Investigation on the influence of AC electric filed and KCl on the structure and gel properties of Konjac glucomannan.

The influence of alternating current (AC) electric field and KCl on the structure and gel properties of Konjac Glucomannan (KGM) were studied in this work by high-performance gel permeation chromatography (HPGPC), acid-base titration, solid-state nuclear magnetic resonance (NMR), X-ray diffraction (XRD), simultaneous differential scanning calorimetry/thermo gravimetric analyzer (DSC/TGA) and a rheometer. HPGPC showed KGM was degraded by AC electric field and Acid-base titration showed that under the action of AC electric field and KCl KGM removed part of acetyl groups, which were consistent with the analysis of NMR. XRD and temperature sweep measurements respectively showed that the electrotreatment time and KCl concentration had important effects on the gel formation and its three-dimensional network. Simultaneous DSC/TGA and temperature sweep measurements both demonstrated the gel had good thermal stability.

Quantitative assessment of hepatic fibrosis in chronic hepatitis B and C: T1 mapping on Gd-EOB-DTPA-enhanced liver magnetic resonance imaging.

AIM: To assess the accuracy of Look-Locker on gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) for staging liver fibrosis in chronic hepatitis B/C (CHB/C). METHODS: We prospectively included 109 patients with CHB or CHC who underwent a 3.0-Tesla MRI examination, including T1-weighted and Look-Locker sequences for T1 mapping. Hepatocyte fractions (HeF) and relaxation time reduction rate (RE) were measured for staging liver fibrosis. A receiver operating characteristic analysis using the area under the receiver operating characteristic curve (AUC) was used to compare the diagnostic performance in predicting liver fibrosis between HeF and RE. RESULTS: A total of 73 patients had both pathological results and MRI information. The number of patients in each fibrosis stage was evaluated semiquantitatively according to the METAVIR scoring system: F0, n = 23 (31.5%); F1, n = 19 (26.0%); F2, n = 13 (17.8%); F3, n = 6 (8.2%), and F4, n = 12 (16.4%). HeF by EOB enhancement imaging was significantly correlated with fibrosis stage (r = -0.808, P < 0.05). AUC values for diagnosis of any (≥ F1), significant (≥ F2) or advanced (≥ F3) fibrosis, and cirrhosis (F4) using HeF were 0.837 (0.733-0.913), 0.890 (0.795-0.951), 0.957 (0.881-0.990), and 0.957 (0.882-0.991), respectively. HeF measurement was more accurate than use of RE in establishing liver fibrosis staging, suggesting that calculation of HeF is a superior noninvasive liver fibrosis staging method. CONCLUSION: A T1 mapping-based HeF method is an efficient diagnostic tool for the staging of liver fibrosis.

Bare-metal stents across the Vater's ampulla is a safe method for patients with lower bile duct obstruction.

This study explored the effect of the implant position of stents across the Vater's ampulla on treatment outcomes in patients with lower bile duct obstruction.In the retrospective study, 41 patients with malignant obstruction of the lower bile duct and obstructive jaundice received percutaneous transhepatic biliary placement of bare-metal stents. Basic demographic data on patients, such as sex, age, and primary diseases, and follow-up data, including postoperative complications and jaundice-free survival, were recorded. The follow-up data on patients with an involved ampulla, patients with an uninvolved ampulla, patients with a stent across the ampulla, and patients with a stent at a site other than the ampulla were compared. Furthermore, prognostic factors for jaundice- free survival were investigated using Cox proportional hazards regression analysis.Among the 41 patients, 38 patients experienced subsiding of jaundice, whereas 3 cases had unsuccessful stent patency. Whether or not the ampulla was involved did not influence the incidence rates of postoperative complications and the jaundice-free survival time. Notably, when stents were placed across the ampulla, the jaundice-free survival time was significantly longer than when stents were placed at sites other than across the ampulla (P < .05). Furthermore, placement of the stent across the ampulla or at other sites was an independent prognostic factor (hazard ratio = 0.154, 95% confidence interval 0.042-0.560, P = .005) for jaundice-free survival of patients.The current study revealed that the implant position of a stent across the ampulla resulted in maintenance of stent patency and prolongation of the jaundice-free survival time.

CT and MRI features in adult patients with orbital subperiosteal abscess secondary to paranasal sinus mucocele.

