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Objective:To evaluate the clinical application of three dimensional artificial intelligence(3D-AI) localization technology in chest CT scan.Methods:A total of 100 patients who underwent chest CT for COVID-19 screening in Nanjing University Medical School Affiliated Drum Tower Hospital were collected from September 2020 to October 2020 were analyzed retrospectively. The patients were divided into manual positioning group ( n=50) and 3D-AI automatic positioning group ( n=50) with block randomization method. All patients were scanned with the same CT scanning protocol. The off-center distance, CT dose index (CTDI), dose length product (DLP) and CT examination time were measured and recorded. Quantitative image evaluation of mediastinal window images and qualitative image evaluation of chest window images were assessed by two radiologists. The off-center distance, CTDI, DLP, CT examination time and objective indexes of image quality of two groups were compared by independent sample t test. The quantitative image quality scores were compared with χ 2 test. Results:Compared with manual positioning group, the overall off-center distance of 3D-AI automatic positioning group was reduced by 42.86% [(15.4±9.7) vs. (8.8±7.2)mm, t=3.65, P<0.01], CTDI was reduced by 10.67%[(7.5±2.5) vs. (6.7±2.6)mGy, t=0.59, P=0.04], DLP was reduced by 13.33%[(270±95) vs. (234±86)mGy·cm, t=1.98, P=0.02], the average examination time was reduced by 29.91% [(214±26) vs. (150±14)s, t=15.79, P<0.01]. There were no significant differences in the background noise, signal to noise ratio of descending aorta and erecting spinal muscle, and subjective score between two groups ( P>0.05). Conclusion:The 3D-AI automatic positioning technology can greatly improve the accuracy of patient positioning and reduce the radiation dose for chest CT imaging, and improve work efficiency with qualified chest CT image quality.
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In order to conceal the unpleasant smell of pharmaceutical raw materials of penicillin V potassium, we use Beta-cyclodextrin [Beta-CD] as a drug carrier. The Penicillin V potassium Beta-CD inclusion complex was prepared by saturated aqueous solution method; the characterization of penicillin V potassium Beta-CD inclusion complex is determined by scanning electron microscopy, Differential Scanning Calorimeter [DSC] and X-ray Diffraction [XRD], the formation constants of the complexes were determined by UV spectrophotometry; based on the results obtained from the orthogonal experimental design, the optimum preparation process are summarized as follow: Beta-CD: Penicillin V potassium = 4: 1 [molar ratio], stirring temperature 50 centigrade, strirring time 12h, the encapsulation efficiency is 29.40%
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Objective To investigate the effect of magnifying endoscopy with narrow-band imaging (ME-NBI) in diagnosis of early gastric neoplastic lesion. Methods 151 patients with suspected gastric cancer underwent endoscopic examination in digestive endoscopy center from January 2013 to June 2016 were enrolled the study. They firstly received conventional white light endoscopy (WLE), then ME-NBI (including intervening part) and targeted biopsy. And all patients were divided into early cancer group (high grade intraepithelial neoplasia, intramucosal carcinoma and submucosal carcinoma, n = 72) and non-early cancer group (low grade intraepithelial neoplasia, n = 79). The area under receiver-operating characteristic curve (AUC) was performed to evaluate prognostic value of each index in early cancer. Results The incidences of the demarcation line, irregular microvascular pattern, irregular microsurface pattern and increasing intervening part in early cancer group were significantly higher than that in the non-early cancer group (P < 0.05). The AUC of ME-NBI for early gastric cancer was 0.947 and higher than 0.832 of WLE. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and Youden index were 97.2%, 84.8%, 85.4%, 97.1% and 0.820, respectively. The AUC of intervening part for early gastric cancer was 0.907 and higher than 0.889 of the traditional VS classification, and AUC, sensitivity, specificity, PPV, NPV and Youden index of VS type combined with intervening part were 0.933, 95.8%, 83.5%, 84.1%, 95.7% and 0.794, respectively. Conclusions ME-NBI is an important method for diagnosis of early gastric cancer, and intervening part has the advantages of strong objectivity, simple and easy to operate, good repeatability, and it could be used to assist traditional VS classification in judging the nature of lesions.
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Objective To study the curative effect of endoscopic dilatation in children with benign esophageal stricture. Methods 98 patients with benign esophageal stenosis from June 2013 to June 2016 were selected as the subjects of group A, group B and group C, 11 patients in group A were reflux esophageal stenosis, 43 children in group B were congenital esophageal atresia and in group C were 44 patients with chemical burn esophageal stricture. Then compare the three groups of children before the expansion of stenosis before the situation, the number of expansion and complications occurred. Results There was no significant difference in the average diameter of stenosis among the three groups (P > 0.05). The average length of the children in group C was higher than that in group A and group B, and group B was higher than group A, the difference was statistically significant (P > 0.05). The average number of expansion in group C was higher than that in group A and group B, and group B was higher than that in group A and group B higher than group A, the difference was statistically significant (P 0.05). Conclusion Endoscopic dilatation has a good clinical effect on children with benign esophageal stricture, but children with chemical burn esophageal stricture need to be expanded more often, while the complications are higher and the treatment is more difficult.
