Guangwei Du, et al. - In view of the challenges posed by the technical complexity and inconsistent results of newer magnetic resonance imaging (MRI) techniques that have shown promise in capturing early Parkinson disease (PD)-related changes in the substantia nigra pars compacta (SNc), the key pathological loci, researchers used a novel yet simple MRI contrast, the T1w/T2w ratio, to assess 76 PD patients and 70 controls. A higher T1w/T2w ratio was noted in PD patients vs controls in both the right (cluster size = 164mm3) and left (cluster size = 213mm3) midbrain that was located ventrolateral to the red nucleus and corresponded to the SNc. These findings support the efficacy of T1w/T2w ratio in detecting PD-related changes in the SNc and can be used as a novel, frugal in vivo biomarker for PD, especially for patients in the early stage, with high translational value for clinical practice and research.