Echoplanar imaging

The gradient echo sequence equivalent to a fast spin echo sequence is obtained by rapidly applying, or blipping, a series of rephasing gradients following the excitation pulse and dephasing gradient. Gradient blipping is done extremely rapidly (< 1 ms), and up to 128 echoes can be generated from a single excitation. Clearly, the advantage of such echoplanar imaging is the speed of acquisition. Multislice images of the entire cortex, with slice thickness of only a few millimetres, can be acquired in 3 s or less. Such high-speed imaging is highly desirable for functional MRI, where we wish to detect physiologically determined changes in magnetic resonance signal with the best possible temporal resolution. However, the hardware required for rapid gradient blipping has only become available on clinical machines in the last few years.

Breaking Bulimia

Breaking Bulimia

We have all been there: turning to the refrigerator if feeling lonely or bored or indulging in seconds or thirds if strained. But if you suffer from bulimia, the from time to time urge to overeat is more like an obsession.

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