Objective To evaluate the reproducibility of the three-dimensional volume measurement and two-dimensional measurement of pulmonary nodule volume with 64-detector computed tomography.Methods Thirty-three patients with pulmonary nodule who underwent the examination with 64-detector spiral CT(Lightspeed VCT,GE) were included,in whom sixty solid nodules with the diameter less than 3 cm were found.There were 18 women and 15 men.CT images were analysed by two radiologists,respectively,the volumes of pulmonary nodules were measured with ALA software continuously,and two-dimensional measurements which were separated a month apart were also done in the GE AW4.2 workstation independently.Intra-and inter-reader agreement were determined by using Bland and Altman method and the Spearman correlation coefficients,the variability between three-dimensional measurements and two-dimensional ones were identified.Results 57 nodules in 60 were successfully segmented and 3 were segmented incorrectly or unsuccessfully,the ratio of successful segmentation was 95%.Three-dimensional measurements between two readers were highly correlated with r of 0.998,and the r was 0.974 in the two-dimensional measurements.The difference between the two correlation coefficients was significant.The three-dimensional measurements between two readers had completely agreed with each other for nodules that of the diameter

Objective To assess the ability of pixel-based quantitative evaluation of CT values in differentiating benign and malignant cystic-solid ovarian tumors.Methods CT images of 41 cystic-solid ovarian lesions from 39 patients were reviewed,with 27 benign and 14 malignant confirmed by post-operation pathology or follow-up.Regions of interest (ROIs) were drawn along edges of tumors on all slices of contrast-enhanced images with ImageJ software.CT values of each pixel were extracted.CT values of 20,25,30,35 and 40 HU were used respectively as the threshold to divide cystic and solid components.Solid proportion,the mean and median CT values of solid component were calculated and compared between benign and malignant groups.Results Mean CT values of solid components were all higher in malignant than in benign ovarian masses under all the threshold values (P<0.05).For median CT values, the same trend existed under the threshold of 20,25,35 and 40 HU (P<0.05).For the solid proportion,difference was found only under the 40 HU threshold, with lower value in malignant group (0.67±0.25) than in benign group (0.47±0.31).ROC curves were drawn to differentiate benign and malignant lesions.The highest AUC was obtained by using the mean CT value of solid components defined by 40 HU threshold (AUC=0.735).Conclusion Pixel-based quantitative evaluation on CT images could help to define cystic and solid components of ovarian masses, with 40 HU to be an optimal threshold.Cystic-to-solid proportion and CT value of solid components derived from whole lesion can help to differentiate benign or malignant lesions.

Purpose To explore the correlation between quantitative parameters from intravoxel incoherent motion (IVIM) with prognostic factors of rectal adenocarcinoma.Materials and Methods Eighty-six patients with rectal adenocarcinoma who were underwent surgery without neoadjuvant therapy in our hospital between September 2015 and July 2016 were selected in this retrospective study.The image data included multiple b-values diffusion weighted imaging (DWI) examination and the corresponding D,D* and f values of the lesions.Relationships between the quantitative parameters and tumor pathology indexes including histological differentiation grade,tumor T/N stage,lymphangiovascular invasion state,the expression level of epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor-2 (Her-2) were assessed.Results The average D values of different differentiation degree (high,middle and low) of rectal adenocarcinoma were (0.541±0.093)×10 3mm2/s,(0.490±0.156)×10-3mm2/s and (0.342 ± 0.147)× 10-3 mm2/s,and the difference was statistically significant (P＜0.05).TheD values were significantly different between the lymphangiovascular invasion and non invasion state [(0.511 ±0.154)× 10-3 mm2/s vs (0.387±0.130)×10-3 mm2/s,P＜0.05)].However,there were no significant differences in the mean D,D* and f values among different tumor T/N stage (P＞0.05).The average f value of EGFR or Her-2 high expression group was higher than that of low expression group (0.379±0.076 vs 0.298±0.099,P＜0.01;0.356±0.097 vs 0.298±0.098,P＜0.05,respectively).Conclusion Quantitative parameters of IVIM in rectal adenocarci-noma can be used as noninvasive imaging biomarkers to predict the biologic behavior of tumor and the prognosis of the patients.

Objective To analyze the detection of lymph node in normal human and patients with gastric cancer by helical CT.Methods Helical CT examinations of upper abdomen were performed in 88 normal person and 106 patients with gastric cancer.The detection of lymph nodes were analyzed.Results There was obvious difference in the detecting rate of lymph node by helical CT between normal and gastric cancer cases.The total detecting rate of lymph nodes by helical CT was 39.7%,while for metastatic nodes was 69.2%.Conclusion The density increase of lymph node is important to its CT detecting rate.CT detecting rate of lymph node has significance correlation to gastric cancer.High attention much be paid to detecting lymph node of lymphatic drainage area of gastric cancer.

