Spectral editing of tumor 13C MRS in situ

The editing pulse sequence DEPT (D.T. Pegg, D.M. Doddrell, and M.R. Bendall, J. Chem. Phys. 77, 2745 (1982)) was modified using a scheme of various composite pulses and a 16-step phase cycling to obtain proton-decoupled natural-abundance 13C edited subspectra of solid tumors. A solenoidal probe including a Faraday shield and an orthogonal saddle decoupling coil was built for this purpose.

[In vivo radiotelemetric study of strain on the rabbit mandible]

Using strain transducer to measure bone strain and stress in vitro on-line techniques are more popular. In this article, the radiotelemetric method is selected for measuring living tissue mechanic properties. The angle of rabbit mandible serves as tested site. The transducer is minutely foil type electrical resistance strain gage. The measuring instruments are KYOWA telemeter for strain measurement MRT-200 series. When the mandible is in rest position, the tested site shows no change of strain; when the mandible acts without eating any food, small change of strain appear; when the rabbit mastication two kinds of food, the tested site shows the regular change of tension strain and compressive strain, the former is about 150 microstrain and latter is about 30 microstrain. The rates of strain are different when the animal mastication the different foods. Comparing with the on-line technique method, the radiotelemetric method has significant advantages, and is the better test way for studying mechanic properties of living tissue.

Monitoring therapeutic response of human superficial tumors using phase-encoded spectroscopy

A one-dimensional phase-encoded spectroscopy sequence was implemented on a GE 1.5-T Signa imager and the feasibility of its application to monitor the 31P metabolites of superficial tumors was demonstrated. Serial 31P spectra of 1-cm slices with adequate signal-to-noise ratio and insignificant T2 weighting can be obtained in 28 min. The degree of "bleeding" effect was reduced with increased phase-encoding steps.

Human in vivo 31P spectroscopy of skin: potentially a powerful tool for noninvasive study of metabolism in a cutaneous tissue

The first application of human in vivo phosphorus (31P) magnetic resonance spectroscopy to analysis of skin metabolism is presented. Our results confirm that phosphocreatine is a major energy phosphometabolite in human skin. Human in vivo 31P spectroscopy utilizing a skin coil designed in our laboratory can have clinical applications in cutaneous surgery and clinical dermatology, and will facilitate understanding of the pathophysiology of skin disease. In vitro experiments with fresh human skin indicate that complete utilization of phosphocreatine is followed by utilization of adenosine triphosphate (ATP) molecules during ischemia. These experiments also suggest that the majority of phosphocreatine in human skin is localized in epidermal and papillary dermis.