Objective To study the quality assurance(QA) and quality control(QC) of PACS image display device in the department of radiology equipped with PACS and radiology information system (RIS). Methods Routine maintenance and periodic calibration were performed using photometer and automatic calibration software according to American Association of Physicists in Medicine Task Group 18 (AAPM TG18) test patterns and evaluating criterion. Digital image and communication in medicine (DICOM) gray scale standard display function (GSDF) standard calibration ,maximum luminance and minimum luminance,luminance uniformity,display resolution and geometry distortion adjustment were performed quarterly on BARCO CRT displays. Results All the results were well conformed to the criteria recommended by the AAPM TG18. About 95 percents of radiological images were interpreted on the PACS diagnostic image display.Conclusion The QC program of PACS image display device is an essential to ensure high-quality in digital medical environment.

Objective To explore the feasibility of low-dose multi-slice computed tomography(MSCT) scan on pulmonary artery three-dimensional angiography, and the relationship between pulmonary VR image quality and the SD value of plain scan. Methods Pulmonary artery CT examination was performed in 87 patients. 63 volunteers were administered with low dose as a low-dose group, and the other 24 were scanned with conventional dose as a routine group. Both plain scans were use conventional dose of pulmonary scan with 150 mAs, and the low-dose pulmonary enhanced scans were used with 60 mAs. The images were post-processed with volume rendering(VR) and classified into three grades A, B and C, and VR image quality levels of both groups compared. The receiver operating characteristic curve( ROC) was used to analyze the relationship between VR image quality level and SD value of plain scan image SD value. Results The VR image level of A-class was 100% in the conventional dose group, and 85. 7% was in the low dose group . According to the correlation analysis between the standard deviation(SD) value of plain scan image and pulmonary artery VR image quality, the area under curve in receiver-operated characteristic analysis was 0. 906. Conclusions The low-dose scan of pulmonary artery three-dimensional angiography is feasible. Using 60 mAs low-dose in pulmonary artery enhanced scan could ensure better image quality. With the SD value of the plain scan decreased, the pulmonary artery VR image quality is improved.

Objective To explore the differences among CT angiography(CTA) at different doses in both lower extremity arteries,and the relationship among volume rendering(VR) image quality,CT number and standard deviation(SD) value.Method CTA in lower extremity artery was performed in 90 patients.The participants were randomly divided into three groups,including a routine group (120 kV,150 mAs),120 kV and 80 mAs group,and 100 kV and 130 mAs group with 30 cases in each group.The images were processed with VR and classified into three degrees,the first class,the second class and the third class,and VR image quality levels of three groups were compared.The receiver operating characteristic curve(ROC) was used to analyze the correlation among VR image quality level,CT number and SD value.Results The percentage of VR image level at the first class was 93.3％ in the routine group,86.6％ in the 120 kV and 80 mAs group and 96.6％ in the 100 kV and 130 mAs group.According to the correlation analysis between the SD value and VR image quality of CTA in lower extremity artery,the area under curve in ROC analysis was 0.9078.According to the correlation analysis between the CT number and VR image quality of CTA in lower extremity artery,the area under curve in ROC analysis was 0.9116.Conclusions The low-dose CAT in lower extremity artery is feasible.Application of 100 kV and 130 mAs could ensure better image quality.

OBJECTIVETo analyze the influence of retinoic acid (RA) on the undifferentiated state and EB formation abilities of human embryonic stem cells.

METHODSThe biological characteristics of H9 ESCs after RA treatment were characterized by real-time PCR, MTS proliferation assay and immunofluorescence staining. The expression of three germ layers markers, osteogenic differentiation markers and adipogenic differentiation markers in H9-differentiated embryoid bodies (EBs) with RA treatment were quantified by real time PCR.

