To explore diagnostic acuity of helical CT colonscopic examination, simulated polyps were reproduced in 10 pig colons and 6 human colons obtained from colon resection. Helical CT colonoscopic scanning with different parameters was performed. The images were evaluated with Nav, Axial+MPR, SSD+Raysum. The diagnostic sensitivity of each method for the detection of simulated colonic polyps were assessed. The results indicated that the image quality of CT colonoscopy was improved with the decrease in collimation and pitch. The optimal angle of the colon lumen to the gantry was 90?. CT colonoscopy was superior to other imaging methods. Therefore, the performance of CTVC has a close relationship with the scanning parameters. The optimal scanning parameters were 5mm collimation, 1 5 pitch, and filling the colon with air. The combination of CTVC with other imaging methods would contribute to improving the diagnostic accuracy for the detection of colonic polyps.

Objective To explore the effect of D-galactose(D-gal) on murine pancreatic injury and its pathogenesis.Methods C57BL/6J mice were randomly divided into control group and D-gal model group [D-gal 120 mg/(kg · d) for 42 days].On the 2nd day after drug injection completed,the peripheral blood was taken for measuring the level of fasting blood glucose(FBG) and fasting insulin(FINS);and then the organ index of pancreas was calculated by the ratio of pancreatic wet weight(mg) and mouse body weight(g);HE stain was routinely prepared to observe the histologic structure of pancreatic tissue;the TEM was used to analyze ultrastructural changes of pancreatic cells;the pancreatic frozen sections were prepared to test senescence-associated β-galactosidase (SA-β-gal) and its relative absorbance(RA) of positively stained cells in the pancreatic islets;immunohistochemistry assays to study advanced glycation end products (AGEs) and its RA;pancreas tissue homogenate was made to detect the content of superoxide dismutase(SOD),malonaldehyde(MDA) and total antioxidant capacity(T-AOC).Results In D-gal group mice,the FBG increased(P＜0.05) and FINS reduced;pancreas wet weight and organ increased obviously (P＜0.01);light microscopic structure of the pancreas presented without typical pathologic change,however the single nucleated cell's area within the islet was increased significantly(P＜0.05);the pancreas endocrine and exocrine cells were showed the ultrastructure damaged and lipofuscin formation increased;the RA of positive pancreas cells in SA-β-gal staining increased(P＜0.05);the RA of AGEs positive regional expression markedly increased (P＜0.01);the content of SOD and T-AOC decreased (P ＜ 0.05),the content of MDA increased (P ＜ 0.01).Conclusions Aging mice model replicated by D-gal can cause the pancreatic injury,its mechanisms may be closely related to oxidative injury of pancreatic cells caused by D-gal.

OBJECTIVETo develop a computed tomography myocardial perfusion (CT-MP) deconvolution algorithm by incorporating high-dimension total variation (HDTV) regularization.

METHODSA perfusion deconvolution model was formulated for the low-dose CT-MPI data, followed by HDTV regularization to regularize the consistency of the solution by fusing the spatial correlation of the vascular structure and the temporal continuation of the blood flow signal.

RESULTSBoth qualitative and quantitative studies were conducted using XCAT and pig myocardial perfusion data to evaluate the present algorithm. The experimental results showed that this algorithm achieved hemodynamic parameter maps with better performances than the existing methods in terms of streak-artifacts suppression, noise-resolution tradeoff, and diagnosis structure preservation.

CONCLUSIONThe proposed algorithm can achieve high-quality hemodynamic parameter maps in low-dose CT-MPI.

OBJECTIVETo compare two methods for threshold selection in Huber regularization for low-dose computed tomography imaging.

METHODSHuber regularization-based iterative reconstruction (IR) approach was adopted for low-dose CT image reconstruction and the threshold of Huber regularization was selected based on global versus local edge-detecting operators.

RESULTSThe experimental results on the simulation data demonstrated that both of the two threshold selection methods in Huber regularization could yield remarkable gains in terms of noise suppression and artifact removal.

