Emilija Jaksic

Donor Kidney Glomerular Filtration Rate and Post-Transplant Graft Function

This study aimed to estimate the relationship between the single kidney glomerular filtration rate (SKGFR) of a planned kidney transplant and the subsequent graft function and survival of living related kidney recipients (LKRs). Of 180 LKRs with the graft functioning for more than a year, 70 patients without delayed graft function (DGF) or acute rejection (AR) were selected for the study. According to SKGFR, assessed by 99mTcDTPA, the patients were allocated into Group 1, receiving kidney with SKGFR < 50 mL/min (32 patients), and Group 2, with SKGFR > 50 mL/min (38 patients). The database included donor, recipient and transplant variables. No significant difference was found between the patient and graft survival rate, creatinine clearance (CCr) and the rate of CCr change between the groups. Additional evaluation revealed no significant influence of the ratio of SKGFR and the recipients body weight/size on patient and graft outcome. The analysis of factors of influence on patient and graft survival and function revealed the major influence of nonimmunological factors but not of SKGFR of the transplanted kidney. Our study did not confirm the influence of SKGFR on graft function and survival in the LKRs without DGF and AR but the limited number of patients must not be disregarded.

Site of myocardial infarction and severity of perfusion abnormalities impact on post-stress left ventricular function in patients with single-vessel disease: gated single-photon emission computed tomography methoxyisobutylisonitrile study.

ObjectivesWe used gated single-photon emission computed tomography methoxyisobutylisonitrile (SPECT MIBI) to (i) determine whether location of myocardial infarction (MI) and severity of perfusion abnormalities affect post-stress left ventricular function in patients with single-vessel coronary artery disease, and (ii) correlate changes between post-stress and rest ejection fraction (EF) with the severity of perfusion and regional wall motion abnormalities (RWMAs). MethodsEighty-eight patients with a history (≥3 months) of anterior MI (n=45) or inferior MI (n=43) underwent a 2-day stress–rest gated SPECT MIBI. 4D-MSPECT software was used to calculate left ventricular end-diastolic volume (EDV), end-systolic volume (ESV), EF, and the difference from post-stress to rest EF (EFs–EFr). Summed stress scores, summed rest scores, and summed difference scores (SDS) were calculated based on the 17-segment model. RWMAs were visually assessed using a 5-point score. ResultsPatients with anterior MI, compared with those with inferior MI, showed significantly greater perfusion abnormalities (summed stress score 11.0±5.5 vs. 7.5±2.4, P<0.01, summed rest score 7.4±4.7 vs. 5.2±1.9, P<0.01, SDS 3.3±1.0 vs. 1.9±1.0, P<0.05) and higher post-stress and rest RWMA (RWMSS 12.2±6.0 vs. 8.7±4.1, P<0.01, RWMRS 8.7±5.4 vs. 5.6±3.0, P<0.01). In 22 patients with anterior reversible ischemia in addition to fixed defect, post-stress and rest EDV and ESV were significantly larger and post-stress EF decreased more than in 21 patients with inferior MI (EDV 144.0±28.9 ml vs. 108.6±36.9 ml, ESV 70.6±22.2 ml vs. 53.4±20.5 ml, EFs–EFr −4.2±3.5% vs. −1.5±2.2%, P<0.01). SDS and RWMA were highly correlated with EFs–EFr. ConclusionIn patients with single-vessel coronary artery disease, the extent and severity of perfusion and RWMAs assessed by gated SPECT MIBI are greater after anterior MI than inferior MI. Global left ventricular function is significantly more affected after anterior MI only in patients with reversible ischemia in addition to fixed wall defect. Decrease in EF from post-stress to rest is closely associated with the severity of perfusion and RWMAs. Overall results suggest that the extent and severity of perfusion and RWMAs are more prominent in the myocardial region supplied by left anterior descending coronary artery than by right coronary artery, which may explain significantly worse post-stress left ventricular function after anterior MI.

The utility of two somatostatin analog radiopharmaceuticals in assessment of radiologically indeterminate pulmonary lesions.

