Initial clinical experience with dedicated ultra fast solid state cardiac gamma camera

Full text: To analyze the imaging and diagnostic performance of new dedicated ultra fast solid state detector gamma camera and compare it with standard dual detector gamma camera in myocardial perfusion imaging. Material and Methods: In total 900 patients underwent myocardial perfusion imaging between 1st February 2010 and 29th August 2010 either stress/rest or rest/stress protocol. There was no age or gender bias (there were 630 males and 270 females). 5 and 15 mCi of 99mTc - Tetrofosmin/MIBI was injected for 1st and 2nd part of the study respectively. Waiting period after injection was 20 min for regular stress and 40 min for pharmacological stress and 40 min after rest injection. Acquisition was performed on solid state detector gamma camera for a duration of 5 min and 3 min for 1st and 2nd part respectively. Interpretation of myocardial perfusion was done and QGS/QPS protocol was used for EF analysis. Out of these, 20 random patients underwent back to back myocardial perfusion SPECT imaging on standard dual detector gamma camera on same day. There was no age or gender bias (there were 9 males, 11 females). Acquisition time was 20 min for each part of the study. Interpretation was done using Autocard and EF analyses with 4 DM SPECT. Images obtained were then compared with those of solid state detector gamma camera. Result: Good quality and high count myocardial perfusion images were obtained with lesser amount of tracer activity on solid state detector gamma camera. Obese patients also showed good quality images with less tracer activity. As compared to conventional dual detector gamma camera images were brighter and showed better contrast with solid state gamma camera. Right ventricular imaging was better seen. Analyses of diastolic dysfunction was possible with 16 frame gated studies with solid state gamma camera. Shorter acquisition time with comfortable position reduced possibility of patient motion. All cardiac views were obtained with no movement of the detector reducing camera related motion artifacts. Diagnostic performance was comparable to that of standard dual detector gamma camera images. Mid septum invariably showed perfusion defects in QPS protocol, this probably was due to lack of normal database for solid state detector. Lung activity could not be visualized due to small field of view. Extra cardiac activity could be assessed. CONCLUSION: We preferred solid state cardiac gamma camera over conventional dual detector gamma camera for myocardial perfusion imaging. Advantages of solid state gamma camera over standard dual head gamma camera: 1. Faster acquisition time 2. Increased patient comfort 3. Less radiation dose to the patient 4. Brighter images 5. No motion artifact 6. Better right ventricular imaging Disadvantages 1. Extra cardiac activity cannot be assessed 2. Lung activity not seen due to small field of view 3. Invariably septal perfusion defects noted