Analysis of clinical, pathological and CT features of epidermal growth factor receptor exon 19 and 21 mutations in lung adenocarcinoma / 中华放射学杂志

Objective:To investigate the clinical, pathological and CT characteristics of lung adenocarcinoma patients with epidermal growth factor receptor (EGFR) 19 and 21 exon mutations.Methods:Clinical, pathological and imaging data of 683 patients with lung adenocarcinoma in the First Affiliated Hospital of Chongqing Medical University from December 2012 to December 2020 were retrospectively analyzed. According to the gene mutation status, patients were divided into EGFR common loci mutation group (exons 19 or 21) with 382 cases (mutation group), including 19 exon mutation in 165 cases (exon 19 mutation subgroup) and 21 exon mutation in 217 cases (exon 21 mutation subgroup), and EGFR negative mutation group with 301 cases (negative mutation group). Independent sample t-test and χ 2 test were used to compare those features between mutation group and negative mutation group, exon 19 mutation subgroup and exon 21 mutation subgroup. The indicators with statistically significant differences in univariate analysis were included in binary logistic regression analysis to screen out independent predictors and establish the model. Receiver operating characteristic curve and area under curve (AUC) were used to evaluate the predictive performance of the model or index. Results:There were significant differences between mutation group and negative mutation group in gender distribution, smoking history, the proportion of solid-dominated growth pattern, peripheral distribution, tumor maximum diameter (3 cm as the cut-off point) distribution, spiculation, ground-glass opacity (GGO), air bronchogram, vascular convergence sign, pleural retraction, the number of lung metastases (10 as the cut-off point), pleural effusion, necrosis, and lymph node metastasis in lung adenocarcinoma patients ( P<0.05). The logistic regression showed that female (OR=5.230,95%CI 3.534-7.740, P<0.001), non-smoking history (OR=2.970, 95%CI 1.986-4.443, P<0.001), GGO (OR=3.092, 95%CI 1.746-5.477, P<0.001), absence of necrosis (OR=1.754, 95%CI 1.047-2.939, P=0.033), vascular convergence sign (OR=3.129, 95%CI 1.971-4.969, P<0.001), pleural retraction (OR=2.434, 95%CI 1.680-3.526, P<0.001), and the number of lung metastases≥10 (OR=2.242, 95%CI 1.284-3.915, P=0.005) were independent predictors of EGFR exon 19 and 21 mutations, and the AUC of the logistic model based on these predictors in predicting EGFR exon 21 and 19 mutations in lung adenocarcinoma was 0.804. There were significant differences between EGFR exon 19 mutation subgroup and EGFR 21 mutation subgroup in gender distribution, the proportion of acinar-dominated growth pattern, peripheral distribution, vascular convergence sign, pleural retraction ( P<0.05). The logistic regression showed that vascular convergence sign (OR=1.833, 95%CI 1.187-2.831, P=0.006) was independent predictor of EGFR exon 21, the AUC of vascular convergence sign for distinguishing EGFR exon 19 and EGFR 21 mutation was 0.604. Conclusions:There are some differences in the clinical, pathological, and CT features of patients between EGFR common loci mutation and EGFR negative mutations, EGFR exon 19 and exon 21 mutations in lung adenocarcinoma. Familiarity with these differences is helpful for the individualized treatment of patients with unknown gene mutation status of lung adenocarcinoma.

Countermeasures of "early clinical, multi-clinical and repeated clinical" for medical undergraduates / 中华医学教育探索杂志

In 2012, Chongqing Medical University was approved to be the first batch of pilot universities in China for excellent doctor education and training program, which started the exploration of "early clinical, multi-clinical and repeated clinical" for medical students, and put it into practice in clinical medicine of Batch 2015 ("5+3" integrated specialty). This paper applies the methods of literature research, questionnaire survey and empirical research to understand the needs and suggestions of students for clinical practice. It is suggested that the concept of "early clinical practice" should be integrated into the theoretical teaching, the teaching method of "case introduction" should be adopted in the course of integrated medicine education, the course of Clinical Skills should be reformed, the clinical practice activities such as "early admission to the ward" should be carried out, and the evaluation system of clinical practice should be rebuilt, hoping to provide references for the exploration of "early clinical, multi-clinical and repeated clinical" in medical education of other colleges and universities.

