Absolute thermometry using hyperpolarized ¹²⁹ Xe free-induction decay and spin-echo chemical-shift imaging in rats.

<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:semantics> <mml:mrow><mml:msup><mml:mrow/> <mml:mrow><mml:mn>129</mml:mn></mml:mrow> </mml:msup> </mml:mrow> <mml:annotation>$$ {}^{129} $$</mml:annotation></mml:semantics> </mml:math> Xe MRI using conventional CSI and turbo spectroscopic imaging of lipid-dissolved <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:semantics> <mml:mrow><mml:msup><mml:mrow/> <mml:mrow><mml:mn>129</mml:mn></mml:mrow> </mml:msup> </mml:mrow> <mml:annotation>$$ {}^{129} $$</mml:annotation></mml:semantics> </mml:math> Xe enables precise temperature measurements in the rat's abdomen using both FID and spin-echo acquisitions with acquisition of spin echoes enabling most precise temperature measurements.