PROBLEM TO BE SOLVED: To provide a diagnosis method of clinical symptoms characterized by a detection of selectin and an undesirable and/or unusual selectin expression.SOLUTION: The invention relates to a selectin targeting imaging agent which contains at least one fucoidan portion associated with at least one detectable potion, and to a method and a kit using the imaging agent, which are used for diagnosis of clinical symptoms, such as thrombosis, myocardial ischemia/reperfusion injury, a stroke and an ischemia brain trauma, neurodegenerative disorder, tumor metastasis and tumor growth, and rheumatoid arthritis. The imaging agent is detectable by ultrasonography, Magnetic Resonance Imaging (MRI), Positron Emission Tomography (PET), Single Photon Emission Computed Tomography (SPECT), fluorescence spectroscopy, computed tomography, X-ray radiography, or any combination thereof.
