Cycle-Consistent Generative Adversarial Network: Effect on Radiation Dose Reduction and Image Quality Improvement in Ultralow-Dose CT for Evaluation of Pulmonary Tuberculosis

Objective@#To investigate the image quality of ultralow-dose CT (ULDCT) of the chest reconstructed using a cycle-consistent generative adversarial network (CycleGAN)-based deep learning method in the evaluation of pulmonary tuberculosis. @*Materials and Methods@#Between June 2019 and November 2019, 103 patients (mean age, 40.8 ± 13.6 years; 61 men and 42 women) with pulmonary tuberculosis were prospectively enrolled to undergo standard-dose CT (120 kVp with automated exposure control), followed immediately by ULDCT (80 kVp and 10 mAs). The images of the two successive scans were used to train the CycleGAN framework for image-to-image translation. The denoising efficacy of the CycleGAN algorithm was compared with that of hybrid and model-based iterative reconstruction. Repeated-measures analysis of variance and Wilcoxon signedrank test were performed to compare the objective measurements and the subjective image quality scores, respectively. @*Results@#With the optimized CycleGAN denoising model, using the ULDCT images as input, the peak signal-to-noise ratio and structural similarity index improved by 2.0 dB and 0.21, respectively. The CycleGAN-generated denoised ULDCT images typically provided satisfactory image quality for optimal visibility of anatomic structures and pathological findings, with a lower level of image noise (mean ± standard deviation [SD], 19.5 ± 3.0 Hounsfield unit [HU]) than that of the hybrid (66.3 ± 10.5 HU, p 0.908). The CycleGAN-generated images showed the highest contrast-to-noise ratios for the pulmonary lesions, followed by the model-based and hybrid iterative reconstruction. The mean effective radiation dose of ULDCT was 0.12 mSv with a mean 93.9% reduction compared to standard-dose CT. @*Conclusion@#The optimized CycleGAN technique may allow the synthesis of diagnostically acceptable images from ULDCT of the chest for the evaluation of pulmonary tuberculosis.

Cycle-Consistent Generative Adversarial Network: Effect on Radiation Dose Reduction and Image Quality Improvement in Ultralow-Dose CT for Evaluation of Pulmonary Tuberculosis

Objective@#To investigate the image quality of ultralow-dose CT (ULDCT) of the chest reconstructed using a cycle-consistent generative adversarial network (CycleGAN)-based deep learning method in the evaluation of pulmonary tuberculosis. @*Materials and Methods@#Between June 2019 and November 2019, 103 patients (mean age, 40.8 ± 13.6 years; 61 men and 42 women) with pulmonary tuberculosis were prospectively enrolled to undergo standard-dose CT (120 kVp with automated exposure control), followed immediately by ULDCT (80 kVp and 10 mAs). The images of the two successive scans were used to train the CycleGAN framework for image-to-image translation. The denoising efficacy of the CycleGAN algorithm was compared with that of hybrid and model-based iterative reconstruction. Repeated-measures analysis of variance and Wilcoxon signedrank test were performed to compare the objective measurements and the subjective image quality scores, respectively. @*Results@#With the optimized CycleGAN denoising model, using the ULDCT images as input, the peak signal-to-noise ratio and structural similarity index improved by 2.0 dB and 0.21, respectively. The CycleGAN-generated denoised ULDCT images typically provided satisfactory image quality for optimal visibility of anatomic structures and pathological findings, with a lower level of image noise (mean ± standard deviation [SD], 19.5 ± 3.0 Hounsfield unit [HU]) than that of the hybrid (66.3 ± 10.5 HU, p 0.908). The CycleGAN-generated images showed the highest contrast-to-noise ratios for the pulmonary lesions, followed by the model-based and hybrid iterative reconstruction. The mean effective radiation dose of ULDCT was 0.12 mSv with a mean 93.9% reduction compared to standard-dose CT. @*Conclusion@#The optimized CycleGAN technique may allow the synthesis of diagnostically acceptable images from ULDCT of the chest for the evaluation of pulmonary tuberculosis.

