Dopamine transporter imaging (123)I-FP-CIT (DaTSCAN) SPET in differential diagnosis of dopa-responsive dystonia and young-onset Parkinson's disease.

Dopa-responsive dystonia (DRD) is a genetic disorder characterized by childhood onset dystonia, dominant inheritance, diurnal symptoms fluctuation and positive levodopa response. Adult-onset DRD is frequently combined with parkinsonism and can be mistaken with young onset Parkinson's disease (YOPD). Both conditions are caused by dopamine deficiency, due to nigral cells' loss in YOPD, and due to enzymatic defects in dopamine synthesis in DRD. Single photon emission tomography (SPET) with (123)I-N--fluoropropyl-2b-carbomethoxy-3b-(4-iodophenyl) nortropane ((123)I-FP-CIT)-DaTSCAN is a sensitive neuroimaging method for the assessment of nigrostriatal dopaminergic system integrity and degeneration. Our aim was to evaluate the usefulness of (123)I-FP-CIT( DaTSCAN) SPET in the differential diagnosis of DRD and YOPD in clinical practice. Brain SPET with (123)I-FP-CIT was performed in 13 patients (7 males, 6 females), age 20-58 years, with mean age of onset of their disease, 29 years, eleven patients with early onset parkinsonian symptoms and 2 with genetically proved DRD. The images were evaluated by visual and semiquantitative analyses (ROI). The ratio of specific-striatal to non specific-occipital binding was calculated. Ten out of 11 patients with YOPD had decreased accumulation of DaTSCAN in striatum, especially in putamen, that is typical findings for Parkinson's disease. In three patients DaTSCAN was normal with symmetric tracer uptake in both striata, caudate nucleus and putamen and the diagnosis of DRD was suspected. Two patients with initial dystonic symptoms and genetically proved DRD had normal DaTSCAN. In one patient after normal DaTSCAN findings the initial diagnosis of YOPD was changed to the diagnosis of DRD. Region of interest (ROI) analyses have shown significantly lower(123)I-FP-CIT binding ratios in YOPD than in DRD in all 3 regions of interest: striatum (1.95±0.32) vs (2.76±0.10) P<0.001, putamen (1.76±0.25) vs (2.84±0.14) P<0.0001 and caudate nucleus (2.37±0.51) vs (3.27±0.14) P<0.01. In conclusion, our results indicate that DaTSCAN is an objective neuroimaging method able to distinguisch neurodegenerative disease YOPD from DRD and clarify a clinical dilemma, which is important for the treatment, prognosis and genetic counseling of patients and their families.

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.

The diagnostic role of gated myocardial perfusion imaging and radionuclide ventriculography in severe congenital heart disease.

Several techniques have been applied for the assessment of severe congenital heart diseases (SCHD) including echocardiography, cardiac catheterization with angiocardiography, and more recently, cardiovascular multi detector tomography and magnetic resonance imaging (MRI). The value of gated single photon emission tomography (GSPET) myocardial perfusion imaging (MPI) and radionuclide ventriculography (RNV) for evaluating myocardial ischemia, tissue viability, and left ventricular function in SCHD is less apparent. The risk of radiation exposure is greatest in the youngest patients. Both, GSPET MPI and RNV seem to be underutilized in pediatric clinical practice due to increased radiation exposure. We have reviewed basic and specific technical and diagnostic aspects, as well as specific clinical indications of GSPET MPI and RNV in children with SCHD in comparison with other cardiology methods. Some of our own tests are also presented where they apply. In conclusion, GSPET MPI and RNV can provide clinical relevant information of functional significance of SCHD in pediatric patients especially when the other cardiology methods are indeterminate. With regard to radiation exposure appropriate patient selection and recommendations for reduction of radiation exposure are of great importance.

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%.

Fractional flow reserve and myocardial viability as assessed by SPECT perfusion scintigraphy in patients with prior myocardial infarction.

