The present invention provides an imaging probe for imaging mammalian tissues and structures using high resolution imaging, including ultrasound and optical coherence tomography. According to the invention, the deprotection of protected hydroxy group required in manufacturing a 15-keto-prostaglandin derivative is conducted under the presence of a phosphoric acid compound. A one-way valve forms a seal between the rolled end seam and an outer surface of the body wall. The diffusion suppressing film also suppresses diffusion of the lubricant from the second space to the first space. In embodiments, the brush has at least a portion that carries bristles that are curved and extend from the core in oriented manner. Still other embodiments of the present disclosure include a corona electrode for inducing ignition of the gas.