DTI observation on secondary degeneration of somatic sensation conduction fibers in patients with chronic thalamic infarction / 中国医学影像技术

Objective To observe DTI manifestations of secondary damage of the somatic sensation conduction fiber bundles in patients with chronic thalamic infarction (TI).Methods Routine MRI and DTI were obtained in 28 patients with unilateral chronic TI (TI group) and 28 healthy volunteers (control group).The fractional anisotropy (FA) value,mean diffusivity (MD) value,primary eigenvalue (λ1) and transverse eigenvalue (λ23) of both spinothalamic tract and central thalamic radiation were calculated,and statistical analysis was performed.Results Compared with those in control group,the FA value of spinothalamic tract and central thalamic radiations significantly decreased (all P＜0.001),while MD,λ1 and λ23 value significantly increased in TI group (all P＜0.05).Conclusion TI can not only result in damage in spinothalamic tract below the infarct,but also cause deterioration in central thalamic radiations above the infarct.Moreover,the secondary damage of spinothalamic tract and central thalamic radiations present the same DTI manifestations in the chronic period.

Quantitative analysis of energy spectrum CT in differential diagnosis of peripheral lung cancer and tuberculosis in unenhanced phase / 中国医学影像技术

Objective To investigate the value of quantitative analysis of spectrum CT in the differential diagnosis of lung cancer and tuberculosis in unenhanced phase.Methods Data of 51 patients with solitary pulmonary nodules or masses confirmed by pathology who underwent chest unenhanced spectrum CT were retrospectively analyzed.There were 36 cases of peripheral lung cancer (lung cancer group) and 15 cases of tuberculosis (tuberculosis group).The differences of 40～ 140 keV single energy CT value,shape and slope of energy spectrum attenuation curve,different base material of concentration values and effective atomic number (Eff-Z) between the two groups were compared.Results The single energy CT values of 40～70 keV in lung cancer group were higher than those in tuberculosis group (all P＜0.05),while no significant difference of the single energy CT values of 80～140 keV were found in both two groups (all P＞0.05).The shape of energy spectrum attenuation curve of lung cancer group was fast express reduction (36/36,100％).The energy spectrum attenuation curve of tuberculosis group showed walked straightly (11/15,73.33％) and back up type (4/15,26.67％).The slope of the energy spectrum attenuation curve in lung cancer group (K40～ 65 key,K65～90 kev,K90～140 kev)were higher than those in tuberculosis group (all P＜0.01).The calcium (water) concentration of lung cancer group was higher than that of tuberculosis group (P＜0.01),while the lipid (water) concentration of lung cancer group was lower than that of tuberculosis group (P＜0.01).The water (calcium) concentration in both groups was not statistically different (P=0.10).The Eff-Z of lung cancer group was higher than that of the tuberculosis group (P＜0.01).Conclusion The peripheral lung cancer and the tuberculosis have different energy spectrum CT quantitative parameters in unenhanced phase,which can provide valuable informations for diagnosis.

The value of quantitative analysis with spectral CT imaging in the diagnosis of non-small cell lung cancer with different pathological types / 中华放射学杂志

Objective To explore the value of quantitative parameters of spectral CT imaging in the diagnosis of non-small cell lung cancer (NSCLC) with different pathological types. Methods One hundred and thirty-six patients with NSCLC proved by pathology underwent chest plain and enhanced CT scan with gemstone spectral imaging (GSI) mode by Discovery CT750 HD, including 57 cases of squamous cell carcinoma (SQCC) and 79 cases of adenocarcinoma (ADC). All the cases were divided into two groups of tumor diameter>2 cm (120 cases, including 50 cases of SQCC and 70 cases of ADC) and diameter≤2 cm (16 cases, including 7 cases of SQCC and 9 cases of ADC). The slope between 40 and 65 keV(K40-65 keV) of spectral attenuation curve, effective atomic number (Eff-Z) and calcium concentration in plain scan (PS) and K40-65 keV of spectral attenuation curve, iodine concentration and water concentration in arterial phase (AP) of SQCC and ADC in the two groups were measured and compared respectively. Furthermore, all cases were classified according to the trend of spectral attenuation curve in PS. These quantitative parameters satisfying normal distribution were compared by two independent samples t test, while those parameters not satisfying normal distribution were compared by rank sum test. ROC curves was drawn for these parameters with statistical difference and area under the curve (AUC) was used to measure the differential diagnostic performance of each parameter. Chi square test was used to compare the differences of the trend of spectral attenuation curve in PS between SQCC and ADC. Results In the group of diameter>2 cm: (1) Comparison of quantitative parameters of spectral CT in PS:K40-65 keV, Eff-Z and calcium concentration of ADC were 0.69 ± 0.56, 7.76±0.19, and (4.11±2.93) mg/cm3, respectively. The corresponding parameters of SQCC were 0.19± 0.23, 7.59 ± 0.14, and (1.25 ± 1.59) mg/cm3, respectively. These parameters of ADC were significantly higher than SQCC (Z=-7.000,-6.249, t=-6.884, P0.05). The trend of spectrum attenuation curve in PS of all cases showed type Ⅱ. Conclusions Lung ADC and SQCC have different quantitative parameters in spectral CT imaging. These quantitative parameters are valuable in classifying the pathological type of NSCLC with diameter more than 2 cm.

