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The rat myocardial infarction (MI) model is widely used to study left ventricular (LV) remodeling. In this study, acipimox-enhanced (18)F-Fluorodeoxyglucose (FDG) gated-positron emission tomography (PET) was assessed for characterizing and predicting early remodeling in the rat infarct model. Nineteen Wistar rats had surgical occlusion of the left anterior descending coronary artery and 7 were sham-operated. PET was scheduled 48 h and 2 weeks later for quantifying MI area and LV function. Segments with <50% of FDG uptake had histological evidence of MI (74 ± 9% decrease in parietal thickness, fibrosis development). At 48 h, MI area was large (>35% of LV) in 6 rats, moderate (15-35% of LV) in 8 rats, limited (<15% of LV) in 5 rats and absent in the 7 sham rats. LV remodeling, assessed through the 2 weeks increase in end-diastolic volume, increased between rats with limited, moderate and large MI (+72 ± 25, +109 ± 56, +190 ± 69 μl, respectively, P = 0.007). This 3-groups classification allowed predicting 44% of the 2 weeks increase in end-diastolic volume, and additional 34% were predicted by heart rate at 48 h. The acipimox-enhanced FDG gated-PET technique provides efficient characterization and prediction of early remodeling in the rat infarct model. [ABSTRACT FROM AUTHOR]

Of 46 consecutive patients who underwent percutaneous transluminal coronary angioplasty (PTCA) from April 1980 to August 1982 and who had a satisfactory angiographic result six months later, one died of cancer and 41 had a detailed evaluation with exercise single-photon emission computed tomography (SPECT, 40 patients) or repeat coronary angiography (one patient), 48–78 months after the procedure. During follow-up, two patients had recurrent angina due to progression of coronary artery disease requiring a second PTCA procedure of another coronary artery; one of them later had a limited myocardial infarction in an area supplied by the vessel initially dilated. At follow-up, only one patient had definite angina. All but one patient had a negative exercise test. Myocardial perfusion during exercise in the PTCA-related area, assessed by SPECT, was normal in 90% of the patients and showed a limited defect due to reversible ischaemia in the remaining four (10%). It is concluded that patients with a less than 50% stenosis six months after PTCA show sustained improvement in their functional status and myocardial perfusion, four to six years after the procedure suggesting continued patency of the coronary artery. [ABSTRACT FROM PUBLISHER]

Isotopic diagnostic procedures such as thallium scintigraphy and radionuclide angiography are of extremely limited value in the diagnosis of left ventricular hypertrophy, however, they are of great value in the functional evaluation of such patients. Current developments in radioisotopic techniques, using metabolically active markers, may allow more detailed and cumplete evaluation of left ventricular hypertrophy and the cardiomyopathies. [ABSTRACT FROM PUBLISHER]

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- Sixteen patients with severe intractable haemorrhagic cystitis following radiotherapy, two of them with bleeding tumours, were treated surgically by cutaneous ureterostomy with or without contralateral nephrectomy. They had undergone various forms of conservative treatment and were treated by surgery only when conservative therapy had failed. In these poor risk patients a cutaneous ureterostomy was employed as a lesser procedure than an ileal loop. Of the 16 who underwent urinary diversion 11 were completely free of haemorrhage and three continued to have slight intermittent haematuria. [ABSTRACT FROM AUTHOR]

Introduction CZT cameras, such as the DSPECT one (Spectrum Dynamics®), involve a principle of direct detection to convert γ photon into an electric signal. SPECT-recordings from the DSPECT camera were already simulated with the GATE platform [1] , but without considering certain physical properties of semiconductors, in particular the partial collection of charges between anode and cathode leading to a low energy tailing effect [2] . This study aimed to model this property by using the Hecht equation [3] putting in relation the amount of collected charge with the depth of interaction of the γ photon within the CZT crystal. Materials and methods The Hecht equation was used to model the response of the 9216 pixels of the DSPECT camera. A comparison was planned between the energy spectra provided by simulated and actually recorded data from a source of 99 m Tc setting in the air or in a diffusing environment (water cylinder of a 8.5 cm diameter). Results A good agreement was documented between the energy spectra from simulated and actually recorded data in the air as well as in the diffusing environment. An under-estimation was however documented for the low-energy photons obtained with the simulation, particularly in diffusing environment and in the lower part of the recording window of the 99 m Tc photopeak (relative decreases of −7.5% in the air and of −3.6% in the diffusing environment for the interactions simulated at 126 keV and compared to actual data). Conclusion The modelling of charge collection allows improving the Monte-Carlo simulation of SPECT-recording with energy spectra being close to those actually observed with CZT cameras. [ABSTRACT FROM AUTHOR]

Introduction New solid-state CZT cameras provide high quality images, with a better spatial resolution than conventional Anger cameras [1] , but their robustness and sensitivity to cardiac motions remains to be assessed. The aim of this study was to compare the motion-related artefactual variations in the wall uptake of a cardiac phantom between the CZT cameras Discovery NM-530c (GE) and DSPECT (Spectrum Dynamics) and the Anger camera Symbia T2 (Siemens), which was equipped with an astigmatic (IQSPECT) or parallel-hole (conventional SPECT) collimator. Materials and methods Translations of a cardiac insert, which walls were filled-in with a solution containing 99m Tc, were applied in 6 different directions (−X/+X, −Y/+Y et −Z/+Z) and with various amplitudes at half of each SPECT recording. Images were reconstructed with routine parameters [2] . The motion-related artefactual variations in myocardial uptake were assessed according to the difference in segmental uptake between each SPECT recorded with an insert translation and the corresponding normal SPECT-recording and by using a 17 segments division of the left ventricle [3] . Differences >10% were considered as significant. Results and conclusion For translations of only 5 mm, the variations in segmental uptake were not or only poorly significant whatever the camera type. For higher translation amplitudes, the CZT D530c camera exhibited the higher sensitivity to motion and the DSPECT, the lower one, whereas Anger cameras were at an intermediate level irrespective of the collimator type (parallel-hole or astigmatic). [ABSTRACT FROM AUTHOR]