Inflow-based vascular-space-occupancy MRI for evaluation of arteriolar muscular blood volume in dermatomyositis patients / 中华放射学杂志

Objective:To investigate the reproducibility of inflow-based vascular-space-occupancy (iVASO)-MRI in quantifying skeletal muscle perfusion and its potential clinical value in patients with dermatomyositis (DM).Methods:Totally 15 consecutive patients with DM and 15 healthy volunteers were enrolled in this prospective study from December 2018 to April 2019 at Nanfang Hospital, Southern Medical University. All subjects underwent T 1WI, short-tau inversion recovery (STIR) T 2WI, and iVASO-MRI of thigh on a 3.0 T MR scanner. According to findings on T 1WI and STIR T 2WI, the muscles were divided into normal, unaffected, edematous and atrophic or fat-infiltrated groups. Maximum arteriolar muscular blood volume (MBVa_max) and mean MBVa (MBVa_mean) of these 4 groups of muscles were obtained by 2 radiologists independently. In order to evaluate the reproducibility of iVASO, the repeated scan was performed 3 days later in 17 subjects (12 healthy volunteers and 5 DM patients), and the MBVa values were measured to calculate the intraclass correlation coefficients (ICC). The MBVa_max and MBVa_mean among the 4 groups were compared by using Kruskal-Wallis H test and the differences of each 2 groups was compare by using Mann-Whitney U test. Results:The ICC between the 2 observers was 0.95 and 0.96 for MBVa_max and MBVa_mean, respectively. The ICC between repeated tests was 0.87 and 0.89 for MBVa_max and MBVa_mean, respectively.There was significant difference among normal muscles, unaffected muscles, edematous muscles and atrophic or fat-infiltrated muscles ( P<0.001). Post hoc comparisons of MBVa_max and MBVa_mean showed that compared to normal muscles, unaffected muscles, edematous muscles and atrophic or fat-infiltrated muscles had a significant decrease of MBVa ( P<0.05). Unaffected muscles and edematous muscles showed no significant difference in terms of MBVa_max and MBVa_mean (both P=0.99), which were significantly higher than those of atrophic or fat-infiltrated muscles ( P<0.05). Conclusions:iVASO-MRIcan reliably quantify the MBVa of thigh muscular arteriolar, and it is potentially valuable in the diagnosis of DM.

Experience of COVID-19 prevention and control in shelter CT / 中国医学物理学杂志

Since the outbreak of coronavirus disease 2019 (COVID-19), chest computed tomography (CT) has been an important imaging modality in the diagnosis, treatment and follow-up of patients with COVID-19,but meanwhile the risk of cross-infection between the staff and patients in Department of Radiology is increasing. Shelter CT is specifically used for the examination of patients with suspected or confirmed COVID-19 to reduce the infection risk. Based on practical work experience, the management and prevention measures for COVID-19 in shelter CT are discussed from the aspects of the installation, function division and examination procedures of shelter CT, patient examination route, the staff management and infection prevention for radiology technologists, and the disinfection of CT equipments and object surface.

Gadoxetic acid enhanced T1ρ and intravoxel incoherent motion MRI in quantitatively assessing the stages of nonalcoholic steatohepatitis / 中华放射学杂志

Objective@#To explore the values of metrics on intravoxel incoherent motion (IVIM) and gadoxetic acid enhanced T1ρ imaging for staging of non-alcoholic fatty liver disease activity scores (NAS) and inflammation in nonalcoholic steatohepatitis (NASH) rabbits model.@*Methods@#NASH rabbits model was established by feeding with a varied duration (4, 8, 12 weeks) of high-fat, high-cholesterol diet. IVIM and gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) enhanced T1ρ images were performed by a 3.0 T MR scanner. The inter-class correlation coefficients (ICC) and Bland-Altman analysis were applied to evaluate the reproducibility of the IVIM and Gd-EOB-DTPA enhanced T1ρ mapping measurers. Spearman correlation analysis were used to assess the correlation between MR metrics, including ADC, D, D*, f, T1ρ, T1ρ (hepatobiliary phase, HBP), and NAS score and inflammation grades respectively with reference to histopathology. ROC curve analysis was used to evaluate the diagnostic performance of T1ρ and IVIM parameters for NASH, inflammation grade, and hepatic fibrosis. Multiple linear regression equations were used to analyze the independent influence factors of T1ρ (HBP).@*Results@#The f value was negatively correlated with the NAS score (r=-0.530, P<0.01). The f value of the fibrosis S1-2 was significantly lower than that of the S0 (P<0.01). There was no statistical difference in D, D*, ADC among NASH score, inflammation, and fibrosis stage. T1ρ and T1ρ (HBP) values were positively correlated with NAS scores and inflammation grades. The area under curve (AUC) for the diagnosis of NASH for T1ρ, T1ρ(HBP), ADC, D, D*, and f values were 0.849, 0.949, 0.728, 0.596, 0.522, and 0.871, respectively. The AUCs of T1ρ (HBP)+f in the diagnosis of NASH, G2-3 inflammation, and F1-2 fibrosis were 0.971, 0.935, and 0.903, respectively. Fibrosis (R2=0.624, P=0.002) and inflammation (R2=0.746, P=0.002) were major independent factors of T1ρ (HBP).@*Conclusion@#Gd-EOB-DTPA enhanced T1ρ imaging can reflect the severity of NASH and degree of inflammation. IVIM measurements are not accurate enough to stage liver inflammatory activity of NASH. T1ρ (HBP)+f might be a superior noninvasive imaging biomarker than either non-enhanced T1ρ or IVIM for NASH activity and inflammation assessments.