Orbital subperiosteal abscess (OSPA) secondary to paranasal sinus mucocele (PSM) is rare, and it may be misdiagnosed as PSM with orbital invasion or even as a malignant neoplasm. The present study explored the computed tomography (CT) and magnetic resonance imaging (MRI) features of OSPA. The cases of 13 patients with OSPA secondary to PSM were retrospectively reviewed. CT had been performed in 12, MRI in 7, and postcontrast MRI in 4. OSPA was revealed as a well-demarcated, spindle-shaped mass that was broad-based and located beneath the superior orbital wall (orbital roof) in 11 and at the medial wall in 2. PSM appeared as an expansile cystic lesion in the ethmofrontal sinus in 7, frontal sinus in 5, and ethmoidal sinus in 1. Because the OSPA was connected to the PSM, it looked like a single lesion involving both the orbit and the sinus. All 12 OSPAs examined on CT were low-density; 9 of the 12 PSMs were low-density and 3 were iso-density. Densities of the OSPAs and PSMs were equal in 4 and slightly different in 8. Five of the 10 OSPAs occurring beneath the orbital roof had unclear boundaries with the PSMs on CT. On MRI, although both OSPAs and PSMs mainly demonstrated hypointensity on T1-weighted images and hyperintensity on T2-weighted images, the signal intensities were slightly different, and linear-shaped hypointensity could be found between them. Postcontrast MRI revealed arch- and ring-shaped enhancement, respectively, at the edge of the OSPA and the PSM. Septal enhancement separated them more clearly. PSM is an important cause of OSPA in adults. CT and MRI can accurately display these entities' characteristic findings and their anatomic relationship, as well as playing an important role in the differential diagnosis.

Hybrid PET/MRI-based delineation of gross tumor volume in head and neck cancer and tumor parameter analysis.

OBJECTIVES: Accurate target delineation allows an increase in radiation dose to the target tumor while reducing damage to the surrounding normal tissue. However, there is currently no standard for evaluating volumes measured by different imaging modalities. The aim of this study is to evaluate the feasibility of contouring gross tumor volume (GTV) by PET/MRI in head and neck cancer, and to define an adaptive threshold level (aTL) for delineating the biological target volume (BTV). PATIENTS AND METHODS: Eighteen head and neck cancer patients underwent time of flight PET/MRI before chemoradiotherapy. Different GTVs of primary tumors and metastatic lymph nodes were manually contoured on MRI (GTVMRI), PET (GTVVIS), and fused PET/MRI (GTVFUS). An MRI-based GTV contour was substituted for the pathologic GTV. The percentile threshold boundary of the maximum standardized uptake value (SUVmax) for the BTV was determined when the volume of BTV approached that of GTVMRI. RESULTS: All GTVs were highly correlated (all Pearson's r>0.85, all P<0.001). Tumor diameter strongly correlated with GTVs (r=0.7-0.8 for all lesions and primary tumor; r=0.8-0.9 for lymph node metastases). aTL and SUVmax were moderately correlated for all lesions (r=-0.692, P<0.001) and were strongly correlated for primary tumors (r=-0.866, P<0.001). CONCLUSION: Delineating GTV on hybrid PET/MRIs is feasible, and aTL, the threshold boundary of BTV, was correlated inversely with the SUVmax.

Early diagnosis and severity assessment of acute pancreatitis (AP) using MR elastography (MRE) with spin-echo echo-planar imaging.

