Slobodanka Lj. Beatović

GammaKey system for improved diagnostics with gamma cameras.

We designed the GammaKey system for the acquisition, storage and analysis of images from semi-analogue gamma scintillation cameras (GSCs). The GammaKey system, operating on a standard PC, replicates the functionality of earlier dedicated computer systems, allows the exchange of data in the DICOM format and has an open architecture enabling the development of new diagnostic techniques. The main purpose of the GammaKey is to enable the continued use of old GSCs which have functional scintillation crystals, but also to permit data exchange with new digital GSCs. The GammaKey has been technically validated by standards established by the National Electrical Manufacturers Association. The GammaKey has been used for seven years in two leading centres for nuclear medicine in Serbia (the Clinical Center of Serbia, Belgrade, and the Clinical Center of Vojvodina, Novi Sad) in approximately 30,000 patients. Clinical application proves that the GammaKey is a robust and reliable system with high-quality image output. Data processing can be upgraded with non-standard features added on request as shown in two examples: (1) the testing of splenectomy efficacy in the case of thrombocytopenia with normal production; and (2) the detection and localisation of parathyroid adenomas.

99Tcm-p-aminohippuric acid as a new renal agent.

99Tcm-p-aminohippuric acid (99Tcm-PAH) is a new renal radiopharmaceutical prepared from a lyophilized kit by the addition of sodium pertechnetate (Na99TcmO4). Each vial contains PAH, the calcium trisodium salt of diethylenetriamine pentaacetic acid (CaNa3DTPA) and stannous chloride (SnCl2.2H2O) in an inert atmosphere. It is a stable radiopharmaceutical with high radiochemical purity (> 95%). Its protein binding is very similar to that of 131I-OIH, but it is hydrophilic in character. Animal studies using 99Tcm-PAH have indicated that it provides renal images of satisfactory quality with no external background. Despite its almost identical radiochemical purity and HPLC analysis results to 99Tcm-DTPA, 99Tcm-PAH is rapidly secreted by the kidneys in a manner consistent with tubular secretion, as confirmed by rat probenecid studies, whereas 99Tcm-DTPA is excreted by glomerular filtration. The pharmacokinetic parameters of 99Tcm-PAH (t1/2(alpha)) = 2.5 min, t1/2(beta) = 41.7 min, Cl = 5.22 ml.min-1, Kel = 5.1 x 10(-4) min-1) differ from those of 99Tcm-DTPA. Evaluation of 99Tcm-PAH in two human volunteers confirmed its good renal characteristics: rapid disappearance from the vascular system, high uptake in kidneys followed by its very fast elimination, and low residual activity 20 min after its intravenous administration.

Hybride Imaging in Evaluation of Abdominal Sarcoidosis

OBJECTIVE To determine the prevalence of abdominal involvement, distribution pattern and evaluate role of hybrid molecular imaging in patients with abdominal sarcoidosis. METHODS Between January 2010 and December 2011, 98 patients with chronic sarcoidosis and presence of prolonged symptoms or other findings suggestive of active disease were referred to FDG PET/CT examination. Active disease was found in 82 patients, and they all were screened for the presence of abdominal sarcoidosis on FDG PET/CT. All patients also underwent MDCT and assessment of serum ACE level. Follow up FDG PET/CT examination was done 12.3±5.4 months after the baseline. RESULTS Abdominal sarcoidosis was present in 31/82 patients with active sarcoidosis. FDG uptake was present in: retroperitoneal lymph nodes (77%), liver (26%), spleen (23%), adrenal gland (3%). Majority of patients had more than two locations of disease. Usually thoracic disease was spread into the extrathoracic localizations, while isolated abdominal sarcoidosis was present in 10% of patients. After first FDG PET/CT examination therapy was changed in all patients. Eleven patients came to the follow up examination where SUVmax significantly decreased in the majority of them. Three patients had total remission, three had absence of abdominal disease but discrete findings in thorax and others had less spread disease. ACE levels did not correlate with SUVmax level. CONCLUSION FDG PET/CT can be a useful tool for detection of abdominal sarcoidosis and in the evaluation of therapy response in these patients. Awareness of the presence of intra-abdominal sarcoidosis is important in order to prevent long-standing unrecognized disease.

GammaKey software for acquiring, storing, retrieving and processing images obtained by gamma camera — Benefits for clinical practice

The aim of this paper is to present the functionality and clinical application of developed GammaKey software for nuclear medicine imaging. GammaKey software consists of image acquisition module (compatibile with semi-analog gamma cameras), database, image processing module and network communication module. This software prolonged life of old gamma cameras, but also enabled image processing of DICOM data from modern gamma cameras. This paper emphasizes the importance of GammaKey application in clinical practice through several examples.

