A Study to Compare How Well Gadoquatrane Works and Its Safety With an Already Available Contrast Agent for MRI in People With Known or Suspected Brain or Spinal Cord-related Problems

A Multicenter, Randomized, Prospective Double-blind, Cross-over Phase 3 Study to Evaluate the Efficacy and Safety of 0.04 mmol Gd/kg Body Weight of Gadoquatrane for MRI in Adults With Known or Suspected Pathology of the Central Nervous System (CNS), Compared to 0.1 mmol Gd/kg Approved Macrocyclic Gadolinium-based Contrast Agents (GBCAs)

Researchers are looking for a better way to help people with known or suspected brain or spinal cord-related problems scheduled for a "contrast-enhanced" Magnetic Resonance Imaging (MRI).

MRI is used by doctors to create detailed images of the inside of the body to identify health problems. Sometimes doctors need to inject a contrast agent into a patient's vein to perform a so called "contrast-enhanced" MRI (CE-MRI). Such CE-MRI examinations may support doctors to identify certain health problems or improve the evaluation.

The contrast agents commonly used in MRI are gadolinium-based contrast agents (GBCAs). GBCAs contain a "rare earth" element called gadolinium (Gd). Gadoquatrane is a new contrast agent under development with a lower amount of Gd needed per CE-MRI.

The main purpose of this study is to learn whether CE-MRI scans with gadoquatrane work better than MRI scans without the use of a contrast agent (GBCA). The researchers will compare the ability to detect brain and spinal cord-related problems in gadoquatrane-MRI scans to plain-MRI scans without the use of a contrast agent.

The participants will undergo 2 MRI scans, one with gadoquatrane and one with currently used GBCA. Both contrast agents will be injected into the vein.

Each participant will be in the study for between 6 and 42 days with up to 7 doctor visits.

At the start or during the study, the doctors and their study team will:

• take blood and urine samples
• do physical examinations
• check blood pressure and heart rate
• review the MRI scans obtained in the study and decide on the diagnosis
• ask the participants questions about how they are feeling and what adverse events they are having.

An adverse event is any medical problem that a participant has during a study. Doctors keep track of all adverse events, irrespective if they think it is related or not to the study treatments.

Inclusion Criteria:

• Participant must be >= 18 years of age inclusive, at the time of signing the informed consent form
• Participants with a clinical indication for a contrast-enhanced MRI (including MRA), with any approved standard of care macrocyclic GBCA with proven efficacy, safety and tolerability in clinical routine CE-MRI/MRA (gadobutrol, gadoterate meglumine/ gadoteric acid or gadoteridol) that is used at the site for the indication, for a known or suspected CNS pathology
• Participants who can undergo study-related procedures, including 2 contrast-enhanced MRI examinations (one with gadoquatrane and one with a comparator macrocyclic GBCA), as per participant and Investigator's judgement
• Contraceptive use by female participants should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies. A female participant is eligible to participate if she is not pregnant or breastfeeding, and one of the following conditions applies: Is a woman of nonchildbearing potential (WONCBP) OR Is a woman of childbearing potential (WOCBP) and using an acceptable contraceptive method during the study intervention period (at a minimum of 24 hours after the last dose of study intervention)

Exclusion Criteria:

• Considered clinically unstable or has a concurrent/concomitant condition that may significantly alter image comparability between the 2 study MRIs or between study parameters (e.g. safety, pharmacokinetics [PK] parameters) or would not allow participation for the full planned study period, in the judgement of the investigator
• Participants presenting with severe renal insufficiency, defined as an estimated glomerular filtration rate (eGFR) < 30 mL/min/1.73 m^2, derived from a serum or plasma creatinine sample obtained within 48 hours prior to the first contrast agent injection in the study
• Participants with acute kidney injury (i.e., acute renal failure), regardless of eGFR
• History of moderate to severe allergic-like reaction to any GBCA
• Bronchial asthma considered unstable or who have had recent modification to their medical therapy
• Receipt of any contrast agent < 72 h prior to the study MRIs or planned to receive any contrast agent during the trial until 24 h +/- 4 h after the second study MRI
• Planned or expected interventional diagnostic or therapeutic procedure (e.g. biopsy or surgery in the region of interest) or change in treatment (e.g. start of chemotherapy or antiangiogenic therapy, significant change in corticosteroids dose) that may significantly alter image comparability between the 2 MRIs or other study parameters (i.e. safety/adverse events (AEs) [e.g. confounding AEs or safety events due to surgery or chemotherapy], PK parameters), from the first study MRI up to 24 h after the second study MRI
• Has received any investigational product within 30 days, or within 5 times half-life of the investigational product, whatever is shorter, prior to or concurrent with this study
• Contraindications to the administration of macrocyclic GBCAs (depending on local product label), or history of adverse reaction to gadoquatrane
• Any contraindication to MRI examinations based on institution policy and investigator's clinical judgement (e.g. some metallic implants or active implants)