Multimodal Ultrasound in DBD Kidneys for Predicting Early Postoperative Renal Insufficiency Risk

Inclusion Criteria: * Recipient Study Participants Age ≥18 years; Underwent allogeneic kidney transplantation at this hospital; Signed informed consent form. Donor Study Participants Brain-deceased organ donors; Completed organ donation at the First Affiliated Hospital of Shandong First Medical University (Qianfoshan Hospital of Shandong Province); Brain death criteria: Deep coma (with clear etiology and exclusion of reversible causes); Absence of brainstem reflexes; No spontaneous respiration; Confirmed by at least two confirmatory tests (SLSEP, EEG, TCD), with re-evaluation 12 hours after the initial determination. Standard Criteria Donor (SCD): * Age 10-39 years; * Cause of death unrelated to cerebrovascular disease; * Serum creatinine \<133 μmol/L; * No history of hypertension. Expanded Criteria Donor (ECD): * Age \>60 years; OR ② Age 50-59 years with two of the following three criteria: * Cause of death related to cerebrovascular disease; * Serum creatinine \<133 μmol/L; * History of hypertension. Signed informed consent form. Exclusion Criteria: * Recipient Study Participants Patients with multiple kidney transplants; Patients with follow-up duration less than 1 year; Patients experiencing irreversible loss of graft function due to postoperative complications (e.g., rejection, thrombosis, anastomotic stenosis, infection). Donor Study Participants Severe primary renal diseases (e.g., hypertensive nephropathy, diabetic nephrop…