Objective To investigate the correlation between apparent diffusion coefficient (ADC)of diffusion weighted imaging (DWI)and prognostic factors in rectal cancer.Methods 5 5 patients with rectal cancer were confirmed pathologically.Conventional pelvic MRI and DWI examination were performed,and the mean ADC values of tumor were measured preoperatively.The patients were divided into two groups with or without lymph node metastasis,and were also divided into four groups with negative,weakly positive,positive or strongly positive expression of EGFR in rectal cancer.The ADC values were calculated in each group,and the correlation of ADC values with the lymph node status and EGFR expression classification were analyzed.Results In 5 5 patients with colorectal cancer,there were 13 lesions with lymph node metastasis and the positive expression rate of EGFR was 67.2%.There were no significant difference in mean ADC value between the groups with and without lymph node metastasis (P=0.342).The number of lesions with negative,weakly positive,positive and strongly positive EGFR expression were 18,15,12 and 10.The difference in the mean ADC values among negative,weakly positive,positive and strongly positive expression groups of prognostic factor EGFR was not significantly different (P=0.412).There were also no correlations in the prognostic factors mentioned above (r=0.183 and -0.324,all P>0.05).Conclusion The ADC value can not be used to predict the prognosis and to provide more valu-able information for individualized therapy in patients with rectal carcinoma,which needs further studiy in the future.

Objective To investigate the correlation between apparent diffusion coefficient (ADC)value of MR diffusion weighted imaging (DWI)and Ki-67 expression in rectal cancer.Methods The data of 47 patients with rectal cancer confirmed by pathology were retrospectively analyzed.Pelvic MRI,rectum DWI and enhanced examination were performed preoperatively.According to the Ki-67 index,the patients were divided into A-D four Groups:Group A with Ki-67 <10% (-),Group B with Ki-67 10%-25%(+),Group C with Ki-67 26%-50%(++);and Group D Ki-67 > 50%(+++).ADC values were calculated in each group to analyze the correlation with the Ki-67 expression levels.Results The mean ADC value were (1.280 ± 0.200 )× 10 -3 mm2/s in Group A (13 cases),(1.044±0.046)×10 -3 mm2/s in Group B (14 cases),(0.987 ±0.256)×10 -3 mm2/s in Group C (9 cases), and (0.85 1±0.099)×10 -3 mm2/s in Group D (1 1 cases).The mean ADC values were significantly different in the different groups with different levels of Ki-67 expression (P =0.001).ADC value and Ki-67 expression were moderate negatively correlated (r = -0.577, P=0.000).Conclusion DWI and ADC measurement can evaluate indirectly the cell proliferation and prognosis of rectal tumor to some extent.

Objective To investigate the value of diffusion weighted imaging (DWI)in identification of different molecular sub-types for breast cancer classifications.Methods All patients with breast cancer were divided into four subtypes groups by immuno-histochemistry results including Luminal A subtype,Luminal B subtype,HER2-over expressing (HER2-OE)subtype,and triple negative breast cancer (TNBC),respectively.The means of maximum,average,and minimum ADC of the lesions in all patients were recorded.The analysis of ANOVA and least significant difference test (LSD-t )were used for the statistical evaluation.Results There were significant differences in maximum ADC,average ADC,and minimum ADC among Luminal A subtype (n=21),Lu-minal B subtype (n=22),HER2-OE subtype (n=1 7)and TNBC subtype (n=12)groups (P =0.025,0.039 and 0.041,respec-tively).However,paired comparison in mean of maximum ADC,average ADC and minimum ADC by LSD-t multiple comparisons among Luminal A,Luminal B,HER2-OE and TNBC respectively were not significantly different.Conclusion DWI may be difficult to discriminate the molecular subtypes of breast cancer classification before surgery or biopsy.

Objective To investigate the association of MRI features with HER-2 expression in non-mass-like breast carcinoma. Methods 74 patients with breast cancers diagnosed by pathology underwent MRI prior to surgery,and all lesions were non-mass-like enhancement on dynamic contrast-enhanced MRI.The expression of HER-2 in tumor tissue was detected by immunohistochemical staining.Chi-square test,Fisher’s exact test and spearman rank correlation were used to evaluate the correlations between the morphological characteristics, dynamic enhanced MR parameters,ADC value and HER-2 expression.Results The tumor size was correlated positively with the expression degree of HER-2 (r=0.341,P =0.003).The ADC value was also correlated positively with the positive expression degree of HER-2 (r=0.31 7,P =0.006).However,the time to peak was correlated negatively with that (r =-0.244,P =0.036).No significant correlations between the distribution/internal enhancement manner,the type of time signal intensity curve and HER-2 expression were found (all P >0.05).Conclusion Tumor size,time to peak and ADC value are correlated with the expression of HER-2 in non-mass-like breast carcinoma,which is helpful for the treatment plan and prognosis evaluation for this cancer.

