Functional MRI Can Detect Diabetic Nephropathy Earlier

As the prevalence of diabetes continues to increase, so too does the rate of diabetic nephropathy, also known as diabetic kidney disease. 

In clinical practice, diabetic nephropathy is diagnosed based only on albuminuria, with kidney biopsy being the gold standard for a definitive diagnosis. However, making such a diagnosis has become significantly more challenging. 

That’s because the use of new therapeutic agents, such as SGLT2 inhibitors and GLP-1 receptor agonists, can cause normoalbuminuric diabetic kidney disease (NADKD), a condition where renal dysfunction progresses without the presence of albuminuria. 

“In this context, there is a growing need to evaluate diabetic nephropathy using multiparametric approaches,” said Akira Yamamoto, MD, PhD, associate professor at Kawasaki Medical School in Kurashiki, Okayama, Japan.

Helping to answer this need is functional MRI.

Speaking at a Wednesday session, Dr. Yamamoto discussed his recent study that evaluated renal function using multiparametric functional MRI. 

“Our goal was to assess whether various functional MRI parameters can reflect renal histological changes and allow for non-invasive risk stratification according to the KDIGO classification,” Dr. Yamamoto said.

KDIGO (Kidney Disease: Improving Global Outcomes) is the global nonprofit organization developing and implementing evidence-based clinical practice guidelines in kidney disease.

For the study, patients were divided into five KDIGO risk groups (lowest to highest) based on Estimated Glomerular Filtration Rate (eGFR) and albuminuria. The prospective, non-contrast study included 122 subjects: 23 healthy volunteers and 99 outpatients diagnosed with diabetic nephropathy. 

MRI measurements from both the renal cortex and renal medulla were obtained from each subject. MRI parameters included T1 and T2 values, blood oxygenation level-dependent (BOLD) imaging, intravoxel incoherent motion (IVIM) imaging, arterial spin labeling (ASL), and corticomedullary differentiation (CDM).

Group comparisons and post hoc analyses were performed, and findings were interpreted taking into consideration known diabetic nephropathy pathology.

Functional MRI as a Potential Biomarker

Researchers observed significant differences between the healthy and low-risk groups in the T2 values of the cortex and CMD on optimal T1. This suggests that the established parameters capture the increased cortical water content caused by glomerular hyperfiltration in the early phase of diabetic nephropathy.

According to Dr. Yamamoto, this marks a significant improvement over the current clinical practice of basing a diagnosis solely on albuminuria. 

“Diabetic nephropathy is a multifactorial and complex disease process,” Dr. Yamamoto explained. “By assessing multiple indicators, functional MRI has the potential to serve as a biomarker capable of estimating histopathological alterations without the need for invasive procedures like renal biopsy.”   

The approach could also enable earlier therapeutic intervention and improve the prognosis of patients with diabetic nephropathy. 

A New Frontier in Radiological Diagnosis 

While Dr. Yamamoto’s study clearly demonstrates functional MRI’s usefulness in detecting diabetic nephropathy earlier, more work still needs to be done. For example, conducting multicenter studies will increase the number of cases, making it possible to enhance the reliability and robustness of the data and, ultimately, promote the clinical implementation of this novel approach.

“The introduction of functional imaging techniques into the clinical evaluation of the kidneys will represent a new frontier in radiological diagnosis and a major advancement in the field of radiology as a whole,” Dr. Yamamoto concluded.

Access the presentation, “Evaluation of Renal Histological Changes with the Progression of Diabetic Nephropathy Using Functional MRI Parameters,” (W6-SSGU05-2) on demand at RSNA.org/MeetingCentral.