Study on improving the standardized training resident radiologists' comprehensive ability in medi-cal teaching and research based on PACS retrospective case report presentation / 中华医学教育探索杂志

Picture archiving and communication system (PACS) was used to perform archiving and retrospective cases report presentation in resident radiologist standardized training, and the current conven-tional article reviewing case report presentation form was compared. The results showed the scores of quiz and questionnaire of using archiving and retrospective cases report based on PACS were higher than using the current conventional form (P<0.05). This type of case report presentation can improve overall capability of resident radiologist standardized training including imaging diagnose,research and educational skill.

Stage Ⅰ Central Lung Cancer and Bronchial Disseminated Pulmonary Tuberculosis: A Comparative Analysis of Tree-in-bud Sign at CT / 中国医学影像学杂志

Purpose To investigate the difference of imaging features of tree-in-bud (TIB) sign at CT between stage Ⅰ central lung cancer and bronchial disseminated pulmonary tuberculosis in order to reduce the misdiagnosis rate of central lung cancer.Materials and Methods 32 patients of stage Ⅰ central type lung cancer confirmed pathologically or clinically (lung cancer group) and 47 patients of bronchial disseminated pulmonary tuberculosis confirmed pathologically or clinically (tuberculosis group) underwent chest CT scanning and were found with TIB sign.The imaging data of all the cases were analyzed retrospectively in terms of distribution range,accompanying CT findings of TIB sign,and abnormalities of segmental and (or) larger bronchus proximal to it.Results TIB sign was mainly focal (unilobar) in lung cancer group (96.88％),while it was mainly diffuse (more than one pulmonary lobe) in tuberculosis group (80.85％).The difference was significant (P＜0.01).Accompanying CT findings:① Obstructive bronchial mucoid impaction distal to the TIB was more common in lung cancer group than in tuberculosis group (100％ vs 6.38％,P＜0.01).② Consolidation and/or ground-glass opacities were found both in lung cancer group (34.38％) and in tuberculosis group (48.94％).The difference was not significant (P＞0.05).③ Cavity was less common in lung cancer group than in tuberculosis group (0 vs 38.30％,P＜0.01).④ Nodules with diameter larger than 5 mm were much fewer in lung cancer group than in tuberculosis group (0 vs 76.60％,P＜0.01).TIB sign was found in 33 lobes in lung cancer group,and the abnormity was found in all these lobes (100％);while in tuberculosis group,TIB sign was found in 144 lobes and the abnormity was found in 56 lobes (38.89％).Conclusion TIB sign shows differences between stage Ⅰ central lung cancer and bronchial disseminated pulmonary tuberculosis.The TIB signs such as focal distribution,accompanied by bronchial mucoid impaction and abnormality of segmental or (and) larger bronchus may predict the high possibility of central lung cancer.

