Imaging Flashcards
Uses for renal imaging?
Exclude obstruction along kidney, ureter or bladder
Scope usually handles the bladder
Measure renal size (cortical thickness)
Cyst or Solid (polycystic disease or tumor)
As primary care providers …. What test do we order?
Types of Renal Imaging
KUB Ultrasound IVP CT MRI Renal Arteriography/Venography Retrograde or anterograde pyelography Nuclear Imaging Studies Voiding Cystourethrogram
What is a KUB?
What are we looking for?
Advanatages? 3
- Kidney-Ureter-Bladder (Flat plate)
- Looking for stones (calcium stones, strubright stones- formed by bacteria, cysteine stones)
- Inexpensive
- Scout film for IVP
- Lower Abdominal Film so you can check out some abdominal pathology
- What is a Sonography (The U/S)?
- Disadvantage of this?
Why is this the first test done is renal disease? 4
- Echoes of high frequency sound waves
- Operator dependent; limited by body habitus (keep this in mind)
- Usually the first test done in renal disease…
- fast and
- cheap
- No contrast!
- Safe…expectant mothers with pain!
How do we scan the following organs: RIght kidney? 3 Liver? Left kidney? What impedes anterior scanning?
Right kidney scanning approach: anterior, lateral, posterior
Liver is the acoustic window
Left kidney: requires a posterior approach, through the spleen
Air-filled bowel impedes anterior scanning
Sonography applications?
4
- Renal mass characterization:
cyst vs solid not to mention the size and position of the kidney - Detects Obstruction… Hydronephrosis (dilatation of the renal pelvis)
- Polycystic Kidney Disease (structural abnormality)
- Chronic renal failure (functional abnormality)
What stones wont be seen on an X-ray?
uric acid stones
Sonographic Appearance
- What is normally not seen?
- what structure is black when visible?
- What structure is hypoechoic?
- What structure is mid-gray, less echogenic than liver or spleen?
- What structure is smooth and echogenic?
- Ureters are normally not seen
- Renal pelvis is black when visible
- Medullary pyramids are hypoechoic
- Cortex is mid-gray, less echogenic than liver or spleen.
- Capsule is smooth and echogenic
- IVP (Intravenous Pyelogram)
other names? 2 - When do we use this?
- How is this done?
- BUT what is the gold standard for suspected stones?
- Other names
- Pyelography,
- Intravenous Urogram) - Suspected Obstruction of flow of urine and function of kidney
- Rapid IV bolus of dye with delayed films
- CT scans
CT Scan is used for what? 4
What are easily visualized?
What is dilated?
- Evaluate renal tumors and
- local spread of renal malignancy
- Trauma (extra-peritoneal organ)
- Renal colic (Helical CT with stone protocol)
- Small calculi easily visualized
- Collecting system dilatation
What CT can detect smaller cyst? (as small as?)
High-resolution CT angiography
2-3 mm in size
What Can identify urothelial tumors better than IVP?
CT Urography
Magnetic Resonance Imaging: Renal mass characterization
- Usually used for what?
- What are the advanatges? 4
- Usually reserved for patients with CT contraindications (contrast)
- -Great tissue contrast (good for complex masses)
-No ionizing radiation and it’s expensive
-Invasion from tumors…stages kidney tumors
-They have MRU’s
May be a better study to check on anatomical renal abnormalities
Renal Arteriography: Aortography (Angiogram)
- How is this accomplished?
- What do we need to know before we do this?
- Uses?
- Gold standard for what?
- What other procedures are used to help with this? 3
- Invasive with contrast
- Need to know the Cr unless it’s recent!
- Can also show you the anatomy before transplant
- Gold standard for Renal Artery Stenosis (RAS)
- Doppler U/S
- MRA
- CTA are used as well…you can stent with the angio
Renal Venography still remains useful for the diagnosis of what?
renal vein thrombosis
- Retrograde/Anterograde Pyelography is used to diagnose? 2
- How do we do this procedure?
- Helps with what?
- Used to evaluate what?
Now we usually do CT or US
- Dx
-urinary tract obstruction or
-tumors - Injects contrast into the ureter to visualize the ureter and kidney
- Helps with placement of ureteral stents
- Used to evaluate trauma
Now we usually do CT or US
Nuclear Imaging
- Dynamic renal scan, renogram, DTPA or Mag3 are all the dyes. And what are they used to evaluate?
- Whats a Lasix renal scan used for?
- What is a captopril scan used for?
- Renal perfusion and function
- Obstruction
- Renovascular HTN
No side effects to dye
Patient lies still for clear pictures and a radioisotope tracer is injected into the vein.
A gamma camera detects the radioactivity and images are projected onto a computer
Can find out what percentage each kidney contributes to the total kidney function
1. Voiding Cystourethrogram is used to evaluate what? 4 2. Invasive or noninvasive? 3. How is it done? 4. What does the procedure end with? 5. What is this done under?
- Used to evaluate
- urethra,
- bladder,
- ureters, and
- kidney - Noninvasive
- Patients bladder is filled with contrast via a catheter, and once the bladder is full inspection for reflux into the ureters
- Procedure ends with the patient voiding
- This is done under fluoroscopy
Voiding Cystourethrogram VCUG: 1. Is usually done in what demographic? 2. what are we usually searching for? 3. In males what are we evaluating them for with a VCUG? 4. Pt voids under fluoro with what?
- Usually in children with history of UTI
- Searching for vesicoureteral reflux
- In males, evaluate for urethral abnormalities: posterior urethral valves
- Patient voids under fluoro with spot films
In a normal, negative VCUG contrast should not do what?
reflux into the ureter
Advanatges of US?
2
Ultrasound is
- very non invasive and is
- good to use to check the anatomy and for hydronephrosis
CT is still the gold standard for? 2
- Renal stones
2. Diagnose renal tumors
- Along with renal venography and CT, MRI is reliable for the diagnosis of what?
- It is also playing an increased role in what?
A plain film of the abdomen is not commonly performed as the first study in patients with suspected renal disease
- renal vein thrombosis.
- suspected renovascular hypertension
A plain film of the abdomen is not commonly performed as the first study in patients with suspected renal disease
Early detection of VUR and scarring is possible with what?
2
- radioisotope scanning with DMSA or MAG3 and
2. a voiding Cystourethrogram
- Renal arteriography used to treat and diagnose?
2. And evaluate for what?
- stenosis
2. evaluate for transplant
A 64 yr old man has a Cr of 2.3 and has been diagnosed with chronic renal failure. What is the best initial imaging test?
U/S of the kidneys
A 56 yr old woman presents with flank pain and bloating. What would be your initial test?
KUB
Your pt has proteinuria on his UA x3. All other labs are WNL. You decide to consult nephrology. What would be the best initial study to do prior to him being seen by the specialist?
U/S of the kidneys
