64层CT容积与常规高分辨率CT图像质量的比较

目的 比较容积高分辨率CT(VHRCT)与常规高分辨率CT(CHRCT)的图像质量,探讨VHRCT的可行性.方法 对Catphan 412模具行VHRCT及CHRCT扣描,测量和记录图像的空间分辨率、噪声及放射剂量并进行比较;对32例患者行VHRCT及CHRCT检查,对图像质量进行评分并比较.模具部分采用配对t检验比较噪声的差异;临床部分采用Wilcoxon配对符号秩和检验比较图像质量的差异.结果 模具研究中,VHRCT横断面图像的空间分辨率与CHRCT相同,均为11 LP/cm,其z轴分辨率为12 LP/cm.剂量相近时,VHRCT的噪声为(69.18±2.77)HU,大于CHRCT的噪声(54.62±2.12)HU,(t=-15.929,P＜0.01);噪声相近时,VHRCT的剂量较CHRCT增加19.09 mGy.临床研究中,VHRCT与CHRCT横断面图像的质量评分分别为3.22与3.24,差异无统计学意义(Z=-0.319,P＞0.05),VHRCT与CHRCT冠状面蕈建图像的质量评分分别为3.05与1.88,差异有统计学意义(Z=-5.088,P＜0.01).结论 对于64层CT,VHRCT的横断面图像质量接近CHRCT,多平面重组图像具有高分辨率可广泛应用,其扫描剂量尚有待优化.     

Capability of abdominal 320-detector row CT for small vasculature assessment compared with that of 64-detector row CT

Objective

To compare the capability of 320-detector row CT (area-detector CT: ADCT) with step-and-shoot scan protocol for small abdominal vasculature assessment with that of 64-detector row CT with helical scan protocol.

Materials and methods

Total of 60 patients underwent contrast-enhanced abdominal CT for preoperative assessment. Of all, 30 suspected to have lung cancer underwent ADCT using step-and-shoot scan protocol. The other 30 suspected to have renal cell carcinoma underwent 64-MDCT using helical scan protocol. Two experienced radiologists independently assessed inferior epigastric, hepatic subsegmental (in the segment 8), mesenteric marginal (Griffith point) and inferior phrenic arteries by using 5-point visual scoring systems. Kappa analysis was used for evaluation of interobserver agreement. To compare the visualization capability of the two systems, the Mann-Whitney U-test was used to compare the scores for each of the arteries.

Results

Overall interobserver agreements for both systems were almost perfect (κ > 0.80). Visualization scores for inferior epigastric and mesenteric arteries were significantly higher for ADCT than for 64-detector row CT (p < 0.05). No significant difference was found for hepatic subsegmental and inferior phrenic arteries.

Conclusion

Small abdominal vasculature assessment by ADCT with step-and-shoot scan protocol is potentially equal to or better than that by 64-detector row CT with helical scan protocol.     

320层容积CT和64层螺旋CT在胰腺解剖结构显示、影像质量和辐射剂量方面的对照研究

目的前瞻性对比研究320层容积CT和64层螺旋CT对胰腺解剖结构的显示、影像质量以及辐射剂量。材料与方法本研究经机构伦理委员会批准,并签署知情同意。共     

Identification of the anterior ethmoid arteries on thin-section axial images and coronal reformatted orbit images by means of multidetector row CT

AIM: The aim of this study was to identify anterior ethmoid arteries on thin-section axial images and coronal reformatted images of the orbits using multidetector row computed tomography (CT). MATERIALS AND METHODS: One hundred and thirty-two patients underwent paranasal CT using a 16-row detector CT (n=59) or a 6-row detector CT machine (n=73) at 1 or 1.25 mm section width, respectively. Coronal images were reformatted at section widths of 3 and 1 mm. The anterior ethmoid arteries were identified for each patient. Differences were assessed using the chi-square test. RESULTS: All CT images were of approximately average diagnostic quality. Anterior ethmoid arteries were identified in 97.5 and 96.6% at section thicknesses of 1 and 1.25 mm on the axial images, respectively. There was no statistically significant difference in the detection rate (p=0.89). On the coronal images, anterior ethmoid arteries were presented tangentially in 75.4 and 90.2% at section widths of 3 and 1 mm, respectively. The visibility of the anterior ethmoid arteries was rated significantly better on coronal images at a section width of 1 mm than on those at section widths of 3 mm (p<0.001). CONCLUSION: Thin-section axial images and coronal reformatted images using multi-detector row CT mostly depict anterior ethmoid arteries, and are useful to identify anterior ethmoid arteries for preoperative evaluation of paranasal sinuses.     

