Validation of numerical outputs of IAEA software by the analysis of diuretic nephrogram in children with antenatally detected hydronephrosis.

UNLABELLED: Diuretic nephrogram is important diagnostic tool in the postnatal follow-up of asymptomatic antenatally detected hydronephrosis (HN). In the last decades, two quantitative indices of renal excretion, output efficiency and the residual kidney counts normalized to the 1-2min counts (normalized residual activity, NORA) have been proposed, that enhance the accuracy of technique to detect kidneys with obstruction. Unfortunately, in many nuclear medicine departments in developing countries the obsolete computer systems do not give the opportunity of sophisticated analysis of nephrogram. Almost a decade ago, the Nuclear Medicine Section of the International Atomic Energy Agency (IAEA) has developed non-commercial software for nephrogram processing on a simple p-computer, which allows access to the developments in this field. However, till now, the software has not been widely implemented in the nuclear medicine institutions in developing countries. Furthermore, the accuracy of numerical outputs of the software has not been assessed in comparison with commercial software. The aims of this study in children were: a) to calculate, by means of the International Atomic Energy Agency (IAEA) software, the values of the technetium-99m mercapto-acetyl-triglycine ((99m)Tc MAG3) parameters in three categories of kidneys: normal kidneys, obstructed kidneys and hypotonic unobstructed kidneys and b) to assess the accuracy of the obtained numerical parameters by comparing with the values published by other authors. Investigation was carried out on a sample of 62 children: 43 boys and 19 girls (median age: 16 months) with antenatally detected HN attributed to pelviureteric junction (PUJ) stenosis. Neither of kidneys had undergone pyeloplasty prior to our investigation. 130 nephrogram curves were analyzed. 22-minutes acquisition with 132 10sec images was applied. Furosemide was administered after 2min (F+2). Post-void static image was acquired at 60min. Two observers analyzed each study and classified kidneys into three categories. Group 1: 84 kidneys contralateral to hydronephrotic kidney, without structural abnormality on previous diagnostics; Group 2: 30 hypotonic non-obstructed kidneys; Group 3: 16 obstructed kidneys. Parameters analyzed were: output efficiency (OE), residual kidney counts at 20min normalized to the 1-2min counts (NORA20) and residual kidney counts on post-micturition acquisition normalized to the 1-2min counts (NORAPM). Results were presented as mean±SD. For group 1 they were: OE: 95±1.5%; NORA20: 0.25±0.06; NORAPM: 0.02±0.007. Results for group 2 were: OE: 87±7.8%; NORA20: 0.57±0.19; NORAPM: 0.03±0.02. For group 3: OE: 56±9.6%; NORA20: 2.16±0.33; NORAPM: 0.27±0.13. Linear regression analysis showed significant inverse linear correlation between NORA20 and ROE20 (R=-0.982; y=99.6-21.1x) at 0.01 level. ROC analysis revealed cutoff values of predicting obstruction at 71%, 1.62 and 0.11 for OE, NORA20 and NORAPM, respectively. CONCLUSION: We have calculated in children by means of the IAEA software the values of three advanced parameters of the (99m)Tc MAG3 F+2 diuresis nephrogram for normal kidneys, hypotonic non-obstructed and obstructed kidneys. The overall results provided evidence of excellent agreement of obtained results with previously reported values of the quantitative parameters of renal washout. The parameters of IAEA software has been shown to be reliable in assessing kidney drainage. The nuclear medicine section of the IAEA should be encouraged to produce final version of the software and to release it through IAEA Web site.

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

PURPOSE OF THE REPORT: The 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 METHODS: The 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. RESULTS: Perfusion 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. CONCLUSIONS: Early 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.

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.

Radioimmunoscintigraphy of colorectal carcinomas with 99mTc-labelled antibodies.

BACKGROUND/AIMS: The aim of the study was the evaluation of the clinical validity of immunoscintigraphy with 99mTc labeled antibodies for the detection of metastases and recurrences of colorectal carcinomas. METHODOLOGY: We examined 17 patients with colorectal carcinomas. Scintigraphy was performed with anti-CEA MoAb 99mTc-BW 431/26. RESULTS: Recurrences of carcinomas were detected and confirmed by surgery in 6 patients, recurrences with liver metastasis in 5 patients, and only liver metastases in 3 patients. Planar immunoscintigraphy was positive in 5/8 patients with liver metastases and 8/11 patients with recurrences, whereas in 1/8 liver metastases and 3/11 recurrences were detected only by tomography. In two patients with metastases in the abdominal lymph nodes immunoscintigraphic findings both on planar scintigraphy and tomoscintigraphy were false negative. CONCLUSIONS: Immunoscintigraphy with 99mTc labeled antibodies can be useful in the diagnosis of recurrences and metastases of colorectal carcinoma, viability assessment after radiotherapy and in the choice of the adequate surgical treatment.

