Stationary chest tomosynthesis using a carbon nanotube x-ray source array: a feasibility study

Abstract

Chest tomosynthesis is a low-dose, quasi-3D imaging modality that has been demonstrated to improve the detection sensitivity for small lung nodules, compared to 2D chest radiography. The purpose of this study is to investigate the feasibility and system requirements of stationary chest tomosynthesis (s-DCT) using a spatially distributed carbon nanotube (CNT) x-ray source array, where the projection images are collected by electronically activating individual x-ray focal spots in the source array without mechanical motion of the x-ray source, detector, or the patient. A bench-top system was constructed using an existing CNT field emission source array and a flat panel detector. The tube output, beam quality, focal spot size, system in-plane and in-depth resolution were characterized. Tomosynthesis slices of an anthropomorphic chest phantom were reconstructed for image quality assessment. All 75 CNT sources in the source array were shown to operate reliably at 80 kVp and 5 mA tube current. Source-to-source consistency in the tube current and focal spot size was observed. The incident air kerma reading per mAs was measured as 74.47 uGy mAs(-1) at 100 cm. The first half value layer of the beam was 3 mm aluminum. An average focal spot size of 2.5 × 0.5 mm was measured. The system MTF was measured to be 1.7 cycles mm(-1) along the scanning direction, and 3.4 cycles mm(-1) perpendicular to the scanning direction. As the angular coverage of 11.6°-34°, the full width at half maximum of the artifact spread function improved greatly from 9.5 to 5.2 mm. The reconstructed tomosynthesis slices clearly show airways and pulmonary vascular structures in the anthropomorphic lung phantom. The results show the CNT source array is capable of generating sufficient dose for chest tomosynthesis imaging. The results obtained so far suggest an s-DCT using a distributed CNT x-ray source array is feasible.

Second generation stationary digital breast tomosynthesis system with faster scan time and wider angular span

“…Geometric relationships between each source and its relative position to the detector were determined by imaging a calibration phantom that contains metal balls with known geometry. Projection images of the geometry phantom were taken at different heights and processed to determine their points of intersection using a statistical model based optimization method to determine the coordinates of each source relative to the center of the detector in 3D space …”

Stationary intraoral digital tomosynthesis using a carbon nanotube X-ray source array

“…42 The average focal spot size was measured as 2.5 3 0.5 mm (full width at half maximum) with the elongated direction along the source array. 36 The tube was operated at 5-mA tube current comparable to conventional intraoral X-ray sources. 10,11,39 A subset of the 75 sources was used for this study.…”

“…Multiple individually controllable X-ray sources are spatially distributed in a single X-ray tube to eliminate the need to position the X-ray source at different locations during image acquisition. This technology enables stationary tomography, which has been demonstrated in digital breast tomosynthesis, 32-34 digital chest tomosynthesis, 35,36 tomosynthesis-guided radiation therapy 37 and stationary CT for homeland security. 38 The purpose of this study was to investigate the feasibility of using a CNT X-ray source array for stationary intraoral tomosynthesis (s-IOT).…”

First-in-Human Study of Acoustic Angiography in the Breast and Peripheral Vasculature

“…Based on mammographic results, the lesion is assigned a score from 1 to 6 according to the Breast Imaging Reporting and Data System (BI-RADS) (Radiology 2013). For individuals with a suspicious mammogram (BI-RADS category 3–5), follow-up imaging with other approaches, including diagnostic mammography, breast tomosynthesis (Rafferty, et al 2013, Shan, et al 2015, Tucker, et al 2014), magnetic resonance imaging (Elsamaloty, et al 2009, Mountford, et al 2009), and ultrasound (Moon, et al 2002), may be utilized to clarify the nature of the lesion. Lesions ultimately categorized as BI-RADS 4–5 have a high likelihood of malignancy and are directed toward biopsy or surgical excision.…”