Objective To explore the feasibility of coronary computed tomographic angiography (CCTA) for obese patients with lower tube voltage (100 kV) and lower contrast media concentration (270 mgI/ml) using iterative reconstruction.Methods A total of 48 patients with body mass index greater than 30 kg/m2 were included and randomly divided into 2 groups according to random number table method.The images of the control group were obtained using iodine 370 mgI/ml, a tube voltage of 120 kV, and traditional filtered back projection (FBP) image reconstruction.Patients in the test group were injected with isotonic low concentration contrast media (270 mgI/ml), scanned with a lower tube voltage (100 kV), and adaptive iterative noise reduction image reconstruction algorithm (AIDR-3D) was used.Two experienced physicians scored the image quality in a double-blind way.Independent sample t-test was used to compare the effective dose (E), average CT values, signal to noise ratio (SNR), contrast to noise ratio (CNR), the figure of merit (FOM), image quality scores and the total iodine intake.Side effect was also evaluated.Results The subjective scores for control group and test group were not significantly different (P ＞ 0.05).The scores of two physicians were consistency (Kappa =0.88, P ＜ 0.05).The average CT values, SNR and CNR for the two groups were not significantly different (P ＞ 0.05), but the FOM of the test group was significantly higher than that of the control group (t =-9.250,-8.604,-9.158,-5.341, P ＜ 0.05).Effective dose in the test group was (1.61 ± 0.41) mSv, lower than that of the control group (t =8.373, P ＜ 0.01).The total iodine and iodine injection rate in the test group were both lower than in the control group (t =7.628, 8.480, P ＜ 0.01).The incidence of contrast mediarelated discomfort in the test group was lower than control group (x2 =18.70, 6.25, P ＜ 0.05).Conclusions For obese patients, isotonic low concentration of contrast media and low-dose CCTA could be feasible, which substantially reduce the radiation dose and iodine intake without sacrificing image quality.Trial registration Chinese clinical trial registry, ChiCTR-DPD-15007510.

Objective: To study the features of spontaneous isolated superior mesenteric artery dissection (SISMAD) by unexpected detection of renal artery dual-source CT (DSCT) imaging in hypertension patients. Methods: A total of 4107 patients with suspected secondary hypertension received renal artery DSCT examination in our hospital from 2010-03 to 2015-04 were studied and SISMAD was unexpectedly found in 12 patients. There were 3 patients with mild abdominal pain and the rest without obvious abdominal symptoms. The position and length, true and false lumens, detached tunica intimal flap and branch involvement of dissection, intestinal wall edema and ileus were recorded. Results: SISMAD in all 12 (0.3%) patients were found unexpectedly. Axial CT with post-processing technique clearly displayed the ruptured tunica intimal orifice, true and false lumens, detached intimal flap; the branches were all originated from true lumen. According to Sakamoto classification, all 12 patients were belong to Type I as the true and false lumens were with an entry and re-entry respectively, no filling defect in false lumen. The distance from orifice of dissection to root of abdominal aorta was (26.7 ± 11.3) mm and the length of dissection was (35.1 ± 11.7) mm.There were 10 patients with aneurysmal expansion with the diameter of (11.9 ± 2.5) mm. Conclusion: Unexpected detection of SISMAD by renal artery CT imaging was about 0.3%, radiologist should pay special attention to find superior mesenteric artery dissection in hypertension patients.

Objective To investigate the feasibility of low-c oncentration iso_osmolar contrast agent together with low tube voltage and iterative reconstruction algorithm in rabbit liver computed tonography (CT) perfusion imaging.Methods A total of 15 bealthy New Zealand rabbits were scanned twice of liver CT perfusion scans each with 24 hours interval.The first scan (routine group) was acquired at 100 kV and 100 mAs with ultravist (370 mg/ml),while the second (double low group) was acquired at 80 kV and 100 mAs with iodixanol (270 mg/ml) at 24 hours after the first scan.The obtained images were reconstructed with filtered back projection (FBP) and adaptive iterative dose reduction (AIDR-3D)algorithms in the controlled and experimental groups,respectively.The perfusion parameters including hepatic artery perfusion(HAP),portal vein perfasion(PVP),hepatic perfusion index(HPI),and total liver perfusion(TLP) and image quality as image quality score,average CT value of abdomen aorta,signalto-noise ratio(SNR),carrier-to-noise ratio(CNR),and figure of merit(FOM) were compared used pair ttest or Mann-Whitney U-test between the two groups wherever appropriate.The effective radiation dose and iodine intake were also recorded and compared.Results The image quality and perfusion parameters had no significantly different between the two groups except for FOM.The effective radiation dose and iodine intake were 38.79％ and 27.03％ lower in the double low group.Conclusions Low concentration iso _osmolar contrast agent (iodixanol,270 mg/ml) together with low tube voltage (80 kV) helps to reduce radiation dose and iodine intake without compromising perfusion parameters and image quality in liver CT perfusion imaging.

Adult ; Humans ; Male ; Mediastinal Cyst

To explore the pharmacogenomic markers that affect the platinum-based chemotherapy response in non-small-cell lung carcinoma (NSCLC), we performed a two-cohort of genome-wide association studies (GWAS), including 34 for WES-based and 433 for microarray-based analyses, as well as two independent validation cohorts. After integrating the results of two studies, the genetic variations related to the platinum-based chemotherapy response were further determined by fine-mapping in 838 samples, and their potential functional impact were investigated by eQTL analysis and in vitro cell experiments. We found that a total of 68 variations were significant at P < 1 × 10^-3 in cohort 1 discovery stage, of which 3 SNPs were verified in 262 independent samples. A total of 541 SNPs were significant at P < 1 × 10^-4 in cohort 2 discovery stage, of which 8 SNPs were verified in 347 independent samples. Comparing the validated SNPs in two GWAS, ADCY1 gene was verified in both independent studies. The results of fine-mapping showed that the G allele carriers of ADCY1 rs2280496 and C allele carriers of rs189178649 were more likely to be resistant to platinum-based chemotherapy. In conclusion, our study found that rs2280496 and rs189178649 in ADCY1 gene were associated the sensitivity of platinum-based chemotherapy in NSCLC patients.