Microimaging evidences of hippocampal injury in radiotherapy avoiding hippocampus and its effects on cognition / 中华放射学杂志

Objective:To clarify the evidences of hippocampal injury after radiotherapy avoiding hippocampus and explore its relationships with cognition.Methods:A prospective design was adopted in this study.A total of 183 patients with nasopharyngeal carcinoma treated by intensity modulated radiation therapy (IMRT group) and 30 matched healthy control (HC group)were collected in the Affiliated Hospital of Jiangsu University and Southeast University Affiliated Zhongda Hospital from January 2017 to December 2019. All subjects were assessed by Montreal Cognitive Assessment (MoCA-B) at baseline and 6 months after radiotherapy, then the patients with nasopharyngeal carcinoma were divided into cognitive impairment group and non-cognitive impairment group. Subjects were scanned with Siemens 3.0 T MR, and T 1WI was used as analysis sequence.The individual standardized hippocampus ROIs were extracted based on Montreal Neurological Institute(MNI) brain template.All texture features were calculated using the Radiomics developed by C++and Delphi, and the intra group correlation coefficients (ICC), average direction, machine learning (random forest) and autocorrelation matrix were used for reducing the features dimension. One-way ANOVA and generalized linear models were used to compare the differences among different groups. Pearson correlations analyses were used to evaluate the relationships between important texture features and clinical data. Logistic regressions were used to calculate the abilities of texture features to predict cognitive impairment. Results:After 9 patients who lost follow-up were excluded, a total of 164 patients with nasopharyngeal carcinoma were included as IMRT group.Texture features of ROIs were extracted and dimensionally reduced successfully. Five differences features (Variance, Entropy, GlevNonU, RLNonUni and Contrast)were found among HC group, cognitive impairment group and non-cognitive impairment group, and the last three further showed significant differences within IMRT group (GlevNonU, P=0.011;RLNonUni, P<0.001;Contrast, P<0.001). Hippocampal doses were positively correlated with Variance ( r=0.448, P<0.05), and negatively correlated with Entropy ( r=-0.461, P<0.05). There was a positive correlation between MoCA-B scores with GlevNonU, RLNonUniand Contrast ( r=0.503, P<0.05; r=0.587, P<0.05; r=0.531, P<0.05). GlevNonU and Contrast were independent predictors of cognitive impairment in hippocampal avoidance of radiotherapy (OR=0.731, 95%CI 0.610-0.857; OR=0.651, 95%CI 0.496-0.853). Conclusion:Results of texture analysis could be used as micro imaging evidences of hippocampal injury in radiotherapy avoiding hippocampus, and could also effectively predict the occurrences of cognitive impairment.

Application of organ-system-based curriculum design in the training of post competency for medical imaging / 中华医学教育探索杂志

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.

Quantification of Fat Concentration and Vascular Response in Brown and White Adipose Tissue of Rats by Spectral CT Imaging

Comparison of different contrast agent concentrations in CT portal venography / 中华放射学杂志

Objective:To explore the effect of different contrast agent concentrations in CT portal venography and improve the success rate of examination.Methods:A total of 103 patients who underwent abdominal contrast-enhanced CT scan in Zhongda Hospital Southeast University from February to June 2019 were retrospectively analyzed. These patients were divided into two groups based on different contrast agent concentrations. Among them, 51 received high-concentration contrast agent (400 mg/ml) and 52 received low-concentration contrast agent (320 mg/ml). The data of portal vein phase were employed for portal venograpy reformation, and the CT values of the main portal vein, superior mesenteric vein, splenic vein, and portal vein enhanced were measured. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated to evaluate image quality objectively. Subjective assessment of image quality of CT images was performed by two experienced radiologists. Combining objective and subjective evaluations gave the overall evaluation of the image quality, implying whether different contrast agent concentrations would produce inconsistent image quality in portal venoraphy. Mann-Whitney U test and t test were used. Results:The image scores of the high and low concentration groups were 4.00 (3.97, 4.22) and 4.00 (3.40, 4.02), respectively. The difference was statistically significant ( Z=-2.329, P=0.020). The CT values of the portal vein, superior mesenteric vein, and portal vein enhanced in the high concentration group were higher than those in the low concentration group ( P< 0.05). However, no significant difference in CT value of spine vein, SNR nor CNR of the portal vein was detected between the two groups ( P>0.05). Conclusion:Using the same scanning technique and contrast injection protocol, portal venography examination with high contrast agent concentration can effectively improve the success rate and image quality.

