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Objective: To investigate the value of the multiple model parameters of intravoxel incoherent motion (IVIM) in identification of stage endometrial carcinoma (EC) and endometrial polyp (EP). Methods: The clinical and imaging data of 31 patients with stage EC (group EC) and 14 patients with EP (group EP), confirmed by postoperative pathological examination, were retrospectively analyzed, all patients were performed on 1.5T MR (including IVIM sequence, b=0, 20, 50, 100, 150, 200, 400, 800, 1 200, 2 000, 3 000 s/mm2) before operation. The IVIM multi-model parameter values of the lesions were measured and compared between the two groups, including the standard apparent diffusion coefficient (ADC-stand), slow-apparent diffusion coefficient (ADC-slow), fast-apparent diffusion coefficient (ADC-fast), perfusion fraction (f), distributed diffusion coefficient (DDC) and water molecular diffusion heterogeneity index (α). The ROC curve was used to evaluate the differential diagnostic efficacy of IVIM parameters for stage EC and EP. Results: The ADC-stand value, ADC-slow value, f-value, DDC value and α value of the EC group were all less than the EP group, and the ADC-fast value was greater than the EP group (all P=0.001). ROC curve results showed the standard ADC value, ADC-slow value, ADC-fast value, f value, DDC value and α value had differential diagnostic value for stage EC and EP, the AUC was 0.885, 0.877, 0.919, 0.926, 0.906 and 0.902, respectively (all P<0.05). Conclusion: The multi-model parameters of IVIM sequence can effectively identify stage EC and EP.
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Purpose To explore the feasibility of denoising algorithm-PixelShine algorithm based on deep learning to enhance the quality of abdominal arterial phase CT images rebuilt by 70 kVp combined with adaptive statistical iterative reconstruction-Veo (ASiR-V). Materials and Methods Abdominal arterial phase images of 33 patients [body mass index (BMI) BMI≤20 kg/m2] scanned by GE Revolution CT were retrospectively analyzed (group A) using 70 kVp tube voltage and 50% ASiR-V technique. PixelShine algorithm B2 mode was applied to post-process group A images to obtain PixelShine image (group B). Two observers rated the image quality of the two groups via a 5-point rating system. The consistency of the rating was analyzed. The difference in ratings, noise, virtual signal-to-noise ratio (SNR) of liver and pancreas and contrast noise ratio (CNR) were compared between the two groups of images. Results The image quality rating of group A and B were(3.12±0.33) scores and(3.97±0.53) scores respectively,noise value(14.50±1.42)HU vs(10.05±1.80)HU, liver virtual SNR 4.51±0.53 vs 6.78.±1.27,liver virtual CNR 0.89±0.55 vs 1.42±0.81,pancreatic virtual SNR 9.51±1.69 vs 13.87±3.26, and pancreatic virtual CNR 5.83±1.66 vs 8.48±2.46.The quality rating of images,liver and pancreas virtual SNR,CNR in group B were all higher than those in group A, and the image noise of group B decreased about 31% compared with that of group A, the difference was statistically significant (P<0.05). Conclusion Post-processing with PixelShine algorithm can improve the image quality of 70 kVp abdominal arterial phase, significantly reduce image noise, and increase image SNR and CNR.
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Objective To assess the value of spectral CT imaging in distinguishing mass type colorectal adenocarcinoma from colorectal adenoma. Methods Forty patients underwent preoperative abdominal dual energy spectral CT scan were analyzed restrospectively, including 17 with colorectal adenomas and 23 with mass type colorectal adenocarcinomas proven by endoscopic and surgical pathology. All patients underwent plain and three-phase enhanced CT scanning. The conventional polychromatic CT value and its pre- and postcontrast CT values, monochromatic CT value of 40 to 100 keV, the slope of spectral curve and iodine(water) concentration were measured, and the maximum diameter of the lesion was recorded. The maximum diameters of the lesions and imaging parameter differences between the adenomas and adenocarcinomas in plain and three-phase enhanced scan were analyzed with independent sample t tests. The data of the parameters with significant differences were further analyzed by ROC curves. Results The maximum diameters of the adenomas and mass type adenocarcinomas were (1.97 ± 0.54), (2.32±0.53) cm respectively, and there was no statistically significant difference (t=-2.011, P=0.051). There was no statistically differences of the conventional polychromatic CT value and its pre-and postcontrast CT values between the two groups in 4 phases (P>0.05). However, in the arterial phase, the CT values of adenomas were significantly lower than those of adenocarcinomas at low (40, 50 keV) energy (P0.05). The slope of spectral curve and the iodine(water) concentration both showed significant differences in the arterial phase between the two groups (P0.05).The largest area under the ROC curve of the iodine(water) concentration in the arterial phase was 0.757 in differentiating adenomas and mass type adenocarcinomas, with sensitivity of 73.9%and specificity of 82.4%at the cut-off of 21.02 mg/cm3. Conclusion Spectral CT imaging is valuable in differentiating colorectal adenoma from mass type colorectal adenocarcinoma with the parameters of the arterial phase.