Objective To evaluate the usefulness of diffusion-weighted MR combined with routine T2 WI in finding the possible residual foci in uterine cervical cancers after radical chemo-radiation therapy.Methods This was a retrospective study including 25 consecutive cervical cancer patients who received hysterectomy after radical chemo-radiation therapy.All of them underwent MR examinations post-chemoradiation and just before operation.Images of T2 WI alone and those of T2 WI combining DWI were evaluated respectively by 2 senior radiologists,in order to decide whether there were residual tumors.ADC values were also measured.Taking the post-operation pathological results as the gold standard,the accuracies,sensitivities and specificities of T2 WI alone,T2 WI combining DWI,and ADC values were all calculated.Results In those 25 patients,9 were found with foci of residual cancer in operative pathology,while no cancer cells were found in the other 1 6 patients.The accuracy,sensitivity and specificity in finding the positive residual cancer using T2 WI alone were 56.0%,77.8% and 43.8%,comparing with 72.0%,66.7% and 75.0% in T2 WI combining DWI.The accuracy and specificity increased with statistical significance after combining DWI (P =0.01 6 for accuracy,P =0.031 for specificity),while the sensitivity decreased but did not reach statistically significant level (P =0.099).No difference in ADC values was found.Conclusion DWI can be used as a supplementary sequence in finding the existence of residual tumors of cervical cancer after radical chemo-radiation therapy.Routine T2 WI combing DWI increased the specificity and accuracy,but still facing the risk of decreasing sensitivity.

Objective To investigate the feasibility of ADC values that derived from MR DWI with multiple b values in reflecting the amplitude of enhancement and degree of differentiation in cervical squamous cell carcinomas on 3.0T MR scanner.Methods DWI and multiple phase contrast enhanced MRI images of 31 patients with pathologically diagnosed cervical squamous cell carcinomas were retrospectively analyzed.All ADC values in different b values and the amplitude of signal intensity enhancement were measured in various areas of tumors.Correlations of differences of ADCs in high and low b values with early and late enhancement,and the relationship of ADC and differences of ADCs with pathologically tumor differentiation grades were analyzed.Results ADC value in high and low enhanced areas of cervical cancer was inversely related with different b values.Differences of ADCs between low b value (200 s/mm2) and high b values (800,1 000,1 200,1 400 s/mm2) had weak positive correlation with early enhancement (r=0.315-0.339,all P＜0.05).While b=800 s/mm2 and 1 000 s/mm2,ADCs in highly enhanced areas of tumor were significantly lower in well-differentiated cancer lesions compared with those of poorly differentiated cancer lesions.There was no statistically significant of ADC value in other b values,and also of differences of ADCs in all b values in different differentiation foci (all P＞0.05).No differences were found in ADC values under other b values in various degree of differentiation foci,nor in differences of ADCs in all b values (all P＞0.05).Conclusion Combination of multiple b values of DWI may have the potential to reflect blood supply and tumor differentiation grades in cervical squamous cell carcinomas,while low b value of 200 s/mm2 and high b values of 800 s/mm2 and 1 000 s/mm2 will be the preferable choice on 3.0T MR scanner.

Objective To evaluate the efficacy of high resolution MR T2WI combined with DWI in evaluation of pathological complete response after neoadjuvant therapy in rectal cancer.Methods Totally 364 patients with locally advanced rectal cancer who recieved neoadjuvant therapy and radical surgery,underwent MR scanning before and after neoadjuvant therapy,were enrolled in this study.The diagnostic efficacy of high resolution MR T2WI and high resolution MR T2WI combined with DWI in evaluation on pathological complete response after neoadjuvant therapy in rectal cancer were compared.Results Finally 49 cases were demonstrated pathologic complete response.Accuracy,sensitivity,specificity,positive predictive value and negative predictive value of high resolution MR T2WI and high resolution MR T2WI combined with DWI in predicting on pathological complete response after neoadjuvant therapy were 82.69％ (301/364),40.82％ (20/49),89.21％ (281/315),37.04％ (20/54),90.65％ (281/310)and 87.36％ (318/364),65.31％ (32/49),90.79％ (286/315),52.46％ (32/61),94.39％ (286/303),respectively.Sensitivity had statiatical significant difference between two methods (x2 =4.96,P=0.03).Conclusion Compared with high-resolution T2WI,the combination of DWI and high-resolution T2WI can improve the diagnostic efficacy in evaluation of pathologic complete response of locally advanced rectal cancer.

