ObjectiveTo investigate the effect of different reference vessel groups on CT perfusion in patients with nasopharyngeal carcinoma (NPC) after radiation therapy,and explore the feasibility of substitution of reference vessel.MethodsThirty patients with NPC after radiation therapy were divide into two groups,recurrence group ( n =19) and fibrosis group ( n =11 ).All patients underwent CT perfusion scans,and the CT parameters were calculated with different arterial input and vein output in order to study their differences.The vessels were internal carotid artery-internal jugular vein( ICA-IJV group),external carotid artery-retomandibular vein (ECA-RTV group)and external carotid artery-internal jugular vein( ECAIJV group) respectively.The differences of the CT parameters between local recurrence group and fibrosis group were compared among the various vessel groups by rank sum test.With the help of receiver operating characteristic curve (ROC),the diagnostic efficiencies were compared by the area under the ROC curve (AUC).ResultsIn ICA-IJV group,ECA-RTV group and ECA-IJV group,bloood flow(BF) of local recurrence group were 201.88,439.59,252.23 ml · min-1 · 100 g-1,while BF of fibrosis group were 98.96,180.50,106.55 ml · min-1 · 100 g-1.Blood volume (BV) of local recurrence group were 6.71,12.39,6.70 ml/l00 g,while BV of fibrosis group were 2.35,4.76,2.95 ml/100 g.Mean transit time (MTT) of local recurrence group were 1.66,1.50,1.56 s,while MTT of fibrosis group were 2.13,1.96,1.79 s.Permeability surface (PS) of local recurrence group were 19.31,36.39,15.22 ml · min- 1 ·100 g-1,while they were 16.58,29.08 ,16.63 ml · min-1 · 100 g-1 in the fibrosis group.The differencesof BF and BV between the local recurrence group and fibrosis group were statistically significant in each vessel group (P ＜ 0.05 ) but MTT and PS showed no significant difference( P ＞ 0.05 ).In ICA-IJV group,the AUC of BF,BV,MTT,PS were 0.909,0.947,0.677,0.703,respectively.BF,BV,MTT,PS in ECA-RTV group were 0.938,0.967,0.648,0.679 respectively,and those in ECA-IJV group were 0.861,0.890,0.641,0.656 respectively.However,AUC of BF and BV of three groups all had significant difference ( P ＜ 0.01 ).ConclusionsBoth BF and BV values calculated by three pairs of reference vessels had enough diagnosis efficiency for local recurrence and fibrosis,so all of the three groups of vessels may substitute each other in CT perfusion.

Objective To measure hepatic blood flow of the normal liver and cirrhotic liver with hepatocellular carcinoma using multi-slice spiral CT(MSCT),and to evaluate the feasibility of the quantitative judgement of classification of liver cirrhosis with CT perfusion imaging.Methods CT dynamic perfusion imaging was performed in 53 subjects,including 32 patients of liver cirrhosis with hepatocellular carcinoma and 21 patients without liver disease(control subjects).The patients of liver cirrhosis with hepatocellular carcinoma were divided into three groups by CT morphologic classification :17 were classified as light liver cirrhosis group,8 as moderate group,7 as severe group.The parameters of CT perfusion included blood flow(BF),blood volume(BV),mean transit time(MTT),hepatic arterial fraction(HAF)and impulse residue function to(IRF To).The parameters were analyzed by the CT perfusion 3 software package(GE)with deconvolution method,and the correlation of the CT morphologic classification of liver cirrhosis with Child-Pugh functional classification was further evaluated.100 g-1,(17.81±6.59)ml/100 g,(9.52±3.08)s,0.20±0.08 and(4.38±2.35)s,respectively,while 0.27±0. 09 and (4. 14±2. 16)s, respectively. The mean BF, BV and HAF between normal livers and liver cirrhosis were statistically significant (P＜0. 05), and there were significant statistical differences in BF, BV and HAF among light, moderate and severe liver cirrhosis (P＜0. 05). The CT morphologic classification of liver cirrhosis was correlated positively with Child-Pugh classification (r=0. 935, P=0. 001 ). Conclusions Hepatic perfusion with MSCT can reflect the change of blood flow of cirrhotic liver, and MSCT perfusion can quantitatively evaluate the liver cirrhosis degree of patients with hepatocellular carcinoma.