PURPOSE: To evaluate the accuracy of magnetic resonance elastography (MRE) in comparison to contrast-enhanced computed tomography (CE-CT) for early diagnosis and prediction of severity in acute pancreatitis (AP). MATERIALS AND METHODS: This cross-sectional prospective study included 76 patients with suspected AP who underwent both CE-CT and 3.0T MRE within 24 hours of hospital admission. Pancreatic stiffness, CT severity index (CTSI), Acute Physiology and Chronic Health Evaluation (APACHE)-II, and Bedside Index for Severity in AP (BISAP) scores were comparatively evaluated using data from the first 24 hours of admission, and diagnosis and severity of AP were confirmed according to the revised Atlanta Classification (2012). The accuracy of MRE for predicting disease severity was compared with that of CE-CT and the clinical scoring systems using area under the receiver-operating curve (AUC) analysis. RESULTS: AP was confirmed in 56/76 patients (73.7%). Pancreatic stiffness values of >1.47 kPa showed significantly better diagnostic performance than CE-CT (AUC: 0.993 vs. 0.818, P < 0.001) along with greater sensitivity (96.4% vs. 78.6%, P = 0.006) and accuracy (96.1% vs. 81.6%, P = 0.007). Ten patients (10/76; 13.2%) had clinically severe AP. The accuracy of pancreatic stiffness >2.47 kPa was comparable to that of the CTSI, APACHE-II and BISAP scores for predicting severe AP (accuracy = 85.5%, 75.0%, 88.2%, and 78.9%, respectively). The pairwise comparisons were not significant after Bonferroni correction (P < 0.008 [0.05/6]), with P values of 0.008 (MRE vs. CTSI), 0.823 (MRE vs. APACHE-II) and 0.414 (MRE vs. BISAP). CONCLUSION: Early MRE is a useful, noninvasive method for both diagnosis and early severity assessment of AP. We recommend MRE at hospital admission for initial evaluation of AP. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017;46:1311-1319.

Magnetic Resonance Elastography for the Evaluation of Liver Fibrosis in Chronic Hepatitis B and C by Using Both Gradient-Recalled Echo and Spin-Echo Echo Planar Imaging: A Prospective Study.

OBJECTIVES: Magnetic resonance elastography (MRE) with three-dimensional spin-echo echo planar imaging (3D-SE-EPI) is a newly emerging noninvasive method for assessing liver fibrosis. We hypothesized that 3D-SE-EPI might have better diagnostic accuracy than conventional two-dimensional gradient-recalled echo (2D-GRE). METHODS: We prospectively included 179 consecutive patients with chronic hepatitis B (CHB) or C (CHC) who underwent both MRE and liver biopsy. Liver stiffness was measured by both 3D-SE-EPI and 2D-GRE for staging biopsy-proven liver fibrosis (using METAVIR scores). A receiver-operating characteristic analysis using the area under the receiver-operating characteristic curve (AUC) was used to compare the diagnostic performance in predicting liver fibrosis between these two techniques, and compared them to serum markers of fibrosis. RESULTS: The technical failure rate of 3D-SE-EPI (2.2%, n=4/179) was lower compared with 2D-GRE (8.3%, n=15/179). The stiffness measured by 3D-SE-EPI was slightly lower compared with 2D-GRE, with the mean difference of 0.57 kPa (Bland and Altman plot, 95% limits of agreement: -0.32 and 1.45 kPa). AUCs for the characterization of ≥F1, ≥F2, ≥F3, and F4 were 0.957 (95% confidence interval (CI): 0.913-0.983), 0.971 (0.932-0.991), 0.991 (0.961-0.999), and 0.979 (0.942-0.995) for 3D-SE-EPI, which was slightly higher compared with the AUCs for 2D-GRE at each fibrosis stage (0.948 (0.901-0.977), 0.959 (0.915-0.981), 0.979 (0.943-0.995), and 0.976 (0.938-0.994), respectively), although none reached statistical significance (P=0.160-0.585). In an "intention-to-diagnose" analysis, the diagnostic accuracy (the proportion of well-classified patients) by EPI (86.7-91.3%, n=169) was higher compared with GRE (80.9-82.1%, n=158) after applying optimal cutoffs. Both 3D-SE-EPI and 2D-GRE performed better than serum fibrosis markers. CONCLUSIONS: With respect to 2D-GRE, 3D-SE-EPI has the advantage of lower failure rate with equivalent high diagnostic performance for staging liver fibrosis in CHB/CHC patients, and thus more helpful for those challenging cases in 2D-GRE.

Hemobilia After Laparoscopic Cholecystectomy: Imaging Features and Management of an Unusual Complication.

