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Home > GE Community > NM/PET > Cardiac Case Studies Printer Friendly Hawkeye - Xeleris Hawkeye - Xeleris eFlexTrial Cardiac Patient History This 68 year old male was referred for myocardial perfusion imaging 3 months status post revascularization of the right coronary artery for evaluation of patency. Some atypical chest pain was noted. Imaging Procedure The one day Sestamibi protocol was used, and rest imaging was performed first. Imaging was done on a  GE Hawkeye Dual Head Camera  with 60 stops over 180 degrees. Acquisition Parameters:   Type of Acquisition Time per stop Agent Dose Rest Ungated SPECT / CT 20 seconds 99m Tc Sestamibi 15 mCi Stress Gated SPECT / CT 25 seconds 99m Tc Sestamibi 30 mCi Target heart rate (85% of maximum heart rate): 129 Maximal heart rate achieved on treadmill: 90% Imaging Analysis Data was processed in MyovationTM, the cardiac analysis protocol on Xeleris. The quality control checks provided in MyovationTM show the acquisition to be of good quality. The stress maximum pixel value was 201; rest maximal pixel value was 65. The guideline for an adequate count study for 60-64 projection images is to have a maximum pixel value of at least 50 counts within a tight circular/ elliptical ROI around the epicardial edge of the myocardium on an anterior view. The stress selective linogram shows no significant motion in the vertical direction and shows that there is no significant extra- cardiac activity. The stress sinogram shows no significant motion in the horizontal direction.                  Figure 1: Stress selective linogram                   Figure 2: Stress sinogram Volumetrix, the fusion protocol on Xeleris, provides fused CT-SPECT images to check for acquisition quality control.                      Figure 3: SPECT-CT Transaxial                      Figure 4: SPECT-CT sagittal The rotating projection images show a patient with a large mid-section which can cause increased attenuation of the inferior wall. Attenuation artifacts are often mistaken for perfusion defects leading to false positive interpretation. Hawkeye cardiac attenuation correction, however, is consistent over a full range of body types.               Figure 5: Stress projection images                 Figure 6: Rest projection images Reconstruction and reformatting of the slices was done in MyovationTM. Though the primary reconstruction was filtered back projection, selecting the Comparison Review option in MyovationTM conveniently shows the stress and rest FBP and IR-AC slices on the same display for easy comparison. Count deficiencies in the inferior walls of both the rest and stress FBP slices have been noticeably improved in the IR-AC slices, correcting for inferior wall attenuation. FBP IR-AC   Figure 7: Stress SA slices   Figure 8: Rest SA slices FBP IR-AC   Figure 9: Stress VLA slices   Figure 10: Rest VLA slices       Figure 11: Stress attenuation map   Figure 12: Rest attenuation map EKG Results Non-specific ECG changes were noted with no ST depression at maximal exertion. Test terminated at maximal heart rate and SOB. No chest pain was noted. Findings FBP images were interpreted as inferior wall scar with possible ischemic component. This could also be a diaphragmatic attenuation artifact. With Hawkeye AC the inferior wall is shown to be viable with no ischemia. The validity of the revascularization of the RCA is confirmed. Images Courtesy of: VA Medical Center Baltimore, Maryland

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