Rapid and accurate measurement of transverse relaxation times using a single shot multi-echo echo-planar imaging sequence.
Methods for making rapid and accurate measurements and maps of the transverse relaxation time from a single free induction decay (FID) are proposed. The methods use a multi-echo sequence in combination with B1 insensitive (hyperbolic secant or BIREF2b) refocusing pulses and rapid echo-planar imaging techniques. The results were calibrated against a single spin echo echo-planar imaging sequence using a phantom containing a range of CuSO4 concentrations. The mean percentage absolute difference between the multi-echo and single-echo results was 3% for the multi-echo sequence using the hyperbolic secant refocusing pulse, and 7% for the multi-echo sequence using the BIREF2b refocusing pulse, compared to 13% for a multi-echo sequence using a nonselective sinc refocusing pulse. The use of the sequences in vivo has been demonstrated in studies of gastric function, i.e., the measurement of gastric dilution and monitoring of formation of a raft of alginate polysaccharide within the stomach.
Tyler
Damian J
DJ
Magnetic Resonance Centre, School of Physics & Astronomy, University of Nottingham, NG7 2RD, UK.
Moore
Rachel J
RJ
Marciani
Luca
L
Gowland
Penny A
PA
D000464:Alginates / Q000008:administration & dosage; D000536:Aluminum Hydroxide / Q000008:administration & dosage; D000863:Antacids / Q000008:administration & dosage; D019327:Copper Sulfate; D004338:Drug Combinations; D017352:Echo-Planar Imaging / Q000379:methods*; D005772:Gastrointestinal Transit / Q000502:physiology*; D006801:Humans; D019047:Phantoms, Imaging; D011134:Polysaccharides / Q000008:administration & dosage; D012824:Silicic Acid / Q000008:administration & dosage; D017693:Sodium Bicarbonate / Q000008:administration & dosage
D000464:Alginates; D000863:Antacids; D004338:Drug Combinations; D011134:Polysaccharides; D012824:Silicic Acid; D000536:Aluminum Hydroxide; C007829:alginate, aluminium hydroxide, magnesium trisilicate, sodium bicarbonate drug combination; D017693:Sodium Bicarbonate; D019327:Copper Sulfate