Objectives: Soft tissue attenuation artifacts are the most common cause of false-positives
in myocardial perfusion SPECT (MPS). Few studies assessing the value of prone imaging in women
have been published. Our study evaluated the impact of prone position imaging on the interpretation
of MPS scans of women with suspect coronary artery disease (CAD) and also defined the relationship
between breast attenuation, age, bra cup size and body mass index (BMI).
Methods: MPS scans of women with suspected CAD (n=431) were retrospectively analyzed by two
blinded experts not aware if post-stress images were acquired in supine or prone position. After
semi-quantitative analysis summed stress, rest and difference scores (SSS, SRS and SDS, respectively)
were calculated and scans were classified as normal, abnormal or equivocal.
Results: The SSS and SDS values were distinct and lower for images in prone position (p < 0.01).
The analysis of the 17 segments of the left ventricle showed similar findings for most of the anterior
(p < 0.01) and inferior (p<0.01) wall segments .One hundred forty-five studies were considered
equivocal by the observers, but after the combined analysis with prone images, 70 (48.3%) were reclassified
to normal (p < 0.01).
Conclusions: Prone position imaging had impact on the interpretation of MPS images. The influence
of soft tissue attenuation was reduced and studies initially classified as equivocal were reclassified to