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Objective To explore the correlation between apparent diffusion coefficient (ADC) and pathological grading and staging of cervical carcinoma.Methods Among 311 patients diagnosed with squamous cell carcinoma,87 patients were met the criteria for inclusion.All the patients were performed routine MR and diffusion-weighted imaging(DWI) with b=1 000 s/mm2 before treatments,and recorded the pathological grading and staging.The ADC values of the lesions were measured on GE AW4.5 workstation,and were compared among the groups with different pathological grading and staging by using LSD and paired t-test.Results The mean ADC value was (0.77±0.079)×10-3 mm2/s in the poorly-differentiated group,(0.88±0.10)×10-3 mm2/s in the moderately-differentiated group,and (1.05±0.084)×10-3 mm2/s in the well-differentiated group.There were significant differences among the different groups (P0.05).Conclusion The increasing of the ADC values is correlated with the high levels of tumor cell differentiation, and not correlated with the pathological stages in cervical carcinoma.
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Objective To explore the value of spectral CT imaging in the preoperative evaluation on histodifferentiation of rectal adenocarcinoma.Methods 90 patients with rectal adenocarcinoma underwent dual-phase enhanced spectral CT scan,and were divided into well,moderately and poorly differentiated adenocarcinoma groups according to the pathology.Single-energy images with energy levels from 40 to 140 keV were generated by GSI Viewer software,and the slope K value of the energy curves were calculated.Iodine concentrations were derived from iodine-based material-separation images and normalized to the iodine concentrations in the aorta. ROC curves were derived to evaluate the differentiation diagnosis efficiency of normalized iodine concentration (NIC)and slope K in rectal adenocarcinoma,respectively.Results There were 22,50 and 18 cases in the well,moderately and poorly differentiated group,respectively.The iodine concentration,NIC and slope K value were statistically different both in the arterial and venous phase (P76% and the specificity>74% in the arterial phase,and the sensitivity>77% and the specificity>70% in the venous phase by choo-sing the appropriate threshold.Conclusion The spectral CT can provide a new method for preoperatively evaluating the histodiffer-entiation of rectal adenocarcinoma.
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Purpose To explore the feasibility of optimizing monochromatic images in reducing iodinated contrast dose in CT pulmonary angiography (CTPA). Materials and Methods Sixty-eight patients undergoing CTPA were randomly divided into two groups, with half in research group and half in conventional group to evaluate image quality. Research group underwent spectral CT imaging with the injection of 30 ml Omnipaque (300 mgI/ml) and optimal monochromatic images were postprocessed using the software of GSI viewer. Conventional group underwent conventional CTPA with the injection of 80 ml Ultravist (370 mgI/ml). The CT values were measured respectively in the main pulmonary artery, left pulmonary trunk, right pulmonary trunk, left lobe artery and right lobe artery. The contrast noise ratio (CNR) in two groups were calculated, and image quality were subjectively assessed. Results The total iodine intake in research group (9000 mg) was significantly lower than that of conventional group (29 600 mg). CNR in the main pulmonary artery, left pulmonary trunk, right pulmonary trunk, left lobe artery and right lobe artery in research group was significantly higher than that of conventional group (t=2.07-2.71, P0.05), while there was a good agreement between the two readers (Kappa=0.8, P<0.05). Conclusion It is possible to reduce iodinated contrast dose using spectral CT imaging and improve the image quality of CTPA.
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Objective To evaluate the value of low concentration of isotonic contrast agent combined with 80 kV and adaptive statistical itera-tive reconstruction (ASiR)technique for bronchial artery with CT angiography (CTA).Methods 40 patients (18.5 kg/m2 ≤ body mass index(BMI)≤25 kg/m2 )with lung cancer were randomly divided into two groups and performed enhanced chest CT examina-tion.20 patients (low concentration group)were scanned with Visipaque 270mg I/mL,scanning protocol of (80 kV,260 mA)and other 20 patients (high concentration group)were scanned with Ultravist 370 mg I/mL,scanning protocol of (120 kV,1 50 mA). The CT value,signal noise (SD),signal-to-noise ratio (SNR),contrast-to-noise ratio (CNR)and effective dose (ED)of the two groups were compared and analyzed statistically.Differences between the two groups were determined with t test(P <0.05).Results The mean CT value of the low concentration group (31 7.33 HU±70.44 HU)was higher than that of the high concentration group (256.39 HU±37.38 HU)(P <0.05).SD,ED and dose length product (DLP)of the low concentration group (SD:7.55 ±1.51 HU;ED:1.74±0.14 mSv;DLP:124.94±9.9 mGy/cm)were lower than those of the high concentration group (SD:9.36±1.26 HU;ED:3.20±0.35 mSv;DLP:228.82±25.13 mGy/cm)(P <0.05).CNR and SNR of the low concentration group (CNR:59.71± 17.36;SNR:44.01±14.71)were higher than those of the high concentration group (CNR:37.61±6.16;SNR:27.75±4.72)(P <0.05).The subjective scores of the two groups were (3.73±0.66)and (3.81±0.59),respectively,with no statistical difference.Conclusion For the patients with normal body mass index ,it can reduce 47% radiation dose and 27% iodine dosage using low concentration of isotonic contrast agent combined with 80kV and ASiR technique for bronchial artery CTA,while maintaining similar excellent image quality.
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Objective To investigate the optimal monochromatic parameters of CT angiography (CTA) on small feeding arteries of abdominal tumors using single source dual-energy CT with gemstone spectral imaging (GSI) technique.Methods The clinical and medical imaging data of 32 patients with abdominal malignant tumor were analyzed retrospectively during January to April 2012.Three phase-enhanced CT scans (Discovery CT750 HD,GE Heahhcare,Milwaukee,USA) of the abdomen were recorded using the GSI technique on 32 patients.The minor feeding arteries of tumor with diameter between 1.5 mm to 3.0 mm were reconstructed by 140 kVp mixed energy,66 keV,and optimal monochromatic mode respectively.After CT scanning,the original data were processed with layer and interval of 0.625 mm,the 140 kVp mixed energy images and 70 keV monochromatic images were obtained with standard algorithm.The original images were conveyed to AW4.5 work-station to process furthermore,then the data of the optimal monochromatic group and 66 keV group were reconstructed.Comparative parameters include contrast-to-noise ratio (CNR),signal-to-noise ratio (SNR) and subjective scores of the small feeding arteries CTA quality.Subjective scores were evaluated by two radiologists according to the sharpness and resolution of the small feeding arteries.One-way ANOVA was used to for statistical analysis.Results CNR of the optimal monochromatic group,the 66 keY group,and the 140 kVp mixed energy group were 21.70 ±9.74,16.63 ±7.60,and 9.85± 6.76,respectively.SNR were 35.05 ± 17.75,26.77 ± 11.51,and 16.32 ± 9.5,respectively.Subjective scores were 4.58 ± 0.40,3.55 ± 0.57,and 2.75 ± 0.46,respectively.CNR,SNR and subjective scores had significant difference among groups (F =17.11,15.73 and 116.01,P ＜ 0.01).The optimal monochromatic group was superior to the 66 keV group and the 140 kVp mixed energy group.Conclusion The optimal monochromatic mode can improve CTA quality of small feeding arteries of abdomen malignant tumors with GSI technique using single source dual-energy CT.