The efficacy of technetium-99m ciprofloxacin (Infecton) imaging in suspected orthopaedic infection: a comparison with sequential bone/gallium imaging

Technetium-99m ciprofloxacin (Infecton) has recently become established as a new radiopharmaceutical for the imaging of infection. This study was performed to determine the value of Infecton imaging in demonstrating orthopaedic infection and to compare the results with bone/gallium imaging. Twenty-two patients (12 female, 10 male; mean age 51.7+/-16.8 years) with suspected orthopaedic infective conditions were included in the study. The patients underwent three scintigraphic studies in the following sequence: 740 MBq 99mTc-methylene diphosphonate (MDP) three-phase bone scintigraphy; at least 2 days later, 370 MBq Infecton scan at 1-4 h; and finally, 185 MBq gallium-67 scintigraphy. 67Ga imaging could not be performed on four patients. All images were blindly interpreted by two independent observers. The final diagnosis was made by consensus when the readings were different. Interpretation of the early and late Infecton images was made separately, with visual findings being classified according to a four-grade scale (0, +, ++, +++). Images graded 0 and +, and also those regions which showed a decrease in uptake grade on late images as compared with early images, were classified as negative for infection; grades ++ and +++ were classified as positive. Bone/gallium images were considered positive when the images were spatially incongruent or when gallium uptake was more intense than that of 99mTc-MDP. The diagnosis was confirmed by intraoperative microbiological or histological findings, or by the presence of gross purulence. The sensitivity of Infecton imaging was found to be 85%, the specificity 92% and the accuracy 88%, as compared to figures of 78%, 100% and 90%, respectively, for bone/gallium imaging. Although the two modalities showed a similar clinical yield, the easy availability of Infecton and the short investigation time make Infecton imaging the better option for the detection of orthopaedic infection.     

The value of Tc-99m-tetrofosmin scintigraphy in the assessment of P-glycoprotein in patients with malignant bone and soft-tissue tumors

P-glycoprotein (Pgp) overexpression has been shown to be correlated with resistance to chemotherapy in patients with malignant bone and soft-tissue tumors. The aim of our study was to investigate the role of 99mTc-tetrofosmin as a functional imaging agent reflecting Pgp expression in these tumors. METHODS: Twenty eight patients with various malignant bone and soft-tissue tumors were studied. Radionuclide angiography with 99mTc-tetrofosmin was done first and planar images were acquired at 15 min and 90 min postinjection. Vascular phase was evaluated visually on dynamic images, metabolic state was evaluated both visually and quantitatively on planar images. Quantitative analysis was performed by the calculation of tetrofosmin uptake in the lesion against background and percent washout rate (WR%) of the tracer. Immunohistochemical analysis of Pgp was performed on biopsy specimens and the degree of expression was graded from 0 to 3. RESULTS: There was a positive correlation between the Pgp score and the washout rate of tetrofosmin (r = 0.73, p = 0.000). The mean washout rate of tetrofosmin from the lesions with Pgp expression (31.81 +/- 6.72) was found to be significantly higher than those of without Pgp expression (21 +/- 3.49) (p = 0.000). No statistically significant correlation was found between 15 min and 90 min uptake ratios (UR) of tetrofosmin and Pgp score (r = -0.10, p = 0.6 and r = -0.21, p = 0.2, respectively). When the cut-off value of 24.5 (according to ROC-analysis) for the washout rate was used to discriminate the lesions with and without Pgp expression, the test yielded a sensitivity value of 87.5% with a specificity of 100%. CONCLUSIONS: In malignant bone and soft-tissue tumors, 99mTc-tetrofosmin uptake were not related to Pgp overexpression. Pgp overexpression was found to be correlated with the washout rate of the tracer. 99mTc-tetrofosmin scintigraphy with washout analysis may not only be a useful method for evaluating Pgp overexpression but also its function.     

Tc-99m-tetrofosmin scintigraphy in a primary giant cell tumor of bone with pulmonary metastases

Giant cell tumor (GCT) is usually considered to be a benign entity. In rare cases, pulmonary metastases can be observed. This report documents the 99mTc-tetrofosmin scan findings of a conventional GCT of the femur and developed pulmonary nodules. The lung lesions were felt to be an example of benign metastases. According to our review, this is the first case in the literature demonstrating tetrofosmin accumulation in a GCT of bone and its pulmonary metastases.     