Quantification of Organ Fat Deposits in Patients with Type 2 Diabetes Mellitus by Magnetic Resonance Imaging / 中国医学影像学杂志

Purpose Lipotoxicity plays an important role in the progression of diabetes and its complications,and the gold standards for organs' lipid quantification are biopsy or histochemical staining,which are invasive and have their own limitations.Thus,our research was to identify the difference in organ lipid deposition between type 2 diabetic patients and healthy volunteers by using noninvasive three-point T2* corrected Dixon imaging.Materials and Methods Sixty-five type 2 diabetic patients and 34 healthy volunteers were included in this study.All participants underwent three-echo Dixon with 3.0T MR imager.Dixon imaging parameters [hepatic fat fraction (HFF),splenic fat fraction (SFF),pancreatic fat fraction (PFF)] were collected.All of the MRI parameters were compared.The relationship between HFF,SFF,PFF and BMI,age were analyzed.Results The hepatic and splenic lipid percentage in diabetic group [HFF=(5.4±4.3)％;SFF=(3.7± 1.4)％] was significantly higher than healthy volunteers group [HFF=(2.9± 1.3)％;SFF=(3.0± 0.9)％;P＜0.05,respectively].However,there was no significant difference in pancreatic fat fraction between diabetic and healthy groups (P＞0.05).There were positive correlations between HFF,SFF,PFF and BMI (r=0.379,0.305 and 0.306,P＜0.05).Moreover,only the positive correlation between pancreatic fat fraction and age were observed (r=0.261,P＜0.05).Conclusion The three-point T2* corrected Dixon revealed the abnormalities of hepar and spleen lipid accumulation in diabetic patients.Thus,the three-point Dixon imaging may potentially aid in evaluating the lipid deposition of abdominal organs.

The use of multi-slice spiral CT angiography for hemoptysis / 中华放射学杂志

Objective To evaluate the nse of CT angiography in the diagnosis of hemoptysis and guiding the treatment of it with 64-slice spiral CT.Methods Twenty-two patients with repeated and massive hemoptysis underwent chest CT angiography.Results The blood supply of hemoptysis was nonbronchial systemic arteries in 3 patients,single or multiple bronchial arteries in 15 patients,mixed arteries of nonbronchial systemic and bronchial arteries in 3 patients and abnormal systemic arteries in 1 patient.Conclusion With 64-slice spiral CT,CT angiography provided useful information for the treatment of hemoptysis by guiding bronchial arterial embolization.

Noninvasive observation of atherosclerosis in mice with 7.0T MR and Micro-PET / 中国医学影像技术

Objective To explore the feasibility of detecting atherosclerosis with 7.0T MR and Micro-PET. Methods Ten 46-week-old ApoE-/- mice with high lipid diet for 6 months were selected to establish atherosclerosis models. Among them, 5 mice underwent MRI before and 12 h, 24 h, 36 h after injection of SPIO, respectively, and the other 5 mice were injected with ~(18)F-fluorodeoxyglucose (~(18)F-FDG) through tail vein and observed with Micro-PET after 1 h, 2 h and 3 h. The specimens of abdominal aorta were taken for pathologic examination. Results Atherosclerotic plaques were observed in all animals with 7.0T MRI after 6 months high lipid diet. Thirty-six hours after the injection of SPIO, the high signal rings were thinner and the lumen of blood vessels were wider than those before injection on T2WI. Radioactive concentration was observed in abdominal aorta and both sides of iliac artery 3 h after the injection of ~(18)F-fluorodeoxyglucose (~(18)F-FDG). Pathological examination showed the formation of atherosclerotic plaques and the aggregation of the macrophages. Conclusion 7.0T MRI and Micro-PET can be used to observe the macrophage-rich plaque and to judge the vulnerability of plaque, thus provide theoretical basis for early detection, diagnosis and treatment of atherosclerosis.

Quantification of fat using chemical shift imaging and 1H-MR spectroscopy in phantom model / 中华放射学杂志

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.

