Objective:To analyze the effects of two decomposition algorithms of dual-energy cone beam CT (DECBCT) (direct decomposition and iterative decomposition) on the image quality and material decomposition accuracy of different sizes of phantoms.Methods:Different sizes of imaging parts of patients were simulated using the combination of CatPhan604 phantoms and customized annuluses. CBCT with high energy of 140 kVp and low energy of 100 kVp were acquired using the Varian Edge CBCT system. Then the material decomposition of DECBCT images was performed using the two algorithms. The electron density (ED) and contrast-to-noise ratio (CNR) of each material in the CTP682 module were calculated. They were used to assess the decomposition accuracy and image quality of the two algorithms.Results:Based on the values in the Catphan604 manual, both algorithms have high ED accuracy. Only the ED accuracy of four materials of the smallest sized phantom showed statistical difference ( z = -4.21, 4.30, 2.87, 5.45, P < 0.05), but the average relative error was less than 1%. The CNR of the iterative decomposition algorithm was significantly higher than that of the direct decomposition, increasing by 51.8%-703.47%. The increase in the phantom size significantly reduced the accuracy of ED, and the increased amplitude of the relative error was up to a maximum of 2.52%. The large phantom size also reduced the image quality of iterative decomposition, and the decreased amplitude of CNR was up to a maximum of 39.71. Conclusions:Compared with the direct decomposition, the iterative decomposition algorithm can significantly reduce the image noise and improve the contrast without losing the accuracy of electron density in the DECBCT construction of different sizes of phantoms.

Objective To investigate the articles on liver diseases published by authors from China (excluding Hong Kong, Macao, and Taiwan regions) in Gastroenterology & Hepatology journals indexed in Science Citation Index Expanded (SCIE) in 2016-2020, to analyze the bibliographic and citation data of these articles, and to understand the contribution and impact of Chinese scholars in the field of liver disease research in recent years. Methods The data for bibliometric analysis came from the SCIE database and Journal Citation Reports (JCR). The SCIE database was searched for the journal articles published in JCR Gastroenterology & Hepatology journals in 2016-2020, with a title or abstract containing "Liver", "Hepatocellular", "Hepatitis", "Cirrhosis", or "Hepatic" and a publication type of Article. Clinical guidelines were excluded, and the records with the corresponding author's affiliation containing institutions in China (excluding Hong Kong, Macao, and Taiwan regions) were screened out. R package bibliometrix was used to calculate the frequency of citations of included articles by liver disease studies published by Chinese and global authors in the Gastroenterology & Hepatology journals in 2016-2020, and R package DescTools was used to perform the Cochran-Armitage trend test to observe the change in composition ratio. Results In the Q1 Gastroenterology & Hepatology journals in 2016-2020, liver disease studies published by Chinese authors accounted for 9.5%. In recent years, the proportion of liver disease studies published by Chinese authors in Q1 Gastroenterology & Hepatology journals continues to increase from 6.0% to 12.2% ( P < 0.001). Among the liver disease studies published by Chinese authors in Q1 Gastroenterology & Hepatology journals, 79.7% were funded by National Natural Science Foundation of China, and there was no significant change in the proportion of studies funded by National Natural Science Foundation of China and published by Chinese authors in each partition of Gastroenterology & Hepatology journals in 2016-2020. The frequency of citations of included articles by liver disease studies published by Chinese and global authors in the Gastroenterology & Hepatology journals showed that liver disease studies published by Chinese authors had a high impact in both domestic and international academic communities. Conclusion In recent years, there has been a constant increase in the number of liver disease studies published by Chinese authors in high-impact Gastroenterology & Hepatology journals indexed in SCIE, and most of these studies have been funded by National Natural Science Foundation of China. The liver disease studies published by Chinese authors in Gastroenterology & Hepatology journals have been widely recognized by domestic and international academic communities.

OBJECTIVETo investigate the clinicopathological features and prognosis of colorectal synchronous multiple primary cancer(SMPC).

METHODSFrom January 2008 to June 2011, 51 patients diagnosed with colorectal SMPC underwent surgery at Department of General Surgery of Peking University First Hospital. Their clinicopathological features, diagnosis, treatment and prognosis were summarized and analyzed. SMPC was diagnosed according to the following criteria: each tumor must have a definite pathologic picture of malignancy; metastasis or recurrence from another colorectal cancer was excluded; tumors must be distinctly separated by at least 5 cm of all intact bowel wall from each other; SMPC has abnormal cells between tumor and normal mucosa and abnormal gland of transitional zone; each cancer is infiltrating carcinoma except the carcinoma in situ; all the cancers are detected at the same time or within 6 months. Multiple primary colorectal cancer originated from familial colonic polyposis or ulcerative colitis was excluded.

RESULTSThese 51 colorectal SMPC patients accounted for 3.5% of 1 452 colorectal cancer patients in the same period at our hospital, with 32 males and 19 females, and mean age of (63±13)(29 to 82) years. Of 51 cases, 46(90.2%) had 2 original carcinoma, 3(5.9%) had 3 original carcinoma and 2(3.9%) had 4 carcinoma; 23(45.1%) complicated with colon polyps, 4(7.8%) complicated with malignancy outside the colorectum. In TNM staging, 7(13.7%), 15(29.4%), 24(47.1%) and 5(9.8%) patients were stage I(, II(, III( and IIII( respectively. Among 51 patients undergoing surgery by different procedures, 16 were subtotal colon resection, 8 were extended right colon resection, 5 were extended left hemicolon resection, 8 were right hemicolon resection plus Dixon procedure, 10 were Dixon, and 4 were right hemicolon resection plus sigmoid colon resection. Adjuvant chemotherapy and support treatment were given according to the condition after operation. A total of 105 tumors were found, including 25(23.8%) tumors in sigmoid colon, 24(22.9%) in rectum, 22(21.0%) in ascending colon and 4 in organs outside the colorectum. Tubular adenocarcinoma (86/105, 81.9%) was the main pathological type in these colorectal SMPC patients. During the follow-up of median 43.5 months, 10 cases presented local recurrence and 6 cases had liver metastasis. Multivariable analysis showed that ≤65 years old (OR=22.757, 95%CI: 1.562-331.543, P=0.002),undifferentiated carcinoma or mucous adenocarcinoma (OR=27.174, 95%CI: 2.834-260.512, P=0.004), stage III(-IIII( (OR=29.626, 95%CI: 3.216-272.884, P=0.003) were independent risk factors of postoperative 5-year recurrence and metastasis, but the number of SMPC lesions and the surgical method were not associated with postoperative 5-year recurrence and metastasis (P=0.564, P=0.513). The 3-year and 5-year survival rates of colorectal SMPC patients were 76.5% and 64.7%.

CONCLUSIONTwo-original carcinoma is the most common in colorectal SMPC patients, which mainly distributes in sigmoid colon and rectum. Postoperative monitoring should be strengthened for those patients with younger age, poor pathological types and advanced staging to prevent recurrence and metastasis.