Correlations between in vivo 31P NMR spectroscopy measurements, tumor size, hypoxic fraction and cell survival after radiotherapy.

Phosphorus metabolite levels were measured non-invasively using 31P magnetic resonance spectroscopy (MRS) in SCCVII/SF tumors, subcutaneously transplanted into the legs of unanesthetized C3Hf/Sed mice. Shortly after MRS measurements, tumors were irradiated with a single dose of 20 Gy, and cell survival and radiobiologic hypoxic fraction were determined with an in vitro cloning assay. Significant correlations were found between tumor size and surviving fraction, hypoxic fraction, pH, and phosphorus metabolite ratios.

Acute myocardial ischemia and reperfusion: MR imaging with albumin-Gd-DTPA.

The utility of a macromolecular, intravascular contrast agent, albumin-gadolinium diethylenetriaminepentaacetic acid (DTPA), for the differentiation of acutely ischemic and reperfused myocardium on magnetic resonance (MR) images was investigated. Regional, reversible myocardial ischemia was produced in rats and confirmed. After reperfusion, flow to the compromised myocardial segment returned to baseline.

Integrated MR imaging and spectroscopy with chemical shift imaging of P-31 at 1.5 T: initial clinical experience.

A section-selective three-dimensional phosphorus-31 chemical shift imaging (CSI) experiment was evaluated as the spatial localization method for spectroscopy in an integrated clinical magnetic resonance (MR) imaging and spectroscopy examination. The results of a CSI experiment can be displayed as either spectra related to specific voxels or "metabolite maps," in which the relative concentration of a given metabolite is displayed as an overlay of the MR image. This method was applied to the study of a soft-tissue mass and to a meningioma.

Human in vivo phosphate metabolite imaging with 31P NMR.

Phosphorus (31P) spectroscopic images showing the distribution of high-energy phosphate metabolites in the human brain have been obtained at 1.5 T in scan times of 8.5 to 34 min at 27 and 64 cm3 spatial resolution using pulsed phase-encoding gradient magnetic fields and three-dimensional Fourier transform (3DFT) techniques.

Magnetic resonance imaging of myocardial infarction using albumin-(Gd-DTPA), a macromolecular blood-volume contrast agent in a rat model.

Magnetic resonance (MR) contrast enhancement of acute myocardial infarction was studied in rats using albumin-(Gd-DTPA), a paramagnetic macromolecule with prolonged intravascular retention after intravenous injection. Histologic examination and distribution measurements of radiolabeled microspheres confirmed induction of regional myocardial infarction after ligation of the left coronary artery. ECG-gated spin-echo images at 2.