Fibrogenesis is a feature of idiopathic pulmonary fibrosis (IPF) that leads to the increased deposition and cross-linking of collagen. There remains a demand for non-invasive imaging of fibrogenesis in patients with suspected IPF to deliver earlier diagnoses and monitor treatment response. One universal feature of fibrogenesis is the oxidation of lysines on collagen to form allysine, which is a fundamental component for the cross-linking of collagen. We developed GdOA, a Gd-based MR probe that targets allysine as a marker for active fibrogenesis. We demonstrate that GdOA MR signal enhancement correlates with extent of disease and is sensitive to therapeutic response.