Easy Method of Patient Positioning for Convergent-Beam Cardiac SPECT

The use of convergent-beam SPECT can increase detection sensitivity; however, the projection data are likely to be truncated if the patient is not properly positioned. This article describes a patient-positioning method that has been adopted in our hospital for cardiac SPECT scans when convergent-beam collimators are used. Methods: The system that we use has 3 detector heads and a patient table (i.e., bed) with 3 locking positions: left, center, and right. When convergent-beam collimators are used in a cardiac SPECT scan, the patient table is locked in the left position, and a noncircular contour orbit is set up. Results: We were able to acquire truncation-free cardiac projections for all of our patients. Conclusion: Patient positioning in convergent-beam SPECT is important. If the patient is not positioned properly, then the heart may be truncated in some projection views. The use of the left locking position of the patient table positions the heart at the center of rotation, and the heart is not truncated in the projection data.