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Objective:To explore the application effect of case-based learning (CBL) in teaching magnetic resonance imaging (MRI) for non-imaging clinical professional postgraduates.Methods:Eighty non-imaging clinical professional postgraduates who had standardized residency training from 2017 to 2019 were selected as the participants and were randomly divided into two groups, experimental group and control group. The experimental group adopted CBL, and the control group adopted traditional teaching mode. After the standardized training in the radiology department, the differences in image reading scores, theoretical scores and course evaluation were compared between the two groups. SPSS 25.0 statistical software was used for analysis. Independent t test was used for the measurement data of normal distribution, Mann-Whitney U test was used for the measurement data of skewed distribution, and categorical variables were compared by chi-square test. Results:In the reading scores of MRI, the scores of the experimental group and the control group were (82.53 ± 5.72) points and (77.38 ± 6.14) points respectively, and the number of students in the experimental group whose reading scores were between 80-100 segment was 63.6% higher than that in the control group, with significant differences between the two groups ( P < 0.001), but without significant differences in theoretical average scores between the two groups ( P > 0.05). In addition, in the course evaluation, except for the index of learning burden, there were significant differences in other indexes between the experimental group and the control group ( P < 0.05). Conclusion:In the teaching of MRI, the application of the CBL helps non-imaging clinical professional postgraduates improve their MRI diagnostic thinking and independent reading ability.
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Objective To investigate the effects of X-ray beam hardening from contrast agent on CT values on CTA images.Methods The 20 mL syringes were numbered 1 to 26.The syringe 1,4,7,23 and 20 were filled with 1 mL,0.8 mL,0.6 mL,0.4 mL and 0.2 mL of iodine contrast medium (300 mg I/mL),respectively,and then mixed each of them with 0.9％ NaC1 solution to get a total of 20 mL solution in each syringe.The rest of 26 syringes were filled with 20 mL of 0.9％ NaC1 solution,as the experimental group to simulate carotid artery CTA examination.Matched 26 numbered syringes were filled with 20 mL 0.9％ NaC1 solution respectively,as control group to simulate plain scan.CT scans were performed,CT values were measured,and then the difference of CT values of 0.9 ％ NaCl solution in two groups was analyzed statistically.Results The mean,maximum and minimum CT values of saline in the experimental group vs control group were (-0.139±10.322) HU vs (5.585±2.939) HU,14.6 HU vs 9.7 HU,-23.8 HU vs-2.4 HU,respectively,and the differences were significant (t=2.695,P＜0.05).The CT values of saline around the high concentrations of iodine solution showed a large fluctuation range.Conclusion The X ray beam hardening effects caused by high concentration of iodine contrast on carotid artery CTA phase,may cause significant fluctuations of CT values.
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Objective To investigate the value of multiple parameter analysis in spectral CT scanning for the diagnosis of pulmonary nodules or masses.Methods The spectral CT scanning data in arterial phase of 319 patients with pulmonary nodules or masses confirmed by pathology and/or follow-up were analyzed retrospectively.The patients were divided into 3 groups:inflammatory group,lung cancer group and tuberculosis group.The Iodine(water)concentration,water(Iodine)concentration,the effective atomic number and the CT value of 60,70 and 80 keV single energy in the leisons were measured.One way A NOVA and LSD-t test were used for statistical analysis.Results One way A NOVA showed that the Iodine(water)concentration,water(Iodine)concentration,the effective atomic number and the CT value of 60,70 and 80 keV single energy among 3 groups in the arterial phase were all statistically different(P<0.05).T he LSD-t test showed there were statistical differences of Iodine content and effective atomic number between tuberculosis group and inflammatory group,lung cancer group and inflammation group(P<0.05).There were statistical differences between tuberculosis group and lung cancer group,inflammation group and lung cancer group in water concentration(P<0.05).The statistical differences in CT value of 60,70 and 80 keV single energy between tuberculosis group and inflammatory group,inflammation group and tuberculosis group were also found(P<0.05).Conclusion Multiple parameter analysis of spectral CT scanning in arterial phase could attribute to the diagnosis and differential diagnosis of pulmonary nodules or masses.
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Objective To investigate the value of the adaptive statistical iterative reconstruction (ASIR) algorithm for reducing the radiation dose and optimizing the image quality in the low-dose spectral CT scanning in GSl (Gemstone spectral imaging) of the liver.Methods A total of 60 patients who underwent hepatic spectral CT scanning in GSI were enrolled in this study.The patients were randomly divided into two groups according to priority with 30 cases per group.Low-dose spectral CT scanning was used for group A, and images were reconstructed by ASIR 0 and 50％ , marked as A1 and A2.Group B was scanned with conventional dose of spectral CT, and images were reconstructed by Filtered back projection (FBP).Effective doses (E) for each group were calculated.Image quality was assessed by two radiologists, and the radiation doses were compared between groups A and B.Results All image quality of each group were good enough for clinical diagnosis.E for group A and B were (3.2 ±0.2) and (5.8 ± 0.2) mSv, respectively.There was statistical difference with image noise between group A and B(Z =-6.784,P ＜ 0.05).The image noise, SNR and CNR had statistical differences between group A and B (F =24.013, 15.646, 8.285, P ＜0.05).Compared with group A1, the image noise was lower, and the SNR and CNR were higher in groups A2 and B(P ＜ 0.05).There were no statistical differences of image noise, SNR and CNR between groups A2 and B (P ＞ 0.05).There were no statistical differences of the image quality score between groups A1, A2 and B (F =102.38,105.768, P ＜ 0.05).Conclusions ASIR combined with low-dose spectral CT scanning was helpful to reduce radiation dose and could obtain better image quality in hepatic CT examination.