Gadoxetic acid enhanced T1ρ and intravoxel incoherent motion MRI in quantitatively assessing the stages of nonalcoholic steatohepatitis / 中华放射学杂志

Objective To explore the values of metrics on intravoxel incoherent motion (IVIM) and gadoxetic acid enhanced T1ρ imaging for staging of non?alcoholic fatty liver disease activity scores (NAS) and inflammation in nonalcoholic steatohepatitis (NASH) rabbits model. Methods NASH rabbits model was established by feeding with a varied duration (4, 8, 12 weeks) of high?fat, high?cholesterol diet. IVIM and gadolinium?ethoxybenzyl?diethylenetriamine pentaacetic acid (Gd?EOB?DTPA) enhanced T1ρ images were performed by a 3.0 T MR scanner. The inter?class correlation coefficients (ICC) and Bland?Altman analysis were applied to evaluate the reproducibility of the IVIM and Gd?EOB?DTPA enhanced T1ρ mapping measurers. Spearman correlation analysis were used to assess the correlation between MR metrics, including ADC, D, D*, f, T1ρ, T1ρ (hepatobiliary phase, HBP), and NAS score and inflammation grades respectively with reference to histopathology. ROC curve analysis was used to evaluate the diagnostic performance of T1ρ and IVIM parameters for NASH, inflammation grade, and hepatic fibrosis. Multiple linear regression equations were used to analyze the independent influence factors of T1ρ (HBP). Results The f value was negatively correlated with the NAS score (r=-0.530, P<0.01). The f value of the fibrosis S1?2 was significantly lower than that of the S0 (P<0.01). There was no statistical difference in D, D*, ADC among NASH score, inflammation, and fibrosis stage. T1ρ and T1ρ (HBP) values were positively correlated with NAS scores and inflammation grades. The area under curve (AUC) for the diagnosis of NASH for T1ρ, T1ρ(HBP), ADC, D, D*, and f values were 0.849, 0.949, 0.728, 0.596, 0.522, and 0.871, respectively. The AUCs of T1ρ (HBP)+f in the diagnosis of NASH, G2?3 inflammation, and F1?2 fibrosis were 0.971, 0.935, and 0.903, respectively. Fibrosis (R2=0.624, P=0.002) and inflammation (R2=0.746, P=0.002) were major independent factors of T1ρ (HBP). Conclusion Gd?EOB?DTPA enhanced T1ρ imaging can reflect the severity of NASH and degree of inflammation. IVIM measurements are not accurate enough to stage liver inflammatory activity of NASH. T1ρ (HBP)+f might be a superior noninvasive imaging biomarker than either non?enhanced T1ρ or IVIM for NASH activity and inflammation assessments.

