Optimization of OSEM parameters in myocardial perfusion imaging reconstruction as a function of body mass index: a clinical approach

Abstract

ObjectiveThe present study is aimed at contributing to identify the most appropriate OSEM parameters to generate myocardial perfusion imaging reconstructions with the best diagnostic quality, correlating them with patients’ body mass index.Materials and MethodsThe present study included 28 adult patients submitted to myocardial perfusion imaging in a public hospital. The OSEM method was utilized in the images reconstruction with six different combinations of iterations and subsets numbers. The images were analyzed by nuclear cardiology specialists taking their diagnostic value into consideration and indicating the most appropriate images in terms of diagnostic quality.ResultsAn overall scoring analysis demonstrated that the combination of four iterations and four subsets has generated the most appropriate images in terms of diagnostic quality for all the classes of body mass index; however, the role played by the combination of six iterations and four subsets is highlighted in relation to the higher body mass index classes.ConclusionThe use of optimized parameters seems to play a relevant role in the generation of images with better diagnostic quality, ensuring the diagnosis and consequential appropriate and effective treatment for the patient.

Profile of MIBI Liquid Phase Radiopharmaceutical for Myocardial Imaging

“…In diagnostic applications, radiopharmaceuticals in the form of compounds that has been labeled with radioactive material are used as tracers; they are used to detect the interference and obstruction in organs and the existence of infections and tumors in the organs. Methoxyisobutylisonitrile (MIBI) is a ligand that was introduced in early 90s and is used in the manufacture of radiopharmaceuticals for myocardial perfusion diagnosis and also for cancer detection [3][4][5]. MIBI ligands are successfully synthesized at BATAN Bandung and have been utilized in the nuclear medicine at various hospitals in Indonesia such as the Hasan Sadikin Hospital in Bandung [6].…”

“…To improve the stability of liquid kit, a reformulation of the components was conducted by using two separate vials (Formulation 2) and the characteristics were compared with the one-vial formulation (Formulation 1). The MIBI Formulation 2 consists of two vials, vial A containing 0.06 mg of SnCl 2 2H 2 O and 2.6 mg Sodium Citrate 2H 2 O and vial B containing 0.5 mg of [Cu(MIBI) 4 ]BF 4 , 1 mg of cysteine hydrochloride, and 20 mg of mannitol. The purposes of this study were to determine the stability of two different formulations of MIBI as a liquid-phase kit, to compare their stability in different storage condition such as in refrigerator and freezer, and to compare the ratio of activities attained between target and nontarget organs after injection to animal model.…”

Impact of the counts density of calibration image and the image reconstruction parameters in 131I SPECT image quantification

“…However, especially in Brazilian dosimetry studies, these several days between the images acquisitions causes a large difference in the values of counts density and signal-to-noise ratio (SNR) of these acquisitions [3][4]10]. Therefore, patient imaging requires different set of reconstruction parameters for each acquisition [13]. The most widely used iterative reconstruction algorithm in clinical routine is the ordered subset expectation maximization (OSEM) scheme [11].…”

“…Because of this, images with higher counts density can be reconstructed using more iterations and subsets, resulting in a faster and more accurate final image [12]. Recently, a study for optimization of OSEM reconstruction parameters in myocardial perfusion imaging [13] showed that the arrangement of four iterations with four subsets was the most frequently selected as it produces the best image quality, but images with less attenuation could be improved using 10 iterations and 16 subsets [13].…”

Estudo de biodistribuição de radiofármaco marcado com >sup<99m>/sup<Tc pelo método invasivo e não invasivo utilizando o micro PET/SPECT/CT

“…Os algoritmos iterativos existentes se diferem, principalmente, na forma com que as projeções medidas e estimadas são comparadas, além do tipo de correções aplicadas à estimativa corrente. Tal processo pode ser iniciado por meio da criação de uma estimativa inicial com valor 0 ou 1, dependendo se a correção é realizada por meio de adição ou multiplicação, respectivamente [36].…”