This technology includes a peptide containing alternating Alanine and Lys(DOTA-Gd) residues can be used to increase the MRI relaxivity of a peptide. The low molecular weight construct can be appended to proteins, antibodies and peptides to increase MRI signals. This approach offers advantages over previous dendrimeric constructs. The increased MRI signal may allow effective neuronal tracing of peptides that when misfolded and transported from the gut to the brain may lead to inflammation and serious diseases including Alzheimer’s (A-beta), Parkinson’s Disease, Lewey Body Dementia, and Multiple Systems atrophy (alpha synuclein), Creutzfeld-Jakob disease, and Amyotrophic lateral sclerosis.