A multicenter evaluation of a new post-processing method with depth-dependent collimator resolution applied to full-time and half-time acquisitions without and with simultaneously acquired attenuation correction
- 259 Downloads
The field of nuclear cardiology is limited by image quality and length of procedure. The use of depth-dependent resolution recovery algorithms in conjunction with iterative reconstruction holds promise to improve image quality and reduce acquisition time. This study compared the Astonish algorithm employing depth-dependent resolution recovery and iterative reconstruction to filtered backprojection (FBP) using both full-time (FTA) and half-time (HTA) data. Attenuation correction including scatter correction in conjunction with the Astonish algorithm was also evaluated.
We studied 187 consecutive patients (132 with cardiac catheterization and 55 with low likelihood for CAD) from three nuclear cardiology laboratories who had previously undergone clinically indicated rest/stress Tc-99m sestamibi or tetrofosmin SPECT. Acquisition followed ASNC guidelines (64 projections, 20-25 seconds). Processing of the full-time data sets included FBP and Astonish (FTA). A total of 32 projection data sets were created by stripping the full-time data sets and processing with Astonish (HTA). Attenuation correction was applied to both full-time and half-time Astonish-processed images (FTA-AC and HTA-AC, respectively). A consensus interpretation of three blinded readers was performed for image quality, interpretative certainty, and diagnostic accuracy, as well as severity and reversibility of perfusion and functional parameters.
Full-time and half-time Astonish processing resulted in a significant improvement in image quality in comparison with FBP. Stress and rest perfusion image quality (excellent or good) were 85%/80% (FBP), 98%/95% (FTA), and 95%/92% (HTA), respectively (p < 0.001). Interpretative certainty and diagnostic accuracy were similar with FBP, FTA, and HTA. Left ventricular functional data were not different despite a slight reduction in half-time gated image quality. Application of attenuation correction resulted in similar image quality and improved normalcy (FTA vs. FTA-AC: 76% vs. 95%; HTA vs. HTA-AC: 76% vs. 100%) and specificity (FTA vs. FTA-AC: 62% vs. 78%; HTA vs. HTA-AC: 63% vs. 84%) (p < 0.01 for all comparisons).
Astonish processing, which incorporates depth-dependent resolution recovery, improves image quality without sacrificing interpretative certainty or diagnostic accuracy. Application of simultaneously acquired attenuation correction, which includes scatter correction, to full-time and half-time images processed with this method, improves specificity and normalcy while maintaining high image quality.
KeywordsAttenuation and scatter correction instrumentation: SPECT myocardial perfusion imaging: SPECT image processing ischemia myocardial
- 3.Ye J, Song X, Zhao Z, Da Silva AJ, Weiner JS, Shao L. Iterative SPECT reconstruction using matched filtering for improved image quality. In: IEEE nuclear science symposium conference record, 29 Oct-1 Nov 2006, San Diego, CA; 2006. p. 2285-7.Google Scholar
- 6.Case JA, Cullom SJ, Bateman TM. Myocardial perfusion SPECT attenuation correction. In: Iskandrian AE, Verani MS, editors. Nuclear cardiac imaging: principles & applications. New York: Oxford University Press; 2002.Google Scholar
- 8.Cullom SJ, Krishnendu S, Hsu B. Downscatter compensation for attenuation correction with rapid 32-angle simultaneous Tc-99m emission–gadolinium-153 transmission scanning. J Nucl Cardiol 2007;14(Suppl 1):S98.Google Scholar
- 9.Cullom SJ, Saha K, Case JA. Accurate reconstruction of rapidly acquired 32-angle Gd-153 scanning line source transmission projections for myocardial perfusion SPECT attenuation correction. J Nucl Cardiol 2007;14(Suppl 1):S98-9.Google Scholar
- 11.Cerqueira MD, Weissman NJ, Dilsizian V, Jacobs AK, Kaul S, Laskey WK, et al. Standardized myocardial segmentation and nomenclature for tomographic imaging of the heart: A statement for healthcare professionals from the Cardiac Imaging Committee of the Council on Clinical Cardiology of the American Heart Association. Circulation 2002;105(4):539-42.CrossRefPubMedGoogle Scholar
- 14.Committee to Assess Health Risks from Exposure to Low Levels of Ionizing Radiation NRCotNA. Health risks from exposure to low levels of ionizing radiation: BEIR VII Phase 2. Washington, DC: The National Academies Press; 2006.Google Scholar
- 17.Bateman TM, Heller GV, McGhie AI, Courter SA, Kennedy KF, Katten D, et al. Application of simultaneous Gd-153 line source attenuation correction to half-time stress only SPECT acquisitions: A multicenter clinical evaluation. J Am Coll Cardiol 2008;51(Suppl A):A171.Google Scholar
- 19.DePuey EG, Gadiraju R, Clark J, Thompson L, Anstett F, Shwartz SC. Ordered subset expectation maximization and wide beam reconstruction “half-time” gated myocardial perfusion SPECT functional imaging: A comparison to “full-time” filtered backprojection. J Nucl Cardiol 2008;15(4):547-63.CrossRefPubMedGoogle Scholar