68Ga-DOTA-E[c(RGDfK)]2 PET Imaging of SHARPIN-Regulated Integrin Activity in Mice

Autor: Riikka Siitonen, Anne Roivainen, Meeri Käkelä, Heidi Liljenbäck, Johanna Ivaska, Tiina Saanijoki, Elina Mattila, Anu Autio, Sirpa Jalkanen, Ingrid Dijkgraaf, Emilia Peuhu, Olli Metsälä
Přispěvatelé: RS: CARIM School for Cardiovascular Diseases, Biochemie, RS: Carim - B01 Blood proteins & engineering, RS: CARIM - R1 - Thrombosis and haemostasis
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Zdroj: Journal of Nuclear Medicine, 60(10), 1380-1387. Society of Nuclear Medicine and Molecular Imaging
ISSN: 1535-5667
0161-5505
DOI: 10.2967/jnumed.118.222026
Popis: 1380 Objectives: The purpose of this study was to investigate how gender, BMI, patient cross-sectional area and heart size affect the influence of time-of-flight (TOF) and point spread function (PSF) modeling in image reconstruction on regional absolute myocardial blood flow (MBF) measured with 82Rb PET in an obese population. Methods: Dynamic rest/stress 82Rb cardiac PET studies were performed for 30 obese subjects on a TOF PET scanner. Subject characteristics were (mean ± SD for continuous variables): gender 9 male, 21 female; weight 138.9 ± 32.8 kg; BMI 47.8 ± 9.5 kg/m2; heart size 92.4 ± 55.3 ml; cross-sectional area in a transaxial slice containing the heart 1133 ± 233 cm2. Images were reconstructed in four ways: (1) OSEM without TOF or PSF modeling (OSEM), (2) OSEM with TOF (TOF), (3) OSEM with PSF modeling (PSF) and (4) OSEM with TOF and PSF modeling (PSFTOF). All were with 3 iterations, 8 subsets and with a post-reconstruction 8mm 3D Gaussian filter. A one tissue compartmental model was used to compute MBF. Average rest and stress flow and myocardial flow reserve were computed in five regions: anterior, septal, inferior, lateral and apical. Results from TOF, PSF and PSFTOF were compared with those from OSEM, with subjects grouped by gender, and by tertiles (10 subjects each) for BMI (I: 32.5-40.5, II: 41.1-52.3, III: 53.3-75.6 (kg/m2)), cross-sectional area (I: 532 - 1086, II: 1089 - 1157, III: 1187 - 1662 (cm2)) and heart size (I: 19 -56, II: 66 - 93, III: 97 - 238 (ml)). The MBF or myocardial flow reserve (MFR) in a given region was compared with the corresponding OSEM value and the change was expressed as a percent. Results: The general trends for all subjects with TOF were similar MBF increases in the apical (+22.0%) and septal walls (+19.4%), and a slightly lower increase in the anterior wall (+11.3 %). Increases were small in the inferior (+4.6%) and lateral (+4.9%) walls. There was little effect of PSF modeling in any region. MBF trends with PSFTOF were similar to those for TOF alone. Rest and stress increases with TOF tended to be matched, so that MFR was little changed. Trends were examined for the groupings by patient characteristics. (1) Gender. MBF showed a greater increase with TOF for females (mean +20.9%) compared to males (mean +14.9%) in the apical, septal and anterior walls. Results with PSFTOF were similar. (2) BMI. The MBF increase with TOF in the apical, anterior and septal walls was greatest for tertile II (mean +26.9%) compared with tertile I (mean +13.6%) and tertile III (mean +16.7%). (3) Cross-sectional area. The MBF increase with TOF in the apical, anterior and septal walls was similar for tertiles II (mean +22.1%) and III (mean +22.6%), and was greater than that for tertile I (mean +12.6%). (4) Heart size. The MBF increase with TOF in the apical, anterior and septal walls was greater for smaller heart sizes: tertile I (mean +21.2%), tertile II (+20.7%) and tertile III (+15.3%). These results are for our patient population and particular hardware, software and processing implementation. Conclusions: Patient gender, BMI, cross-sectional area and heart size affect the degree to which MBF values change with TOF. The largest changes are observed for females, patients with larger BMI, larger cross-sectional area and smaller hearts. The greatest changes are found in the apical, septal and lateral walls. The studied patient characteristics have little effect on flow reserve. It is important to consider these patient-dependent effects when evaluating absolute MBF in a clinical environment, and to recognize that equipment or protocol changes may affect MBF results.
Databáze: OpenAIRE
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