Objective To compare the value of dynamic contrast-enhanced MRI(DCE-MRI) and diffusion weight-imaging(DWI) in differentiating hepatic epithelioid angiomyolipoma (HEAML) from hepatocellular carcinoma(HCC).Methods The MR data of 15 HEAML and 50 HCC proved surgically and pathologically were analyzed retrospectively.The DCE-MRI and DWI were performed preoperatively.The size, location, margin, T1-weighted images(T1WI),T2-weighted images(T2WI) and DWI signal intensity(SI),enhancement pattern, central vessel, early draining vein, pseudocapsule were recorded.The apparent diffusion coefficient (ADC) value was also calculated.The differences of these MR features between two groups were compared statistically.Results There was one lesion in each patient.For all 15 HEAML lesions, early draining vein, central vessel and pseudocapsule were displayed in 8,11 and 6 lesions, respectively.The wash in and slow out enhancement pattern was shown in 10 lesions and wash in and wash out pattern shown in others (5/15).The mean ADC value was (1.15±0.31)×10-3 mm2/s.For all 50 HCC lesions, early draining vein, central vessel and pseudocapsule were displayed in 6,5 and 45 lesions, respectively.29 lesions were shown as wash in and wash out enhancement pattern and the others (21/50) as wash in and slow out pattern.The mean ADC value was (1.23±0.29)×10-3 mm2/s.There were significant differences in these MR features including draining vein, central vessel and pseudocapsule (P<0.05), but no differences in size, location, margin, SI(T1WI, T2WI and DWI), dynamic enhancement pattern, ADC value(P>0.05) between HEAML and HCC.Conclusion DCE-MRI is more helpful in differentiating HEAML from HCC than DWI.

Objective To investigate the diagnostic value of conventional and dynamic gadolinium-enhanced T1-weighted (T1W) MRI in benign and malignant endometrial polypoid lesions. The pathologic basis of MRI features was also evaluated. Methods The conventional and dynamic contrast enhanced MRI features in 48 cases with clinicopathologically-proved endometrial polypoid lesions were retrospectively analyzed, including 26 cases with malignant tumors (23 eases with endometrial carcinoma and 3 cases with endometrial sarcoma) and 22 cases with benign polypoid lesions (12 cases with endothehal polyps and 10 cases with submucons leiomyomas). The occurrence probability of central fibrous core, intratumoral cysts and intact junctional zone were evaluated by Fisher's exact test. Results Benign and malignant endometrial polypoid lesions had specific characteristics on MRL Endometrial carcinomas usually appeared as homogeneous intermediate or slightly high signal-intensity masses on T2-weighted images, and relatively homogeneous hypedense masses on contrast-enhanced images with myometrial invasion (P < 0.05). An irregular central fthrous core and small non-enhanced intratumoral cysts were seen more frequently in endometrial polyps (P < 0.05) than others. All 3 cases with uterine sarcomas showed obviously inhomageneous intensity on T2WI and demonstrated areas of early and persistent marked enhancement.Submucous leiomyomas demonstrated isodense or slightly low-density masses with defined outline on T2 WI and the endomerium was displaced. The diagnostic sensitivity, specificity and accuracy of malignant polypoid masses were 92.3% (24/26), 83.3% (20/24) and 95.8% (46/48) respectively. Conclusion Conventional and dynamic contrast-enhanced MRI are valuable in characterizing the benign and malignant endometrial polypoid lesions.

ObjecfiveTo compare the sensitivity of diffusion weighted imaging(DWI)with dynamic contrast enhanced(DeE)MRI for the detection of small breast caJlcers and to evaluate the clinical value of DWI.MethodsForty-eight patients with benign(n=25)and malignant(n=45)small breast lesions(≤2 cm)proved by pathology underwent DWI and DCE MRI.The DCE MRI was performed using FLASH sequence and the time-signal intensity chive was drawn.The DWl was performed using GRAPPAEPI sequence with different b values(800,1000 s/mm2) and the ADC values of lesions were measured.The sensitivity and specificity of DWI for the detection of small breast cancers were compared with DCE MRI. ResultsForty of 45 small breast cancers and 19 of 25 small benign breast lesions were corrlectly diagnosed using DCE MRI.The sensitivity and positive predictive value of TIC were 88.9%(40/45)and 87.0%(40/46).With b values of 800 s/mm2 and 1000 s/mm2,the avemge ADC values of small breast cancers were(1.153±0.192)× 10-3 and(1.079±0.186)× 10-3 mm2/s,while those of benign ones were (1.473±0.252)×10-3 and(1.419±0.255)×10-3 mm2/s,respeetively. There was no significant difference for the ADC values with different b values in the same group(P＞0.05),while there was a signiticant difference between the malignant and the benign lesions(P＜0.05)Thirty-nine of 45 small breast cancers and 19 of 25 small benign breast lesions were correctly diagnosed using DWI with b value of 1000see/mm2.Both the sensitivity and positive predictive value of diagnosis were 86.7%(39/45).The abilities of DWI and DCE MRI for the diagnosis of small breast cancers werle the same. The sensitivity(93.3%)and positive predictive value(91.3%)were improved with the combination of DCE MRI and DWI. Conclusion DWI has a high sensitivity for the detection of small breast cancers,the ADC value can provide valuable information in the differential diagnosis.