Technology improvement in establishing rabbit models of osteonecrosis of the femoral head induced by glucocorticoid and lipopolysaccharide / 中国组织工程研究

BACKGROUND:The rabbits were widely used as experimental animal models in the research on etiology and pathological mechanism of steroid-induced osteonecrosis of the femoral head. It is stil a valuable and realistic research topic to improve and to innovate the modeling technology nowadays. OBJECTIVE:To improve the modeling technology on osteonecrosis of the femoral head in rabbits induced by glucocorticoid combined with lipopolysaccharide, with the focus on its reduced mortality and the guaranteed successful rate of modeling. METHODS:A total of 28 New Zealand white rabbits were randomly divided into the control group (n=10) and improvement group (n=18). Models of steroid-induced osteonecrosis of the femoral head were established according to different methods. In the improvement group, rabbits were injected with sodium penicilin (5.0 mg/kg) and amikacin sulfate (1.63×104 U/kg) in the left gluteus muscle. Twenty-four hours later, al rabbits were injected with prednisolone acetate (20 mg/kg) in the right gluteus muscle. Forty-eighthours later, 5.0 μg/kg of lipopolysaccharide was intravenously injectedvia the ear. From then on, two injections of prednisolone acetate (20 mg/kg) were respectively performed alternately in the left and right gluteal muscle at an interval of each 24 hours. Sodium penicilin (5.0 mg/kg) and amikacin sulfate (1.63×104 U/kg) were intraperitonealy injected for 2 consecutiveweeks. In the control group, 10 μg/kg lipopolysaccharide was injectedvia the ear vein of rabbit. From then on, prednisolone acetate (20 mg/kg) was intramuscularly injected at an interval of each 24 hours, totaly three times. Benzylpenicilin sodium 20×104 U/rabbit was intramuscularly injected once a week. RESULTS AND CONCLUSION:Rabbit models of steroid-induced osteonecrosis of the femoral head were successfuly established in both groups. Compared with the control group, the mortality was significantly reduced after model establishment in the improvement group, and the bone lacuna and osteonecrosis of the femoral head were apparent. These findings indicated that the improved technology of model establishment of steroid-induced osteonecrosis of the femoral head could be used to aleviate the damage degree on the gluteal muscles, to guarantee the successful rate of modeling, and to noticeably reduce the mortality of rabbits.

Reform clinical skill training model to improve performance of objective structured clinical examination / 中华医学教育探索杂志

Objective To improve the mode of clinical medicine postgraduates for specialty degree by OSCE. Methods Clinical medicine postgraduates for specialty degree of Grade 2010 and 2011 were enrolled as research objects. The OSCE scores of the students of Grade 2010 were analyzed and the problems in clinical skills training were summarized. In the last year of clinical training for the clinical medical students of Grade 2011, the reform of clinical skills training was implemented with such improvement measures as publishing last year achievement, analyzing OSCE assessment, strength-ening the supervision of the department of clinical skill training, strengthening the examination as-sessment efforts and organizing collective training. And finally the OSCE scores of the students of Grade 2011 were compared with the scores of the students of Grade 2010. SPSS 19.0 was used to analyze the OSCE scores. Quantitative data were expressed as x±s. T test and Chi-squared test were em-ployed to do statistical analysis, with the inspection level of α=0.05. Result The graduate exami-nation OSCE scores of clinical medicine professional master's degree postgraduates of Grade 2010 display that the failure rate of SP, Physical, Surgical Operation, CPR and Case analysis are more than 5%. After the improvement of clinical skill training, using independent samples t test and chi square test, and contrasting grade 2010, the failure rate of the OSCE score of Grade 2011 in physical examination, surgical operation, site emergency station, CPR station, and case analysis station is significantly improved (P<0.05). Conclusions Improving the mode of clinical skill training by OSCE and performance analysis can effectively enhance clinical competence.

Comparison between ADC and standardized ADC value in diagnosing malignancy degree of prostate cancer / 重庆医学

Objective To compare the value of apparent diffusion coefficient (ADC) value and the standardized apparent dif‐fusion coefficient (ADC) value in diagnosing malignancy degree of prostate cancer .Methods Diffusion weighted imaging (DWI) results of 34 patients with prostate cancer proved pathologically were retrospectively analyzed .The ADC values in 49 lesions and normal peripheral zones of the prostates of the patients were measured .Then ,ADC values of the lesions were calculated .According to the results of Gleason score ,the lesions were divided into 3 groups:Gleason score≤6 (low‐risk group) ,Gleason score=7 (inter‐mediate‐risk group) and Gleason score≥8 (high‐risk group) .Statistical analysis was performed to evaluate the differences of the ADC values and sADC values in three groups ,and to evaluate the correlation between Gleason score and ADC value or sADC value . Results There were statistically differences overall in ADC values and sADC values of the three groups (P 0 .05) ,however ,there were difference between sADC values of three groups each other (P0 .05) .However ,when change the specificity to 100% ,sADC had higher sensitivity than ADC values (47 .5% vs .5 .6% ,78 .2% vs .50 .9% ) in differentiating low‐risk from inter‐mediate‐risk group ,and low‐risk from high‐risk group .Conclusion ADC value and sADC value showed all negative correlation with Gleason score ,but sADC value may be of higher performance in diagnosing malignancy degree of prostate cancer .