Purpose: The aim of our study was to assess diagnostic accuracy of Tc-99m depreotide and Tc-99m-EDDA/HYNIC-TOC scintigraphy for evaluation of pulmonary lesions that appeared ambiguous on computed tomography (CT). Material and Methods: Forty-nine consecutive patients (37 men and 12 women; mean age, 60 ± 11 years) with 60 pulmonary lesions on chest radiography and CT were referred for nuclear imaging. They were prospectively allocated to undergo whole-body scintigraphy (WBS) and single photon emission computed tomography (SPECT) using either Tc-99m depreotide (26 patients, group 1) or Tc-99m-EDDA/HYNIC-TOC imaging (23 patients, group 2). Histologic findings after tissue biopsy served as a gold standard for determining diagnostic accuracy of the 2 somatostatin analogs. Visual assessment was complemented by semiquantitative analysis based on target to background ratio. Results: Among the 32 pulmonary lesions scanned with Tc-99m depreotide, focal uptake was increased in 22 of 25 malignancies, whereas no uptake was found in 6 of 7 benign lesions (88% sensitivity, 85% specificity, and 88% accuracy) on both WBS and SPECT. Imaging of 28 pulmonary lesions with Tc-99m-EDDA/HYNIC-TOC had a similar diagnostic yield (sensitivity 87%, specificity 84%, and accuracy 86%). Overall, target to background ratios were higher on SPECT than WBS but not significantly different between groups 1 and 2 (SPECT 2.72 ± 0.70 vs. 2.71 ± 0.50, WBS 1.61 ± 0.32 vs. 1.62 ± 0.28, respectively). Conclusion: This study demonstrates that Tc-99m depreotide and Tc-99m-EDDA/HYNIC-TOC have similar diagnostic value for characterizing pulmonary lesions that appear ambiguous on CT.

Diagnostic and prognostic value of gated SPECT MIBI early post-stress imaging in patients with intermediate Duke Treadmill Score.

Purpose of the ReportThe aims of this study were to compare perfusion and functional parameters between early (ES) and standard (SS) post-stress gated SPECT MIBI, to validate ES against coronary angiography, and to determine whether ES parameters can predict future cardiac events. Patients and MethodsThe sample included 63 patients with normal or mildly impaired left ventricular function and intermediate Duke Treadmill Score. They underwent a 2-day stress-rest gated SPECT MIBI with the post-stress data acquired at 15 minutes (ES) and 60 minutes (SS) after i.v. injection of 740 MBq of 99mTc-MIBI. The ES findings were compared to SS and against coronary angiography to determine their sensitivity/specificity for detecting >70% stenosis. The information about new-onset cardiac events was collected 26 ± 6 months later. ResultsPerfusion parameters did not significantly differ between ES and SS. Ejection fraction was significantly lower and regional wall motion abnormalities were significantly higher on ES than SS. The corresponding perfusion and functional parameters were strongly related (linear regression slope 0.65–1.00, intercept −0.36–8.5, R2 0.98–0.75). ES parameters had high sensitivity (96%) and specificity (83%) for detecting >70% stenosis. Lower early stress than rest EF (>5%), higher early stress than rest EDV, and early SSS >8 emerged as significant predictors of new-onset cardiac events. ConclusionsEarly post-stress gated SPECT MIBI yields comparable perfusion and functional parameters as the standard post-stress protocol. ES parameters are useful for detecting the existing coronary disease and for predicting future cardiac events. ES protocol is recommended for improving patient compliance and efficiency of nuclear cardiology services.

Investigation of blood perfusion and metabolic activity of brain tumours in adults by using 99mTc-methoxyisobutylisonitrile.

