Abstract
Background
A new low-energy high-resolution-sensitivity (LEHRS) collimator was developed by General Electric Healthcare. SwiftScan planar and SPECT system using LEHRS collimator were formulated to achieve the low-dose and/or short-term acquisition. We demonstrated the performance of SwiftScan planar and SPECT system with LEHRS collimator using phantoms.
Methods
Line source, cylindrical and flat plastic dish phantoms were used to evaluate the performance of planar and SPECT images for four patterns of Siemens LEHR, GE LEHR, GE LEHRS and SwiftScan using two SPECT-CT scanners. Each phantom was filled with 99mTc solution, and the spatial resolution, sensitivity and image uniformity were calculated from the planar and SPECT data.
Results
The full-width at half maximum (FWHM) values as system spatial resolution of Siemens LEHR, GE LEHR and GE LEHRS were 7.3, 7.5 and 7.3 mm, respectively. GE LEHRS showed the lower FWHM value by increasing the blend ratio in Clarity 2D processing. The system sensitivities of Siemens LEHR, GE LEHR and GE LEHRS were 88.4, 67.6 and 89.8 cps/MBq, respectively. The system sensitivity of GE LEHRS increased by approximately 30% compared with that of GE LEHR and was similar to that of Siemens LEHR. The FWHM values of SPECT with an FBP method were 10.3, 10.4, 10.4 and 10.3 mm (p = n.s.). The FWHM values of the OSEM method were better with an increase in iteration values. The differential uniformities of Siemens LEHR, GE LEHR, GE LEHRS and GE SwiftScan were 15.3%, 15.1%, 15.4% and 14.6%, respectively, using the FBP method. The differential uniformity of OSEM method was higher with an increase in iteration value.
Conclusion
The SwiftScan planar and SPECT have a high sensitivity while maintaining the spatial resolution compared with the conventional system.