Evaluation of renal oxygenation in rats with acute aristolochic acid nephropathy using blood oxygenation level-dependent magnetic resonance imaging / 南方医科大学学报

OBJECTIVE@#To evaluate the changes in renal oxygenation in rats with acute aristolochic acid nephropathy using blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) at 7.0T.@*METHODS@#Wistar rats were randomly divided into AAN group (=18) and control group (=6) for intraperitoneal injections of AAI at 40 mg/kg and PEG400, respectively, on a daily basis for 6 consecutive days. All the control rats and 6 rats from AAN group underwent BOLD MRI scan before and at 2, 4, and 6 days after the initial injection for measuring renal cortical and medullary R2 values. At each of the 4 time points, 3 rats in AAN group were sacrificed for histological evaluation; the control rats were examined at 6 days after the initial injection.@*RESULTS@#The cortical and medullary R2 values of the rats in AAN group on days 4 and 6 were significantly higher than those in the control group ( < 0.05). In AAN group, the cortical R2 values showed no obvious changes on day 2 as compared with the baseline values, but increased significantly on day 4 ( < 0.05) and day 6 ( < 0.01); the medullary R2 values increased progressively and were significantly higher than the baseline values on day 4 ( < 0.01) and day 6 ( < 0.01). In the control group, no significant changes were detected in either cortical or medullary R2 values throughout the experiment.@*CONCLUSIONS@#BOLD MRI allows non-invasive measurement of renal oxygenation levels in rats with AAN. The increase of renal cortical and medullary R2 values, and particularly the latter, indicates a lowered renal oxygenation level, which provides potentially useful information for clinical decisions.

MRI characteristic features for diagnosing central neurocytoma / 中国医学影像技术

Objective To investigate the diagnostic value of six MRI characteristic features for diagnosing central neurocytoma (CN).Methods MRI data of 30 cases of CN and 68 cases of non-CN located in lateral ventricles were retrospectively analyzed.Six characteristic MRI features,including scalloping sign,broad-based attachment sign,soapbubble sign,peripheral cyst sign,fluid-fluid level sign and gemstone sign were scored based on a five-point scale.ROC curve was used to assess the diagnostic value of each MRI sign.Results The scalloping sign showed the highest area under the curve (AUC) value (0.82) among all 6 signs (all P＜0.05),followed by broad-based attachment,soap-bubble andperipheral cyst signs (AUC 0.73-0.75),higher than that of fluid-fluid level sign and gemstone sign (all P＜0.05).The scalloping sign exhibited the highest specificity (84.56 ％),followed by fluid-fluid level (77.94 ％),gemstone (74.26 ％) and peripheral cyst (70.34％) sign.The soap-bubble sign (83.89％) was the most sensitive sign,followed by broad-based attachment sign (76.11％) and peripheral cyst sign (75.00％).Conclusion The scalloping sign is the most valuable indicator for CN among six characteristic MRI features.

Supratentorial primitive neutoectodermal tumors in adults:imaging findings and analysis on misdiagnosis / 实用放射学杂志

Objective To investigate the CT and MRI features of supratentorial primitive neuroectodermal tumors (sPNET)in adults,and to analyze the reasons of misdiagnosis.Methods The CT and MRI features of 1 5 patients with sPNET confirmed by pathology were analyzed retrospective.13 of 15 patients were underwent plain and contrast enhanced MRI,4 patients were also performed CT scan and the other 2 patients were underwent CT plain scan only.Results Nine of 1 5 lesions were located in the temporal and/or frontal lobe,with clear margin in 12 lesions,and mild to moderate peritumoral was noted in most cases.The solid portion of the lesions were hyperdense on CT,isointense or slightly hypointense on T1WI,and isointense or hyperintense on T2WI compared to the gray matter.Calcification (2/6),necrosis or cystic degeneration(1 3/1 5),hemorrhage (8/1 5)and flow void signal (1 1/1 3)were seen.Twelve lesions showed significantly heterogeneous enhancement and 7 lesions showed irregular ring-enhancement.The solid parts in 5 lesions showed hyperintensity on diffusion-weighted imaging. Preoperatively,the lesions were misdiagnosed as glioma in 10 cases,ependymoma in 2 cases,meningioma in 1 case and germ cell tumor in 1 case, respectively;and 1 case was not diagnosed definitely.Conclusion Supratentorial PNET in adults has characteristic CT and MRI features,and the main reasons accounting for misdiagnosis are its extraordinary low incidence and that radiologists do no master its imaging features.

