We introduce an optimized design for a three-magnet array unilateral magnetic resonance (MR) device. The sensitive spot is 0.5 cm³, and begins roughly 0.5 cm from the magnet surface with a field variation of less than 1.5% of the B₀ resonant frequency. 3D simulation was used in conjunction with a trust-region optimization method to determine the optimal magnet geometry to achieve a large sensitive spot. A standard surface coil was used to excite and detect the MR signal from the sensitive spot. The array has dimensions of 8.4 × 7.4 × 4.1 cm and a mass of 0.74 kg. The surface of the magnets are shielded with a thin layer of copper tape to avoid acoustic ringing. Attenuation of the B₁-field due to eddy currents in the copper sheet was reduced by displacing the coil from the surface, at the cost of working distance. The quality factor and B₁-field attenuation due to eddy currents are explored experimentally by incrementally displacing the coil from the magnet surface. A minor reduction in working distance increases the sensitivity of the measurement. To assess device performance, T₁, T₂, T₁–T₂, and diffusion measurements were undertaken with a cod liver oil phantom.

我们介绍了三磁体阵列单边磁共振 (MR) 设备的优化设计。敏感点为 0.5 cm ³，从距磁体表面大约 0.5 cm 处开始，磁场变化小于 B ₀共振频率的1.5% 。3D 模拟与信任区域优化方法结合使用，以确定最佳磁体几何形状，以实现大敏感点。标准表面线圈用于激发和检测来自敏感点的 MR 信号。该阵列的尺寸为 8.4 × 7.4 × 4.1 cm，质量为 0.74 kg。磁体表面用一层薄薄的铜带屏蔽，以避免产生声响。B _{1 的}衰减通过将线圈从表面移开，以工作距离为代价，减少了由于铜片中的涡流引起的磁场。通过将线圈从磁体表面逐渐位移来实验性地探索由于涡流引起的品质因数和 B _{1 场}衰减。工作距离的微小减少会增加测量的灵敏度。为了评估设备性能，使用鱼肝油模型进行了T ₁、T ₂、T ₁ – T ₂和扩散测量。