Keywords:
MRI, Contrast agents, Liver, MR physics, MR, Contrast agent-intravenous, Quality assurance, Retrospective, Not applicable, Performed at one institution
Authors:
A. Pratesi1, S. Covizzoli2, S. Chiti2, D. Ermini2; 1Siena/IT, 2Florence/IT
DOI:
10.26044/ecr2020/C-06298
Methods and materials
We observed MR liver exams with Gd-EOB-DTPA acquired with a 1.5T scanner (gradients 45 mT/m, slew rate 200 mT/m/ms) of 146 patients, 84 with sequential K-Space and 62 with centric K-Space. The study was retrospective for “sequential patients” and perspective for “centric patients”. We used a 3D Rapid acquisition GRE FID imaging sequence (Figure 1)(Figure 2), acquired with a 18 channels Body coil in combination with a 32 channels Spine coil. For sequential K-Space filling and an acquisition time of 21 seconds, the time to center is 10.6 seconds (we started to acquire from 3D K-Space periphery, then we moved on to acquire the center, then the periphery again) (Figure 3), while for centric K-Space filling and the same acquisition time, the time to center is 1.3 seconds (we started to acquire 3D K-Space from the center, then we moved on to the periphery progressively) (Figure 4). After bolus contrast injection, for all the observed studies the delay for arterial scan phase was fixed at 35 seconds. Injection rate was fixed at 0.8 ml/s. Discarded patients are considered “non-collaborative” when motion artifacts (that manifests itself like hyper and hypo-intense lines around impregnated organs and abdominal wall that propagate out of human anatomy) are present in 2 dynamic series or more (for example, arterial and venous phase or arterial and pre-bolus injection phase).