Changes in regional homogeneity of brain activity in patients with diabetic peripheral / 南方医科大学学报

OBJECTIVE@#To investigate the abnormalities in regional homogeneity of brain activity in patients with diabetic peripheral neuropathy (DPN) using resting-state functional magnetic resonance imaging (rs-fMRI) and explore the association between brain activity changes and DPN.@*METHODS@#A regional homogeneity (ReHo) approach was used to compare the local synchronization of rs-fMRI signals among 20 patients with painful DPN, 16 patients with painless DPN, and 16 type 2 diabetic patients without DPN (non-DPN group).@*RESULTS@#Compared with the those without DPN, the patients with painful DPN showed high ReHo in the left inferior temporal gyrus and the right central posterior gyrus, and low ReHo in the posterior cingulate gyrus, right inferior parietal gyrus, and the left superior parietal gyrus ( < 0.05);the patients with painless DPN group showed high ReHo in the left inferior temporal gyrus, the right middle temporal gyrus, and the right superior frontal gyrus, and low ReHo in the left thalamus ( < 0.05).No significant differences in ReHo were found between the patients with painful DPN and painless DPN (>0.05).@*CONCLUSIONS@#The patients with DPN have altered ReHo in multiple brain regions and impairment of a default mode network, for which the left temporal gyrus may serve as a functional compensatory brain area. ReHo disturbance in the central right posterior gyrus may play a central role in the pain symptoms associated with painful DPN.

Comparative study of evaluating between the well-differentiated hepatocellular carcinoma and non well-dif-ferentiated HCC in Gd-EOB-DTPA multi-modality MRI / 实用医学杂志

Objective To investigate the differences in GD-EOB-DTPA multi-modality MR images be-tween well-differentiated hepatocellular carcinoma(WHCC)and non well-differentiated HCC.Methods The clin-ical and MR images of 57 patients with pathologically proved HCC were retrospectively collected. All patients un-derwent abdominal enhancement MRI,including T1 weighted and T2 weighted imaging(T1WI and T2WI),diffu-sion weighted imaging(DWI),the apparent diffusion coefficient(ADC)map,and gadoxetic acid-enhanced multi-phase sequences. The patients were classified into well-differentiated HCC(WHCC)group and non-WHCC group which combined moderate HCC and poor differentiated HCC according to their histopathological differentiation.Dif-ferences of T1WI,T2WI,DWI,ADC map,the types of HCC on hepatobiliary phase(HBP)images,and enhance-ment patterns on dynamic images were compared. The chi-square test or Fisher exact was used for comparing the imaging signal differences between WHCC and non-WHCC. Multiple logistic regression analysis was performed to identify the independent predictors of WHCC. Results T1WI signal intensities,HBP signal types,enhancement patterns and ADC maps showed statistical significance between WHCC and non-WHCC(P<0.05).But,multiple logistic regression analysis showed that signal intensities on T1WI were independent risk factors for WHCC(P =0.001). In addition,hyperintense on T1WI showed higher statistical significance compared with isointense or hy-pointense on T1WI(P = 0.002). Conclusions Multi-modality of GD-EOB-DTPA MRI is useful for assessing WHCC. The signal intensities on T1WI are independent risk factors for evaluating WHCC. Moreover,WHCC are more likely in hyperintense T1WI signal intensity.

Comparison of contrast enhanced MR angiography and CT angiography in displaying blood supply of early stage cervical cancer / 中国医学影像技术

Objective To compare the display effect of contrast enhanced MR angiography (CE-MRA) and CTA in evaluating blood supply of early stage cervical cancer.Methods CE-MRA and CTA before the operation of 30 patients with pathologically confirmed early stage cervical cancer were analyzed retrospectively.The origins and continuity of bilateral uterine arteries and the conspicuity of bilateral decending branch of uterine arteries between CE-MRA and CTA were evaluated.Results Fifty uterine arteries could classify as origins clearly visible and vessels clearly visible without discontinuity,5 uterine arteries as origins clearly visible but vessels unclearly visible on both CEMRA and CTA.Both CE-MRA and CTA were conformed well in evaluating the origin and continuity of uterine arteries (Kappa=0.80,P＜0.05).The conspicuity of decending branches for CE-MRA was 55.00％ (33/60),which was lower than that of CTA (73.33％ [44/60]),which had statistically significant difference between CE-MRA and CTA (x2 26.22,P＜0.01).Conclusion For early stage cervical cancer,CE-MRA and CTA can both provide a good performance in evaluating the origin and continuity of uterine arteries,CTA reveals advantage over CE MRA in detecting conspicuity of decending branch of uterine arteries.

