Kidneys

• What imaging tests can we do on the kidneys?

  • ultrasound
  • Urography (x-ray)
  • CT
  • MRI
• What nuclear medicine tests can we do at the kidneys?

  • Renal Scintigraphy
  • Radiorenography
  • Blood flow kidney
  • Radionuclide diagnosis of bladder
  • Clearance measurement methods
• what is the function of static renal scintigraphy?

  check kidney function

  provide morphological information on each kidney.
• what Rf is used to show individual renal function in renal scintigraphy?

  • 99mTc DTPA,
  • 99mTc MAG3 (mercaptoacetilglycerine0
• what Rf is used to visualise the parenchyma in renal scintigraphy?

  • 99mTc-DMSA (dimercaptosuccinic acid),
  • 99mTc-GH (glucoheptonate)
• what is the preferred Rf in static renal scintigraphy?

  99mTc labelled DMSA

  • becomes fixed in the proximal renal tubular cells of cortical and juxtamedullary nephrons
• what is the procedure of renal scintigraphy?

  1. IV injection of RF dose 80-160 MBq/70Kg (in pediatric studies the dose has to be scaled down)measuring the residual activity in the syringe;
  2. 2.5-5h pause with high intakes of 0.5L of fluid
  3. Examination is supine or standing
  4. Front, back, and posterior oblique projections using gamma camera
  5. Renal accumulation calculated by a computer
• indications for renal scintigraphy?

  • morphological studies of renal cortex
  • Location of ectopic kidney
  • renal parenchymal defects (cysts, tumors, ischemic areas)
• advantages of renal scintigraphy?

  • Most specific method for detecting changes in kidneys
  • More specifically assess separate functions mainly in mobile kidney
  • Detectability of mobile kidney
• disadvantages of renal scintigraphy?

  • Long interval between application and examination
  • Radiation exposure (but less than CT), cooperation of children
• Types of radiopharmaceuticals used in renal scintigraphy?

  • Individual renal function: 99mTc DTPA, 99mTc MAG3 (mercaptoacetilglycerine)
  • Visualization of parenchyma: 99mTc-DMSA (dimercaptosuccinic acid), 99mTc-GH (glucoheptonate)
• What is separate renal function?

  determination of the relative contribution of each of the two kidneys to total renal function.
• what is the function of DMSA imaging in renal scintigraphy?

  DMSA imaging provides an assessment of:

  • size and position of the kidneys
  • differential function
  • expressed as a percentage of the total function.
  • parenchymal defects => scars, cysts, tumors, ischemic areas in renal hypertension
  • morphological abnormalities such as duplex and horseshoe kidney
• what is the principle of dynamic renal scintigraphy?

  the uptake, transit (through nephron) and excretion of the RF
• what Rf is used in dynamic renal scintigraphy?

  • 99mTc DTPA – for glomerular filtration rate measurement
  • 99mTc MAG 3 – for tubular exertion rate
  • 99mTc EC (ethylene dicysteine)
• what is the patient prep for dynamic renal scintigraphy?

  • patient should be hydrated before the study (500ml 30mins before)
  • bladder should be emptied before entering the camera room
• dynamic renal scintigraphy procedure?

  1. Patient is supine or sitting (migrating kidney)
  2. Hydration of the patient with 0.5L of fluid 30 mins before examination
  3. Measurement of the full syringe by gamma camera before application
  4. IV application immediately and 20s dynamic record during 20-30 mins in dorsal projection
  5. Measurement of empty syringe after examination
  6. Blood sampling for certain modifications of examinations
  7. Delated emptying – scintigram after urination
• indications for dynamic renal scintigraphy

  • Measurement of contribution of each kidney global renal function
  • Evaluation of obstructive nephropathy and obstructive uropathy => Diuretic renography
  • Presence of renovascular disorder as a cause hypertension => Captopril intervention
  • Evaluation of renal transportation à Angioscintigraphy
• advantages of dynamic renal scintigraphy

  • High reproducibility- automated evaluation
  • Radiation exposer is higher than functional tests but lower than IVU or CT
  • Allows the assessment of overall well-separated takes of parenchymal disorders and urine output
• disadvantages of dynamic renal scintigraphy

  • Only assesses the current state
  • Problem of accurate assessment of the separated function for displaced kidneys
• what is diuretic renography?

  a nuclear medicine examination performed to analyze urinary drainage patterns in patients with suspected renal or ureteral obstruction, using furosemide diuretic.
• what are the indications for diuretic renography?

  • suspected obstructive nephropathy or obstructing uropathy associated with hydronephrosis or renal stones
  • suspected vesicoureteral or pelvo-ureteral stenosis
• In which procedure do we use capto-scintigraphy?

  dynamic renal scintigraphy to determine the presence of renovascular disorders as a cause of hypertension
• what disorders are made worse with Captopril?

  renovascular
• Captopril inhibits this what?

  vasoconstriction
• what is the indication that Captopril has been absorbed?

  If the diastolic pressure falls by 10 mmHg or more during the subsequent hour after the oral administration of Captopril
• How many phases do we have in renography?

  • Phase I - vascular (0-30sec)
  • Phase II - functional/secretory (peaks at 3-5min)
  • Phase III - excretion
• what occurs in Phase I of renography?

  • shows blood flow and initial uptake.
  • the first increase in the inflow curve (Rf injected)
• what occurs in Phase II of renography?

  • slow ascent phase after 30sec (RF accumulates in tubular bb)
  • Norm = rise of at least 50% phase I.
  • The top curve Tmax= time.
  • Characterized by parenchymal function.
• what occurs in Phase III of renography?

  • Value hollow drainage system impairment parameter
• what can you see the renal perfusion test diagram?

  • Steepness of the rise is a measure of parenchymal function.
  • Normal curve = surge by 30 seconds
  • Parenchymal curve = if parenchymal function decline, reduces amplitude leads to prolongation of Tmax - delays peak.
  • Isostenuric type = horizontal curve, shows severe renal hypofunction
• Fill the blanks

  A) normal

  B) parenchymal

  C) isostenuric

  D) afunction

  
• Fill the blanks

  A) obstruction

  B) normal[

  C) hypofunction

  D) slow flow

  E) spastic

  
• Main advantage for dynamic renal scintigraphy compared to ultrasound?

  High reproducibility of the method

  • automated evaluation. It allows assessment of parenchymal disorders and urine output.
• Types of renography

  • Dynamic renal scintigraphy,
  • diuretic renography
  • direct and indirect cystography
• what are the indications of kidney angiscintigraphy?

  • Acute tubular necrosis
  • Problems of graft rejection=> acute and chronic rejection
  • Stenosis of renal artery (Captopril = diagnostic test)
  • Problems urine flow
  • Urinoma (urinal is leaking into the abdominal cavity)