Monitoring intrahepatic hepatocellular carcinoma growth by 23Na-MRI and 1H-diffusion weighted imaging / 中华放射学杂志

Objective To monitor the structural and metabolic transformation of growing intrahepatic hepatocellular carcinoma (HCC) by non-invasive 23Na-MRI and 1H-DWI. Methods Each animal was examined weekly for4 weeks after injection of 1 × 106 N1S1 cells into the left liver lobe. MR images were acquired with a Varian MR system. The effects of untreated growth on water apparent diffusion coefficient (ADC), total tissue Na+ and intracellular Na+ were monitored in rat HCCs using 1H-DWI,single-quantum ( SQ ) 23 Na and triple-quantum-filtered (TQF) 23 Na-MRI. Histological analysis of HCC tissues was performed. Relative extracellular space (ECS), cell numbers, and the cell to nucleus area ratio were calculated. Statistical analysis of the data was performed by ANOVA and post-hoc multiple comparison.Results The doubling time of the tumor growth was 3.9 days. During the four weeks in tumor growing, the ratio of water ADC to nearby liver was always 1.4 to 1.5. The HCC growth was associated with an increase in both total tissue and intracellular 23Na signal intensity, and the changes in Nai+ were more profound than in Nat+. The ratio of the tumor SQ, TQF 23Na signal intensity to the nearby liver at four time points(7,14,21 and28 d) was 1.05 ±0.20,1.41 ±0.32,1.50±0.45,1.62±0.50(F=2.97,P＜0.05);1.32±0.11,1.54 ± 0.18,2.38 ± 0.22,2.39 ± 0.16 ( F = 11.18, P ＜ 0.01 ), respectively. Statistical analysis of the histological slices showed that the mean of relative ECS in healthy liver was significantly lower compared to both ECS spaces in HCC viable cells and inflammation/necrosis areas. The number of viable and inflamed/necrotic cells was statistically higher compared to nearby liver tissue. However, the increase in "cellularity" was caused mostly by shrinkage of cellular cytoplasm when the ratio of cell to nucleus areas decreased from 4.0 ± 0.3 ( normal liver) to 1.6 ± 0.1 ( viable HCC cells) ( t = 20.08,P ＜ 0.05). Conclusions The water ADC and SQ23 Na-MRI reflect ECS, total tissue Na+ changes and thus reflect mostly the compartmental alterations in tumor tissue, while TQF 23Na-MRI reflects the intracellular Na+ and thus physiological,metabolic transformation in HCC cells.

Construction and MRI of angiotensin Ⅱ transiently induced abdominal aortic dissection in ApoE-/-mouse model / 中国医学影像技术

Objective To establish abdominal aortic dissection model in ApoE-/-mice, and to evaluate the ability of 7.0T MR to detect the abdominal aortic artery aneurysms in ApoE-/-mice in vivo. Methods ApoE-/-mice aged 10 months were infused with angiotensin Ⅱ with 14 days Osmotic minipump after 10 weeks of high lipid diet. Two different doses of angiotensin Ⅱ were given to mice, i.e. 1000 ng/(kg·min) and 500 ng/(kg·min), respectively. The contrast group was infused with saline water. The abdominal aortic artery was observed in vivo with MR before and within 14 days infusion. At last, the pathological changes of the abdominal artery were compared with MRI findings. Results After 6 or 7 days higher dose of angiotensin Ⅱ infusion, aortic dissection was seen. MR T2WI showed crescent-shaped high signal in the vessel wall of one side，the pathological study identified the hematoma between media and adventitia. Abdominal aortic dissection aneurysms were also found in the mice 13 or 14 days after lower dose of angiotensin Ⅱ infusion, which were consistent with pathological studies. Besides, the signal of the vessel wall was significantly higher in both T2WI and PDWI sequences. There was excellent agreement between MR and histopathology. 〖WTHZ〗 Conclusion Abdominal aortic dissection aneurysms model can be successfully established with different doses (1000 ng/(kg·min) and 500 ng/(kg·min)) of angiotensin Ⅱ infusion into ApoE-/-mice fed with high lipid diet. High-resolution MR is able to visualize the abdominal aortic dissection aneurysm formation in vivo.

