Through the utilization of fMRI and DUS we aim to illustrate the physiological change a kidney graft undergoes during a transplantation trajectory from donor to recipient. Secondarily, we intend to establish a baseline reference for normal…
Source
Brief title
Condition
- Other condition
- Renal disorders (excl nephropathies)
- Renal and urinary tract therapeutic procedures
Synonym
Health condition
Nier Transplantatie
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
Functional MRI (fMRI)
(P) ASL: *% Renal Blood Flow (ml/min/100g)
DWI-IVIM: Molecular diffusion (Dslow, mm2/s), Microperfusion (Dfast, mm2/s),
Fraction of microperfusion (ffast, %), Apparent diffusion coefficient (ADC,
mm2/s)
DKI: Diffusional Kurtosis (DK), Diffusion coefficient (mm2/s)
DTI: Fractional Anisotropy (FA), Trace (tr), Mean diffusivity (MD, mm2/s)
BOLD: Relaxation rate (R2*, s-1)
TMRE: shear wave speed (m/s), viscosity (rad)
Doppler Ultrasound (DUS)
*% Resistive Index (RI)
Grayscale Median (GSM)
Shear wave elastography (SWE, kPa)
Microbubble (CEUS) Contrast Enhanced Ultrasound (Peak, TP, AUC, MTT)
Corticomedullary Differentiation (CMD)
Volume (ml)
Secondary outcome
The measured and/or estimated glomerular filtration rate.
Kidney biopsy histology (when available/clinically indicated).
Prognostic/Follow up parameters (Duration of admission, postoperative
complications, surgical reintervention, delayed graft function (DGF), graft
failure, postoperative dialysis, renal function at 1 week, 3 and 6 months and 1
year post-transplant, patient survival).
Background summary
Safe and accurate estimation of kidney allograft function in the early
postoperative period is of vital importance. In this study we utilize fMRI and
DUS imaging in both the donor and recipient to better understand the effect of
transplantation on a kidney graft and to distinguish normal post-transplant
changes from allograft dysfunction. Currently, kidney biopsy is considered the
gold standard for the assessment of kidney allograft pathology. However, its
invasive nature and associated risk of bleeding and infective complications
make it a suboptimal instrument. Biopsies are also prone to sampling errors.
fMRI is a non-invasive technique well suited for the assessment of kidney
transplants. It has the potential to become a powerful tool in diagnostic
research and may even influence postoperative decision making. However, these
functional sequences have not yet been validated in larger and more homogeneous
cohorts. The use of reproducible and representative quantitative parameters
should be further explored. Larger cohorts, in addition to providing
quantitative information, would also allow for multivariate analysis. By
combining data from different fMRI sequences with patient and donor
characteristics, we could potentially increase the power of the clinical
decision support models. In addition, the quantitative information obtained
from the different fMRI sequences can be used to train computer algorithms to
recognize variants of normally functioning kidneys and distinguish them from
real kidney graft pathology. In the same perspective, renal duplex
ultrasonography can complement fMRI and provide several parameters to
understand a healthy kidney. Ultrasound is characterized as non-invasive,
non-nephrotoxic, less expensive, more readily available, and more applicable
than other imaging methods. However, this modality is not part of routine pre-
and post-transplant renal assessment. To diagnose morphological changes after
transplantation, the collection of serial duplex data is essential to diagnose
early complications.
Study objective
Through the utilization of fMRI and DUS we aim to illustrate the physiological
change a kidney graft undergoes during a transplantation trajectory from donor
to recipient. Secondarily, we intend to establish a baseline reference for
normal physiological graft changes allowing for the recognition of graft
dysfunction at an early stage, thus aiding diagnostics.
Study design
A total of 40 living kidney donors and associated recipients will be
prospectively included. The fMRI protocol includes anatomical (T1 and T2
weighted) sequences, combined with ASL, IVIM, DTI, TMRE and BOLD sequences.
Quantitative imaging parameters such as RBF, intravoxel perfusion and diffusion
values, fractional anisotropy, mechanical properties and R2* values will be
calculated from these different sequences. The renal DUS protocol will consist
of the following parameters: renal size, renal artery and vein flow, GSM, RI,
PSV, EDV,CMD. Both living donor and recipient will be studied with renal DUS
before and after transplantation (baseline and follow-up). A subset of 5 living
kidney donors will be scanned with fMRI twice (prior to donation) to determine
the test-retest variability of the functional readings. Kidney fMRI parameters
before donation (2-4 weeks) and after transplantation (1 week and 3-4 months)
will be compared and correlated with mGFR and biopsy results (if
available/clinically indicated). Furthermore, the association between the mGFR
and/or eGFR (creatinine from 24-hour urine) 3-4 months after transplantation,
and the biopsy results of the standard kidney biopsy (taken during
transplantation), and the quantitative information from the fMRI images will be
investigated.
Study burden and risks
Benefits: Current methods to diagnose different causes of early graft
dysfunction such as allograft rejection, acute kidney injury (AKI), perfusion
impairment/ischemia, CNI toxicity, and technical problems related to the
surgical procedure, like vascular stenosis/thrombosis, urinary tract
obstructions/leaks, and urinomas/hematomas, thrombotic microangiopathy (TMA)
are limited. However, early detection is crucial to prevent damage to the
kidney graft and optimize (therapeutic) intervention. Therefore the study of,
and possible subsequent introduction of, a new clinically applicable
non-invasive diagnostic tool (fMRI) to accurately diagnose different types of
early kidney allograft dysfunction could have major implications for the care
of kidney transplant recipients. Major benefits of fMRI include its
non-invasive nature, no exposure to ionizing radiation or contrast agents, and
low burden for patients relative to other diagnostic methods.
Therefore, this study could have important implications for the care of renal
transplant recipients due to the introduction of a new clinically applicable
non-invasive diagnostic tool (fMRI) to accurately diagnose different types of
early renal transplant dysfunction. The main advantages of fMRI include its
non-invasive nature, no exposure to ionizing radiation or contrast agents, and
low patient burden compared to other diagnostic methods.
Risks: The overall risks faced by participants in this study are limited.
First, no experimental products are used. Doppler ultrasound evaluation of the
transplantated kidney is already standard care as per UMCG protocol. The only
"extra" study procedures that participants will be subjected to are fMRI and
'contrast enhanced echography'. The risks associated with fMRI and 'contrast
enhanced echography' are neglible when UMCG protocols are followed. Second,
participation in this trial does not interfere in any way with the standard
care participants would otherwise receive surrounding their transplantation.
Thus a patient can withdraw from this study at any time without consequence.
Hanzeplein 1
Groningen 9713 GZ
NL
Hanzeplein 1
Groningen 9713 GZ
NL
Listed location countries
Age
Inclusion criteria
Be part of a matched pair of living kidney donors and recipients;
Transplantation and follow-up consult performed at UMCG;
18-75 years old.
Exclusion criteria
Subjects aged <18 years;
Subjects unable or not willing to provide informed consent;
Subjects with a contraindication for fMRI (e.g. claustrophobia) and/or a DUS.
Design
Recruitment
Medical products/devices used
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
Register | ID |
---|---|
CCMO | NL79891.042.21 |