调整螺距对64层螺旋CT冠状动脉成像图像质量的影响

Objective To investigate the impact of imaging quality of pitch on coronary CT angiography (CTA) with 64-detector row CT. Methods 566 patients were divided into four groups according to heart rate (≤ 50,51-70,71 ～ 80 and ≥ 80 bpm). Three dimensional reconstructions were used such as volume rendering (VR) ,maximum intensity projection(MIP) and curved planar reformation(CPR). Each group was divided into control group and cxperimential group randomly, using normal pitch and revised pitch respectively, and the imaging quality and influencing factons were analyzed among the four groups. Results There was significant difference in imaging quality among the four groups (P < 0.05). Each group had difference in imaging quality with normal pitch and revised pitch. Conclusions The revised pitch helps to improve the imaging quality and meet the demand of diagnosis.     

调整螺距对64层螺旋CT冠状动脉成像图像质量的影响

Objective To investigate the impact of imaging quality of pitch on coronary CT angiography (CTA) with 64-detector row CT. Methods 566 patients were divided into four groups according to heart rate (≤ 50,51-70,71 ～ 80 and ≥ 80 bpm). Three dimensional reconstructions were used such as volume rendering (VR) ,maximum intensity projection(MIP) and curved planar reformation(CPR). Each group was divided into control group and cxperimential group randomly, using normal pitch and revised pitch respectively, and the imaging quality and influencing factons were analyzed among the four groups. Results There was significant difference in imaging quality among the four groups (P < 0.05). Each group had difference in imaging quality with normal pitch and revised pitch. Conclusions The revised pitch helps to improve the imaging quality and meet the demand of diagnosis.     

调整螺距对64层螺旋CT冠状动脉成像图像质量的影响

Objective To investigate the impact of imaging quality of pitch on coronary CT angiography (CTA) with 64-detector row CT. Methods 566 patients were divided into four groups according to heart rate (≤ 50,51-70,71 ～ 80 and ≥ 80 bpm). Three dimensional reconstructions were used such as volume rendering (VR) ,maximum intensity projection(MIP) and curved planar reformation(CPR). Each group was divided into control group and cxperimential group randomly, using normal pitch and revised pitch respectively, and the imaging quality and influencing factons were analyzed among the four groups. Results There was significant difference in imaging quality among the four groups (P < 0.05). Each group had difference in imaging quality with normal pitch and revised pitch. Conclusions The revised pitch helps to improve the imaging quality and meet the demand of diagnosis.     

调整螺距对64层螺旋CT冠状动脉成像图像质量的影响

Objective To investigate the impact of imaging quality of pitch on coronary CT angiography (CTA) with 64-detector row CT. Methods 566 patients were divided into four groups according to heart rate (≤ 50,51-70,71 ～ 80 and ≥ 80 bpm). Three dimensional reconstructions were used such as volume rendering (VR) ,maximum intensity projection(MIP) and curved planar reformation(CPR). Each group was divided into control group and cxperimential group randomly, using normal pitch and revised pitch respectively, and the imaging quality and influencing factons were analyzed among the four groups. Results There was significant difference in imaging quality among the four groups (P < 0.05). Each group had difference in imaging quality with normal pitch and revised pitch. Conclusions The revised pitch helps to improve the imaging quality and meet the demand of diagnosis.     

调整螺距对64层螺旋CT冠状动脉成像图像质量的影响

Objective To investigate the impact of imaging quality of pitch on coronary CT angiography (CTA) with 64-detector row CT. Methods 566 patients were divided into four groups according to heart rate (≤ 50,51-70,71 ～ 80 and ≥ 80 bpm). Three dimensional reconstructions were used such as volume rendering (VR) ,maximum intensity projection(MIP) and curved planar reformation(CPR). Each group was divided into control group and cxperimential group randomly, using normal pitch and revised pitch respectively, and the imaging quality and influencing factons were analyzed among the four groups. Results There was significant difference in imaging quality among the four groups (P < 0.05). Each group had difference in imaging quality with normal pitch and revised pitch. Conclusions The revised pitch helps to improve the imaging quality and meet the demand of diagnosis.     

