RENAL IMAGING Flashcards
What are the main imaging modalities for kidneys?
- Radiography
- Ultrasonography (US)
- Computed tomography (CT) scan
- Magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA)
- Radionuclide imaging
- Kidney angiography
Each modality has specific uses and advantages in kidney imaging.
What are the types of radiography used in kidney imaging?
- Plain film
- Excretory urography (EU)
- Retrograde pyelography
- Cystography
Radiography is often the first step in assessing kidney conditions.
What is excretory urography (EU) replaced by?
- Ultrasonography (US)
- CT urography
- MR urography
EU is less sensitive for kidney masses compared to these modalities.
What is the purpose of retrograde pyelography?
To evaluate ureteral obstruction or cancer through the injection of contrast material into the ureter.
What phases are involved in a CT urogram? ACNE
- Unenhanced axial CT
- Enhanced CT with corticomedullary phase
- Nephrographic phase
- Excretory phase imaging
These phases help in detailed visualization of kidney anatomy and function.
What are the main uses of ultrasound (US) in kidney imaging?
- Estimating kidney size
- Assessing echogenicity
- Preferred for suspected obstruction
- Differentiates solid from cystic masses
- Guides interventional procedures
US is a non-invasive method that provides real-time imaging.
What can ultrasound (US) evaluate in kidney transplants?
- Parenchymal echogenicity
- Masses
- Fluid collections
- Ureteral obstruction
- Vascular complications using Doppler
US is vital for post-transplant assessment.
What are the strengths of ultrasound (US) in kidney imaging?
- Sensitive for fluid collections and cysts
- Differentiates cortex and medulla
- Shows kidney contour and blood flow
- Safe and low cost
These strengths make US a preferred initial imaging choice.
What are the weaknesses of ultrasound (US)?
- Limited pelvicalyceal detail
- Limited ureter visualization
- Operator dependent
These limitations can affect diagnostic accuracy.
Which imaging modality is superior for indeterminate kidney masses?
Computed tomography (CT)
What does the Bosniak classification categorize?
Cystic kidney masses into categories I-IV.
Which Bosniak categories are nonsurgical?
- Categories I
- Category II
These categories generally do not require surgical intervention.
What is the purpose of magnetic resonance angiography (MRA)?
To evaluate renal artery stenosis and map vascular anatomy.
What are the limitations of MR urography?
- Insensitive for kidney calculi
- Long imaging times
- Expensive
These factors can limit its use in certain scenarios.
What is the concern with MRI in patients with pacemakers?
Requires coordination with cardiology; possible with newer pacemakers.
What does radionuclide kidney imaging estimate?
- GFR
- Renal plasma flow
- Differentiates ATN from rejection
- Evaluates urinary extravasation
Radionuclide imaging is useful for functional assessment of the kidneys.
What are glomerular filtration agents used in radionuclide imaging?
- 99mTc-DTPA
- 99mTc-MAG3
These agents help in assessing kidney function.
What is the primary use of kidney angiography?
To evaluate renal artery diseases and for preoperative evaluation of donor kidney.
What is the preferred imaging modality for acute flank pain?
Computed tomography (CT)
What does CT evaluate in kidney trauma?
- Severity of injury
- Extent of injury
- Delayed scan for urinary extravasation
CT is crucial for trauma assessment.
What imaging techniques are used in diagnosing hypertension?
- MRI
- CTA for renovascular hypertension
- US Doppler
- ACE-I renography
These techniques help identify causes of secondary hypertension.
What are the advantages of Doppler ultrasound?
- No radiation
- Low cost
Doppler ultrasound is beneficial for assessing blood flow.
What are the disadvantages of CT angiography?
Requires contrast and has exposure to radiation.
What is a contraindication to IV contrast?
- Previous allergic reaction
- Concern for nephrotoxicity
- Asthma
- Multiple allergies
- Volume depletion
- Pregnancy
Awareness of these contraindications is essential for patient safety.
