The orbitofrontal cortex (OFC) area plays a critical role in human brain functions. However, susceptibility differences between paranasal sinuses and nasal cavity tissues often cause local field variations in the OFC during MRI, resulting in image distortions and signal loss. In this paper, we introduce a subject-friendly neck passive shim solution aimed at enhancing field homogeneity in the brain, specifically in the OFC region. Utilizing 3D gradient-echo pulse sequences, main magnetic field (B0) maps of four subjects’ brains were acquired at 4T MRI. Subsequently, these maps were decomposed into spherical harmonic coefficients and averaged. Optimal positions for placing shim elements on a semi-cylindrical surface, positioned slightly above the neck and below the chin, were computed. The findings indicate a substantial enhancement in B0 homogeneity, particularly within the OFC region, through the integration of this semi-cylindrical passive shim system in conjunction with first and second-order active shimming.