Evaluation of intravoxel incoherent motion DWI in differential diagnosis of hepatocellular carcinoma and focal nodular hyperplasia / 中国医学影像技术

Objective To explore the feasibility of intravoxel incoherent motion DWI (IVIM-DWI) in differential diagnosis of hepatocellular carcinoma (HCC) and focal nodular hyperplasia (FNH).Methods A total of 407 patients with clinically-suspected HCC or FNH underwent conventional and dynamic enhanced MRI and IVIM-DWI,60 patients (40 cases of HCC,20 cases of FNH) were enrolled.Parameters of ADC,slow apparent diffusion coefficient (D),fast apparent diffusion coefficient (D*) and fraction of fast apparent diffusion coefficient (f) were obtained by monoexponential model and biexponential model respectively.Results The values of ADC,D,D* and f in FNH group were (1.60±-0.25) × 10-3mm2/s,(1.12±0.17)×10-3mm2/s,(44.89±18.23)× 10-3 mm2/s and (34.80 ± 9.68)％,and those in HCC group were (1.32 ± 0.21) × 10-3 mm2/s,(0.82±-0.21) × 10-3mm2/s,(49.82±20.11) × 10 3mm2/s and (28.72±13.84) ％,respectively.Significant inter-group differences were observed in ADC and D (both P＜0.001),however,there were no significant differences in D* and f (both P＞0.05).The areas under the ROC curve of D were 0.90,and taking D=0.96 × 10-3 mm2/s as cut-off value,the sensitivity and specificity of D in diagnosis of HCC were 84.44％ and 90.02％.Conclusion IVIM-DWI is useful to distinguish FNH from HCC,and the D value in biexponential model has the best diagnostic efficacy for differentiations.

Evaluation of transition zone prostate cancer by Logistic regression of prostate imaging reporting and data system version 2 combined with prostate specific antigen / 中国医学影像技术

Objective To establish the Logistic regression model by reporting and data system version 2 (PI-RADS v2)and prostate specific antigen (PSA),and to evaluate the diagnostic efficiency in transition zone prostate cancer (PCa).Methods MRI and PSA data of 33 patients with PCa and 54 patients with non-PCa confirmed by pathology were analyzed retrospectively.The PI-RADS v2 was used to evaluate the risk of 2 groups (from low to high as 1 to 5 points).Total PSA (t-PSA),free to total PSA ratio (f-PSA/t-PSA),PSA density (PSAD) and PI-RADS v2 scores were compared between 2 groups.The Logistic regression models were established with parameters which were significantly different between 2 groups.The Logistic regression was divide into three protocols:PI-RADS v2-+ t-PSA (A),PI-RADS v2 + f-PSA/t-PSA (B),PI-RADS v2+PSAD (C).The ROC curves were constructed by the new parameters Logit (P) and PI-RADS v2 scores for assessing the diagnostic efficiency.Results The t-PSA,f-PSA/t-PSA,PSAD and PI-RADS v2 scores had significant differences between the 2 groups (all P＜0.01).Predictive multivariate model of A,B,C was established as Logit (P)=-8.682+1.507 PI-RADS v2+0.234 t-PSA (x2=65.993,P＜0.01),Logit(P)=-5.425+1.906 PI-RADS v2 13.921 f-PSA/t-PSA (x2 =65.993,P＜0.01),Logit(P)=-7.534+1.045 PI-RADS v2+13.318 PSAD (x2 =74.036,P＜0.01),their area underthe curve (0.945,0.919,0.960) were all higher than that of PI-RADS v2 score (0.861,all P ＜0.01).The protocol C had the best diagnostic efficiency,and the sensitivity and specificity were 87.88 ％ and 92.59 ％.The sensitivity and specificity of PI-RADS v2 score were 87.88％ and 77.78％.Conclusion The diagnostic efficiency of the Logistic regression model which includes the PI-RADS v2 score and PSA are superior to the PI-RADS v2 score alone for transition zone PCa,which can provide a reliable basis for patients whether need biopsy or not.

