CT reconstruction from simultaneous projections: a step towards capturing CT in One Go

Abstract

This paper focuses on minimizing the time requirement for CT capture through innovative simultaneous x-ray capture method. The state-of-the-art CT imaging methodology captures a sequence of projections during which the internal organ movements may lead to poor reconstruction due to motion artefacts. Traditional CT scanners' minimize such effect by taking more projections than necessary. In this work we focus on an innovative CT capture method that captures projections simultaneously, promising super fast scans along with possible radiation dose reductions. While the simultaneous CT capture model has already been proposed in our earlier work "Multi-axial CT Reconstruction from Few View Projections" (in SPIE Optical Engineering+ Applications, pp. 85000A-85000A. International Society for Optics and Photonics, 2012) and "A New Imaging Method for Real-time 3D X-ray Reconstruction" (in SPIE Medical Imaging, pp. 86685G-86685G. International Society for Optics and Photonics, 2013), in this work we enhance the model through better initialization along with prior smoothing before successive iterations of the iterative algorithms. We also elaborate the model considering different X-ray source/detector configurations. Results show that it is possible reconstruct a cross-section slice by considering only four angular projections. With eight projections, the reconstruction is further improved. The main promising matter about this method is that, all these projections (i.e. four or eight) can in principle be captured simultaneously, implying CT capture in one go just like a chest X-ray. IntroductionComputed Tomography (CT) is a medical imaging technique, employing tomography created by computer processing [1], whereas tomography is the process of imaging a cross-section, it comes from the Greek word tomos, which means a section or a slice or a cut [2]. The central idea of computed tomography is to produce 2-D and 3-D cross-sectional images of an object from flat X-ray images. CT has become one of the most important modalities in medical imaging; but unfortunately, the radiation exposure associated with CT is considered as a critical spin-off. With respect to patients' care, the least possible radiation dose is demanded.Existing Computed Tomography (CT) systems are vulnerable to internal organ movements. This drawback is compensated by extra exposures and digital processing. CT being a radiation dose intensive modality, it is imperative to limit the patient's exposure to X-ray radiation, if only by removing the necessity to take extra exposures.In order to minimize the number of projections, the proposed modality is based on simultaneous X-ray capture through a pinhole array akin to optical light field imaging. A fine array of pinholes is positioned in front of the detector allowing the determination of the direction of incoming X-rays along with their intensities. The simultaneous CT capture model has already been proposed in our earlier work [3,4]. In this work, we elaborate the model considering different X-ray so...

Algorithms in Tomography and Related Inverse Problems—A Review

“…This innovative design, featuring two X-ray tubes and two detectors, holds the potential to surmount the limitations of traditional multi-detector row computed tomography. In the pursuit of innovation, Saha, Tahtali et al [15] center on an innovative computed tomography acquisition method. This method enables simultaneous projection captures, potentially offering exceptionally rapid scans and reductions in radiation doses.…”