Cytologic changes induced by 131I in the thyroid glands of patients with hyperthyroidism; results of fine needle aspiration cytology.

Cytological changes in the thyroid glands of 120 patients who had received 131I treatment for hyperthyroidism were examined in detail. The cytological material was obtained by fine needle aspiration cytology. The patients were divided into four groups according to the amount of time elapsed after the 131I treatment. The control groups were selected from euthyroid patients with hypoactive or non-functional solitary nodules and patients with Graves' disease who had not received 131I therapy. The thyrocytes revealed degenerative changes in the immediate period after cessation of treatment. One year after the treatment some non-specific changes, such as oxyphilic metaplasia and regeneration, were seen. No malignant change has been observed clinically or cytologically during up to 20 years of follow up since receiving 131I.

Technetium-99m-N,N-ethylenedicysteine--a comparative study of renal scintigraphy with technetium-99m-MAG3 and iodine-131-OIH in patients with obstructive renal disease.

UNLABELLED: Technetium-99m-labeled N,N-ethylenedicysteine (99mTc-EC) is a new renal imaging agent introduced as an alternative for 99mTc-labeled mercaptoacetyltriglycine (99mTc-MAG3), with similar renal excretion characteristics. To evaluate the diagnostic characteristics of this agent, a gamma camera study was performed. METHODS: Sixteen patients with obstructive renal disease and six normal controls were injected with 90 to 110 MBq of 99mTc-EC and 7.4 MBq 131I-labeled orthoiodohippurate (OIH). Serial images were obtained during 20 min for 99mTc-EC and 30 min for OIH. The study was repeated using 90 to 110 MBq 99mTc-MAG3 during the same week. RESULTS: Renograms, functional ratios and urinary excretion patterns of all three agents were similar. The mean time to peak activity values for OIH, 99mTc-EC and 99mTc-MAG3 were 4.25 +/- 0.37 min, 4.39 +/- 0.32 min and 4.00 +/- 0.24 min, respectively. The time from peak to 50% activity values for OIH, 99mTc-EC and 99mTc-MAG3 were 5.48 +/- 0.80 min, 6.93 +/- 0.69 min and 7.33 +/- 0.85 min, respectively. CONCLUSION: It is concluded that 99mTc-EC has excellent imaging characteristics and similar excretion properties to OIH. The advantages of 99mTc-EC over 99mTc-MAG3 are lower hepatobiliary uptake and simplicity of preparation.

Functional evaluation of renal transplants with scintigraphy.

A variety of techniques have been employed to assess renal function and its evolution after transplant surgery. Since initial perfusion studies are easy to perform, one may be tempted to rely on 99mTc-diethylenetriaminepentaacetic acid (DTPA) scanning alone. Some discrepancies have been observed between perfusion studies and clinical outcome of the renal transplant patients however. We therefore decided to evaluate both 99mTc-DTPA and 131I-hippuran renal scanning in 28 renal transplant patients. Sixty 99mTc-DTPA perfusion and 131I hippuran scintigraphies were performed using a same-day protocol. The examinations were repeated in 14 patients at weekly or monthly intervals to monitor the clinical trend of these patients. The results of this study indicate that, for early detection of the kidney problems, 131I-hippuran scintigraphy was superior to 99mTc-DTPA perfusion scans, but for the proper clinical management of renal transplant patients, both procedures should be utilized.

Prediction of muscle viability after electrical burn necrosis.

In this preliminary study, Tc-99m MIBI, a muscle perfusion agent, was used to assess the viability of tissues in two patients with extensive high-tension electrical burns. This proved to be an easy and definitive diagnostic procedure and a practical solution to determining the level of amputation before surgery.

Muscle perfusion with technetium-MIBI in lower extremity peripheral arterial diseases.

There have been several methods utilized in the diagnosis or assessment of medical or surgical treatments of peripheral arterial diseases. In this study, the diagnostic value of a new tracer: 99mTc-methoxy-isobutyl-isonitrile (MIBI) has been demonstrated in patients with leg claudication. We successively performed muscle perfusion scans in 6 normals and 18 patients with claudication pain during rest and after exercise on the same day. Muscle perfusion abnormalities in all patients were consistent with the defects in the arteries of the affected limbs. The results show that this is a simple and accurate diagnostic procedure and superior to those that have been previously used.

Effects of defibrotide on peripheral obliterative vascular diseases.

Twenty-nine patients with atherosclerotic obliterative vascular disorder and 9 cases of Buerger's disease were treated with 600 mg defibrotide daily for 10 days and then three times weekly for 3 months. The response to therapy was evaluated from hemostatic parameters, venostasis test (cuff test), treadmill testing, and radionuclide arteriography. We observed increased pain-free intervals in daily life and during treadmill testing. There was also a significantly higher response in the cuff test and improved perfusion as seen by radionuclide arteriography.

Radionuclide imaging of Meckel's diverticulum: cimetidine versus pentagastrin plus glucagon.

The aim of this study was to investigate the effects of prior administration of cimetidine in radionuclide imaging of Meckel's diverticulum. In three groups of seven rats with artificial Meckel's diverticulum, containing ectopic gastric mucosa, the effects of pentagastrin + glucagon plus 99mTc-pertechnetate, as well as cimetidine premedication plus 99mTc-pertechnetate, and 99mTc-pertechnetate alone were compared to attain improved radionuclide imaging of Meckel's diverticulum. This experimental model suggests that the use of cimetidine seemed to have some advantages: (a) nontarget (intestinal) radioactivity was diminished by cimetidine, (b) the target to nontarget (Meckel's diverticulum to intestinal activity) ratio increased with cimetidine pretreatment. This resulted in an enhanced accumulation of pertechnetate in the ectopic gastric mucosa, and reduced excretion of the radionuclide into the lumen. Consequently, better scintiphotograms and a low rate of false results added to the validity of this method.

99mTc-gentamicin: chemical and biological evaluation.

99mTc-Gentamicin complex, a new agent for renal studies, is prepared by the reduction of pertechnetate by stannous chloride. Organ distribution in rats and paper chromatography with Whatman 3MM paper [developed in n-butanol, acetic acid, and water (4:1:1)] were favored as analytical tools for determination of labeling parameters of 99mTc-Gentamicin. A higher concentration of stannous ion is responsible for the formation of insoluble technetium species which concentrate in the liver. The mean kidney: liver ratio of 10.4:1 was obtained 1 h after injection. This confirms that scintigraphic delineation of kidneys is highly satisfactory.