ABSTRACT
Heart imaging radiopharmaceuticals could improve the diagnostic value of routine heart scanning for detecting cardiac disorders. The aim of the study was to prepare high radiochemical purity [99m]Tc-Digoxin in a yield of about 98%. The optimal conditions for labelling were as follows: 100microg of Digoxin, 2microg of SnCl2·2H2O, room temperature [25 +/- 1°C], reaction retention time of 30 min at pH 7. Under these conditions, the radiochemical yield of [99m]Tc-Digoxin reaches 98%. In vivo bio distribution was performed in normal Swiss Albino mice at different time intervals after administration of [99m]Tc-Digoxin.Scintigraphic study of [99m]Tc-Digoxin was performed in rabbits. The heart uptake of 99m Tc-Digoxin was sufficiently high and thus may be a potential myocardial imaging radiopharmaceutical applicable in cardiology
ABSTRACT
Tc labeled N-N-ethylene-L, L-dicysteine [EC] was introduced in form of multiple-step kit as an alternate renal imaging radiopharmaceutical for commonly used [99m] Tc-MAG3. We developed a single component lyophilized kit of EC ready to be labeled with [99m]Tc
We present the optimization of the components of our formulation, its evaluation in animal models, normal human volunteers and patients of various renal diseases, in comparison with[99m] Tc-MAG3. Efficient labeling of EC was achieved with our preparation at pH 7 to 12. The formulation at pH 8 was used further for bio distribution studies in organs of sacrificed Sprague Dawley rats and a live rhesus monkey using scintigraphy
After satisfactory bio-distribution results, the kit was then evaluated in normal human volunteers through renography. But the renogram parameters of [99m] Tc-EC[pH 8] were statistically inferior to[99m] Tc-MAG3. Surrogate kit at pH 10 was therefore developed and re-evaluated in rats for organ bio distribution. After favorable results the kit was then assessed further in normal volunteers and a group of patients with various renal disorders via scintigraphy
The EC kit developed at pH 10 gave images better than and scintigraphic parameters comparable to [99m] Tc-MAG3. It was concluded that single vial kit we formulated easy to prepare than three-vial kit and can be used as an alternate to[99m] Tc-MAG3
ABSTRACT
To determine an association between chronic tobacco use and changes in cerebral perfusion through semi-quantitative scintigraphic assessment employing metastable Technetium-99 labelled hexa-methyl propylene amine oxime single photon emission computed tomography [Tc-99m HMPAO SPECT]. Design: Case-control study. Place and duration of study: The study was conducted at the Department of Medical Sciences, Pakistan Institute of Engineering and Applied Sciences [PIEAS], Nilore, Islamabad, from Oct 2001 to May 2002. Regional cerebral perfusion in 48 chronic tobacco users was evaluated, utilising a normal database created by HMPAO brain scans of 20 non-tobacco users. Subjects were classified into chronic tobacco users and non-tobacco users through the use of the smoking index [SI]. [Smoking Index = Number of years of tobacco use x Number of cigarettes smoked per day]. SI value of 100 was taken as the cut-off value. Regions of interest [ROIs] were declared hypoperfused or hyperperfused if their percentage perfusion values relative to the average perfusion per pixel of the whole slice under evaluation did not fall within + 2 standard deviation [SD] of the mean regional perfusion in the corresponding ROI, in the normal control group. Result: Chronic tobacco users showed 164 hypoperfused ROIs [6.57%] and 138 hyperperfused ROIs [5.53%] out of 2496 ROIs assessed, whereas the normal controls showed only 15 hypoperfused [1.44%] and 27 hyperperfused [2.60%] ROIs out of 1040 ROIs assessed [P < 0.001]. Cerebral perfusion in chronic tobacco users was found to be significantly decreased compared to the non-tobacco users