MRI findings of adenomatoid tumor of epididymis / 实用放射学杂志

Objective To investigate the MRI manifestations and diagnostic value of adenomatoid tumor (AT)of epididymis. Methods The MRI features of 5 patients with AT of epididymis were analyzed retrospectively,which were confirmed by histopathology,and some relevant medical literatures were reviewed.Results The epididymal tumor was manifested as moderate signal on T1 WI and T2 WI,similar to adjacent testicule,and as moderate signal with slightly high rim-enhancement on enhanced T1 WI in 4 cases.Secondary infarction and chronic granulomatous inflammation in 1 patient was found and presented unevenly moderate signal on T1 WI,slight hypointensity on T2 WI, hyperintensity on DWI and rim-enhancement on dynamic enhancement MRI.Few hydrocele was detected in all 5 patients.Conclusion AT of epididymis is a rare benign neoplasm with some characteristic MRI features which is helpful for the preoperative diagnosis.

In vitro studies of glypican-3 targeting pretargeting technology for molecular MRI of hepatocellular carcinoma / 中华放射学杂志

Objective To explore the value of pretargeting technology in vitro MRI of L5 peptide guided streptavidin-conjugated and polyethylene glycol modification protected ultra-small superparamagnetic iron oxide(SA-PEG-USPIO) to hepatocellular carcinoma(HCC) via glypican-3(GPC3) receptor.Methods Direct immumofluorescence assay with carboxyfluorescein(FAM) labeled L5 and competitive inhibition was performed in HepG2 and HL-7702 cells.Imaging was obtained from fluorescent microscope.Immunoassay fluorescence images were carried out to determine the expression of GPC3 in HepG2 cell.PEG-USPIO conjugated with streptavidin was made by carbodiimide reaction,and the hydrodynamic diameters,Zeta potential and magnetic relaxivity of SA-PEG-USPIO and PEG-USPIO were measured.HL7702 cells were used for evaluate cells viability of SA-PEG-USPIO and PEG-USPIO.HepG2 and HL-7702 cells were used as experimental and control group respectively.Each of the two cell lines were further divided into three groups:L5-BT united SA-PEG-USPIO group,SA-PEG-USPIO group and control group.Prussian blue staining and MRI was preformed to observe the targeting efficacy of SA-PEG-USPIO respectively,and normalized T2 signal was recorded.The significant changes of normalized T2 signal intensity among groups was deterumine by using One-way analysis of variance.Results There were much more fluorescences on the membrane and cytoplasm of HepG2 cells than those on HL-7702 cells and cells of competition group.And indirect immunofluorescence images show the obvious expression of GPC3 in HepG2 cell.The SA-PEG-USPIO and PEG-USPIO nanoparticles had hydrodynamic diameters of (22.73 ± 3.31) and (35.97±5.19)nm,Zeta potential of them were (4.22±0.53) and (-7.91± 1.22)mV and magnetic relaxivity were 0.139 4× 103 and 0.103 9 × 103 mM-1s1.Although the highest concentration of SA-PEG-USPIO and PEG-USPIO was 2.4 mmol/L,cells viability was greater than 80％.The most iron particle was observed in L5-BT united SA-PEG-USPIO group of HepG2 cells.In vitro MR,the normalized T2 signal intensity of HepG2 cells in L5-BT united SA-PEG-USPIO group,SA-PEG-USPIO group and control group were 39±7,77 ± 12 and 93 ± 4.There was significant difference among those three groups (F=23.96,P＜0.01).The normalized T2 signal intensity of HL-7702 cells in each of three groups were 69± 11,78±8 and 95±5.There was no significant difference among those three groups (F=2.86,P＞0.05).Conclusion By the pretargeting method,L5 peptide guided SA-PEG-USPIO has effective targeting ability to HepG2 cells in vitro.

Comparison of CT enterography(CTE)and capsule endoscopy(CE)for small bowel diseases / 中华消化内镜杂志

