[A newly developed maneuver, field change conversion (FCC), improved evaluation of the left ventricular volume more accurately on quantitative gated SPECT (QGS) analysis].

PURPOSE To investigate whether a newly developed maneuver that reduces the reconstruction area by a half more accurately evaluates left ventricular (LV) volume on quantitative gated SPECT (QGS) analysis. METHODS The subjects were 38 patients who underwent left ventricular angiography (LVG) followed by G-SPECT within 2 weeks. Acquisition was performed with a general purpose collimator and a 64 x 64 matrix. On QGS analysis, the field magnification was 34 cm in original image (Original: ORI), and furthermore it was changed from 34 cm to 17 cm to enlarge the re-constructed image (Field Change Conversion: FCC). End-diastolic volume (EDV) and end-systolic volume (ESV) of the left ventricle were also obtained using LVG. RESULTS EDV was 71 +/- 19 ml, 83 +/- 20 ml and 98 +/- 23 ml for ORI, FCC and LVG, respectively (p < 0.001: ORI versus LVG, p < 0.001: ORI versus FCC, p < 0.001: FCC versus LVG). ESV was 28 +/- 12 ml, 34 +/- 13 ml and 41 +/- 14 ml for ORI, FCC and LVG, respectively (p < 0.001: ORI versus LVG, p < 0.001: ORI versus FCC, p < 0.001: FCC versus LVG). CONCLUSION FCC was better than ORI for calculating LV volume in clinical cases. Furthermore, FCC is a useful method for accurately measuring the LV volume on QGS analysis.