The invention provides a method for magnetic resonance imaging and spectroscopic analysis of the interior of a specimen which includes positioning the specimen within a main magnetic field, introducing an invasive probe having an elongated receiver coil into or adjacent to the specimen with the coil having at least one pair of elongated electrical conductors, preferably, generally parallel to each other disposed within a dielectric material and having a pair of ends electrically connected to each other. RF 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 receiver coil receiving magnetic resonance signals and emitting responsive output signals which may be processed by a computer to provide image information for display in a desired manner. The method in a preferred form involves employing a flexible receiver coil which has uniform sensitivity along the coil and may be operated even when the magnetic resonance signal is in an oblique position. Tuning capacitance may be distributed along the length of the coil and/or a Faraday screen provided to minimize dielectric losses between the coil and the surrounding material of the specimen. 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 is provided.