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Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is a recently defined inflammatory central nervous system disorder responsive to steroids with characteristic magnetic resonance imaging (MRI) features. We report a 69-year-old man presenting with gait ataxia with the characteristic MRI features of CLIPPERS and describe the clinical, MRI, and magnetic resonance spectroscopy (MRS) follow-up after treatment with glucocorticosteroids. Brain and spine MRI showed punctate enhancement peppering the brainstem, cerebellar peduncles, and upper cervical cord. In MRS, the ratio of N-acetyl aspartate to creatine (NAA/Cr) was significantly decreased in the pons and both thalami. An extensive evaluation found no alternative diagnoses. Treatment with steroids led to rapid clinical improvement. Repeat MRI and MRS showed complete resolution of gadolinium-enhancing lesions and recovery of NAA/Cr levels in the pons and thalami. After 1 month of tapering oral steroids, weekly oral methotrexate was started and the patient has remained stable for the past 6 months.

Objective: To evaluate the usefulness of diffusion tensor imaging (DTI) in the clinical setting as a complementary tool to conventional MRI in the study and assessment of the sciatic nerve and its pathologies. Methods: 17 patients diagnosed with different types of sciatic neuropathy and 10 healthy controls underwent a conventional MRI and a DTI study in a 3-T MR scanner (Achieva® 3-T X-Series; Philips Healthcare, Netherlands). Results: In the control group, we were able to track and visualize the common sciatic nerve and its main branches from hip to foot. In the patient group, the affected sciatic nerves presented statistically significant lower fractional anisotropy values and higher apparent diffusion coefficient values when compared with controls, suggesting nerve damage. In all cases, DTI offered complementary information for diagnosis and/or confirmation of the suspected pathology. When compared with conventional MRI, DTI showed higher sensitivity for nerve damage detection. Conclusion: DTI offers a significant improvement and an important complement to visualize the sciatic nerve and its main branches. In patients with sciatic nerve pathology DTI allows to a better detection and characterization of the nerve damage. Advances in knowledge: DTI enables in vivo dissection of the sciatic nerve white matter fibres; its use offers a significant improvement and complement to conventional MRI.

ISBN: 978-145771303-3International audienceThis paper presents an algorithm for a 3D segmentation of the aorta artery in magnetic resonance images (MRI). The purpose is to project the 3D segmented aorta in the patient's abdomen with an augmented reality (AR) system to help the surgeon in laparoscopic interventions. In order to obtain accurate results in the segmentation process a marker-controlled watershed algorithm is used. Since this method requires a robust gradient image and two marker sets, a preprocessing step is carried out in each image. The algorithm is automatic and the results are promising with a Jaccard coefficient (JC) of 0.8107 ± 0.0228