Urological Diagnostics and Procedures Flashcards
Conventional Radiography usefulness
May demonstrate osseous abnormalities, abnormal calcifications, or large
soft-tissue masses, bowel gas pattern (Gas, Mass, Bones, and Stones)
○ Low sensitivity for stones and GU masses (rarely used as first line
imaging modality)
KUB (Kidney, Ureter, Bladder) advantages and disadvantages
● Advantages
○ Low cost and readily available
○ Less radiation than CT
■ Can use in pregnancy and peds
● Disadvantages
○ Limited visualization/soft tissue contrast
○ Radiation
IV Pyelography (IVP)
AKA – IV urography/excretory urography
● An IVP is performed by obtaining plain films
of the abdomen initially, then at timed
intervals after an IV injection of contrast
IV Pyelography (IVP) Indications
● Stones – medullary sponge kidney or renal
papillary necrosis
● Congenital anomalies of the urinary tract
● Surgery or scarring from surgery or frequent UTIs
● Pregnant Pts (with limited contrast)
IV Pyelography (IVP) advantages vs. disadvantages
Advantages
● Cheaper than CT
● Less radiation exposure compared to CT
Disadvantages
● Time consuming
● Utilizes contrast
Voiding Cystourethrography (VCUG)
Technique for visualizing the urethra and urinary bladder during micturition
Voiding Cystourethrography (VCUG) indications
Frequent UTIs (especially in children)
○ Ureteral reflux – most common etiology for
peds febrile UTIs
○ Suspected outflow obstruction
○ Bladder trauma or post-op evaluation
○ Urinary stress incontinence
Filling defects – ____
urethral strictures, urethral or bladder diverticulum,
false tracts
Vesicoureteral reflux
contrast moves retrograde into the ureter(s) and kidney(s)
Voiding Cystourethrography (VCUG) process
● The patient is catheterized and the bladder with radiocontrast
● The patient then voids
● Using fluoroscopy or standard X-ray, images are taken as the bladder
contracts
Post-Void Residual (PVR)
PVR measures the amount of urine left in the bladder after micturition
● The amount of residual urine can be measured by draining the bladder via catheterization or by using ultrasound
Post-Void Residual (PVR) Indications
Patients presenting with retention, incontinence, or incomplete emptying
○ Neurogenic bladder
■ Spinal cord injury, CVA, MS,
Parkinson’s disease
○ Urinary obstruction
○ Previous pelvic surgery/trauma
○ Medications
■ Sedatives, opiates, calcium channel
blockers
Interpretation of PVR urine volume
○ PVR < 50 cc is adequate bladder emptying
○ PVR < 100 cc is acceptable in patient over 65
○ PVR > 200 cc is incomplete bladder emptying
Higher risk of UTI with higher PVR
Renal/Bladder Ultrasound: what to assess
● Renal and testicular size (>2 cm difference is abnormal)
● Renal and testicular masses (solid vs cystic)
● Hydronephrosis (stones vs pregnancy)
● Doppler sonography (renal and spermatic vessels,
vascularity testicles, and renal masses)
● Bladder contour (mass, diverticulum, PVR)
○ Seen as round/oval
● Stones (brightly echogenic with shadowing)
Advantages vs. Disadvantages of Renal/bladder ultrasound
Advantages
● Ease of use
● High patient tolerance
● No need for contrast
● Lack of ionizing radiation
● Relative low cost
● Wide availability
Disadvantages
● Tissue nonspecificity
● Limited field of view
● Dependence on operator’s skill
● Dependence on patient’s body
habitus
Degrees of Hydronephrosis
● Grade 0 – no dilation (considered normal)
● Grade 4 – severe, gross dilation of
pelvis/calyces (ballooned effect)
● Grade 5 - most severe?
Simple or complex renal cysts on ultrasound:
Smooth, anechoic and with or without internal echoes; multiple in polycystic disease
CT Scan indications for kidneys
● Acute flank pain
● Hematuria
● Renal infection (abscess)
● Trauma
● Characterization and staging of renal
masses/neoplasms and polycystic kidney disease
○ Can detect small cysts down to 2-3 mm in diameter
○ Renal U/S used initially for screening
CT Scan other applications in the GU system
● Urinary bladder: Stage bladder tumors and diagnose bladder rupture following trauma
CT Scan
● Prostate: Detect lymphadenopathy, extraprostatic tumor extension
● Testes: Staging of testicular tumors
● Adrenal gland: Lesions can be characterized with delayed post-contrast images
CT Scan advantages vs. disadvantages
Advantages
● Quick
● Wide field of view
● Good spatial resolution
● Able to detect subtle differences in tissue
● Anatomical cross-sectional images
Disadvantages
● Low soft-tissue contrast resolution (but
better then U/S)
● Need for contrast media
○ Check BUN/Creatinine ratio and
eGFR with renal impairment
● Radiation exposure (10x more than plain
abdominal radiographs)
When to do CT with contrast
● All angiograms
● Any CT of the Abdomen or Pelvis looking at the organs
● Evaluation of renal and ureteral anatomy benefits greatly from administration of IV contrast
When to do CT without contrast
● Renal stones
● Patients with renal failure (and not on
dialysis)
● Post trauma with suspected bleed
Evaluation of stones requires a _____
noncontrast CT (Gold Standard)