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Objective To study the feasibility of applying electronic cleaning to intestinal contents tagging by diatrizoate meglumine for single-source dual-energy CT colonography with sequential acquisitions and volume scanning.Methods Twenty-four volunteers had fine effect of intestinal contents tagging by diatrizoate meglumine,good colorectal distension effect,fine image quality of dual-energy fusion colorectal images,and with informed consents were enrolled in this study.The single-source dual-energy CT colonography with sequential acquisitions and volume scanning was performed with an Acquilion ONE 320 row CT scanner,tube voltage 135 kVp/80 kVp.The intestinal contents conducted the dual-energy electronic cleaned based on decomposition of intestinal contents tagging by diatrizoate meglumine,soft tissue and air.The intestinal contents in one segment of intestinal lumen being 100％ electronically cleaned served as the basic standard,the electronic cleaning effects were divided into the 5 grades:excellent,good,moderate,fair and poor;and grade 1-3 were effective fecal electronic cleaning.Results The grade 1,2,3,4,5 of electronic cleaning effect for solid as the main intestinal contents were 22.2％,53.3％,17.8％,6.7％ and 0％ respectively;and which of electronic cleaning effect for liquid as the main intestinal contents were 47.5％,47.5％,5.0％,0％ and 0％ respectively.The together total effective electronic cleaning of intestinal contents was 97.9％ and the electronic cleaning effect was good.Conclusion Electronic cleaning could be used in the intestinal contents tagging by diatrizoate meglumine for single-source dual-energy CT colonography with sequential acquisitions and volume scanning.
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Objective To study the compliance of examinees,and effectiveness of colorectal distension with partially automated and individualized insufflation of air for dual-energy CT colonography.Methods Forty-six healthy adult volunteers without history of conditions affecting gastrointestinal motor function were enrolled in this study.One day before CT examination,volunteers were asked to orally administered 60 mL 4% diatrizoate meglumine five times for fecal tagging.Air was insufflated by using an inflator in a partially automated and individualized manner.The volunteers were initially asked to assume the right lateral decubitus position,then slowly turn to the supine position.Insufflation rate began at 1.5 L/min,and decreased to 0.5 L/min at later stage.The necessity and volume of air insufflation were decided according to effectiveness of colorectal distension on CT scout images,self-reported sensation of volunteers,and intestinal pressure.Dual-energy CT scanning was performed,and dual-energy blended images were acquired.Compliance of volunteers was statistically analyzed.The effectiveness of colorectal segments distension was statistically analyzed by using Kruskal-Wallis H test.Results No abdominal pain,bloating,nausea or vomiting were noted in the 46 volunteers.All volunteers easily accepted colorectal insufflation of air,with grade 1 compliance.The effectiveness of colorectal distension of grades 1,2,3 and 4 were 0%,2.1%,5.1% and 92.8%,respectively.The difference of effectiveness of colorectal segments distension had no statistical significance(χ2=6.19,P=0.288).The effectiveness of insufflation was poor in 6 colorectal segments,including 2 in sigmoid colon and 2 in rectum.Effectiveness of insufflation was suboptimal in 14 colorectal segments,including 4 in descending colon,4 in sigmoid colon,and 3 in rectum.Conclusion Compliance of examinees with partially automated and individualized insufflation of air for dual-energy CT colonography is excellent,with good effectiveness of colorectal distension.
