The Role of MRI in the Clinical Management of Urologic and Nephrological Disorders

Abstract

MRI has become indispensable in the diagnosis and management of urologic and nephrological diseases. Technological advances over the past 2 decades—including multiparametric imaging, quantitative MRI, standardized reporting systems, deep learning–based reconstruction, and artificial intelligence (AI)—have expanded the role of MRI beyond anatomical assessment to tissue characterization, treatment planning, image-guided intervention, and therapeutic monitoring. This special issue of Magnetic Resonance in Medical Sciences comprises 7 review articles and 2 original investigations that summarize recent advances in MRI of the kidney, prostate, bladder, and upper urinary tract. Together, these contributions highlight recent advances in MRI and illustrate its evolving role as an integrated imaging platform that combines quantitative imaging, imaging biomarkers, AI, and image-guided therapy. This Editorial highlights the 7 review articles included in this special issue and provides an overview of recent advances in MRI for urologic and nephrological diseases.

Introduction

MRI has undergone remarkable technological advances over the past 2 decades and now plays an increasingly important role in the diagnosis and management of urologic and nephrological diseases. Owing to its excellent soft-tissue contrast and ability to provide both anatomical and functional information, MRI has expanded beyond a complementary imaging modality and is now widely incorporated into the evaluation of diseases involving the kidney, urinary tract, bladder, and prostate.

A major factor underlying this evolution has been the development of multiparametric MRI. By combining high-resolution anatomical imaging with functional techniques such as diffusion-weighted imaging, dynamic contrast-enhanced MRI, arterial spin labeling, blood oxygenation level–dependent imaging, and quantitative relaxation mapping, MRI provides complementary information on tissue cellularity, vascularity, perfusion, oxygenation, and pathological changes, including fibrosis. These advances have improved lesion characterization and facilitated the development of imaging biomarkers that may better reflect the biological characteristics of disease.

Standardized reporting systems, including the Prostate Imaging-Reporting and Data System (PI-RADS) and the Vesical Imaging-Reporting and Data System (VI-RADS), have contributed to more consistent image interpretation and communication among multidisciplinary teams. As clinical experience and supporting evidence continue to accumulate, these systems are expected to further facilitate the appropriate use of MRI in routine clinical practice and multicenter research. More recently, artificial intelligence (AI), particularly deep learning, has been increasingly explored for applications such as image reconstruction, lesion detection, segmentation, and workflow support. Although these technologies have shown promising results in many studies, further validation and clinical experience will be important to clarify their role in routine practice. MRI has also expanded its role in image-guided procedures, including MRI-targeted biopsy, MRI/ultrasound fusion–guided biopsy, and focal therapy.

The articles included in this special issue reflect these recent developments. The 7 review articles summarize current advances in renal tumor imaging, functional renal MRI, whole-body MRI with diffusion-weighted imaging with background body signal suppression (DWIBS), AI applications in prostate MRI, MRI-guided biopsy and focal therapy, bladder MRI with the VI-RADS, and MRI of the upper urinary tract.^1–7 Complementing these reviews, 2 original investigations provide new evidence regarding the clinical utility of deep learning reconstruction for accelerated prostate MRI and the histopathological basis of peritumoral enhancement in muscle-invasive bladder cancer.^8,9

Although each article focuses on a different aspect of MRI, together they illustrate the broadening role of MRI in contemporary urologic and nephrological practice. Advances in multiparametric imaging, quantitative MRI, standardized reporting systems, AI, and image-guided intervention have the potential to contribute to more individualized diagnosis and patient management. These developments also reflect the continuing evolution of MRI toward precision medicine.

In the following sections, we briefly introduce the 7 review articles and discuss how they collectively illustrate the evolving role of MRI in the diagnosis and management of urologic and nephrological diseases. The implications of the accompanying original investigations are considered in the concluding section.

Multiparametric MR Imaging of Renal Tumors: Histologic Subtype Differentiation and Diagnostic Frameworks¹ (To be published later)

Ikeda et al.¹ review the current role of multiparametric MRI in differentiating the major histologic subtypes of renal tumors. The authors summarize the complementary value of T2-weighted imaging, chemical-shift imaging, diffusion-weighted imaging, and dynamic contrast-enhanced MRI, together with structured diagnostic frameworks such as the Clear Cell Likelihood Score and the Bosniak Classification version 2019. This review provides a comprehensive overview of the current role of MRI in the characterization and clinical assessment of renal masses.

Multiparametric MR Imaging for Evaluating Renal Function and Microstructure²

Yamamoto et al.² summarize recent advances in quantitative renal MRI for evaluating renal function and tissue microstructure. The review describes emerging techniques, including T1 and T2 mapping, diffusion-weighted imaging, diffusion tensor imaging, arterial spin labeling, blood oxygenation level–dependent imaging, and intravoxel incoherent motion imaging, as non-invasive imaging biomarkers of renal physiology. These developments support the expanding role of MRI in the assessment and management of chronic kidney disease.

