Objective To quantify the perfusion parameters of normal pancreas and pancreatic carcinoma with three-dimension (3D) fast spoiled gradient echo dynamic contrast enhanced (DCE) MRI on 3.0T MR system, and to assess the value of 3D DCE-MRI in the diagnosis of pancreatic carcinoma. Methods Thirty-four patients with pathology verified pancreatic carcinoma and 31 control subjects with normal pancreas (without pancreatic diseases) underwent DCE-MRI with 3D LAVA sequence of ten phases. The data were processed on ADW 4.2 workstation. The perfusion parameters of the head, body and tail of normal pancreas, together with lesion and non-lesion area of pancreatic carcinoma were measured and statistically analyzed, including signal enhancement ratio at 30 s after injection (SER_(30)), signal enhancement ratio at 90 s after injection(SER_(90)), positive enhancement integral (PEI), time to peak (TTP) and maximum slope of increase (MSI). Results There was no significant perfusion difference among head, body or tail of normal pancreas (P>0.05). The difference of SER_(30), PEI, TTP and MSI between lesion and non-lesion region of carcinous pancreas was significant (P<0.05). The TTP between normal pancreas and the non-lesion region of carcinous pancreas was significantly different (P<0.05). Conclusion Normal pancreas has no regional perfusion difference. The data from DCE-MRI provide reliable information for the diagnosis of pancreatic cancer, and for the assessment of the invasion of pancreatic carcinoma. The difference in TTP between the normal pancreas and non-lesion region of carcinous pancreas suggest the existing of potential lesions.

Objective To investigate the alteration of the default-mode network (DMN) in the patients with minimal hepatic encephalopathy (MHE) using resting functional MRI, and to explore its underlying clinical significance. Methods Fourteen MHE patients and 14 age-matched normal controls underwent standard resting state functional MRI scan. The components representing DMN were picked out after separation of independent component analysis. One and two sample t-tests were used to observe the changes of DMN in the patients in contrast to the controls. Results Typically spatial distributions of the DMN were found in both MHE patients and controls. Comparison results revealed that there was significantly reduced functional connectivity in the left posterior cingulate cortex, bilateral anterior cingulate cortex, bilateral medial prefrontal cortex, left parahippocampal cortex in MHE patients, while functional connectivity increased in the right precuneus. Conclusion Resting state functional MRI can be used to observe DMN changes in MHE patients. In MHE patients, there is reduced DMN activation in the widespread regions, while the activation of right precuneus increases.

Objective To evaluate the therapeutic effect of intramyocardial controlled releasing base fibroblast growth factor (b-FGF) stent combined with transplanting bone marrow-derived mesenchymal stem cells (BM-MSCs) in porcine acute myocardial infarction (AMI) models. Methods Eighteen porcines were divided into three groups (each n=6):transmyocardial revascularization (TMR)+naked stent (control group), TMR+b-FGF stent (b-FGF group) and TMR+b-FGF stent+BM-MSCs (b-FGF+BM-MSCs group). Acute myocardial infarction models were induced by ligating the left anterior descending artery in 18 porcine. In the control and b-FGF group, naked stents, b-FGF stents and b-FGF stent+BM-MSCs were implanted into TMR channels in the infarct and border zone. ~(99m)Tc-methoxyisobutylisonitrile (MIBI) myocardial perfusion imaging were performed to evaluate changes in myocardial blood flow, and echocardiography and immunohistochemical studies were also performed. Results After 6 weeks, the quality of myocardial infarction, fractional shortening, neovascular density in b-FGF and b-FGF stent+BM-MSCs group were higher than those of control gruop (P<0.05), and in b-FGF stent+BM-MSCs group was higher than those in b-FGF group (P<0.05). Conclusion BM-MSCs combined with controlled releasing intramyocardial b-FGF stent can improve the flow of myocardial infarction area, promote angiogenesis and heart function, and the therapeutic effect which can be evaluated with myocardial SPECT imaging.