RESULTSThe proliferation of H9 ESCs in the early logarithmic growth phase was accelerated by RA treatment. In addition, RA induced differentiation of H9 ESC coupled with morphology changes, decreased expression of undifferentiated markers Oct4, Nanog, Sox2 and OCT4 mRNA binding protein Lin28 at mRNA level, and reduced expression of Oct4 at protein level. RA induced formation of cavities in EBs. Real time PCR results showed that the expressions of ectodermal markers: NeuroD1, Noggin; mesodermal markers: Brachyury, Twist and endodermal markers: AFP, GATA-4 were significantly increased (P < 0.05), especially for AFP (P < 0.01), by RA treatment in a dose-dependent manner. In addition, the expression of adipogenic differentiation marker C/EBPalpha was increased while the osteogenic differentiation marker OPN was decreased in EBs after RA treatment for 5 days.

CONCLUSIONSHigh concentrations of RA induced the loss of stemness in H9 ESCs and excessive differentiation in EBs, and damaged the balance between osteogenic and adipogenic differentiation during early EB differentiation, which may be relevant to the congenital malformations.

Cell Differentiation ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Embryonic Stem Cells ; cytology ; drug effects ; Humans ; Tretinoin ; pharmacology

Background and purpose: Oxymatrine, which is the main effective component of Sopkora flavescens Ait, has anti-fibrosis and antiviral activities, and also has a good effect on leukopenia after either chemotherapy or radiotherapy. Recent studies showed that oxymatrine has the abilities of anti-invasion and killing tumor cells in some degree, and as a supplementary anticancer drug in chemical therapy. In this study, we investigated the antitumor mechanism of oxymatrine by observing cell proliferation and VEGF expression in human gastric cancer SGC-7901 cell line. Methods: Human gastric cancer SGC-7901 cells was cultured in vitro and treated with oxymatrine, then cell proliferation was examined by the method of MTT. Immunohistochemistry was applied to examine the protein expression of VEGE The transcriptions of VEGF mRNA were demonstrated by RT-PCR technique.Results: Low-dose (0.5 mg/mL) oxymatrine has a mild inhibitory effect on cellular proliferation of SGC-7901 cells (P>0.05). When concentration exceeded 1 mg/mL, oxymatrine significantly inhibited cellular proliferation in a time-and concentration-dependent manner, and down-regulated the mRNA and protein expression of VEGF (P<0.05).Conclusion: Within a certain drug concentration, oxymatrine can inhibit the proliferation of SGC-7901 cells and play a potential role in inhibiting angiogenesis by down-regulating the expression of VEGF.

Objective To investigate the imaging features of splenic littoral cell angioma (LCA)and correlate with pathological findings.Methods Ten patients of LCA with pathologically confirmed diagnosis were included in this study.A retrospective review of clinical data and imaging findings on CT and MRI was performed,along with review of the literature.Results Splenic littory cell angiomas presented with multiple nodules of varying sizes with a predoninance of small ones.Nine of 10 patients had clinical symptoms of splenomegalia and hypersplenia.MR T2WI and DWI showed masses with high-signalintensity.The CT and MRI enhancing pattern of LCA was similar to splenic hemangioma.There were many mammiliform structures pointing inside in the wall of the vascular channels,a hallmark feature allowing its differentiation from splenic hemangioma pathologically.Conclusion The CT and MRI findings of LCA can show some of its characteristic signs,especially on DWI,which can assist to identify LCA in clinical practice.

Objective To evaluate the renal oxygenation in patients with primary nephrotic syndrome (PNS) using BOLD MRI.Methods Twenty patients with untreated first-onset PNS and 18 healthy control subjects underwent BOLD MRI.The R2* of renal cortex and medulla were measured.Blood and urine samples were obtained on the day of MRI,and the patients underwent renal biopsy after MRI.The renal tubulointerstitial damage scores (TIDS) were determined using Katafuchi criteria.All patients received corticosteroids within 7 days after MRI and were followed up for 12 months.The difference of R2* levels between the PNS patients and controls were compared,and the correlations between R2* values and TIDS,laboratory parameters (eGFR,etc.) were tested.Results R2* values of renal medulla in PNS patients significantly decreased compared that of the controls (t =-9.270,P＜0.001).R2* values of renal medulla in PNS patients were negatively correlated with eGFR (r=-0.462,P=0.040) and positively correlated with TIDS (r=0.809,P＜0.001).There was a slight tendency for higher R2* values of renal medulla in individuals with poor prognosis.Conclusion BOLD MRI is a noninvasive method for the detection of renal oxygenation changes,which can evaluate the renal function and tubulointerstitial impairment,as well as prediction of the prognosis for PNS patients.

