ABSTRACT
Multi-modality imaging is beneficial for both preclinical and clinical applications as it enables complementary information from each modality to be obtained in a single procedure. In this paper, we report the design, fabrication, and testing of a novel tri-modal in vivo imaging system to exploit molecular/functional information from fluorescence (FL) and photoacoustic (PA) imaging as well as anatomical information from ultrasound (US) imaging. The same ultrasound transducer was used for both US and PA imaging, bringing the pulsed laser light into a compact probe by fiberoptic bundles. The FL subsystem is independent of the acoustic components but the front end that delivers and collects the light is physically integrated into the same probe. The tri-modal imaging system was implemented to provide each modality image in real time as well as co-registration of the images. The performance of the system was evaluated through phantom and in vivo animal experiments. The results demonstrate that combining the modalities does not significantly compromise the performance of each of the separate US, PA, and FL imaging techniques, while enabling multi-modality registration. The potential applications of this novel approach to multi-modality imaging range from preclinical research to clinical diagnosis, especially in detection/localization and surgical guidance of accessible solid tumors.
Subject(s)
Multimodal Imaging/instrumentation , Optical Imaging/instrumentation , Photoacoustic Techniques/instrumentation , Ultrasonography/instrumentation , Animals , Breast Neoplasms/diagnostic imaging , Breast Neoplasms/pathology , Equipment Design , Fiber Optic Technology/instrumentation , Image Processing, Computer-Assisted , Lasers , Mice , Multimodal Imaging/methods , Neoplasm Transplantation , Optical Imaging/methods , Phantoms, Imaging , Photoacoustic Techniques/methods , Ultrasonography/methodsABSTRACT
BACKGROUND: Methamphetamine, a derivative of amphetamine, has been well known to cause mental problems in humans; however, its physical effects are little known. Despite relevant information on the effect of methamphetamine abuse on bone quality being available, data regarding the frequency of osteoporosis in methamphetamine abusers are limited. METHODS: We selected 46 hospitalized male methamphetamine abusers and 188 reference male controls in whom any conditions affecting bone metabolism were ruled out. Bone mineral density (BMD) in the lumbar spine was measured by dual energy X-ray absorptiometry (DXA). We compared the BMD between methamphetamine abusers and controls and evaluated the frequency of osteoporosis in both groups. RESULTS: The mean BMD value was lower in methamphetamine abusers (mean+/-SD, 0.71+/-0.07 g/cm(2)) than in the controls (mean+/-SD, 0.98+/-0.14 g/cm(2)). The frequency of osteoporosis was 22% according to WHO diagnostic guidelines, and osteopenia at the lumbar spine was 76%. The correlation between the extent of methamphetamine abuse and BMD was very clear. CONCLUSION: There was considerable loss of bone mineral in a high percentage of methamphetamine abusers. Our study is the first clinical study to determine the frequency of osteoporosis in male methamphetamine abusers.
