Objective To explore the value of low field intensity MR GET2*WI in the diagnosis of meniscus injury.Methods 40 patients with knee injury were examined by various sequences of low field intensity MR to show meniscus.The results of surgery or arthroscopy were acted as diagnostic gold standard of meniscus tear,all samples were confirmed by pathology.Results The sensitivity,specificity and accuracy in diagnosing meniscus tear was 95.65%,92.86% and 94.32% by GET2*WI,and 84.78%,85.71% and 85.23% by FSET2WI respectively.Conclusion Low field intensity MR GET2*WI can show meniscus clearly,it is of significant in the diagnosis of meniscus injury

Objective To explore the CT characteristics of mucinous cystadenocarcinoma of appendix.Methods The CT findings of 5 patients with mucinous cystadenocarcinoma of appendix proved by surgery and pathology were analyzed retrospectively,and the corresponding literatures were also reviewed.Results All lesions in 5 patients showed cystic changes in the right hypogastrium inclu-ding irregular shape with lobulation in 4 and tubular shape in 1.The maximum traverse diameters ranged from 27 mm to 146 mm. Unclear boundary was showed if the lesion invaded the adjacent gut.The cystic wall was asymmetry and thickened with little nodes and nipple in the inner wall.The thick septa were seen in 3 tumors.Much mucus was seen in tumors with uneven density and average CT value of 1 9.3 HU-34.6 HU.On enhanced CT,obvious enhancement of the cystic wall and septa in 4 and moderate enhance-ment in 1 was showed.The adjacent fatty gap of 3 tumors were clear,however it was vague when accompanied with acute inflamma-tion.Small calcification in 3 and enlarged lymphatic nodes in 3 were also found.Conclusion CT shows some characteristics of mu-cinous cystadenocarcinoma of appendix and plays an important role in the diagnosis of the disease.

Objective To observe the relationship between diffusion-weighted imaging ( DWI) characteristics and chemoradiotherapy response in recurrence patients with radical hysterectomy .Methods 26 recurrence patients with radical hysterectomy were included .All underwent conventional MRI and DWI before and after chemoradiotherapy . Baseline tumor characteristics including recurrence site ,gross tumor volume ,necrotic area and the ADC value were re-corded.Focal regions of restricted diffusion were delineated as a separate ROI and ADC value was determined .Ima-ging features were compared between complete response group and partial response group .Results 12 patients had complete response ( CR group ) ,14 patients had partial response ( PR group ) .ADC valueafter chemoradiotherapy was significantly higher than that before chemoradiotherapy in PR patients .Compared with CR group ,PR group had a grea-ter gross tumor volume ,higher ADC value and more focal regions of restricted diffusion .Recurrence type and necrotic areas was no significant differences .Conclusion ADC value and focal regions of restricted diffusion adquired by DWI help to determine chemoradiotherapy response in recurrence patients with radical hysterectomy ,which is helpful for clinicians to predic treatment effect early .It has great significance for developing reasonable programs and impro-ving the therapeutic effect .

Objective To explore the diagnositic value of dual-phase contrast enhancement CT combined with virtual non-enhanced images by dual-energy CT in clear cell renal cell carcinoma.Methods Sixty patients who were suspected of clear cell renal cell carcinoma underwent non-enhanced CT and contrast enhancement CT of early interface-phase between cortex -medulla and parenchymal phase on a dual-energy CT.The true non-enhanced kidney CT(TNCT) was performed in a single-energy acquisition mode,but the dual-phase contrast enhancement CT were performed in a dual-energy mode of 80 kV and 140 kV respectively.The virtual non-enhanced CT ( VNCT ) images were derived from the data of early interfacephase using liver virtual non-contrast software.The diagnosises according to VNCT combined dual-phase contrast enhancement CT and dual-phase contrast enhancement CT only were made respeetively and compared with x2 test.Between the true non-contrast CT and the virtual non-contrast CT,the image quality was compared with Wilcoxon test ; The radiation dose of volume CT dose index ( CTDlvol ) and dose length product(DLP) in a single-phase and total examination,the mean CT HU values of the tumours werecompared with t test.Results The accuracy of VNCT combined dual-phase contrast enhancement CT was higher than that of dual-phase contrast enhancement CT only [93.3％ ( 56/60 ) vs.78.3％ ( 47/60 ) ; x2 =5.6,P ＜0.05].The detective ability (score) of VNCT was near to that of TNCT and the difference was not obvious( Z =0.00,P ＞ 0.05 ). The radiation dose of volume CT dose index ( CTDIvol ) and dose length product(DLP) in a single phase and total examination of VNCT[(8.85 ± 1.28) mGy,(196.45 ±21.12) mGy·cm,(17.69±2.35) mGy,(392.90±42.25) mGy · cm] were lower than that of TNCT [( 10.20 ± 1.44 ) mGy,( 218.29 ± 29.60 ) mGy · cm,( 30.61 ± 3.27 ) mGy and ( 654.86 ± 88.81 ) mGy ·cm],t =4.21,3.58,23.63,16.12 respectively,P ＜0.05.The mean CT HU values of tumours on VNCT images was higher than that on TNCT images and the difference was significant [(39.37 ± 6.35 ) vs.(34.94 ± 7.00 )HU,t =- 14.39,P ＜ 0.05].Conclusions The diagnositic value of dual-phase contrast enhancement CT combined virtual non-enhanced CT by dual-energy CT for clear cell renal cell carcinoma was obvious,most tumours can be diagnosed correctly,and the radiate dose can be decreased obviously,the normal single-energy non-enhanced and contrast enhancement CT might be replaced in the future.

