One-step Iterative Estimation of Effective Atomic Number and Electron Density for Dual Energy CT

Dual-energy computed tomography (DECT) is a promising technology that has shown a number of clinical advantages over conventional X-ray CT, such as improved material identification, artifact suppression, etc. For proton therapy treatment planning, besides material-selective images, maps of effective atomic number (Z) and relative electron density to that of water ($\rho_e$) can also be achieved and further employed to improve stopping power ratio accuracy and reduce range uncertainty. In this work, we propose a one-step iterative estimation method, which employs multi-domain gradient $L_0$-norm minimization, for Z and $\rho_e$ maps reconstruction. The algorithm was implemented on GPU to accelerate the predictive procedure and to support potential real-time adaptive treatment planning. The performance of the proposed method is demonstrated via both phantom and patient studies

Image-Domain Material Decomposition for Dual-energy CT using Unsupervised Learning with Data-fidelity Loss

Background: Dual-energy CT (DECT) and material decomposition play vital roles in quantitative medical imaging. However, the decomposition process may suffer from significant noise amplification, leading to severely degraded image signal-to-noise ratios (SNRs). While existing iterative algorithms perform noise suppression using different image priors, these heuristic image priors cannot accurately represent the features of the target image manifold. Although deep learning-based decomposition methods have been reported, these methods are in the supervised-learning framework requiring paired data for training, which is not readily available in clinical settings. Purpose: This work aims to develop an unsupervised-learning framework with data-measurement consistency for image-domain material decomposition in DECT

The stele tablet of a thousand Buddhist statues (千佛碑), Yunju Temple (雲居寺)

The stele tablet of a thousand Buddhist statues (千佛碑) at Yunju Temple (雲居寺). The tablet is full of small shrines on all sides, with more than a thousand carved Buddhist statues inset into the stone. The front of the tablet was engraved in 621 during the Sui Dynasty 隨 (581-618), whose words are now difficult to read. This form of inscription, which is rare in China, was unearthed at Dou Dian 窦店 Ancient City site in Fangshan District 房山 and moved to Yunju Temple 雲居寺 in the 1970s.The texture is turquoise, 2.66 meters high.Non UBCUnreviewedAuthor Affiliations: University of Arizona, Zhejiang University, Tsinghua UniversityGraduat

Rubbing of the Fangshan Canon-Mahāprajñāpāramitā-sūtra fascicle twenty-eight (833), Fanyuan Temple (法源寺)

Rubbing of the Fangshan Canon, Fanyuan Temple (法源寺). In the Guest Hall, we get the chance to look at the rubbing of the Fangshan Canon, which is the beginning part of Mahāprajñāpāramitā-sūtra fascicle twenty-eight (833). The length of the rubbing: 1.95m; the width of the rubbing 56cm, the length of each character is 2cm.Non UBCUnreviewedAuthor Affiliations: University of Arizona, Zhejiang University, Tsinghua UniversityGraduat

Inscription of the Clerk of the Ministry of Rites 禮部令史題名記, Fanyuan Temple (法源寺)

The stele with the inscription of the Clerk of the Ministry of Rites (禮部令史題名記) is exhibited in the Minzhong Hall (憫中閣) of Fayuan Temple (法源寺). It is 65cm high, 40cm long and 8cm in wide.Non UBCUnreviewedAuthor Affiliations: University of Arizona, Zhejiang University, Tsinghua UniversityGraduat

Buddha statue soul bottle (佛像魂瓶, 222-245), Fanyuan Temple (法源寺)

Buddha statue soul bottle in the Vairocana Hall (Pilu dian 毗盧殿) of Fayuan Temple (法源寺) is about 26cm high. The bottle is made of bluestone. According to the monks in Yunju Temple (雲居寺) it symbolized the integration of Buddhism and secular culture.Non UBCUnreviewedAuthor Affiliations: University of Arizona, Zhejiang University, Tsinghua UniversityGraduat

Tang Dynasty Pagoda(開元十二年佛塔), Yunju Temple (雲居寺)

Square pagoda at Yunju Temple (雲居寺). The north facing side of the pagoda has a doorway. Inside on the right and left wall are carvings of vajra-warriors (金鋼力士). The wall opposite the door way contains a carving of a buddha and two bodhisattvas surrounded by six male lay disciples and six female lay disciples.Non UBCUnreviewedAuthor Affiliations: University of Arizona, Zhejiang University, Tsinghua UniversityGraduat

Feng Bao merit tablet (馮保功德碑), Yunti an (雲梯庵)

The merit tablet is located beside the Yunti an (雲梯庵). It was made in 1576, during the Ming Dynasty 明 (1368-1644) on the Buddha's Birthday. The tablet was made for Feng Bao 馮保 (1543-1583), one of the most influential eunuchs from the Ming Dynasty, who sponsored the restoration of the temples.Non UBCUnreviewedAuthor Affiliations: University of Arizona, Zhejiang University, Tsinghua UniversityGraduat

Vajra Sutra Stele 金剛經碑, Shijing shan (石經山)

There are two steles near the entrance of Leiyin Cave (Leiyin dong 雷音洞) of Shijing shan (石經山). The right one was carved with the Vajra Sutra (金剛經), which is 149.02cm high, 19.5cm wide and 91.3cm long. The base is 31cm high and 60 wide. According to the inscriptions on both the stele and the base, the base was built during the reign of Empress Wu of Zhou (Alt. Qu Zetian 武則天, r.690-705) during the Tang Dynasty 唐 (618-907), whereas the stele was built during the Ming Dynasty 明 (1368-1644).Non UBCUnreviewedAuthor Affiliations: University of Arizona, Zhejiang University, Tsinghua UniversityGraduat

Stone Stele outside Leiyin cave (雷音洞), Shijing shan 石經山)

There are four steles on the right side of the Leiyin Cave (Leiyin dong 雷音洞) of Shijing shan (石經山). While three of them are Buddhist sutras, the one behind the other three records the accomplishment of the carving of the four sutras. Its name is (Sida bu jing chengjiu beiji si 四大部經成就碑記). The base is 13cm high, 60 cm wide, and 39 cm long. The stele is 114 cm high, 59 cm wide, and 10 cm long.Non UBCUnreviewedAuthor Affiliations: University of Arizona, Zhejiang University, Tsinghua UniversityGraduat