Renal US Flashcards
Bosniak Class 1: Simple cyst
- Anechoic, imperceptible (hairline thin) wall, round
- No septa, calcifications, or solid components
- water attenuation, no enhancement
Work up- Nil
Malignancy- 0%
Bosniak Class 2: Minimally complex cyst
- Septa: a few hairline-thin in which no measurable enhancement may be appreciated or Single thin septation
- Calcification; fine or a short segment of slight thickening may be present in the wall or septa
- High-attenuation- uniform in lesions (<3cm) that are sharply marginated & do not enhance
Work up- Nil
Malignancy- 0%
Bosniak Class 2F: minimally complex (needing followup)
- Septa: multiple hairline-thin in which no measurable enhancement of septum or wall is appreciated
- Calcification: may contain thick & nodular calcification, but no measurable contrast enhancement
- No enhancing soft tissue components
- Intrarenal: totally intrarenal, non-enhancing, high attenuating renal lesions >3cm
- hyper dense in CT
Work up- USG or CT followup
Malignancy- 5%
Bosniak Class 3: Indeterminate cysts
- measurable enhancement in mass w to thickened, irregular or smooth walls/septa
- Thick or multiple septation, mural nodule
Work up- partial nephrectomy
Malignancy- 50%
Bosniak Class 4: clearly malignant
- Solid mass w cystic spaces
- enhancing soft tissue components
- masses have all the criteria of Class 3 but also contain distinct soft-tissue components independent of the wall/septa
Work up- partial/total nephrectomy
Malignancy- 100%
Simple cysts
- exact cause unknown
- more common as people age
- asymptomatic; rarely cause problems
- Do Not affect renal function
- if large enough; may cause dull pain in flank, fever or upper abdo pain
- can be solitary or multiple
- can involve one or both kidneys
- anechoic fluid filled structure w posterior enhancement
Complex cysts
- may contain septation, thick walls, calcifications, internal echoes, & mural nodularity
- considered malignant until proven otherwise
Parapelvic cysts
- usually ovoid shape
- originate from the renal sinus
- most likely lymphatic in origin
- Do Not communicate w the collecting system
- largely asymptomatic; may occasionally cause pain, haematuria, hypertensionc or obstruction.
Multicystic Dysplastic Kidney Disease (MCDK)
- abnormal develop in utero
- attrib* to genetics
- affects on kidney only
- multiple cysts of varying sizes
- ‘bunch of grapes’ appearance
- non-functioning kidney
Poly cystic kidney disease
- can be autosomal (ADPKD) or autosomal recessive (ARPKD)
- both forms can lead to renal failure
ADPKD
- 20x more common
- appears later in life (>40yrs)
- by 60yo, approx 50% have end-stage renal Dx
- cysts arise from any nephron segment
- bilateral Dx
- enlarged kidneys w multiple asymmetrical cysts
ARPKD
- diagnosed in utero or shortly after birth
- can present w symmetrically enlarged echogenic kidneys that retain their shape
- ‘cysts’ are dilatations of the collecting duct
- in older children; kidneys are enlarged with echogenic cortex & medulla, & corticomedullary differentiation is lacking.
Benign solid tumours
Make up about 15-20% of all solid renal tumours in the parenchyma
4 types:
- renal adenomas
- angiomyolipomas
- lipomas
- leimyomas
Renal adenoma
- most common benign renal tumours
- arise from mature tubular cells
- almost always <3cm size
- can’t differentiate them from other solid renal tumours
Types:
- renal oncocytoma
- papillary andenomas
- echogenic or isoechoic we’ll-circumscribed lesions <3cm, but some can be larger
Angiomyolipoma
- composed of fat, muscle, & blood vessels
- tumour size varies: 1-20cm
- may be multi focal
- incidental finding
US findings:
- well circumscribed echogenic solid lesion (mostly)