Magnetic particle labeling of bone marrow-derived mononuclear cells and magnetic resonance imaging after autologous transplantation / 中国组织工程研究

BACKGROUND:Among many transplanted cells,adult autologous bone barrow-derived mononuclear cells have beenused in clinical practice because they are easy to be obtained,without immunological rejection and ethical disputationand other advantages.How to distinguish donor cells from receptors and observe the survival of donor cells following stem cell transplantation still trouble people.OBJECTIVE: superparamagnetic iron oxide (SPIO)particles-labeled bone marrow-derived mononuclear cells from minipigs were used to observe the feasibility of in vivo tracking with magnetic resonance imaging(MRI).DESIGN:A controlled observation experiment.SETTING:Institute of Cardiovascular Disease,Zhongda Hospital Affiliated to Southeast University.MATERIALS:This experiment was carried out in the Institute of Cardiovascular Disease,Zhongda Hospital Affiliated to Southeast University between April 2006 and August 2006.Healthy Chinese minipigs,aged 3 to 4 months,weighing from 20 to 30 kg,were provided by the Experimental Animal Center of Southeast University[SYXK(Su)2002-0012].METHODS: Autologous bone marrow-derived mononuclear cells of minipigs were isolated and cultured. Bone marrow-derived mononuclear cells in the suspension were traced with SPIO particles.Ferrum in the cells were shown by Prussian blue staining, and cell viability was evaluated by trypan blue exclusion method. Eleven minipigs used for preparation of model of myocardial infarction were divided into experimental group(n=9)and control group(n=2).By means of percutaneous left or right cervical artery or femoral artery puncturation, 1.5 to 2.0 mm balloon was used to occlude 1/3 left anterior descending branch,304 to 405 kPa,60 minutes later,ischemic preconditioning was conducted 3 tO 4 times before operation. When pig models of myocardial infarction were successful that was proved by surface electrocardiogram,bone marrow-derived mononuclear cells were percutaneously injected into coronary artery.Coronary arteriography was performed through femoral artery acupuncture at 24 hours after establishing infarction models.Suspension of bone marrow-derived mononuclear cells was perfused into coronary artery with OTW catheter.Then,the injector and OTW catheter for containing cells were rinsed with normal saline containing heparin and infused with the residual cells within 10 minutes.Non-labeled cells were perfused in 2 minipigs of control group by the same method.Postoperatively, bone marrow-derived mononuclear cells were traced by magnetic resonance and compared with Prussian blue-stained myocardial tissue sections.RESULTS: Seven minipigs of experimental group and one minipig of control group were Involved in the final analysis.One of each group was used for preparation of model of myocardial Infarction.One minipig of experimental group died from anesthetic accident before magnetic resonance.①Bone marrow-derived mononuclear cells all were nearly labeled by SPIO particles. Bone marrow-derived mononuclear cells could further proliferate in culture medium containing Fe2O3-PLL without obvious changes of cellular shape. ②T2+WI showed that 5 of 8 models of myocardial infarction presented fuzzy low-echo signal region in peripheral myocardial infarction after transplantation of labeled cells and the low-echo signal disappeared 4 weeks Iater. Ex vivo T2+WI sequence showed there was a dot-distributed low-echo signal region in the peripheral infarction region.③It was found in histological examination that 5 models(cell number over 106) had Prussian blue-positive cells,which distributed the same as those in magnetic resonance signal reducing region.CONCLUSION:SPIO particles-labeled bone marrow-derived mononuclear cells are safe and effective;T2+ WI is sensitive to tracing SPIO particles-labeled bone marrow-derived mononuclear cells;Magnetic resonance can in vivo trace SPIO particles-labeled stem cells transplanted through coronary artery,magnetic resonance signal change is related with the number of stem cells and division growth.

Experiment research of autoradiogam by ~(99)Tc~m-TRODAT-1 in Parkinson disease models rat / 医学研究生学报

Objective: To develop ~(99)Tc~m labeled dopamine transporter(DAT) imaging agent ~(99)Tc~m-(2?-[N,N~(,)-bis(2-mercaptoethyl)ethylenediamino]methyl,3?-(4-chlorophenyl)tropane(TRODAT-1) for evaluating changes of DAT in patients with Parkinson disease(PD). Methods: The SD rats were divided into control group(n=5),PD models group(n=22)and generalized cerebral infarction models group(n=5).~() Unilateral smashing and injecting autothrombo into carotid artery of SD rats were used.~(99)Tc~m-TRODAT-1 distributing in normal rat striatum was observed.The uptakes in sound side and smashed side of PD rats striatum and in two sides of multiple infarction rats striatum were compared. Results:~(99)Tc~m-TRODAT-1 distribution in normal rats striatum exhibited a obvious uptake in striatum.And PD rats results exhibited that the uptake was less in normal striatum than in smashed striatum obviously.The result of multiple infarction rats is same as normals rats. Conclusion: ~(99)Tc~m-TRODAT-1 might betaked specificly.Its imaging can provide a beneficial evidence for PD disease early diagnose.

