Objective To compare the conventional non-enhanced and virtual non-enhanced images of dual-energy computed tomography (CT) in evaluating solitary pulmonary nodules (SPNs).Methods Forty-seven patients with SPNs proved by pathology underwent conventional and enhanced thoracic DECT.The virtual non-enhanced CT images and iodine images were reconstructed based on the enhanced imaging data.The mean CT number,noise,signal to noise (SNR),nodual diameter of SPNs were compared between the true non-contrast CT(TNCT) and the virtual non-contrast CT (VNCT),with paired t test.The image quality and detectability of calcification were also compared.The diagnostic accuracy for malignant nodulesbased on the increased CT values and iodine-enhanced image were compared.The independent t test was used to compare the increased CT number of SPNs and iodine images.The single-phase radioation dose of the single energy,was compared with dual energy scan.Results No significant difference in the mean CT Number(t =1.556,P ＞ 0.05),noise (t =-0.357,P ＞ 0.05),SNR (t =0.767,P ＞ 0.05) on TNCT and VNCT.The mean CT Number,the noise,and SNR were (29.90 ± 12.43)vs (27.52 ± 16.67) HU,(9.60 ±3.74) vs (9.88 ± 2.90),and (3.07 ± 1.93) vs (2.76 ± 2.36),respectively.The increased CT number ofSPNs with TNCT and VNCT from baseline were(18.63 ± 8.03) and(20.45 ± 9.13) HU.The CT number of iodine image was(23.82 ± 9.20)HU.A significant difference was observed between the TNCT and iodineed image (t =-2.371,P ＜ 0.05).The quality scores of VNCT image wasslightly worse than TNCT image.The detectability rate of calcification on VNCT was 92.3％ (72/78).The iodine image carried the highest diagnostic sensitivity rate and accuracy rate,82.3％ (28/34)and 74.5％ (35/47),respectively.The highest specificity rate was 76.9％ (10/13) from the increased CT number with VNCT.No significant difference in single-phase radiation dose was observed between TNCT and VNCT,(5.68 ± 1.31) vs.(4.89 ± 1.27)mSv.Conclusions VNCT could be obtained with similar image quality as TNCT.This methods might favor a reduction in radiation exposure.

Purpose To explore the diagnostic value of multiple image technique derived from dual-energy CT in arterial+parenchymal phase scan mode in detecting pancreatic adenocarcinoma so as to provide more valuable information for clinical treatment.Materials and Methods Thirty two patients with pancreatic adenocarcinoma proved pathologically underwent dual-phase scan with dual-source CT.Linear blend image,non-linear blend image and iodine map were acquired.The absolute enhancement value of tumor (AEV),the relative enhancement value of tumor (REV),enhancement ratio (ER) of tumor to pancreatic parenchyma,and the image contrast to noise ratio (CNR) were also calculated,so that the diagnostic value and the ability image in two phases to display the pancreatic adenocarcinoma lesions could be assessed.Results On arterial phase,the differences in AEV,REV and CNR value were significant among the three groups images (P＜0.05).On parenchymal phase,the difference in REV,ER,and CNR value were also significant among the three groups (P＜0.05).When the three sequences on the 2 phases were compared with each other,the differences in AEV and REV value of tumor tissues were significant among the groups (P＜0.05).Moreover,the differences of ER value in linear blend image and CNR in the iodine map were significant in dual phase enhancement (P＜0.05).Conclusion Dualenergy CT enhanced scan mode on dual phase combined with multiple sequences can improve the sensitivity in detection of pancreatic adenocarcinoma lesions.

Objective To analyze CT manifestation of Schistosoma haematobium cystitis.Methods Retrospective analysis 32 patients,who were tested for Schistosoma haematobium cystitis using the urine filtration method.CT scan was performed for each patient with contrast enhancement.Results The vast majority of urinary tract schistomiasis lesions were in the urinary bladder.Calcification of the bladder wall was observed in all patients and mild enhancement in non calcified zone was found after intravenous contrast.Except for 5 patients of bladder cancer,the rest were no abnormality in size of bladder when bladder was filling or emptying.Ureteral wall annular calcification could also be identified in 25 patients.Twenty two patients were companied with ureteric hydronephrosis.Seminal vesicle calcification was seen in 4 patients among 11 male patients,while both uterine and ovarian in female and prostate in men had non calcification.Serious illness can be combined with bladder cancer.In 5 patients of patients with bladder cancer,bladder showed irregular soft tissue mass which was enhanced moderately after post-contrast scan,with vesical calcification in mass medially.Conclusion Bladder calcification is the most prominent CT feature of Schistosoma haematobium cystitis,which is useful in diagnosis the disease.

Objective To evaluate the clinical value of multi-slice spiral CT (MSCT)in the screening of coronary artery lesions in elderly patients with diabetes mellitus.Methods MSCT and coronary angiography(CAG)were performed in 136 elderly patients(68 patients with diabetes and 68 patients without diabetes).The number of diseased coronary segments and the plaque type (noncalcified,mixed and calcified)for each patient were determined.The characteristics of coronary lesions were compared between patients with and without diabetes.The sensitivity and specificity of MSCT were evaluated.Results More noncalcified and calcified plaques and few ermixed plaques were observed in patients with diabetes,compared with patients without diabetes(noncalcified plagues:10 cases or 14.7％ vs.4 cases or 5.9％;calcified plagues:47 cases or 69.1％ vs.39 cases or 57.4％)(P＜ 0.05).In addition,diabetic patients showed a significantly higher frequency of multivessel disease(P＜0.05).Furthermore,MSCT was able to clearly show stenosis and plaque type in the trunk and branches of the coronary artery,with a sensitivity of 91.0％,a specificity of 95.0％,a positive predictive value of 93％ and a negative predictive value of 96.0％.Conclusions Diabetes is associated with a higher risk of coronary artery disease.MSCT can effectively detect the characteristics of coronary artery disease in diabetic patients and is an effective,noninvasive,and safe screening method.