M. Bonamini

Correlation between MRI findings and long-term outcome in patients with severe brain trauma

Abstract Our aim was to relate MRI findings in patients with severe traumatic brain injury (TBI) to clinical severity and long-term outcome. We studied 37 patients with severe TBI, who were submitted to clinical assessment for disability and cognition and to MRI 60–90 days after trauma. Clinical assessment was also performed 3, 6 and 12 months later. The number and volume of lesions in various cerebral structures were calculated semiautomatically from FLAIR and fast field-echo images. Possible correlations between total and regional lesion volume and clinical deficits were then investigated. The frontal and temporal lobes were most frequently involved. Total lesion volume on FLAIR images correlated significantly with clinical outcome, whereas that on FFE images did not. Regional analysis showed that FLAIR lesion volume in the corpus callosum correlated significantly with scores on disability and cognition scales at the first clinical assessment. FLAIR lesion volume in the frontal lobes correlated significantly with clinical scores 1 year later.

Magnetic resonance imaging in Posterior Reversible Encephalopathy Syndrome: report of three cases and review of literature

IntroductionEclampsia is one of the main causes of Posterior Reversible Encephalopathy Syndrome (PRES) a recent clinico-neuroradiological entity represented by characteristic MR findings of a symmetric bilateral subcortical/cortical hyperintensity in T2-weighted images, more often in parieto-occipital lobes, accompanied by clinical neurological alterations. Neuroradiological and clinical alterations are commonly completely reversible although ischemic evolution has been described. The pathophysiology is still a matter of debate. Specific magnetic resonance (MR) techniques, such as FLAIR (fluid attenuated inversion recovery) and DWI (diffusion weighted images) sequences, have improved the ability to detect subcortical/cortical lesions and helped to clarify the underlying pathophysiological mechanism of cerebrovascular involvement, which results important for an appropriate therapeutic decision.Case report and discussionWe report the MR imaging findings of three patients with eclampsia and PRES as well as a careful review of literature.

Measurement of Cerebrospinal Fluid Flow: Technique Validation in a Patient with Idiopathic Normal Pressure Hydrocephalus

This study aimed to assess anatomical and functional changes disclosed by magnetic resonance imaging in a patient with suspect normal pressure hydrocephalus following surgical third ventriculostomy with placement of a ventriculoperitoneal shunt. The patient was investigated by phase contrast sequences to calculate CSF flow in the Sylvian aqueduct before and after the two surgical procedures. In addition, T1-weighted volumetric MPRAGE images were acquired using voxel-based morphometry to study any changes in size of the ventricular system and CSF in the subarachnoid spaces before and after surgery. CSF flow measurements were closely correlated with the patients clinical course, increased CSF flow coinciding with worsening symptoms, and a decrease in flow noted after surgery. There were no significant changes in the CSF volumes analyzed. Phase contrast technique proved reliable and effective for the purposes of diagnosis and long-term follow-up in patients with suspect normal pressure hydrocephalus eligible for surgery

Atassia cerebellare di Friedreich: Uno studio di voxel-based morphometry (VBM)

L’atassia di Friedreich (FRDA) è il tipo più comune di atassia ereditaria. La malattia colpisce prevalentemente le vie afferenti propriocettive e cerebellari, ma anche il sistema piramidale. Manifestazioni caratteristiche comprendono atassia del tronco e degli arti, disartria, alterazioni dei movimenti oculari e ariflessia tendinea. I pazienti affetti da tale patologia mostrano i primi sintomi nell’adolescenza e perdono la capacità di deambulazione intorno ai 20 anni; sono inoltre presenti segni di coinvolgimento multisistemico quali la cardiomiopatia ipertrofica e il diabete mellito. Il 99% dei pazienti affetti da FRDA presenta alterazioni del gene della fratassina, caratterizzate da eccessive ripetizioni della tripletta GAA, Gli studi di anatomia patologica hanno messo in evidenza la presenza di una caratteristica atrofia del cervelletto e del midollo spinale. Tale reperto è stato confermato anche da studi morfologici con risonanza magnetica . Il voxel-based morphometry (VBM) 1 è una recente tecnica che permette di visualizzare l’esistenza di zone di atrofia corticale. Pertanto abbiamo applicato tale tecnica per valutare l’eventuale esistenza di aree atrofiche e la loro localizzazione in pazienti affetti da FRDA. L’obiettivo del presente lavoro è stato quello di visualizzare con un metodo altamente sensibile le modificazioni morfologiche che avvengono in pazienti affetti da FRDA e che potrebbero essere difficili da quantificare con uno studio morfologico. Materiale e metodi

Ruolo della Neuroradiologia nella diagnostica della malformazione di Chiari di I tipo

Chiaris type I malformation is defined as the caudal displacement of the cerebellar tonsils into the occipital foramen, sometimes associated with displacement of the cerebellar vermis. Syringomyelia is present in 65% of patients with Chiaris type I malformation and in 25% of all cases of tonsillar ectopia detected by MR scan. In contrast, asymptomatic syringomyelia is sporadic. MR investigation of the whole spinal cord is indicated when Chiaris type I malformation is present. Although the incidence of symptomatic patients increases when the ectopia exceeds 5 mm, there are no statistically significant correlations between the size of cerebellar ectopia and the incidence of syringomyelia or the degree of other clinical manifestations such as headache, Ménières syndrome and inferior cranial nerve impairment. Symptoms and hence prognosis and possible surgical treatment depend not only on the tonsillar displacement, but on its impact on CSF dynamics. Cine-MR scanning offers great potential in the assessment of CSF dynamics in the occipital foramen, revealing asymptomatic subjects at risk of developing syringomyelia. The surgical treatment of this category of patients remains a controversial topic.

Utilità delle sequenze turbo-flair e analisi volumetrica della regione ippocampale nella valutazione del paziente con epilessia temporale farmaco-resistente:

The aim of this study was to evaluate the hippocampal region using Fluid Attenuation Inversion Recovery sequences (Turbo-FLAIR) to detect signal intensity abnormalities, and volumetric sequences to detect cortical thickness changes, in patients with drug-resistant temporal epilepsy. We evaluated 30 patients with drug-resistant temporal epilepsy with a 1.5 Tesla unit (NT 15 Philips Gyroscan). Conventional SE, Turbo SE, IR, Turbo-FLAIR, volumetric 3D sequences on coronal plane, PD, T2weighted SE sequences on axial plane, T1-weighted SE on sagittal plane / were performed. Signal intensity and volumetric computerized measurements were obtained using the SUN system. Differences in signal intensity values between the two hippocampal regions were found in 18 patients with Turbo-FLAIR sequences. In 6 of the sepatients no significant differences in computerized evaluation of signal intensity were detected with either conventional or Turbo-SE sequences. Volumetric analysis showed hippocampal cortex thinning in 9 out of 18 patients with hippocampal signal intensity abnormalities. Turbo -FLAIR provided the best sequences for the detection of signal intensity changes in the hippocampal region. Such changes are strongly suggestive of hippocampal sclerosis, especially when associated with cortical atrophy.