Using Multi-model Diffusion Weighted Imaging to Study Acute Kidney Injury in Patients with Acute Pancreatitis

To explore the diagnostic value and severity of acute kidney injury (AKI) in patients with acute pancreatitis (AP) using intravoxel incoherent motion imaging (IVIM), diffusion tensor imaging (DTI), and diffusion kurtosis imaging (DKI).

224 AP patients, categorized into either the AKI group or the non-AKI group, were retrospectively analyzed in this study. MRI sequences included routine abdominal, IVIM, DTI, and DKI scans, and the main MRI parameters of kidney imaging and clinical characteristics were measured. The diagnostic performance of AKI was compared, and the relationships among these indices, glomerular filtration rate (eGFR), and AKI staging were analyzed. Finally, all parameters were analyzed by single and multi-parameter regression.

Compared with the non-AKI group, the fast apparent diffusion coefficient (ADC) value and perfusion fraction (Ff ADC) value of the renal medulla in the AKI group were significantly lower than those in the non-AKI group. The fractional anisotropy (FA) value in the renal cortex was significantly lower than that in the medulla and significantly lower than in the non-AKI group. Lastly, the renal medulla mean kurtosis (MK) value was also significantly lower in the AKI group compared to the non- AKI group and exhibited the best diagnostic value for AKI in AP patients. The renal medulla MK value positively correlated with AKI staging and negatively correlated with eGFR. The MK value was an independent risk factor for AKI, as evidenced by multi-parameter logistic regression analysis.

The measurement of renal DKI parameters is practical for diagnosing and predicting the severity of acute kidney injury in AP patients.