tailieunhanh - Ebook FRCR 2B Viva-A case-based approach: Part 2

(BQ) Part 2 book "FRCR 2B Viva-A case-based approach" presents the following contents: Neurological imaging, urogynaecological imaging, paediatric imaging, radionuclide imaging. Invite you to consult. | 4. Introduction to Neurological Imaging Aarti Shah and Nagachandar Kandasamy Anecdotal experience suggests that all candidates will be tested on neuroradiology as part of their viva with MRI playing a larger role here than in other organ systems. Basic approach to brain MRI Q Briefly look at all of the films to see what sequences were performed in which plane and whether there are any postcontrast images as this may provide a clue to the pathology. Remember that although the axial plane is the primary plane for neuroimaging orientation may often be a clue to the underlying pathology for example coronal views are always performed when evaluating the sella as well as temporal lobe anatomy for refractory seizures. Sagittal views are useful for midline lesions third ventricle sella pineal region and corpus callosum as well as the brainstem and cerebellar vermis. On T1-weighted images fat appears bright and therefore the myelin sheaths of white matter appear brighter than grey matter. T1-weighted images are most useful for anatomical detail and usually contrast-enhanced sequences tend to be T1-weighted. Do not assume that hyperintensity on a postcontrast sequence is enhancement always check with the noncontrast images to confirm. c The signal intensity on T2-weighted imaging depends on water content and as fat is darker than on T1-weighted imaging white matter appears darker than grey matter on this sequence. T2-weighted images are most sensitive for detecting pathology and therefore most basic protocols will include a T2-weighted and a fluid-attenuated inversion recovery FLAIR sequence. FLAIR images are T2-weighted with the cerebrospinal fluid CSF signal suppressed and are particularly helpful in the assessment of periventricular lesions. Contrast does not enhance rapidly flowing blood so different techniques such as gradient-echo and magnetic resonance angiography are used for the evaluation of vascular structures. Due to the magnetic susceptibility of blood .