Objectives(i) To examine blood perfusion and metabolic activity of various brain tumours using radionuclide cerebral angiography (RCA) and single-photon emission tomography (SPET) after a single dose of 99mTc-methoxyisobutylisonitrile (MIBI). (ii) To examine if the inclusion of RCA can improve insight into the relative contribution of tumour perfusion to the uptake of MIBI shown by SPET, and to improve evaluation of tumour biology. (iii) To determine the value and the roles of MIBI in the management of brain tumour patients. MethodsFifty adult patients (38 male, 12 female) with a total of 56 intracranial space-occupying lesions have been included prospectively, 37 of which were newly diagnosed and the remaining with signs of recurrence/rest of earlier resected and irradiated brain tumours. The control group consisted of nine volunteers with no evidence of organic cerebral disease. Scintigraphic examination consisted of a dynamic first-pass study lasting 60 s (3 s/frame) and two SPET studies (60 projections each, 25 s/projection), starting 15 min and 2 h after intravenous injection of MIBI. Regions of interest of the tumour and normal brain tissue were drawn on RCA and both early and delayed SPET slices. The following tumour/brain activity ratios have been calculated: (i) tumour perfusion index (P); (ii) early uptake index (E); (iii) delayed uptake index (D); and(iv) retention index (R). Analogous indices have been calculated from the same examinations performed in controls, reflecting maximal physiologic regional variations of perfusion and uptake in brain tissue. ResultsMean P of various brain tumours (low-grade gliomas 0.98, anaplastic gliomas 1.14, glioblastoma multiforme 1.20, metastases 1.09, lymphomas 1.08) differ little from each other and do not exceed maximal physiologic regional variations of cerebral perfusion (1.33), with the exception of meningioma (1.87, F=2.83, P=0.015). The receiver operating characteristics curve analysis of P showed that for the cut-off value of 1.45 the sensitivity for distinguishing meningioma from other tumours is 75%, specificity 87%, positive predictive value 33% and negative predictive value 97%. Mean E of malignant brain tumours (8.3, n=31, 23 primary, eight secondary), except anaplastic gliomas (3.5, n=5), differed significantly (P=0.02) from those of benign gliomas (3, n=9) but not from that of meningioma (11.9, n=4). The cut-off value for distinguishing malignant from benign lesions on the basis of E set at 4.8 resulted in sensitivity 67%, specificity 75%, accuracy 70%, positive predictive value 80% and negative predictive value 60%. D and R showed tendency of wash-out of MIBI from meningiomas, but otherwise did not improve the results substantially. ConclusionIntegrated results of RCA and SPET with 99mTc-MIBI indicate that blood perfusion, blood–tumour barrier permeability and metabolic activity of the tumour are all very important for the resultant uptake shown by SPET. If the perfusion index is less than 1.45, then meningioma can be ruled out. Early SPET is recommendable for distinguishing glioblastoma from low-grade gliomas, as a complement to standard magnetic resonance imaging and/or computed tomography.

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.

Tc-99m labeled RBC scintigraphy of an inflammatory pseudotumor of the spleen.

Inflammatory pseudotumors are very rare benign lesions of an unknown etiology usually discovered accidentally. We present a 26-year-old woman with a nodal lesion discovered in the spleen during a routine check-up by abdominal ultrasound. Radiocolloid and delayed Tc-99m RBC scintigraphy proved the existence of a delineated hypervascular lesion. Histology and immunohistochemistry of the lesion proved an inflammatory pseudotumor, with very dilated sinusoids with blood congestion. The exact diagnosis of inflammatory pseudotumor can be established only by histology and/or immunohistochemistry of the spleen.

Validation of IAEA software package for the analysis of scintigraphic renal dynamic studies: parameters of renal transit in children with renal pelvic dilatation.

Purpose The objectives of the study were to use the International Atomic Energy Agency (IAEA) software package for the analysis of scintigraphic renal dynamic studies to obtain values of curve parameters and excretory parameters in children with hydronephrosis and to validate the reliability of these numerical outputs by comparing with values established by consensus reports. Patients and Methods Fifty children with hydronephrosis (median age, 16 months; 30 boys, 20 girls; 99 kidneys) underwent 99mTc-MAG3 diuresis renography. Studies were analyzed by 2 observers, and according to the assessment of images, renograms, and differential function, kidneys were classified as normal (42, kidneys contralateral to hydronephrotic kidney), hypotonic unobstructed (49), and obstructed (8). The IAEA software was applied to each renogram. The parameters analyzed were as follows: normalized residual activity at 20 minutes (NORA 20) and on postmicturition (PM) acquisition, output efficiency at 20 minute (OE 20), PM to maximum renal count ratio (PM/max), and mean transit time (MTT). Results Mean values for normal, hypotonic unobstructed, and obstructed kidneys were as follows: NORA 20: 0.25, 0.57, and 2.16; OE 20 (%): 94.5, 87, and 57; normalized residual activity on PM acquisition: 0.02, 0.03, and 0.27; PM/max: 0.01, 0.02, and 0.13; and MTT (minutes): 1.9, 3.5, and 8.9, respectively. Difference between obstruction/dilatation and normal/dilatation was significant (P < 0.0001), as well as the correlation between NORA 20/OE 20 (R = −0.982). Cutoff values to predict obstruction were as follows: NORA 20, 1.6; OE 20, 73%; NORA PM, 0.11; PM/max, 0.06; and MTT, 8.23 minutes. Conclusions The IAEA software package gives reliable values of numerical parameters of renal excretion. The use of the software improves diagnostic accuracy of diuresis renography in children.

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]