Endothelial leukocyte adhesion molecule -1 ( ELAM -1 ) is a member of the cell adhesion molecules,which plays a great role in the distant metastasis of tumor in ligand interactions between sLe (x)and sLe(a).Recently,it becomes a new research hotspot on applying ELAM -1 in targeted cancer therapy.Many studies results show that by regulation of ELAM -1 in biological effects ,such as ELAM-1 and ligand inhibitors , monoclonal antibody ,targeting gene ,and other mediates of the path of blocking therapy ,thereby inhibiting or bloc-king tumor distant metastasis ,so as to achieve the purpose of tumor therapy and improve the prognosis .Therefore , ELAM-1 is expected to exert a critical role in the tumor targeted therapy .In this paper ,the application value of ELAM-1 in tumor related targeted therapy is reviewed .

Objective To study the value of CT perfusion in differential diagnosis of local recur and local radiofibrosis of nasopharyngeal carcinoma(NPC) at pre-and post-radiotherapy.Methods Dynamic CT scan was performed in 71 objectives: 14 in local recur group,22 in radiofibrosis group,15 in pre-radiotherapy NPC group and 20 in control group,the time-density curve(TDC) and the data of perfusion parameters were recorded and analyzed statistically.Results The TDC feature between local recur group,pre-radiotherapy NPC group and radiofibrosis group,control group had difference.The average of blood flow(BF) had significant differences by two by two comparison in four groups(P

0.05).Conclusion The parameters of CT perfusion can be regarded as a surrogate index of tumor angiogenic activity pre-and post-radiotherapy in nasopharyngeal carcinoma.

Objective To investigate the diagnostic value of DWI on nasopharyngeal neoplasm recurrence and fibrotic lesions after radiotherapy.Methods A retrospective analysis of pathologically confirmed nasopharyngeal neoplasm was performed in 39 patients with recurrent patients ( recurrence group ) confirmed by biopsy or MRI follow-up and 51 patients with confirmed localized fibrosis (fibrosis group) after radiotherapy.All patients underwent DWI , non-enhanced and enhanced MR scan.DWI findings and ADC values of the lesions in two groups of patients were observed and measured , then compared by using independent samples t test.Diagnostic performance of routine MRI and DWI in the diagnosis of nasopharyngeal neoplasm recurrence after radiotherapy was calculated by using ROC analysis and the differences of both of them were analyzed by using Z test.Results DWI of 39 recurrent patients showed hyper-intensity signal and ADC map showed hypo-intensity signal appearance.Overall signal of DWI in 51 recurrent patients is lower than that in recurrent group , in which ADC maps of 36 cases showed iso-intensity or moderately hypo-intensity signal appearance and the remaining 15 cases showed moderate hyper-intensity signal appearance.The ADC values of recurrent group and fibrotic group were (0.753 ±0.127) × 10 -3 mm2/s, and ( 1.233 ± 0.310 ) ×10 -3 mm2/s, respectively.The difference was statistically significant ( t=-9.118, P<0.05).On the ROC curve, the sensitivity of ADC for the diagnosis of tumor recurrence was 87.18%(34/39), specificity 94.12%(48/51) and area under the ROC curve 0.968 with the ADC cutoff value of 0.887 ×10 -3 mm2/s.The sensitivity of routine MRI was 71.79% ( 28/39 ) , the specificity 74.51% ( 38/51 ) and the area under the ROC curve was 0.732 for the diagnosis of tumor recurrence.The difference of area under the curve between them was statistically significant ( Z=4.583, P<0.01).Conclusion DWI can help tumor detection and diagnosis of recurrent nasopharyngeal neoplasm and has a higher diagnostic performance compared with routine MRI.