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<p><b>OBJECTIVE</b>To demonstrate the clinical applicability of three-dimensional CT angiography by evaluating the anatomic features and variation of inferior mesenteric artery(IMA) and left colic artery(LCA) in order to provide reference to vessel ligation strategy in laparoscopic rectal cancer surgery.</p><p><b>METHODS</b>Clinical and image data of 123 patients receiving abdominal multislice CT at The Sixth Affiliated Hospital from 2014 to 2015 were retrospectively analyzed. The images were 3D-reconstructed with computer 3D CT angiography and arterial enhancement phase images were chosen for analysis. Linear distances from IMA root to abdominal aortic bifurcation and from LCA at IMA root level to IMA root were measured. Branch types of IMA, coursing pattern of LCA, and association between LCA and inferior mesenteric vein (IMV) site were summarized.</p><p><b>RESULTS</b>Of 123 cases, 80 were males and 43 were females, mean age was (46.8±16.6) years, body weight was (57.7±10.4) kg, and BMI was (21.3±3.6) kg/m. The average distance from IMA root to abdominal aortic bifurcation was (42.5±7.9) mm, and this distance was closely associated with body weight (OR=4.771, 95%CI: 1.398 to 16.283, P=0.013). Longer distance tended to appear in the heavier patients. LCA and sigmoid artery (SA) originating from same single IMA was found in 61(49.6%) cases; LCA and SA forking at same point in 35(28.5%) cases; LCA and SA coursing together and forking afterwards in 24(19.5%) cases, and LCA disappearing in 3(2.4%) cases. In 71(57.7%) patients, LCA ascended medial to the lateral border of left kidney, while in 16(13.0%) patients, LCA arranged below the inferior border of left kidney. When the LCA site was higher and the distance from LCA to IMA root was closer [distance from LCA to IMA root level was (24.2±9.9) mm, (30.0±15.2) mm and (66.6±12.3) mm, F=83.2, P<0.001]. At the level of IMA root, LCA located medial to IMV in 21(17.1%) cases, located just lateral to IMV in 54(43.9%) cases, and located lateral and ascended far away from IMV in 48(39.0%) cases.</p><p><b>CONCLUSION</b>3D-CT angiography is non-invasive, efficient and accurate in evaluating coursing features and variation of IMA and its branches, which can provide important reference to the surgeons, promising laparoscopic surgery smooth and safe.</p>
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Objective To investigate the image quality and radiation dose of 640-slice CT coronary arteriography(CTCA) with adaptive iterative dose reduction three-dimensional (AIDR3D)reconstrucction algoritym.Methods 640-slice CTCA with auto-matic exposure was performed on 84 consecutive patients.The original image data were reconstructed with AIDR3D and the filtered back-projection (FBP)algorithms at the image postprocessing workstation.Two experienced radiologists without knowing clinical information and reconstruction algorithms independently measured and calculated the image noise,signal-to-noise ratio and contrast-to-noise ratio with AIDR3D and FBP reconstruction algorithms.The qualitative image quality was assessed by using the 4-point scale.The radiation dose was calculated based on dose-length product exported on CT scanner.The quantitative and qualitative im-age quality with two kinds of reconstruction algorithm was analyzed statistically.Results The CTCA image noise was (27.20± 4.40)HU with AIDR3D and (60.00±12.40)HU with FBP,which with AIDR3D was decreased by 46.10% than that with FBP;the signal-to-noise ratio was 21.10 ± 5.10 with AIDR3D and 11.40 ± 2.80 with FBP,which with AIDR3D was increased by 84.70% than that with FBP;the contrast-to-noise ratio was 24.70±5.10 with AIDR3D and 13.50±3.20 with FBP,which with AIDR3D was raised by 82.20% than that with FBP,the differences in 3 indexes between the two kinds of reconstruction algorithm were statistically significant(P < 0.05 ).The CTCA qualitative image quality scores of proximal,middle and distal parts with AIDR3D were (3.90±0.30),(3.70±0.50)and (3.60±0.60)respectively,which all were higher than (2.60±0.60),(2.30± 0.60)and (2.10±0.70)with FBP respectively,the differences in 3 items between 2 kinds of algorithm had statistical significance (P <0.05).The total segments which could be used to diagnose the CTCA images with AIDR3D and FBP algorithms were 1 216 segments (96.50%)and 504 segments (40.00%),respectively,the difference had statistical significance(P <0.05).The mean ef-fective radiation dose was (2.10±1.00)mSv.Conclusion 640-slice CTCA with AIDR3D reconstruction algorithm not only signifi-cantly reduces the image noise than the conventional FBP algorithm,improves the quantitative and qualitative image quality,but also decreases the effective radiation dose.