Lecture 12: Imaging the Kidney Flashcards
What is the gold standard imaging technique for kidney imaging
Ultrasound
Can kidney stones be seen on a X-ray?
No
What information can the ultrasound give regarding the kidney
•Can be used to gain information on:
–Kidney size
–Shape
–Location and number
–Structure
–Drainage / obstruction
–Renal blood flow
What is the normal length of the kidney in ultrasound?
>10cm is normal
<9cm is abnormal and indicative of chronic disease
Which is more echobright:
A) Liver
B) Kidney
A) Liver- appears a lot brighter in the ultrasound
Normal – Liver is more ‘echobright’ than kidney
Abnormal – Kidney more ‘echobright’ than liver – implies pathological change
Why is CT with contrast is not recommended for imaging the kidneys?
–Potentailly nephrotoxic
~ weigh up risk v benefit with eGFR <30mL/min
Remember the kidneys needs to be able to excrete the contrast- toxic if patient has a low kidney function
Which imaging technique will not show kidney stones?
X-ray
What is the positives of using an MRI to image the kidney
•May be used in the assessment of:
–Renal structure (cysts / tumours)
–Renal vasculature (MRA)
What are the possible problems of using MRI in imaging the kidney?
Can cause nephrogenic systemic fibrosis in patients with a low kidney function
NSF: disease of fibrosis of the skin and internal organs reminiscent but distinct from scleroderma or scleromyxedema. It is caused by gadolinium (Gd) exposure used in imaging in patients who have renal insufficiency.
What are the positives of using a isotope scanning in imaging the kidneys?
•Gives information on:
–Structure
–Perfusion
–Excretion
–Differential Renal Function
Plain CT should be used to image?
Kidney stones
Plain MRI should be used to image?
Tumours
Most renal stones are composed of
calcium oxalate and phosphate
Define renal stone
- A solid concretion of crystal aggregate formed within the urinary space.
- Also known as •nephrolithiasis
- Formed from the combination of excreted/secreted ions within the glomerular filtrate.
Nephrolithiasis refers to
refers to the presence of crystalline stones within the kidneys
Urolithiasis refers to
refers to the presence of stones originating anywhere in the ureter