Objective The purpose of this study is to assess the value of multi-slice spiral CT(MSCT)in the preoperative evaluation of living renal donor as a all in one modality.Methods Thirty-six potential living renal donors underwent the examination using a GE light VCT scanner.Informed consent was obtained from all participants.The plain scan,early arterial phase,late arterial phase and excretory phase scans are performed in the former 25 donors(injection rate 5 ml/s,total volume 100 ml,tube tension 120 kV).While in the later 11 donors(2 ml/s 40 ml+4 ml/s 60 ml),the scanning protocol included the plain scan(100 kV),vascular phase and excretory phase scans(100 kV).The excretory phase data were used in the reconstruction of CT urography in both groups.All images were reviewed by one radiologist and one urologist,and the findings of MSCT were compared with intraoperative findings for 33 donors,to investigate the utilities of MSCT in assessing renal vascularity,urinary tract and lesions of renal parenchyma.When discrepancies are found between the two reviewers,consensus was obtained via discussion.Au data was statiscally processed with SPSS for Windows.Results MSCT angiography is in accordance with intraoperative findings in demonstrating the anatomy of renal arteries and renal vein trunk,accesary arteries,early branching of renal artery.The findings from CTA are highly in accordance with the intraoperative findings,which facilitate intraoperative ligation and reduce relevant complications.CTU demonstrates the anatomy of urinary tract in good agreement with the intraoperative findings.The image quality of 3D vascularity and CTU between the two groups.scored 4.4±1.2 vs 4.2±1.3 and 4.6±0.8 vs 4.4±0.9 respectively,no statistical between-groups difference was found(Z=-0.89,-0.47,P＞0.05).Conclusion MSCT multiphase scanning combined with CTA and CTU play a important role in the evaluation of living renal donor,which preoperatively provide detailed information of renal vascularity,urinary tract and renal parenchyma as a all-in-one modality.

ObjectiveTo investigate the feasibility of examining aortic pulse wave velocity (PWV),aortic distensibility (AD) and brachial artery flow-mediated dilation (FMD) by means of highresolution 3.0 T MRI.MethodsA total of 32 healthy volunteers underwent high-resolution MRI to assess aortic PWV,and AD in ascending aorta (AA),proximal descending aorta (DA),distal descending aorta (DDA) and FMD of the brachial artery with repeat examination performed in 1-2 hours.PWV was evaluated by 2D Phase Contrast (PC) velocity-encoded MRI with a 4.7-7.8 ms temporal resolution.Fiesta-cine MRI was used to assess AD and FMD with a 18.75-31.25 ms temporal resolution.The image quality of these two scans was scored and the agreement between them was tested with Kappa analysis.The reproducibility of the results between repeated measurements of PWV,AA-AD,DA-AD,DDA-AD and FMD was assessed with intra-class correlation coefficient (ICC) analysis.The method of Bland-Altman plot was used to assess the agreement between results of repeated studies.Results Each examination including PWV,AD and FMD were completed in about half an hour.The image quality between repeated scans showed good agreement ( Kappa value 0.776 ) with the score of ( 3.53 ± 0.62 ) and ( 3.41 ± 0.67 ) respectively.Reproducibility between repeated measurements was high for aortic PWV [ (4.33 ± 0.88 ) vs ( 4.36 ±0.88) m/s],AA-AD [(8.60±3.11) × 10-3 vs (8.59 ± 3.10) × l0-3/mm Hg(1 mm Hg =0.133 kPa) ],DA-AD[ (6.95 ±2.44) × 10-3 vs (6.95 ±2.42) × 10-3/mm Hg],DDA [(10.54 ±2.91) ×l0-3 vs (10.55 ±2.90) × 10-3/mm Hg] and FMD [(24.94 ± 12.55)％ vs (24.92 ±1 2.38 ) ％ ].ICC were 0.95,0.97,0.99,0.98 and 0.94,P ＜ 0.01.Excellent agreement between repeated measurements was found for aortic PWV [ confidence interval (CI) between - 0.55 and 0.50 ],AA-AD ( CI between - 0.11 and 0.12 ),DA-AD ( CI between - 0.08 and 0.08 ),DDA-AD ( CI between - 0.23 and 0.21 ) and FMD (CI between - 1.46 and 1.51 ).The maximum difference percentage in minimum average for aortic PWV,AA-AD,DA-AD,DDA-AD and FMD was 38.53％,9.65％,3.86％,5.68％,42.37％,respectively,all less than 50％.Conclusion Comprehensive assessment of aortic compliance and brachial endothelial function can be achieved using 3.0 T high-resolution MRI with excellent reproducibility and within a reasonable amount of time.

