Analysis of the clinical diagnostic capabilities of kidney imaging biomarkers based on diffusion-weighted imaging and ASL-perfusion data

Abstract

Acute kidney failure is a polyetiological disease that is often occurs in patients, which requires a rapid therapeutic response to avoid progression of the condition. Magnetic resonance imaging of the kidneys (MRI) improves the understanding and assessment of pathological processes, supplementing the mandatory diagnostic minimum information in the study of kidney pathology.Objective. To evaluate the clinical diagnostic capabilities of kidney imaging biomarkers using diffusion-weighted imaging (DWI) and ASL-perfusion data for intensive care unit patients.Materials and methods. At the first Clinical Hospital in Smolensk 54 patients were examined who were inpatient treatment and in the intensive care unit. All patients underwent ultrasound examination of the kidneys with assessment of blood flow in the main kidney vessels, MRI of the kidneys, with DWI of the kidney parenchyma and ASL-perfusion included in the study protocol. MRI was carried with assessed b-factor 800 and was drawn apparent diffusion coefficient (ADC) maps. When carried ASL perfusion, the field of view covered the area of the parenchyma of both kidneys. The reference method was glomerular filtration rate for all of the patients. The control group was represented by healthy people (n=59). Consent to participate in the study was obtained from patients or their legal representatives. All stages of the study comply with the normative and regulatory documentation of Ministry of Health ща the Russian Federation.Results. It was concluded that there is a significant difference in ADC for prerenal causes and in ASL for renal causes. In 9 (16.7 %) patients, kidney ADC was 1.5±0.3 mm2/sec, ASL – perfusion – ≤ 250 ml/100g/min, compared with the control group. In this group, negative dynamics were observed within a week, тnegative laboratory dynamics correlates with radiation-based kidney biomarkers (r=0,965).Conclusion. The criteria of DWI and ASL-perfusion allow us to suspect or confirm the cause of acute kidney failure. A high correlation has been established between radiation biomarkers and laboratory criteria of functional damages (r=0.998), direct correlation between imaging biomarkers and organic kidney disease (r=0,901). These biomarkers make it possible to predict the first stage of acute kidney failure (AUROC 0,995, DI 0,867–0,999).