PURPOSE: To assess the imaging features and the management of hemobilia after laparoscopic cholecystectomy (LC). MATERIALS AND METHODS: A total of 12 patients who were treated for hemobilia after LC were included in the study. Selective arteriography was performed to find the bleeding artery. Coils or microcoils were deployed superselectively to occlude the bleeding branch. The clinical course, imaging findings, the embolic effect, complications, and follow-up were evaluated. RESULTS: Risk factors for hemobilia included a variant ductal anatomy, a variant cystic artery, and intraoperative adhesion. Abdominal computed tomography (CT) could provide the diagnostic signs as follows: a hematocele in the abdominal cavity, the gallbladder fossa, and the bile duct, biliary dilation, pseudoaneurysm of the right hepatic artery, and contrast extravasations on contrast-enhanced CT. No rebleeding occurred after the transcatheter arterial embolization in all patients without immediate procedural complications. CONCLUSIONS: Gallbladder triangle anatomic variation and intraoperative adhesion were the risk factors for hemobilia after LC. Abdominal CT is a useful examination for the diagnosis. Transcatheter arterial embolization is the therapeutic option of choice.

Quantitative assessment of early liver fibrosis in rats using 13N-NH3·H2O PET/CT.

OBJECTIVE: To investigate the value of N-NH3·H2O PET/computed tomography (CT) and the inhibitor, acetazolamide (ACZ), in the quantitative diagnosis of early liver fibrosis and the assessment of liver fibrosis stage. MATERIALS AND METHODS: Twenty-four male Wistar rats (293.54±37.99 g) were used in this study and grouped by pathology after biopsy. Using N-NH3·H2O as an imaging agent and ACZ as an aquaporin 1 inhibitor, the rats were subjected to a dynamic PET/CT scan for 45 min. According to data reconstruction and imaging analysis, we calculated the mean standard uptake value (SUVmean) of the liver at the time points of 20, 90 s, 5, 10, 15, 20, and 25 min. From the results of N-NH3·H2O, the liver SUVmean in the control group and the liver fibrosis model group at different time points were compared. In addition, blood perfusion, interstitial diffusion, and N-NH3·H2O metabolism of the two groups were compared. Single-factor analysis of variance was used to analyze the differences between the SUVs in the groups at any time point and the paired-sample t-test was used to compare the SUVs before and after addition of the inhibitor. RESULTS: We included four rats in the control group (S0) and 20 rats in the liver fibrosis group (which included early-stage S1: 11 rats, progressive-stage S2+S3+S4: nine rats). Three rats in S0, seven rats in S1, and six rats in S2+S3+S4 were paired. The SUVmean at 90 s was statistically different (P<0.05); however, the other groups showed statistical difference at all time points (P>0.05). After the addition of the inhibitor, ACZ, the SUVmean of S0 and S2+S3+S4 at 10, 15, 20, and 25 min was statistically different (P<0.05). CONCLUSION: N-NH3·H2O PET/CT may aid the diagnosis of liver fibrosis. N-NH3·H2O PET/CT combined with ACZ may help distinguish between the early stage and the progressive stage of liver fibrosis.

Sequential Use of Transhepatic Arterial Chemoembolization and Bipolar Radiofrequency Ablation in the Clinical Therapy of Hepatocellular Carcinoma.

This retrospective study investigated the clinical application of sequential therapy with transarterial chemoembolization (TACE) and CT-guided radiofrequency ablation (RFA) using a bipolar needle in treating hepatocellular carcinoma (HCC) tumors of different sizes. The study included patients (N = 46) with HCC from Shengjing Hospital of China Medical University who had received TACE and RFA from November 2012 to November 2013. Eligible patients had an Eastern Cooperative Oncology Group (ECOG) score of 0-1, a Child-Pugh grade of A-B, and no contradictions for TACE and/or RFA. Fifty one hepatic lesions of varying sizes were treated with TACE followed by RFA. Clinical response and 1- and 2-year survival rates were assessed. The frequency of complete and incomplete ablation following therapy was significantly different across the varying RFA pin numbers and the maximum diameter of the lesion (p ≤ 0.001). A greater percentage (97.3%) of lesions that were ≤3 cm in diameter were completely ablated compared with lesions that were 3-5 cm (88.9%) and >5 cm in diameter (20%). The median survival time of patients was 16.5 months, and the 1- and 2-year survival rates were 95.7% and 69.3%, respectively. There were only a limited number of complications, all of which were minor. These included hemothorax (4.3%), abdominal hemorrhage (10.9%), and abdominal hemorrhage with minor pneumothorax (2.2%). This study found that the sequential treatment with TACE and CT-guided RFA using a bipolar needle is effective and well tolerated in patients with HCC and that the effectiveness of treatment is dependent on tumor size.

Meta-analysis comparing higher and lower dose radiotherapy for palliation in locally advanced lung cancer.

