Multiparametric Magnetic Resonance Imaging (MRI) in Medullary Sponge Kidney (MICARI)

Background : Medullary sponge kidney disease is a congenital disorder caracterised by tubular ectasia and cystic dilatation of the collecting ducts in the pericalyceal region of the renal pyramids, which can lead to nephrolithiasis and frequently associated with impaired tubular function such as distal renal tubular acidosis. The disease knowledge is limited, especially about origin, diagnosis, and physiopathology of the disease. The disease is associated with impaired tubular function such as distal renal tubular acidosis, hypocitraturia, hypercalciuria, which suggest altered kidney medulla function. Multiparametric MRI may provide further informations about the physiopathology and help in earlier diagnosis of the medullary sponge kidney. Objective : The aim of this study is to test the hypothesis that early kidney medulla function alteration in medullary sponge kidney can be detected and characterised with multiparametric MRI. We are expecting to see in medullary sponge kidney a decreased oxygenation content in BOLD MRI (Blood oxygenation level dependent magnetic resonance imaging), and decreased ADC (Apparent diffusion coefficient) value in the medulla. Design : A monocentric prospective case/control study will be conducted in adults with medullary sponge kidney. Controls are adults patients with glomerular filtration rate > 60 mL/min/1.73m2 without kidney stone attending a renal exploration. After a screening visit, patients included will be evaluated on one day with lithiasis assessment and measurement of glomerular filtration (Urinary collection of the last 24 hours, Urine sample, Blood sample) and they will perform multiparametric magnetic resonance imaging of the kidneys.

Patients with glomerular filtration rate > 60 mL/min/1.73m2 without kidney stone attending a renal exploration.

Comparaison of R2* values measured by BOLD MRI beetween medullary sponge kidney patients and controls.

Comparaison of R2* values measured by BOLD MRI between medullary sponge kidney patients and controls. R2* is related to the level of tissue deoxyhemoglobin, which reflect tissue oxygenation. Increases in its outcome measure R2* (transverse relaxation rate expressed as per second) correspond to higher deoxyhaemoglobin concentrations and suggest lower oxygenation, whereas decreases in R2* indicate higher oxygenation.

Comparaison of ADC value measured by diffusion-weighted MRI beetween medullary sponge kidney patients and controls.

Diffusion-weighted magnetic resonance imaging (DWI) is a non-invasive method sensitive to local water motion in the tissue, which is particularly sensitive to alterations in the renal interstitium, e.g. during renal fibrosis

Comparaison of T1 Value measured by T1 mapping MRI between medullary sponge kidney patients and controls.

Comparaison of T2 Value measured by T2 mapping MRI between medullary sponge kidney patients and controls.

In medullary sponge kidney patients, evaluation of the association between kidney function and : - ADC value measured by diffusion-weighted MRI - T1 Value measured by T1 mapping MRI - T2 Value measured by T2 mapping MRI

In medullary sponge kidney patients, evaluation of the association between 24 hours calciuria and : - ADC value measured by diffusion-weighted MRI - T1 Value measured by T1 mapping MRI - T2 Value measured by T2 mapping MRI

In medullary sponge kidney patients, evaluation of the association between 24 hours citraturia and : - ADC value measured by diffusion-weighted MRI - T1 Value measured by T1 mapping MRI - T2 Value measured by T2 mapping MRI

In medullary sponge kidney patients, evaluation of the association between urine pH and : - ADC value measured by diffusion-weighted MRI - T1 Value measured by T1 mapping MRI - T2 Value measured by T2 mapping MRI

In medullary sponge kidney patients, evaluation of the association between maximum urinary osmolarity and : - ADC value measured by diffusion-weighted MRI - T1 Value measured by T1 mapping MRI -T2 Value measured by T2 mapping MRI

Inclusion Criteria: medullary sponge kidney attending medical consultation Patients with glomerular filtration rate > 60 mL/min/1.73m2 without kidney stone consent signed effective contraceptive method for women affiliated to social insurance scheme Exclusion Criteria: kidney transplant polycystic kidney diseases Chronic kidney disease (GFR < 60 mL/min/1,73m² ) MRI contraindications (claustrophobia, pacemaker, cardioverter defibrillators implantable, mechanical heart valve non MRI-compatible) Weight> 130 kg pregnancy legal protection measure (guardianship, curatorship) Deprived of liberty by a judicial or administrative decision subject participating in another research including an exclusion period still in progress at inclusion