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Objective:To explore the application effect of magnetic resonance imaging (MRI) sequence experiment based on virtual simulation software in undergraduate teaching of medical imaging technology.Methods:Fifty-six undergraduate students from the Batch 2015 and Batch 2016 medical imaging technology of West China Clinical Medical College of Sichuan University were recruited in this study. They were divided into 2 groups: experimental group (Batch 2016) and control group (Batch 2015). The experimental group adopted the teaching method based on virtual simulation experiment, and the control group used the teaching method based on traditional small-sized magnetic resonance. The after-class test scores and final exam scores of the two groups of students were compared, and the questionnaire survey on teaching effectiveness was conducted for students in the experimental group SPSS 21.0 was used for ttest and Mann-Whitney Utest. Results:The scores of theoretical knowledge and the final grades in the experimental group were significantly higher than those of the control group [(84.55 ± 6.57) points vs. (79.37 ± 6.13) points; (90.03 ± 4.72) points vs. (80.06 ± 7.29) points, all P< 0.05). The effective recovery rate of the questionnaires was 100%, and the questionnaire survey showed that the experimental group was significantly superior to the control group in such four aspects as increasing subject interest, expanding relevant knowledge, solving clinical work, and promoting teamwork ( P< 0.05). Conclusion:In MRI sequence teaching, the teaching method based on virtual simulation software can increase the students' interests in learning, strengthen their understanding of MRI principles, then effectively improve the teaching effect of medical imaging undergraduate education.
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Objective To explore the value of methylation of SDC2 and SFRP2 genes promoter in fecal DNA for colorectal cancer ( CRC) screening. Methods All stool samples were enrolled from Changhai Hospital of Naval Medical University, the Tenth People' s Hospital of Tongji University and the Seventh Medical Center of Chinese People's Liberation Army General Hospital. A total of 500 stool samples collected from March 2018 to December 2018 were allocated to CRC group ( 132 CRCs ) , adenoma group ( 38 advanced adenomas), healthy group (152 healthy individuals), interferential group (178 cases of benign colorectal disease or other non-colorectal tumors) and negative group (330 cases composed of healthy group and interferential group ) . The promoter methylation of fecal SDC2 and SFRP2 genes was detected by methylation-specific PCR (MSP) and compared with single gene methylation and the fecal immunochemical tests ( FIT) to evaluate its sensitivity and specificity. Results The stool sample analysis showed that the sensitivity of combined detection of SDC2 and SFRP2 in CRC group was 97. 73％ ( 129/132 ) , which was significantly higher than those of the single gene SDC2 test [ 70. 45％ ( 93/132) , P=0. 000] , single SFRP2 test [81. 82％ (108/132), P=0. 000] and FIT [69. 70％ (92/132), P=0. 000]. In adenoma group, the sensitivity of combined detection of SDC2 and SFRP2 was 57. 89％ (22/38), which was significantly higher than those of the single gene SDC2 test [ 15. 79％ ( 6/38 ) , P= 0. 000 ] and FIT [ 21. 05％ ( 8/38 ) , P=0. 021] , with no significant difference compared with that of SFRP2 test [ 47. 37％ ( 18/38) , P=0. 358] . In healthy group, the specificity of combined detection of SDC2 and SFRP2 was 98. 68％ (150/152), with no significant difference compared with those of single gene SDC2 test [ 100. 00％( 152/152) , P=0. 156] , single SFRP2 test [98. 68％ (150/152), P=1. 000] or FIT [95. 39％ (145/152), P=0. 091]. Specificities of combined detection of two genes in interferential and negative groups were 90. 45％ ( 161/178) and 94. 24％( 311/330) , which were significantly higher than 73. 03％( 130/178, P=0. 000) and 83. 33％( 275/330, P=0. 000) of FIT, respectively. Conclusion The combined detection test of methylation of SDC2 and SFRP2 is superior to single gene test, whose sensitivity of CRC and aggressive adenoma and specificity of distinguishing benign and malignant lesions are higher than FIT, which has potential application value.
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OBJECTIVE: A failed electrocardiography (ECG)-trigger often leads to a long acquisition time (TA) and deterioration in image quality. The purpose of this study was to evaluate and optimize the technique of self-gated (SG) cardiovascular magnetic resonance (CMR) for cardiac late gadolinium enhancement (LGE) imaging of rats with myocardial infarction/reperfusion. MATERIALS AND METHODS: Cardiovascular magnetic resonance images of 10 rats were obtained using SG-LGE or ECG with respiration double-gating (ECG-RESP-gating) method at 7T to compare differences in image interference and TA between the two methods. A variety of flip angles (FA: 10°–80°) and the number of repetitions (NR: 40, 80, 150, and 300) were investigated to determine optimal scan parameters of SG-LGE technique based on image quality score and contrast-to-noise ratio (CNR). RESULTS: Self-gated late gadolinium enhancement allowed successful scan in 10 (100%) rats. However, only 4 (40%) rats were successfully scanned with the ECG-RESP-gating method. TAs with SG-LGE varied depending on NR used (TA: 41, 82, 154, and 307 seconds, corresponding to NR of 40, 80, 150, and 300, respectively). For the ECG-RESP-gating method, the average TA was 220 seconds. For SG-LGE images, CNR (42.5 ± 5.5, 43.5 ± 7.5, 54 ± 9, 59.5 ± 8.5, 56 ± 13, 54 ± 8, and 41 ± 9) and image quality score (1.85 ± 0.75, 2.20 ± 0.83, 2.85 ± 0.37, 3.85 ± 0.52, 2.8 ± 0.51, 2.45 ± 0.76, and 1.95 ± 0.60) were achieved with different FAs (10°, 15°, 20°, 25°, 30°, 35°, and 40°, respectively). Optimal FAs of 20°–30° and NR of 80 were recommended. CONCLUSION: Self-gated technique can improve image quality of LGE without irregular ECG or respiration gating. Therefore, SG-LGE can be used an alternative method of ECG-RESP-gating.