Objective To investigate the imaging features of focal nodular hyperplasia and hepatocellular carcinoma on DWI. Methods The data of patients with histopathologically confirmed FNHs and HCCs between August 2008 and November 2010 were collected. A total of 24 patients with 26 FNH lesions and 36 patients with 39 HCC lesions were included in our study. All patients underwent breath-hold DWI with b = 500 s/mm2 and dynamic contrasted-enhanced (DCE) MRI. The imaging findings of FNHs and HCCs were retrospectively analyzed and compared. The signal intensity (SI) of the lesions on DWI were classified as iso-, slightly high, high SI and the distribution of SI between FNHs and HCCs was compared with Fisher exact test. ADC value and lesion-to-liver ADC ratio of FNHs and HCCs were measured and compared by using independent sample t test. ROC was performed to assess the diagnostic value of ADC value and lesion-liver ADC ratio in the characterization FNHs versus HCCs. Results Of 26 FNHs,23 manifested as isointensity or slightly high SI on DWI, but most 25 out of 39 HCCs showed high SI. The distribution of SI between FNHs and HCCs had significant difference ( P = 0. 000). The mean ADC value and lesion-liver ADC ratio for FNHs [ (1.76 ± 0. 62 ) × 10-3 mm2/s and 1.06 ± 0. 18, respectively ] were significantly higher ( P = 0. 001, P = 0. 000, respectively ) than those for HCCs [ ( 1.26 ± 0. 46 ) × 10-3mm2/s and 0. 79 ±0. 12, respectively]. The area (Az) under the ROC for the ADC value and lesionliver ADC ratio for the differentiation of FNHs versus HCCs were 0. 79 ± 0. 05 and 0. 85 ± 0. 05,respectively, with no significant difference (P =0. 270). The specificity of the two measures was 69. 23% and 97.44%, respectively, with significant difference (P = 0. 001 ). Conclusion FNH shows isointensity or slightly high SI with relatively higher ADC value and lesion-liver ADC ratio than those of HCCs on DWI,which is characteristic for its diagnosis and differentiation.

Objective To investigate the chondrogenic feasibility of the human umbilical cord derived mesenchymal stem cells (hUCMSCs)as cartilage tissue engineering seed cells ,type Ⅱ collagen composite glycosaminoglycan scaffold as the cellular carrier and cell‐scaffold complex .Methods The type Ⅱ collagen composite glycosaminoglycan scaffolds was prepared .The pore diameter , porosity and hydrophilia of scaffold materials were observed and measured by electronic microscope .The corresponding histological analysis on the scaffold materials was performed .hUCMSCs of P3 generation were cultured and identified .The hUCMSCs suspen‐sion was inoculated in the type Ⅱ collagen composite glycosaminoglycan scaffold for conducting culture without adding inducer .The samples were taken out after 3 weeks and performed the toluidine blue and safranin O staining ,type Ⅱ collagen immunohistochemi‐cal staining and SEM scanning .Results hUCMSCs of P3 generation highly expressed the mesenchymal cell marker CD29 and CD105 ,while hardly expressed endothelial cells of CD34 and hematopoietic cell markers .The type Ⅱ collagen composite glycosami‐noglycan scaffold presented white porous foam like ,the porosity was (91 .8 ± 2 .17)% ,the average pore diameter was 110‐230 μm , which was homogeneously distributed and had interpenetration .The scaffold showed good hydrophilicity with the water absorption expansion rate of (213 .71 ± 1 .31)% .The scaffold staining of toluidine blue ,safranin O and type Ⅱ collagen was positive .The car‐tilage‐like tissues were observed ,and gradually increased in the surface of cell‐scaffold complex along with culture ,which were posi‐tive in Toluidine blue ,safranin O and type Ⅱ collagen staining ,the electronic microscopic observation displayed that the cells were actively proliferated in the scaffold ,closely adhered with the materials ,the cartilage‐like cells and a large number of peripheral colla‐gen fibers with zigzag connection could be seen .Conclusion Compositing hUCMSCs and type Ⅱ collagen composite glycosamin‐oglycan scaffold could construct tissue‐engineering cartilage in vitro without induction ,which lays a certain experimental foundation for the repair of cartilage damage .