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Objective To investigate the value of diffusion kurtosis imaging (DKI)quantitative parameters in evaluating patholog-ical grade of cervical squamous cell carcinoma (CSCC).Methods The DKI images of 45 patients with CSCC were analyzed retrospec-tively.According to the results of pathology,22 cases were divided into poorly differentiated group and 23 cases well-moderately dif-ferentiated group.The DKI parameters of two groups were measured by two observers,which included mean kurtosis (MK),axial kurtosis (Ka),radial kurtosis (Kr),fractional anisotropy of kurtosis (FAk),mean diffusivity (MD),axial diffusivity (Da),radial diffusivity (Dr)and fractional anisotropy (FA).The intra-class correlation coefficients (ICC)was used to test the consistency of the parameters measured results on two observers.The two independent samples t test was used to compare the parameters of two groups,and the ROC curve was used to evaluate the effectiveness of each parameter in order to evaluate the poorly differentiated CSCC and find the boundary values.Results The data consistency of two observers were good (ICC>0.75).The MK,Ka and Kr values on poorly differentiated CSCC were greater than that on well-moderately differentiated (P0.05).Thearea un-der curve (AUC)of MK,Ka,Kr,MD,Da and Dr values to diagnose poorly differentiated CSCC were 0.914,0.831,0.865,0.850, 0.778 and 0.865,respectively.The boundary values of diagnosing poorly differentiated CSCC were MK≥0.973,Ka≥1.075,Kr≥0.823, MD≤0.974μm2/ms,Da≤1.185μm2/ms and Dr≤0.762μm2/ms,respectively.Conclusion DKI can effectively predict the patho-logical grading of CSCC,which has a good clinical application prospects.
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Purpose To explore the influence of duration of scan acquisition on perfusion parameters in whole renal perfusion with Revolution CT.Materials and Methods Fortytwo patients without pathologic changes in bilateral kidneys were divided into group A (with short perfusion time) and group B (with long perfusion time) according to the duration time of the perfusion scan.The Revolution CT axial scan mode was used for perfusion scan,and the width of detector was 16 cm.The perfusion CT series were performed in 50 seconds,each comprising 25 volumes with identical parameters (80 kVp,200 mA) in group A.The perfusion CT series were performed in 594 seconds,each comprising 23 volumes with identical parameters (120 kVp,55 mA) in group B.The source datasets were post-processed with CT Perfusion 4D software,and the perfusion parameter maps were obtained when right renal abdominal aorta was taken as entry artery.Perfusion parameters of bilateral kidneys were compared within and between group A and group B,respectively.CT dosage index of volume (CTDIvol) and dose length product (DLP) were recorded.The effective dose (ED) was calculated and compared.Results There were no statistical difference in all parameters between bilateral kidneys within each group (P＞0.05).However,blood volume,time to peak,and permeability surface in the cortex and medulla of bilateral kidneys all showed differences between the above two groups (P＜0.05).The mean transit time in the medulla between the two groups was different (P＜0.05),but neither the blood flow in the medulla and cortex nor the mean transit time of the cortex had difference between the two groups (P＞0.05).The effective radiation doses were (23.10± 4.39)mSv in group A and (23.19±0.00) mSv in group B,respectively (without statistic difference:P＞0.05).Conclusion CT perfusion parameters with different duration time show differences in whole renal perfusion;therefore,scanning time needs to be set according to the clinical application.
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Objective To evaluate the feasibility of multi-parameter MRI in diagnosing ovarian endometrial cysts. Methods Pelvic MRI of 68 patients with confirmed pathological diagnosis were retrospectively reviewed. The patients were divided into ovarian endometriosis (35 patients with 42 lesions, group A) and other cystic lesions (33 patients with 38 lesions , group B).The signal intensity value of T1WI, T2WI of cyst fluid and iliopsoas, ADC value, phase values and R2*values were obtained, cyst fluid/iliopsoas ratios (T1R and T2R) were calculated. The non-parametric Mann-Whitney U test was employed to compare parameter values between the two groups. The values of diagnostic performance were analyzed by using receiver operating characteristic curve (ROC). Use the Logistics regression parameters of diagnostic efficacy to select the highest Youden index for the best parameter association after combining the parameters step by step. Results The median of T1R, T2R, ADC, phase, T1R and R2*values for group A were 3.39, 5.28, 1.20×10-3 mm2/s,2.19×10-2, 15.08 Hz respectively, and that of group B were 0.91, 10.85, 2.64×10-3mm2/s,2.67×10-2, 3.01 Hz, respectively. There were statistically significant difference between the two groups (P0.05). When combining T1R, ADC value, R2*value together, the Youden index (0.849 7) was highest. Conclusion Combining T1R, ADC and R2* values can provide an effective way to discriminate endometrial ovarian cyst from other ovary cystic lesions.