In this study ,we intended to prepare anti‐Toxoplasma gondii aquaporin (TgAQP) peptide antibody which was used to the application in the detection of the aquaporin expression and its subcellular localization of Toxop lasma gondii (T .gondii) ME49 strain .The B cell peptide antigen was designed based on the TgAQP amino acids sequence .After the pep‐tide antigen was conjugated to the KLH ,the fusion antigen was injected into New Zealand rabbits to prepare polyclonal anti‐body ,followed by identification of ELISA ,Western‐blotting and immunofluorescence assays .The ELISA showed that the titer of anti‐TgAQP antibody was about 1∶40 000 .Western blotting revealed the specific affinity of the antigen to polyclonal anti‐body at 29 .9 kDa protein T .gondii .The protein detected by the indirect immunofluorescence assays was distributed in the cy‐toplasm of the parasite .Thus far ,the anti‐TgAQP polyclonal antibody was successfully prepared ,providing a useful tool for further study of biological function and metabolic characteristics of TgAQP .

Objective To explore the pathological and imaging characteristics of focal nodular hyperplasia(FNH) of liver.Methods 17 cases of FNH proven pathologically underwent triphase spiral CT scan,of them,10 cases underwent fast MR imaging.The pathological andimaging features were comparatively analysed.Results All lesions were a solitary globular or lobulated mass,the majority of cases wasapproximately 2~5 cm in diameter.On plain CT and MRI,FNH was classically seen as a solitary,homogeneous and slightly hypoattenuating or isoattenuating area in comparison with normal liver,slightly hyper-or isointense on T_2WI,intense homogeneous enhancement during the arterial phase of enhanced imaging,and hyperattenuating in 12 cases,hypoattenuating or isoattenuating in 6 cases in comparison with normal liver during venous and delayed phase.The central scar was showed in 11 cases during delayed phase and 8 cases showed delayed enhancement,4 cases had pseudocapsular like enhancement in delayed images.In histology,17 cases of FNH were well limited but nonencapsulated,the hyperplastic parenchyma of the liver was subdivided into small nodules surrounded by the fibrous septa,there was a central scar composedof fibrous connective tissue and malformed vessels of various caliber.Conclusion The typical FNH can be easily diagnosed,while theatypical cases should be differentiated from hepatocelluar adenoma,hepatocellular carcinoma and hemangiomas.

Objective To explore the feasibility and reasonable of low-dose scan on abdominal angiography in 64-slice spiral helical CT. Methods Phantom test: at 120 KV and from 200 mAs to 30 mAs at an interval of 10 mAs in each image acquisition, it was measured standard deviation (SD) of CT number, high contrast resolution and low contrast resolution, and then analyzed the relationship between the three parameters and the mAs values. Three mAs values were chosen to undertake clinical analysis.Clinical analysis: 90 randomly selected objects with abdominal angiography were divided into three groups,scanning with above three mAs values.Measurement of the SD value at the plain scan images was performed and the enhanced low-dose scan images were used post-processing with three-dimensional volume reconstruction (VR). The VR images were classified into three grades (excellent, moderate, bad) with the blind evaluation of three CT radiologists. The quality-correlation analysis was used between the standard deviation (SD) values of plain scan image and abdominal angiography VR image. Results According to the quality-correlation analysis between the standard deviation (SD) value of plain scan image and abdominal angiography VR image, the area under curve in receiver-operated characteristic (ROC) analysis was 0.921, 0.906 and 0.893 in each three group, respectively. Conclusions The low-dose scan of abdominal angiography is feasible. 80mAs can ensure better image quality. The enhanced scan probably can use 60mAs when the SD value is less than 5.78 in the plain scan; but when the SD value of plain scan is greater than 11.8, the enhanced scan is used best 100 mAs or higher.