Objective To explore the risk factors for early interhepatic recurrence and metastasis of hepatocellular carcinoma (HCC)on CT imaging before treatment.Methods 1 1 5 patients suffered from HCC from July 2003 to January 2009 were retrospec-tively enrolled for reviewing their clinical characteristics and CT signs.The status of metastasis and/or recurrence was followed reg-ularly.Signs on pre-treatment enhanced CT images were measured and analyzed.Analysis of variance and independent sampler t test were applied for Univariate survival analysis.Then multivariate analysis was carried out by the Logistic regression,Lon rank meth-od,and p-value < 0.05 was defined to be statistically significant.Results The early interhepatic recurrence and metastasis rate of the study group was 58.26%.With univariate analysis,tumor size,location,extent,capsule,satellite nodule,vascular invasion, AVM and necrosis were the risk factors for early recurrence and metastasis of HCC on pre-treatment enhanced CT imaging (P<0.05).Multi-variable Logistic regression analysis showed that tumor size,satellite nodule,vascular invasion capsule and were independently sig-nificant CT signs for early interhepatic recurrence and metastasis of HCC (P =0.031,0.005、0.037、0.048).Conclusion Pre-treat-ment enhanced CT imaging with HCC was closely related to early interhepatic recurrence and metastasis of the tumor.A tumor of larger size,with satellite nodules,without complete capsule and vascular invasion on CT may predict a tendency to early interhepatic recurrence and metastasis of HCC.

Purpose To compare the CT features of hepatic metastases of gastro-entero-pancreatic adenocarcinomas with and without neuroendocrine differentiation [NED(+) and NED(-)] and to explore the value of CT features in differentiation of the two groups.Material and Methods From January 2009 to December 2015,abdominal CT scans of 17 pathologically proved cases of NED(+) gastro-entero-pancreatic adenocarcinomas with hepatic metastases and 34 pathologically proved cases of NED(-) hepatic metastases with sex,age and primary site matched were retrospectively reviewed.CT features including hepatic metastases number,size,distribution,shape and enhancement were assessed,as well as presence of lymphadenopathy or ascites.Differences of CT features between the two groups were analyzed.Results Compared with NED(-) group,hepatic metastases of NED(+) group more frequently demonstrated a peripheral enhancement on artery phase (94.1％ vs.44.1％,P＜0.05),and more washout on portal venous phase (41.2％ vs.5.9％,P＜0.05),while hepatic metastases of NED(--) group showed more plateau type (91.2％ vs.58.8％).There was no significant difference of other findings between the two groups (P＞0.05).Logistic regression revealed that enhancement area in hepatic artery phase and enhancement changes in portal venous phase were independent factors for differential diagnosis (P＜0.05).The area under the ROC curve of combining the two features was 0.811 (P＜0.05).Conclusion There are some different CT enhancement features between NED(+) and NED(-) hepatic metastases of gastro-entero-pancreatic adenocarcinomas,which are helpful in differential diagnosis.

Objective To assess response of rectal carcinoma to preoperative chemoradiation therapy(CRT)using DWI and tumor ADC values,and to investigate the value of ADC in predicting and monitoring therapeutic effect of CRT.Methods Twenty-six patients with primary rectal carcinoma undergoing preoperative CRT were recruited to the study.DWI was performed on a 1.5 T MR scanner in all patients at the time point of pre-therapy,the end of the 1st,2nd week of therapy and pre-operation,respectively.ADC values of the tumors were calculated on the workstation.Randomized block design was applied to analyze change in ADCs following treatment Results All patients were divided into T-downstaging group(n=12)and T-non-downstaging group(n=14).In T-downstaging group,the mean tumor ADC values were(1.10±0.13)×10~(-3),(1.32±0.19)×10~(-3),(1.35±0.13)×10~(-3),(1.32±1.00)×10~(-3) mm~2/s at the time point of pretreatment,week 1,week 2,pre-operation,respectively(F=16.420,P＜0.01).The mean tumor ADC value in T-non-downstaging had a slight increase from(1.16±0.16)×10~(-3) mm~2/s to(1.23±0.13)×10~(-3) mm~2/s at the time of week 1(P＞0.05).The ADC value in T-non-downstaging group continuously increased to(1.30±0.16)×10~(-3) mm~2/s at the end of the 2nd week of CRT(F=5.023,P＜0.01)and appeared statistical difference.The evolution of tumor ADC values in the two groups was significantly different.Early increases in tumor ADC were observed in T-downstaging group.Regarding the increase percentage of ADC value at 1st week as a diagnostic marker of tumor downstaging,when it was set as 11.6%,the sensitivity,specificity,positive predictive value and negative predictive value is 75.0%,78.6%,75.0% and 78.6% respectively,the area under curve(Az)was 0.774(95% confidence interval:0.583 to 0.964).Conclusions An early significant increase of mean tumor ADC value in rectal carcinoma has a potential to predict therapeutic effect of CRT.One week after beginning CRT is an early time point to monitor therapy efficacy.