Depending on the type of magnetic substance, the primary effect may be on either T₁- or T₂-weighted imaging, and contrast agents are accordingly classified as T₁ or T₂ contrast agents.Research on contrast agents is highly active internationally, with multiple types already in production and clinical use.Currently, seven gadolinium-based contrast agents have been approved for market use by the National Medical Products Administration (NMPA) in China.

To evaluate the relaxivity of gadolinium-based MRI contrast agents and perform T1-weighted imaging of the contrast agent samples.

With the advancement of nanotechnology, biologically functionalized superparamagnetic nanoparticles—conjugated with various biomolecules such as nucleic acids, small molecules, peptides, or antibodies—have been widely developed for applications in bio-enrichment and molecular recognition.

Magnetic resonance (MR) is a powerful imaging technique that has been widely applied in the diagnosis of various diseases due to its non-ionizing nature and high resolution, particularly for soft tissue imaging.

Relaxivity is one of the key performance indicators of MRI contrast agents.

Contrast agents are substances that indirectly alter tissue signal intensity through internal and external relaxation effects as well as susceptibility effects, thereby enhancing the contrast between different tissues or organs in imaging.

Magnetic resonance imaging (MRI) is now widely used in medical diagnostics due to its non-ionizing nature, making it a safe imaging modality.It offers high flexibility through multi-planar imaging capabilities and supports various contrast mechanisms such as proton density, relaxation, and weighted imaging, along with multiparametric features.As a result, MRI has become one of the most powerful tools in modern clinical diagnosis.However, clinical studies have found that the relaxation times of certain different tissues or tumor types may overlap, making accurate diagnosis challenging in some cases.

Magnetic resonance imaging (MRI) is widely used in clinical practice due to its non-invasive nature, rapid acquisition, high resolution, and excellent contrast.In particular, for tumor diagnosis, MRI has become an indispensable tool in the early detection of primary tumors and metastases.By capturing structural and functional images based on the physical property differences between pathological and normal tissues, MRI provides critical information for accurate and early diagnosis.