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 nephropathy, renal tumors); Cases with unavailable ultrasound imaging data: Excessive respiratory motion in donors; Obesity or other factors affecting imaging quality. Individuals with allergic predisposition.