The Application Of320-slice CT Perfusion Imaging And Adaptive Iterative Dose Reduction In Rectal Cancer

Part1PurposeMy Research is to study the rectal cancer (rectal cancer, RC)by Toshiba320-slice spiral CT perfusion imaging techniques, the resulting time-density curve(time-density curve, TDC), the value of CT perfusion parameters and tumor staging,CEA value of the size, there is or no depth of invasion, there is or no lymph node anddistant metastasis.MethodThe39cases of colorectal cancer patients (including20males and19females,mean age63.2years) were Bowel preparation before the tests were carried out toclean bowel preparation: Check before3d ring fiber diet. After the previous day early,eat a light lunch, low fat low residue diet, liquid diet the night before, the day offasting morning contrast,2h after breakfast the day before Senna10g+500ml waterimmersion30m in drink, lunch2h500ml drinking water soak again, after dinner,2h10%mannitol solution1000m l drinking.10min before the scan to be654.2intramuscular injection10mg. Injection of1000~1500ml of warm saline enema, sobowel full expansion. All patients were320multi-slice perfusion imaging by Toshibabody perfusion software applications to analyze blood perfusion and, to analysisusing a single algorithm for maximum slope and Patlak plotting tools (cartography).Delineate the target artery and soft tissue time density curve. Independently by thetwo skilled physicians, three times, it is measurements were repeated each parametervalue and record the size of the measured the region of interest (ROI.) After onemonth, where in the measurement is repeated once a physician to calculate theaverage value. To give the blood volume (blood volume BV), blood flow (blood flowBF), surface permeability (permeability surface PS). According to TNM staging lesions, TDC curves were classified according to the form. The CT perfusionparameters and TNM staging, and CEA, there is or no lymph node and distantmetastasis, there is or no depth of invasion, and other factors of relevance forstatistical analysis.ResultThe TDC curve shape can be classified according to five types of tumors ofdifferent stages TDC curve can be expressed as the five type one or several, MTT, BVand serous infiltration are correlated (t=-3.03and.-3.14, P=0.0107and0.0321),BV was positively correlated with tumor size (r=0.31, P=0.01), BF, MTT andtumor stage, distant metastasis and CEA, depth of invasion, lymph node metastasis,etc. are unrelated (P>0.05).ConclusionToshiba320-slice low-dose CT perfusion imaging can reflect RC perfusion,clinical treatment programs may provide some objective basis, and Due to the lowradiation dose, and can be spread. Part2The Application value of low kilovoltage and adaptiveiterative dose reduction for the rectal cancer (RC) scanningObjectiveTo explore the application value of low kilovoltage and adaptive iterative dosereduction (AIDR) for optimizing infant the rectal cancer (RC) CT scanning.Methods:CT examination of the collection ready rectal tumors were randomly selected40patients were divided into two groups A and B, A group (low-dose group)20cases,11males and9females, aged44-69years old, with a median age of51years; another20 cases of group B (control group),10males and10females, aged39-71years old,with a median age of61years. Bowel preparation before the tests were carried out toclean bowel preparation: Check before3d ring fiber diet. After the previous day early,eat a light lunch, low fat low residue diet, liquid diet the night before, the day offasting morning contrast,2h after breakfast the day before Senna10g+500ml waterimmersion30m in drink, lunch2h500ml drinking water soak again, after dinner,2h10%mannitol solution1000m l drinking.10min before the scan to be654.2intramuscular injection10mg. Injection of1000~1500ml of warm saline enema, sobowel full expansion. A set of scanning tube voltage of80kV, using volume scanningand (FBP) reconstruction techniques, group A patients scanned that using the iterativedose reduction algorithm to adapt reconstruction technique (AIDR) get A1group;group B100kV, using conventional filtered back projection (FBP) reconstructiontechniques. CT values were compared with the standard difference between the psoasmuscle (SD), signal to noise ratio (SNR), contrast to noise ratio (CNR), image qualityscore and effective dose (ED).ResultsThere was no significant difference in mean image quality scores between twogroups (4.56±0.48in group A, vs.4.61±0.45in group B. χ２=-2.58, p>0.05). Thevalues of CT and SD in group A were higher than those in group B(t=1.142,2.80,respectively, p>0.05). The values of SNR and CNR in group A were lower than thosein group B(t=1.03,0.59, respectively, p<0.05). The value of ED in group A wasdecreased by65％compared to group B (t=-14.30, P>0.05).ConclusionThe images of infant chest CT scanning with80kV tube voltage and ADIRreconstruction can obtain optimal images quality for diagnosis requirement, with thereduction of radiation dose by65%.