Usefulness of gated SPECT myocardial imaging in evaluation of patients with inferior myocardial infarction.

OBJECTIVE: Gated single photon emission computed tomography (gated SPECT) myocardial imaging gives useful information about the extent and severity of perfusion abnormalities (PA) and global left ventricular (LV) function in patients with coronary artery disease. The aim of this study was to evaluate by gated SPECT myocardial imaging differences in perfusion scores and LV function between stress and rest in patients with mild left ventricular dysfunction and/or normal function and previous inferior myocardial infarction (IMI) and to detect myocardial stunning. MATERIALS AND METHODS: The study included 77 patients (age 53 ± 8.21) with mild left ventricular dysfunction and previous IMI divided into two groups. Group 1 consisted of 34 patients with IMI and additional ischemia on perfusion scan and group 2 with 43 patients with previous IMI without ischemia on perfusion scan. All patients underwent a 2-day stress-rest gated SPECT myocardial imaging protocol with 99m technetium-methoxyisobutylisonitrile ((99m)Tc-MIBI). RESULTS: There was a more significant post-stress to rest decrease in ejection fraction (EFps) in patients with IMI and additional ischemia (group 1) than in patients with IMI (group 2) (-1.5 ± 2.5 vs. 1.5 ± 2.3, p < 0.001). In group 1, there was a significant increase in post-stress end-systolic volume (ESVps) in comparison to ESVr (70.4 ± 29.8 vs. 66.2 ± 26.2 ml, p = 0.044). However, the decrease in EF post-stress to rest did not reach the level of significance (51.7 ± 10.8 vs. 53.2 ± 10.2%, p = 0.147). The extent and severity of perfusion abnormalities were higher on stress (SSS) than on rest images (SRS) (13.9 ± 8.6 vs. 8.3 ± 7.8, p < 0.001). There was no difference in global LV parameters or perfusion abnormalities in patients in group 2 between stress and rest except for a significant increase in the post-stress EF to rest value (57.9 ± 11.9 vs. 56.2 ± 10.5%, p = 0.018). Severe decrease of post-stress EF to rest was found in 12 (16%) patients indicating stunning. CONCLUSION: In patients with mild left ventricular dysfunction and IMI with additional ischemia there is evidence of a decrease in the post-stress EF with an increase in the post-stress ESV. In addition, a significant association between the decrease of post-stress EF with the extent and severity of perfusion abnormalities was detected. Gated SPECT myocardial imaging has an important role in the evaluation of perfusion and LV function in patients with IMI especially in patients with additional ischemia.

Relationship between Helicobacter pylori infection estimated by 14C-urea breath test and gender, blood groups and Rhesus factor.

The aim of this study was the detection of helicobacter pylori (HP) infection and estimation of this infection relationship with age, gender, blood groups and Rhesus factor, as well as the assessment of the accuracy of the method. A total of 227 patients with gastritis were examined. Blood ABO groups and Rh positivity were determined using standard tests. Infection by HP was proved by (14)C-urea breath test and gastric biopsy. Patients were aged 20-81 years (X=51.7 years) and the presence of HP was not related to the age (P>0.05). From the total number of patients, 25/69 males and 68/158 females were HP positive. There was no significant difference between genders and HP infection (P>0.05). From the 227 investigated patients, 69 (30%) belonged to blood group O, 96 (42%) to A, 40 (18%) to B and 22 (10%) to AB. HP was detected in 27/69 patients with blood group O, 45/96 patients with blood group A, 16/40 patients with blood group B and 5/22 patients with blood group AB. There was no statistically significant difference (P>0.05) in the incidence of HP infection between these groups (proving that HP infection did not depend upon the blood groups). Also, there was no significant correlation between the presence of particular blood group in HP+ patients related to the reported frequency of the blood groups in Serbian population (0--38%, A--42%, B--15%, AB--5%). HP was found in 16/36 Rh- and in 77/191 Rh+ patients without statistical difference (P>0.05). Also, there was no significant correlation of the presence of the Rh factor in the HP positive patients to the frequency of the Rh factor in the Serbian population (84% Rh+ and 16% Rh-). The basic value of the HP+ test was slightly, but not significantly lower in comparison to the HP- patients (P>0.05). On the contrary, test values showed a highly significant difference (P<0.01) in HP+ and HP- patients. In conclusion, in adults HP infection does not depend upon the patient's age, gender, blood group type or Rh factor. In clinical terms, there were 93 true positive (TP), 129 true negative (TN), 5 false negative (FN) and 0 false positive (FP) patients. Sensitivity of the method was 94.9%, specificity 100%, positive predictive value 100%, negative predictive value 96.3% and accuracy 97.8%.

