Objective To describe the characteristic MR appearances in hepatocellular carcinoma after radiofrequency ablation (RFA) during follow-up studies. Methods MR images of 110 patients with hepatocellular carcinoma after RFA ,which were categorized into 3 MR examination intervals ( ≤48 h, 1-6 m, ＞6 m), were analyzed retrospectively. The sequential changes of MR images were assessed and compared using Chi-square test. Results All RFA areas of 110 patients typically exhibited hyperintensity on GRE-T1 WI and hypointensity on TSE-T2 WI with fat suppression within 48 h after ablation. Subsequently,the signal intensities of the RFA areas decreased on GRE-T1 WI which showed significant differences after 6 months( P ＜0. 015 ). On GRE-T1 WI , RFA lesions were hyperintense in 72, iso-or hypo-intense in 4 at 1-6 months and hyperintense in 60, iso-or hypo-intense in 17 after 6 months. On TSE-T2 WI, 65 RFA lesions were hypointense, 11 isointense at 1-6 months and 47 were hypointense, 30 isointense after 6 months. The increased intensity on TSE-T2 WI showed significant differences after 6 months( P ＜ 0. 015 ).On contrast-enhanced MR images, RFA lesions showed peripheral rim of enhancement within 48 h and exhibited a tendency to show no enhancement ( n = 37 at 16 months and n = 63 after 6 months ) with significant differences between MR examination intervals( P ＜ 0. 015 ). In 6 patients with residual tumor or local tumor progression, nodular lesions were found at the periphery of the RFA. These nodular lesions showed moderate to marked enhancement as well as hypointense signal on GRE-T1WI, and moderate hyperintense signal on TSE-T2WI. Conclusion MR imaging could depict the characteristics of coagulative necrosis of tumor, residual tumor or local tumor progression in patients with hepatocellular carcinoma after RFA therapy.

Objective To discuss the diagnostic value of CT and MRI for primary anorectal malignant melanoma(AMM).Methods 5 patients(2 males and 3 females)with AMM confirmed pathologically were analyzed retrospectively,which were examined by CT(n=4)and 1.5T MRI(n=1).Results AMM presented as bulky intraluminal fungating masses without intestinal obstruction(n=4)and irregular rectal wall thickening(n=1).2 cases had perirectal fat infiltration and extended to the presacral space in one case,4 cases had perirectal enlarged lymph nodes and larger than 3 cm in diameter in one case.Nonenhanced CT showed a hypodense lesion and contrast-enhanced CT showed slight enhancement(n=1)and mild enhancement(n=3).The tumor scanned by MRI depicted high intensity on T1WI and low intensity on T2WI,so did the enlarged lymph nodes and bone metastasis.Fat-saturation T1WI significantly improved the extention of tumor and detection of metastasis.Conclusion Bulky intraluminal fungating masses without intestinal obstruction,perirectal fat infiltration and enlarged lymph nodes may be helpful to diagnose AMM.MRI is especially useful in differentiating melanotic AMM from other rectal tumors.

Objective To investigate the value of syngo WARP technology for spine MR imaging in patients with metallic prosthesis.Methods Twenty-five patients with metallic prosthesis in cervical spine or lumbar spine were prospectively included in this study.Both conventional MR sequences and optimized sequences with syngo WARP were applied in all patients.Acquisition time and image quality of two sequences were compared using a paired t test.Results All patients were examined successfully.Scanning time of cervical spine was 8 min 16 s vs.12 min 45 s for conventional sequences and syngo WARP optimized sequences respectively,with a significant difference (t =7.963,P ＜ 0.01).Scanning time of lumbar spine was longer by syngo WARP optimized sequences compared with conventional sequences (11 min 53 s vs.9 min 16 s),with a significant difference (t =4.904,P ＜ 0.01).However,image quality was better for syngo WARP optimized sequences compared with conventional sequences (4.22 ± 0.67 vs.3.56 ± 0.53 ;t =3.364,P =0.002).STIR with syngo WARP could optimize the signal loss of metallic prosthesis surrounding tissues,and significantly improve image distortion and blurring compared to the conventional sequence.Conclusion Syngo WARP technique could effectively reduce metal artifacts and better display metal implant surrounding tissue and anatomical structure with potential clinical value.