Objective To study 18F-deoxyglueose positron emission tomography computed tomo graphy(18 FDG PET-CT) in the diagnosis of cervical lymph node(LN) metastasis from rabbit nasopharyngeal VX2 carcinoma.Methods Nasopharyngeal VX2 carcinoma model using 30 rabbits was established. 18 FDG PET-CT,MRI and pathological diagnosis were performed and compared.ResultsFifty-three cervi cal LNs were picked up from resected specimens of 30 rabbits with nasopharyngeal VX2 carcinoma.There were 42 pathologically confirmed positive LNs.Positivity rate was significantly correlated with the volume and the shortest diameter of the LNs (r = 9.18,P =0.007 ; r = 2.77,P = 0.008).The diagnostic sensitivity of PET-CT was 96% (24/25) and 29% (5/17) for LNs with volume >0.5 cm3 and ≤0.5 cm3 ,83% (25/30) and 33% (4/12) for LNs with the shortest diameter ≥0.5 cm and < 0.5 cm,respectively.The diagnostic sensitivity,specificity and accuracy of PET-CT was 69% (29/42) ,100% (11/11) and 95% (40/42) ,com paring with 60% (25/42) ,91% (10/11) and 83% (35/42) of MRl,respectively.The volume measured by PET-CT images was not significantly different from the pathologically measured volume (t =-1.23,P = 0.233) ,while the volume measured by MRI was significantly different from the pathologically measured vol ume (t =-3.99,P = 0.001).Conclusions The sensitivity,specificity and accuracy of PET-CT are better than those of MRl,especially for the cervical lymph nodes with volume >0.5 cm3 or the shortest diameter ≤ 0.5 cm.PET-CT also can be used to detect the smaller metastatic lymph nodes,though the false negative rate is higher.

Objective To explore the diagnostic performance of susceptibility weighted imaging (SWI) in distinguishing malignant from benign parotid lesions.Methods We prospectively evaluated preoperative SWI findings of 41 patients with 12 malignant and 29 benign parotid lesions by surgical pathology, and explore the intravenous distribution, the largest diameter of veins (dv-max), the number of veins per unit area (N/Svein) and the graduation of intratumoral susceptibility signal intensity (ITSS).The parameters was analyzed by Chi-square test, Independent t-test, Mann-Whitney U rank test and receiver operating characteristics (ROC) curves with SPSS 16.0 software.Results (1) For intravenous distribution, the benign ones mainly distributed around peripheral areas, accounting for 89.7％ (26/29), while the malignant ones were centrally distributed, making up 10/12.There were significant difference (x2=20.882, P=0.000) between benign and malignant ones.(2) The largest diameter of veins (dv-max) of benign and malignant lesions were (1.1±0.5) mm and (2.5 ± 1.0)mm respectively.There were significant difference (t=4.633, P=0.000) between benign and malignant ones.(3) The N/Svein of benign lesions were (0.80±0.92) per cm2, while that of malignant ones are (1.07±0.69) per cm2.The N/Svein (t=0.9143, P=0.367) was statistically insignificant.(4) For the graduation of ITSS,among benign lesions, there were 3 cases of grade 0, 22 cases of grade 1, 2 cases of grade 2 and 2 cases of grade 3.Meanwhile, there were 2 cases of grade 1, 5 cases of grade 2 and 5 cases of grade 3 among malignant lesions.When the Youden index reached the highest point, the optimal diagnostic threshold of dv-max and ITSS values were 1.75 mm and 1.5 mm, the corresponding area under the ROC curve (AUC) were 0.924 and 0.856 respectively.The sensitivity of d and ITSS ondiagnosis were 10/12 and 10/12, and the specificity of that were 96.6％ and 86.2％ respectively.The table shows that the sensitivity and specificity of intravenous distribution in diagnosis of malignant lesions are 10/12 and 89.7％.Conclusions The results provided evidence that SWI may be helpful in distinguishing malignant from benign parotid lesions, and it is worth to be generalized in clinical medicine.

Objective To evaluate the value of differential diagnosis between benign and malignant thyroid lesions by susceptibility weighted imaging(SWI).Methods 53 patients with 20 malignant thyroid lesions and 71 benign thyroid lesions confirmed by surgery and pathology were analyzed retrospectively.All cases received conventional MRI and SWI preoperatively.Location,volume,SWI parameters including signal to noise ratio(SNR),contrast noise ratio(CNR)and intratumor susceptibility hypointensity (ITSHIA)datas in benign and malignant lesions were compared and analyzed.Results There was no statistical significance between benign and malignant thyroid lesions in the location,volume,SNR and CNR(χ2 or t =0.014,0.286,0.927,1.169;P =0.907,0.778,0.368,0.259 respectively).The maximum diameter (1.90 mm±0.32 mm),degree of maximum diameter(1.33±0.47),frequence(1.40±0.20)and area ratio(1.09±0.28)for benign thyroid lesions were less than those for malignant lesions(3.39 mm±0.79 mm,2.25±0.44,1.40±0.68,1.70±0.47)respectively (t or Z =12.629,5.788,3.41 5,5.795;P =0.000,0.000,0.001,0.000).Conclusion SWI semiquantitative assessment of pathlogical vascularity is useful in differential diagnosis of benign and malignant thyroid lesions.

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.