"Basically, an inversion recovery (IR) pulse sequence is a spin echo pulse sequence preceded by a 180° RF pulse. The preparatory pulse inverts longitudinal magnetisation (Mz), namely, it flips Mz to its negative value, -Mz. Tissues regain Mz at different longitudinal (T1) relaxation rates determined by their T1 relaxation times. The spin echo 90° readout pulse is applied at the exact time when longitudinal magnetisation reaches the null point for the tissue we wish to suppress.The time elapsed between the preparatory 180° pulse and the 90° excitation (slice selection) RF pulse is termed time to inversion (TI) (figure 1)."
"Virtually all IR spin echo sequences use magnitude reconstruction for the final image. What this means is that pixel intensity reflects only the magnitude of longitudinal magnetisation, disregarding polarity; absolute values (i.e. absolute distances from the null point) are used.The little-used phase-sensitive inversion recovery (PSIR) reconstruction method, by contradistinction, takes polarity into account, rendering pixels with negative Mz values darker and vice versa."
"increase in flow-related artifacts, such as flow voids."
"Basically, an inversion recovery (IR) pulse sequence is a spin echo pulse sequence preceded by a 180° RF pulse. The preparatory pulse inverts longitudinal magnetisation (Mz), namely, it flips Mz to its negative value, -Mz. Tissues regain Mz at different longitudinal (T1) relaxation rates determined by their T1 relaxation times. The spin echo 90° readout pulse is applied at the exact time when longitudinal magnetisation reaches the null point for the tissue we wish to suppress.The time elapsed between the preparatory 180° pulse and the 90° excitation (slice selection) RF pulse is termed time to inversion (TI) (figure 1)."
"Basically, an inversion recovery (IR) pulse sequence is a spin echo pulse sequence preceded by a 180° RF pulse. The preparatory pulse inverts longitudinal magnetisation (Mz), namely, it flips Mz to its negative value, -Mz. Tissues regain Mz at different longitudinal (T1) relaxation rates determined by their T1 relaxation times. The spin echo 90° readout pulse is applied at the exact time when longitudinal magnetisation reaches the null point for the tissue we wish to suppress.The time elapsed between the preparatory 180° pulse and the 90° excitation (slice selection) RF pulse is termed time to inversion (TI) (figure 1)."
"relatively insensitive to magnetic field inhomogeneity (cf. SPIR/SPAIR)"
"relatively insensitive to magnetic field inhomogeneity (cf. SPIR/SPAIR)"
"Basically, an inversion recovery (IR) pulse sequence is a spin echo pulse sequence preceded by a 180° RF pulse. The preparatory pulse inverts longitudinal magnetisation (Mz), namely, it flips Mz to its negative value, -Mz. Tissues regain Mz at different longitudinal (T1) relaxation rates determined by their T1 relaxation times. The spin echo 90° readout pulse is applied at the exact time when longitudinal magnetisation reaches the null point for the tissue we wish to suppress.The time elapsed between the preparatory 180° pulse and the 90° excitation (slice selection) RF pulse is termed time to inversion (TI) (figure 1)."
"Basically, an inversion recovery (IR) pulse sequence is a spin echo pulse sequence preceded by a 180° RF pulse. The preparatory pulse inverts longitudinal magnetisation (Mz), namely, it flips Mz to its negative value, -Mz. Tissues regain Mz at different longitudinal (T1) relaxation rates determined by their T1 relaxation times. The spin echo 90° readout pulse is applied at the exact time when longitudinal magnetisation reaches the null point for the tissue we wish to suppress.The time elapsed between the preparatory 180° pulse and the 90° excitation (slice selection) RF pulse is termed time to inversion (TI) (figure 1)."
Expected headings
"Physics"
"Image reconstruction"
"Advantages"
"Drawbacks"
"Inversion recovery pulse sequences are a type of MRI sequence used to selectively null the signal for certain tissues (e.g. fat or fluid)."
"Basically, an inversion recovery (IR) pulse sequence is a spin echo pulse sequence preceded by a 180° RF pulse. The preparatory pulse inverts longitudinal magnetisation (Mz), namely, it flips Mz to its negative value, -Mz. Tissues regain Mz at different longitudinal (T1) relaxation rates determined by their T1 relaxation times. The spin echo 90° readout pulse is applied at the exact time when longitudinal magnetisation reaches the null point for the tissue we wish to suppress.The time elapsed between the preparatory 180° pulse and the 90° excitation (slice selection) RF pulse is termed time to inversion (TI) (figure 1)."
"Virtually all IR spin echo sequences use magnitude reconstruction for the final image. What this means is that pixel intensity reflects only the magnitude of longitudinal magnetisation, disregarding polarity; absolute values (i.e. absolute distances from the null point) are used.The little-used phase-sensitive inversion recovery (PSIR) reconstruction method, by contradistinction, takes polarity into account, rendering pixels with negative Mz values darker and vice versa."
"twice the dynamic range of T1W spin echo sequences; due to the 180° inverting pulse, longitudinal relaxation goes from -Mz to Mz"