Kidney Sodium Functional Imaging

Study Overview
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Brief Summary
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The corticomedullary gradient is largely responsible for developing the gradients that are needed to concentrate urine (more solutes and less water). The ability of the kidneys to produce concentrated urine is a major determinant of the ability to survive the warm weather. When temperatures are high, we lose water through sweat, and so the kidneys retain water to maintain fluidity in the blood. The maintenance of a sodium (salt) gradient is required for urine concentration because increased medullary sodium concentration increases the reabsorption of water into the kidney, to be redistributed in the blood. The purpose of this study is to know if the corticomedullary gradient is altered in patients across a wide spectrum of kidney disease using sodium Magnetic Resonance Imaging (MRI), a machine that takes pictures and measures the salt content in the kidneys. 23Na kidney MRI, will provide functional MR of the kidney as a non-invasive tool to describe medullary function to improve management of chronic and kidney disease.

Detailed Description
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This study is a pilot exploratory study (preliminary project to assess the use of a kidney sodium coil across a wide spectrum of kidney disease). Approximately 200 patients from the London Health Sciences Regional Renal Program will be recruited. This study involves two visits at Robarts Research Institute or St. Joseph's Hospital, London, Ontario depending on scanner availability, lasting approximately 2 hours. At the first study visit participants will undergo a sodium MRI scan of your kidneys. Prior to the scan, participants will have their sitting blood pressure and heart rate measured three times consecutively using a standard automatic blood pressure monitor. In addition to this, participants will be asked to provide a spot urine sample and have blood work done. If participants have been treated for nephrolithiasis, they will be responsible for completing a 24-hour urine volume test sometime the week before the MRI scan.

Official Title
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Kidney Sodium Functional Imaging: Evaluation of Kidney Medullary Sodium Content Using 23Na MRI in Kidney Disease

Conditions
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Chronic Kidney Disease, Nephrolithiasis, ADPKD

Intervention / Treatment
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* Diagnostic Test: Sodium-23 MRI


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age ≥ 18 years For healthy controls: lack of kidney disease, heart failure, liver cirrhosis and peripheral edema For CKD stage 1-5: Estimated GFR < 90 mL/min/1.73m² For patients on maintenance hemodialysis or peritoneal dialysis: more than 3 months duration of therapy Exclusion Criteria: Pregnant, breastfeeding or intending pregnancy Contraindication to MRI Inability to tolerate MRI due to patient size and/or known history of claustrophobia. Mechanically implanted, electrically, or magnetically activated device or any metal in their body which cannot be removed, including but not limited to pacemakers, neurostimulators, biostimulators, implanted insulin pumps, aneurysm clips, bioprosthesis, artificial limb, metallic fragment or foreign body, tattoos, shunt, surgical staples (including clips or metallic sutures and/or ear implants.)

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Adult CKD stage 1-5 participants<br>Age greater than or equal to 18 years Estimated GFR < 90 mL/min/1.73m² | Diagnostic Test: Sodium-23 MRI<br>* Participants will lay in the MRI bed for approximately 60 minutes during scanning while the MRI technologist takes detailed pictures of their kidneys.<br>|
| Adult transplanted participants<br>• Age greater than or equal to 18 years | Diagnostic Test: Sodium-23 MRI<br>* Participants will lay in the MRI bed for approximately 60 minutes during scanning while the MRI technologist takes detailed pictures of their kidneys.<br>|
| Adult dialysis participants<br>Age greater than or equal to 18 years More than 3 months duration of therapy | Diagnostic Test: Sodium-23 MRI<br>* Participants will lay in the MRI bed for approximately 60 minutes during scanning while the MRI technologist takes detailed pictures of their kidneys.<br>|
| Adult ADPKD<br>• Age greater than or equal to 18 years | Diagnostic Test: Sodium-23 MRI<br>* Participants will lay in the MRI bed for approximately 60 minutes during scanning while the MRI technologist takes detailed pictures of their kidneys.<br>|
| Adults treated for nephrolithiasis<br>• Age greater than or equal to 18 years | Diagnostic Test: Sodium-23 MRI<br>* Participants will lay in the MRI bed for approximately 60 minutes during scanning while the MRI technologist takes detailed pictures of their kidneys.<br>|
| Adult healthy controls including kidney donors<br>Age greater than or equal to 18 years Lack of kidney disease, heart failure, liver cirrhosis and peripheral | Diagnostic Test: Sodium-23 MRI<br>* Participants will lay in the MRI bed for approximately 60 minutes during scanning while the MRI technologist takes detailed pictures of their kidneys.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Exploratory cortico-medullary gradient measurement | Exploratory cortico-medullary gradient measurement in a large range of kidney disease by measuring sodium medullary to cortex ratio with23Na kidney MRI in: 1) stage 1-5 CKD patients 2) transplanted patients 3) dialysis patients 4) ADPKD patients 5) nephrolithiasis patients (characteristically associated with salt loading) 6) healthy controls including kidney donors | Throughout study visit, on average 2 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Urinary osmolarity | To evaluate the relationship between sodium medullary to cortex ratio and urinary osmolarity | Throughout study visit, on average 2 hours | 
| Renal Function | To evaluate the relationship between sodium medullary to cortex ratio and renal function | Throughout study visit, on average 2 hours | 
| Native and transplanted kidney | To compare sodium medullary to cortex ratio between native kidney and transplanted kidney | Throughout study visit, on average 2 hours | 
| Kidney biopsy | To compare sodium medullary to cortex ratio between transplanted kidney and kidney biopsy | Throughout study visit, on average 2 hours | 
| Residual renal function | To evaluate sodium medullary to cortex ratio in dialysis patients and renal residual function | Throughout study visit, on average 2 hours | 
| Nephrolithiasis | To compare sodium medullary to cortex ratio between healthy control and patients who have nephrolithiasis | Throughout study visit, on average 2 hours | 
| ADPKD | To evaluate the ability to measure sodium medullary to cortex ratio in autosomal dominant polycystic kidney disease | Throughout study visit, on average 2 hours | 
| Clinical practice | To determinate if measurement of sodium medullary to cortex ratio measurement is meaningful in clinical practice | Throughout study visit, on average 2 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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cortico-medullary gradient