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Objective:To explore the teaching effect of organ-system-based curriculum (OSBC) on cultivating the post competency of radiologists.Methods:Based on the teaching design of OSBC, our study has completed the teaching practice for imaging diagnosis of prostate diseases, focal liver lesions, small pulmonary nodules and intestinal obstruction. The imaging diagnosis of prostate diseases was taken as teaching point. Fifty-two trainees were divided into four groups: junior standardized residents and clinical-type postgraduates (JSRCP) group, senior grade of standardized residents and clinical-type postgraduates (SG-SRCP), advanced training radiologist (ATR) group, intern doctors (ID) group. The teaching framework of pre-training assessment, training and post-training test was designed, and the teaching effect and the operability evaluation of OSBC was compared in terms of test scores and subjective evaluation before and after the training. SPSS 18.0 was used for t test. Results:The test scores after training of four groups were significantly improved compared to the test scores before training. The test scores of SG-SRCP group and ATR group were significantly higher than those of ID group ( F=16.609, P<0.001). The results of subjective evaluation showed that the SG-SRCP and ATR group had the highest degree of satisfaction. Conclusion:OSBC education mode has a good training effectiveness of middle and advanced stages course of medical imaging. In the future teaching, OSBC teaching should be explored among different levels of students.
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Objective To investigate the clinical feasibility of using gemstone spectral image (GSI)technique to reduce the individual dose of contrast agent in performing lower extremity angiography.Methods Among the consecutive 75 patients receiving lower extremity CTA examination,60 patients were enrolled in this study.According to the scanning method and contrast dosage,the 60 patients were prospectively and randomly divided into the conventional CT routine-dose group (n=20),GSI routine-dose group (n=20) and GSI low-dose group (n=20).In the conventional CT routine-dose group and GSI routine-dose group,the dosage of contrast medium was 2 ml/kg and the injection rate was 3.5 ml/s.Scanning with 120 kVp and reconstruction with filter back projection (FBP) technology were used in the conventional CT routine-dose group,while scanning with spectrum mode and reconstruction with 50％ adaptive statistical iterative reconstruction (ASiR) technology were used in the GSI routine-dose group.In the GSI low-dose group,the dosage of contrast medium and the injection rate were 1.6 ml/kg and 2.8 ml/s respectively,and scanning with spectrum mode and reconstruction with 50％ ASiR technology were adopted.The target vessel CT values of three sets of images were determined,the contrast-to-noise ratio (CNR),the background noise (BN),the dose length product (DLP),the effective dose (ED),the iodine intake dose and the injection rate were calculated and compared between each other among the three groups.Single factor variance analysis and Bonferroni correction method were used to statistically analyze the results.By using Kruskal-Wallis test,the subjective scores of three sets of images were compared between each other among the three groups.Results According to exclusion criteria,60 patients were finally enrolled in this study.The images of GSI routine-dose group had the best CT value,CNR and BN (P＜0.01),but there was no statistically significant difference in BN between GSI routine-dose group and GSI low-dose group (P＞0.05).Both the CT value and CNR,except anterior tibial artery (P=0.162 and P=0.376 respectivcly),in the GSI low-dose group were higher than those in the conventional CT routine-dose group (P＜0.05).The ED values of both GSI groups were lower than that of the conventional CT routine-dose group (P＜0.01),although no statistically significant difference in ED value existed between the two GSI groups (P＞0.05).The iodine intake dose and injection rate of the GSI lowdose group were strikingly lower than those of the conventional CT routine-dose group and the GSI low-dose group (both P＜0.01).The subjective scores of three sets of images evaluated by two physicians were 82,95,90 points and 80,96,89 points respectively,the differences were statistically significant (H=14.954,P＜0.01;H=17.726,P＜0.01).GSI routine-dose group had the best image quality,and the image quality of GSI low-dose group was superior to that of conventional CT routine-dose group (P＜0.05).Conclusion Compared with conventional spiral CT scanning,gemstone optimal monochromatic imaging technique can obtain more optimal CNR and image quality,meanwhile,the radiation dose can be remarkably reduced while the imaging quality of lower extremity angiography can meet the requirements of making clinical diagnosis,moreover,individual intake of iodine can be reduced.
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Objective To evaluate the accuracy of chemical shift imaging (CSI) and MR spectroscopy (MRS) for fat quantification in phantom model. Methods Eleven phantoms were made according to the volume percentage of fat ranging from 0 to 100% with an interval of 10% . The fat concentration in the phantoms were measured respectively by CSI and MRS and compared using one-sample t test The correlation between the two methods was also analyzed. The concentration of saturated fatty acids ( FS), unsaturated fatty acids (FU) and the polyunsaturation degree (PUD) were calculated by using MRS. Results The fat concentration was (48.0 ±1.0)%, (57.0 ±0.5)%, (67.3±0.6)%, (77.3 ±0.6)%, (83.3±0.6)% and (91.0±1.0)% respectively with fat volume of 50% to 100% by CSI. The fat concentration was (8.3 ±0.6)%, (16.3 ±0.7)%, (27.7 ±0.6)%, (36.0 ±1.0)%, (43.5±0. 6)% and (56. 5 ±1. 0)% respectively with fat volume of 10% to 60% by MRS, the fat concentration were underestimated by CSI and MRS (P < 0.05 ), and had high linear correlation with the real concentration in phantoms ( CSI: r = 0. 998, MRS: r = 0.996, P < 0.01 ) . There was also a linear correlation between two methods (r = 0. 992, P < 0. 01 ) but no statistically significant difference ( pairedsamples t test, t = -0. 125 ,P = 0.903). By using MRS, the relative ratio of FS and FU in fat were 0. 15and 0. 85, the PUD was 0. 0325, respectively, and highly consistent with these in phantoms. Conclusion Both CSI and MRS are efficient and accurate methods in fat quantification at 7.0 T MR.