# Synchrotron X-ray Radiation (SXR) in Medical Imaging: Current Status and Future Prospects
## 3 Synchrotron X-ray Radiation in Medical Imaging  
SXR imaging provides several advantages over conventional X-ray radiation that can be utilized in medical imaging, e.g., (i) high intensity, (ii) tunability, (iii) very good natural collimation, etc. [5; 9]. The wide range of applications of SXR in medical imaging has been investigated over the years. By the mid-1980s, researchers were able to investigate human tissues, tendons, cartilages and brain, by producing synchrotron-based mammography, CT and digital subtraction angiography [5; 9]. Furthermore, SXR showed to be a valuable tool for non-invasive imaging of brain cytoarchitecture at cellular resolution (i.e., imaging whole neurons), which studies neurons morphology and connectivity with a pixel size down to 0.82 \(\upmu\)m for high resolution, which is far superior to that produced by the most advanced CT, MRI and DSA [10]. The application of SXR in medical imaging is summarized in Table 1. Some of the notable applications are discussed in more detail in the following subsections. \begin{table}
\begin{tabular}{c c c c} \hline
**Reference** & **Type of Source and** & **Application** & **Further Information** \\ \hline \multirow{3}{*}{[PERSON] et al. [11]} & Synchrotron radiation phase & & Analysis of gallstone \\  & contrast X-ray & & ultrastructure. \\  & microtomography. & & X-ray energy used was 9 keV \\  & & & The horizontal and vertical spatial \\  & & & coherence lengths were roughly \\  & & & 7 mm and 21 mm, respectively. \\ [PERSON] et al. [12] & Synchrotron radiation phase & Study of human stomach and & The distance between the detector & and the sample was 50 cm. \\  & contrast imaging. & & The spatial resolution of the \\  & & & imaging detector was 10 mm. \\  & & & X-ray energy used was 6.78 keV. \\  & & & The dimension of objective zone \\  & & & plate: outermost zone width was 50 nm, diameter was 140 mm and \\  & & & thickness was 1.0 mm. \\ [PERSON] et al. [13] & Synchrotron nanoscopy & Study of scalp hair in breast & The diameter of the detector was \\  & imaging & cancer patients and healthy & 10-\(\upmu\)m diameter. \\  & imaging & & The first-order focal \\  & & & length was 40 mm. \\  & & & The field of view was 110 \(\upmu\)m. \\  & & & The resolution was 100 nm. \\  & & & Each pixel size was \\  & & & 40,963 \(\times\) 4096 pixels in 9 \(\upmu\)m size. \\  & & & X-ray energy was 30 keV. \\  & & Total number of projections were & 900, spanning 180\({}^{\circ}\) of rotation for \\  & & & each sample. \\  & & & each sample. \\  & & & The field of view was \\  & & & 3.6 mm \(\times\) 2.4 mm. \\  & & & Total scan time per sample was 2 \\  & & & h with exposure times ranging \\  & & & from 400 to 600 ms per frame. \\  & & Bone research: & X-ray energy used was 25 keV. \\ [PERSON] et al. [15] & Synchrotron radiation & (i) Microstructural features, & FOV was a 0.15 \(\times\) 0.15 mm\({}^{2}\) \\  & microtomography analysis & (ii) Crack propagation and & area for 50 nm. \\  & & fracture and (iii) & The resolution was 30 to 100 nm. \\ \hline \end{tabular}
\end{table} 
Table 1: Applications of synchrotron X-ray radiation in medical imaging. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Reference** & **Type of Source and** & **Application** & **Further Information** \\ \hline [PERSON] et al. [16] & Synchrotron radiation-based phase-contrast computed tomography & Visualization of the atrioventricular conduction axis in human whole heart specimens. & The system had the following specifications: Field of view, 24.7 mm (H) \\  & Synchrotron radiation-based atrioventricular conduction & 17.1 mm (V); Voxel size, 12.5 mm; Density resolution, 1 mg/cm\({}^{3}\), \\  & tomography & \