Diagnostic role of initial renal cortical scintigraphy in children with the first episode of acute pyelonephritis.

OBJECTIVE: Assessment of the first febrile urinary tract infection (UTI) in children has been the subject of debate for many years. Diagnosis of acute pyelonephritis (APN) is usually based on clinical and biological data. The clinical usefulness of early Tc-99m DMSA scintigraphy remains controversial, although it may influence the type and duration of treatment. The aim of this study was to assess the role of initial cortical scintigraphy in the detection of early renal parenchymal damage in children highly suspected of having APN and to compare the scintigraphic findings with selected clinical/laboratory parameters and ultrasonography. METHODS: A prospective study was conducted in 34 infants and young children (18 boys, 16 girls), aged 1.5-36 months (mean 9.8 ± 8.7 months), hospitalized with a first episode of clinically suspected APN. Within the first 5 days after admission, Tc-99m DMSA renal scintigraphy, ultrasonography (US), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), white blood cell count (WBC) and urine analyses were performed. RESULTS: DMSA scintigraphy showed changes consistent with APN in 27/34 (79%) patients, with a mean age of 10.9 months, including 12 males (44%) and 15 (56%) females. Out of 9 febrile children with negative urine culture and supportive evidence of UTI, scintigraphy showed parenchymal involvement in 8 children (24% in the whole group, 30% in scintigraphically documented APN). There were no statistically significant correlations between the frequency or size of the initial scintigraphic abnormalities and age, sex, body temperature, CRP levels or ESR. A CRP level of >54 mg/L and a WBC of >13,300/mm³ had sensitivities of 56 and 59% and specificities of 86 and 71%, respectively. US showed changes consistent with APN in 7/34 (21%) in the whole group and in 7/27 (26%) patients with positive cortical scan (p < 0.05). CONCLUSION: Initial DMSA renal scintigraphy is a sensitive method for the early diagnosis of APN in young children and is useful in the assessment of the severity of kidney injury even in patients with negative urine culture. Clinical, biological and ultrasound parameters do not identify children with renal damage. Normal DMSA study, excluding parenchymal involvement and late sequelae, could minimize the use of scintigraphy in the follow-up and reduce the redundancy of cystography.

[Cytological findings in scintigraphically nonfunctioning thyroid nodules].

BACKGROUND/AIM: The major one among the procedures for evaluating changes in the thyroid nodules is fine needle aspiration biopsy (FNAB). Thyroid scintigraphy is commonly used in diagnostic algorithm of nodules. Less than 5% of examined nodules show to be malignant. Scintigraphically, nodules could be classified as functional and nonfunctional. It is estimated that the risk of malignancy in nonfunctional nodules ranges from 8% to 25% and more. Aspiration punction provides 100% specific and positive predictive value. The aim of the study was to establish the distribution of cytological findings in nonfunctioning thyroid nodules. METHODS: The prospective study enrolled 112 patients, 104 women and 8 men, submitted to thyroid scintigraphy for known thyroid nodule disorder. Scintigraphy was performed about half an hour after iv administration of 74 MBq of sodium-pertehnetate. A pin hole collimator was used. Scintigrams were visually evaluated, and absence of radiopharmaceutic in a nodule was estimated as nonfunctional one. Such nodules were afterwards subjected to FNAB and material obtained was cytologically analyzed. RESULTS: In our patients nonfunctioning nodules comprised tissue of colloid struma, thyroid cyst, regular thyroid tissue, follicular lesion, oxiphillic lesion, papillary carcinoma tissue and tissue of lymphocytic thyroiditis. The most frequent cytological finding were colloid cysts (52%). A total of 70% were female nodules. Five cytological findings were histopathologically analyzed. CONCLUSION: Cytological finding of nonfunctional nodules determines of the decision on radical therapy, and our preliminary results imply the need of FNAB routine use in nuclear medicine practice.