Objective To analyze the computed tomography(CT)and magnetic resonance imaging (MRI)appearances of primary clear cell carcinoma of the liver (PCCCL)and evaluate the value in the diagnosis of the disease.Methods CT and MR images of 38 patients of pathologically confirmed PCCCL were evaluated retrospectively.Twenty-six patients underwent CT,23 underwent MRI, and 1 1 underwent both CT and MRI.Results In pre-contrast CT scanning,24 PCCCLs appeared hypodense and 2 hyperdense.As for MRI 1 9 of the 23 PCCCLs were hypointense and 4 were iso-hypointense on T1 WI.While on T2 WI,22 cases were heterogeneously hyperintense,and 1was iso-hypointense.On the arterial phase of CT/MRI,all cases presented intense enhancement,and on the portal venous phase,35 cases(35/38,92.1%)were relatively hypodense/hypointense and 3 were slightly hyperdense/hyperintense.Among the tumors larger than 3 cm(n=22),nodular enhancement pattern was found in 14 cases(63.6%,14/22).The capsular rim en-hancement was demonstrated in 26 cases.Conclusion PCCCL showed similar dynamic enhancement pattern as common hepatocellu-lar carcinoma,but also depicted specific imaging features.

Objective To investigate the imaging features of primary clear cell carcinoma of liver and to assess the role of CT and MRI in the diagnosis of the disease. Methods Nineteen cases of primary liver clear cell carcinoma of liver were collected. All cases were confirmed by operation and pathology. Both pre-contrast and post-contrast scans with spiral CT were performed in 13 cases. MRI with T1WI, T2WI, and dynamic multi-phase contrast scanning were performed in 8 cases. Imaging findings in all cases were retrospectively reviewed. Results On pre-contrast CT scans, all 13 lesions appeared as hypodensity and among them irregular more hypodense region was found in 9 cases. On the arterial phase, all cases showed obvious enhancement, among which 9 cases were enhanced heterogeneously with central non-enhanced area.On the portal venous phase, 11 lesions were hypodense compared with normal live parenchyma and 2 lesions were isodense. The rim enhancement of tumor capsule was demonstrated in 3 cases. On MR T1WI, 5 of 8 were hypointense and 3 were slightly hyperintense. On MR T2WI, 5 of 8 cases were heterogeneously hyperintense, and 3 were iso-hypointense. On the MR arterial phase, marked enhancement was found in all 8 cases. On the portal venous phase and delayed phase, 7 of 8 cases were hypointense and 1 was isointense.The rim enhancement of tumor capsule was found in 2 cases. Conclusion CT and MRI can display the characteristic features of primary clear cell carcinoma of liver and can be helpful to improve the diagnostic accuracy.

Objective To investigate imaging characteristics of multistep hepatocarcinogenesis in cirrhotic livers on susceptibility-weighted imaging (SWI).Methods Seventy-three patients with 83 nodules in cirrhotic livers underwent hepatic MR imaging with SWI.Two radiologists reviewed MR images by consensus.Imaging characteristics of dysplastic nodules (DN),DN with malignant foci and hepatocellular carcinoma (HCC) were evaluated.Prussian blue staining was performed for semiquantification of hepatic iron content and above cirrhosis-associated nodules.Results Positive iron staining of background liver parenchyma was found in 69 of 73 patients and 4 HCC patients showed iron-negative staining of background liver parenchyma.Nine DNs appeared as hypointensity or isointensity with pathologically confirmed similar (n =7) or slightly decreased (n =2) iron deposition compared with background liver parenchyma.SWI detected 14 of 15 DNs with malignant foci.Seven patients appeared as homogeneous hyperintensity and 1 patient appeared as heterogeneous hyperintensity due to intratumoral hemorrhages.The remaining 6 patients demonstrated as nodule-in-nodule appearance with iron deposition in all background nodules,iron deposition with grade 1 in one internal HCC foci,and iron-free in 5 internal HCC foci.The remaining 50 patients with hepatic iron deposition had 55 HCC lesions.Three HCC lesions had iron deposition with grade 1 to 2 and the remaining 52 HCC lesions were pathologically iron-resistant.HCC appeared as hyperintensity compared with siderotic surrounding liver parenchyma.However,HCCs with diameter larger than 3 cm usually demonstrated heterogeneous hyperintensity due to intratumoral hemorrhage.Conclusions SWI could accurately demonstrate dynamic iron depletion on multistep hepatocarcinogenesis in cirrhotic livers.On SWI images,DNs appear as hypointensity due to siderosis and malignant nodules appear as hyperintensity due to iron depletion.

