From images to insights: a neuroradiologist's practical guide on white matter fiber tract anatomy and DTI patterns for pre-surgical planning.

INTRODUCTION: Diffusion tensor imaging (DTI) is a valuable non-invasive imaging modality for mapping white matter tracts and assessing microstructural integrity, and can be used as a "biomarker" in diagnosis, differentiation, and therapeutic monitoring. Although it has gained clinical importance as a marker of neuropathology, limitations in its interpretation underscore the need for caution. METHODS: This review provides an overview of the principles and clinical applicability of DTI. We focus on major white matter fiber bundles, detailing their normal anatomy and pathological DTI patterns, with emphasis on tracts routinely requested in our neurosurgical department in the preoperative context (uncinate fasciculus, arcuate fasciculus, pyramidal pathway, optic radiation, and dentatorubrothalamic tract). RESULTS: We guide neuroradiologists and neurosurgeons in defining volumes of interest for mapping individual tracts and demonstrating their 3D reconstructions. The intricate trajectories of white matter tracts pose a challenge for accurate fiber orientation recording, with each bundle exhibiting specific characteristics. Tracts adjacent to brain lesions are categorized as displaced, edematous, infiltrated, or disrupted, illustrated with clinical cases of brain neoplasms. To improve structured reporting, we propose a checklist of topics for inclusion in imaging evaluations and MRI reports. CONCLUSION: DTI is emerging as a powerful tool for assessing microstructural changes in brain disorders, despite some challenges in standardization and interpretation. This review serves an educational purpose by providing guidance for fiber monitoring and interpretation of pathological patterns observed in clinical cases, highlighting the importance and potential pitfalls of DTI in neuroradiology and surgical planning.

Carotid free-floating thrombus in patients with acute ischaemic stroke and active cancer.

In patients with ischaemic stroke, a carotid free-floating thrombus (CFFT) raises diagnostic and therapeutic challenges. We describe two women, each taking tamoxifen for invasive non-metastatic breast cancer, who developed large-vessel occlusion ischaemic strokes. The first had a CFFT 24 hours after receiving intravenous thrombolysis and mechanical thrombectomy; the thrombus completely resolved after 1 week of therapeutic anticoagulation. The second had a tandem occlusion with a CFFT at admission; her neurological deficits rapidly improved after intravenous thrombolysis without needing a mechanical thrombectomy. However, subsequently, under therapeutic anticoagulation, distal migration of the CFFT caused a recurrent large vessel occlusion ischaemic stroke, requiring mechanical thrombectomy. The CTFF in both cases appeared to relate to a cancer-related prothrombotic state. Both received long-term oral anticoagulation and their tamoxifen was switched to anastrozole. At 3 months, both were functionally independent without recurrent vascular events.

Vertebral artery dissection as the underlying cause of ventral spinal epidural haematoma.

Spontaneous spine epidural haematoma is a rare occurrence, with an incidence of 0.1/100 000 inhabitants/year. The anterior location of the haematoma is very uncommon since the dural sac is firmly attached to the posterior longitudinal ligament. Vertebral artery dissection as its underlying cause is an exceptionally rare event, with only two documented cases.This article presents the case of young woman who arrived at the emergency room with a spinal ventral epidural haematoma extending from C2 to T10, caused by a non-traumatic dissecting aneurysm of the right vertebral artery at V2-V3 segment. Since the patient was tetraparetic, she underwent emergent laminectomy, and the vertebral artery dissection was subsequently treated endovascularly with stenting.Vertebral artery dissection with subsequent perivascular haemorrhage is a possible cause of spontaneous spine epidural haematoma, particularly when located ventrally in the cervical and/or high thoracic column. Hence the importance of a thorough investigation of the vertebral artery integrity.