Comparison of direct radionuclide cystography and voiding direct cystography in the detection of vesicoureteral reflux

PURPOSE: The aim of this study is to compare the results of direct radionuclide cystography (DRNC) and voiding cystourethrography (VCUG) in a group of children with a high suspicion of vesicoureteral reflux (VUR). METHODS: For this purpose, 25 children were studied with both VCUG and DRNC. Among 50 ureter units able to be compared 39 ureter units did not show any VUR on either study. Eleven ureter units (10 children) had VUR either on one study or on both (VCUG and DRNC). In the children who had VUR on either study, a dimercaptosuccinic acid scintigraphy (DMSA) was performed to determine their cortical function. RESULTS: We identified the following four patterns: 1) Five ureter units (five children) read positive on DRNC who were negative on VCUG and four of these children had positive findings on DMSA; 2) Four ureter units (four children) read positive on VCUG who were negative on DRNC, and two of them had positive findings on DMSA; 3) Two ureters (one child) read positive in both studies and also had abnormal DMSA findings; 4) Thirty-nine ureter units read as negative on both studies. CONCLUSION: Although the results of these two methods did not show a significant difference, DRNC offers a high sensitivity in the younger age group whereas VCUG seems to be more sensitive in the older age group. DRNC also offers continuous recording during the study, ease of assessment and lower radiation dose to the gonads, which makes it a preferable method for the initial diagnosis and follow-up of VUR.     

Performance comparison of new generation HCV core antigen test versus HCV RNA test in management of hepatitis C virus infection

The study has evaluated the performance of HCV core antigen (Cag) test by comparing HCV RNA PCR assay which is considered the gold standard for management of HCV infection.Totally, 132 samples sent for HCV RNA (real-time PCR) test were included in the study. Anti-HCV antibody test and HCV Cag test were performed by chemiluminescent enzyme immunoassay (CMEI).Anti-HCV test was positive in all samples. HCV RNA was detected in 112/132 (84.8%) samples, and HCV Cag in 105/132 (79.5%). The most common HCV genotype was genotype 1 (86%). Considering the HCV RNA test as gold standard; the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of Cag test were found to be 93.75%, 100%, 100%, 74.07% and 94.69%, respectively, and paired test results were detected as highly concordant. A high level of correlation was seen between HCV RNA and Cag tests, however, the concordance between the two tests appeared to be disrupted at viral loads lower than 10³ IU/mL. On the contrary, the correlation reached significance for the values higher than 10³ IU/mL. Viral loads were in the 17–2500 IU/mL range for the negative results for Cag test. Pearson's correlation coefficient revealed a considerably high correlation.The concordance between HCV RNA and Cag tests was disrupted under a viral load lower than 10³ IU/mL. Therefore, it would be appropriate to consider cost effectiveness, advantages and limitations of the HCV RNA and Cag tests during the decision on which method to use for patient management.     

Mutations in VANGL1 associated with neural-tube defects

Neural-tube defects such as anencephaly and spina bifida constitute a group of common congenital malformations caused by complex genetic and environmental factors. We have identified three mutations in the VANGL1 gene in patients with familial types (V239I and R274Q) and a sporadic type (M328T) of the disease, including a spontaneous mutation (V239I) appearing in a familial setting. In a protein-protein interaction assay V239I abolished interaction of VANGL1 protein with its binding partners, disheveled-1, -2, and -3. These findings implicate VANGL1 as a risk factor in human neural-tube defects.     

Effect of gender on treatment and outcomes in severe aortic stenosis

The aim of this study was to evaluate the effect of gender on operative rates and outcomes in men and women with severe aortic stenosis. An institutional echocardiographic database was used to identify all adult patients with severe aortic stenosis from 2004 through 2005. Only patients with class I indication for aortic valve replacement (AVR) during the period of follow-up were included in the study. Three hundred sixty-two patients were identified with severe aortic stenosis and class I indication for AVR (52% women). Overall operative rate for the cohort was 72%. In patients who underwent AVR, Kaplan-Meier survival rates were the same for men and women. Sixty-four percent of women versus 81% of men underwent AVR (p <0.001). After adjusting for multiple covariates, women had a 2.1-fold lower odds of undergoing AVR compared to men (p = 0.02). After matching for age and Society of Thoracic Surgery risk score, women underwent AVR at a 19% lower relative rate compared to men (p = 0.03); when stratified by gender, there was no difference in reasons for not undergoing AVR. In conclusion, despite similar outcomes after surgery, women with severe aortic stenosis are less likely than men to undergo AVR.