TEST 1

Urinary and Reproductive Systems

Kidney location

T12-L3

The upper poles of the kidneys are protected by ____ and are ______

ribs; closer to midline

which kidney is lower?

right

Renal ____ are anterior to _____

veins; arteries

How are the kidneys situated in the abdomen?

upper pole more posterior, following the lordotic curve

ureters are ____ to kidneys

anterior

Kidneys are ____ from medial to lateral borders and medial border is more _____

oblique; anterior

Why are the position of the kidneys relatively fixed?

adipose tissue, renal fascial attachments and surrounding organs

Factors influencing kidney position

respiration, change in position, body habitus

Respiration can change kidney position by ____

1 inch

change in body position changes kidney position by _____

1-2 inches

Ureters enter the bladder from a _______ position

postero-lateral

Areas of narrowing in Renal System

uretero-pelvic junction, pelvic brim, uretero-vesicular

urography procedure types

KUB xray, intravenous urography, retrograde urography, excretion urography/cystography

KUB X-ray Purpose

obtain baseline and as follow up

intravenous urography purpose

visualization of collecting system to assess latency

Can ureters be fully seen on a coronal slice and why?

no bc they follow lordotic curve

retrograde urography

non-functional exam of urinary system where contrast is injected directly into the pelvicalyceal system by catheterization

Retrograde urographies a ________ procedure

minor surgical

cystography

non-functional examination of bladder by injecting contrast through urethral contrast

Voiding Cystography/Cystourethrography

patient voids following dye instillation into bladder via catheter or IVP

Voiding cystography identifies issues with the _____

urethra

Renal Agenesis

failure of kidneys to develop

what type of renal agenesis is more common?

unilateral causing remaining kidney to hypertrophy

bilateral renal genesis

associated with other anomalies and usually incompatible with life

What can be used to complement the assessment of renal genesis?

U/S and CT

Radiographic appearance of renal agenesis

• hypertrophy of single kidney

• absence of renal shadow on opposite side

• supernumerary

supernumerary kidney

rare and causes secondary infections

hypoplasia of kidney

incomplete development of one or both kidneys; good function and normal anatomy

what typically occurs with hypoplasia of kidney

compensatory hypertrophy

Kidney Hypoplasia should be differentiated from _______

acquired atrophic kidney

Acquired Atrophic Kidney

small contracted with reduced renal parenchyma volume resulting from vascular or inflammatory disease

Malrotation of Kidney

rotation on longitudinal or horizontal axis and is often asymptomatic

ectopic kidney

failure of kidney to ascend from its original low embryonic position in the pelvis

horseshoe kidney

kidneys fused across midline usually at lower poles causing anterior exit of ureters and malrotated kidneys

Horseshoe Kidney Radiographic Appearance

• renal pelves close together and abnormal appearance due to malrotation

• inferior poles closer together than upper poles

• compression of ureters by isthmus tissue

• calyces directed backward or medially rather than laterally

Duplication of Kidney types

complete or incomplete

complete kidney duplication

two pelvis each with a ureter and ureteral opening

incomplete kidney duplication

ureters join prior to bladder entry in normal location; less likely to cause symptoms

Kidney duplication complications

obstruction, reflux, infection due to increased surface area thus opportunity

ureterocele

cystic dilation of distal ureter at its insertion to the bladder

ureterocele radiographic appearance

cobra head sign

post urethral valves

thin transverse membranes in the urethra found almost exclusively in males causing bladder outlet obstruction

post urethral valves best demonstrated on ______

voiding cystourethrogram

Post urethral valves may lead to…

severe hydronephrosis, hydrometer and renal damage

post urethral valves treatment

extensive surgery

IVU

intravenous urogram

IVU Indications

abdo/pelvic masses, renal calculi, kidney trauma, flank pain, hematuria, pre-op pelvic surgery, renal failure, hypertension, UTI

What imaging modalities have replaced IVU?

U/S, CT, CT/MR urography

IVU Contraindications

severe sensitivity to iodine, anuria, multiple myeloma, severe hepatic or renal failure, pheochromocytoma, Glucophage drug

anuria

no urine excretion and high BUN

Glucophage

metformin; drug for non insulin dependent diabetes

purpose of renal function assessment for contrast imaging

ensure safe administration of iodinated contrast and reduce risk of contrast-associated kidney injury

Blood Urea Nitrogen (BUN)

waste produce from protein metabolism in the liver, filtered by kidneys

BUN influenced by:

hydration, diet, liver function

BUN in Renal Function Assessment Bloodwork

supportive value only

Creatinine

waste product from muscle metabolism filtered by the kidneys

Creatinine in Renal Function Assessment

more specific indicator of renal function used to calculate eGFR

eGFR

reflects overall kidney function accounting for age and sex

What is being assessed in Renal Function Assessment Bloodwork?

BUN, creatinine, eGFR

eGFR low risk

>60

eGFR indicating caution

30-60

eGFR <30

avoid or modify contrast

Patient Prep for IVU

low residual diet, laxative, NPO after midnight

Bottom line of patient prep for IVU

colon free of gas and fecal material

Nephrogram phase

15-30 seconds post injection referred to as 1 minute image demonstrating opacification of renal parenchyma

Phases of Excretion Urography

nephrogram, pyelogram, post release/spill

Pyelogram Phase

opacification of renal collecting system; 2-8 min post contrast injection and reaches bladder 15-20 min

Methods to enhance pelvicalcyeal filling

compression device and 15 degree trendelenburg

Main purpose of pyelogram phase

slow flow of urine to the bladder to ensure adequate filling of renal pelvis and calyces

Post-Release/Spill Image

demonstrates contrast filled distal ureters to assess asymmetrical renal function

AP Coned Image (IVU)

taken immediately after injection; early stages of contrast in parenchyma and entering the collecting system

Images acquired in IVU

AP coned, AP full abdo, 30 posterior oblique full abdo

30 degree posterior oblique full abdo image

kidney of elevated side best demonstrated and downside ureter projected away from the spine

Lateral IVU image best demonstrates:

pressure displacement of kidney = tumours

Ap axial bladder IVU image best demonstrates

bladder filling with contrast and distal ureters if pt has reflux

delayed IVU image best demonstrates

level of obstruction

post void IVU image best demonstrates

assess bladder emptying and BPH

erect IVU image best demonstrates

filling of distal ureter and bladder

Pediatric IVU Consideration

carbonated drinks to use gas as a negative contrast agent

Ultrasound Role in Imaging Urinary Systems

excellent for imaging renal parenchyma not great for collection system

CT Role in imaging Urinary System

excellent detail - GOLD STANDARD