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 value of susceptibility?weighted imaging (SWI) for characterization of small hepatocellular carcinoma (sHCC) in cirrhotic livers. Methods Two hundred seventy?two patients suspiciousof HCC underwent conventional MR imaging and susceptibility?weighted imaging (SWI). Two hundred and five patients were excluded due to either size larger than 3.0 cm, no cirrhosis or HCC. Finally, a total of 84 hepatocellular nodules in 67 patients were included in this prospective study. There were 22 DNs in 12 cases, 8 DNs with HCC foci in 7 cases, and 54 overt HCCs in 48 cases. Two abdominal radiologists independently evaluated signal intensity and enhancing pattern using conventional MRI set and conventional MRI combining with SWI set. A five?point scale was performed to evaluate diagnostic confidence of HCC. Kappa analysis was performed to assess interobserver agreement of the two sets by two readers.The diagnostic performance and confidence level were compared for each image set,ROC was used to evaluate the diagnostic efficiency.Results Good interobserver agreement was identified with a Kappa value of 0.923 for conventional MRI set and 0.865 for conventional MRI combining with SWI set, respectively. The diagnostic sensitivity, specificity, accuracy, and area under the alternative?free response ROC (Az) were 80.6% and 80.6%, 81.8% and 77.3%, 81.0% and 79.8%, 0.804 and 0.782 using conventional MRI set, and 93.5%and 85.5%, 90.9%and 86.4%, 92.9%and 85.7%, 0.898 and 0.859 using conventional MRI combining with SWI set for reader 1 and reader 2, respectively.The diagnostic confidence level of conventional MRI combining with SWI set for diagnosis of HCC with less than 2 cm in size(n=36) was significantly higher than that of conventional MRI (reader 1, 3.86±0.47 vs 3.40±0.91;reader 2, 3.85±0.57 vs 3.41±0.92;t values were 3.733 and 2.468, P were 0.001 and 0.018).Conclusion SWI can provide additional valuable information and improve diagnostic performance for characterization of sHCC in cirrhotic livers.

Objective:To evaluate the prognostic value of plasma microRNA-30b-5p (miR-30b-5p) combined with extravascular lung water index (EVLWI) in patients with acute respiratory distress syndrome (ARDS).Methods:120 ARDS patients admitted to Danzhou People's Hospital from January 2016 to June 2019 were enrolled. The gender, age, body mass index (BMI), underlying diseases, etiology and baseline values of heart rate (HR), respiratory rate (RR), oxygenation index (OI), arterial partial pressure of carbon dioxide (PaCO 2) and acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) score were collected. According to the survival outcome during hospitalization, the patients were divided into survival group and death group. According to OI, the patients were divided into mild-moderate group (OI > 100 mmHg, 1 mmHg = 0.133 kPa) and severe group (OI ≤ 100 mmHg). The expression of plasma miR-30b-5p was detected by real-time fluorescence quantitative reverse transcription-polymerase chain reaction (RT-PCR), and EVLWI was measured. The receiver operating characteristic (ROC) curve was drawn to analyze the value of plasma miR-30b-5p and EVLWI in predicting the death of patients with ARDS. Pearson correlation method was used to analyze the correlation between miR-30b-5p and EVLWI in ARDS patients with different prognosis during hospitalization. Results:120 patients with ARDS were enrolled in the analysis, with 42 patients in the death group, and 78 in the survival group; with 67 patients in the mild-moderate group, and 53 in the severe group. APACHE Ⅱ score in the death group was higher than that in the survival group, but there was no significant difference in gender, age, BMI, underlying diseases, etiology or baseline values of HR, RR, OI, or PaCO 2 between the two groups. The expression of plasma miR-30b-5p and EVLWI level in the death group were significantly higher than those in the survival group [miR-30b-5p (2 -ΔΔCt): 2.28±0.74 vs. 0.52±0.06, EVLWI (mL/kg): 15.38±4.60 vs. 10.24±2.15, both P < 0.01]. The expression of plasma miR-30b-5p, EVLWI and mortality during hospitalization in the severe group were significantly higher than those in the mild-moderate group [miR-30b-5p (2 -ΔΔCt): 2.05±0.65 vs. 0.93±0.17, EVLWI (mL/kg): 14.65±4.20 vs. 11.36±2.28, mortality during hospitalization: 58.5% (31/53) vs. 16.4% (11/67), all P < 0.01]. ROC curve analysis showed that the best cut-off value of plasma miR-30b-5p and EVLWI in predicting the death during hospitalization of ARDS patients were 1.62 and 13.28 mL/kg, respectively. Moreover, the area under ROC curve (AUC) of the combination of two parameters was significantly higher than that of the two alone (0.897 vs. 0.827, 0.785), with high sensitivity and specificity, 90.5% and 84.2%, respectively. Pearson correlation analysis showed that plasma miR-30b-5p in dead ARDS patients was significantly positively correlated with EVLWI ( r = 0.768, P < 0.01), but the correlation was not found in surviving patients ( r = 0.118, P > 0.05). Conclusion:The expression of plasma miR-30b-5p and EVLWI are related to the severity and prognosis of patients with ARDS, and the combination of the two has certain evaluation value for the prognosis of ARDS patients.