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 Tc-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. METHODS: Fifty 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. RESULTS: Mean 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. CONCLUSION: Integrated results of RCA and SPET with Tc-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.

Detection of gastrointestinal and abdominal infections by 99mTc-antigranulocyte antibodies.

BACKGROUND/AIMS: The aim of the study was detection of abdominal infections by 99mTc- antigranulocyte antibodies. METHODOLOGY: Total of 36 patients with clinical suspicion on abdominal or gastrointestinal infections was investigated. RESULTS: There were 23 true positive (TP) findings (one pulmonary abscess, 2 subhepatic abscesses after surgery, 2 perianal fistula, 2 chronic and 4 acute appendicitis, 5 abdominal and 3 pelvic abscesses, 3 M. Crohn, one ulcerative colitis), 9 true negative (TN) (3 tumors of the coecum, 2 tumors of papilla Wateri, 2 gastric carcinoma, 2 colon carcinoma), and 4 false negative (FN) (2 abscesses subphrenic and 2 enterocolic fistula). False positive (FP) findings were not observed. The smallest lesion found was 19x18 mm. SPECT increased the number of TP findings from 17 to 23. Fifteen of 23 infectious of inflammatory lesions could be detected in the early scan. Sensitivity was 85%, specificity 100%, positive predictive value 100%, negative predictive value 69% and accuracy 89%. CONCLUSION: According to the present results, scintigraphy with 99mTc antigranulocyte antibodies is a useful method for detection and assessment of exact localization abdominal infections, which is very important for the prompt and appropriate therapy.

Clinical investigations of 99mTc-p-aminohippuric acid as a new renal agent.

OBJECTIVE: 99mTc-p-aminohippuric acid (PAH) is a new radiopharmaceutical rapidly secreted by the kidneys in a manner consistent with tubular secretion. A comparative study of renal scintigraphy and clearance with 99mTc-PAH, diethylene triamine pentaacetic acid (DTPA) and mercaptoacetyltriglycine (MAG,) was performed. METHODS: 99mTc-PAH was prepared from a lyophilized kit by addition of sodium pertechnetate in the presence of DTPA. Ten healthy individuals were injected with 110 MBq of 99mTc-PAH. A dynamic study was repeated with 99mTc-DTPA and 99mTc-MAG3 several days later, after a 1-day interval. Clearance measurements were performed in five individuals. RESULTS: The mean values of time-to-peak activity (Tmax) and the time from peak to 50% of peak activity (T(1/2)) for 99mTc-PAH (3.6 +/- 0.9 and 6.9 +/- 2.7 min, respectively) and 99mTc-MAG3 (3.5 +/- 0.8 and 6.8 +/- 2.1 min, respectively) were significantly lower in comparison with those of s99mTc-DTPA (4.9 1.7 and 11.7 +/- 1.9 min, respectively). The mean value of 99mTc-PAH clearance (186.9 +/- 12.2 ml/min) was significantly lower in comparison with MAG3 clearance (303.9 +/- 19.5 ml/min) and significantly higher than DTPA clearance (85.0 +/- 24.1 ml/min). CONCLUSION: Our preliminary results indicate the potential usefulness of 99mTc-PAH for routine renal scintigraphy. Owing to its fast kinetics, excretion properties and high-quality images, it could be a suitable substitute for 99mTc-DTPA. 99mTC-PAH clearance values, however, were significantly lower than those of MAG3, and could not be used for the estimation of renal plasma flow.

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.

OBJECTIVES: We 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). METHODS: Eighty-eight patients with a history (> or =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. RESULTS: Patients 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. CONCLUSION: In 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.

[Variability in interpretation of static renal scintigraphy findings].