Diagnostic performance of IAEA software package for the analysis of scintigraphic renal dynamic studies: Preliminary results for semi-quantitative parameters of technetium-99m mercapto-acetyltriglycine renogram in healthy individuals

The aims of this study in healthy individuals were: a) to implement the International Atomic Energy Agency (IAEA) Software Package into analysis of technetium-99m mercapto-acetyltriglycine (99mTc MAG3) dynamic scintigraphy, b) to validate results of renogram parameters against their reference values, and c) to compare different renogram indices of kidney excretion in order to assess whether the clinical information provided by all of them is identical. Study population consisted of 20 healthy subjects who were evaluated by 99mTc MAG3 dynamic scintigraphy for kidney donation. The IAEA software was applied to process the studies. The parameters analyzed were: time to maximum activity (Tmax), time to half maximum (T1/2) of the curves, normalized residual activity at 20 minutes (NORA 20), output efficiency at 20 minutes (OE 20), residual activity (RA), elimination index (EI), whole kidney mean transit time (MTT), mean parenchymal transit time (MPTT) and relative kidney function (RF). Correspondence between OE 20, NORA 20, RA and EI was evaluated by Pearson correlation coefficient and linear regression analysis. The results for normal kidneys were presented as follows: Tmax: 3.4+0.7 min; T1/2:6.1+1.5min; NORA20:0.34+0.09;OE20: 93+2.2%; RA: 26+6.2%; EI: 2.2+0.4; MTT: 2.+0.4 min and MPTT: 1.7+0.4 min. Relative function for the left and right kidney was 52% and 48%+.4%, respectively. The excellent agreement was observed between the obtained values of renogram parameters and their reference values. Significant linear correlation between parameters of kidney excretion was obtained. The highest correlation was observed between NORA 20 and OE 20 (r=-0.936, p< 0.01). In Conclusion, the IAEA Software gives reliable values of numerical parameters of kidney excretion. Results obtained for normal kidneys were almost identical with previously reported reference values for MAG3 parameters. Only the results for MTT and MPTT were systematically lower than the established normal values. NORA 20 highly corresponds with OE 20 and could replace the former parameter in the evaluation of kidney drainage. The preliminary results support the wide-spread use of IAEA software package in order to standardize the technique of dynamic renal scintigraphy. [Projekat Ministarstva nauke Republike Srbije, br. 175018]

Evaluation in children of the standard diuretic renogram with furosemide at 20min, as compared to the diuretic renogram with furosemide after 2min

Purpose: The aims of this study in children were a) to compare the renogram with furosemide at 20min (F+20) with the renogram obtained by injecting furosemide after 2min (F+2) and b) to define the normal values of parameters for the technetium-99m mercapto-acetyl-triglycine (99mTc MAG3) diuresis renography. Patients and Methods: The investigation was carried out on the sample of 77 children: 41 boys and 36 girls (median age: 26 months, age range 2-120 months) with unilateral antenatally detected hydronephrosis (HN) and contralateral normal kidney. They were divided into two groups. Group 1 consisted of 33 children who underwent standard F+20 diuresis renography, and Group 2 of 44 children with F+2 renography. Only the normal kidneys were included in the analysis. In total, 77 kidneys were analyzed. The International Atomic Energy Agency (IAEA) software package was applied to process the studies and the following parameters were analyzed: Tmax, diuresis nephrogram in children have been calculated by the means of the IAEA software. Applying these values to semi-quantitative MAG3 parameters may help in differentiation between normal and abnormal finding of diuresis renography in children. The semi-quantitative parameters facilitate the comparison between studies during follow/up and contribute to better management of children with HN. [Projekat Ministarstva nauke Republike Srbije, br. 175018]

Uloga nuklearne medicine u transplantaciji bubrega

Znacaj uro-nefroloskih nuklearnomedicinskih metoda u ispitivanju presađenog bubrega je u pravovremenom otkrivanju komplikacija i njihovom pracenju. Rezultati ovih ispitivanja imaju visestruk znacaj: - važne su implikacije tih rezultata na klinicki stav, jer opredeljuju klinicara u cesto vitalnoj odluci između konzervativne i radikalne terapije, - rezultati nuklearnomedicinskih ispitivanja omogucuju pracenje perfuzijske funkcijske i urodinamske reakcije presađenog bubrega na lecenje, - imaju i prognosticki znacaj, jer omogucavaju da se predvidi stepen ocekivanog oporavka funkcije presađenog bubrega posle lecenja.