The invention provides a method for magnetic resonance imaging and spectroscopic analysis of a specimen which includes positioning the specimen within a main magnetic field and introducing an antenna having a loopless antenna portion in close proximity to the specimen. Radio frequency pulses are provided to the region of interest to excite magnetic resonance signals, gradient magnetic pulses are applied to the region of interest with the antenna receiving magnetic resonance signals and emitting responsive output signals. A processor processes the responsive output signals to provide image information for display in a desired manner. The method in a preferred form involves employing a flexible antenna. The method in another preferred form involves employing an impedance matching circuit electrically interposed between the loopless antenna and the processor to enhance radio frequency power transfer and magnetic resonance signal-to-noise ratio from the loopless antenna to the processor. The method may be used on a wide variety of specimens and in a preferred use is introduced into small blood vessels of a patient to facilitate determination of atherosclerotic plaque. Medical intervention procedures, such as plaque removal, may be employed generally simultaneously with the imaging of the present invention. Corresponding apparatus and magnetic resonance antenna assembly are provided.