Design and application of the telemedicine system / 重庆医学

Objective In response to the requirements of the new nation health care reform for the first diagnosis sinking .To in‐vestigate hospital as the center ,radiation surrounding ,we build the telemedicine system .Methods We analyzed the requirement ,de‐sign the architecture of the system through the way of TOGAF .Results The telemedicine system including telemedicine ,remote diagnosis and distance education was built .Conclusion The design ,establishment and application of the telemedicine system has an important influence and meaning .

Exploration on the role-play of medical students as standardized patients / 中华医学教育探索杂志

Utilizing standardized patient(SP) for classroom simulation is common in current medical education. In this paper, incentive measures and combination of SP with theoretical examination, simulated people and clinical practice were proposed after in-depth analysis of advantages and disadvan-tages of using medical students as SP in terms of recruitment, training, and application. All these mea-sures were intended to promote the development of simulative medical education that in turn to cultivate students to be competent in practice.

New training model for clinical medical postgraduates with scientific degree / 中华医学教育探索杂志

Postgraduate education is the highest leveled education in the national education hierarchy and bears the historic task of providing top-notch innovative personnel for the country and conducting independent innovation. At present,the medical degree is divided into two types: clinical scientific degree and clinical professional degree. Clinical scientific degree is different from clinical professional degree due to its importance and peculiarities. Therefore,education for postgraduates with clinical scientific degree faces many problems in enrollment,research and clinical capacity develop-ment and evaluation system. Through reforming enrollment plan,strengthening capacity building and establishing sound clinical education evaluation system can further improve training quality for post-graduates with clinical scientific degree.

Quantitative study of the cervical spinal cord damage in patients with multiple sclerosis and neuromyelitis optica using diffusion tensor imaging / 中华放射学杂志

Objective To investigate the changes of the cervical spinal cord in patients with relapsing-remitting multiple sclerosis (RRMS) and relapsing neuromyelitis optica (RNMO) using diffusion tensor imaging (DTI) and to analyze its correlations with clinical disability scores.Methods Thirty patients with MS (MS group),28 patients with NMO (NMO group) and 20 healthy volunteers were imaged using DTI on a 3.0 Tesla scanner.DTI indices of cervical spinal cord from all participants were measured,including mean diffusivity (MD) and fractional anisotropy (FA),and the correlations between the DTI metrics and the expanded disability status scale (EDSS) scores were assessed.One-way ANOVA,Dunnett-t test and Spearman correlation analysis were used for statistics.Results (1) The values of MD among three groups were different at C3 level for left lateral and dorsal columns,C4 level for the central gray substance and dorsal columns,and C5-C6 level for all structures.There were significant differences among them (F =4.006-36.814,P ＜ 0.05).The values of FA were significantly different at all levels (F =5.561-98.128,P ＜0.05).(2) Compared with the control group,the values of MD were increased and FA were decreased for both MS and NMO groups,there were significant differences among them (t =-0.320-3.138,P ＜0.05).In MS and NMO groups,there were no significant differences of MD (t =-1.183-0.069,P ＞0.05),while the FA at C4-C6 levels (including the central gray substance,dorsal columns,right lateral columns and left lateral columns) for NMO group were 0.57 ± 0.09,0.56 ± 0.11,0.54 ±0.10,0.57±0.09,0.55 ±0.11,0.52 ±0.13,0.55 ±0.11,0.54 ±0.13,0.54±0.10,0.54±0.11,0.53 ±0.13,0.52 ±0.11 ;and for MS group were 0.67 ±0.10,0.68 ±0.10,0.68 ±0.10,0.70 ±0.12,0.68 ±0.11,0.69±0.10,0.68 ±0.11,0.69 ±0.12,0.67 ±0.14,0.68 ±0.15,0.69 ±0.14,0.69 ±0.16,and there were significant differences between two groups (t =-0.011-0.169,P ＜ 0.05).(3)Univariate correlations between DTI measures and the average EDSS scores were assessed.The MD at all levels showed significant positive correlations with disability scores (r =0.324-0.541,P ＜ 0.05),and FA significant negative correlated with disability scores (r =-0.632--0.294,P ＜ 0.05),except C4 level for lateral columns and C2 level.Conclusions DTI metrics are sensitive to cervical spinal cord damage in demyelinating diseases,providing an important way of distinguishing MS from NMO,and can be potentially useful quantitative biomarkers for monitoring the evolution of demyelinating diseases.

