1. To be familiar with the practical basics of MRI SWI sequences.
2. To learn what information we can get from the SWI sequence.
3. To understand the importance of applying the SWI technique in individual patients.
Susceptibility weighted imaging (SWI) is increasingly used in clinical routine and is useful notably for the detection of hemosiderin (in a variety of hemorrhagic conditions) as well as iron deposition (in a variety of neurodegenerative diseases). The first part will discuss the essential technical aspects of SWI, and how imaging parameters will influence imaging contrast and consequently image analysis and results. The second part will assess imaging, interpretation and implications and notably the differential diagnosis of cerebral microbleeds, which occur in a variety of conditions including arterial hypertension, cerebral amyloid angiopathy (CAA), CADASIL (Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy), trauma (hemorrhagic diffuse axonal injury DAI) and brain irradiation. The third part will discuss imaging of the nigrosome 1 of the substantia nigra, also known as swallowtail sign, as an imaging marker of Parkinson Disease and Dementia with Lewy bodies. The final fourth part will discuss applications of SWI in a variety of vascular and neurodegenerative disorders including NBAI (neurodegeneration with brain iron accumulation), ASL (amyotrophic lateral sclerosis), clot imaging in acute stroke, and iron deposition during ageing.
1. To learn the principals of DTI imaging in neuroradiology.
2. To appreciate the practical value of DTI in different neurological disorders.
3. To be familiar with pitfalls of DWI and DTI imaging - common language with neurosurgeons.
Diffusion Tensor Imaging provides in vivo visualisation of white matter tracts by voxel x voxel mapping of the anisotropy and local direction of fibres. Conventional MR imaging is limited to detecting macroscopic brain changes, while DTI quantifies diffusion characteristics within microscopic nerve fibre bundles and is thought to represent axon density, diameter, and continuity, myelin and interstitial water content. Due to recent advances in the technical design of sequences a DTI study of the brain with 64 directions and 1.8 mm voxel size can be obtained in 5 minutes with a 3T MR unit. Therefore DTI can be easily included in routine clinical MR protocols. There are no standardised approaches in DTI pre and postprocessing despite the availability of proprietary software and several freely distributed software packages providing good quality tractography of the bran white matter bundles. The easiest implementation of DTI in clinical practice is based on deterministic tractography, which provides an acceptable reproducibility in the identification and quantitative analysis of the brain white matter bundles through a rather standardised approach. Common clinical applications of DTI in single subjects are represented by brain neoplasms, neurodegenerative disorders and traumatic brain injuries. DTI-based tractography is widely used for presurgical planning and is a powerful tool in the evaluation of major WM fibre bundles; it has also a positive impact on neurosurgical resection, disease prognosis, and preservation of brain function.