The purpose of this meta-analysis was to compare higher dose (≥30 Gy) and lower dose (<30 Gy) radiotherapy (RT) on palliation of symptoms and survival in patients with locally advanced lung cancer. A search of PubMed and Google Scholar was conducted on 10 June 2013 using combinations of the search terms: radiotherapy, non-small-cell lung carcinoma, palliative, supportive, symptom relief. Inclusion criteria were: (i) palliative thoracic RT; (ii) randomized controlled trial; (iii) English language; and (iv) compared outcomes between higher dose (≥30 Gy) and lower dose (<30 Gy) RT. The primary outcome was palliation of symptoms (cough, chest pain, hemoptysis), and 1- and 2-year overall survival. Tests of heterogeneity, sensitivity, and publication bias were performed. Five randomized controlled trials with a total of 1730 patients with lung cancer were included in the meta-analysis. There were 925 patients treated with a higher RT dose (≥30 Gy) and 805 treated with a lower RT dose (<30 Gy). The combined odds ratios (ORs) indicated no significant difference in palliation of cough, chest pain, and hemoptysis between the higher dose and lower dose RT groups (combined ORs = 0.88, 1.83, 1.39, respectively). The 1- and 2-year OS rates were similar between the high and low dose RT groups (combined ORs = 1.09 and 1.38, respectively). This meta-analysis indicates that high dose (≥30 Gy) and lower dose (<30 Gy) RT provide similar symptom palliation and 1- and 2-year OS in patients with locally advanced lung cancer.

Detection of residual tumor following radiofrequency ablation of liver metastases using 18F-FDG PET/PET-CT: a systematic review and meta-analysis.

Radiofrequency ablation (RFA), an effective, locally directed therapy for unresectable liver metastases, can improve the survival of patients. As a functional imaging approach, (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) or PET-computed tomography (PET-CT) may play a crucial role in the follow-up after RFA. Our objective was to evaluate the diagnostic accuracy of (18)F-FDG PET or PET-CT for the detection of residual tumor following RFA of liver metastases. Studies reporting the diagnostic value of (18)F-FDG PET or PET-CT for patients with residual tumor after RFA of liver metastases were identified. The methodological quality of these studies was systematically evaluated, and the overall sensitivity and specificity of these data sets are reported. Seven studies involving 155 patients were examined. When (18)F-FDG PET or PET-CT was performed within 2 days of RFA, the overall sensitivity and specificity were 79% [95% confidence interval (CI): 70-87%] and 84% (95% CI: 75-91%), respectively. When (18)F-FDG PET or PET-CT was performed 1 week after treatment, the pooled sensitivity and specificity were 48% (95% CI: 18-79%) and 94% (95% CI: 70-100%), respectively. Finally, when (18)F-FDG PET or PET-CT was performed 3 months after treatment, the pooled sensitivity and specificity were 52% (95% CI: 22-81%) and 94% (95% CI: 70-100%), respectively. Both (18)F-FDG PET and PET-CT are effective in detecting residual tumor following RFA of liver metastases. The ideal time to perform these imaging studies is within 2 days of RFA treatment.

Expression of N-methyl-d-aspartate receptor 1 and its phosphorylated state in basal ganglia of a neonatal piglet hypoxic-ischemic brain injury model: a controlled study of (1)H MRS.

Excitatory amino acids (EAAs) and excitotoxicity medicated by receptors of these amino acids play an important role in hypoxic-ischemic brain injury (HIBI), but most studies were ex vivo experiments, the mechanism in vivo is not well understood. We sought to study the expression of N-methyl-d-aspartate receptor 1 (NR1) and phosphorylated N-methyl-d-aspartate receptor 1 (P-NR1) in basal ganglia in a piglet model of HIBI and to investigate the correlation between Glx(Glu/Gln) value measured by magnetic resonance spectroscopy (MRS) and NR1/P-NR1 expression. Multi-voxel (1)H MRS was applied to detect change in Glx in basal ganglia of the newborn piglets in vivo. Automatic amino acid analyzer was applied to accurately quantify the Glu concentration. Immunohistochemical method was used to examine the expression of NR1 and P-NR1. The NR1 receptors in basal ganglia of the newborn piglets were significantly activated after HIBI. P-NR1 expression in the basal ganglia was consistent with the change in brain Glu content, so the activation status of NMDA receptor in the brain could be indirectly reflected by ß-, γ-Glx/NAA measured by (1)H MRS.