Objective To explore the relationship between the quantitative parameter in transrectal power Doppler ultrasonography (PDUS) and angiogenesis of prostate nodules in pathology. Methods PDUS and the analytic software of color flow were used, and peak vascularization indexs (PVIs) of 94 prostate nodules in 73 patients were recorded. The biopsy specimen was stained with CD34 antibody, and the microvessel density (MVD) was calculated. The correlation between PVI and MVD was statistically analyzed. Results PVI and MVD of the malignant nodules, in both transition zone (TZ) and peripheral zone (PZ), were significantly higher than those of the benign nodules, respectively (P＜0.05). There was positive correlation between PVI and MVD of the malignant nodules (rTZ=0.76;rPZ=0.79), but no correlation between PVI and MVD was found in TZ of benign nodules (r=0.18), while there was correlation between PVI and MVD in PZ (r=0.44). In TZ, the sensitivity and speciality of differentiation malignant nodules from benign nodules were 78.57% and 80.77%, respectively, and in PZ they were 62.07% and 91.00%, respectively. Conclusion As a quantitative parameter in PDUS, PVI can indirectly reflect the angiogenesis of prostate cancerous nodules, providing a new method for differentiation malignant nodules from benign nodules.

Velocity vector imaging (VVI) is a promising and relatively new noninvasive method of assessing wall movement and flexible features of vessels,being able to qualitatively, quantitatively, accurately and intuitively assess mechanical characteristics of vascular wall movement. VVI can reflect changes of characteristics of flexibility and movement of carotid artery in early atherosclerosis and plaque rotation angle. It provides a new way for the study of unstable plaque. The research and current status of clinical application of VVI were reviewed in this article.

Objective To compare two effective preparation methods for paclitaxel-loaded lipid microbubbles, and to evaluate the physiochemical properties as for acoustic activated drug delivery. Methods Paclitaxel-loaded lipid microbubbles were prepared with two methods: one was mixed with phospholipids directly (Ⅰ); the other was added in triacetin, then mixed with phospholipids (Ⅱ). Concent ration, size, pH, drug entrapment efficiency, drug-loading amounts of these two kinds of paclitaxel-loaded lipid microbubbles were studied, while drug release with ultrasound and tumor imaging enhanced on rabbit breast tumor were observed. Results There was no significant difference in tumor imaging between two kinds of microbubbles which could be ruptured by low energy ultrasound. Compared with Ⅰ, the mean diameter of Ⅱ decreased significantly ([ 1.07±0.38] μm vs [2.79± 0.41] μm, P<0.01), the surface potencial was higher ([19.10±0.32] mV vs [-5.90±0.21] mV, P<0.01), whereas entrapment efficiency and drug-loading amounts increased markedly ([ 95.00±1.22]% vs [36.10±4.74]%, P<0.01; [5.60±0.11]% vs [0.50±0.04]%, P<0.01). Conclusion The Ⅱ paclitaxel-loaded lipid microbubbles added triacetin have an important clinical value.

Objective To assess the value of whole cerebral perfusion weighted map (PWM) and whole cerebral perfusion blood volume (PBV) integrating in scan protocol about CT perfusion (CTP) combined with CT angiography (CTA) in acute cerebral infarction. Methods Twenty-three patients with acute cerebral infarction proved clinically underwent CTP examination combined with CTA. The color-coded images of PWM and PBV were attained using workstation, and the raw data of contract CTA images and subtractive images between contract CTA and non-contract CTA were processed. The diagnostic sensitivity and the value of CTP and PWM, PBV integrating CTP in acute cerebral infraction were evaluated. Results Seven of 9 patients with negative results on CTP images had positive expressions on PWM and PBV images. The sensitivity of CTP was 60.87% and the sensitivity of PWM and PBV integrating CTP was 91.30%. Conclusion The scan protocol of PWM, PBV integrating CTP not only increases detection rate of acute cerebral infraction, but also has ability to predict the clinical prognosis of patients with cerebral infraction.

