Browsing by Author "Radulović, Marija (56789775400)"

Background/Aim. Although the number of new primary implantation of hip and knee prostheses every year increases, the rate of failed arthroplasty is nearly the same. The main question is whether it is an aseptic instability or instability caused by infection. The aim of this preliminary study was an attempt with combined 99mTc-ciprofloxacin and 99mTc-methylene diphosphonate (MDP) bone scintigraphy to improve diagnostic accuracy in the differentiation of hip and knee prosthesis aseptic loosening and periprosthetic joint infection. Methods. Inclusion criteria of patients for this study were based on suspected periprosthetic joint infection: painful prosthetic joint, restricted joint movements and increased value of erythrocyte sedimentation rate or levels of C-reactive protein. We examined 20 patients with implanted 14 hip and 6 knee prosthesis. All patients also underwent plain radiography of suspected joint. In all patients, three-phase 99mTc-MDP bone scintigraphy was performed. Three to five days after the bone scan, we performed scintigraphy using 99mTc-ciprofloxacin with the calculation of accumulation index. Periprosthetic joint infection was confirmed on the basis of microbiological findings. Results. Periprosthetic joint infection was confirmed in fourteen of twenty observed joints, in five of them the aseptic loosening was present and in one patient’s symptoms were not related to the prosthesis (poor biomechanics of prosthetic joints caused by weaknesses of muscle). Estimated sensitivity/specificity for 99mTc-MDP bone scintigraphy alone were 100/17%; for 99mTc-ciprofloxacin scintigraphy were 85,7/100%. Sensitivity and specificity were 92,3% and 83,3%, respectively for results obtained with combined assessment by both methods. Our study confirmed the high negative predictive value of 99mTc-MDP bone scan. The negative result of bone scan virtually excludes the possibility of periprosthetic infection. On the other hand, positive findings of 99mTc-MDP scintigraphy cannot with certainty confirm the infection. Conclusion. Combined 99mTc-MDP scintigraphy with 99mTc-ciprofloxacin scintigraphy significantly increases the ability of differentiation of aseptic loosening from periprosthetic joint infection. © 2017, Institut za Vojnomedicinske Naucne Informacije/Documentaciju. All rights reserved.

Introduction/Objective Nuclear Medicine Section of IAEA has developed the software for dynamic renal scintigraphy, which allows calculation of advanced parameters of drainage: renal output efficiency (OE) and normalized residual activity (NORA). The aim of this study was to validate IAEA software by comparing results of parameters of renal drainage in normal subjects against their established reference values and to assess diagnostic accuracy of OE and NORA in distinguishing between obstruction/unobstruction. Methods Fifty-five patients with suspected obstruction and 36 kidney donors were investigated. Group A consisted of 24 obstructed kidneys, Group B of 37 kidneys with dilated urinary tract, and Group C of 72 normal kidneys. Forty-minute acquisition was applied. Furosemide was administered after 20 minutes. Post-micturition image was acquired at 50 minutes. The analyzed parameters were as follows: OE at 20 minutes (OE20) and at the end of the furosemide test (OE40), NORA at 20 minutes (NORA20) and after micturition (NORAPM). One-way ANOVA was used for evaluating the differences between the groups. Ability of OE40 and NORAPM to distinguish between obstruction/unobstruction was determined by ROC curve analysis. The sensitivity, specificity, area under the curve, and cut-off values were analyzed. Results Excellent agreement of our results with established OE and NORA values was found. The difference between the groups was significant for OE20, OE40, NORA20,and NORA (p < 0.001). Cut-off values PM for obstruction were 82% and 0.11 for OE40 and NORAPM, respectively. Conclusion IAEA software gives reliable analysis of diuretic renography and helps to better diagnose obstruction. IAEA should be encouraged to produce final version of the software and to release it online. © 2021, Serbia Medical Society. All rights reserved.

Objective The aim of this study was to estimate interobserver reproducibility of Tc-99m mercaptoacetyltriglycine renography in children and adults by assessing the parameters of the International Atomic Energy Agency (IAEA) software for the analysis of dynamic renal studies. Methods The renograms of 65 children and 65 adults covered a wide age range, different quality of drainage, overall function and differential renal function (DRF). Three observers were processing parameters of the IAEA software. Normalized residual activity at 20 min (NORA20), NORA on the postmicturition acquisition (NORApm), PM to maximum renal count ratio (PM/max), output efficiency at 20 min (OE20), OE 20 min after diuretic stimulation (OEF + 20), whole kidney mean transit time (MTT) and DRF by integral and Rutland-Patlak were calculated by observers. Results The overall agreement between three observers was almost perfect [the average intraclass correlation coefficient (ICC) above 0.99] in children and adults, with no significant difference between the parameters of renal drainage, transit and DRF. ICCs for all parameters were higher than 0.980 in children under 12 months, even slightly greater for PM/max and OEF+20. In children with poor/incomplete drainage and DRF below 40%, ICCs were above 0.98. In the subgroup of adults with impaired overall tubular extraction rate, level of reproducibility was almost perfect. Slightly lower but still insignificant values of ICC were presented in adults with poor/incomplete drainage. Conclusion Our results indicate an excellent interobserver reproducibility for all quantitative parameters of IAEA software in both pediatric and adult patients. © 2020 Lippincott Williams and Wilkins. All rights reserved.

Background/Aim. In the last five decades primary hip and knee arthroplasty is the most common and effective surgical intervention worldwide. Infection, although unfrequented, is the most serious complication. Nuclear medicine imaging, not affected by metallic hardware, is the current imaging modality of choice for the evaluation of suspected joint replacement infection. The aim of this study was to estimate the diagnostic accuracy of three phase 99m technetium methylene diphosphonate (99mTc-MDP) bone scintigraphy in periprosthetic hip and knee joint infection. Methods. Inclusion criteria of patients in the study were suspected knee or hip periprosthetic joint infections. In this study, we examined 45 patients (14 men and 31 women) with 39 hip and 24 knee prosthesis (total 63). In all patients, three-phase bone scintigraphy was performed after intravenous application of 555 MBq of 99mTc-MDP. The final confirmation of infection was microbiological or pathohistology finding. Results. Infection was confirmed in 29 prosthetic joints, in 13 (44.8%) knee and 16 (55.2%) hip joints while there was no infection in 34 prosthetic joints. The connection of different modalities of negative and positive findings 99mTc-MDP three-phase bone scintigraphy with the final confirmation of infection showed a high statistical significance (p < 0.001). Three phase bone scintigraphy showed a high sensitivity of 90% but a modest specificity of 69.7% in the detection of periprosthetic infection with the diagnostic accuracy of 79%. The calculated positive predictive value was 73% but the negative predictive value was high 89%. Our results of three-phase bone scintigraphy with calculated sensitivity, specificity and diagnostic accuracy of 79% are in consent with the majority of published studies, or even slightly better. Conclusion. Bone scintigraphy is sensitive in the diagnosis of periprosthetic infection but insufficiently specific. In the detection of periprosthetic infections three-phase bone scan can be used as a diagnostic method of the first line only aimed at its exclusion. The only reasonable use of bone scintigraphy is in combination with other radionuclide methods with high specificity. © 2017, Institut za Vojnomedicinske Naucne Informacije/Documentaciju. All Rights Reserved.