Magnetic resonance images are acquired by combining images obtained using
two different spatial sensitivity profiles, 1', 2'. The transverse
magnetisation is caused to adopt such a profile 1' in one direction,
resulting, in two dimensions, to a series of alternating stripes of
respectively strong and weak, e.g. zero, transverse magnetisation. The
regions of strong transverse magnetisation correspond to regions of high
sensitivity in the acquired image. A complementary sensitivity profile 2'
is stored as longitudinal magnetisation. A first image is then acquired
in which the pixels are centered on the regions of high sensitivity
within the first sensitivity profile 1'. The complementary sensitivity
profile 2' is then recalled by inserting an additional gradient pulse and
then a radio-frequency pulse into the pulse sequence and a second image
acquired. As with the first image, the pixels are centered on the
high-sensitivity regions, but these are mid-way between those within the
first sensitivity profile 1'. A combined image is then created by
interleaving the two images. The combined image has twice the resolution
of each of the two component images. In a further embodiment, two images
are acquired in which each spatial sensitivity profile exhibits a
sinusoidal profile extending over the field of view. In this case, all
the data from the two images are combined using an algorithm.
