Subclinical cerebral involvement in Behcet's disease: a SPECT study.

Neurologic involvement has been reported in Behcet's disease (BD) with prevalence rates of 4-49%. Involvement of the central nervous system (CNS) usually follows systemic manifestations of BD by months to years, but as the initial future in only 5% of cases. The variance of the prevalence rates of neurologic involvement in BD raises the possibility of subclinical neurologic involvement. For the purpose of explaining the variance in the prevalence rates, 20 patients with BD, but without neurological symptoms and signs, were investigated by using cerebral single photon emission computed tomography (SPECT) which seems to be more convenient for BD than other scanners. A control group of patients with various diseases that were not expected to influence the cerebral blood flow was included. Brain magnetic resonance imaging (MRI) scans were performed in cases in which abnormal SPECT findings were obtained. Decreased and asymmetrical tracer uptakes were detected in 35% of patients with BD. MRI scans were normal in these patients. We concluded that functional imaging using SPECT may detect abnormalities at an initial stage prior to their progression to morphological damage detectable by MRI, and this imaging modality can be used even in cases which show no neurologic symptom to indicate the subclinical neurologic involvement.

The role of 99Tcm-tetrofosmin myocardial perfusion scintigraphy in the assessment of patients with previous myocardial infarction: a comparative study with 201Tl.

The aim of this study was to determine the utility of 99Tcm-tetrofosmin cardiac imaging in patients with previous myocardial infarction and with significant coronary artery disease (CAD) compared with that of 201Tl cardiac imaging. Sixteen patients (14 males, 2 females) were studied by same-day exercise-rest 99Tcm-tetrofosmin imaging and exercise, rest and reinjection 201Tl cardiac imaging. For each study, semi-quantitative visual analysis was performed in 20 segments using a 4-point scale. The regional distribution and defect reversibility with the two tracers were compared with the results of coronary angiography. A total of 320 segments were analysed. There was a statistically significant concordance between the numbers of fixed and reversible segments in both studies in myocardial segments supplied by totally occluded coronary arteries (Group 1), as well as in segments supplied by significantly stenosed coronary vessels (Group 2). The exercise and rest uptake of both 99Tcm-tetrofosmin and 201Tl in myocardial segments supplied by totally occluded coronary arteries with poor collateral flow was significantly lower compared with segments supplied by totally occluded coronary arteries with efficient collateral flow (P < or = 0.05). When the uptake of both tracers was analysed according to each major vascular territory, the mean exercise and rest uptake grades of 99Tcm-tetrofosmin and 201Tl were similar. There was also no significant difference in defect reversibility between the two tracers. Discordant results were observed in the territory of the right coronary artery in Group 1 (mean exercise grade of 99Tcm-tetrofosmin = 2.26 +/- 0.7 and of 201Tl = 1.92 +/- 0.8; P < or = 0.001) and in Group 2 (mean grade of 99Tcm-tetrofosmin = 0.79 +/- 0.65 and of 201Tl = 0.95 +/- 0.65; P < or = 0.05). The results of the present study indicate that the overall diagnostic utility of 99Tcm-tetrofosmin in the identification of individual stenosed vessels is comparable with 201Tl in both patients with totally occluded coronary arteries and those with significantly stenosed vessels. The regional distribution of both tracers was lower in myocardial segments supplied by totally occluded coronary arteries with poor collateral flow.

Evaluation of palpable breast masses with 99Tcm-MIBI: a comparative study with mammography and ultrasonography.

We evaluated the feasibility of 99Tcm-methoxyisobutylisonitrile (MIBI) as a tumour localizing agent in patients with palpable breast masses in comparison with mammography and ultrasonography (US). Forty-one patients with palpable masses were studied. An additional 12 women with no palpable breast anomaly also underwent 99Tcm-MIBI breast study. Multiple views were obtained and semiquantitative evaluation was applied. Mammography and US revealed all of the malignant breast masses but differential diagnosis of fibroadenomas could not be achieved. Twenty-five of 27 breast carcinomas were detected using 99Tcm-MIBI scintigraphy. Two patients with invasive lobular carcinoma showed absent MIBI accumulation. Eight of 14 axillary lymph-node metastases showed positive uptake (57%). Twelve of 14 patients with pathologically proven benign breast lesions did not demonstrate any MIBI accumulation. Focal MIBI uptake could be observed in two fibroadenomas. The sensitivity and the specificity of semiquantitative MIBI analysis were 93 and 86%, respectively. Subjective grading offered no additional help in the further differentiation of malignant breast masses. There was no significant difference between histopathological types of breast carcinomas and uptake grades. Our results indicate that 99Tcm-MIBI scintigraphy may provide additional information in the differentiation of malignant pathologies from benign lesions in patients with palpable breast anomalies.

Accumulation of 99Tcm-polyclonal immunoglobulin in different stages of infection: an experimental study.

In this experimental study, the utility of 99Tc(m)-polyclonal human immunoglobulin (99Tcm-HIG) for localizing acute and chronic phases of inflammatory lesions was investigated. Three groups of rats were inoculated with Staphylococcus aureus in the right thigh. Then, 24 h (group I, n = 12), 48 h (group II, n = 12) and 72 h (group III, n = 12) post-inoculation, the rats received 40 MBq 99Tcm-HIG into the jugular vein. In addition, two control rats were studied at 24 h after inoculation of sterile saline. Both visual and quantitative evaluations were undertaken. The acute and chronic stages of inflammation were determined by pathological examination. The mean ( +/- S.D.) lesion/contralateral uptake ratios at 4 and 24 h after 99Tcm-HIG injection were: group I, 1.22 +/- 0.1 and 2.12 +/- 0.16; group II, 1.15 +/- 0.08 and 2.25 +/- 0.16; group III, 1.06 +/- 0.09 and 2.08 +/- 0.14. In conclusion, the acute and chronic phases of infection showed non-significant differences in 99Tcm-HIG uptake ratios.

Comparison of fixation methods in treating mandibular fractures: scintigraphic evaluation.

The effects of rigid and nonrigid fixation methods in the treatment of long bones have been studied by many authors. A comparison of these two methods has been undertaken on long bones and documented in previous studies. However, there appears to be no such research on facial bone fractures. In this study a mandibular model was selected as an appropriate model for fracture site mobility in the face. Twenty-three patients with mandibular fractures were admitted to the study. Two groups were formed. The first group consisted of intermaxillary fixation patients and the second group was comprised of internal rigid fixation-treated patients. The callus deposit was evaluated by the technetium 99m methylene diphosphonate scintigraphic method on days 1, 10, 20, 30, and 40 postoperatively. The results of the study showed that the greatest level of callus formation is in the second exposure (days 1 to 10) for the first group and in the third exposure (days 10 to 20) for the second group. This study demonstrates that minimal motion on the fracture line after intermaxillary fixation increases local blood circulation and osteoblastic activity. The callus deposit reaches maximum in a short period of time with nonrigid fixation.