BACKGROUND: In patients with previous myocardial infarction (MI), assessment of myocardial viability and physiological significance of coronary artery stenoses are essential for appropriate guidance of revascularization. The aim of the study was to evaluate the relation between fractional flow reserve (FFR) and myocardial viability as assessed by gated SPECT MIBI perfusion scintigraphy in patients with previous MI undergoing elective PCI. METHODS: The study population consisted of 26 patients (mean age 55 ± 7 years; 21 male) with a previous MI and a significant coronary stenosis in a single infarct-related coronary vessel for which PCI was being performed. In all patients, FFR was evaluated before and immediately after PCI. SPECT imaging was done before and 3 ± 1 months after PCI. A region representing the MI was considered viable if MIBI uptake was ≥55% of the normal region. Improvement in perfusion after revascularization was considered achieved if perfusion abnormalities decreased by 5% or more and there was a decrease in segmental score of ≥1 in three segments in PCI-related vascular territory. RESULTS: Extent of perfusion abnormalities decreased from 32 ± 16% to 27 ± 19% after PCI (P < .001). In patients with myocardial viability in comparison to patients with no viability, there was significant difference in FFR before PCI (.57 ± .14 vs .76 ± .12, P = .002), despite almost the same values of diameter stenosis of infarct-related artery (63 ± 8% vs 64 ± 3%, respectively, P = .572). In addition, FFR prior to PCI was related to improvement in perfusion abnormalities after revascularization (P = .047), as well as with peak activity of creatine-kinase measured during previous MI (r = .56, P = .005). CONCLUSION: Lower values of FFR before angioplasty are associated with myocardial viability and functional improvement as assessed by SPECT perfusion scintigraphy.

One-year follow-up of myocardial perfusion and function evaluated by gated SPECT MIBI in patients with earlier myocardial infarction and chronic total occlusion.

OBJECTIVE: Optimal treatment for chronic total occlusion (CTO) in the infarct-related coronary artery is not clear. Our aim was to assess myocardial perfusion, left ventricular ejection fraction (EF), and left ventricular size using gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging with 99mTc-methoxy-isobutyl-isonitrile in patients with CTO before and 1 year after recanalization. METHODS: Thirty patients with earlier myocardial infarction and at least one CTO underwent percutaneous coronary intervention (PCI) as well as nitrate-enhanced gated SPECT myocardial perfusion and dobutamine stress echocardiography before and 11 +/- 1 months after recanalization. They were divided into three groups based on the outcome of the follow-up angiography: (i) successful recanalization with no evidence of in-stent restenosis (n=13); (ii) successful recanalization with in-stent restenosis (n=7) and (iii) unsuccessful recanalization (n=10). RESULTS: Overall success of recanalization for CTO was 74%. In group 1, myocardial viability was preserved in 11 of 13 (85%) patients at baseline. Gated SPECT at 1 year showed a significant decrease in perfusion abnormalities (29 +/- 12 to 23 +/- 14%, P < 0.05) and left ventricular end-diastolic volume (EDV) (168 +/- 47 to 151 +/- 47 ml, P < 0.05). Improvement in EF (51 +/- 11 to 54 +/- 13%, P > 0.05) and reduction in left ventricular end-systolic volume (ESV) (84 +/- 37 to 77 +/- 40 ml, P > 0.05) did not reach the level of significance. Myocardial viability was preserved in only two of seven patients (28%) in group 2. Neither mean perfusion abnormalities (37 +/- 24 to 35 +/- 22%, P > 0.05) nor global left ventricular parameters (EF 41 +/- 15 vs. 42 +/- 19%, EDV 298 +/- 33 vs. 299 +/- 57 mL, ESV 197 +/- 12 vs. 195 +/- 32 ml; P > 0.05) changed at the follow-up. In group 3, myocardial viability was preserved in seven of 10 patients (70%) at baseline, but no significant changes in perfusion (40 +/- 18 vs. 41 +/- 19%, P > 0.05) and left ventricular function (EF 42 +/- 17 vs. 44 +/- 14%, EDV 228 +/- 101 vs. 227 +/- 81 ml, ESV 143 +/- 87 vs. 146 +/- 8 ml; P > 0.05) were seen at the follow-up. CONCLUSION: Myocardial perfusion and EDV may significantly improve 1 year after PCI provided recanalization of CTO was successful. Our preliminary findings suggest that successful recanalization of CTO may have favorable outcome on left ventricular perfusion and function, particularly in patients with viable myocardium before PCI. The gated SPECT myocardial perfusion imaging with 99mTc-methoxy-isobutyl-isonitrile may be useful for monitoring long-term functional outcome of PCI in patients with CTO.

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.

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.

Assessment of non-small cell lung cancer viability and necrosis with three radiopharmaceuticals.

