Download 8 Ornan MRI of the genitourinary tract VU CME

Afshan A. Ornan, MD
Medical Director of MRI, Virginia Urology
[email protected]
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Main differences between MRI and CT
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Contrast update
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Basic MR sequences
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Utility of MRI in genitourinary tract imaging
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Renal
Prostate
Urethra
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No radiation
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Smaller field of view
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We can build protocols to answer specific
questions
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Screening process for foreign bodies
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Contrast agents are different
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Gadolinium bound by chelating agent
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Nephrogenic systemic fibrosis (NSF)
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CT contrast: Iodine based
Fibrosis of skin, joints, eyes, and internal organs as a
result of dechelation
Renal failure is a risk factor, not a result
Nearly all affected patients were acutely ill: sepsis,
multisystem organ failure.
Controversy over “Gadolinium Deposition
Disease”
Be cautious with an eGFR < 30
Water
Dark
Bright
Hemorrhage
Bright
Dark
Contrast
Bright
Dark
Fat
Bright
Bright
Tumor
Varies
Varies
T1
T2
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Cystic and hemorrhagic lesions
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Differentiate between subtypes of RCCs
Local staging of RCC
Evaluation of distant metastases  CT
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Excellent characterization with MR
Following indeterminate cystic lesions (no radiation)
Surveillance for local recurrence after partial
nephrectomy or ablation
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Better at distinguishing fibrosis and hemorrhage
from tumor
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With the advent of diffusion sequence:
Tumor localization
 Tumor grading
 Local staging
 Pelvic adenopathy to the bifurcation
 Recurrence
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MR guided biopsies and ablations
Structured reporting: PI-RADS
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Pre biopsy imaging to ensure sampling of the most
suspicious area
Determining proximity to neurovascular bundle
Active surveillance, especially if the patient is a poor biopsy
candidate
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Elevated PSA, negative or discordant biopsies
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Recurrence
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Endorectal coil
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Peripheral zone: T2 bright
Transitional zone:
heterogeneous
Prostate capsule: T2 dark
Neurovascular bundles : T2
dark
T2
Path results:
“PROSTATE, MRI
LESION, BIOPSY:
ADENOCARCOMA,
GLEASON SCORE
4+5=9/10,
INVOLVING 4 OF 4
CORES,
APPROXIMATELY
60% OF CROSSSECTIONAL
AREA.”
T2
Post contrast subtraction
T2
ADC
Gleason 8
T2
ADC
T2
Post contrast subtraction
Gleason 7
in 4 out of 4
cores on
repeat
biopsy
T2
ADC
Enhancement curve: type 3
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Urethral diverticulum
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Urethral cancer
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Penile prosthesis
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Penile fracture
Diffusion
T2
Post contrast
T2
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Women’s health
Urethral diverticulum
 MR defecography to assess for pelvic organ prolapse
 Ovarian masses that need further characterization
 Uterine pathology
 Skene’s glands cysts, Gartner’s duct cysts
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Characterization of incidental findings on CT
and US
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Liver lesions
Pancreas
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Small adrenal nodules
Urinary tract stones
Urothelial tumor
Metastatic work up
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Exception:
contraindication to
CT contrast
Lung imaging
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MRI is a focused, longer, and versatile
examination.
Contrast agent is gadolinium based and does
not cause renal injury.
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Impaired renal function is a risk factor for NSF.
Utility of MRI of the genitourinary tract
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Impact on the management of prostate cancer
More definitive characterization of incidental
findings