Aim. Similar to PET, absolute quantitative imaging is becoming available in commercial SPECT/CT devices. This study's goal was to assess quantitative accuracy of activity recovery as a function of image reconstruction parameters and count statistics in a variety of phantoms. Materials and Methods. We performed quantitative 99mTc-SPECT/CT acquisitions (Siemens Symbia Intevo, Erlangen, Germany) of a uniform cylindrical, NEMA/IEC, and an anthropomorphic abdominal phantom. Background activity concentrations tested ranged: 2–80 kBq/mL. SPECT acquisitions used 120 projections (20 s/projection). Reconstructions were performed with the proprietary iterative conjugate gradient algorithm. NEMA phantom reconstructions were obtained as a function of the iteration number (range: 4–48). Recovery coefficients, hot contrast, relative lung error (NEMA phantom), and image noise were assessed. Results. In all cases, absolute activity and activity concentration were measured within 10% of the expected value. Recovery coefficients and hot contrast in hot inserts did not vary appreciably with count statistics. RC converged at 16 iterations for insert size > 22 mm. Relative lung errors were comparable to PET levels indicating the efficient integration of attenuation and scatter corrections with adequate detector modeling. Conclusions. The tested device provided accurate activity recovery within 10% of correct values; these performances are comparable to current generation PET/CT systems.
Background and aims: The role of portal vein thrombosis (PVT) in the natural history of cirrhosis is controversial. There are few prospective studies validating risk factors for development of PVT. We analysed the incidence, factors associated with PVT development and its influence on cirrhosis decompensations and orthotopic liver transplant (OLT)-free survival. Methods: In this prospective observational study between January 2014 and March 2019, 445 consecutive patients with chronic liver disease were screened and finally 241 with cirrhosis included. Factors associated with PVT development and its influence on cirrhosis decompensations and OLT-free survival by time dependent covariate coding were analysed. Results: Majority of patients belonged to Child-Pugh class A 184 (76.3%) and the average MELD score was 10 ± 5. Previous cirrhosis decompensations occurred in 125 (52.1%), 63 (26.1%) were on NSBB and 59 (27.2%) had undergone banding for bleeding prophylaxis. Median follow-up was 29 (1-58) months. Cumulative incidence of PVT was 3.7% and 7.6% at 1 and 3 years. Previous decompensation of cirrhosis and low platelet counts but not NSBB independently predicted the development of PVT. During follow-up, 82/236 (34.7%) patients developed cirrhosis decompensations.OLT-free survival was 100% and 82.8% at 3 years, with and without PVT respectively. MELD score, but not PVT, independently predicted cirrhosis decompensations (HR 1.14; 95%CI:1.09-1.19) and OLT-free survival (HR 1.16;95%CI:1.11-1.21).
OBJECTIVES:The aim of this work was to study the interaction between genetic polymorphisms (single-nucleotide polymorphisms, SNPs) of pro-and anti-inflammatory cytokines and fat intake on the risk of developing Crohn's disease (CD) or modifying disease activity.
METHODS:Seven SNPs in interleukin 1 (IL1), tumor necrosis factor alpha (TNFα), lymphotoxin alpha (LTα), and IL6 genes were analyzed in 116 controls and 99 patients with CD. The type of fat intake was evaluated, and the interaction between SNPs and dietary fat in modulating disease activity was analyzed.
RESULTS:Individuals who were homozygous for the IL6−174G/C polymorphism had a six-fold higher risk for CD (odds ratio (OR)=6.1; 95% confidence interval (95% CI)=1.9-19.4), whereas the TT genotype on the TNFα−857C/T polymorphism was associated with more active disease (OR=10.4; 95% CI=1.1-94.1). A high intake of total, saturated, and monounsaturated fats, as well as a higher ratio of n-6/n-3 polyunsaturated fatty acid (PUFA), was associated with a more active phenotype (P<0.05). Furthermore, there was an interaction between dietary fat intake and SNPs, with a high intake of saturated and monounsaturated fats being associated with active disease, mainly in patients carrying the variant alleles of the 857 TNFα polymorphism (OR=6.0, 95% CI=1. OR=5.17; respectively) and the 174 IL6 polymorphism (OR=2.95; 95% CI=1.0-9.1; OR=3.21; 95% CI=1.0-10.4, respectively). Finally, low intake of n-3 PUFA and high n-6/n-3 PUFA ratio in patients with the TNFα 857 polymorphism were associated with higher disease activity (OR=3.6; 95% CI=1.0-13.0; OR=5.92; 95% CI=1.3-26.5, respectively).CONCLUSIONS:
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