V/Q Spect is strongly recomended as it allows the diagnosis of Pulmonary embolism to be made with accuracy even in the presence of diseases such as COPD and pneumonia. The basic principle for the diagnosis of PE based upon V/PSCAN is to recognize lung segments or subsegments without perfusion but preserved ventilation, i.e. mismatch. V/Q SPECT has higher sensitivity and specificity than PLANAR V/Q.

            In a recent publication Gutte1 Henrik et al. concluded that V/Q SPECT in combination with low-dose CT without contrast enhancement has an excellent diagnostic performance and should therefore probably be considered first-line imaging in the workup of PE in most cases. V/Q SPECT had a sensitivity of 97% and a specificity of 88%. When low-dose CT was added, the sensitivity was still 97% and the specificity increased to 100% (3).

2)  Bajc M et al. EANM Guidelines for ventilation/perfusion scintigraphy. Part 1. Pulmonary imaging with ventilation/perfusion single photon emision tomography. Eur J Med Mol Imaging 2009; 36:1356-1370.

3)   Gutte1 Henrik et al. Detection of Pulmonary Embolism with Combined Ventilation–Perfusion SPECT and Low-Dose CT: Head-to-Head Comparison with Multidetector CT Angiography. J Nucl Med 2009; 50:1987–1992.