MR angiography (TOF MRA) as a noninvasive procedure, 27 patients with acute subarachnoid haemorrhage (SAH) were studied with MRA immediately before or after intra-arterial digital subtraction angiography (DSA). 3DTOF MRA was performed with an axial slab of 60 mm centred on the circle of Willis and isotropic voxels. DSA showed 22 aneurysms and 1 dural arteriovenous fistula in 21 patients; the aneurysms ranged in size from 2 to 8 mm. MRA failed to show 2 small aneurysms, at the origin of the posterior and anterior communicating arteries. The 3D display of the intracranial vessels obtained with maximum intensity projection (MIP) or targetted MIP sometimes rendered the aneurysms better than DSA. However, due to its high spatial resolution, DSA more clearly defined the overall anatomy of the walls of the normal and abnormal vessels.

Hypopituitarism and Stalk Agenesis: A Congenital Syndrome Worsened by Breech Delivery?

Thirty-seven patients with idiopathic hypopituitarism, of whom 12 had multiple pituitary hormone deficiencies (MPHD) and 25 isolated growth hormone deficiency (IGHD), were evaluated by magnetic resonance imaging (MRI). Twenty-two of the 37 showed congenital anterior pituitary hypoplasia, stalk agenesis and ectopic posterior pituitary gland at the infundibular recess (group A), while the remaining 15 presented isolated anterior pituitary hypoplasia (group B). Perinatal histories obtained from all patients demonstrated that 18/22 children of group A (81.81%) had histories of adverse perinatal events, with breech presentation in 15 (68.18%). Twelve of 12 children of group A born by breech delivery developed MPHD; 3 born by cesarean section for breech presentation had only IGHD. Patients of group B had also a high incidence of perinatal insults (12/15, 80%), but breech delivery was markedly less frequent (13.33 vs. 68.18% of group A) and responsible for only IGHD. Group B had also higher percentages of maternal spontaneous abortion and low birth weight. Our study suggests that several factors may play a role in the development of growth hormone deficiency. Some patients had severe perinatal insults apparently leading to hypopituitarism. We were able to define by MRI a group of patients with congenital abnormalities, such as anterior pituitary hypoplasia, stalk agenesis and posterior pituitary ectopia, among whom breech presentation was very common. In this group, breech delivery was always followed by MPHD while cesarean or normal delivery in such patients was followed by IGHD only.

Proton magnetic resonance spectroscopy and intracranial tumours: Clinical perspectives

Proton magnetic resonance spectroscopy (1H-MRS) was applied to characterize intracranial tumours of different hystological types. Seventy patients with intracranial neoplasms were studied before receiving surgery, radiotherapy or chemotherapy. All tumours were characterized by reduced or absentN-acetylaspartate and increased signal from choline-containing compounds. Distinctive patterns were observed only for primitive brain neoplasms; high-grade gliomas were differentiated from low-grade ones by higher levels of choline-containing compounds. The metabolic aspects of metastatic lesions were similar to high-grade gliomas. These results, together with the limitations of1HMRS and future applications are reviewed.

Hypothalamic-pituitary dwarfism: Comparison between MR imaging and CT findings

Magnetic Resonance (MR) imaging was carried out on 33 patients with idiopathic growth hormone deficiency, in 22 of whom CT scan had been carried-out previously. Twenty-one patients presented some complications at birth. Both MR and CT were positive in the evaluation of the sella. MR imaging exhibited a higher degree of accuracy than CT in the evaluation of pituitary gland, pituitary stalk and brain anomalies.On the basis of pituitary morphology demonstrated by MR imaging, and perinatal histories, a classification is proposed which divides our patients into three group: A) a first group of 13 patients presenting severe hypoplasia of the anterior pituitary lobe, hypoplasia of the stalk and ectopia of posterior lobe. The underlying cause of these anatomic defects might be developmental in origin, and date from early intrauterine life, probably worsened at birth. B) a second group of 10 patients presenting severe hypoplasia of the anterior pituitary lobe. A perinatal event and birth trauma might be responsible for pituitary damage. C) a third group of 10 patients with no morphological abnormalities of the pituitary gland. A derangement of the neuroendocrine mechanism which control the growth hormone secretion might account for these patients.

Diffusion-weighted magnetic resonance imaging of acute hypoxic-ischemic cerebral lesions in the survivor of a monochorionic twin pregnancy : case report

Monochorionic twin pregnancies complicated by the death of one twin are associated with substantial morbidity in the survivor, with a high risk of developing hypoxic‐ischemic brain damage. In this report, we demonstrate how prenatal diffusion‐weighted magnetic resonance imaging detected focal ischemic lesions in the survivor of a monochorionic twin pregnancy within 1–2 days of cotwin death. A very early diagnosis of cerebral ischemic lesions might influence the management of the pregnancy. Copyright