[en] The introduction of non-invasive coronary angiography by multislice computed tomography (CT angiography), has changed the field of non-invasive cardiovascular imaging. The first CT angiography provides an overview of the anatomy of the coronary tree with a noninvasive modality. This allows the diagnosis of coronary heart disease (CHD) in earlier stages that the functional images, which has important diagnostic and prognostic implications. There have been numerous studies that show a high diagnostic accuracy of CT angiography in C D , is therefore increased application as gatekeeper for the application of other diagnostic techniques.The introduction of non-invasive coronary angiography by multislice computed tomography (CT angiography), has changed the field of non-invasive cardiovascular imaging. The first CT angiography provides an overview of the anatomy of the coronary tree with a non invasive modality. This allows the diagnosis of coronary heart disease (CHD) in earlier stages that the functional images , which has important diagnostic and prognostic implications. There have been numerous studies that show a high diagnostic accuracy of CT angiography in C D, is therefore increased application as gatekeeper for the application of other diagnostic techniques

[en] Aim: To compare post-stress and rest left ventricular ejection fraction (LVEF) in patients with no evidence of ischemic response during the stress test. This investigation was carried out in view of the few reports concerning the findings of ventricular function with gated SPECT in these situations in the normal population, which is relevant when considering the possibility of myocardial stunning. Material and Methods: We prospectively studied 59 selected patients, 33 men, ages 57±12 years referred for myocardial perfusion. In 24 cases (61±12 ys., 14 men) a dipyridamole (DIP) test was performed and in 35 cases (55±12 ys., 19 men) an exercise (EX) test was done. Inclusion criteria were: no previous history of myocardial infarction or revascularization, normal resting ECG, normal stress (DIP or EX) test results and no evidence of ischemia/scar in conventional myocardial perfusion tomograms. A two-day study protocol was carried out with injection of 925 MBq (25 mCi) of 99mTc-MIBI at stress and rest. Gated perfusion SPECT was acquired 45 to 60 minutes after radiotracer injection in both conditions and processed using QGSPECT software. Difference between stress and rest LVEF (delta LVEF) was calculated and student t-test applied to the data. Results: As shown in the table, rest LVEF was higher in the EX group, while no difference was found in stress LVEF between the two groups. Difference between stress and rest LVEF was not significant although a trend of the former to be higher was noted in both groups. Standard deviation of delta LVEF, however, shows that individual cases experienced a fall in ejection fraction in the post-stress period compared to the basal state both with DIP and EX. In fact, 2 patients in the DIP group (8%) and 6 patients in the EX group (17%) presented a negative delta LVEF greater than 10%. Conclusion: LVEF does not change significantly between post-stress and rest either using DIP or EX in populations with very low likelihood of coronary artery disease and a normal perfusion study. However, some patients presented lower post-stress LVEF despite no evidence of ischemic myocardial stunning. It has to be determined whether this finding represents some other mechanism of transient systolic dysfunction or reflects imperfect reproducibility of the method employed

[en] Use of organochlorine insecticides has been prohibited in Brazil since 1976. However, later use of existing stock and smuggled parcels are partially responsible for their incomplete elimination. Extended, official use of DDT took place over the entire country at the end of 1984 to eradicate malaria. In 1985, a cross-sectional survey was conducted for DDE at nine intertidal sites of All Saints Bay using local mussels. In 1994, the study was repeated in 19 sites utilizing four selected species of mussel and the same analytical methodology as previously applied. The DDT residues (as ng/g of DDE, wet weight) varied between 0.24 and 5.1 for Anomalocardia brasiliana, 2.1 and 44.0 for Brachidontes exustus, < 0.33 and 15.8 for Macoma constricta, and < 0.31 and 1.36 for Littorina spp. No samples were found that exceeded the various action limits. The highest concentrations were detected on the coastline of Salvador City, in the Aratu Industrial Centre area, in the Subae estuary and in the Itaparica channel. From 1985 to 1994, increases were observed at all the sites, except for Mataripe, where an oil refinery operates on a large restricted area. Increases of up to 15 fold were observed in the Salvador and Aratu areas. Prohibited use of DDT, together with the carry over of the DDT used in the malaria campaign, seem to be the reason for these increases. (author). 13 refs, 3 figs, 3 tabs