Comparison between acetazolamide challenge and 10% carbon dioxide challenge perfusion CT in rat C6 glioma.

RATIONALE AND OBJECTIVES: The aim of this study was to investigate the effect of perfusion computed tomography (PCT) with acetazolamide (ACZ) challenge and compare it to 10% carbon dioxide (CO(2)) challenge in rat C6 glioma. MATERIALS AND METHODS: PCT was performed on 32 rats, including 20 with orthotopically implanted C6 gliomas and 12 serving as controls. Ten rats with gliomas and six normal rats underwent PCT with ACZ challenge. The other 10 rats with gliomas and six normal rats underwent PCT with 10% CO(2) challenge. The raw data were processed using Philips computed tomographic brain perfusion software. Perfusion parameters before and after the challenge were recorded. Percentage changes due to ACZ administration and 10% CO(2) challenge were calculated. Pearson's correlation coefficients were used to investigate relationships between percentage changes in perfusion parameters and vascular endothelial growth factor and microvessel density. RESULTS: In C6 gliomas, percentage change in cerebral blood flow was significantly different between ACZ (72.73%) and 10% CO(2) (28.47%) challenge (P < .01). Percentage change in cerebral blood volume was 37.85% with ACZ and 24.69% with 10% CO(2) challenge (P = .02). In controls, percentage change in cerebral blood flow was significantly different between ACZ (117.42%) and 10% CO(2) (65.86%) challenge (P < .01). For percentage change in cerebral blood volume, there was no significant difference between ACZ (107.51%) and 10% CO(2) (92.95%) challenge. Significant correlations were observed among percentage changes in vascular endothelial growth factor, microvessel density, and cerebral blood volume (P < .01). Percentage change in cerebral blood flow correlated well with vascular endothelial growth factor. CONCLUSIONS: The results of this study indicate that PCT with ACZ challenge is a more reliable technique compared to 10% CO(2) challenge for the quantitative evaluation of microcirculation in gliomas.

Simultaneously changes in striatum dopaminergic and glutamatergic parameters following hypoxic-ischemic neuronal injury in newborn piglets.

Basal ganglia injury (BGI) is a type of perinatal hypoxic-ischemic (H-I) brain injury. Both malfunctions of glutamatergic and dopaminergic pathways in striatum were suggested to contribute to BGI. In current study, we investigated the imaging profile of glutamate (Glx) levels by proton magnetic resonance spectroscopy ((1)H-MRS), and the expression of dopamine D2 receptors (D2R) and dopamine transporter (DAT) by immunohistochemical staining in a newborn piglet model of H-I brain injury. We found that the number of striatal D2R positive neurons decreased following H-I brain injury, and the decrease in positive neuron number was consistent with the degree of striatum. Following H-I brain insult, the number of striatal DAT positive neurons and glutamate level were simultaneously increased initially, followed by a gradual decline toward control level. There was a positive correlation between the changes in striatal DAT positive neurons and glutamate level following H-I brain insults in newborn piglets. Our findings suggest that following H-I brain insult, striatal D2R positive neurons decreased due to neuron death; straital DAT initially increased to compensate for dopamine uptake; and glutamatergic and dopaminergic systems in striatum may act in an interdependent way in the striatum of newborn piglets.

Effects of hypoxic-ischemic brain injury on striatal dopamine transporter in newborn piglets: evaluation of 11C-CFT PET/CT for DAT quantification.

