Contemporary SPECT/CT V/Q scanning: protocols, pearls and pitfalls

Area of Science:

• Nuclear Medicine
• Radiology
• Pulmonary Medicine

Background:

• Lung scintigraphy has been a cornerstone in pulmonary diagnostics for over six decades.
• Technological advancements have transformed it into a tomographic modality, utilizing SPECT/CT for improved imaging.
• Modern lung scanning assesses ventilation (V) and perfusion (Q) with technetium-99m radiolabeled agents.

Purpose of the Study:

• To highlight the evolution of lung scintigraphy into a sophisticated diagnostic tool.
• To emphasize the role of SPECT/CT in improving the accuracy of pulmonary embolism (PE) diagnosis.
• To discuss the expanded applications of lung scanning beyond PE detection, including functional assessment and surgical guidance.

Main Methods:

• Utilizing SPECT imaging for both ventilation and perfusion assessment.
• Integrating low-dose CT with SPECT for anatomical correlation.
• Employing technetium-99m radiolabeled agents for V/Q imaging.

Main Results:

• SPECT/CT enhances the sensitivity and specificity of lung scanning for PE.
• Lung scanning now assesses regional lung function and V/Q matching for gas exchange.
• Diagnostic accuracy for PE exceeds 95% with minimal indeterminate reports.

Conclusions:

• Lung scintigraphy, particularly SPECT/CT, remains a highly effective diagnostic tool for pulmonary embolism.
• The modality's utility extends to evaluating regional lung function and guiding interventions.
• Despite challenges like artifacts, experienced interpretation yields high diagnostic confidence.