Myelin protons have ultrashort-lived MR signals and are not accessible by clinical MRI. Such signals were probed herein using ultrashort echo time imaging (UTE) and inversion-recovery UTE (IR-UTE) with bi-component analysis in native and deuterated ovine brain specimens. UTE detected a fraction of ultrashort T2 components (STC) of < 4% in native specimens, and up to ~54% in deuterated specimens. Choice of inversion time in IR-UTE significantly affected such bi-component signal decay behavior in native samples in heavily deuterated samples. These results support the application of UTE and IR-UTE in quantitative myelin imaging.