A. F. Marliani

3T MRI in the Evaluation of Brain Aneurysms Treated with Flow-Diverting Stents: Preliminary Experience

Deployment of stents across the neck of intracranial aneurysms to isolate the lesion from the circulation is a recently introduced endovascular treatment. These devices are known as flow-diverting stents because the stent mesh design drastically slows the blood flow within the aneurysm sac, thereby stimulating thrombus formation. Treated aneurysms require close follow-up monitoring using an effective minimally invasive method. We devised a dedicated follow-up protocol using a high field strength magnetic resonance system (MR) with gadolinium administration to monitor 11 patients treated by insertion of flow-diverting stents. Findings were compared with the results of a reference imaging procedure (CT angiography). MR accurately demonstrated patency of the stent lumen and monitored the evolution of the aneurysmal sac in all patients. Gadolinium administration proved essential in two patients to depict the complete exclusion of the flow within the aneurysmal sac.

CE-MR Angiography at 3.0 T Magnetic Field in the Study of Spinal Dural Arteriovenous Fistula Preliminary Results

SUMMARYnWe report technical data and results in eight patients studied with spinal contrast-enhanced MR angiography (CE-MRA). We used a 3.0 Tesla device, dedicated phased array coil and time resolved imaging of contrast kinetics (TRICKS) sequences to visualize the feeder vessels in patients with vascular malformations. TRICKS is a method of 3D CE-MRA providing temporal information. Thanks to its high temporal and spatial resolution and high signal/noise ratio the TRICKS optimized sequence at 3.0 T yielded very encouraging results in disclosing the origin of arteriovenous malformations.

Role of Contrast-Enhanced Magnetic Resonance Angiography in Spinal Dural Arteriovenous Fistula

Spinal dural arteriovenous fistulae (SDAVF) are the most common vascular malformations of the spine. Although digital subtraction angiography (DSA) remains the standard of reference to diagnose and classify vascular spinal lesions, we investigated the clinical value of contrast-enhanced MR angiography (CE-MRA), equipped with TRICKS sequences, in localizing SDAVF before selective catheter angiography and possible subsequent treatment. We studied 16 consecutive patients suspected of harbouring vascular spinal cord malformations and we tried to determine the level and the side of the arterial feeder to the arteriovenous abnormality. In 12 cases the results were compared with DSA and/or possible post-operative findings. In nine cases CE-MRA correctly depicted the origin of the fistula: in particular one patient was treated surgically only on the basis of MRA results. Thanks to its elevated spatial and temporal resolution, spinal contrast-enhanced MRA using TRICKS sequences proved reliable in detecting and localizing the SDAVF arterial feeders and can be used as a guide to subsequent selective DSA examination.

Evolutive study of relapsing-remitting multiple sclerosis with cervical proton magnetic resonance spectroscopy. A case report.

We used quantitative proton magnetic resonance spectroscopy (1H-MRS) to evaluate mean relative concentrations ratios for NAA, Cr, Cho and mI during the study of cervical spinal cord plaques in a relapsing-remitting multiple sclerosis (RRMS). A cervical spine MR exam was repeated five times on the following days for two months starting from the onset of a relapse phase, using a 3T whole-body system, with the voxel placed along the demyelinazation lesion. The quantification results were compared with the healthy metabolites content. Quantitative cervical spectroscopy is a reliable tool and can offer important metabolic information as already used on the brain to evaluate the severity, progression and pathogenesis of multiple sclerosis.

Metabolite Changes in Normal Appearing Cervical Spinal Cord in Two Patients with Multiple Sclerosis. A Proton MR Spectroscopic Analysis.

We describe two cases of multiple sclerosis (MS) analyzed with Proton MR Spectroscopy (1H-MRS) with the voxel placed along the main axis of the normal appearing cervical spinal cord over three main space planes, orthogonally set. Relative concentrations expressed by the absolute concentration ratios of total NAA (tNAA), choline (Cho), myo-inositol (mI) and creatine plus phosphocreatine (Cr) were compared with the metabolites of ten healthy volunteers. We found a significant increase in mI/Cr and a small increase in Cho/Cr in the first patient, whereas the second patient had a decrease in NAA/Cr and NAA/Cho ratios. 1H-MRS will disclose biochemical changes in MS, even in normal appearing spinal cord, as already described in normal appearing cerebral tissue: these biochemical changes may provide significant information on disease prognosis.