UNLABELLED: Assessment of tumor viability and necrosis of non-small cell lung cancer and detection of distant metastases are important for diagnosis, staging, monitoring the response to treatment and planning long-term management. We performed scintigraphy on patients with non-small cell lung cancer to determine the utility of three tumor targeting tracers for diagnosing primary lung cancer, for differentiating viable from necrotic tumor tissue and for detecting distant bone and soft tissue metastases. Our patients were divided into groups. Group A consisted of 27 patients, 25 male and 2 female, mean age 59 years, range from 35 to 72 years. These patients underwent radioimmunoscintigraphy (RIS) using monoclonal antibody against human milk fat globule labeled with technetium-99m ((99m)Tc). Group B consisted of 23 patients, 21 male and 2 female, mean age 56 years, range: 37 to 70 years. Group C consisted of 24 patients, 20 male and 4 female, mean age 58 years, range: 35 to 74 years. Both Groups B and C underwent chest and whole-body scintigraphy with 555 MBq of (99m)Tc-sestamibi ((99m)Tc-S) and 111 MBq of thallium-201 chloride ((201)TlCl), respectively. Tumor to non-tumor ratio was calculated. Our findings show that RIS had 52% sensitivity in detecting primary non-small cell lung cancer. In contrast, the sensitivity of (99m)Tc-S and of (201)Tl scintigraphy was 87% and 88%, respectively. High uptake of all three radiopharmaceuticals was found in 6 patients with distant soft tissue and bone tissue metastases and in 1 patient with brain metastasis. Mean tumor to non-tumor ratios were similar: for RIS 1.7+/-0.4, for (99m)Tc-S 1.6+/-0.3 and for (201)Tl 1.6+/-0.2. IN CONCLUSION: (99m)Tc-S and (201)Tl scintigraphy are superior to RIS for detecting non-small primary lung cancers and potentially clinically useful methods for detecting primary lung cancer as above, as well as bone and soft tissue metastases.

111In-platelets dynamic study in chronic immune thrombocytopenic purpura.

BACKGROUND: The aim of this work was to estimate the significance of a dynamic study performed during the first 20 minutes after autologous (111)In-oxinate-platelets injection in patients with chronic immune thrombocytopenic purpura (ITP). Two hypotheses were tested: a) dynamic study indicates the place of platelet sequestration; b) dynamic study reflects the quality of platelet separation and labelling procedure. MATERIAL AND METHODS: Thirty-nine persons were investigated: 25 with shortened platelet life span (ITP), and 14 with normal platelet life span (6 healthy subjects and eight patients with myelodysplastic syndrome--MDS). Platelet blood count on the day of platelet labelling, general yield of platelet labelling (GYL), differential yield of platelet labelling (DYL), platelet life span, dynamic study with initial platelet accumulation in the liver (IPAL), sequential static study for determining the platelet sequestration index (SI) and platelet sequestration site (SS) were investigated. RESULTS: Two types of labelled platelet kinetics were determined in both groups of patients: IPAL < 20% and IPAL > 20%. A statistically significant difference in GYL and DYL was noted between the patients with IPAL < 20% and IPAL > 20%. No significant difference was registered in platelet blood count, life span, SS and SI between the two groups of patients. Both yields of platelet labelling were higher in the group with IPAL < 20%. There was no correlation between IPAL and platelet SI, or between IPAL and platelet SS. CONCLUSIONS: Dynamic study with (111)In-platelets cannot predict platelet sequestration site in ITP patients, but it is a useful and sensitive method of platelet labelling procedure quality control.

Clinical significance of optimal red cell mass and plasma volume estimation methods.

BACKGROUND: The aim of this study was to present and compare the results of proposed methods for optimal red cell mass and plasma volume (RCM&PV) estimation, and their influence on the interpretation of obtained results. MATERIAL AND METHODS: In 120/280 patients with polycythaemia rubra vera, subjected to RCM&PV determination with autologous erythrocytes in vitro labelled with 51Cr-sodium chromate, optimal volumes were determined using: 1. traditional ml/kg of: --the real body weight method (ml/kg RBW); --the optimal body weight method (ml/kg OBW). 2. the body weight, height, and sex based method (Retzlaff's tables), 3. the method recommended by the International Council for Standardization in Haematology (ICSH), based on body surface area. RESULTS: Different interpretation of the same results of 120 RCM&PV measurements was registered in 48/120 patients (40%). The greatest disagreement existed between ml/kg RBW and ml/kg OBW methods (in 39/120 subjects, 32.5%). In underweight patients the ml/kg RBW method, and in overweight patients the ml/kg OBW method, offered better agreement with ICSH&Retzlaff's methods. The ml/kg RBW method disagreed with ICSH&Retzlaff's methods and ml/kg OBW in 25% and 19.2% of patients respectively. ICSH and Retzlaff's methods disagreed in 10/120 patients (8.3%). The ICSH method yielded significantly lower optimal volumes than Retzlaff's. CONCLUSION: Three methods for optimal RCM&PV estimation lead to different interpretations of the same results of RCM&PV measurements with 51Cr-erythrocytes in 40% of patients. Two ml/kg body weight methods show greater disagreement in comparison with ICSH and Retzlaff's methods, which differ significantly. The ICSH method yields lower optimal values compared to Retzlaff's.

