OBJECTIVES: (123)I is becoming an important radionuclide for cardiac imaging. Multiple, low-abundance, high-energy photons associated with (123)I imaging can cause septal penetration in the collimators and degrade quantification of the (123)I cardiac uptake. This study presents a method for the deconvolution of septal penetration (DSP) for improving quantification in (123)I cardiac single photon emission computed tomography (SPECT). METHODS: Distance-dependent point spread functions were measured for low-energy high-resolution collimators on a dual-head SPECT system. The measured point spread functions were used in two-dimensional (2-D) and three-dimensional (3-D) models of the collimator response, respectively. 2-D DSP and 3-D DSP were then developed and implemented using iterative reconstruction. A cardiac torso phantom with an internal calibration source was designed with various heart-to-calibration ratios (HCRs) simulating different levels of a patient's uptake. SPECT acquisitions of the phantom were performed using optimized acquisition and processing parameters for (123)I cardiac SPECT. HCRs were calculated using planar projection and tomographic reconstructions. The paired t-test and regression analysis were used to compare the HCRs given by different calculation methods. RESULTS: SPECT produced more accurate HCRs than planar imaging. The slopes of the regression lines for SPECT using filtered back-projection were statistically significantly higher than those for planar imaging (0.2118 +/- 0.0297 vs. 0.0819 +/- 0.0070, P = 0.0001). 2-D DSP and 3-D DSP yielded similar HCRs that were close to the true HCR. The slopes of the regression lines for 2-D DSP and 3-D DSP were 0.9203 +/- 0.0523 and 0.9101 +/- 0.0304, respectively. The DSP HCRs were significantly more accurate than those calculated without DSP (P < 0.0001). CONCLUSION: DSP significantly improves quantification in (123)I cardiac SPECT imaging. 2-D DSP with its less computational burden shows promise for implementation in clinical practice so as to allow the use of the widely available low-energy, high-resolution collimators for quantitative I cardiac SPECT imaging.
OBJECTIVES: (123)I is becoming an important radionuclide for cardiac imaging. Multiple, low-abundance, high-energy photons associated with (123)I imaging can cause septal penetration in the collimators and degrade quantification of the (123)I cardiac uptake. This study presents a method for the deconvolution of septal penetration (DSP) for improving quantification in (123)I cardiac single photon emission computed tomography (SPECT). METHODS: Distance-dependent point spread functions were measured for low-energy high-resolution collimators on a dual-head SPECT system. The measured point spread functions were used in two-dimensional (2-D) and three-dimensional (3-D) models of the collimator response, respectively. 2-D DSP and 3-D DSP were then developed and implemented using iterative reconstruction. A cardiac torso phantom with an internal calibration source was designed with various heart-to-calibration ratios (HCRs) simulating different levels of a patient's uptake. SPECT acquisitions of the phantom were performed using optimized acquisition and processing parameters for (123)I cardiac SPECT. HCRs were calculated using planar projection and tomographic reconstructions. The paired t-test and regression analysis were used to compare the HCRs given by different calculation methods. RESULTS: SPECT produced more accurate HCRs than planar imaging. The slopes of the regression lines for SPECT using filtered back-projection were statistically significantly higher than those for planar imaging (0.2118 +/- 0.0297 vs. 0.0819 +/- 0.0070, P = 0.0001). 2-D DSP and 3-D DSP yielded similar HCRs that were close to the true HCR. The slopes of the regression lines for 2-D DSP and 3-D DSP were 0.9203 +/- 0.0523 and 0.9101 +/- 0.0304, respectively. The DSP HCRs were significantly more accurate than those calculated without DSP (P < 0.0001). CONCLUSION: DSP significantly improves quantification in (123)I cardiac SPECT imaging. 2-D DSP with its less computational burden shows promise for implementation in clinical practice so as to allow the use of the widely available low-energy, high-resolution collimators for quantitative I cardiac SPECT imaging.
Authors: Ji Chen; Russell D Folks; Liudmila Verdes; Daya N Manatunga; Arnold F Jacobson; Ernest V Garcia Journal: J Nucl Cardiol Date: 2011-12-07 Impact factor: 5.952
Authors: Milena J Henzlova; W Lane Duvall; Andrew J Einstein; Mark I Travin; Hein J Verberne Journal: J Nucl Cardiol Date: 2016-06 Impact factor: 5.952
Authors: Ian P Clements; Ernest V Garcia; Ji Chen; Russell D Folks; Javed Butler; Arnold F Jacobson Journal: J Nucl Cardiol Date: 2015-03-19 Impact factor: 5.952
Authors: Hein J Verberne; G Aernout Somsen; Pavol Povinec; Berthe L F van Eck-Smit; Arnold F Jacobson Journal: Eur J Nucl Med Mol Imaging Date: 2009-03-04 Impact factor: 9.236