This study described and validated a new solid-state singlephoton g-camera and compared it with a conventional-SPECT Anger camera. The compact new camera uses a unique method for localizing g-photon information with a bank of 9 solid-state detector columns with tungsten collimators that rotate independently. Methods: Several phantom studies were performed comparing the new technology with conventional-SPECT technology. These included measurements of line sources and single-and dual-radionuclide studies of a torso phantom. Simulations were also performed using a cardiothoracic phantom. Furthermore, 18 patients were scanned with both the new camera and a conventional-SPECT camera. Results: The new camera had a count sensitivity that was 10 times higher than that of the conventional camera and a compensated spatial resolution that was moderately better. Dual-radionuclide studies using a phantom show the further potential of the new camera for a 2-tracer simultaneous acquisition. Two-minute clinical studies with the new camera and 11-min studies with the conventional camera qualitatively showed good-to-excellent image quality and improved myocardial edge definition for the new camera. Conclusion: These initial performance characteristics of a new solid-state single-photon g-camera offer great promise for clinical dynamic SPECT protocols, with important implications for applications in nuclear cardiology and molecular imaging. Nucl ear medicine has evolved as a clinical and research discipline for the noninvasive assessment of physiologic and molecular function in normal and diseased tissues. Principally performed with nanomolar quantities of administered radiopharmaceuticals and an external scintillation camera, nuclear medicine imaging uses 2 types of modalities: singlephoton imaging (including planar imaging and SPECT) and PET, with the former comprising nearly three fourths of all clinical procedures. With SPECT, myocardial perfusion studies predominate; these studies were performed in approximately 7,000,000 patients in the United States in 2004 and provided images of relative myocardial perfusion at rest and under stress. By assessing the extent of ischemic and infarcted myocardium, SPECT provides noninvasive information that has become central in clinical decision making, determining the need for invasive cardiac catheterization and myocardial revascularization in many patients (1,2).SPECT is typically performed using an Anger scintillation camera, named after its inventor, Hal Anger (3). Most myocardial SPECT is performed with 2 scintillation cameras oriented at 90°and mounted on a gantry that rotates around the patient. Typically, each scintillation camera is equipped with parallel-hole high-resolution collimators. Since collimation is necessary to acquire the projection views, only 0.02% of the photons emitted from the heart are collected. As a result, acquisition times of 10-20 min are required for myocardial SPECT studies. Although new detector technologies using solid-state materials have been explored (...

Background-Low-energy laser irradiation (LELI) has been found to attenuate various biological processes in tissue culture and experimental animal models. The aim of the present study was to investigate the effect of LELI on the formation of scar tissue in experimentally induced chronic infarct in rats and dogs. Methods and Results-Myocardial infarction (MI) was induced in 50 dogs and 26 rats by ligation of the left anterior descending coronary artery. After induction of MI, the laser-irradiated (LI) group received laser irradiation (infrared laser, 803-nm wavelength) epicardially. Control MI-induced non-laser irradiated (NLI) dogs were sham-operated, and laser was not applied. All dogs were euthanized at 5 to 6 weeks after MI. Infarct size was determined by TTC staining and histology. The laser treatment (PϽ0.05) lowered mortality significantly, from 30% to 6.5%, after induction of MI. The infarct size in the LI dogs was reduced significantly (PϽ0.0001) (52%) compared with NLI dogs. Histological observation of the infarct revealed a typical scar tissue in NLI dogs and cellularity in most of the LI dogs. Only 14Ϯ3% of the mitochondria in the cardiomyocytes in the ischemic zone (4 hours after MI) of LI MI-induced rats were severely damaged, compared with 36Ϯ1% in NLI rats. Accordingly, ATP content in that zone was 7.6-fold (significantly) higher in LI than in NLI rats. Conclusions-Our observations indicate that epicardial LELI of rat and dog hearts after chronic MI caused a marked reduction in infarct size, probably due to a cardioprotective effect of the LELI. Key Words: ischemia Ⅲ myocardial infarction Ⅲ antioxidants Ⅲ lasers T he approach to acute myocardial infarction (MI) has moved in the past decade from simple monitoring of coronary events to aggressive interventions in the processes underlying coronary thrombosis. Cardiac repair after infarct is a complex process involving diverse inflammatory components, extracellular matrix remodeling, and responses of the cardiomyocytes to the ischemia. 1,2 The sequential events that take place in the myocardium after occlusion of the left anterior descending coronary artery (LAD) in experimental animals (including dogs) have been well documented. 1,2 After necrosis of the cardiomyocytes and a rather long inflammatory phase, the ischemic zone is subsequently replaced by fibrotic tissue.Many studies have been directed toward the use of drugs, growth factors, and various interventional technologies in reducing myocardial infarct size and improvement of heart function after MI in experimental animals and humans. For example, recombinant adenovirus-mediated transfer of genes encoding antioxidants to the myocardium has been demonstrated to attenuate after ischemic dysfunction in neonatal mice. 3 Novel approaches to enhancing angiogenesis in the ischemic myocardium by introducing growth factors (mainly of the vascular endothelial growth factor family) were adapted and found to have a beneficial effect on patients with severe angina. 4 Low-energy laser irradiation (LELI) has b...

The results of the present study indicate that delivery of low-energy laser irradiation to infarcted myocardium in rats and dogs has a profound effect on the infarct size after MI.

Summary Clinical or chemical (latent) diabetes was discovered in 7 of 8 patients with generalized granuloma annulare; all were women. The average age of onset of their disease was 50 years. Treatment with chlorpropamide and low carbohydrate diet seemed to alleviate the skin manifestations in 6 of 7 patients so treated.