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.

Responsiveness of FDG PET/CT to treatment of patients with active chronic sarcoidosis.

PURPOSE: This study aimed to compare baseline to follow-up 18F-FDG PET/CT findings after treatment for active chronic sarcoidosis and to correlate changes on 18F-FDG PET/CT with changes in clinical status. PATIENTS AND METHODS: The sample included 66 patients with chronic sarcoidosis and evidence of active inflammation on baseline F-FDG PET/CT for which they received therapy. Of these 66 patients, 30 returned for the follow-up 18F-FDG PET/CT after 12 (5) months to evaluate response to treatment. They were also asked to indicate changes in clinical status. Baseline characteristics of patients who did and did not return for the follow-up were compared to assess selection bias. RESULTS: SUVmax was significantly decreased at the follow-up compared with baseline 18F-FDG PET/CT (8.46 [3.52] vs 4.90 [0.96]; P = 0.006), primarily in the mediastinum. Inflammatory activity appeared absent in 9 patients, decreased in 12 patients, and increased in 9 patients, with the corresponding changes in SUVmax of -80%, -41%, and +54%, respectively. The changes on 18F-FDG PET/CT were in agreement with self-perceived changes in clinical symptoms (P = 0.019). The angiotensin-converting enzyme at the follow-up was not significantly different from baseline (49.80 [19.25] vs 46.35 [25.58], P = 0.522). There was no difference in baseline characteristics of patients who did and did not return for the follow-up. CONCLUSIONS: 18F-FDG PET/CT is able to detect clinically meaningful changes in magnitude and extent of inflammatory activity in patients receiving treatment for active chronic sarcoidosis. Thus, 18F-FDG PET/CT is a valuable adjunct to clinical evaluation for monitoring the response to treatment in these patients.

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.

The utility of 18F-FDG PET/CT for diagnosis and adjustment of therapy in patients with active chronic sarcoidosis.

UNLABELLED: The purpose of this study was to assess the utility of (18)F-FDG PET/CT for detection of inflammation in granulomatous sites and management of patients with chronic sarcoidosis. The 3 specific aims were to assess differences between (18)F-FDG PET/CT and multidetector CT (MDCT) findings, to compare (18)F-FDG PET/CT results with serum levels of angiotensin-converting enzyme (ACE), and to determine whether (18)F-FDG PET/CT findings are associated with the decision to change therapy. METHODS: We studied 90 sarcoidosis patients (mean age ± SD, 47 ± 12 y; 32 men and 58 women) with persistent symptoms who were referred for (18)F-FDG PET/CT evaluation to assess the extent of inflammation. They also underwent MDCT and measurement of serum ACE level. After the follow-up (12 ± 5 mo after (18)F-FDG PET/CT), the clinical status and changes in therapy were analyzed. RESULTS: (18)F-FDG PET/CT detected inflammation in 74 patients (82%) (maximum standardized uptake value, 8.1 ± 3.9). MDCT was positive for sarcoidosis in 6 additional patients (80, 89%). The difference between the 2 methods was not significant (P = 0.238, McNemar test), and their agreement was fair (κ = 0.198). Although ACE levels were significantly higher in patients with positive than negative (18)F-FDG PET/CT results (P = 0.002, Mann-Whitney test), 38 patients (51%) with positive (18)F-FDG PET/CT results had normal ACE levels. The therapy was initiated or changed in 73 out of 90 patients (81%). Both univariate and multivariate logistic regression analyses indicated that positive (18)F-FDG PET/CT results were significantly (P < 0.001) associated with changes in therapy, with no contribution from age, sex, ACE level, CT results, or previous therapy. CONCLUSION: Our results indicate that (18)F-FDG PET/CT is a useful adjunct to other diagnostic methods for detecting active inflammatory sites in chronic sarcoidosis patients with persistent symptoms, especially those with normal ACE levels. (18)F-FDG PET/CT proved advantageous for determining the spread of active disease throughout the body and influenced the decision to adjust the therapy.