BACKGROUND: Static renal scintigraphy with 99mTc-DMSA is a sensitive method for evaluation of any reduction of cortical mass function. There is not enough reliable references in the literature on scintigraphic reports in terms of objectivity and standardization. The aim of this paper was to assess the differences in interpretation of routine renal scintigraphic findings by nuclear medicine specialists from various institutions (interobserver variability). METHODS: Both interobserver variability and agreement in the interpretation were evaluated in two groups. Six observers from four different institutions (group A), and three observers from the same institution (group B) interpreted independently 60 static renal scintigraphy findings obtained by analogous imaging using x-ray films in four standard projections. Using at least two options, seven parameters of renal scintigraphy protocols were analysed: size (1), uptake (2), outlines (3), scars (4), focal changes (5), relative function (6), and conclusions (7). RESULTS: The interpretations of scintigraphic findings were in accordance in items 1 to 7 within the group A: 62, 42.5, 45, 9, 47, 52, and 34 percent respectively, and within the group B: 72, 55, 59, 22, 62, 60, and 41 percent, respectively. The conformity was more significant in the findings observed in group B as opposed to group A, which was statistically highly significant, especially for the category of scars (p < 0.01). Significant variability was also observed by six observers in all the parameters of scintigraphic protocol, especially, again, in the scars analysis (p < 0.01). CONCLUSION: Insignificant degree of accordance, especially in the assessment of scars necessitates the standardization of criteria and terminology in order to interprete the renal scintigraphy with more accuracy and objectivity.

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 recipient's 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.

Measurement of renal function by calculation of fractional uptake of technetium-99m dimercaptosuccinic acid.

BACKGROUND: The purpose of this study was to set up normal values of the fractional uptake (FU) of technetium-99m dimercaptosuccinic acid in adults and in the pediatric population, as well as to evaluate the validity of this parameter at different levels of renal function. MATERIAL AND METHODS: A total of 86 subjects was divided into seven groups. In group A there were 23 potential kidney donors and in group B, 18 children in remission after a first urinary tract infection. Another three groups consisted of patients with diabetes i.e. group C, seven patients with normal values of albuminuria, group D, 16 patients with microalbuminuria and group E, five patients with macroalbuminuria. In group F, there were ten patients with a well-functioning transplanted kidney and in group G, seven patients with suspected acute rejection. The procedure began with the quantification of the doses of 99mTc-DMSA to be injected and the measurement of the empty syringe lying on the gamma camera collimator. Thereafter, four planar views of the kidneys were acquired three hours after the injection. The counts from the posterior and anterior views were subtracted for background and corrected for radioactive decay time and patient thickness. The FU was calculated by the geometric mean of counts per second from the posterior and anterior view. It was expressed as a fraction of the injected dose. RESULTS: The mean values of FU in healthy adults were 0.227 +/- 0.077 for one kidney and 0.454 +/- 0.146 for both kidneys. The mean values of FU for the left and right kidney were 0.225 +/- +/- 0.071 and 0.229 +/- 0.079, respectively. In children, the mean values were 0.220 +/- 0.092 for one kidney and 0.432 +/- 0.094 for both kidneys. The highest values of FU of 0.322 +/- 0.078 (0.644 +/- 0.138 for both kidneys) were measured in group C. In group D, FU was 0.185 +/- 0.065 (0.361 +/- 0.125 for both kidneys) and in group E 0.082 +/- 0.040 (0.163 +/- 0.080 total). In patients with a transplanted kidney, fractional uptake was 0.162 +/- +/- 0.039 in group F and 0.065 +/- 0.021 in group G. There was no significant difference in the values of FU between healthy adults and children. The uptake in group C was 41% higher than in group A and the difference was statistically significant. In groups D and E, the uptake was significantly lower than in A. In both groups of patients with transplanted kidneys, the uptake was significantly lower than in control group. The correlation between FU and biochemical parameters of renal function [blood urea nitrogen (BUN), serum creatinine (Cr) and creatinine clearance (CCr)] was significant: FU/BUN r = -0.86; FU/Cr r = -0.77; FU/CCr r = 0.60. CONCLUSION: Fractional uptake of 99mTc-DMSA could serve as a sensitive parameter of renal function. The mean values of FU in adults were 0.454 and in children 0.432. There was no significant difference between values for the left and right kidney. In diabetes mellitus, fractional uptake correlated well with the degree of diabetic nephropathy. In patients with a well-functioning transplant, the uptake was slightly reduced. Low values of fractional uptake in acute rejection were related to lesions in kidney blood vessels and in tubular cells.