Kidneys urinary tract and suprarenal glands

Question 1

What do for kidneys

And whats the bosniak classification

Answer 1

Multi-phase Contrast CT

MR can also be used.

US often as a first cheap fast noninvasive nonionizing step.

Question 2

Congenital anomalies

Answer 2

Unilateral renal agenesis is actually kind of common

10% also has ipsilateral adrenal agenesis

Renal hypoplasia. Small kidney, opposite side often shows hyperplasia

Horseshoe kidneys.

Kidney dystopia aka ectopic kidney. Can be bilateral or unilateral.
Lumar, Sacral, Pelvic.

Question 3

Epithelial kidney tumors

Answer 3

Renal cell carcinoma, aka clear cell carcinoma
it is the most common type of kidney - arising from the renal tubular epithelial cells.

Wilms tumor
Bellini tumors, arising from the collecting ducts.

Epithelial tumor types cannot be differentiated by radiology.

Except for oncocytomas which have a central scar and spoke wheel like contrast enhancement pattern.

Question 4

Classic triad of RCC symptoms

Answer 4

Lower back pain
Palpable kidney mass
Hematuria

Not commonly seen even though its ‘classic’

Weight loss
Fever, etc.

Question 5

Mesenchymal tumors of the kidney

Answer 5

Angiomyolipoma
Fibroma
Fibrosarcoma
Lipoma
Leiomyosarcoma
Hemangioma
Juxtaglomerular tumors

Angiomyolipoma is the only one that can be clearly differentiated by radiology. It is made of fat, vessels, and smooth muscle. The high fat content of the tumor is visible by hypodensity on C1 of intensity of T1/T2.

Non-fatty tumors are hypointense on MR.

Question 6

Inflammatory kidney lesions

Answer 6

Abscesses, by CT US, MR

Acute pyelonephritis - delayed contrast enhancement
Dilation of the calyses, and thinned, fibrotic cortex.

Question 7

Nephrocalcinosis

Answer 7

calcinosis, diffuse calcium deposition.

• chronic glomerulonephritis
• renal tubular acidosis

Question 8

Kidney stones

Answer 8

Calcium oxalate an struvite stones are visible, uric acid ones ~10% are not.

All types of stones big enough can be seen on US, but it is highly skill dependent on the examiner, and on their location.
Only stones that are located in the upper 1/3rd of the ureter or right next to the bladder can be visualized.

Urolithiasis Types:

Calcium oxalate and calcium phosphate (80%). light brown stones - VISIBLE on X-RAY and CT

Struvite: Magnesium, Ammonium, and Phosphate, 20%. very dark brown and large - also usually have enough magnesium adn Calcium to be VISIBLE

Uric acid 6-7%, gray/brown - NOT VISIBLE.

Calcium oxalate/phosphate, causes

Hypercalcemia
Hyperuricosuria, excessive uric acid excretion
Alkaline urine
Struvite, magnesium, ammonium, and phosphate stones

Renal infection
Chronic urinary tract infection and alkaline urine
Uric acid stones

Half are idiopathic
Gout
Leukemia
acidic urine

Question 9

Pyelogram or pyelography

Answer 9

IV contrast material is administered and then followed by fluoroscopy as it is filtered by the kidneys and through the ureters to the bladde.r

Question 10

What is the method for imaging kidney/ureter stones

Answer 10

CT is the method of choice, and all the types of stones can be imaged.

On MRI, all stones completely lack signal and are totally dark.

Question 11

Most common sites for Ureter stones to obstruct.

Answer 11

pyelourteral junction and at the juxtavesical segment

The physiological stenoses of the ureters seen at the pyelourteral junction and at the juxtavesical segment are also clinically important as ureter stones are most commonly stuck at these sites.

Question 12

Can the bladder be examined by ultrasound

Answer 12

Yes, when it is fully distended, the bladder wall can be examined well.

Question 13

How common is bladder cancer

what are its symptoms

Answer 13

2nd most common genital/urinary cancer behind prostate cancer.

Hematuria

Increased urinary frequency
or
Occaisionally obstructive urinary retention

Starts as papillary lesions usually, can be imaged by US, then invasive.

Question 14

What probes are used for Adrenal gland scintigraphy (cortex and medulla)

Answer 14

Cholesterol-derivative labeled radioisotopes for Adrenal cortical scintigraphy.
To identify hormone producing adenomas

Adrenergic and somatostatin receptor binding labeled probes.
MIBG-for pheochromocytoma.

Question 15

Standard methods for imaging the adrenal glands

Answer 15

Difficult to find by ultrasound, especially the left adrenal gland, often obscured by stomach gas. ~80% of the time the right one can be seen, but only 40% the left.

Are seen by CT clearly, slightly less intense signal than the nearby liver parenchyma.

Enhance by contrast.

Question 16

Bosniak classification

Answer 16

Bosniak 1
simple cyst
imperceptible wall, rounded
work-up: nil
percentage malignant: ~0%
Bosniak 2
minimally complex
a few thin <1 mm septa or thin calcifications (thickness not measurable); non-enhancing high-attenuation (due to proteinaceous or haemorrhagic contents) renal lesions of less than 3 cm are also included in this category; these lesions are generally well marginated
work-up: nil
percentage malignant: ~0%
Bosniak 2F
minimally complex
increased number of septa, minimally thickened with nodular or thick calcifications
there may be perceived (but not measurable) enhancement of a hairline-thin smooth septa
hyperdense cyst >3 cm diameter, mostly intrarenal (less than 25% of wall visible); no enhancement
requiring follow-up: needs ultrasound/CT follow up - no strict rules on the time frame but reasonable at 6 months
percentage malignant: ~ 5% 6
Bosniak 3
indeterminate
thick, nodular multiple septa or wall with measurable enhancement, hyperdense on CT (see 2F)
treatment/work-up: partial nephrectomy or radiofrequency ablation in elderly or poor surgical candidates
percentage malignant: ~55% 6
Bosniak 4
clearly malignant
solid mass with a large cystic or a necrotic component
treatment: partial or total nephrectomy
percentage malignant: ~100%