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.

Preliminary experience with 18f-fluoro-deoxy-glucose positron emission tomography/computed tomography in pediatric oncology patients.

The aim of this study was to present preliminary experience with FDG PET/CT in pediatric oncology patients in National PET Center, Clinical Center of Serbia and to asses its impact on management of malignancies in children. 33 FDG PET/CT scans were performed on 30 pediatric patients. PET/CT imaging was performed for staging the disease, assessing therapy efficacy and diagnosing recurrent or metastatic disease. FDG PET/CT changed the stage of the disease in 60.6% (20/33) of the cases. 14 patients were down-staged after PET/CT, mostly patients with Hodgkin's disease, were in 7/10 cases PET/CT showed no activity in residual masses. Six scans led to upstage of the disease. In three cases PET/CT did not change the stage of disease, but has showed new distant metastases. In conclusion, FDG PET/CT showed important role in managing pediatric patients with different malignancies and was useful complementary diagnostic tool to conventional imaging methods.

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.

Possible role of the scintigraphic estimation of the relative liver perfusion in the diagnosis and therapy of liver carcinomas.

BACKGROUND: The aim of the study is evaluation of the possible role of the scintigraphic estimation of the relative liver perfusion in diagnosis and the choice of treatment of liver carcinomas. MATERIAL AND METHODS: Hepatic perfusion index was obtained by dynamic scintigraphy in 126 patients. RESULTS: In the control group values did not differ from the value in the patients with benign tumors (p > 0.05). However, in hepatocellular carcinoma and liver metastases of different tumors, HPI values were significantly decreased in comparison to controls and benign tumors (p < 0.01), but they didn't differ between themselves (p > 0.05). The values were especially low in the patients with malignant diseases in the liver accosciated with vascular disturbances in the portal system. CONCLUSION: HRA could be easily done during the different conventional nuclear medicine methods. It can be an useful method for the assessment of different degrees of hemodynamic alterations in portal system, for differential diagnosis of benign and malignant liver tumors, as well as for assessment of the liver tissue and tumor perfusion, which might be helpful in the decision making for the undertaking of intraarterial (radionuclide, chemotherapy etc.) therapy.

Comparative utility of gated myocardial perfusion imaging and transthoracic coronary flow reserve for the assessment of coronary artery disease in patients with left bundle branch block.

OBJECTIVES: To compare the diagnostic utility of gated single-photon emission computed tomography (SPECT) methoxy isobutyl isonitrile (MIBI) myocardial perfusion imaging and transthoracic Doppler echocardiography (TTDE) coronary flow reserve (CFR) to coronary angiography for detecting coronary artery disease (CAD) in patients with left bundle branch block (LBBB). METHOD: Forty-three patients with complete LBBB and an intermediate pretest probability for CAD underwent dipyridamole stress TTDE and gated SPECT MIBI during the same session and coronary angiography within a month. The parameters of myocardial perfusion (summed stress score, summed difference scores) regional wall function (wall motion score, wall thickening score) and ejection fraction were derived using the 17-segment model and 4D-MSPECT software. TTDE variables included peak flow velocity at rest and during hyperemia in left anterior descending artery (LAD), based on which CFR was calculated (normal>2). RESULTS: Perfusion ischemic scores were significantly higher in group 1 with angiographic evidence of greater than 50% LAD stenosis compared with group 2 with less than 50% LAD stenosis (summed stress score 12.4+/-5.5 vs. 8.3+/-3.5, P<0.05, summed difference score 3.7+/-1.2 vs. 1.1+/-0.3, P<0.01, respectively). Left ventricular regional wall function and ejection fraction were not different between the two groups. CFR was significantly lower in group 1 than in group 2 (1.65+/-0.21 vs. 2.31+/-0.28, P<0.001). Gated SPECT MIBI and CFR had similar sensitivity (88 vs. 88%), specificity (80 vs. 84%), and accuracy (84 vs. 86%) for detecting CAD in patients with LBBB. The agreement between the two methods was 85%. CONCLUSION: Our results show comparable diagnostic utility and high agreement between gated SPECT MIBI perfusion imaging and TTDE CFR assessment for detecting CAD in patients with LBBB. The advantage of gated SPECT MIBI over TTDE CFR measurements is the ability to assess the perfusion abnormalities in multiple vascular territories during the same procedure, which is convenient for detecting multi-vessel disease in patients with LBBB.