Embodiments of methods and/or apparatus for a radiographic imaging can include a plurality of x-ray sources disposed in a curve and a detector configured to revolve relative thereto. In one embodiment, a CBCT imaging method and/or apparatus can include performing a first scan at a first speed using stationary angularly distributed x-ray sources to acquire first CBCT projection data that impinge a detector of a first field of view (FOV), identifying an area of interest within the first FOV, and performing a second scan at a second speed using the x-ray sources acquire second CBCT projection data that impinge a portion of the detector of a second smaller FOV including the area of interest within the first FOV using second emissions by the x-ray sources, where the second speed is greater than the first speed.

An X-ray diagnostic apparatus according to an embodiment includes an X-ray tube holding device, an X-ray detector, a rotator, an arm, and a tubular body. The X-ray tube holding device generates X-rays. The X-ray detector detects the X-rays. The rotator holds the X-ray tube holding device so as to be rotatable about a first rotation axis obtained by setting an irradiation direction of the X-rays as an axis. The arm holds the rotator and the X-ray detector and is rotatable about a second rotation axis different from the first rotation axis. The tubular body connects the X-ray tube holding device and a device away from the arm. The arm holds the rotator so as to be rotatable about the first rotation axis in a direction in which torsion of the tubular body is reduced.

An X-ray tube comprises a vacuum vessel; a cathode and an anode fixedly disposed inside the vacuum vessel; and a rotary mechanism that rotates the vacuum vessel. The cathode is disposed on the circumference with the rotary shaft of the rotary mechanism as its center and includes a plurality of cathode parts that can individually be turned ON/OFF. The anode includes parts opposite to the plurality of cathode parts, respectively.

There is provided an X-ray source for an X-ray diffraction apparatus. The source includes a target and a filament operable to generate an X-ray beam, a vacuum chamber, outer and inner housings and a rotation mechanism. The chamber encloses the target and the filament and has a window transparent to the beam. The outer housing is mountable to the apparatus and includes outer housing openings. The inner housing encloses the chamber and is mounted to the outer housing. The inner housing includes inner housing openings positioned to be aligned with the window and the outer housing openings. The rotation mechanism is in engagement with the outer housing and the inner housing and is operable to provide a rotation between the inner outer housings between a line focus configuration, wherein the filament is parallel to the window, and a point focus configuration, wherein the filament is perpendicular to the window.