{ "abstract": "Background\n\nRenal fibrosis is the final common pathway of chronic kidney disease progression and a critical histological predictor of renal function decline and allograft failure. Routine clinical monitoring with estimated glomerular filtration rate (eGFR) and albuminuria is insensitive to fibrosis development. Renal biopsy is invasive and subject to sampling bias, which limits repeated assessment, thus necessitating noninvasive imaging biomarkers. Multiparametric magnetic resonance imaging (mpMRI) characterizes renal structure and function noninvasively. Individual MRI measures have been associated with fibrosis and with declining renal function. However, longitudinal validation against histology and measured glomerular filtration rate (mGFR) remains limited.Objective\n\nThis prospective longitudinal observational study aims to validate mpMRI against histological fibrosis assessed by kidney biopsy in kidney transplant recipients (KTRs), and compare the time-dependent trajectories of imaging and functional markers across living kidney donors (LKDs), KTRs, and healthy control (HC) cohorts.Methods\n\nThe planned sample includes 32 LKDs, 32 KTRs, and 32 HCs. Up to 40 KTRs may be recruited to account for attrition. Baseline assessments are performed before transplantation for LKDs and KTRs, and at enrollment for HCs, with follow-up assessments at 3, 12, and 24 months. mpMRI is performed at 3 tesla (3 T). The MRI protocol includes structural longitudinal relaxation time (T1)-weighted and T2-weighted imaging, T1 mapping, T2 mapping, transverse relaxation time (T2*) mapping, diffusion-weighted imaging, pseudocontinuous arterial spin labeling, non-contrast enhanced angiography, and phase-contrast measurement of renal artery flow. Glomerular filtration rate will be measured by [99mTc]Tc-diethylenetriaminepentaacetic acid (DTPA) clearance. A baseline allograft biopsy is taken during transplantation surgery, with protocol biopsies at 3, 12, and 24 months. Fibrosis is quantified using stereology. The primary outcome is the longitudinal association between the corticomedullary T1 difference and histologically determined renal fibrosis in KTRs across all 4 biopsy time points. Secondary analyses include longitudinal divergence of MRI and functional markers across cohorts, diagnostic performance for fibrosis, and predictive value for mGFR decline in KTRs and LKDs. Linear mixed models will be used to study longitudinal associations. Three additional MRI measures will be tested in a fixed sequence to control multiplicity. Receiver operating characteristic curve analysis will assess diagnostic performance.Results\n\nThe study was funded in October 2023. Recruitment for the multiparametric renal magnetic resonance imaging (MPRENAL) study commenced on October 29, 2024. As of March 2026, 42 participants were enrolled, and data collection is ongoing. Recruitment is anticipated to close in February 2027, with final study visits by March 2029. The primary results are expected to be published in 2030.Conclusions\n\nSuccessful completion of this study is expected to provide robust histological validation of mpMRI and establish its utility as a noninvasive tool for monitoring renal health.", "abstract_shown": true, "affiliations": [ "Department of Nephrology, Aalborg University Hospital, Mølleparkvej 4, Aalborg, Denmark, +45 97663700.", "The MR Research Centre, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.", "Department of Radiology, Aalborg University Hospital, Aalborg, Denmark.", "Department of Clinical Medicine, Aalborg University, Aalborg, Denmark.", "Department of Internal Medicine, Aalborg University Hospital, Hobro, Denmark.", "Department of