Radiology Flashcards
What is one of the most useful imaging modalities for assessment of the kidneys and collecting systems?
Intravenous urogram (IVP)
What is the most common current indication for IVP?
Evaluation of obstruction
What are 3 things that might cause obstruction?
- Stone
- Blood clot
- Tumor
What can IVP/IVU identify with regards to obstruction?
It’s level and the nature of the obstruction
What can distortion of the collecting systems be?
A secondary indication of a renal mass
Is a IVP good to identify a renal mass?
No, it is more effectively evaluated with other imaging modalities: CT and US
What is the initial screening exam for a patient with suspected renal pathology?
Abdominal plain film (KUB)
What are renal contours relatively well defined by in a KUB?
Adjacent fatty tissue in the perinephric space
True or False: KUB can help identify the contour of the urinary bladder?
FALSE
What is the prime utility of plain film radiography?
To identify calcifications or stones
What % of urinary tract calculi are calcified and generally visualized with plain film radiograph?
85%
What are calcification in pelvis typically?
They are frequently of vascular origin (phleboliths)
When is a retrograde pyelogram performed and who does it?
This is usually done in conjunction with cystoscopy and this is performed by a urologic surgeon
What is done in a retrograde pyelogram?
The distal portion of the ureter is catheterized and contrast is administered in a retrograde manner
When is a retrograde pyelogram particularly useful?
In the evaluation of kidneys which are non-functional or completely obstructed
What is a useful non-inasive imaging modality that uses high frequency sound waves to produce images of internal structures of the body?
Sonography
True or False: Kidneys are typically well demonstrated by US?
True
What part of the kidneys is US the most useful in evaluating?
The collecting systems
What is US helpful for screening?
Obstruction (hydronephrosis)
What is US an excellent assessment for?
Evaluation of renal mass (cyst v. solid)
What is the single most helpful examination of the kidney?
CT
When you do CT for a kidney, do you give IV contrast?
You usually do the scan before and after the administration of IV contrast
What is quite useful in the acute setting for evaluating the patient with suspected urinary obstruction secondary to a stone or calculi?
An unenhanced CT with helical aquisition
What is enhanced CT critical for?
The evaluation of renal masses, trauma, or infection
What can be utilized for guidance for subsequent interventional procedures such as drainage and biopsy?
US and CT
What is the exam that utilizes radioactive agents injected into the blood stream and subsequently accumulated by the kidney?
Nuclear Medicine (Scintigraphy)
What kind of exam is nuclear medicine?
It is primarily a functional exam
What is an invasive exam that is most useful for the evaluation of the renal arteries (and less commonly the veins)?
Renal angiography
Why are applications of MRI limited?
Cost
True or False: MRI is no more specific than CT in regards to evaluating a renal mass?
True
What does MRI have some potentially broader applications in?
Staging a renal mass with potential vascular involvement
What are the major components of the urinary system?
- Kidneys
- Intrarenal collecting structures
- Renal pelvis
- Ureters
- Urinary bladder
- Urethra
What are the kidneys located within?
A cone of renal fascia (Gerota’s fascia) surrounded by the fat in the perirenal space
What makes up the kidney?
Lobes that consist of pyramidal shaped medulla surrounded by cortex
What does the cortex consist of?
Proximal and distal convoluted tubules and the accompanying blood vessels
Where are the peripheral and septal cortex located?
- The peripheral cortex is immediately beneath the renal capsule
- The septal cortex extends down between the pyramids as the columns of Bertin
What can occasionally simulate a renal mass?
The columns of Bertin
What do the medullary pyramids consist of?
Collecting tubules and the long, straight portions of the loops of Henle as well as the accompanying blood vessels
What is the apex of the pyramids directed at?
The renal sinus (ant is projects into the calyces)
Are renal arteries single or multiple?
Either
What vertebral level to the renal pedicles lie at?
L1-L2 (adjacent to spine)
What is the typical sagittal diameter of an adult kidney?
9-12 cm
What does the collecting system in each kidney consist of?
Calyces and renal pelvis
How many calyces per kidney?
Usually 8-12
What shape are the calyces?
Cup-shaped
What do the ureters do?
Conduct urine from the renal pelvis to the urinary bladder