tellurium and Ischemia

Fluorescence located in 1500-1700 nm (denoted as the near-infrared IIb window, NIR-IIb) has drawn great interest for bioimaging, owing to its ultrahigh tissue penetration depth and spatiotemporal resolution. Therefore, NIR-IIb fluorescent probes with high photoluminescence quantum yield (PLQY) and stability along with high biocompatibility are urgently pursued. Herein, a novel NIR-IIb fluorescent probe of Au-doped Ag

Topics: Animals; Biocompatible Materials; Cell Line; Cell Survival; Disease Models, Animal; Gold; Hindlimb; Humans; Ischemia; Mice; Mice, Inbred BALB C; Neovascularization, Pathologic; Quantum Dots; Signal-To-Noise Ratio; Silver; Spectroscopy, Near-Infrared; Tellurium

Transient ischemic dilation (TID) of the left ventricle (LV) has not been validated as a marker of extensive coronary artery disease (CAD) for studies using a cadmium-zinc-telluride (CZT) camera with upright imaging.. TID ratios were obtained from upright stress and rest images on a CZT camera. Separate cut-off values were determined for exercise and for regadenoson stress. The cutoffs were then applied to 28 patients with extensive CAD and 101 patients without extensive CAD.. With treadmill exercise, an upright TID ratio ≥1.16 provided a positive predictive value of 50% and a negative predictive value of 85.4% for the identification of extensive CAD. In the regadenoson group, an upright TID ratio of 1.29 provided a positive predictive value of 20% and a negative predictive value of 75.9%. Although not an independent predictor of extensive CAD in all subjects, in subjects with a normal upright LVEF, it provided a predictive value by receiver operating characteristics comparable to the SSS.. Increased upright TID measurements on a CZT camera are associated with extensive CAD. The upright TID measurements can serve in an adjunctive role to SSS, and may be most effective in patients with a normal upright exercise LVEF.

Topics: Aged; Cadmium; Cohort Studies; Coronary Angiography; Coronary Artery Disease; Diagnosis, Computer-Assisted; Dilatation; Exercise Test; Female; Heart Ventricles; Humans; Image Processing, Computer-Assisted; Ischemia; Male; Middle Aged; Myocardial Perfusion Imaging; Predictive Value of Tests; Purines; Pyrazoles; Retrospective Studies; ROC Curve; Sensitivity and Specificity; Tellurium; Tomography, Emission-Computed, Single-Photon; Zinc

Cadmium zinc telluride (CZT) detectors with linear counting rate response enable count subtraction in sequential scanning. We evaluated whether count subtraction eliminated the need for higher activity doses in the second part of the 1-d stress-rest myocardial perfusion imaging (MPI) protocol.. For 50 patients (mean age ± SD, 66 ± 12 y) with visually abnormal (n = 42) or equivocal (n = 8) adenosine-stress MPI (320 MBq of (99m)Tc-tetrofosmin) on a CZT camera, rest MPI was performed with a low dose (320 MBq) and repeated after injection of an additional 640 MBq of (99m)Tc-tetrofosmin to achieve a standard 3-fold increased dose at rest (960 MBq), compared with stress (320 MBq). Low-dose rest myocardial perfusion images were reconstructed after subtracting the background activity of the preceding stress scan. Segmental percentage tracer uptake of the 2 rest myocardial perfusion images (320 vs. 960 MBq) was compared using intraclass correlation and Bland-Altman limits of agreement. Patient- and coronary territory-based clinical agreement was assessed.. The standard protocol revealed ischemia in 34 (68%) and a fixed defect in 8 (16%) patients, of whom 33 (97%) and 8 (100%) were correctly identified by low-dose MPI (clinical agreement, 98%). Segmental uptake correlated well between low- and standard-dose rest scans (r = 0.94, P < 0.001; Bland-Altman limits of agreement, -11 to +11%). Defect extent was 14.4% (low-dose) versus 13.1% (standard-dose) at rest (P = not statistically significant) and 26.6% at stress (P < 0.001 vs. rest scans).. These promising results suggest that accurate assessment of ischemic myocardial disease is feasible with a low-dose-low-dose 1-d SPECT MPI protocol using a CZT device.

Topics: Adult; Aged; Aged, 80 and over; Cadmium; Female; Humans; Image Processing, Computer-Assisted; Ischemia; Male; Middle Aged; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Phantoms, Imaging; Radiopharmaceuticals; Semiconductors; Tellurium; Tomography, Emission-Computed, Single-Photon; Zinc

The accuracy of the 133Xe washout method and the validity of newly developed cadmium telluride CdTe(Cl) minisemiconductor detectors were estimated by performing comparative, simultaneous measurements of both cutaneous (CBF) and subcutaneous (SBF) blood flow using 2 conventional scintillation sodium iodide NaI(Tl) and CdTe(Cl) detectors over the same radioactive depot in each of 10 individuals. The accuracy of the 133Xe washout method was found to be 13-15% (C.V.) for the CBF measurements and 9-12% (C.V.) for the SBF measurements. The CdTe(Cl) detectors, which have a weight of 20 g and were attached directly over the radioactive depot, may replace stationary NaI(Tl) detectors placed 20 cm from the depot for measurements of both CBF and SBF. Two CdTe(Cl) detectors were used for estimations of the local variation in CBF and SBF within a distance of 5 cm in normal skin of 10 individuals. The C.V. was 7% for the CBF measurements and 18% for the SBF measurements. Measurements of CBF and SBF were performed in 6 psoriatic patients who, after about 1 week of antipsoriatic treatment with beech tar, developed typical Woronoff rings. The local CBF differed significantly from the center of psoriatic plaques to the margin, in the Woronoff ring, and in nonlesional skin. In contrast, SBF was remarkably equal within the plaque and in the Woronoff ring. The color of the Woronoff ring cannot be ascribed to a local cutaneous vasoconstriction. Cutaneous blood flow in chronic stable, lesional psoriatic skin was significantly lower than previously published values for active lesional psoriatic skin, but significantly higher than CBF in normal individuals. Measurements of CBF in tetrahydrofurfuryl nicotinic acid (Trafuril)-treated skin showed higher values than measurements of CBF in the postischemic hyperemia period both in normal and in lesional psoriatic skin. Trafuril induced a significant increase of CBF in both lesional and nonlesional skin. The high CBF rates in lesional psoriatic skin are not due to a maximally, passively dilated vascular bed.

Topics: Adult; Aged; Cadmium; Cadmium Compounds; Female; Furans; Humans; Ischemia; Male; Middle Aged; Nicotinic Acids; Psoriasis; Regional Blood Flow; Skin; Sodium Iodide; Tellurium; Xenon Radioisotopes