Dynamic MRI in the evaluation of the spine: state of the art.

INTRODUCTION: Degenerative disease of the spine is a generic term encompassing a wide range of different disease processes, which leads to spinal instability; traumatic/neoplastic events can accelerate this aging process. Therefore, the dynamic nature of the spine and its mobility across multiple segments is difficult to depict with any single imaging modality. METHODS: A review of PubMed databases for articles published about kMRI in patients with cervical and lumbar spinal desease was performed. We focused on the physiopathological changes in the transition from supine to upright position in spine instability. DISCUSSION: Until a few years ago, X-ray was the only imaging modality for the spine in the upright position. Of the imaging techniques currently available, MRI provides the greatest range of information and the most accurate delineation of soft-tissue and osseous structures. Conventional MRI examinations of the spine usually are performed in supine position, in functional rest, but the lumbar spine instability is often shown only by upright standing. This can result in negative findings, even in the presence of symptoms. Regardless, the final result is distorted. To overcome this limitation, Kinetic MRI (kMRI) can image patients in a weight-bearing position and in flexed and extended positions, thus revealing abnormalities that are missed by traditional MRI studies. CONCLUSION: Despite some limitations, the upright MRI can be a complementary investigation to the traditional methods when there are negative results in conventional MRI in symptomatic patients or when surgical therapy is scheduled.

Effects of serial macrocyclic-based contrast materials gadoterate meglumine and gadobutrol administrations on gadolinium-related dentate nuclei signal increases in unenhanced T1-weighted brain: a retrospective study in 158 multiple sclerosis (MS) patients.

PURPOSE: To perform T1 signal intensity (SI) measurements in the dentate nuclei of adult patients with confirmed multiple sclerosis (MS) after serial administrations of the macrocyclic gadolinium-based contrast agents (GBCAs), gadoterate meglumine and gadobutrol. MATERIALS AND METHODS: This retrospective study was approved by the institutional review board and informed consent was waived. A review of our PACS database for the period from March 1, 2007 to July 31, 2016 revealed 158 confirmed MS patients who received exclusively either gadoterate meglumine (n = 81) or gadobutrol (n = 77) for diagnosis and follow-up. SI measurements on unenhanced T1-weighted images were performed on all scans of all patients and at regions of interest (ROIs) positioned on the dentate nucleus (DN) and pons. The dentate nucleus-to-pons (DNP) T1-SI ratio was subsequently calculated. Unpaired T test and regression analysis were used to evaluate statistical differences. RESULTS: An increase in DNP was noted between the first and last MR examinations for both gadoterate meglumine (0.0032 ± 0.0216) and gadobutrol (0.0019 ± 0.0346). Although the differences were not statistically significant based across the entire patient population, visible T1 hyperintensity in the DN was noted in approximately one-third of all patients in each group that received at least five administrations of either GBCA. CONCLUSIONS: SI increases on unenhanced T1-weighted images possibly indicative of gadolinium retention occur after serial administrations of the macrocyclic GBCAs, gadoterate meglumine and gadobutrol.

Systemic metastases from central nervous system ependymoma: case report and review of the literature.

Ependymal tumours in adults are rare, accounting for less than 4% of primary tumours of the central nervous system, and exceptionally metastasise outside the nervous system. In this study, we present a case of anaplastic ependymoma, which developed metastases outside the nervous system less than a year after its clinical onset. A healthy 65-year-old woman suddenly presented with drowsiness of unknown origin, accompanied by ingravescent fatigue, inability to maintain the upright posture, headache, nausea and vomiting. Computed tomography study performed in the emergency department showed the presence of an inhomogeneously hypodense area, with temporoparietal extension and median line deviation. After surgical excision, performed after two days, the bioptic examination demonstrated an anaplastic ependymoma with multiple areas of necrosis. The patient was submitted to adjuvant radiation therapy. At magnetic resonance imaging follow-up, performed three months after surgery, neither local recurrences nor typical 'drop metastases' to the spinal area were observed. Three months later, magnetic resonance imaging control revealed bone metastases and recurrences in the left insula and at the ipsilateral cerebellar hemisphere. Total body computed tomography examination showed metastases in the liver, vertebrae and pelvic bones, and involvement of paratracheal lymph nodes.

Vascular malformation mimicking multiple sclerosis active plaque: Usefulness of susceptibility weighted imaging (SWI) to perform correct diagnosis.

Brain focal hyperdensity areas are common findings in computed tomography examinations, often further evaluated in magnetic resonance imaging exams. These are usually haemosiderin and calcified perivascular clusters known as cerebral microbleeds and may be secondary signs of brain disorders. Cerebral microbleeds are paramagnetic and ferromagnetic substances determining magnetic field inhomogeneity. Susceptibility weighted imaging (SWI) performed at 3T with phase post-processing is very useful in evaluating this field variation. In fact in the past decade SWI has been increasingly reported for its clinical value in adults with neurologic disorders, traumas, arterial venous malformations, occult venous diseases, tumours and functional brain imaging. The occasional computed tomography findings of single or multiple focal hyperdense areas can mimic many of these brain disorders and lead to misinterpretations. For these reason it is useful to have a more detailed diagnosis with MRI brain examination. The authors highlight the role of SWI sequence in the differential diagnosis among active plaque, vascular malformation and haemorrhagic lesion in a case report of a 41-year-old woman suffering from multiple sclerosis with a focal hyperdense area reported in a computed tomography brain examination.

T2 shine-through phenomena in diffusion-weighted MR imaging of lumbar discs after oxygen-ozone discolysis: a randomized, double-blind trial with steroid and O2-O3 discolysis versus steroid only.

PURPOSE: To evaluate the discal morpho-structural changes as predictive sign in the clinical outcome after Ozone Therapy in lumbar disc herniation using the T2 shine-through effect in DWI. METHODS: One hundred and fifty-four patients suffering from lumbosciatica (89 men and 65 women; range 23-62 years) were included in previous MR study performed with FSE-T2 and T2-fat, SE-T1 and DWI sequences and were randomly assigned to two groups. Seventy-seven patients (Control Group) underwent conservative treatment with intraforaminal injection of steroid and anesthetic. The remaining 77 patients (Study Group) underwent the same treatment with the addiction of oxygen-ozone (O2-O3). During the coming 6 months, an MRI follow-up with the same sequences was performed. An intervertebral disc volumetric analysis (IDVA), DWI signal score and post treatment clinical outcome evaluation were performed for an assessment of hernia reduction. χ (2) test, Student's t test and analysis of covariance were used for comparison of variables. RESULTS: In the Study Group, 58 over 77 patients had a successful outcome (Responders). In the Responders group, DWI T2 shine-through effect was present during MRI follow-up and in particular in 53 of 77 patients in the 6 months of follow-up (P < 0.05). Moreover, in the same group was present a statistically significant discs' shrinkage in the sixth month of follow-up (P < 0.05) as showed by IDVA. CONCLUSIONS: T2 shine-through effect in DWI is present before morphological disc reduction and moreover could be considered as a predictive sign of response to oxygen-ozone treatment.