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)
CT Urogram (CTU)
● CT without and then with contrast, with at least one set of images from the
excretory phase
● Higher yield than IVP
CT Urogram (CTU) Indications
● Evaluation of hematuria
● Identification of urothelial (bladder/ureter) tumors
Three scanning phases of CT Urogram (CTU)
● Noncontrast – Stone detection
● Nephrographic (90 seconds) – Eval kidneys for mass/lesions
● Delayed excretory (8-10 minutes) – Assess collecting system
CT Urogram is the gold standard for
____
characterization of renal masses
Indications for Magnetic Resonance Imaging (MRI)
● Demonstration of congenital anomalies
● Diagnosis of renal vein thrombosis
● Diagnosis and staging of renal cell carcinoma
● MR/Ultrasound fusion prostate guided biopsy
MR/Ultrasound fusion prostate guided biopsy
○ Fewer Bx (3-4 Bx instead of 12-15)
○ Find more significant cancers (30%)
○ Find fewer insignificant cases
MRI advantages and disadvantages
Advantages
● Direct imaging in any desired plane
● Excellent soft-tissue contrast
● No exposure to ionizing radiation
● Does not use iodinated contrast,
instead uses Gadolinium
Disadvantages
● Scanning time is relatively slow
● Image clarity is often inferior to CT
● Higher cost
Absolute Contraindications for MRI
● Intracranial aneurysm clips
● Intra-orbital metal fragments
● Many implants
Nephrogenic Systemic Fibrosis (NSF)
A form of contrast induced nephropathy precipitated by use of Gadolinium
○ If occurs, mostly in ESRD patients with GFR <30 mL/min
○ Progressive multiorgan fibrosing condition
○ Resemble skin diseases, such as scleroderma
Renal Angiography (Arteriogram)
Percutaneous needle puncture and catheterization into common femoral
artery → administration of contrast → plain film or fluoroscopy
○ Gold standard for direct visualization of renal vasculature
Gold standard for direct visualization of renal vasculature
Renal Angiography (Arteriogram)
Renal Angiography (Arteriogram) Indications
● Suspected renal artery stenosis/renal vein thrombosis
● Vascular malformations
● Pre-op mapping/tumor embolization to minimize blood loss
Magnetic Resonance Angiography (MRA) Indications
● Same as arteriogram with additions of evaluating renal transplant vessels,
○ Atherosclerosis within aorta and iliac arteries often visualized
Magnetic Resonance Angiography (MRA) advantages and disadvantages
Advantages
● Highly accurate/detailed in determining
number of renal arteries, size of kidneys,
and any anatomic anomalies
● No radiation
● Less invasive
Disadvantages
● Time intensive
● Gadolinium exposure
● Cost
Indications for CT angiogram
Same as MRA
● CTA is more commonly ordered if looking primarily at renal vasculature due
to faster image acquisition and technically easier to perform
Cystoscopy
A procedure where a thin, lighted cystoscope is inserted to visualize the lining
of the urethra and bladder. Often done in office.
Cystoscopy indications
● Evaluation of Pts with voiding symptoms
● Gross or microscopic hematuria
○ Gold Standard for diagnosing bladder cancer
■ Biopsy obtained during the procedure
● Evaluation of urethral or bladder diverticula
● Congenital abnormalities in pediatric patients
● Bladder hydrodistention
● Intraop evaluation after incontinence/prolapse procedure
Gold Standard for diagnosing bladder cancer
Cystoscopy
Cystoscopy contraindications
● Febrile patients with UTI
● Those with severe coagulopathy
Cystoscopy Therapeutic Indications
● Treatment of urethral strictures
● Bladder neck procedures
● Intravesical procedures
● Reflux treatment in peds
Advantages of flexible endoscopes:
less painful, able
to see entire bladder (incl. neck).
Advantages of rigid endoscopes:
more instrumentation options, better optics,
and more durable (use in OR)
Renal Biopsy
● A procedure to extract kidney tissue for laboratory analysis
● Usually performed as an outpatient procedure
● Used to identify various renal diseases, especially glomerular or interstitial
pathologies
Renal Biopsy indications
● Unexplained renal failure
● Acute nephritic syndrome
● Nephrotic syndrome (peds)
● Renal masses (primary or secondary)
● Renal transplant rejection
● Connective-tissue diseases
Percutaneous (or renal) needle biopsy
● Conscious sedation is used
● Local anesthetic is applied and small
incision made
● A needle is then inserted through the
incision into the kidney
● Typically U/S or CT the needle will be
guided to the area of concern
● Biopsy obtained
Open Biopsy
Typically done if history of bleeding or blood clots, or if only one kidney
● General anesthesia is given and a small
incision made
● A tissue sample is surgically removed
Collection of Urethral Swab specimen
Generally obtained when evaluating for an STI
Urinary Catheterization options
● Foley (indwelling)
● Suprapubic
● Intermittent/straight cath (in/out)
● External sheath (condom)
Urinary Catheterization indications
● Empty the bladder
● Measure urine production
● Obtain clean catch for urine culture
The single most important factor for preventing urinary catheter-related
complications is _____
limiting their use to appropriate indications
Indications for Urinary catheterization
● Urinary retention (with or without bladder outlet obstruction)
● Hourly urine output measurement (critically ill pts)
● Daily urine output for fluid management
● Intraoperatively to assess fluid status
● Immobilized patients
● Neurogenic bladder
● Incontinence – ONLY in patients with open wounds in perineal regions
Inappropriate reasons to catheterize
● Management of JUST urinary incontinence
● Monitor I’s and O’s in those who can spontaneously urinate
● PVR *
T/F Prophylactic antibiotic use is not recommended unless a proven UTI is present
T
Absolute contraindication to catheterization
● Presence of urethral injury (typically seen
with pelvic injury)
○ Blood at meatus or gross hematuria →
consult Urology
Urinary Catheterization complications
● Urethral dilatation
● Urethral irritation
○ Urethral ulceration
● Trauma
● Infection
○ Increases with BPH, bladder neck contracture, or urethral strictures
● “U-Turn”
Urinary Catheterization complications
● Inappropriate filling of the foley balloons
● False tracts
○ Urethral tears
○ Migration into the distal ureter
