FIELD: medicine.SUBSTANCE: group of inventions includes means for narrow lumen maintaining in the body, a device for narrow lumen diagnosis in the body with a tubular anatomical structure in the body, a device for fallopian tubes diagnosis, a method of narrow lumen maintaining in the body (versions), a method for narrow lumen fallopian tubes maintaining relate to medicine and are intended for diagnostic imaging or therapeutic agents treatment for effective narrow lumen maintaining in the body. A device for narrow lumen maintaining in the body comprises a hydraulic pushing mechanism and a withdrawal assembly. Hydraulic pushing mechanism for pushing of a portion for imaging or therapeutic portion through the said narrow lumen in the body is configured to push the said portion for imaging or the said therapeutic portion relative to the said hydraulic pushing mechanism and through the narrow lumen of the body. The said hydraulic pushing mechanism includes an elongated tubular member. The narrow lumen in the body is located distally relative to the distal end of the elongated tubular member. During pushing by means of the said hydraulic pushing mechanism, the said imaging portion or the said therapeutic portion is driven distally from the said distal end of the said elongated tubular member, and hydraulically forced through the narrow lumen in the body. The withdrawal mechanism is designed to withdraw the said imaging portion or the said therapeutic portion from the said narrow lumen in the body. A method for narrow lumen maintaining in the body includes creation of a seal inside or outside of the said narrow lumen in the body, so that the presence of fluid creating hydraulic pressure in the said narrow lumen of the body caused pressure injection for diagnostic imaging of the said narrow lumen in the body via the imaging portion hydraulic pushing by the said fluid creating hydraulic pressure of the said portion to produce an image through the said narrow lumen in the bod