Practice quality engineering,push dominant profession and promote teaching quality / 中华医学教育探索杂志

‘Quality engineering’is the important measure to deepen teaching reformation and upgrade teaching quality in new period.During the practice of‘quality engineering’,our hospital completed six basic works including building special professions as the core,making exquisite courses,teaching team,bilingual demonstration courses and teaching material as the supports as well as taking leaders'high emphasis,organization construction and implementation of supporting documents as the guarantee,thus to push forward dominant professions and promote teaching qualities.

The clinical application of hydrogen magnetic resonance spectroscopy combining with diffusion weight imaging in brain gliomas grading / 生物医学工程学杂志

The present study was aimed to investigate the function of diffusion weight imaging (DWI) combining with magnetic resonance spectroscopy (MRS) in the grading of brain gliomas. 12 cases low grade and 17 cases high grade of brain gliomas patients were examined with DWI and MRS, with all tumors confirmed by pathology in advance. The apparent diffusion coefficient (ADC) values, their corresponding metabolite ratios of Cho/Cr, Cho/NAA and tumor cellularities of tumor solid enhanced parts were measured. The ratios of Cho/Cr and Cho/NAA and their corresponding ADC values had significant differences between their high and low grade gliomas values, respectively. The ADC values demonstrated a negative correlation with Cho/Cr, Cho/NAA, and a significant negative correlated with Cho/Cr. And the ADC values demonstrated strong negative correlations with tumor cellularities. DWI combining with MRS could provide more valuable information in evaluating gliomas grading.

Magnetic resonance spectroscopy in observing thalamus metabolism of patients with multiple sclerosis or neuromyelitis optica / 中国介入影像与治疗学

ObjectiveTo investigate the variation of thalamus metabolism in patients with multiple sclerosis (MS) or neuronmyelitis optica (NMO) using 1H-MRS.Methods1H-MRS was performed to 32 MS patients (MS group),28 NMO patients (NMO group) and 35 healthy volunteers (normal control group).The ratios of metabolism in thalamus,including N-acetylaspartic acid/creatine (NAA/Cr),choline/creatine (Cho/Cr) and myo-inositol/creatine (mI/Cr) were calculated and compared.ResultsThere was statistical difference of NAA/Cr in thalamus among the three groups (P＜0.05).NAA/Cr in thalamus of MS group was significantly lower than that of normal control group (t= -3.45,P＜0.05),while no statistical difference of Cho/Cr and mI/Cr was found (t=0.086,0.661,all P＞0.05).No statistical difference of NAA/Cr,Cho/Cr or ml/Cr was found between NMO group and normal control group (t=-0.792,1.408,1.735,all P＞0.05).Conclusion1H-MRS shows the decrease of thalamus NAA/Cr that suggesting axon damage in MS patients,but in NMO patients no same result is found.1 H-MRS can reflect the pathological changes of MS and NMO,and improve the differential diagnosis of the two diseases.

Analysis and solution of the current situation of teaching ability in teaching hospital / 中华医学教育探索杂志

With the development and the expansion of higher medical education,lack of course resource became a “bottleneck” which restricted the development of medical schools.Teaching hospitals played some roles in medical education,but there was a huge gap in teaching ability between these hospitals and the hospitals affiliated with universities.The Clinical College analyzed the current situation of teaching ability in teaching hospitals and did the preliminary research for the solutions of this situation.

