A non-invasive method for locating a target blood vessel and imaging particles flowing therethrough, the method comprising: illuminating from an imaging probe at least a first sub-region of a region including at least a portion of the target blood vessel using a background light source providing a background light component having a substantially high susceptibility to absorption by particles in said portion of the target blood vessel; detecting backscattered background light from said illuminated sub-region; reproducing at least one image from said backscattered background light; identifying higher-absorbing regions within said reproduced image; non-invasively moving the illumination to a second or further sub-region when no higher-absorbing region corresponding to said portion of the target blood vessel is positioned along a focal line defined by a line-imaging illumination source of the imaging probe; iteratively applying said steps of illuminating, detecting, reproducing, identifying, and moving, until said higher-absorbing region is positioned along the focal line; and imaging confocally along the focal line using light from the line-imaging illumination source; characterized in that: the line-imaging illumination source comprises a broadband illumination source, and the light from the broadband illumination source comprises broadband light spectrally dispersed across the focal line such that light used to image from the focal line spectrally encodes position along the focal line; and the illuminating by both the line-imaging illumination source and the background imaging source is from an objective lens and through an optically transparent surface of a cap of the imaging probe, while the transparent surface of the cap is pressed against a surface of the region to define a depth of imaging through the objective lens therein; wherein said optically transparent surface is attached to said cap and wherein said illuminating is through said optically transparent surface. illuminating from an imaging probe at least a first sub-region of a region including at least a portion of the target blood vessel using a background light source providing a background light component having a substantially high susceptibility to absorption by particles in said portion of the target blood vessel; detecting backscattered background light from said illuminated sub-region; reproducing at least one image from said backscattered background light; identifying higher-absorbing regions within said reproduced image; non-invasively moving the illumination to a second or further sub-region when no higher-absorbing region corresponding to said portion of the target blood vessel is positioned along a focal line defined by a line-imaging illumination source of the imaging probe; iteratively applying said steps of illuminating, detecting, reproducing, identifying, and moving, until said higher-absorbing region is positioned along the focal line; and imaging confocally along the focal line using light from the line-imaging illumination source; the line-imaging illumination source comprises a broadband illumination source, and the light from the broadband illumination source comprises broadband light spectrally dispersed across the focal line such that light used to image from the focal line spectrally encodes position along the focal line; and the illuminating by both the line-imaging illumination source and the background imaging source is from an objective lens and through an optically transparent surface of a cap of the imaging probe, while the transparent surface of the cap is pressed against a surface of the region to define a depth of imaging through the objective lens therein;