Noninvasive diagnostic methods | Advantages | Disadvantages |
---|---|---|
- 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 | ||
- 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) | ||
- 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 | |
- 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 |