Objective To compare the role of CTE and CE on the diagnosis of small bowel diseases and evaluate their advantages in patients with different indications.Methods Patients underwent both CTE and CE(interval time <2 weeks)at our institution in recent 3 years were enrolled.The positive detection rates,lesion properties and characteristics of CTE and CE were compared.The diagnostic accuracy of combined method was also analyzed.Results A total of 47 patients were enrolled and the indications included suspected or established Crohn′s disease (28 cases),unexplained abdominal pain (14 cases), obscure gastrointestinal bleeding(3 cases),insufficient small bowel obstruction(1 case)and protein losing enteropathy(1 case).Diagnostic yield of CTE and CE for whole small bowel disorders showed no significant difference(CE 83.0% VS CTE 78.7%,P =0.791).For suspected or established CD,CE had a higher diagnostic accuracy than CTE (78.6% VS 35.7%,P =0.002 ),especially in detecting lesions in the jejunum(CE 50.0% VS CTE 7.1%,P =0.002).The diagnostic accuracy reached 100.0% when two meth-ods were combined.For unexplained abdominal pain,no significant difference was found in the diagnostic ac-curacy of CE and CTE(CTE 42.8% VS CE 50.0%,P =1.000).Diagnostic accuracy of combining CTE and CE was 85.7%.Conclusion CTE and CE are both valuable in detecting small bowel lesions.For pa-tients with suspected or established CD,CE is better than CTE.For patients with unexplained abdominal pain,a combination of CTE and CE may be a better strategy than use CTE or CE alone.

Application of multi-sliced CT on breast cancer and early lymph node metastasis / 实用放射学杂志

Objective To investigate the application of multi-sliced CT on breast cancer and early lymph node metastasis (LNM). Methods 30 cases with infiltrative ductal carcinoma (IDC)confirmed by pathology were collected and set as Study Group,30 fibro-mas as Control Group.128-slice CT plain and 2 phrase enhance scan was undergone.Image signs of mass of two groups were com-pared.Image signs of early lymph node metastasis were analyzed.Results In MSCT images,IDC masses had irregular shape,burr rim.2-phrase MSCI demonstrated obvious enhancement in artery phrase,persistence enhancement in vein phrase and ring shape en-hancement.There were significant different between 2 groups in mass shape,rim and enhancement mode(P<0.05).MSCT demon-strated 22 LNM,but 6 of them had no swelling but obvious enhancement.Conclusion 2-phrase MSCT plays an important role in as-sessing breast cancer and early lymph node metastasis.

Live cell fluorescent imaging and cytotoxicity assessment of pH fluorescent probe based on styrylcyanine dyes / 南方医科大学学报

<p><b>OBJECTIVE</b>To prepare a pH fluorescence probe based on styrylcyanine dyes for live cell imaging.</p><p><b>METHODS</b>The Probe 1 was prepared by reaction of 4-pyridinecarboxaldehyde with 1,1,2-trimethylbenz[e]indole. The influence of pH on the fluorescent properties was examined, and the cell viability was examined using cell counting kit-8. The Probe 1 was used as a pH fluorescence probe in living cell.</p><p><b>RESULTS</b>Probe 1 emitted green fluorescence under neutral and basic conditions but orange fluorescence under acid condition. Probe 1 selectively stained the cytoplasmic regions of living cells without significantly affecting the cell viability.</p><p><b>CONCLUSION</b>The pH-sensitive fluorescent probe prepared based on styrylcyanine possesses good ability of cell membrane permeation for live cell fluorescent imaging.</p>

MR imaging findings in cesarean scar pregnancy / 中华放射学杂志

Objective To analyze MRI findings of cesarean scar pregnancy (CSP). Methods The MR findings in 18 patients who were diagnosed as CSP by surgery from March 2010 to November 2011 were retrospectively analyzed,and comparison was made between the MRI findings and surgical results.Results All Gestational sacs (18) were clearly detected by MRI.Among the 18 cases,gestational sac presented as cystic mass with smooth margin located within the scar of uterine wall at the lower anterior uterus in 16 cases.In 2 of the 16 cases,gestational sac was found within the myometrium,whereas in the remaining 14 cases,gestational sac was found partially within the myometrium with extension into the uterine cavity.The anteior wall of isthmus uteri became thinner.In the remaining 2 of the 18 cases,gestational sac presented as irregular,multilobolated mass,growing deep inot the myometrium as well as into the uterinecavity. On T2WI,the mass showed heterogeneous signal intensity. A small amount of hemorrhage within the mass and uterine cavity could be seen on T1 WI. An enhancing solid component with a heterogeneous mass could be seen. All gestational sacs in 18 cases were located at or adjacent to the previous cesarean scar.In the area of cesarean scar,the signal of the uterine wall was disconnected,with focal indentation or thinning and the previous cesarean scar exhibited hypointensity on both T1WI and T2WI.Conclusion CSP has its unique findings on MRI,these specific features can provide useful information in the management of CSP.