PURPOSE: Realizing the challenges and opportunities of effective transverse relaxation rate (R2 *) mapping at high and ultrahigh fields, this work examines magnetic field strength (B0 ) dependence and segmental artifact distribution of myocardial R2 * at 1.5, 3.0, and 7.0 T. METHODS: Healthy subjects were considered. Three short-axis views of the left ventricle were examined. R2 * was calculated for 16 standard myocardial segments. Global and mid-septum R2 * were determined. For each segment, an artifactual factor was estimated as the deviation of segmental from global R2 * value. RESULTS: The global artifactual factor was significantly enlarged at 7.0 T versus 1.5 T (P = 0.010) but not versus 3.0 T. At 7.0 T, the most severe susceptibility artifacts were detected in the inferior lateral wall. The mid-septum showed minor artifactual factors at 7.0 T, similar to those at 1.5 and 3.0 T. Mean R2 * increased linearly with the field strength, with larger changes for global heart R2 * values. CONCLUSION: At 7.0 T, segmental heart R2 * analysis is challenging due to macroscopic susceptibility artifacts induced by the heart-lung interface and the posterior vein. Myocardial R2 * depends linearly on the magnetic field strength. The increased R2 * sensitivity at 7.0 T might offer means for susceptibility-weighted and oxygenation level-dependent MR imaging of the myocardium.
PURPOSE: Realizing the challenges and opportunities of effective transverse relaxation rate (R2 *) mapping at high and ultrahigh fields, this work examines magnetic field strength (B0 ) dependence and segmental artifact distribution of myocardial R2 * at 1.5, 3.0, and 7.0 T. METHODS: Healthy subjects were considered. Three short-axis views of the left ventricle were examined. R2 * was calculated for 16 standard myocardial segments. Global and mid-septum R2 * were determined. For each segment, an artifactual factor was estimated as the deviation of segmental from global R2 * value. RESULTS: The global artifactual factor was significantly enlarged at 7.0 T versus 1.5 T (P = 0.010) but not versus 3.0 T. At 7.0 T, the most severe susceptibility artifacts were detected in the inferior lateral wall. The mid-septum showed minor artifactual factors at 7.0 T, similar to those at 1.5 and 3.0 T. Mean R2 * increased linearly with the field strength, with larger changes for global heart R2 * values. CONCLUSION: At 7.0 T, segmental heart R2 * analysis is challenging due to macroscopic susceptibility artifacts induced by the heart-lung interface and the posterior vein. Myocardial R2 * depends linearly on the magnetic field strength. The increased R2 * sensitivity at 7.0 T might offer means for susceptibility-weighted and oxygenation level-dependent MR imaging of the myocardium.
Authors: Jaume Coll-Font; Shi Chen; Robert Eder; Yiling Fang; Qiao Joyce Han; Maaike van den Boomen; David E Sosnovik; Choukri Mekkaoui; Christopher T Nguyen Journal: Magn Reson Med Date: 2021-08-13 Impact factor: 4.668
Authors: Petr Dusek; Elena Maria Tovar Martinez; Vince Istvan Madai; Robert Jech; Jan Sobesky; Friedemann Paul; Thoralf Niendorf; Jens Wuerfel; Susanne A Schneider Journal: Mov Disord Clin Pract Date: 2014-10-23
Authors: Pandji Triadyaksa; Niek H J Prakken; Jelle Overbosch; Robin B Peters; J Martijn van Swieten; Matthijs Oudkerk; Paul E Sijens Journal: MAGMA Date: 2016-12-16 Impact factor: 2.310
Authors: Anders Bruun Mathiasen; Abbas Ali Qayyum; Erik Jørgensen; Steffen Helqvist; Annette Ekblond; Michael Ng; Kishore Bhakoo; Jens Kastrup Journal: Stem Cells Int Date: 2019-11-14 Impact factor: 5.443