L. Albini Riccioli

Quantitative Cervical Spinal Cord 3T Proton MR Spectroscopy in Multiple Sclerosis

BACKGROUND AND PURPOSE: Brain proton MR spectroscopy (1H-MR spectroscopy) is a useful technique for evaluating neuronal/axonal damage and demyelization in multiple sclerosis (MS). Because MS disability is frequently related to spinal cord lesions, potential markers for MS stage differentiation and severity would require in vivo quantification of spinal integrity. However, few spectroscopy studies have investigated cervical disease due to technical difficulties. The present study used 3T 1H-MR spectroscopy to measure the main metabolites in cervical spinal cord plaques of a group in patients with relapsing-remitting MS (RRMS) and compared them with metabolite measurements in healthy volunteers. MATERIALS AND METHODS: A 1H-MR point-resolved spectroscopy sequence volume of interest was prescribed along the main axis of the cord between C2 and C3 levels on a plaque in a group of 15 patients with RRMS for a total acquisition time of approximately 14 minutes. MR spectroscopy data were analyzed by the user-independent fitting routine LCModel, and relative metabolite concentrations were expressed by the absolute concentration ratios. A Student t test was used to evaluate the difference compared with the healthy metabolite content previously published. RESULTS: We found a significant decrease of total N-acetylaspartate/choline and an increase in choline/creatine and myo-inositol/creatine content on MS plaques in comparison with healthy cervical spine tissue. CONCLUSIONS: In vivo 1H-MR spectroscopy, if confirmed by other similar studies, should be as reliable for clinical studies as it is in brain imaging. Moreover, 1H-MR spectroscopy allows examination of spinal cord integrity at a biochemical level and may be sensitive to subtle changes occurring during the course of MS disease.

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.

Neuroradiological Diagnostic Tools: New MRI Perspectives

MR angiography5,17 is traditionally divided into “non-contrast enhanced” (NCE MRA) and “contrast-enhanced” (CE MRA) techniques. Contrast-enhanced techniques were initially developed to solve some of the problems encountered with non-contrast-enhanced methods, namely the long examination times, pulsatile flow artefacts, saturation when the mean blood flow is slow or when the imaging slice is parallel to the vessel, the characteristic problems of time of flight (TOF) acquisitions, and the need to define a priori beforehand the velocity sensitivity for phase contrast (PC) acquisitions. Currently used contrast-enhanced techniques 7,8,15,18 are based on the acquisition of 3D gradient-echo sequences synchronized at the first passage of contrast medium by different strategies (detection of a test bolus injection, automated triggering, fluoroscopic imaging). Basically, contrast medium is administered to counteract saturation induced by slow blood flow or flow directed parallel to the imaging slice. Contrast medium serves to obtain a “static” image of vascular structures with acquisitions times ranging from a few seconds to 1–2 minutes. To avoid venous contamination, different methods have been used to collect data (centric-approach, elliptical-centric phase encoding order, etc.) in an attempt to record first the information relating to low spatial frequencies (contrast data) with respect to high spatial frequencies (detail and contour data).

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.

Potential Impact of Advanced 3 Tesla Diagnostics in the Management of Patients with Brain Tumours

A General Electric 3 Tesla Signa Excite system was installed in the Neuroradiology Unit of Bellaria Hospital, Bologna in February 2004. In line with current legislation, we designed a clinical research project to assess the practical impact of the new device on the investigation of brain tumours, the pituitary gland, rare neurological diseases, epilepsy, multiple sclerosis and Parkinsons disease. We describe our preliminary anecdotal findings in the study of brain tumours and the potential impact of 3 T imaging on the preparation and management of neurosurgical candidates. One decisive result to emerge is that the greater awareness of the risks and difficulties entailed in surgical resection help the neurosurgeon establish a more clear-cut relationship with patients on seeking their informed consent. By understanding and accepting the risks involved, we hope to curb the increasing number of legal disputes caused by surgical complications.

3-Tesla Study of the Spinal Cord White Matter

Spinal cord as soon as brain, can be affected by dysmyelinating and demyelinating diseases, as Multiple Sclerosis (MS), Acute Disseminated Encephalomyelitis (ADEM), Neuromyelis Optica (NMO) and Transverse Myelitis. 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 in spinal cord white matter and the parameters of optimized sequences for use with the 3T MR systems.

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 Tesla MR study of cerebellar medulloblastoma

Medulloblastoma belongs to the group of highly malignant neuroepithelial tumours and is the commonest tumour in childhood (average age nine years) followed by astrocytoma1. Medulloblastoma usually arises in the posterior fossa, namely the cerebellar vermis, and more seldom in the fourth ventricle, supratentorium and spinal cord. We describe the 3 Tesla magnetic resonance (MR) features of a medulloblastoma located in the right cerebellar hemisphere adhering to the tentorium in a 16-year-old male.