EJNMMI Res. 2015 Mar 22;5:16. doi: 10.1186/s13550-015-0086-2. eCollection 2015.
Optimisation of quantitative lung SPECT applied to mild COPD: a software phantom simulation study.
EJNMMI research
Pernilla Norberg, Anna Olsson, Gudrun Alm Carlsson, Michael Sandborg, Agnetha Gustafsson
Affiliations
Affiliations
- Medical Radiation Physics, Department of Medical and Health Sciences, Linköping University, Linköping, 581 83 Sweden ; Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, 581 83 Sweden.
- Medical Radiation Physics, Department of Medical and Health Sciences, Linköping University, Linköping, 581 83 Sweden ; Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, 581 83 Sweden ; Clinical Physiology, Department of Medical and Health Sciences, Linköping University, Linköping, 581 83 Sweden.
- Department of Medical Physics, Karolinska University Hospital, Huddinge, Stockholm 141 86 Sweden.
PMID: 25853022
PMCID: PMC4385278 DOI: 10.1186/s13550-015-0086-2
Abstract
BACKGROUND: The amount of inhomogeneities in a (99m)Tc Technegas single-photon emission computed tomography (SPECT) lung image, caused by reduced ventilation in lung regions affected by chronic obstructive pulmonary disease (COPD), is correlated to disease advancement. A quantitative analysis method, the CVT method, measuring these inhomogeneities was proposed in earlier work. To detect mild COPD, which is a difficult task, optimised parameter values are needed.
METHODS: In this work, the CVT method was optimised with respect to the parameter values of acquisition, reconstruction and analysis. The ordered subset expectation maximisation (OSEM) algorithm was used for reconstructing the lung SPECT images. As a first step towards clinical application of the CVT method in detecting mild COPD, this study was based on simulated SPECT images of an advanced anthropomorphic lung software phantom including respiratory and cardiac motion, where the mild COPD lung had an overall ventilation reduction of 5%.
RESULTS: The best separation between healthy and mild COPD lung images as determined using the CVT measure of ventilation inhomogeneity and 125 MBq (99m)Tc was obtained using a low-energy high-resolution collimator (LEHR) and a power 6 Butterworth post-filter with a cutoff frequency of 0.6 to 0.7 cm(-1). Sixty-four reconstruction updates and a small kernel size should be used when the whole lung is analysed, and for the reduced lung a greater number of updates and a larger kernel size are needed.
CONCLUSIONS: A LEHR collimator and 125 (99m)Tc MBq together with an optimal combination of cutoff frequency, number of updates and kernel size, gave the best result. Suboptimal selections of either cutoff frequency, number of updates and kernel size will reduce the imaging system's ability to detect mild COPD in the lung phantom.
Keywords: Computer-assisted image analysis; Lung diseases; Quantitative evaluation; SPECT; Simulation; Technegas
References
- Semin Nucl Med. 2010 Nov;40(6):467-73 - PubMed
- J Appl Physiol. 1969 Sep;27(3):328-35 - PubMed
- EJNMMI Res. 2013 Apr 19;3(1):28 - PubMed
- J Nucl Med. 2013 Sep;54(9):1588-96 - PubMed
- Phys Med Biol. 1998 Jun;43(6):1713-30 - PubMed
- J Aerosol Med. 2006 Spring;19(1):8-20 - PubMed
- Nucl Med Commun. 2007 Dec;28(12 ):929-36 - PubMed
- IEEE Trans Med Imaging. 1994;13(4):601-9 - PubMed
- EJNMMI Res. 2014 Dec;4(1):39 - PubMed
- Comput Methods Programs Biomed. 1989 Aug;29(4):257-72 - PubMed
- Phys Med Biol. 2000 Nov;45(11):3431-40 - PubMed
- Eur J Nucl Med Mol Imaging. 2009 Aug;36(8):1356-70 - PubMed
- Nucl Med Commun. 2007 Sep;28(9):719-25 - PubMed
- Eur Respir J Suppl. 1993 Mar;16:5-40 - PubMed
- J Nucl Med. 2001 Aug;42(8):1288-94 - PubMed
- J Nucl Med. 2000 Apr;41(4):590-5 - PubMed
- Phys Med Biol. 2010 Apr 7;55(7):1971-88 - PubMed
- Intensive Care Med. 1982;8(4):173-7 - PubMed
Publication Types