Fig 1.
A General workflow to design and fabricate an anthropomorphic heterogeneous head phantom using 3D printing.
Table 1.
Constitutive properties and densities of the classified tissues at ~ 297 MHz.
Fig 2.
Medical data acquisition and segmentation.
A 3T MRI scan with 1.0x1.0x1.0mm3 resolution was segmented and divided into eight individual tissues. Each segmented tissue is listed with the corresponding tissue segmentation color within the tissue legend. The pictured MRI dataset and segmented tissues are shown in the mid axial, coronal and sagittal views. Table 1 lists the physiological tissues that were used to classify the tissues in the legend.
Fig 3.
Design and fabrication of physical phantom model.
Views of the shelled CAD files (A-C) which were developed in order to make volumetric cavities of the designated biological tissues that were segmented from a 3T MRI dataset. Views of the rapid prototype model (D) show the head phantom printed with stereolithography (SLA) resin. The physical head phantom dimensions are 30.5 cm tall, 25.4 cm long and 14.0 cm wide. The filling-ports are highlighted by arrows indicating the locations at which the fluids, resembling various tissue types, enter the phantom.
Fig 4.
Comparison of phantoms to in-vivo volunteer using the scattering parameters of an RF coil.
Fig 5.
Comparison of the experimentally mapped magnetic (B1) field distributions.
Congruent slices of each phantom in comparison with the human volunteer are shown in all planar views. The color bar ranges from 0 to 48.9μT per 500V. The maximum B1 intensity level is set to the highest pixel value among each of the phantoms and the volunteer.
Fig 6.
Comparison of phantom to in-vivo volunteer during an EPI stability scan at 7T MRI.
Table 2.
Stability parameters of phantoms and the volunteer for the EPI stability scans at 7T MRI.