title: Respiratory self-gated multiple gradient recalled echo sequence for free-breathing abdominal R2* mapping.
abstract: Abdominal effective transverse relaxation rate (R(2)*) mapping is critical for a wide range of applications. However, respiratory motion can lead to significant image quality deterioration and R(2)* overestimation. For this work, we explored the feasibility of combining respiratory self-gating techniques with a multiple gradient-recalled echo sequence for free-breathing abdominal R(2)* measurements. In a series of eight normal volunteers, respiratory self-gated-multiple gradient-recalled echo methods effectively avoided motion artifacts to produce quantitative R(2)* measurements in liver, spleen, and kidneys that were comparable to R(2)* measurements produced while breath-holding. Respiratory self-gated-multiple gradient-recalled echo methods demonstrated the potential to avoid the need for breath-holding during abdominal R(2)* mapping. For clinical application, respiratory self-gated-multiple gradient-recalled echo approaches could be particularly useful for R(2)* measurements in those patients unable or unwilling to sustain sufficiently long breath-holds to avoid motion artifacts.
authors.affiliation: Department of Biomedical Engineering, Northwestern University Chicago, Illinois, USA.
authors.forename: Ning
authors.initials: N
authors.lastname: Jin
authors.forename: Zhuoli
authors.initials: Z
authors.lastname: Zhang
authors.forename: Longjiang
authors.initials: L
authors.lastname: Zhang
authors.forename: Guangming
authors.initials: G
authors.lastname: Lu
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Larson
mesh_terms: D016477:Artifacts; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007668:Kidney; D008099:Liver; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009038:Motion; D011860:Radiography, Abdominal; D012015:Reference Standards; D012119:Respiration; D013154:Spleen