Objective:To explore the clinical and CT imaging features of immune checkpoint inhibitor-associated pneumonia (CIP) and to improve the early diagnostic ability of CIP.Methods:From June 1, 2020 to October 31, 2021, the clinical data and chest CT images of 2 067 patients with advanced malignant tumor treated with immune checkpoint inhibitor (ICI) in the First Medical Center, Chinese PLA General Hospital were retrospectively analyzed. Patients with CIP were enrolled according to the guidelines for CIP diagnosis, and the incidence, time from the start of medication to the onset of CIP, medication cycle, imaging features, imaging patterns, CT grade and outcomes were analyzed. χ 2 test was used to compare the incidence of CIP in patients with or without basic lung disease. Results:Among 2 067 patients with malignant tumors treated with ICI, 67 patients developed CIP, the incidence of CIP was 3.2%. The incidence of CIP was significantly different between 386 patients with basic lung disease (7.00%, 27/386) and 1 681 patients without basic lung disease (2.4%, 40/1 681) (χ 2=21.32, P<0.001). The time from the start of medication to the onset of CIP was 7-367 d (median 52 days), and the duration of medication was 1-12 cycles (median 2 cycles). The imaging features of CIP presented as ground glass opacities in 54 cases (80.6%), solid nodules in 26 cases (38.8%), consolidations in 25 cases (37.3%) and irregular reticular opacities in 24 cases (35.8%). The main radiologic pattern was organizing pneumonia (OP, 34 cases, 50.7%), and followed by diffuse alveolar damage (DAD) pattern (14 cases, 20.9%). According to CT grading, there were 26 cases in low risk grade, 17 cases in moderate risk grade and 24 cases in high risk grade. Of 43 low-and medium-risk grade cases, 25 were OP pattern, accounting for 58.1%, and among 24 high-risk grade patients, 13 were DAD pattern, accounting for 54.2%. Forty-three of the 52 patients were initially untreated, of which 23 patients progressed, 17 had lesion shrinkage, and 3 had resolution, and relapsed in 8 cases after resolution or drug withdrawal. Conclusions:The imaging manifestations of CIP are mainly ground glass opacities, nodules, consolidations, and irregular reticular opacities. The radiologic patterns are mainly OP and DAD. OP is the most common pattern in low-moderate risk grade CIP and DAD is the most common pattern in high risk grade CIP. Patients with basic lung disease are more likely to get CIP.

Objective To compare the compressed sensing (CS)and parallel imaging (PI)techniques applied to contrast-enhanced MRI (CE-MRI)scanning of liver and to determine their clinical applicability.Methods Thirty patients with liver mass who underwent the CE-MRI scanning with both CS and PI techniques were recruited in the current study.The SNR of the liver,acquisition time and subjective image quality scores were compared between CS (CE-MRI with CS)and PI (CE-MRI with PI)groups respectively.Results The SNR values of pre-enhancement T1 WI in CS group were lower than those in PI group (1 97.82±32.5 3 vs 204.94±35.28,P＜0.05).However,there was no significant difference in the SNR values of images in equilibrium phase between the two groups (CS vs PI:392.38±72.93 vs 405.03±82.09,P＞0.05).The acquisition time in CS group was significantly shorter than that in PI group [(11.71±0.23)s vs (17.85±0.42)s, P＜0.01].Significantly higher subjective image quality scores were found in CS group than those in PI group (3.54±0.57 vs 2.91±0.80,P＜0.01). Conclusion CS technique may benefit the patients who cannot hold breath well and improve the CE-MRI image quality.

Objective To study the clinical features of hepatic pseudolymphoma.Methods A retrospective study was conducted on 19 patients with hepatic pseudolymphoma who were diagnosed and treated at Zhongshan Hospital in Shanghai from June 2013 to December 2017.Eighteen patients were females and one was a male.The mean age was (55±9) years,range 36 to 68 years.This study mainly analyzed the imaging features,treatment and postoperative results.Results All patients were diagnosed accidentally,and 78.9％ patients did not exhibit any evidence of hepatic B viral infection.A monofocal lesion was found in 14 patients and multifocal lesions in 5 patients.Surgical treatment was performed in all the patients.The lesion size was (1.1±0.4) cm (range 0.5～2.4 cm).Ultrasound revealed hypo-or slightly hypo-echogenicity.On MRI,diffusion weighted imaging showed slight hyperintensity or hyperintensity,all lesions manifested as homogeneous and slightly hyperintensity on T2WI and hypointensity on T1WI.Dynamic enhancement pattern,wash in and wash out,degressive and persistent enhancement were observed in 16(55.2％),12(41.4％),and 1 (3.4％) patients,respectively.More than 70％ of lesions were diagnosed as malignant tumors on preoperative imaging.During a follow-up of 6 ～ 44 months (median:19 months),no patient developed metastasis or recurrence.Conclusions Hepatic pseudolymphoma commonly occurred in women with a small sized lesion.Due to the lack of specific clinical manifestations and imaging findings,preoperative diagnosis was difficult.Surgical resection is still the most optimal treatment.The patients usually have favorable prognosis.