sodium-pertechnetate-tc-99m and Arteriosclerosis

The biodistribution and removal from plasma (measured as fractional clearance rate, FCR, per hour) of native and oxidatively modified 99mtechnetium-labeled beta-very low density lipoprotein (99mTc-beta-VLDL) were investigated in hypercholesterolemic (HC) and control (C) three-month old New Zealand rabbits. The intracellular accumulation of beta-VLDL labeled with 99mTc was studied in vitro in THP-1 cells and monocyte-derived macrophages isolated from rabbits. After intravenous injection into C rabbits, copper-oxidized beta-VLDL (99mTc-ox-beta-VLDL) was cleared from the circulation faster (0.362 +/- 0.070/h) than native beta-VLDL (99mTc-nat-beta-VLDL, 0.241 +/- 0.070/h). In contrast, the FCR of 99mTc-ox-beta-VLDL in HC rabbits was lower (0.100 +/- 0.048/h) than that of 99mTc-nat-beta-VLDL (0.163 +/- 0.043/h). The hepatic uptake of radiolabeled lipoproteins was lower in HC rabbits (0.114 +/- 0.071% injected dose/g tissue for 99mTc-nat-beta-VLDL and 0.116 +/- 0.057% injected dose/g tissue for 99mTc-ox-beta-VLDL) than in C rabbits (0.301 +/- 0.113% injected dose/g tissue for 99mTc-nat-beta-VLDL and 0.305 +/- 0.149% injected dose/g tissue for 99mTc-ox-beta-VLDL). The uptake of 99mTc-nat-beta-VLDL and 99mTc-ox-beta-VLDL by atherosclerotic aorta lesions isolated from HC rabbits (99mTc-nat-beta-VLDL: 0.033 +/- 0.012% injected dose/g tissue and 99mTc-ox-beta-VLDL: 0.039 +/- 0.017% injected dose/g tissue) was higher in comparison to that of non-atherosclerotic aortas from C rabbits (99mTc-nat-beta-VLDL: 0.023 +/- 0.010% injected dose/g tissue and 99mTc-ox-beta-VLDL: 0.019 +/- 0.010% injected dose/g tissue). However, 99mTc-nat-beta-VLDL and 99mTc-ox-beta-VLDL were taken up by atherosclerotic lesions at similar rates. In vitro studies showed that both monocyte-derived macrophages isolated from rabbits and THP-1 macrophages significantly internalized more 99mTc-ox-beta-VLDL than 99mTc-nat-beta-VLDL. These results indicate that in cholesterol-fed rabbits 99mTc-ox-beta-VLDL is slowly cleared from plasma and accumulates in atherosclerotic lesions. However, although the extent of in vitro uptake of 99mTc-ox-beta-VLDL by macrophages was high, the in vivo accumulation of this radiolabeled lipoprotein by atherosclerotic lesions did not differ from that of 99mTc-nat-beta-VLDL.

Topics: Animals; Arteriosclerosis; Lipids; Lipoproteins, VLDL; Macrophage Activation; Male; Metabolic Clearance Rate; Rabbits; Sodium Pertechnetate Tc 99m; Tissue Distribution

A 68-year-old woman with long-standing hypertension was referred to us. Her plain roentgenogram and tomogram of the chest revealed a nodular mass seen within the right apical lung field. Angiography and computed tomography revealed that this mass, possibly simulating an intrapulmonary mass lesion, was actually due to arteriosclerotic buckling of the distal segment of the innominate artery. This made a posterior-downward protrusion into the lung from the soft tissue above the right lung apex.

Topics: Aged; Arteriosclerosis; Brachiocephalic Trunk; Diagnosis, Differential; Female; Humans; Sodium Pertechnetate Tc 99m; Solitary Pulmonary Nodule; Technetium; Tomography, X-Ray; Tomography, X-Ray Computed

Topics: Animals; Aorta; Arteriosclerosis; Digitonin; Endothelium; Female; Fibrinogen; Iodine Radioisotopes; Macromolecular Substances; Rabbits; Radionuclide Imaging; Serum Albumin; Serum Albumin, Radio-Iodinated; Sodium Pertechnetate Tc 99m; Technetium; Technetium Tc 99m Aggregated Albumin; Time Factors

We perform scinti-angiography regularly in suspected cases of dissecting aneurysms. In our experience, the dissection is well demonstrated by this method. In correctly selected cases, scinti-angiography is a method which is well tolerated by the patient and which carries very little risk, since the complications due to contrast media are absent.

Topics: Aortic Aneurysm; Aortic Dissection; Aortography; Arteriosclerosis; Diagnosis, Differential; Hematoma; Humans; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Technetium; Tomography, X-Ray Computed