[en] Aim: To develop a procedure for the creation of nuclear medicine reports containing static and dynamic images. The reason for implementing this technique is the lack of adequate solutions for an electronic format of nuclear medicine results allowing for rapid transmission via e-mail, specially in the case of dynamic and gated SPECT studies, since functional data is best presented in dynamic mode. Material and Methods: Clinical images were acquired in static, whole body, dynamic and gated mode, corresponding to bone studies, diuretic renogram, radionuclide cystography and gated perfusion SPECT, as well as respective time-activity curves. Image files were imported from a dedicated nuclear medicine computer system (Elscint XPert) to a Windows-based PC through a standard ethernet network with TCP-IP communications protocol, using a software developed by us which permits the conversion from the manufacturer's original format into a bitmap format (.bmp) compatible with commercially available PC software. For cardiac perfusion studies, background was subtracted prior to transferring to reduce the amount of information in the file; this was not done for other type of studies because useful data could be eliminated. Dynamic images were then processed using commercial software to create animated files and stored in .gif format. Static images were re-sized and stored in .jpg format. Original color or gray scale was always preserved. All the graphic material was then merged with a previously prepared report text using HTML format. The report also contained reference diagrams to facilitate interpretation. The whole report was then compressed into a self-extractable file, ready to be sent by electronic mail. Reception of the material was visually checked for data integrity including image quality by two experienced nuclear medicine physicians. Results: The report presented allows for simultaneous visualization of the text, diagrams and images either static, dynamic, gated or time-activity curves. File sizes were between 150 and 300 Kbytes. Electronic transmission of the data took about one minute for gated SPECT studies and less than 2 minutes for other dynamic studies, considering connection at 33,6 KB/s. Data format was preserved and image quality suffered no degradation along the process. Conclusion: The proposed method is suitable to prepare and electronically deliver complete, high-quality nuclear medicine reports on a daily practical basis. Although image processing is not allowed, it can be of benefit for referring physicians, consultants and students/tutors in distance-learning courses

No abstract available

[en] Aim: To investigate the relationship between transient ventricular dysfunction detected by gated SPECT with the location, extension and severity of ischemic areas in patients with reversible perfusion defects. Material and Methods: We retrospectively studied 83 patients (61±11 yrs., 61 men, 27 with previous MI) submitted for coronary artery disease (CAD) evaluation with 99mTc-MIBI gated SPECT using a 2-day protocol whose perfusion imaging pattern had been reported positive for myocardial ischemia. Stress test was exercise in 54 cases, dipyridamole in 28 and dobutamine in 1. Previous work from our group demonstrated up to 12% change in LVEF from rest to post-stress in a population with low likelihood of CAD and a normal perfusion pattern. Thus, according to % variation of left ventricular ejection fraction (LVEF) from rest to post-stress we further divided the population into 2 subgroups, (A) with less than 12% change in LVEF (n=56) and (B) with more than 12% negative variation (n=27). For evaluation of perfusion, a simplified 7-segment division of the myocardium was used and a combined ischemic score was obtained by multiplying the number of segments with reversible defects by the 1-4 assigned severity score. Results: There was no significant difference between the two groups regarding age, gender, stress result (clinical or ECG), number of fixed perfusion defects or rest LVEF. Dipyridamole test was more frequent among patients of group B. Post-stress LVEF was 49±14% for group A and 41±15% for group B, p=0.0125. Combined ischemic score was 6.82±6.5 vs. 11.96±12 respectively, p=0.014. In patients of group A, defects corresponding to the right coronary territory were more frequent, while the left descending artery territory was more commonly affected in group B patients, however this was not statistically significant. Left circumflex territory was equally affected in both groups. Conclusion: Transient ventricular dysfunction after a stress test can be interpreted as true myocardial stunning and is related to the extent and severity of induced ischemia as determined by myocardial perfusion studies. It can be found either as a consequence of exercise or pharmacologic stimulus, and it might represent a parameter of additional clinical value for the management of patients with CAD

