This is an operationally combined Phase 2/3 study, which will be conducted and evaluated in 2 distinct parts:
* Phase 2: Prospective, adaptive, multicenter, non-randomized, single-blind, dose-finding, including participants with known or highly suspected lesions of the CNS. The aim of the Phase 2 part is to identify an optimized dose of mangaciclanol for the Phase 3 part of the study. * Phase 3: Prospective, multicenter, randomized, controlled, single-blind, cross-over, including participants with known or highly suspected lesions of the CNS or body. The aim of the Phase 3 part is to further evaluate the efficacy and safety of mangaciclanol-enhanced MRI for the detection and characterization of lesions of the CNS or body.
The investigational medicinal products (IMPs) used during the trial are mangaciclanol and gadobutrol (comparator IMP).
Primary and key secondary efficacy analyses will be based on independent central blinded image evaluation (BIE), and Phase 2 data will be analyzed prior to commencement of Phase 3.
The participant is of legal majority age, as defined by local laws and regulations at the time of signing the ICF.
The participant is able and willing to comply with study procedures as described in the protocol.
The participant has read, understood, signed and dated the ICF prior to any study procedures.
Phases 2 and 3 CNS: Participants presenting with known or highly suspected enhancing CNS lesions referred as part of standard care for contrast-enhancing MRI of the CNS. The suspicion may be based on a previous imaging procedure such as computed tomography (CT), positron emission tomography (PET)/CT or MRI performed within 12 months prior to ICF signature.
The participant has previously enrolled in this mangaciclanol study, including participation in an earlier phase or cohort.
The participant has a contraindication to MRI examination, such as the presence of a cardiac pacemaker or other electronic devices, presence of ferromagnetic metal foreign bodies in vulnerable positions or within positions that would affect the imaged field of view, presence of certain tattoos that may raise a safety concern for MRI, participant suffering from severe claustrophobia which is not manageable with standard sedation, or participant working as a machinist, welder or metal worker (unless the participant will undergo thorough screening by radiology personnel to rule out the presence of metallic foreign bodies, especially in or near the eyes).
Participant with severe cardiovascular disease (e.g., known long QT syndrome including QTc prolongation based on screening ECG, acute myocardial infarction within the past 14 days, unstable angina, congestive heart failure class III/IV by New York Heart Association classification, or acute stroke within the past 48 hours).
(Phase 2 only) Participant with an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 calculated using the Chronic Kidney Disease Epidemiology Collaboration equation (CKD-EPI) within 14 days prior to the first IMP administration.