FLAIR hyperintensity in the subarachnoid space: Main differentials.

The fluid-attenuated inversion recovery (FLAIR) sequence forms part of the vast majority of current diagnostic protocols for brain MRI. This sequence enables the suppression of the signal from cerebrospinal fluid, facilitating the detection of disease involving the subarachnoid space. The causes of hyperintensity in the arachnoid space in this sequence can be divided into two main categories: hyperintensity due to disease and hyperintensity due to artifacts. Hyperintensity due to tumors, inflammation, vascular disease, or hypercellularity of the cerebrospinal fluid or hematic contents is well known. However, numerous other non-pathological conditions, mainly due to artifacts, that are also associated with this finding are a potential source of diagnostic errors.

Clinical-radiological approach to nontraumatic myelopathy. / Enfoque clínico-radiológico de la mielopatía no traumática.

Diseases of the spinal cord often have devastating consequences and imaging studies are indispensable for their diagnosis. The fundamental imaging technique to evaluate these diseases is magnetic resonance imaging of the spine. The diagnostic approach must be based on the clinical context, the time elapsed since the onset of symptoms and signs, and the imaging findings; for this reason, it sometimes necessary to broaden the study to include the brain. The first step in the diagnostic algorithm is to rule out spinal cord compression before evaluating other causes of myelopathy, which sometimes has multiple causes. This paper includes a broad review of the different diseases that can cause myelopathy, their imaging manifestations, their differential diagnoses, and diagnostic algorithms. Using an appropriate radiological approach will result in better management and prognosis of these patients.

Evaluation of the postoperative lumbar spine.

Given the prevalence of low back pain, surgical interventions on the lumbar spine are becoming more common. Among the many surgical procedures available for these interventions, the most common are laminectomy and discectomy. In 10 to 40% of patients who undergo surgical interventions on the lumbar spine, low back pain is not completely alleviated or it recurs, and these cases fall into the category of « failed back surgery syndrome ¼. This syndrome can have many different causes and multiple factors are often involved. It is important not to confuse the normal postoperative findings with those specific to failed back surgery syndrome. Deciding which imaging technique to use will depend on the type of surgical intervention, whether metallic orthopedic material was used, and the clinical suspicion. It is essential to know the advantages and limitations of the available imaging techniques to ensure the optimal evaluation of these patients, especially after interventions carried out with instrumentation to minimize the artifacts due to these materials.