INTRODUCTION: Alterations of dopamine in striatal presynaptic terminals play an important role in the hypoxic-ischemic (HI) brain injury. Quantification of DAT levels in the presynaptic site using (11)C-N-2-carbomethoxy-3-(4-fluorophenyl)-tropane ((11)C-CFT) with positron emission tomography (PET) was applied in studies for Parkinson's disease. The current study investigated the changes in striatal DAT following HI brain injury in newborn piglets using (11)C-CFT PET. METHODS: Newborn piglets were subjected to occlusion of bilateral common carotid arteries for 30 min and simultaneous peripheral hypoxia. Brain DAT imaging was performed using PET/CT with (11)C-CFT as the probe in each group (including the control group and HI insult groups). Brain tissues were collected for DAT immunohistochemical (IHC) analysis at each time point post the PET/CT procedure. Sham controls had some operation without HI procedure. RESULTS: A few minutes after intravenous injection of (11)C-CFT, radioactive signals for DAT clearly appeared in the cortical area, striatum and cerebellum of newborn piglets of sham control group and HI insult groups. HI brain insult markedly increased striatal DAT at an early period (P<.05 vs. sham controls) when neuronal pathological changes were mild. Changes in striatal DAT were absent at later period post-HI insult when neuronal injury became more severe. (11)C-CFT PET imaging data and IHC DAT staining data were highly correlated (r=0.844, P<.05). CONCLUSIONS: HI brain injury resulted in a transient increase in striatal DAT. (11)C-CFT PET/CT imaging data reflected the dynamic changes of DAT in the striatum in vivo.

64-slice CT perfusion imaging of pancreatic adenocarcinoma and mass-forming chronic pancreatitis.

RATIONALE AND OBJECTIVES: To investigate 64 computed tomography (CT) perfusion imaging features of patients with pancreatic cancer and mass-forming chronic pancreatitis. MATERIALS AND METHODS: Between January 2003 and April 2010, 234 patients with pancreatic mass underwent 64-CT perfusion imaging. Among them, the histopathological results of 64 patients were proven to be pancreatic adenocarcinoma and 15 patients were proven to be mass-forming chronic pancreatitis. Additionally, CT perfusion imaging was performed in 33 healthy volunteers served as controls. The slice data were processed using CT perfusion software. Perfusion parameters including time density curve, blood flow, blood volume, permeability, peak enhancement, and time to peak were recorded. RESULTS: Blood flow was 77% lower in patients with pancreatic adenocarcinoma than in controls, 48% lower in patients with mass-forming chronic pancreatitis than in controls, and 56% lower in patients with pancreatic adenocarcinoma than with mass-forming chronic pancreatitis (P < .016). Blood volume was 65% lower in pancreatic adenocarcinoma than in controls, 27% lower in mass-forming chronic pancreatitis than in controls, and 53% lower in cancer than mass-forming chronic pancreatitis (P < .016). Permeability was 559% higher in pancreatic adenocarcinoma than in controls, 821% higher in mass-forming chronic pancreatitis than in controls, and 28% lower in cancer than mass-forming chronic pancreatitis (P < .016). Peak enhancement was 27% lower and time to peak 23% longer in pancreatic adenocarcinoma than mass-forming chronic pancreatitis (P < .016). Time-density curve showed the peak of mass-forming chronic pancreatitis is earlier and higher than that of pancreatic adenocarcinoma, and the peak of mass-forming chronic pancreatitis is later and lower than that of controls. CONCLUSION: CT perfusion imaging can provide additional quantitative hemodynamic information of pancreatic adenocarcinoma and mass-forming chronic pancreatitis.

Normal cranial bone marrow MR imaging pattern with age-related ADC value distribution.

OBJECTIVE: To determine MRI appearances of normal age-related cranial bone marrow and the relationship between MRI patterns and apparent diffusion coefficient (ADC) values. METHODS: Five hundred subjects were divided into seven groups based on ages. Cranial bone marrow MRI patterns were performed based on different thickness of the diploe and signal intensity distribution characteristics. ADC values of the frontal, parietal, occipital and temporal bones on DWI were measured and calculated. Correlations between ages and ADC values, between patterns and ADC values, as well as the distribution of ADC values were analyzed. RESULTS: Normal cranial bone marrow was divided into four types and six subtypes, Type I, II, III and IV, which had positive correlation with age increasing (χ2=266.36, P<0.01). The ADC values of normal parietal and occipital bone marrow showed significant negative correlation with age growing (r=-0.561 and -0.622, P<0.01), while there were no significant differences of that with age increasing in frontal and temporal bone marrow (P>0.05). In addition, there was significant negative correlation between the ADC values and MRI patterns in the normal parietal and occipital bones (r=-0.691 and -0.750, P<0.01). CONCLUSION: The combination of MRI features and ADC values changes in different cranial bones showed significant correlation with age increasing. Familiar with the MRI appearance of the normal bone marrow conversion pattern in different age group and their ADC value will aid the diagnosis and differential of the cranial bone pathology.