Objective To observe the value of dual source CT (DSCT) dual energy subtract method in diagnosis of lower extremity arterial occlusion. Methods Thirty-two patients with lower extremity arterial occlusive diseases underwent DSCT direct bone removal CT angiography (DE-BR-CTA) and digital subtraction angiography (DSA) within 2 weeks. Raw data were reconstructed with techniques including MIP and VR. Arterial visibility of DE-BR-CTA was analyzed by two experienced radiologists taking DSA as the standard. Results A total of 328 arterial segments were selected in 32 patients with lower extremity arterial occlusive diseases. The correlation between DSA and DE-BR-CTA was good. There was no significant difference in arterial visibility between DE-BR-CTA and DSA (P＞0.05). Compared with DSA, 12 of the segmental stenosis were overestimated and 6 were underestimated with DE-BR-CTA. When stenosis was over 10%, the accuracy, sensitivity, specificity, positive predictive value and negative predictive value of DE-BR-CTA was 94.51%, 96.15%, 93.02%, 92.59% and 96.39%, respectively. Conclusion DSCT energy subtraction angiography is an accurate diagnostic method and non-invasive imaging technology in the assessment of lower extremity arterial occlusive diseases. It may provide precious information for pre-surgery evaluation and screening the arterial diseases of the lower extremities.

Objective To detect different activated patterns of heavy smokers in different states as well as between smokers and non-smokers. Methods Seventeen subjects including 12 heavy smokers and 5 non-smokers (controls) were examined with functional magnetic resonance imaging (fMRI) performing smoking-related olfactory cue tasks. The data were processed with SPM2. These different patterns were compared between the two groups. Results When smokers were exposed to the smoking olfactory cue in the abstinent state, activation was found on the left superior frontal gyrus (BA8, 9, 10, 11), left middle frontal gyrus (BA8, 10, 11, 46), left inferior frontal gyrus (BA9), left medial frontal gyrus (BA6, 8, 10,11), right superior frontal gyrus (BA10), right middle frontal gyrus (BA8, 9), right inferior frontal gyrus (BA45, 47), right medial frontal gyrus (BA9, 11), left callosal gyrus (BA24, 31), right callosal gyrus (BA24, 37), right middle temporal gyrus (BA21) and both sides of the thalamus and cerebellum. When smokers were exposed to the smoking olfactory cue in the satiated state, activation could be found on both sides of the prefrontal lobe and cerebellar hemisphere, while there was no activation on the other brain regions. No activation was found on the whole brain of the nonsmokers,except for a little small volume active points appeared in individual subjects, possibly caused by the picture noise. Conclusion The Limbic system (cingulate cortex, thalamus) and the prefrontal lobe play an important role in the cue-induced smoking craving approved from the new perspective of the olfactory. It is feasible to research smoking addicts' brain activation and the role of neural mechanisms using olfactory stimulation with clinical 1.5T MRI equipment.

Objective To compare radiation dose and image quality between prospective and retrospective ECG gating CT coronary angiography (CTCA) with 64-slice CT scanner. Methods Sixty patients with suspected coronary artery disease were selected, and randomly devided into two groups. Thirty patients in research group (average body-mass index [BMI]:[25.30±3.15] kg/m~2, heart rate ≤65 beats per minute [bpm]) underwent CTCA using prospective ECG-gating (120 kV, mA tailored to weight), while the rest 30 patients in control group (average BMI:[25.40±3.00] kg/m~2, heart rate ≤65 bpm) underwent CTCA using retrospective ECG-gating (120 kV, 650 mA). The average effective dose (ED) and standardizing radiation dose (ED_(Sd)) which was standardized by 12 cm length were respectively calculated, and statistical analysis was then conducted, meanwhile image quality was evaluated. Results The average ED of research group and control group was (5.97±1.04) mSv and (26.25±2.36) mSv, respectively (t_(A,B)=43.13, P<0.05). The ED_(Sd) of two groups was (5.49±0.45) mSv and (23.77±1.64) mSv (t_(Sd)=59.00, P<0.05). ED_(Sd) decreased by 76.62% in research group compared with that of control group. No significant difference of image quality was found between two groups (χ~2=4.26, P=0.235). Conclusion Prospective ECG-gating CTCA can effectively reduce radiation dose without compromising image quality.