Feasibility of a prototype carbon nanotube enabled stationary digital chest tomosynthesis system for identification of pulmonary nodules by pulmonologists

Abstract

Background: Screen detected and incidental pulmonary nodules are increasingly common. Current guidelines recommend tissue sampling of solid nodules >8 mm. Bronchoscopic biopsy poses the lowest risk but is paired with the lowest diagnostic yield when compared to CT-guided biopsy or surgery. A need exists for a safe, mobile, low radiation dose, intra-procedural method to localize biopsy instruments within target nodules. This retrospective cross sectional reader feasibility study evaluates the ability of clinicians to identify pulmonary nodules using a prototype carbon nanotube radiation enabled stationary digital chest tomosynthesis system.Methods: Patients with pulmonary nodules on prior CT imaging were recruited and consented for imaging with stationary digital chest tomosynthesis. Five pulmonologists of varying training levels participated as readers. Following review of patient CT and a thoracic radiologist's interpretation of nodule size and location the readers were tasked with interpreting the corresponding tomosynthesis scan to identify the same nodule found on CT.Results: Fifty-five patients were scanned with stationary digital chest tomosynthesis. The median nodule size was 6 mm (IQR =4-13 mm). Twenty nodules (37%) were greater than 8 mm. The radiation entrance dose for s-DCT was 0.6 mGy. A significant difference in identification of nodules using s-DCT was seen for nodules <8 vs. ≥8 mm in size (57.7% vs. 90.9%, CI: −0.375, −0.024; P<0.001). Inter-reader agreement was fair, and better for nodules ≥8 mm [0.278 (SE =0.043)]. Conclusions:With system and carbon nanotube array optimization, we hypothesize the detection rate for nodules will improve. Additional study is needed to evaluate its use in target and tool co-localization and target biopsy.

X-ray source array optimization for mobile chest tomosynthesis

“…The detector is a 40x30cm panel with 194um pixel size. The sDCT system has been recently upgraded for increased angular coverage beyond the original system developed in our lab and demonstrated in human subjects 8,9 . The linear source array contains 63 individually addressable x-ray emitting focal spots enabled by carbon nanotube field emission cathode technology.…”

Stationary prospective cardiac gated computed tomography—dynamic study in phantoms and in vivo

“…The principles of x-ray generation in CNT based x-ray is the same as conventional x-ray; there is an electron source and applied voltage at the anode to accelerate the electrons to the target. The difference lies in the electron generation, which allows TTL logic-level (0-5 V) x-ray source control and close packing of x-ray sources into multi-beam x-ray tubes (Mol et al 2015, Gunnell et al 2019, Burks et al 2022. The logic-level control directly translates into the potential for physiologic gated acquisition (Puett et al 2018).…”