RAF

The Renal Artery Function (RAF) test is a non-invasive diagnosis imaging test with ultrasound machinery that examines blood flow to the renal arteries. It is vital for diagnosing and tracking medical issues that impact blood supply to the kidneys like renal artery stenosis, kidney disease, and hypertension. 

The test employs Doppler ultrasound to capture the renal arteries, including measuring blood velocity and its waveform. There are no side effects from this test and no pain experienced with this and no radiation or containment agents are needed. 

The RAF test measures: 

• Renal arteries’ blood flow and waveform. 
• Peak systolic velocity (PSV) and end-diastolic velocity (EDV) in renal arteries. 
• Resistive index (RI) and pulsatility index (PI) of renal arteries. 

These parameters assist in evaluating the blood flow, functions, and any anomalies of the renal arteries. 

• To confirm and follow the course of renal artery stenosis or any kidney abnormality. 
• To assess the perfusion of the kidneys in hypertensive patients. 
• To follow the effectiveness of treatment measures for renal artery stenosis or any significant kidney disease. 
• To check on the kidney reserve in chronic kidney disease patients. 

This test is minimally invasive, which renders it both safe to undertake and risk-free. Patients, however, may face difficulty while undertaking the test in the occurrence of the following conditions: 

• Severe obesity 
• Presence of Pacemakers or other implantable devices 
• Gaseous/Bowel Obstruction 

Also, some conditions may be more difficult or impossible to diagnose such as, but not limited to: 

• Lesions of small or branch renal arteries 
• Distal renal artery segment lesions, 

The RAF test consists of the following interrelated elements. 

• Waveform and blood velocity in the renal arteries 
• Vessel wall thickness and diameter 
• Stenosis or occlusion, or both, exist 

Adjustments may apply depending on the patient's considerations such as: 

• Age 
• Pre-existing medical problems (hypertensive, diabetic, etc) 
• Kidney ailments 

The RAF test is warranted in the following patients: 

• Fulfilling the criteria of renal artery stenosis or other forms of kidney disease 
• Having hypertension or poorly controlled high blood pressure 
• Suffering from any form of chronic renal disease or end-stage renal disease 
• Having undergone a kidney transplant 

The RAF test will provide the following benefits: 

• The ability to identify and diagnose renal artery stenosis or kidney disease early in the disease progression 
• Assessing the effectiveness of the treatment for renal artery stenosis or kidney disease 
• Assessment of renal function in the totality of chronic kidney diseases 
• Removal of specimen for examination that causes less trauma to the body 

The conditions can be diagnosed with the RAF test: 

• Renal artery stenosis 
• Kidney diseases 
• High blood pressure 
• Chronic renal failure 
• End-stage kidney failure 

For patients to prepare for a test they will have to: 

• Make sure to fill in all the details in the medical history and examination parts. 
• For at least 30 minutes before the test, smoking and caffeine consumption should be avoided. 
• Removing all jewellery and articles of clothing that can interfere with the test is essential. 
• During the test, patients will lie down flat and remain still. 

Prerequisites: None. 

Eligibility: All patients are eligible for the test but may not be so if they are from the severely obese category or suffering from a gas mass or bowel obstruction. 

Procedure for Taking the Test: Patients will lie flat on an examination table; a technician will then apply a gel to the abdominal area. Then the technician will capture the renal arteries images with a Doppler ultrasound device. 

Caution Before the Test: Patients should tell their healthcare provider about any medical prescription they are taking and any allergies.