[Turbo-spin-echo MR imaging of the brain at 0.5 T]

Turbo-spin-echo (TSE) imaging is a fast technique, which provides true spin-echo contrast in a definitely shorter scan time than conventional spin-echo (SE). Clinical studies at 1.5 T show that TSE is a valuable alternative to SE and will ultimately replace time-consuming T2-weighted SE imaging for examinations of the brain and brainstem. Besides the reduction of scan time, TSE is less sensitive to motion artefacts. A slight decrease of susceptibility effects of 1.5 T can be a disadvantage in the detection of old haemorrhagic lesions and calcifications. In these cases the gradient-echo sequence will remain the most sensitive. TSE allows a greater flexibility of examination strategies, including several orientations, strongly T2-weighted images and high spatial resolution (HR) MRI. HR MRI using thin slices (1-3 mm), a small field of view and a 512 image matrix yields detailed information about small anatomical regions (e.g. the pituitary fossa, cavernous sinus, internal auditory canal and brainstem) and permits the delineation of specific cranial nerves. In this study TSE was utilized at 0.5 T field strength in order to assess whether the advantages of TSE hold for midfield systems. Preliminary results in imaging of the brain and brainstem are very promising.