CONCLUSIONBoth of the two methods for threshold selection in Huber regularization can yield high-quality images in low-dose CT image iterative reconstruction.

OBJECTIVETo minimize of the radiation dose of cardiovascular CT angiography (CTA) imaging while preserving the image quality.

METHODSTo reduce the radiation dose in CTA imaging, the normal-dose scan induced non-local means (ndiNLM) algorithm was adapted for low-mAs scanned CTA image restoration by using the previous scanned high-quality image.

RESULTSQualitative and quantitative evaluations were carried out on both simulated phantom and clinical CTA scans in terms of accuracy and resolution properties. Compared to the original NLM algorithm, the ndiNLM method could achieve noticeable gains in terms of noise-induced artifacts suppression and enhanced structure preservation.

CONCLUSIONThe ndiNLM algorithm is a potential useful technique to reduce the radiation dose in CTA imaging.

Lymphatic system is the transportation way of cerebrospinal fluid and brain interstitial fluid exchange. And this system is a central nervous drainage system which plays an important role in drainaging and discharging of metabolic waste in the brain. The function of this system can be evaluated indirectly by the perivascular space on magnetic resonance imaging. Parkinson′s disease is a common neurodegenerative disorder. It may be helpful to control the progression of the disease if the changes of perivascular space can be dynamically observed in the early or even prodromal stage of the disease. This article reviews the relationship between lymphatic system disfunction and early stage of Parkinson′s disease.

Objective To minimize of the radiation dose of cardiovascular CT angiography (CTA) imaging while preserving the image quality. Methods To reduce the radiation dose in CTA imaging, the normal-dose scan induced non-local means (ndiNLM) algorithm was adapted for low-mAs scanned CTA image restoration by using the previous scanned high-quality image. Results Qualitative and quantitative evaluations were carried out on both simulated phantom and clinical CTA scans in terms of accuracy and resolution properties. Compared to the original NLM algorithm, the ndiNLM method could achieve noticeable gains in terms of noise-induced artifacts suppression and enhanced structure preservation. Conclusion The ndiNLM algorithm is a potential useful technique to reduce the radiation dose in CTA imaging.

Objective To minimize of the radiation dose of cardiovascular CT angiography (CTA) imaging while preserving the image quality. Methods To reduce the radiation dose in CTA imaging, the normal-dose scan induced non-local means (ndiNLM) algorithm was adapted for low-mAs scanned CTA image restoration by using the previous scanned high-quality image. Results Qualitative and quantitative evaluations were carried out on both simulated phantom and clinical CTA scans in terms of accuracy and resolution properties. Compared to the original NLM algorithm, the ndiNLM method could achieve noticeable gains in terms of noise-induced artifacts suppression and enhanced structure preservation. Conclusion The ndiNLM algorithm is a potential useful technique to reduce the radiation dose in CTA imaging.

Objective To compare two methods for threshold selection in Huber regularization for low-dose computed tomography imaging. Methods Huber regularization-based iterative reconstruction (IR) approach was adopted for low-dose CT image reconstruction and the threshold of Huber regularization was selected based on global versus local edge-detecting operators. Results The experimental results on the simulation data demonstrated that both of the two threshold selection methods in Huber regularization could yield remarkable gains in terms of noise suppression and artifact removal. Conclusion Both of the two methods for threshold selection in Huber regularization can yield high-quality images in low-dose CT image iterative reconstruction.

Objective To compare two methods for threshold selection in Huber regularization for low-dose computed tomography imaging. Methods Huber regularization-based iterative reconstruction (IR) approach was adopted for low-dose CT image reconstruction and the threshold of Huber regularization was selected based on global versus local edge-detecting operators. Results The experimental results on the simulation data demonstrated that both of the two threshold selection methods in Huber regularization could yield remarkable gains in terms of noise suppression and artifact removal. Conclusion Both of the two methods for threshold selection in Huber regularization can yield high-quality images in low-dose CT image iterative reconstruction.