Transcript 1530_Rosenblatt_EB4F1x

ACP Annual Congress 2016
Mel Rosenblatt, M.D. FACPh
Connecticut Image Guided Surgery
Disclosures
I have no pertinent disclosures related to
the material that will be presented
Venography
Introduction
• Venography is the oldest venous imaging tool
• Newer non invasive imaging modalities have supplanted venography
as a diagnostic tool
• CT/CTV (direct or indirect)
• MRI/MRV
• IVUS
• Despite it’s age venograpjy still has value and basic interpretation skills
are neccessary
• In the modern age what is the role of venography?
Venography
What is it’s Role?
• Diagnostic
• Venography is rarely used as a diagnostic tool alone
• Can be used to diagnosis DVT when other tests are
negative i.e. Calf vein DVT
• Diagnostic CO2 venography may be use in patients who
can not have IV contrast
• Adjunct to intervention
• Confirms extent of occlusive disease
• Monitors progress of treatment during venous lysis
• IVUS may be more sensitive, but venography is still
needed for stent placement
• Defines extent and volume of VMs at time of embolization
Venography
Interpretation
• X-Ray imaging is dependent on the attenuation
difference between different types of tissue
• Blood vessels can not be distinguished from soft
tissue due to small attenuation differences
• Intraluminal pathology often has similar attenuation to
the blood vessels itself
• A Contrast agent is needed to distinguish objects
within the lumen of a vessel and to distinguish the
vessel from adjacent soft tissue
Venography
Interpretation
• The quality of imaging depends on the degree of
tissue contrast at the time the picture is taken
• Contrast “strength”
• Contrast timing
• Intraluminal pathology such as thrombus will appear
as areas where contrast can not go (filling defects)
• Morphologic abnormalities will appear as aberrant
anatomy or enlarged lumens
• Aneurysms
• Venous Malformations
Venography
Technique for LE Thrombus
• A superficial vein is cannulated on the medial aspect
of the foot adjacent to the great toe
• Contrast is injected and images are obtained
beginning in the foot
• Tourniquets are applied to force contrast into the deep
venous system
• More than 150 ml of 30% contrast is needed to
adequately visualizes the LE veins
• Contrast dilution results in poor iliac vein opacification
• Occluded vein will not fill with contrast which does not
confirm a DVT
Venography
LE DVT
Venography
Digital Subtraction Technique
• Digital imaging with or without subtraction has replaced plain film
imaging
• Advantages
• Rapid acquisition
• Better discrimination of contrast filled structures
• Disadvantages
• Decreased resolution
• Subtraction artifacts due to motion
• Low dynamic range (“burn out” artifact or “glare”)
• New flat panel detectors have a higher dynamic range reducing this effect
Venography
DSA Technique
• Subtraction
technique improves
visualization of
thrombus in vein
• Catheter markers
are easier to see in
the non-subtracted
image
Venography
DSA Technique
Glare artifact prevents visualization
of peripheral PA branches
Reduced resolution of
peripheral branches
Venography
Carbon Dioxide Contrast
• CO2 gas can be used as a
contrast medium for
performing venography
• Contrast allergy
• Renal dysfunction
• CO2 delivery systems are
not standardized
• Imaging resolution is limited
• Complication have been
reported
Venography
Iliac Vein Obstruction
• The use of venography alone for the detection of
iliac vein compression syndrome is problematic
• Compared to IVUS single plane venography had poor
sensitivity (45%) and negative predictive value (49%)
in the detection of an obstruction of greater than 70%
(P Neglén et. al. 2002)
• VIDIO trial (2014-2015)
• Compared IVUS to multiplanar venography
• IVUS detected 88% more lesions
• Venography missed lesion in 29% of patients
Venography
Iliac Vein Obstruction: Technique
•
•
•
•
Contrast should be injected in the iliac vein
Steep oblique views help to visualize narrowing
Valsalva maneuver can accentuate lesion
Venographic findings
• Effacement
• Filling of collaterals
• Retrograde filling of internal iliac vein
• Venography can provide some information on the
physiologic impact of the lesion
• Venography is needed for treatment
Venography
Iliac Vein Obstruction
Venography
Iliac Vein Obstruction
50 Y.O man
Supine venogram
45 Y.O Woman with left leg swelling
Supine venogram
Valsalva
Venography
Iliac Vein Obstruction
Cross pelvic
collateral
Venography
Direct Venography
• Traditional venography rarely fills focal lesions
• Direct venography (varicography) of focal complex venous pathology is
essential for treatment
• Defines extent and lesion volume
• Distinguishes between normal and abnormal venous structures
• Determines effectiveness of treatment
• Technique
• Ultrasound is used to guide needle access into lesion
• Contrast is injected under direct fluoroscopy to fill the lesion
Direct Venography
Venous Malformations
Direct Venography
Pelvic Veins
Venography
Conclusion
• As a diagnostic tool, venography has been supplanted by cross
sectional imaging modalities
• Venography is an essential imaging tool to guide interventions
• Iliac occlusive disease is better evaluated with IVUS but venography is
still needed to treat
• In the setting of complex venous anomalies direct venography
(varicography) is able to define vascular anatomy better than cross
sectional imaging
• Direct venography is essential for treatment of complex venous lesions