A Study About How Blood Cell Growth Patterns Relate to Heart Health After Treatment for Hodgkin Lymphoma

Inclusion Criteria: * Patient must be \>= 7 years of age at the time of enrollment (age to perform an MRI without sedation). * History of pathologically confirmed classical Hodgkin Lymphoma (cHL) initially diagnosed when the patient was \>= 2 and \< 22 years of age. * As part of frontline therapy for cHL, the patient must have received a cumulative doxorubicin equivalent anthracycline dose of ≥ 200 mg/m\^2 as estimated in doxorubicin isotoxic equivalents dose conversion calculation. * Note: History of COG therapeutic trial participation is not required. Institutional records (e.g., clinic note, treatment summary, chemotherapy roadmap) can be used as reference documentation of receipt of anthracycline dose. * All systemic cancer treatment must have been completed ≥ 2 years prior to study enrollment. * Not known to have had a primary event (relapse/second malignancy/death). * Note: Subjects treated at another institution are eligible if they are now being followed at the current COG institution, if the study procedures can be performed and the data accessible by a COG institution where the study is open. * Patient must have access to cardiac MRI at the enrolling institution and must be able to complete cardiac MRI without sedation. Exclusion Criteria: * Medical contraindication to undergoing a non-contrast cardiac MRI. * Patients with nodular lymphocyte-predominant HL. * Received cancer therapy in addition to that for primary Hodgkin Disease (e.g., for disease progress…