Objective To study the value of multiphasic contrast-enhanced 3.0T MRI in the preoperative assessment of resectability in pancreatic cancer.Methods 38 patients with pancreatic cancer proved by operation and pathology were performed with multiphasic contrast-enhanced imaging at 3.0T MRI.The resectability of lesions was judged according to the status of vascular and adjacent organ involvement,lymphadenopathy and distant metastases on MRI images,which were compared with the results of operation.Results Of 38 pancreatic cancer,32 lesions located in the head,4 tumors in the body and 2 lesions in the tail of pancreas.MRI predicted that 1 9 tumors were resectable in which 1 7 lesions were successful resection,the accuracy of the positive predictive value for resectability was 89.5%.19 lesions were predicted to be unresectable by MRI,which were verified by surgery,the positive predictive value for un-resectability was 100%.The primary causes of unresectability contained peripancreatic main vessels involvement,liver metastasis, lymphadenopathy and peritoneal metastasis.Conclusion MRI multiphasic contrast-enhanced imaging has important value in preoper-ative resectability assessment of pancreatic cancer,which provides an useful reference for clinic to select appropriate treatment options.

Quantum dot is a new kind of nano-fluorescent material. It has unique optical properties and can be used for clinical research including cancer research, determination of metal content, microbe detection and developing of drug target. It will have the potential value in the study of disease mechanism, clinical diagnosis and treatment.

Objective To assess the value of the adjacent vessel sign (AVS)in differentiating malignant from benign lesions on breast MRI at 3.0 T.Methods Total 64 patients with 64 breast lesions including 35 malignant and 29 benign ones,underwent breast dynamic contrast enhanced MR scan.The 3D maximum intensity projection images were gotten and used to review the lesions.Sen-sitivity and specificity of the AVS were evaluated,and the reasons of the false positive and false negative lesions were also analyzed. Results The AVS differed significantly between benign and malignant lesions (P<0.001;positive-predictive-value:88.6%,sensi-tivity:88.6%,specificity:75.9%).Conclusion The adjacent vessel sign is significantly associated with malignancy.Thus,there is of great importance of this sign in differentiation of begnign and malignant lesions.

Objective To observe the therapeutic effect of antiangiogenesis on C6 glioma and to study the practical value of PWI in evaluating the early response of the tumor to the treatment.Methods C6 glioma cells were stereotactically implanted into SD rats intracranially.At the 15 day after tumor implantation,the recombinant human endostatin was administered or stereotactic radiosurgery was performed.Endostatin was injected subcutaneously at the dose of 5 mg?kg -1 ?d -1 ,10 mg?kg -1 ?d -1 ,and 20 mg?kg -1 ?d -1 for 7 days.Stereotactic radiosurgery was given once with the central radiation dose of 25Gy.MR PWI was performed to measure relative cerebral blood volume (rCBV) of the tumor and the normal brain before and 48 hours after treatment.Conventional MRI was performed to calculate tumor volume.Results The tumor volume was (429.0?36.7)mm 3,(305.7?32.8)mm 3,and (277.0?20.6)mm 3 in each endostatin treated group,and(390.0?33.8)mm 3 in SRS treated group,which were lower than that in control group(566.7?135.0)mm 3 (P=0.031).The rCBV in endostatin group was 1.57?0.12,1.30?0.12,and 1.24?0.08,respectively according to three different doses,which were lower than those before endostatin therapy with statistical significance (P

Objective To investigate the conventional MRI and perfusion weighted imaging (PWI) features of central neurocytoma(CNC), and to evaluate the potentiality of them in diagnosing accuracy. Methods Three patients with CNC proved pathologically were collected, 4 patients with ependymoma were as control group, with conventional MRI and perfusion weighted imaging were performed in all of them. MRI features were observed, and relative regional cerebral blood volume (rrCBV) were calculated.Results CNCs were isosignal on T_1WI, hyperintense on T_2WI, minimal enhancment. Ependymomas were hypointense or isosignal on T_1WI, slightly hyperintense or hyperintense on T_2WI and minimal enhancement. On PWI, CNCs were obviously high-perfusion, rrCBV was 11.2, but which was 2.1 in ependymoma, there was statistically signifcant difference between two groups(P