Objective To analyze the CT manifestation and clinical characteristics of appendiceal mucinous tumor for improving the diagnostic and therapeutic level. Methods The CT and clinical data of 7 patients with appendiceal mucinous tumor verified by histopathology were retrospectively analyzed. Results Among the 7 cases, mucinous cystadenomas was in 6 cases, and mucinous cystadenocarcinoma was in 1 case. One case had no obvious discomfort;3 cases visited because of pain on right hypogastrium and fever;3 cases had the medical history ofchronic appendicitis, among whom 2 cases had the mass on right hypogastrium which had existed for 1 day or 2 years. The unenhanced CT showed that all of 7 cases had the cystic tumors on right hypogastrium near the cecum, and the maximum traverse diameter was 25-208 (67 ± 27) mm. The cyst walls of mucinous cystadenoma in 6 cases were flimsy, symmetrical, 2.3-3.5 mm thickness and smooth. Three cases had cyst walls calcification; the cyst wall of mucinous cystadenocarcinoma was thick and asymmetrical, and the thickness of cyst wall was 3.5-5.7 mm. Small nodes could be found inside the walls. 7 cases had much mucilage, with CT value 14.0-33.5 HU. Four cases had slight septa. The enhanced CT showed that the cyst walls of mucinous cystadenoma in 6 cases were mild to moderate continuous enhancement during venous phase; the cyst wall and nodes mucinous cystadenocarcinoma was obvious and continuous enhancement. Four cases showed clear boundary, while 3 cases accompanied with acute inflammation showed dim edge. The enlargement of lymphatic nodes could be seen near mesentery in 1 case. All the 7 cases were treated by surgical treatment. One patient who survived after 26 months showed the metastasis of peritoneal pseudomyxoma after 20 months. The 6 patients with mucinous cystadenoma were followed up for 18 - 36 months, they did not had metastasis or recurrence by CT review. Conclusions Appendiceal mucinous tumor is often short of characteristic in clinical symptom and physical sign, but has favourable prognosis. CT is a vital tool for its diagnosis and identification.

OBJECTIVETo analyze the CT and MRI findings and pathological characteristics of retroperitoneal localized Castleman's disease and discuss the diagnostic and differential value of CT and MRI.

METHODSCT, MRI and clinical data of retroperitoneal localized Castleman's disease, proved by surgery and pathology, of 13 patients were reviewed. Among them, all the 13 cases received CT, and 4 cases received MRI examination.

RESULTSAmong the 13 cases, 12 cases were of hyaline vascular type, and one was of mixed type. All foci were single mass and most foci located in the periphery of the kidney. The maximum diameter was 4.2 cm to 8.6 cm and the mean diameter of all tumors was 5.9 cm. The outline of most tumors was clear and kidney-shaped. On unenhanced CT, 10 cases showed low density and 3 cases showed isodensity. On plain MRI, four cases showed iso-signal on T1WI, three cases showed slightly high signal on T2WI and one showed moderately high signal. The CT and MRI findings were similar on contrast enhanced scan. In arterial phase, 10 cases showed moderate enhancement, 2 cases showed significant enhancement and one case showed moderate enhancement. Five cases showed rather homogeneous enhancement and 8 cases showed heterogeneous enhancement.In venous phase, all the 13 tumors showed continuous enhancement. Eight cases showing heterogeneous enhancement in arterial phase showed expanded range, and among them two cases showed tending to be homogeneous enhancement. Six cases showed areas of low density without enhancement, and 9 cases were accompanied with single or multi-satellite punctuate or striped foci around the tumors.

CONCLUSIONDynamic contrast-enhanced CT and MRI combined with MR T2WI fat-suppression are of great importance in the diagnosis and identification of retroperitoneal localized Castleman's disease.