Magnetic Resonance Imaging of the Human Spine and Spinal Cord at 3 Tesla A Technical Note

Investigation of the spinal cord with a high field strength MR system is hampered by the inhomogeneous magnetic field, physiological movements and the small size of the anatomical area. We describe normal and pathological neuroradiological findings and the parameters of optimized sequences for use with the new 3T MR systems. Thanks to its high spatial resolution, temporal resolution and signal/noise ratio, use of a 3 Tesla MR device (Signa EXCITE 3T) and a dedicated phased array coil has dramatically improved spine and spinal cord imaging, clearly displaying the anatomic details most difficult to examine. The longer T1 longitudinal tissue relaxation time with 3T MR systems is proportional to the strength of the external magnetic field B0. Tissue contrast between white matter, grey matter, CSF and bone tissue is not optimal with traditional spin echo and/or fast spin echo sequences. Hence they are often replaced by T1 Flair acquisitions (Fast Spin Echo–IR with average inversion times of 800–1000ms) which yield T1 weighted images with satisfactory contrast. Unlike images produced by systems using a lower magnetic field strength, 3T MR T2 sequences are highly diagnostic, disclosing the finest anatomical details.

An ischaemic thalamic lesion extending to the mammillothalamic tract associated with absent ipsilateral mammillary body in a patient with temporal lobe epilepsy. A case report.

We describe a patient with right temporal lobe epilepsy with MR findings of an ischaemic thalamic lesion extending to the mammillothalamic tract and absent visualization of the mammillary body without signal changes in the hippocampus.

Massive Peripheral Nerve Hypertrophy in a Patient with Chronic Inflammatory Demyelinating Polyradiculoneuropathy

We describe a male patient with chronic inflammatory demyelinating polyradiculoneuropathy presenting extensive diffuse hypertrophy of the nerve roots of peripheral nerves. Since adolescence the patient has had a slow and progressive mainly distal loss of sensitivity and muscle weakness in all four limbs. He presented with diffuse muscle atrophy with enlarged palpable nerve trunks. Electromyography disclosed impaired sensory and motor responses in the bilateral median nerves and the right ulnar nerve. CSF examination showed elevated protein content, while MR scans depicted extensive hypertrophy of the spinal nerve roots. The patient benefitted from corticosteroid treatment.

Childhood spinal glioblastoma multiforme with intracranial dissemination. A case report.

Primary spinal cord tumors in children are uncommon and account for approximately 5% of all pediatric central nervous system tumors. Intracranial metastases from primary spinal cord tumors have rarely been reported. Spinal cord glioblastoma in children mainly involves the thoracic region, whereas involvement of the medullaris conus with intracranial dissemination has been described in six cases. This paper describes a pediatric case of thoracic glioblastoma multiforme with intracranial dissemination in the early stage of the clinical course and discuss the clinical and neuroradiological manifestations, the possible patterns of dissemination and finally to consider the therapeutic implications.

3.0 TESLA Magnetic Resonance iconographic study of a patient with demyelinating disease of the cervical spine.

A 43-year-old woman with clinically suspected demyelinating cervical myelopathy complained of paroxysmal episodes of vertigo and dysequilibrium lasting about ten minutes and recurring two to three times a day associated with paraesthesias in the first two fingers of the left hand initially extending to the arm and then to the whole of the left side of the body. Somatosensory evoked potentials indicated impaired central sensory conduction of the legs and left arm. Motor evoked potentials disclosed a pyramidal lesion in the left limbs. Magnetic resonance brain scan showed areas of signal change in the left frontomesial subcortical and ipsilateral peritrigonal regions probably caused by autoimmune inflammatory disease. The patient underwent cervical spine investigation using a 3.0 Tesla magnetic resonance system (Signa Excite, GE Medical Systems) with an eight channel CTL coil.