[en] Aim: To compare left ventricular ejection fraction (LVEF), end-diastolic volumes (EDV) and end-systolic volumes (ESV) measured by quantitative gated SPECT (QGSPECT) in studies acquired with and without magnification factor (zoom). Material and Methods: We studied 30 consecutive patients (17 men, ages 61±14 years) referred for myocardial perfusion evaluation with a 2-day protocol. Studies were performed after injection of 925 MBq (25 mCi) of 99mTc-MIBI in the resting state. Gated SPECT was first acquired using a x2 zoom factor and immediately repeated with x1 zoom (no magnification), using a 64x64 matrix and 8 frames/cardiac cycle. Patients with arrhythmia were not included in the investigation. According to the median EDV calculated with the x2 zoom acquisition, the population was further divided in two sub-groups regarding the size of the LV cavity. Average LVEF, EDV, ESV and difference between values (delta) were then calculated for the total population and for each sub-group (a and b). Results: For the total population, results are expressed.Pearson correlation showed r=0.954 between LVEF with and without zoom (p<0.0001), but linear regression analysis did not fit a specific model (p=0.18). Median EDV with zoom was 92.5 ml, allowing to separate 15 cases with EDV above (a) and 15 below that value (b). Results for both sub-groups are presented. Conclusion: Calculated LVEF is higher with no zoom, at the expense of decreasing both EDV and ESV. Although differences were very significant for all parameters, ESV changes were specially relevant with no zoom, particularly in patients with smaller hearts. Although good correlation was found between LVEF with and without zoom, no specific correction factor was found to convert one value into the other. Magnification factor should be kept constant in gated SPECT if calculated LVEF values QGSPECT are expected to be reliable, and validation of the method using different zoom factors should be considered

[en] Aim: It is usually possible to differentiate between between Paget's disease (PD) and metastatic involvement in bone scintigraphy. However, some diagnostic difficulty can arise, particularly when a PD pattern is incidentally found in a patient with a known primary tumor referred for a bone scan. The aim of the study was to evaluate, the positive predictive value (PPV) of bone scanning for the incidental diagnosis of PD in patients with known malignant diseases. Material and Methods: We retrospectively evaluated 3,149 bone scans from patients referred for oncologic staging between October 1995 and January 2002. In all cases a whole-body acquisition had been performed with a double-head gamma camera equipped with LEUHR collimators, using a dose of 740-1110 MBq of ^99mTc-MDP. A scintigraphic pattern of PD was found and reported in 40 patients (73.7 ± 11 years, 30 male) with prostate (n=20), breast (n=7), renal (n=5), and colon (n=2) carcinomas, melanoma (n=2), lung cancer (n=1), myeloma (n=1), pancreatic cancer (n=1), and bladder carcinoma (n=1). All studies were reported as negative for the diagnosis of bone metastases. Final results were confirmed by correlative imaging/follow-up (n=31) or bone biopsy (n=9). Results: Thirty-two out of 40 cases were considered as true-positive results for PD (PPV=80%), being 8 false-positive for such diagnosis in patients with confirmed bone metastases from breast (n=2), prostate (n=2), renal (n=2), lung (n=1), and bladder cancer (n=1). Three false positive cases were found among patients with scintigraphic diagnosis of monostotic PD (n=30) and 5 in the group of patients with reported polyostotic PD (n=10). Thus, PPVs were significantly different in both groups (90% vs. 50%, p=0.0145). No case of sarcomatous degeneration of pagetic bone was confirmed. Conclusion: PD and bone metastases share common biological properties characterized by focal increase in osteoclast formation and bone resorption mediated by interleukin (IL-6) and the RANK ligand. These facts could explain the potential of PD for mimicking the scintigraphic appearance of metastatic bone disease. However, specially when a multifocal PD pattern is recognized in a bone scan of a patient with a known malignancy, our results show that there is a high probability of missing true metastatic lesions

No abstract available

[en] Motivations, applications and design of the Fast Tracker upgrade for the ATLAS trigger are reported. The system would increase flexibility and power of the ATLAS high-level triggers by providing full inner detector tracking to all trigger algorithms within a short latency.