An in vitro comparative study of bioglass and biologically derived hydroxyapatite with bone scintigraphy (BS) method

Four rabbits received human derived HA to their left tibias. After 16 weeks bioglass was implanted to their right tibias. After other 16 weeks bone scintigraphies were taken with Tc-99m-MDP. Three phase bone scan images showed no evidence of inflammation and superior vascularization rates at implantation sites. In this study, bioglass demonstrated higher uptake of Tc-99m-MDP comparing to HA, suggesting a higher vascularization rate and better osseointegration

EWING TUMOR OF THE MANDIBLE

A primary Ewing's tumor in the mandible is reported, and the diagnostic imaging features of this lesion are discussed. Modalities used included panoramic and plain films, computed tomography, and Tc-99m-MDP scintigraphy

EWING TUMOR OF THE MANDIBLE

A primary Ewing's tumor in the mandible is reported, and the diagnostic imaging features of this lesion are discussed. Modalities used included panoramic and plain films, computed tomography, and Tc-99m-MDP scintigraphy

Correlation of technetium-99m MIBI and thallium-201 retention in solitary cold thyroid nodules with postoperative histopathology

A comparative prospective study of technetium-99m methoxyisobutylisonitrile (MIBI) and thallium-201 with early (15 min) and delayed (90 min for MIBI, 3 h for Tl-201) imaging in the differentiation of thyroid lesions is presented, Forty patients with cold thyroid nodules visualised on Tc-99m-pertechnetate scan and with dyskaryotic or atypical epithelial cells verified by fine-needle aspiration biopsy underwent MIBI and Tl-201 scintigraphy at 3-day intervals. Subsequent thyroidectomies were carried out in all patients. Semiquantitative analysis was performed using a lesion to non-lesion ratio on early (ER) and delayed images (DR). Additionally, a retention index (RI) was calculated using the formula RI=(DR-ER) x 100/ER. The reproducibility of the method for the early and delayed measurements was tested by analysing intra- and inter-observer variability and repeatability coefficients. Histopathologically, the nodules were found to be well-differentiated thyroid cancer in 21 patients and benign in 19 patients. There was no significant difference in the ER between malignant and benign lesions for either Tl-201 or MIBI (P>0.05). However, for both agents significant differences were found between malignant and benign lesions with regard to DR (P0.05) except with regard to DR and RI in malignant nodules (P<0.05). A receiver operating characteristic analysis was performed to determine threshold levels for the differentiation of malignant from benign nodules. Following this analysis, ER, DR and RI levels of 1.03, 1.54 and 2 for MIBI and less than or equal to 1.42, 1.24 and 5 for Tl-201 were selected. Using these threshold levels, the sensitivity, specificity and accuracy of the study were 90.5%, 36.8% and 65% for ER MIBI, 61.9%, 94.7% and 77.5% for DR MIBI, 95.2%, 89.4% and 92.5% for RI MIBI, 85.7%, 47.3% and 67.5% for ER Tl-201 , 80.9%, 73.6% and 77.5% for DR Tl-201, and 90.5%, 4.7% and 92.5% for RI Tl-201. In conclusion, the DR for MIBI and Tl-201 is superior to the ER in detecting malignant nodules, and the RI for both MIBI and Tl-201 is more valuable than the DR in differentiating malignant from benign thyroid nodules

CLINICAL COMPARISON OF TECHNETIUM-99M-EC, TECHNETIUM-99M-MAG3 AND IODINE-131-OIH IN RENAL DISORDERS

Technetium-99m-ethylenedicysteine has recently been developed for renal function studies. The pharmacokinetics of Tc-99m-EC were studied by constant infusion technique and compared with Tc-99m-MAG3 and I-131-OIH in, 11 patients with various renal disorders. Methods: After giving a 7.4 MBq I-131-OIH and 90-110 MBq Tc-99m-EC or Tc-99m-MAG3 bolus, a constant infusion (1 MBq/ml Tc-99m-agent and 0.07 MBq/m I-131-OIH was started. Sixteen blood and five urine samples were obtained over three hr. Results: The renal clearance of Tc-99m-EC was higher than that of Tc-99m-MAG3. The Tc-99m-EC/OIH and (99m)TcMAG3/OIH ratios were 0.75 +/- 0.05 and 0.55 +/- 0.10 (p = 0.00087), respectively. The distribution volume of Tc-99m-EC was also higher than that of Tc-99m-MAG3 (15722 +/- 4644 and 9509 +/- 2788 m1/1.73m(2), respectively; p = 0.072). The Tc-99m-EC/OIH and Tc-99m-MAG3/OIH distribution volume ratios were 1.03 +/- 0.14 and 0.55 +/- 0.10, respectively (p = 0.0003). The 60-min excretion values of Tc-99m-EC and Tc-99m-MAG3 were compared to that of OIH. The Tc-99m-EC/OIH and Tc-99m-MAG3/OIH excretion ratios were 0.96 +/- 0.06 and 1.07 +/- 0.10, respectively (p = 0.162). The protein binding of Tc-99m-EC and OIH were found to be 34% +/- 4 and 66% +/- 5, respectively (p < 0.0001). The red cell binding of Tc-99m-EC was negligible (3% +/- 1.2) in comparison to OIH (27% +/- 3; p < 0.0001). Conclusion: This limited study demonstrates the pharmacokinetic and renal clearance properties of Tc-99m-EC. This agent has good potential for renal function evaluation