Detecting Distant Metastases in Prostate Cancer Using Whole-body MR Imaging Together with DWIBS (Diffusion-weighted Imaging with Background Body Signal Suppression)³

Nakanishi et al.³ review the technical principles and clinical applications of whole-body MRI with DWIBS for evaluating metastatic prostate cancer. The authors discuss its role in detecting skeletal metastases, monitoring treatment response, and complementing prostate-specific membrane antigen positron emission tomography. This review highlights the potential value of whole-body MRI as a comprehensive imaging tool for systemic evaluation of prostate cancer.

Integrating Artificial Intelligence into Prostate MR Imaging: Technical Foundations, Clinical Applications, and Workflow Implications⁴

Messina et al.⁴ provide a comprehensive overview of the rapidly expanding applications of AI in prostate MRI. The review covers deep learning–based image reconstruction, image quality assessment, automated segmentation and lesion detection, risk stratification, and clinical decision support while discussing current challenges in validation and implementation. This article discusses the potential role of AI in improving image quality, diagnostic consistency, and workflow efficiency in prostate MRI.

MR Imaging/Ultrasound Fusion–Guided Biopsy and Primary Focal Therapy for Localized Prostate Cancer⁵

Fujihara et al.⁵ review the current evidence supporting MRI/ultrasound fusion–guided biopsy and MRI-based focal therapy for localized prostate cancer. The authors summarize advances in MRI-targeted biopsy and contemporary focal treatment techniques while emphasizing individualized treatment strategies that preserve functional outcomes. This review illustrates the expanding role of MRI beyond diagnosis to image-guided intervention and personalized patient care.

Current Status and Future Perspective for Bladder Cancer MR Imaging and the Vesical Imaging-Reporting and Data System (VI-RADS) in Japan: Challenges and Solutions⁶

Takeuchi and Tamada⁶ review recent advances in bladder MRI with particular emphasis on the VI-RADS. The authors summarize current evidence supporting standardized MRI interpretation and discuss emerging imaging biomarkers, including peritumoral enhancement, tumor contact length, radiomics, and AI-assisted prediction models. This review discusses how standardized reporting and quantitative imaging may further contribute to the clinical application of bladder MRI.

MR Imaging of the Upper Urinary Tract: Techniques, Diagnostic Performance, and Imaging Biomarkers⁷

Nakamoto et al.⁷ summarize current MRI techniques for evaluating diseases of the upper urinary tract, including upper tract urothelial carcinoma. The review discusses optimized imaging protocols and emerging quantitative biomarkers such as apparent diffusion coefficient measurements and radiomics for improving lesion characterization and risk stratification. This article highlights the expanding clinical role of MRI in comprehensive assessment of upper urinary tract diseases.

Future Perspectives

The articles presented in this special issue provide an overview of recent advances in MRI for urologic and nephrological diseases. Collectively, they illustrate the continuing evolution of MRI, from a modality primarily used for anatomical depiction to broader applications in tissue characterization, quantitative assessment, image-guided intervention, and clinical decision support.

Several common themes emerge throughout this issue. Multiparametric MRI has become an important component of imaging evaluation by integrating structural and functional information. Quantitative MRI is increasingly providing imaging biomarkers with the potential to reflect tissue biology and disease activity. Standardized reporting systems such as PI-RADS and VI-RADS have contributed to improved reproducibility and facilitated multidisciplinary communication. At the same time, AI is expected to play an increasingly important role in image reconstruction, lesion detection, segmentation, quantitative analysis, and workflow support.

The 2 original investigations further reinforce these concepts by demonstrating the clinical value of AI-based image reconstruction for prostate MRI and the biological validation of an emerging MRI biomarker in bladder cancer. Together with the accompanying review articles, these studies illustrate how technological innovations are being translated into clinically applicable imaging strategies.

Importantly, these advances should not be regarded as independent technological developments but as complementary innovations supporting precision medicine. The continued integration of quantitative imaging, imaging biomarkers, AI, and image-guided intervention is expected to further expand the clinical applications of MRI and may contribute to more individualized diagnosis and patient management. Continued multicenter collaboration, technical standardization, and prospective validation will be essential for translating these innovations into routine clinical practice.

As MRI continues to integrate quantitative imaging, imaging biomarkers, AI, and image-guided intervention, it is evolving beyond a diagnostic modality into a comprehensive platform that supports precision medicine across the spectrum of urologic and nephrological diseases. We hope that this special issue will provide readers with valuable insights into current advances and stimulate further innovation in MRI research and clinical practice.