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Objective To evaluate the feasibility of low-tube-voltage, low injection rate, low contrast agent dosage in combination with iterative model reconstruction ( IMR) algorithm in CT angiography ( CTA) of the head-and-neck vessels .Methods Sixty patients who underwent CT angiography of the head-and-neck vessels were randomly divided into groups A and B with 30 cases in each group .Patients in group A received a conventional scan with 120 kVp and filterback projected ( FBP) reconstruction .Patients in group B received a low-dose scan with 80 kVp, and image reconstruction with FBP ( group B1) and IMR (group B2)algorithm.The contrast agent protocol were as follows: the injection time in all patients was 10s, the injection rate was 4.5-5.5 ml/s in group A while 3.5-4.0 ml/s in group B.The CT values of artery, image noise, signal to noise ratio ( SNR) and contrast to noise ratio ( CNR) were measured and compared among three groups with One-way ANOVA analysis . Image quality was evaluated by two radiologists with five scale method , and compared with Kruskal-Wallis test .The CT dose index volume (CTDIvol) and dose length product ( DLP) were recorded and compared between groups with two independent samples t-test.Results The image quality scores of groups A , B1and B2 were 3-5, 2-4 and 3 -5, respectively .Image quality of twelve patients in group B 1 couldn′t meet the diagnostic requirements but none in group A and B 2.The objective image parameters SNR and CNR for group B 2 were equal to group A ( P >0.05), while those for group B1 were lower than group A (t=13.39, 9.45, P<0.05) and group B2 (t=-12.14, -9.96,P<0.05).CTDIvol and DLP for group B were separately 80.9%, 81.3%lower than those of group A(t=39.1, 32.2,P<0.05).The injection rate and contrast agent volume for group B were separately 22.0%, 22.1% lower than those of group A ( t=20.8, 20.8, P<0.01) .Conclusions It is feasible in CT angiography of the head-and-neck vessels with lower tube-voltage, lower injection rate, lower contrast agent dose and combining with iterative model reconstruction algorithm.This protocol can reduce the radiation dose by 81.3% while maintaining image quality .Trial registration Chinese clinical trial registry ,ChiCTR-BOC-16010060.
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Objective To investigate the feasibility of setting mAs in liver enhanced CT scan according to plain scan noise with fixed mA CT scanner,in order to reduce the radiation dose.Methods One hundred continuous patients underwent liver enhanced CT scan (group A) prospectively.Two hundred and fifty mAs was used in plain and enhanced CT scans.Noises of plain and venous phase CT images were measured,and the image quality was evaluated.The equation between mAs of enhanced scan and noise of plain scan image was derived.Another 100 continuous patients underwent liver enhanced CT scan (group B).Enhanced scan mAs was calculated from noise on plain scan by using the equation above.Noises on venous phase images were measured and the image quality was measured.Based on body mass index (BMI),patients in groups A and B were divided into three subgroups respectively:BMI ＜ 18.5 kg/m2,18.5 kg/m2 ≤ BMI ＜ 25.0 kg/m2 and BMI ≥ 25.0 kg/m2.Image quality score was compared with nonparametric rank sum test,CT dose index (CTDI) and effective dose (ED) were measured and compared between each subgroup with 2 independent samples t or t' test.Results The equation between enhanced scan mAs (mAsX) and plain scan noise (SDp) was as follows:mAsX =mAs1 × [(0.989 × SDp + 1.06) /SDx]2,mAs1 =250 mAs,SDx =13.In patients with BMI ＜ 18.5 kg/m2,ED of group A [(6.86 ±0.38) mSv,n =12] was significantly higher than group B [(2.66 ±0.46) mSv,n =10)] (t =18.52,P ＜0.01).In patients with 18.5 kg/m2 ≤ BMI ＜ 25.0 kg/m2,ED of group A [(7.08 ± 0.91) mSy,n =66] was significantly higher than group B [(4.50 ± 1.41) mSv,n =73] (t' =10.57,P ＜ 0.01).In patients with BMI ≥25.0 kg/m2,there was no significant difference between EDs of group A (7.54 ± 0.62 mSv,n =22) and group B [(8.19 ±3.16) mSv,n =17] (t' =0.89,P =0.39).Image quality of 5 patients in group A and none in group B did not meet the diagnostic requirement.Conclusion Setting mAs of enhanced scan according to plain scan noise could reduce the radiation dose with maintainence of image quality.