Adult ; Castleman Disease ; diagnostic imaging ; pathology ; surgery ; Female ; Humans ; Image Enhancement ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Radiographic Image Enhancement ; Retroperitoneal Space ; diagnostic imaging ; Retrospective Studies ; Tomography, X-Ray Computed

Objective To evaluate 3D printing abdominal aortic aneurysm model in analysis of clinical teaching effect for standardized resident doctors in vascular surgery department. Methods 48 resi-dents in vascular surgery department in our hospital from December 2016 to September 2017 were seleeected and randomly divided into control group and the experimental group. The traditional vascular surgical anatomy atlas, ultrasound, CT abdominal blood vessel 3D reconstruction, digital subtraction, video and so on were used by 24 residents in the control group, while in the experimental group, on the basis of the traditional teaching, abdominal aortic aneurysm model of 3D printing, true aortic coated stent delivery system were increased. After the teaching, the theory of evaluation (abdominal vascular anatomical features, morphological characteristics and classification of AAA, measurement of various parameters and key points of operation in the EVAR) and satisfaction questionnaire were adopted to evaluate the effect of two kinds of teaching methods. SPSS 19.0 was used to conduct t test on two groups of physician evaluation data. Results The results of theoretical assessment showed that there was no significant difference between the control group and the experimental group in the abdominal vascular anatomical features, the morphological features and the classification of the experimental group (P>0.05) in the examination of the common AAA cases and the complicated AAA cases. However, the experimental group was higher than the control group in the mea-surement of the parameters of EVAR, and the score of the operation points and the total score, and the difference was statistically significant (t=2.283, t=2.263, P<0.05). The results of the questionnaire showed that the students' satisfaction scores on the teaching satisfaction of the normal and complex AAA cases were better than those of the control group, and the difference was statistically significant (P<0.05). Conclusion The 3D printing model can increase the understanding and mastery of the anatomy and treat-ment of abdominal aortic aneurysm and improve its learning enthusiasm for vascular surgery. We should make full use of the advantages of 3D printing technology on the basis of retaining the advantages of tradi-tional teaching methods and means, and further enhance the teaching effect.

Renal collecting duct carcinoma(CDC) is rare in clinic, complicated with clear cell renal cell carcinoma(ccRCC) of one kidney is extremely rare. We reported a case CDC complicated with ccRCC of one kidney. The patient was admitted as left low back pain and gross hematuria, preoperative CT examination showed that one tumor was found in the upper middle pole and another tumor at lower pole of the left kidney, and multiple enlarged lymph nodes in the medial edge of the kidney. CT diagnosis was renal collecting duct carcinoma complicated with clear cell carcinoma of the left kidney, retroperitoneal lymphatic metastasis and underwent radical nephrectomy. Postoperative pathological diagnosis was CDC(upper middle pole) complicated with ccRCC(lower pole)of the left kidney. The patients were treated with sunitinib for 6 months and survived 13 months, and died of extensive metastasis.

Background Dengue fever is a mosquito-borne disease transmitted by Aedes aegypti and Aedes albopictus. Under the background of climate change, there are great challenges in the prevention and control of dengue fever, posing a serious health risk to the population. Objective To analyze the mechanism of temperature on dengue fever transmission and estimate the risk of dengue fever under different climate change scenarios by establishing a coupled human-mosquito dynamics model using Guangzhou as a research site, and to provide reference for adaptation to climate change. Methods Reported dengue fever cases and meteorological data from January 1, 2015 to December 31, 2019 in Guangzhou were collected from Guangdong Provincial Center for Disease Control and Prevention and China Meteorological Data Service Centre, respectively. The temperature data under three Representative Concentration Pahtyway (RCP2.6, RCP4.5, and RCP8.5) scenarios in 2030s (2031–2040), 2060s (2061–2070), and 2090s (2091–2099) were calculated by five general circulation models (GCMs) provided by the fifth phase of the Coupled Model Intercomparison Project. A dengue fever transmission dynamics (ELPSEI-SEIR) model was constructed to analyze the mechanism of temperature affecting dengue fever transmission by fitting the dengue fever epidemic trend from 2015–2019, and then the daily mean temperature under selected RCP scenarios for 2030s, 2060s, and 2090s was incorporated into the established dynamics model to predict the risk of dengue fever under different climate change scenarios in the future. Results From January 1, 2015 to December 31, 2019, a total of 4 234 cases of dengue fever were reported in Guangzhou, including 3741 local cases and 493 imported cases. The regression results showed that the model well fitted the dengue fever cases in Guangzhou from 2015 to 2019, and the coefficient of determination R2 to evaluate goodness of fit and the root mean squared error were 0.82 and 1.96, respectively. A U-shaped or inverted U-shaped relationship between temperature and mosquito habits could directly affect the number of mosquitoes and the transmission of dengue fever. We also found that temperature increase in most future scenarios could promote the transmission of dengue fever, and the epidemic period was significantly wider than the baseline stage. The epidemic of dengue fever would peak in the 2060s under the scenarios of RCP2.6 and RCP4.5. The estimated incidence of dengue fever was predicated to be highest in the 2030s and then decrease in the following years under RCP8.5, and in the 2090s, the incidence would decrease significantly, but the incidence peak would be earlier in each year, mainly from May to July. Conclusion Temperature can directly affect mosquito population and dengue fever transmission by affecting mosquito habits. The cases of dengue fever will increase under most climate scenarios in the future. However, the epidemic risk of dengue fever may be suppressed, and the epidemic season may be advanced under RCP8.5.