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.

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.

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 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.

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.

Evaluation of myocardial perfusion and function by gated single-photon emission computed tomography technetium-99m methoxyisobutylisonitrile in children and adolescents with severe congenital heart disease.

OBJECTIVES: The value of gated single-photon emission computed tomography technetium-99m methoxyisobutylisonitrile (gated SPECT (99m)Tc-MIBI) in children is not yet established probably because gated SPECT (99m)Tc-MIBI has rarely been used in pediatric clinical and research studies. The purpose of this study was to evaluate perfusion abnormalities and left ventricular (LV) function by gated SPECT (99m)Tc-MIBI in children and adolescents with severe congenital heart disease (CHD). METHODS: Seventeen children and adolescents with severe CHD (11 boys and six girls, mean age 11+/-4 years) underwent 2-day rest-stress (11 boys) or 1-day rest (six girls) gated SPECT (99m)Tc-MIBI. Myocardial perfusion was evaluated by a 17-segment model with a 5-point score to derive the summed stress score, the summed rest score (SRS), and the summed difference score based on the 4D-MSPECT software results. The extent of myocardial perfusion abnormalities was also expressed as a percentage of the LV size. The 4D-MSPECT software was used to calculate LV end-diastolic volume, end-systolic volume (ESV), and ejection fraction (EF). RESULTS: Reversible myocardial perfusion defect was found in 7 of 11 children (64%) who underwent rest-stress gated SPECT (99m)Tc-MIBI. The LV segments involved were anterior, anteroseptal, anterolateral, apical and inferior. These seven children showed significantly larger perfusion abnormalities on stress compared with rest study (18+/-5 vs. 7+/-4%, P<0.01) and higher summed stress score compared to SRS (11+/-4 vs. 4+/-2, P<0.01). Children and adolescents with myocardial ischemia had significantly lower poststress EF than rest EF (53+/-12 vs. 59+/-11%, P<0.05) and significantly higher poststress ESV than rest ESV (81+/-24 vs. 61+/-25 ml, P<0.05). In six children evaluated only at rest, perfusion defects involved anterior, anteroseptal and apical, or inferolateral segments, accounting for 31+/-12% of LV and with SRS of 12+/-5. Their global LV parameters were: end-diastolic volume 118+/-23 ml, ESV 56+/-16 ml, EF 51+/-10%. CONCLUSION: Poststress and rest-gated SPECT (99m)Tc-MIBI results indicate that children and adolescents with severe CHD show a range of abnormalities in myocardial perfusion and LV function, which is useful for determining functional importance of morphological malformations. Thus, gated SPECT (99m)Tc-MIBI provides complementary information that may guide clinical decision making in children and adolescents with severe CHD.

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.

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.

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.