title: Attenuation correction of myocardial perfusion SPET in patients of normal body mass index.
abstract: Soft tissue attenuation artefacts are more likely to occur in patients with high body mass  index (BMI) undergoing myocardial perfusion imaging (MPI) and therefore it is routine practice in our  department to perform attenuation correction in this group of patients. However, we suspected that attenuation  artefacts may also occur in patients with normal BMI. We collected data prospectively on 57 patients with BMI  less than 25kg/m(2) who underwent stress-rest MPI single photon emission tomography (SPET) as part of their standard  management at our institution. The differences between the attenuation corrected (AC) and non attenuation  corrected (NC) images were evaluated by two experienced readers blinded to patient gender and clinical details.  Visual improvement in perfusion with attenuation correction was seen in 54.4% of patients with normal BMI and  was more common in males (84.2%) than females (39.5%). Discordances between AC and NC were most  frequent in the inferior, inferolateral and anteroseptal segments in both males and females and were also seen  in the apical and anterior segments in some patients, mainly in females, in keeping with the well-recognized  distribution pattern for attenuation artefacts. In conclusion, although a small sample size was used in this  study, changes in appearance with attenuation correction likely to represent attenuation artefacts were seen  in 54.4% of patients with normal BMI and were two times more common in males than females. These changes  were felt to be clinically relevant in that they could lead to a change in the final report and may ultimately affect the  diagnosis and clinical management. Thus, attenuation correction could be of value in patients of normal BMI.  Further larger studies with correlation with clinical follow-up or invasive coronary angiography are warranted.
authors.affiliation: Nuclear Medicine Centre, Manchester Royal Infirmary, Central Manchester University Hospitals, Oxford Rd, M13 9WL, Manchester, United Kingdom. mshawgi@gmail.com
authors.forename: Mohamed
authors.initials: M
authors.lastname: Shawgi
authors.forename: Christine M
authors.initials: CM
authors.lastname: Tonge
authors.forename: Richard S
authors.initials: RS
authors.lastname: Lawson
authors.forename: Sivakumar
authors.initials: S
authors.lastname: Muthu
authors.forename: Jacqueline
authors.initials: J
authors.lastname: James
authors.forename: Parthiban
authors.initials: P
authors.lastname: Arumugam
mesh_terms: D000465:Algorithms; D015992:Body Mass Index; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*