V/Q Scanning Using SPECT and SPECT/CT

TLDR

Ventilation‑perfusion (V/Q) scanning is routinely used to diagnose pulmonary embolism, but planar imaging has known limitations that SPECT overcomes by providing 3‑dimensional data, enabling novel parametric analyses and broader applications to other pulmonary conditions. Any nuclear medicine department equipped with a modern hybrid scanner can now perform combined V/Q SPECT with CT (using low‑dose protocols) to further enhance diagnostic accuracy. V/Q SPECT demonstrates superior diagnostic performance over planar imaging, showing higher sensitivity, specificity, accuracy, and a lower indeterminate rate, and when compared to CT pulmonary angiography, it offers higher sensitivity, lower radiation dose, fewer suboptimal studies, and no contrast‑related complications.

Abstract

Planar ventilation-perfusion (V/Q) scanning is often used to investigate pulmonary embolism; however, it has well-recognized limitations. SPECT overcomes many of these through its ability to generate 3-dimensional imaging data. V/Q SPECT has higher sensitivity, specificity, and accuracy than planar imaging and a lower indeterminate rate. SPECT allows for new ways to display and analyze data, such as parametric V/Q ratio images. Compared with CT pulmonary angiography, SPECT has higher sensitivity, a lower radiation dose, fewer technically suboptimal studies, and no contrast-related complications. Any nuclear medicine department equipped with a modern hybrid scanner can now perform combined V/Q SPECT with CT (using low-dose protocols) to further enhance diagnostic accuracy. V/Q SPECT (with or without CT) has application in other pulmonary conditions and in research.