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Objective To explore a safe and effective hyperthermia interventional therapy temperature for hepatic carcinoma. Methods Eight swines were divided into four groups according to trans-arterial hyperthermic perfusion temperature, 45 ?C , 50 ?C ,55 ?C , and 60 ?C (catheter flowing temperature) groups. The hepatic and renal functions and blood coagulation function were examined before and after the procedur and then all swines were sacrificed and the livers were pathologically analysed,simultoneously with the evaluation of the safe hyperthermic temperature 35 hepatic carcinomas were carried out under this interventional hyperthermochemotherapy via the arterial catheter (80 cm, 5F) placed into the tumoral artery with the perfusion agents warmed to 60～65 ?C (catheter flowing temperature was 47.55?0.44 ?C ). Results The hyperthermic coagulation necrosis, hepatic dysfunction level and fever were found after 55 ?C and 60 ?C hyperthermic perfusion while those of 45 ?C and 50 ?C groups basically remained normal. The tumor growth rate and total efficacy rate were -(0.35?0.32) and 79.2%, respectively, and 0.5, 1, 1.5 year survival rates were 100%, 80%, 60% respectively after follow-up. The adverse effects of the interventional hyperthermochemotherapy was similar to the routine TACE. Conclusions 45 ?C and 50 ?C (catheter flowing temperature) hyperthermochemotherapy for hepatic carcinoma is safe and effective.
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Objective To investigate the factors related to the heating effect by transarterial catheter hyperthermic infusion with the evaluation of the feasibility in controlling the tumor temperature.Methods Infusing 55-68℃ liquid at the speed of 10-40 ml/min through 6F,5F or 3F catheter with different length respectively under the similar clinical condition.The liquid temperature at the terminal exit of the catheter was measured with a digital thermometer.The factors related to the liquid temperature at the exit of the catheter were analyzed by multiple regression analysis. Results The infusion temperature,rate and the catheter length were the main related factors to the liquid temperature at the exit of the catheter as the condition similar in clinical use.When 60-65℃ liquid was infused at the rate of 20-40 ml/min through 5F catheter with length of 80 cm,the mean and 95% confidencial interval of the liquid temperature at the chetheter exit were(47.55?0.44)℃ and 44.61-48.49℃ respectively.Conclusions The liquid temperature at the exit of infusion catheter can be regulated and controlled through adjusting the liquid perfusion temperature and speed.
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Objective To evaluate mini-dose pre-injection test in the use of contrast-enhanced magnetic resonance angiography (CEMRA), and to inspect the possibility of contrast medium peak-time prediction by age, body weight and heart rate.Methods The data from mini-dose pre-injection test of contrast medium before vertebral artery CEMRA were retrospectively reviewed in 55 patients. The linear correlation and regression of the data including age, body weight, heart rate, and the reaching-time, peak-value-time, duration and peak-value-signal of contrast medium was performed by using SPSS software.Results The age (n=55, =62 years old, M=59 years old), body weight (n=55, = 63 kg), heart rate (n=40, =73 beats per minute), peak-value-time (n=55,=17.5 seconds), peak signal intensity (n=55,=472), and duration of contrast (n=49,=10.35 seconds)were analyzed. No statistically significant correlation existed between peak-value-time of contrast medium and the age (r=0.231, t=1.728, P=0.090), body weight (r=0.118, t=0.865, P=0.392), and heart rate (r= -0.046, t=-0.284, P=0.776). The peak-value-time correlated negatively with peak signal intensity (r=-0.322, t=-2.56, P=0.016)and positively with duration of contrast (r=0.658, t=5.99, P=0.000). The peak signal intensity was negatively correlated with body weight(r=-0.356, t=-2.77, P=0.008). The linear regression analysis show b=-0.284, t=-2.285, P=0.026 between peak-value-signal and peak-value-time, b=-0.322, t=2.590, P=0.012 between peak-value-signal and body weight.Conclusion Mini-dose pre-injection test was more helpful to adjust the rate of contrast medium injection and determine the time delay during scanning. But the prediction of contrast peak-time based on age, body weight and heart rate was unreliable.
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Objective To investigate the dynamic change of T-lymphocyte subsets in the patients of liver cancer treated with intra-arterial hyperthermia chemoembolization (IHCE). Methods Sixteen patients of hepatic cancer were treated with IHCE. One or two weeks before and after the procedure, the blood samples were collected for evaluation of the peripheral blood T-lymphocyte subsets using flow cytometry in 16 cases. The results were compared with those of other 18 patients received routine transcatheter arterial chemoembolization (TACE) during the same period. Results The cases of IHCE group showed that the proportion of CD4 cells was increased and that of CD8 cell was decreased after 2 weeks of the treatment, so that the ratio of CD4 to CD8 was obviously higher than that of the control group (P=0.01). Conclusion The hyperthermia effect of IHCE can further enhance immune function of the patients with liver cancer.
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Objective To investigate the appearance,causes and countermeasures of the image artifacts in a computed radiographic system.Methods Random 1968 CR images were analyzed by GE Radworks.Results Among the 1,968 images which were choosed at random,66 images with artifacts were found and processed.The artifacts in computed radiographic system are relevant to system software and hardware,dust as well as operators.Conclusion Familiarization with the appearance and causes of CR image artifacts helps to prevent or reduce artifacts.
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0.05). Conclusions Transcatheter arterial thermochemoembolization combined with hepatic arterial infusion of Tween-80 is an effective and safe method in treating metastatic hepatic carcinoma.