Objective:To investigate the value of serum microRNA-92a (miR-92a) and microRNA-146a (miR-146a) expression levels combined with lung ultrasound score (LUS) in predicting the severity and prognosis of acute respiratory distress syndrome (ARDS).Methods:116 patients with ARDS admitted to Danzhou People's Hospital from January 2017 to March 2020 were enrolled. On the day of admission, the expression levels of serum miR-92a and miR-146a were detected by real-time fluorescent quantitative reverse transcript-polymerase chain reaction (RT-PCR), and pulmonary ultrasound examination was performed in 12 lung regions, with the total score as LUS score. The difference of each index was analyzed among the ARDS patients with different 28-day prognosis (survival group and death group) and different severity [mild group: 200 mmHg < oxygenation index (OI) ≤ 300 mmHg (1 mmHg = 0.133 kPa), moderate group: 100 mmHg < OI≤200 mmHg, severe group: OI≤100 mmHg]. Multivariate Logistic regression was used to analyze the risk factors of death in patients with ARDS. Receiver operating characteristic (ROC) curve was drawn to analyze the value of miR-92a and miR-146a combined with LUS score in predicting the death of patients with ARDS.Results:116 ARDS patients were included, 39 cases in the death group, 77 cases in the survival group; 20 cases in the mild group, 38 cases in the moderate group and 58 cases in the severe group. The expression levels of serum miR-92a, miR-146a and LUS score in the death group were significantly higher than those in the survival group [miR-92a (2 -ΔΔCt): 3.75±1.64 vs. 2.10±0.78, miR-146a (2 -ΔΔCt): 1.93±0.72 vs. 0.76±0.20, LUS score: 25.80±4.75 vs. 13.40±3.60, all P < 0.01]. With the aggravation of ARDS patients, the expression levels of serum miR-92a and miR-146a and LUS score gradually increased ( F values were 8.115, 6.740 and 6.216 respectively, all P < 0.01). The expression levels of serum miR-92a, miR-146a and LUS score in severe group were significantly higher than those in the moderate group and mild group [miR-92a (2 -ΔΔCt): 3.65±1.62 vs. 2.87±1.16, 1.94±0.68; miR-146a (2 -ΔΔCt): 1.85±0.58 vs. 1.30±0.51, 0.68±0.17; LUS score: 24.15±4.65 vs. 18.60±4.20, 12.20±3.15, all P < 0.01]. Multivariate Logistic regression analysis showed that low OI [odds ratio ( OR) = 2.748, 95% confidence interval (95% CI) was 1.913-6.225, P = 0.024], high LUS score ( OR = 1.685, 95% CI was 1.183-2.758, P = 0.016), high expression levels of serum miR-92a ( OR = 2.560, 95% CI was 1.806-5.627, P < 0.001) and miR-146a ( OR = 1.984, 95% CI was 1.375-3.816, P = 0.008) were independent risk factors for the death of ARDS patients. ROC curve analysis showed that the area under ROC curve (AUC) of patients with ARDS predicted by miR-92a and miR-146a combined with LUS score was significantly higher than that predicted by the three alone (0.918 vs. 0.842, 0.825, 0.807, all P < 0.01), and the sensitivity (94.0%) and specificity (85.2%) were higher. Conclusion:The expression levels of serum miR-92a, miR-146a and LUS score are related to the severity and prognosis of the patients with ARDS, and the combination of the three indicators has better value in predicting the prognosis of the patients with ARDS.