Diagnosis of neuromyelitis optica (NMO) spectrum disorders: is MRI obsolete?

INTRODUCTION: Neuromyelitis optica (NMO) is a severe demyelinating disease that preferentially involves spinal cord and optic nerve. It is part of a spectrum of neurological conditions associated with antibodies to aquaporin-4 (AQP4). This study investigates the role of MRI where novel, more sensitive AQP4 antibody immunoassay techniques are being used. METHODS: Retrospective review of neuroimaging in 69 patients (25 antibody positive, 44 antibody negative), investigated in the context of suspected NMO or NMO spectrum disorder, was performed independently by two consultant neuroradiologists. RESULTS: Longitudinally extensive, central spinal cord lesions were more frequent in AQP4 positive patients (95.2% vs 35.5%, p < 0.0001; 85.7% vs 45.2%, p = 0.015). Multiple sclerosis diagnostic criteria were less frequently fulfilled on brain MRI in antibody positive patients (5.6% vs 33.3%, p = 0.035). Juxtacortical and corpus callosal lesions were also less common in this group (16.7% vs 46.7%, p = 0.063; 5.6% vs 46.7%, p = 0.0034). Hypothalamic and periependymal disease related to the aqueduct was not seen in antibody negative patients. T1 hypointensity was more common in cord lesions of antibody positive patients (75.0% vs 35.3%, p = 0.037). However, this characteristic did not discriminate antibody positive and negative longitudinally extensive cord lesions (73.3% vs 62.5%, p = 0.66). CONCLUSION: The NMO spectrum of diseases are among an increasing number of neurological conditions defined by serological tests. However, despite improved immunoassay techniques, MRI of the brain and spinal cord continues to be among the first-line investigations in these patients, providing valuable diagnostic information that will help guide patient management.

Imaging of the calvarium.

The skull vault consists of a multitude of flat bones held together by the cranial sutures. Radiologists encounter a vast array of calvarial pathologies that tend to cause abnormalities in thickness, abnormalities in density, focal defects, or an excess of soft tissue or bone tissue. Further anomalies related to the cranial sutures and fontanelles occur in the dynamic pediatric skull. The imaging features of the host of conditions resulting in these commonly detected calvarial abnormalities are reviewed and illustrated.

StarClose vascular closure device: prospective study on 222 deployments in an interventional radiology practice.

The StarClose device (Abbott Vascular Devices; Abbott Laboratories, Redwood City, CA) utilizes an externally placed Nitinol clip to achieve arterial closure following femoral artery puncture. The objectives of this study were to assess the efficacy and complications of the StarClose device in patients undergoing interventional radiological procedures. Preprocedural clotting status, pulse and blood pressure, severity of vessel calcification, sheath size, and time to deployment were recorded. Postdeployment complications immediately postprocedure, at 1 h, at 2 h, and at 1 week were recorded. A duplex scan was performed in the first 10 patients to assess any immediate vascular complications. Deployments were successful in 96% achieving immediate hemostasis. Mean deployment time was 48 s. There were no major complications. The StarClose device was found to have a high technical and clinical efficacy.

Endovascular removal of long-term hemodialysis catheters.

Central venous catheters that have been in place for a long time can become fixed to the vein wall, making them impossible to pull out. Leaving them in situ is undesirable because of the risk that they could act as a nidus for thrombosis. Moreover, inserting new catheters alongside the old ones might compromise flow in the superior vena cava, further predisposing to thrombosis. Surgical removal is likewise undesirable, as this would necessitate thoracotomy with the attendant risks. We describe a novel technique, which we were able to use to remove retained long-term hemodialysis catheters in a patient who needed new catheters and who would have been a high-risk candidate for surgery. The right internal jugular vein was punctured adjacent to the site of insertion and a guide wire was used to form a snare, which was passed around the catheters and used to saw through the fibrous attachments to the vein wall. The midsection of one catheter could not be freed but the snare was used to cut off the proximal and distal ends, which could then be removed, the latter via the femoral vein. New catheters were then inserted via the left internal jugular vein. This technique enabled successful catheter extraction and replacement in a patient who would have been a poor candidate for cardiothoracic surgery.