Pathology, Aarhus University Hospital, Aarhus, Denmark.", "Core Center for Molecular Morphology, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.", "Department of Renal Medicine, Aarhus University Hospital, Aarhus, Denmark.", "Department of Nuclear Medicine, Aalborg University Hospital, Aalborg, Denmark." ], "article_type": "research article", "arxiv": null, "author_total": 11, "authors": [ { "affs": [ 0 ], "name": "Patrick Schjelderup", "orcid": "0009-0000-8549-4940" }, { "affs": [ 1 ], "name": "Steffen Ringgaard", "orcid": "0000-0001-5353-7379" }, { "affs": [ 2, 3 ], "name": "Jens Brøndum Frøkjær", "orcid": "0000-0001-8722-0070" }, { "affs": [ 4 ], "name": "Jens Dam Jensen", "orcid": "0009-0003-8148-3904" }, { "affs": [ 5 ], "name": "Søren Krag", "orcid": "0000-0003-1975-2766" }, { "affs": [ 5, 6 ], "name": "Jens Randel Nyengaard", "orcid": "0000-0002-8084-4646" }, { "affs": [ 1 ], "name": "Christoffer Laustsen", "orcid": "0000-0002-0317-2911" }, { "affs": [ 7 ], "name": "Niels Henrik Buus", "orcid": "0000-0001-7972-8181" }, { "affs": [ 8 ], "name": "Lars Jødal", "orcid": "0000-0002-6811-0172" }, { "affs": [ 7 ], "name": "Karin Skov", "orcid": "0000-0003-1559-4836" }, { "affs": [ 0 ], "name": "My Hanna Sofia Svensson", "orcid": "0009-0008-1255-2722" } ], "bibtex": "https://research.draconitic.com/paper/4rw06jg5mxekx.bib", "cited_by": 0, "doi": "10.2196/97152", "fulltext_url": "https://europepmc.org/articles/PMC13717433", "id": "4rw06jg5mxekx", "issns": [ "1929-0748" ], "landing_url": "https://europepmc.org/article/MED/42954158", "language": "eng", "licence": "CC-BY", "licence_label": "CC BY", "licence_source": "article", "licence_url": "https://creativecommons.org/licenses/by/4.0/", "metadata_licence": null, "native_subjects": [ [ "heading", "Clinical Information and Decision Making" ], [ "heading", "Digital Biomarkers and Digital Phenotyping" ], [ "heading", "Medical Imaging" ], [ "heading", "Nephrology/Renal Disorders" ], [ "heading", "Non-Randomized Study Protocols and Methods (Non-eHealth)" ], [ "heading", "Protocol" ], [ "lcc", "R" ], [ "lcc", "R858-859.7" ], [ "openalex", "2741|Advanced MRI Techniques and Applications" ] ], "openalex": "W7151002066", "pdf_url": "https://europepmc.org/articles/PMC13717433?pdf=render", "pmcid": "PMC13717433", "pmid": "42954158", "published": "2026-10-01", "publisher": "JMIR Publications Inc.", "ris": "https://research.draconitic.com/paper/4rw06jg5mxekx.ris", "sources": [ { "first_seen": "2026-11-01T00:20:36Z", "native_id": "MED:42954158", "source": "europepmc", "url": "https://europepmc.org/article/MED/42954158" }, { "first_seen": "2026-11-02T12:21:45Z", "native_id": "PMC13717433", "source": "pmc", "url": "https://doi.org/10.2196/97152" }, { "first_seen": "2026-11-05T14:21:13Z", "native_id": "1d4c17722c4f4eac971ae3a181d877a4", "source": "doaj", "url": "https://doi.org/10.2196/97152" } ], "subjects": [ { "field": "medicine", "origin": "openalex:2741|Advanced MRI Techniques and Applications", "subfield": "imaging" } ], "title": "Multiparametric Magnetic Resonance Imaging in a Prospective Cohort of Living Kidney Donors, Recipients, and Healthy Controls and Correlations With Markers of Renal Function, Fibrosis, and Aging (MPRENAL): Protocol for a Longitudinal Observational Study.", "title_text": "Multiparametric Magnetic Resonance Imaging in a Prospective Cohort of Living Kidney Donors, Recipients, and Healthy Controls and Correlations With Markers of Renal Function, Fibrosis, and Aging (MPRENAL): Protocol for a Longitudinal Observational Study.", "type": "peer-reviewed", "updated_at": "2026-11-06T14:20:42Z", "url": "https://research.draconitic.com/paper/4rw06jg5mxekx", "venue": "JMIR research protocols", "versions": [] }