Objective To investigate the value of MR perfusion weighted imaging(PWI) features in typing meningioma preoperation.Methods MR perfusion weighted imaging was performed on 39 patients with pathologically proved meningioma.The relative regionalcerebral blood volume(rrCBV) and relative mean transit time(rMTT) were calculated.Results The rrCBV and rMTT of angioblastic meningiomas were 11.8 and 1.8,which were higher than that of the others subtype.The rrCBV of meningothelial meningiomas andtransitional meningiomas were 8.3,7.5 respectively,the rMTT of them were 1.5 and 1.3,there was statistically significant difference in rMTT between two groups,but no difference in rrCBV.The rrCBV of fibrous meningiomas was 4.0,which was lower than that of the others.Conclusion PWI is very useful in typing meninigioma preoperation.

Objective To analyze the imaging appearances of solitary fibrous tumors (SFT) of the lower limb.Methods The imaging manifestations of SFT of the lower limb proved with pathology in 2 patients were reported and the relevant literatures were reviewed.All patients underwent MR examination,and 1 received skeletal radiography.Results Both tumors were mainly located within the biceps muscle of thigh.MR demonstrated that the tumor appeared as a solitary round or oval well circumscribed mass,with inhomogeneous low to intermediate intensity signal on T1WI and heterogeneous low to high intensity signal on T2WI.Inhomogeneous enhancement was demonstrated on T1WI.Marked enhancement of solid components in the tumor was identified.No bone destruction was found on plain film.Conclusion There are some characteristics on the imaging of SFT of the lower extremity.MRI is the optimal imaging method for the diagnosis of this disease.

Objective To analyze MRI features of peripheral primitive neuroectodermal tumor (pPNET) in comparison with pathological findings. Methods The clinical manifestation, pathological features and the MRI appearances of 7 patients with pathologically proved pPNET were analyzed retrospectively. Results Among 7 patients, 2 patients located in intracalvarium, 2 in lower extremities, 1 in vertebral canal and extended outside of vertebral canal, 1 in cavitas pelvis and involved sacrum, and the rest 1 in the retroperitoneal space. The lesions in soft tissue manifested as iso-intensity on T1WI, slight hyper-intensity on T2WI with cystic degeneration and hemorrhage. Pseudo-capsule was seen in 1 patient. The solid parts of pPNET enhanced markedly after the contrast agent was injected. The adjacent bones were usually involved. pPNET in bone presented as osteolytic destruction of bone with large soft tissue mass. Immunohistochemical examination showed CD99 expression in all 7 patients, synaptophysin (Syn) expression in 4, Chromogranin (CgA) expression in 3, neuron specific enolase (NSE) expression in 2, vimentin (Vim) expression in 2 and EMA in 1 patient. Conclusion MRI has important reference value in diagnosis of pPNET, but final diagnosis still depends on the pathological and immunohistochemical examination.

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Objective To explore the value of multislice computed tomography (MSCT) in diagnosis of vascular rings associated airway abnormalities in children. Methods CT image data were retrospective analysis in 159 cases of vascular rings, including multiplanar reconstruction (MPR), maximum and minimum density project reconstructions. The relationship between the vascular rings and airway had been observed. Results Of 159 cases of vascular rings as-sociated with airway stenosis in 101 cases, the main airway stenosis in 79 cases, left main bronchial stenosis in 14 cas-es, right main bronchus in 8 cases, tracheal bridge in 14 cases, tracheal bronchial in 11 cases, symmetry bronchial in 2 cases. Conclusions Vascular ring often causes compression of airway narrow and dysplasia. MSCT can clearly display vascular rings and its relationship with airway, providing help for surgical and reasonable treatment.