Objective To determine the utility of single energy CT value and spectrum energy curve in identifying different cause of diffuse spleen enlargement.Methods 43 patients confirmed by either surgical pathology,aspiration biopsy or clinical comprehensive diagnosis and follow-up were assessed,including lymphoma with spleen infiltration(lymphoma group,n=18) and cirrhotic splenomegaly(liver cirrhosis group,n=25).All patients underwent upper abdomen CT scans in GSI mode and the GSI data were transferred to the Workstation AW 4.6 to acquire single energy CT value(40-140 keV,10 keV's interval) and spectrum energy curve of the spleen on the venous phase.All single energy CT values and the slope of curves were comparatively analyzed through independent-samples t test.The diagnostic efficiency were evaluated by ROC analysis.Results Under 40-140 keV energy range,single energy CT values were significantly lower in the lymphoma group than in the liver cirrhosis group(all P＜0.05).The spectrum energy curve were both types of decreasing.Under 40-90 keV,100-140 keV energy range,the slop of curves in the lymphoma group(2.42 ± 0.70,0.27± 0.08) were also significantly lower than in the liver cirrhosis group (3.11 ± 0.62,0.34± 0.07),respectively(all P ＜0.05).When the slope of curve under 40-90 keV energy range was selected as a diagnostic indicator,the area under the curve(AUC) would reach 0.77.If threshold value of 1.39 was taken,the sensitivity and specificity would be equal to 86 ％ and 64 ％,respectively.Conclusion Single energy CT value and spectrum energy curve are helpful for differentiation of lymphoma with spleen infiltration from cirrhotic splenomegaly.

Objective To explore the value of the molecular probe USPIO-PEG-sLeX on nasopharyngeal carcinoma xenograft in nude mice.Methods The USPIO nanoparticles was synthesized by physical deposition method,and which was modified by PEG to synthesize USPIO-PEG-sLeX .The nude mice of nasopharyngeal carcinoma xenograft were divided into experimental and control groups.USPIO-PEG-sLeX and USPIO-PEG were injected into nude mice of experimental and control groups by caudal vein,respectively.MR T2 mapping imaging was scanned before and after the injection,and analyzed the changes of T2 values between experimental and control groups. Results USPIO-PEG-sLeX had a good representation.The non-enhanced T2 values between control and experimental group had no statistical significance (P >0.05).However,T2 values of the mice in two groups before and after injections were statistically significant (P <0.05);and T2 values of experimental group were much lower than that of the control group after the injection,additionally,the difference of enhanced rate between the two groups was statistically significant (P <0.05).Conclusion USPIO-PEG-sLeX magnetic nanoparticles is potential to be a targeted contrast agent to ELAM-1 expression of nasopharyngeal carcinoma,and can be valuable in non-invasive dynamic monitoring the expression of ELAM-1.

Objective To analyze the MRI findings of pure mucinous breast carcinoma and to investigate the causes of misdiagnosis.Methods MRI findings of 1 3 patients with pure mucinous breast carcinoma were analyzed retrospectively.All patients were verified by surgery and histopathology.Results All the 13 cases were presented as a mass,among which 12 cases (92.3%)had lobular contour and 1 (7.7%) had irregular shape.11 cases (84.6%)showed low or iso-signal intensity and 2 (15.4%)showed heterogeneous iso or high intensity on T1WI.All the 13 cases showed high signal intensity on fat suppression T2WI,and 5 cases(38.5%)showed low signal fiber separation inside. 5 cases (38.5%)showed homogeneous high signal intensity and 8 cases (61.5%)showed heterogeneous high signal intensity on diffusion weighted imaging(DWI)and apparent diffusion coefficient(ADC)map,the ADC value was (2.002±0.478)× 10-3mm2/s.11 cases (84.6%)showed rim enhancement,among which 8(61.5%)showed persistent enhancement and 2 (15.4%)showed heterogeneous enhancement.Time-signal intensity cure(TIC)of 11 cases(84.6%)were monophasic or biphasic and 2 cases(15.4%0)were wash-out type. 5 cases(38.5%)were misdiagnosed on preoperative MRI.Conclusion There are several MRI features in pure mucinous breast carcinoma,such as lobular contour,high signal intensity on DWI and ADC map,persistent enhancement and monophasic or biphasic on TIC.Comprehending these MRI features is the key to reduce misdiagnosis.