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PurposeTo investigate the effects of the low concentration contrast medium combined with optimal single source spectral imaging on displaying feeding arteries of gastrointestinal tract malignant tumors.Materials and Methods Seventy-one patients of body mass index (BMI) >25 kg/m2 with gastrointestinal tract malignant tumors were prospectively studied. All the cases were randomly divided into two groups: high concentration group (33 cases with high concentration contrast medium of 350 mgI/ml in routine scan) and low concentration group (38 cases with low concentration contrast medium of 270 mgI/ml in optimal single source spectral imaging). The optimal single source images were generated automatically. The subjective image scores, CT value of the tumor feeding arteries, image noise, contrast-to-noise ratio (CNR) and CT dose index of volume (CTDIvol) of optimal single source spectral images in two groups were compared. Results The optimal single source of low concentration group were 51-60 keV. The subjective image score of low concentration group was higher than high concentration group (Z=-4.280,P0.05).Conclusion The low concentration contrast medium with optimal single source spectral imaging in patients with large BMI may improve CTA image quality of feeding arteries of gastrointestinal tract malignant tumors without increasing radiation dose.
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Objective To explore the application value of optimal energy imaging technique of monoenergetic dual-energy computed tomography (DECT) in feeding arteries examination of rectal cancer.Methods The clinical data of 33 patients with rectal cancer who were admitted to the First Affiliated Hospital of Dalian Medical University from July 2012 to July 2014 were analyzed retrospectively.The polychromatic and monochromatic images of feeding arteries of tumors were reconstructed and evaluated using a subjective image quality score of 5-point scale by 2 observers.The consistency and scores of evaluation were analyzed by the κ test and MannWhitney U test.The CT value of feeding arteries of tumors and hip muscle,image noise and contrast to noise ratio (CNR) were measured and calculated by 2 observers,and were compared by the independent sample t test.The consistency of data between the 2 observers were measured by the intra-class correlation coefficients (ICC).Results Inferior mesenteric arteries were contributor of blood supply of tumors in all the 33 patients,including 4 cases with right inferior rectal artery as contributor of blood supply of tumors,2 cases with bilateral inferior rectal artery.Among patients with abnormal blood vessels,there were 8 patients with left colic artery and sigmoid artery having common trunk,4 patients with left colic artery originated from Inferior mesenteric artery,1 patient with absence of left colic artery.The 0-,1-,2-,3-,4-score polychromatic image quality of feeding arteries of tumors were detected in 0,13,13,5,2 patients and 0,11,14,6,2 patients by 2 observers,respectively.The 0-,1-,2-,3-,4-score monochromatic image quality of feeding arteries of tumors were detected in 0,0,7,7,19 patients and 0,0,6,9,18 patients by 2 observers,respectively.Good interobserver agreement was found for the evaluation of subjective scores (κ =0.864,0.897).The subjective scores of image quality of feeding arteries in the polychromatic images and in the monochromatic images were 1.9 ± 0.9 and 3.4 ± 0.8,with significant difference (Z =-5.21,P ＜ 0.05).The latter was superior to the former.The ICC values of the CT values of feeding arteries of tumor,hip muscle,image noise and CNR were 0.953,0.907,0.839,0.964 and 0.966,0.933,0.952,0.962 from the 2 observers,with a good consistency.The CT values of feeding arteries of tumor,gluteal muscles,image noise and CNR in the polychromatic images and in the monochromatic images were (234 ± 52)HU and (412±83)HU,(57±9)HU and (71 ±15)HU,(21 ±3)HU and (31 ±6)HU,9 ±3 and 11 ±4,respectively,with significant differences (t =-18.65,-4.44,-14.14,-6.55,P ＜ 0.05).The levels of monochromatic images of 33 patients were 51-61 keV,with a median of 55 keV.Conclusion The optimal energy imaging technique of monoenergetic DECT can improve the angiographic quality of feeding arteries in patients with rectal cancer.
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Purpose To investigate the effect of low contrast dose and low tube voltage combined with adaptive statistical iterative reconstruction (ASIR) on image quality of abdominal CT angiography. Materials and Methods 139 patients with body mass index (BMI) 0.80) in both groups, the subjective score of group A and group B were 4.60±0.51 and 3.81±0.76, respectively, and the difference was statistically significant (Z= - 6.86, P0.05). The total amount of iodine dose in group A and group B was 270 mg and 350 mg respectively, with a 22.86% reduce of the total iodine for each patient in A group than in B group. Conclusion For patients with BMI<22 kg/m2, it is feasible to use low dose contrast medium with low tube voltage and ASIR, which may not only improve the image quality of abdominal CTA but also reduce the radiation dose and iodine content.