Is Scintigraphy the Same as a VQ Scan?
A VQ scan is a specific type of scintigraphy—scintigraphy is the broader imaging technique, while a VQ (ventilation-perfusion) scan is a particular application of scintigraphy used to evaluate lung ventilation and blood flow. 1
Understanding the Relationship
Scintigraphy is the general term for nuclear medicine imaging that uses radioactive tracers to visualize organ function. 1
VQ scanning is a specific scintigraphic procedure that:
- Uses intravenous injection of technetium (Tc)-99m-labeled macroaggregated albumin particles to assess lung perfusion 1
- Combines this with ventilation studies using tracers such as xenon-133 gas, Tc-99m-labeled aerosols, or Tc-99m-labeled carbon microparticles (Technegas) 1
- Is formally called "ventilation-perfusion scintigraphy" 1
Clinical Context
The terms are often used interchangeably in pulmonary medicine because:
- VQ scanning is the most common application of lung scintigraphy 2
- When clinicians refer to "lung scintigraphy," they typically mean VQ scanning 1
- The European Society of Cardiology guidelines specifically use both terms synonymously when discussing pulmonary embolism diagnosis 1
Modern Variations
VQ scintigraphy now includes advanced techniques:
- Planar VQ scanning: Traditional two-dimensional imaging 1
- VQ SPECT (single-photon emission CT): Three-dimensional imaging with 94% accuracy 1, 3
- VQ SPECT/CT: Combines functional and anatomical imaging 1, 3
All of these are forms of scintigraphy applied specifically to lung ventilation and perfusion assessment. 4, 3