Imaging

Question 1

limitations of renal US? (3)

Answer 1

1. Obesity may make imaging of kidneys difficult
2. Modality is very operator-dependent (esp. doppler ultrasound)
3. Ureters are not fully visualized

Question 2

2 limitations of angiography?

Answer 2

1. Same as with IVP and contrast- enhanced CT as regards contrast-related adverse reactions and contraindications
2. Invasive

Question 3

usuae of VCUG? (3)

Answer 3

1. Evaluate lower urinary tract obstruction
2. Evaluate bladder and urethral trauma
3. Evaluate vesicoureteral reflux

Question 4

limitation of retrograde pyelography? (2)

Answer 4

1. Invasive procedure—requires cystoscopy with placement of catheters in ureters
2. May cause trauma or potentiate infection

Question 5

2 limitations of CT scan?

Answer 5

1. Same as for IVP if I.V. contrast is used

2. Calyces not well seen unless dilated

Question 6

5 uses of CT scan?

Answer 6

1. Stones – uses unenhanced (no contrast) helical (spiral) CT scanning.
2. Renal masses
3. Abscesses – renal and perirenal
4. Trauma – renal and other organs
5. CT angiography—uses I.V.contrast to evaluate renal vasculature, collecting system, ureters and bladder

Question 7

Retrograde Pyelography uses (4)

Answer 7

1. Detect stones or other obstructing lesions in renal pelvis or ureter
2. Assess non-visualization of kidney on IVP
3. Detect lesions in renal pelvis or ureter in patients allergic to intravenous contrast
4. Place ureteral stent

Question 8

limitations of IVP (4)

Answer 8

1. Severe reactions to iodinated radiocontrast—
   a. Bronchospasm, anaphylaxis
2. Minor reactions to radiocontrast—eg. itching, hives, nausea/vomiting, flushing
3. Nephrotoxicity from radiocontrast—Causes acute kidney injury.
   ― Contraindicated in patients with pre- existing severe kidney disease.
   ― Use with caution and with adequate pre-hydration in patients with mild to moderate kidney disease or diabetes and in the elderly.
4. May precipitate heart failure and/or acute pulmonary edema secondary to osmotic load of I.V. contrast (less likely with newer isoosmolar agent).

Question 9

Limitation of KUB? (3)

Answer 9

1. Low sensitivity and specificity (Provides only a crude index of renal anatomy)
2. Renal outline and calcifications may be obscured by overlying bowel gas or stool
3. Precise localization of calcifications cannot be determined

Question 10

uses of angiography? (3)

Answer 10

1. Direct imaging of renal vasculature, both arterial and venous
   a. vascular malformations
   b. renal artery stenosis
   c. renal vein thrombosis
2. Assess renal masses
3. Interventional angiography***
   a. renal artery angioplasty and stenting
   b. renal vascular embolization, eg. for intrarenal hemorrhage or renal mass management

Question 11

limitations of MRI?

Answer 11

Expense, claustrophobia and metallic devices in patient

Question 12

The renal parenchyma is well seen on a retrograde pyelogram. TRUE or FALSE

Answer 12

false

Question 13

Limitations of VCUG?

Answer 13

Invasive; involves bladder catheterization

Question 14

4 uses of KUB?

Answer 14

1. Identify kidney size, location, contour and orientation
2. Detect calcifications in kidney and urinary tract. About 90 perc of upper tract calculi contain enough calcium to be seen on plain films.
3. Used as initial, “scout film”, prior to contrast injection in an IVP study
4. Assess ureteral stent placement

Question 15

Retrograde pyelography can safely be performed in a patient who has had a previous adverse reaction to an IVP. TRUE or FALSE

Answer 15

true

Question 16

Use of renal US? (5)

Answer 16

1. Assess kidney size and shape, cortical thickness and/or scarring, and corticomedullary differentiation
2. Detect obstruction (hydronephrosis)**
3. Detect renal masses and distinguish cystic from solid masses**
4. Useful when contrast or radiation is contraindicated
   eg. renal failure, reactivity to contrast, pregnancy**
5. Color doppler ultrasound can visualize blood flow in renal arteries and veins

Question 17

use of Radionuclide Imaging (Nuclear Scanning) (5)

Answer 17

1. Measure glomerular filtration rate and renal plasma flow
2. Measure “split” renal function; eg. pre-nephrectomy
3. Evaluate renovascular hypertension (renal artery stenosis)
4. Distinguish obstructive vs. non-obstructive hydronephrosis
5. Detect and monitor vesicoureteral reflux

Question 18

The ureters can be seen on the scout film of an IVP. TRUE or FALSE

Answer 18

False

Question 19

limitations of radionuclide imaging (nuclear scanning) (2)

Answer 19

1. Not useful in assessing causes of renal failure or seeing structural detail in kidney
2. . Contraindicated in pregnancy

Question 20

T or F… most renal stones can be seen on KUB?

Answer 20

true

Question 21

4 uses of MRI?

Answer 21

1. Delineate renal architecture, including corticomedullary differentiation, especially when used with I.V. gadolinium for enhancement
2. Detect renal artery stenosis and renal vein tumor or thrombus
3. Diagnose and stage renal cell carcinomas
4. Useful when iodinated contrast media is contraindicated, except in CKD

Question 22

3 uses of IVP or IVU?

Answer 22

1. Assess kidney size, location, contour and orientation
2. Assess appearance of collecting system (calyces and renal pelvis), ureters and bladder
   a. detect obstruction (stones or tumors)
   b. detect renal calcifications
   c. detect renal trauma resulting in extravasation of radiocontrast
3. Detect renal, ureteral and bladder masses
   a. If under 3 cm, less then 50 perc are detectable

Question 23

Three sites where stones tend to lodge?

Answer 23

UPJ
Pelvic brim
UVJ