Prognostic Reevaluation of CT and Clinical Criteria for Acute Pancreatitis / 实用放射学杂志

Objective To reassess the value of CT and clinical criteria as prognostic and severity indicators in acute pancreatitis and to investigate the correlation between them.Methods Of 65 cases of acute pancreatitis,the hospitalization days,fevering days and entire complications (including local and systemic complications)were regarded as clinical endpoints.CT criteria included Balthazar's plain CT scan score,necrosis score,CT severity index(CTSI) and London's PSI score.Clinical criteria included Ranson and APACHE Ⅱscore.Using analysis of variance,t-test and multiple linear regression analysis,the correlation between each criteria and the three clinical endpoints was examined as well as the relation between CT and clinical criteria.The power of each criteria and combination of CT and clinical criteria in predicting entire complications of AP was assessed and compared by using ROC analysis.Results The mean scores of PSI,Ranson and APACHE Ⅱamong three groups classified according to entire complications were significantly different.Except Balthazar's plain CT scan criteria,each criteria's mean scores in group with local complications was signifiantly higher than that in group without and entire complications was significantly more in sever group than that in mild group.Mean hospitalization days and fevering days were significantly longer in sever group than that in mild group with Ranson Score.PSI and Ranson score had linear correlation with fevering days,and Ranson score had linear correlation with hospitalization days.In CT criteria,a linear correlation was only found between PSI and Ranson score.ROC analysis showed the Az of Ranson score was the largest,and there was no increase in the Az when CT criteria were added to clinical criteria.Conclusion The predictive value of Ranson score and PSI are superior to that of others.Clinical criteria is superior in predicting systemic complications,whereas CT is superior in predicting local complications.There is no improvement in predicting entire complications of AP when CT criteria are added to clinical criteria.The findings of plain CT scan is found to be some laggard compared with that of clinic.CT scan and short follow-up are important in the evaluation of AP.

Evaluation of gastric carcinoma with CT three-dimensional imaging compared with conventional barium study / 中华放射学杂志

0.05), but the lesion detection sensitivity of SSD and Raysum display were lower than that of UGI(? 2=4.17,7.11, and 5.14,4.17, P0.05). Excess fluid remained in the stomach and patient respiratory movement during breath holds were the reasons causing severe artifacts (6.1%) that influenced the diagnostic evaluation. Conclusion The performance of CTVG was equivalent to UGI in the detection of advanced gastric carcinoma and superior to UGI in the Borrmann′s classification. CTVG has potential in the detection of early gastric carcinoma. The value of SSD and Raysum display was limited in the evaluation of gastric carcinoma when used alone clinically.

Magnetic resonance imaging tracking of SPIO-labeled embryonic neural stem cells transplantation into corpus striatum of the focal cerebral ischemia rats and the effects of learning and memory abilities / 临床神经病学杂志

Objective To explore the magnetic resonance imging tracking of superparamagnetic iron oxid(SPIO) labeled embryonic neural stem cells (NSCs) transplantation into corpus striatum of the focal cerebral ischemia(FCI) rats and the effects of learning and memory abilities.Methods NSCs of embryonic rat were cultured in vitro and labeled with Fe2O3-mediated by poly-L lysine (PLL), with Prussian blue staining to evaluate the labeling rate and Trypan blue staining to observe cell viability of NSCs. The rats were randomly divided into groups A (normal control),B (normal labeled NSCs implanted),C (cerebral ischemia),D( labeled NSCs implanted),E (unlabeled NSCs implanted)and F (inactivated labeled NSCs implanted).The FCI models were made in groups C, D, E, F.The labeled NSCs or unlabeled NSCs or inactivated labeled NSCs were stereotaxically injected into the left corpus striatum of groups B,D,E,F respectively. The abilities of learning and memory were measured by the Y-type electronical maze in groups A, C, D, E after 3 d,7 d,2,3,4 weeks of transplantation respectively. MRI scanning was performed to monitor the NSCs in groups B, D, F at corresponding time. After MRI, the rats were killed and undergone Prussian blue staining of the brain histological section to observe the distribution of implanted NSCs.Results The labeling efficiency rate and cell viability of Fe2O3-PLL labeled NSCs were almost 100% and 95% respectively. Compared with group C, the abilities of learning and memory were significantly improved at each time point after transplantation in groups D, E (all P