The measurement of organic radiation dose of multi-slice CT scanning by using the Chinese anthropomorphic chest phantom / 中华放射学杂志

Objective Using the Chinese anthropomorphic chest phantom to measure the absorbed dose of various tissues and organs under different noise index, and to assess the radiation dose of MSCT chest scanning with the effective dose(ED). Methods The equivalence of the Chinese anthropomorphic chest phantom(CDP-1C) and the adult chest on CT sectional anatomy and X-ray attenuation was demonstrated. The absorbed doses of various tissues and organs under different noise index were measured by laying thermoluminescent dosimeters(TLD) inside the phantom, and the corresponding dose-length products(DLP) were recorded. Both of them were later converted into ED and comparison was conducted to analyze the dose levels of chest CT scanning with automatic tube current modulation (ATCM) under different noise index. Student t-test was applied using SPSS 12.0 statistical software. Results The Phantom was similar to the human body on CT sectional anatomy. The average CT value of phantom are -788.04 HU in lung,45.64 HU in heart,65.84 HU in liver,254.32 HU in spine and the deviations are 0.10%,3.04%, 4.49% and 4.36% respectively compared to humans. The difference of average CT value of liver was statistically significant(t=-8.705,P＜0.05),while the differences of average CT values of lung, heart and spine were not significant(t value were -0.752,-1.219,-1.138,respectively and P＞0.05).As the noise index increased from 8.5 to 22.5, the DLP decreased from 393.57 mGy·cm to 78.75 mGy·cm and the organs dose declined. For example, the average absorbed dose decreased from 22.38 mGy to 3.66 mGy in lung. Compared to ED calculating by absorbed dose, the ED calculating by DLP was lower. The ED values of the two methods were 6.69 mSv and 8.77 mSv when the noise index was set at 8.5. Conclusions Application of the Chinese anthropomorphic chest phantom to carry out CT dose assessment is more accurate. The noise index should be set more than 8.5 during the chest CT scanning based on ATCM technique.

Effusion quantification in the knee cavity and peripheral synovial bursa: MRI determination / 中国组织工程研究

BACKGROUND: MRI is a gold standard for imaging diagnosis of knee joint disease, but it cannot accurately quantitate effusion of knee.OBJECTIVE: To investigate different volume of contrast-medium in the cavity of knee with MRI scanning to provide objective evidence and quantitaive standard for clinical diagnosis of effusion in the cavity of knee.DESIGN, TIME AND SETTING: Quantitative observation was performed in the MRI Room, the First Affiliated Hospital of Chengdu Medical College from October to December 2008.MATERIALS: Ten samples of fresh normal adult knee joint.METHODS: Puncture with the needle retaining in the cavity of knee of normal adult corpse without effusion or pneumatosis was performed, and 1, 5, 10, 15, 20, 30, 40 mL contrast-medium was injected into the cavity. Coronal section, vertical plane and transect were scanned with T2WI, 4 mm thickness and 1 mm interval by MRI.MAIN OUTCOME MEASURES: The distribution of different amounts of contrast agent in the knee cavity and peripheral synovial bursa in knee coronal plane and sagittal cross-sections.RESULTS:?MRI scanning from coronal section: after 10 mL contrast-medium injection, in the center of medial knee joint, high visual signal was seen in the cavity of joint; after 15 mL contrast-medium injection, scanning between femora and patella, high visual signals were observed; after 20 mL contrast-medium injection, scanning by posterior internal and external condyle of knee, high visual signals were found in 80% of internal and external recess of posterosuperior of thighbone.?MRI scaning at 1.5 cm from internal vertical plane of middle knee: after 5 mL contrast-medium injection, high visual signal area appeared in intercondylar eminence, narrowing gradually, and 70% of posterosuperior internal condyle of tibia; after 10 mL contrast-medium injection, high visual signals appeared at the 1/3 point under suprapatellar bursa; after 15 and 20 mL contrast-medium injection, high visual signal appeared in 80% of 1/3 point of suprapatellar bursa; after 30 and 40 mL contrast-medium injection, high visual signal was seen both internal and external recess of posterosuperior knee.?MRI scanning from inframarginal Apex of patella of knee transect: after 5 mL contrast-medium injection, high visual signal appeared in 90% area at 1/3 point posterior articular cavity; after more than 10 mL contrast-medium injection, high visual signal was seen in 70% area of anterior thighbone facet. CONCLUSION: By injecting different volumes of contrast-medium into the knee cavity and peripheral synovial bursa, reference standard can be constructed according to different volumes of effusion, which is significant for diagnosis of effusion of knee cavity and peripheral synovial bursa with MRI.