TY - JOUR T1 - Clinical Comparison of Circular versus Noncircular Acquisition Using Technetium-99m Myocardial Perfusion SPECT Imaging JF - Journal of Nuclear Medicine Technology JO - J. Nucl. Med. Technol. SP - 37 LP - 40 VL - 25 IS - 1 AU - Michael P. White AU - April Russell AU - Victor A. Mascitelli AU - Robert S. Morris AU - Adel R. Shehata AU - Gary V. Heller Y1 - 1997/03/01 UR - http://tech.snmjournals.org/content/25/1/37.abstract N2 - The optimal orbit for myocardial SPECT imaging has not yet been determined. In order to evaluate differences in image quality and reader interpretation between orbiting methods, 50 patients scheduled for routine stress/rest 99mTc-sestamibi imaging had both a circular and a noncircular study using an ADAC Vertex dual-head imaging system. Methods: Each study was acquired using a 64 × 64 matrix, 64 stops at 25 sec per stop. Images were processed using a Butterworth filter with a frequency cutoff of 0.6 and an order of 5.0. Studies were interpreted by three experienced readers without knowledge of patient name or orbiting technique for normal and abnormal segments and overall image quality. Results: There was no significant difference in the semiquantitative assessment of either defect extent or reversibility or in the quantitative assessment of defect size between the two types of orbits. However, while all 50 non circular studies were read as good or fair quality, 23 circular studies were read as fair or poor (p = < 0.0002). Conclusion: Qualitative and quantitative analysis revealed similar size and extent of perfusion defects using either circular or noncircular orbit, but images with the noncircular orbit were of significantly better image quality and may be preferable to a circular orbit with 99mTc-sestamibi. ER -