Fucoidans constitute a large family of sulfated polysaccharides with several biochemical properties. A commercial fucoidan from brown algae, containing low molecular weight polysaccharidic species ...constituted of l-fucose, uronic acids and sulfate groups, was simply treated here with calcium acetate solution. This treatment led to a purified fraction with a yield of 45%. The physicochemical characterizations of the purified fucoidan using colorimetric assay, MALLS, dRI, FT-IR, NMR, exhibited molecular weight distributions and chemical profiles similar for both fucoidans whereas the sulfate and l-fucose contents increased by 16% and 71%, respectively. The biodistribution study in rat of both compounds labeled with 99mTc evidenced a predominant renal elimination of the purified fucoidan, but the crude fucoidan was mainly retained in liver and spleen. In rat myocardial ischemia-reperfusion, we then demonstrated the better efficiency of the purified fucoidan. This purified sulfated polysaccharide appears promising for the development of molecular imaging in acute coronary syndrome.
Abstract Cardiovascular magnetic resonance (CMR) has evolved from a pioneering research tool to an established noninvasive imaging method for detecting inducible myocardial perfusion deficits. In ...this consensus document, experts of different imaging techniques summarize the existing body of evidence regarding CMR perfusion as a viable complement to other established noninvasive tools for the assessment of perfusion and discuss the advantages and pitfalls of the technique. A rapid, standardized CMR perfusion protocol is described, which is safe, clinically feasible, and cost-effective for centers with contemporary magnetic resonance equipment. CMR perfusion can be recommended as a routine diagnostic tool to identify inducible myocardial ischemia.
The aim of this study was to compare the diagnostic performances for the detection of myocardial ischemia of 82-Rb-PET-MPS and 99m-Tc-SPECT-MPS in overweight individuals and women.
Men with BMI ≥ 25 ...and women referred for MPS were considered for inclusion. All individuals underwent 99m-Tc-SPECT-MPS with CZT cameras and 82-Rb-PET-MPS in 3D-mode. Individuals with at least one positive MPS were referred for coronary angiography (CA) with FFR measurements. A criterion for positivity was a composite endpoint including significant stenosis on CA or, in the absence of CA, the occurrence of acute coronary event during the following year. 313 patients (46% women) with mean BMI of 31.8 ± 6.5 were included. Sensitivity for the detection of myocardial ischemia was higher with 82-Rb-PET-MPS compared with 99m-Tc-SPECT-MPS (85% vs. 57%, P < .05); specificity was equally high with both imaging techniques (93% vs. 94%, P > .05). 82-Rb-PET allowed for a more accurate detection of patients with a high-risk coronary artery disease (HR-CAD) than 99m-Tc-SPECT-MPS (AUC = 0.86 vs. 0.75, respectively; P = .04).
In women and overweight individuals, 82-Rb-PET-MPS provides higher sensitivity for the detection of myocardial ischemia than 99m-Tc-SPECT-MPS thanks to a better image quality and an improved detection of HR-CAD.
Abstract Objectives This study sought to compare techniques evaluating cardiac dysautonomia and predicting the risk of death of patients with hereditary transthyretin amyloidosis (mATTR) after liver ...transplantation (LT). Background mATTR is a multisystemic disease involving mainly the heart and the peripheral nervous system. LT is the reference treatment, and pre-operative detection of high-risk patients is critical. Cardiovascular dysautonomia is commonly encountered in ATTR and may affect patient outcome, although it is not known yet which technique should be used in the field to evaluate it. Methods In a series of 215 consecutive mATTR patients who underwent LT, cardiac dysautonomia was assessed by a dedicated clinical score, time-domain heart rate variability,123 -meta-iodobenzylguanidine heart/mediastinum (123 -MIBG H/M) ratio on scintigraphy, and heart rate response to atropine (HRRA). Results Patient median age was 43 years, 62% were male and 69% carried the Val30Met mutation. Cardiac dysautonomia was documented by at least 1 technique for all patients but 6 (97%). In univariate analysis, clinical score,123 -MIBG H/M ratio and HRRA were associated with mortality but not heart rate variability. The123 -MIBG H/M ratio and HRRA had greater area under the curve (AUC) of receiver-operating characteristic curves than clinical score and heart rate variability (AUC: 0.787, 0.748, 0.656, and 0.523, respectively). Multivariate score models were then built using the following variables: New York Heart Association functional class, interventricular septum thickness, and either123- MIBG H/M ratio ( S MIBG ) or HRRA ( S atropine ). AUC of S MIBG and S atropine were greater than AUC of univariate models, although nonsignificantly (AUC: 0.798 and 0.799, respectively). Predictive powers of S MIBG , S atropine , and a reference clinical model (AUC: 0.785) were similar. Conclusions Evaluation of cardiac dysautonomia is a valuable addition for predicting survival of mATTR patients following LT. Among the different techniques that evaluate cardiac dysautonomia,123 -MIBG scintigraphy and heart rate response to atropine had better prognostic accuracy. Multivariate models did not improve significantly prediction of outcome.
Dose kernel convolution (DK) methods have been proposed to speed up absorbed dose calculations in molecular radionuclide therapy. Our aim was to evaluate the impact of tissue density heterogeneities ...(TDH) on dosimetry when using a DK method and to propose a simple density-correction method.
This study has been conducted on 3 clinical cases: case 1, non-Hodgkin lymphoma treated with (131)I-tositumomab; case 2, a neuroendocrine tumor treatment simulated with (177)Lu-peptides; and case 3, hepatocellular carcinoma treated with (90)Y-microspheres. Absorbed dose calculations were performed using a direct Monte Carlo approach accounting for TDH (3D-RD), and a DK approach (VoxelDose, or VD). For each individual voxel, the VD absorbed dose, D(VD), calculated assuming uniform density, was corrected for density, giving D(VDd). The average 3D-RD absorbed dose values, D(3DRD), were compared with D(VD) and D(VDd), using the relative difference Δ(VD/3DRD). At the voxel level, density-binned Δ(VD/3DRD) and Δ(VDd/3DRD) were plotted against ρ and fitted with a linear regression.
The D(VD) calculations showed a good agreement with D(3DRD). Δ(VD/3DRD) was less than 3.5%, except for the tumor of case 1 (5.9%) and the renal cortex of case 2 (5.6%). At the voxel level, the Δ(VD/3DRD) range was 0%-14% for cases 1 and 2, and -3% to 7% for case 3. All 3 cases showed a linear relationship between voxel bin-averaged Δ(VD/3DRD) and density, ρ: case 1 (Δ = -0.56ρ + 0.62, R(2) = 0.93), case 2 (Δ = -0.91ρ + 0.96, R(2) = 0.99), and case 3 (Δ = -0.69ρ + 0.72, R(2) = 0.91). The density correction improved the agreement of the DK method with the Monte Carlo approach (Δ(VDd/3DRD) < 1.1%), but with a lesser extent for the tumor of case 1 (3.1%). At the voxel level, the Δ(VDd/3DRD) range decreased for the 3 clinical cases (case 1, -1% to 4%; case 2, -0.5% to 1.5%, and -1.5% to 2%). No more linear regression existed for cases 2 and 3, contrary to case 1 (Δ = 0.41ρ - 0.38, R(2) = 0.88) although the slope in case 1 was less pronounced.
This study shows a small influence of TDH in the abdominal region for 3 representative clinical cases. A simple density-correction method was proposed and improved the comparison in the absorbed dose calculations when using our voxel S value implementation.
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