|
Doppler sonography[18, 27, 30–32, 34, 78–101]
|
- noninvasive
|
- no standardized guidelines
|
|
- without ionizing radiation
|
- operator dependent
|
|
- less expensive
|
- time consuming (60 to 120 minutes)
|
|
- high resolution
|
- blinding procedures are challenging
|
|
- real time information
|
- cannot perform global view of the veins (limited window)
|
|
- sensitive to detect flow changes, intra- and extra-luminal abnormalities
|
- misidentification of the veins
|
|
- ability to measure velocity
|
- influenced by hydration status
|
|
- possible control of respiratory phases
| |
|
Magnetic resonance venography[10, 30, 31, 34, 42, 43, 102]
|
- noninvasive
|
- no real time information
|
|
- without ionizing radiation
|
- cannot detect intra-luminal abnormalities
|
|
- well established method
|
- low specificity of conventional MRV techniques
|
|
- operator independent
|
- influenced by hydration status
|
|
- less time consuming than DS
|
- azygos vein examination needs technical improvements due to important artifacts (breathing, heart movements)
|
|
- provide global view of intra- and extra-cranial venous system
|
- underestimates the vascular caliber
|
|
- easy to blind
|
- “snapshot” nature
|
|
- ability to measure flow and velocity with advanced technique (phase contrast MRV)
| |
|
- global view of collateral veins
|
|
- can be performed without contrast (pregnancy, allergy)
|
|
Computed tomography venography[5, 103, 104]
|
- noninvasive
|
- ionizing radiation
|
|
- less expensive and time consuming than MRV
|
- no real time information
|
|
- better spatial resolution than MRV
|
- cannot detect intra-luminal abnormalities
|
|
- global view of veins
|
- cannot be performed without contrast (allergy, toxicity)
|
|
- lack of experience for extra-cranial venous system
|
- less contrast resolution than MRV
|
|
Plethysmography[105, 106]
|
- noninvasive
|
- higher false-positive rate due to venous compression arising from incorrect patient positioning or the action of extrinsic masses
|
|
- provides valuable information regarding the impact of reflux and obstruction on overall venous function
|
- low resolution
|
| |
- can monitor the dynamics of venous disease over time and evaluation of treatment outcomes
| |
