A simple and sensitive derivative spectrophotometric method has been developed for the determination of thallium(III) using a newly synthesized reagent diacetylmonoxime-(p-anisyl)-thiosemicarbazone in acetic acid medium. The molar absorptivity and Sandell’s sensitivity of the coloured species are 5.6×10 L mol cm and 3.6 ng cm, respectively. Beer’s law is obeyed between 0.25 and 2.60 μg mL of Tl...

To determine the effect of exercise myocardial scintigraphy with thallium-201 on diagnostic accuracy and the need for coronary angiography, consecutive patients with a variety of clinical presentations were identified. Clinical summaries, including a detailed history, physical examination, and complete data from a standard treadmill exercise test, were presented to 91 cardiologists. The cardiol...

+ 6%). The exercise time and maximal heart rate were similar in the two groups. Two patients with cardiomyopathy and 11 with coronary artery disease had a positive exercise ECG (p < 0.05). Thallium scans showed perfusion defects in all 25 patients. The perfusion defects were complete in nine coronary artery disease patients (60%) and in one patient (10%) with cardiomyopathy (p < 0.05). Extensiv...

+ 6%). The exercise time and maximal heart rate were similar in the two groups. Two patients with cardiomyopathy and 11 with coronary artery disease had a positive exercise ECG (p < 0.05). Thallium scans showed perfusion defects in all 25 patients. The perfusion defects were complete in nine coronary artery disease patients (60%) and in one patient (10%) with cardiomyopathy (p < 0.05). Extensiv...

An audit has been performed of the value of parathyroid hormone assays and thallium-technetium isotope scanning in the pre-operative investigation of 67 hypercalcaemic patients referred for surgery over a 5 year period. Parathyroid hormone assay by region-specific technique was found to have a diagnostic sensitivity of 75% (n = 52) whilst the more recent assay for the intact molecule was 97% se...

Seventy-six thallium-201 myocardial perfusion studies were performed on twenty-five patients to assess their reproducibility and the effect ofvarying the level of exercise on the results of imaging. Each patient had a thallium-201 study at rest. Fourteen patients had studies on two occasions at maximum exercise, and twelve patients had studies both at light and at maximum exercise. Of 70 segmen...

The broadening and shift of the 535.0 nm thallium line resulting from the photodissociation of thallium iodide perturbed by helium, neon and argon were investigated at low densities using a photoelectric Fabry-Perot interferometer. The Doppler and collision broadening components of the line profiles have been determined. Linear variations of both the Lorentzian half-width and the shift of the l...

We describe a 51-year-old woman with a cerebral infarction that showed transient accumulation of thallium-201. On admission, this lesion was well-enhanced by gadolinium injection and gradually expanded, mimicking a malignant brain tumor. A cerebral angiogram, however, did not indicate the presence of a malignant brain tumor. Ethyl cysteinate dimer single photon computerized tomography showed pe...

The valence state of thallium determines its toxicity, distribution and mobility. Tl(I) can be oxidized to Tl(III) under photoirradiation of the high-pressure mercury arc lamp and solar light. A photooxidation experiment of thallium showed that the photooxidation rate could be affected by the pH of the solution, and the intensity and wavelength of the light source. Lowering the pH and increasin...

a D t t H w l c T t l t a e 9 2 r t c A i “ e 9 n a s t s r m m p i Thallium-201 has several virtues as a myocardial perfusion agent. It is one of the best of the soluble agents for measuring regional myocardial perfusion, because it has a blood clearance half-time of 30 s and a first pass extraction in the myocardium of 88% (1) (compared with the 1-min blood clearance half-time [2] and 50% to ...