调整螺距对64层螺旋CT冠状动脉成像图像质量的影响

目的 探讨64层螺旋CT调整螺距对冠状动脉成像图像质量的影响。方法 对566例患者进行64层螺旋CT心脏冠状动脉成像,以容积再现(VR)、最大密度投影(MIP) 和曲面重组(CPR)等技术行冠状动脉三维成像,以心率≤50、51~70、71~80 及≥80次/min分为4组,每组随机分为常规组及修改组,采用常规螺距及修订螺距扫描,评价图像质量,分析其影响。结果 4组组间冠状动脉成像优良率差异有统计学意义(P＜0.05),各组间不同螺距图像质量差异有统计学意义(P<0.01)。对心率较快(71~80 次/min)或(≥80 次/min)但心率整齐,更改螺距能有效提高图像质量,达到诊断目的。结论 64层螺旋CT冠状动脉成像通过调整螺距能有效提高心率较快时图像质量,达到优化诊断的效果。     

调整螺距对64层螺旋CT冠状动脉成像图像质量的影响

Objective To investigate the impact of imaging quality of pitch on coronary CT angiography (CTA) with 64-detector row CT. Methods 566 patients were divided into four groups according to heart rate (≤ 50,51-70,71 ～ 80 and ≥ 80 bpm). Three dimensional reconstructions were used such as volume rendering (VR) ,maximum intensity projection(MIP) and curved planar reformation(CPR). Each group was divided into control group and cxperimential group randomly, using normal pitch and revised pitch respectively, and the imaging quality and influencing factons were analyzed among the four groups. Results There was significant difference in imaging quality among the four groups (P < 0.05). Each group had difference in imaging quality with normal pitch and revised pitch. Conclusions The revised pitch helps to improve the imaging quality and meet the demand of diagnosis.     

调整螺距对64层螺旋CT冠状动脉成像图像质量的影响

Objective To investigate the impact of imaging quality of pitch on coronary CT angiography (CTA) with 64-detector row CT. Methods 566 patients were divided into four groups according to heart rate (≤ 50,51-70,71 ～ 80 and ≥ 80 bpm). Three dimensional reconstructions were used such as volume rendering (VR) ,maximum intensity projection(MIP) and curved planar reformation(CPR). Each group was divided into control group and cxperimential group randomly, using normal pitch and revised pitch respectively, and the imaging quality and influencing factons were analyzed among the four groups. Results There was significant difference in imaging quality among the four groups (P < 0.05). Each group had difference in imaging quality with normal pitch and revised pitch. Conclusions The revised pitch helps to improve the imaging quality and meet the demand of diagnosis.     

调整螺距对64层螺旋CT冠状动脉成像图像质量的影响

Objective To investigate the impact of imaging quality of pitch on coronary CT angiography (CTA) with 64-detector row CT. Methods 566 patients were divided into four groups according to heart rate (≤ 50,51-70,71 ～ 80 and ≥ 80 bpm). Three dimensional reconstructions were used such as volume rendering (VR) ,maximum intensity projection(MIP) and curved planar reformation(CPR). Each group was divided into control group and cxperimential group randomly, using normal pitch and revised pitch respectively, and the imaging quality and influencing factons were analyzed among the four groups. Results There was significant difference in imaging quality among the four groups (P < 0.05). Each group had difference in imaging quality with normal pitch and revised pitch. Conclusions The revised pitch helps to improve the imaging quality and meet the demand of diagnosis.     

调整螺距对64层螺旋CT冠状动脉成像图像质量的影响

Objective To investigate the impact of imaging quality of pitch on coronary CT angiography (CTA) with 64-detector row CT. Methods 566 patients were divided into four groups according to heart rate (≤ 50,51-70,71 ～ 80 and ≥ 80 bpm). Three dimensional reconstructions were used such as volume rendering (VR) ,maximum intensity projection(MIP) and curved planar reformation(CPR). Each group was divided into control group and cxperimential group randomly, using normal pitch and revised pitch respectively, and the imaging quality and influencing factons were analyzed among the four groups. Results There was significant difference in imaging quality among the four groups (P < 0.05). Each group had difference in imaging quality with normal pitch and revised pitch. Conclusions The revised pitch helps to improve the imaging quality and meet the demand of diagnosis.     

调整螺距对64层螺旋CT冠状动脉成像图像质量的影响

Objective To investigate the impact of imaging quality of pitch on coronary CT angiography (CTA) with 64-detector row CT. Methods 566 patients were divided into four groups according to heart rate (≤ 50,51-70,71 ～ 80 and ≥ 80 bpm). Three dimensional reconstructions were used such as volume rendering (VR) ,maximum intensity projection(MIP) and curved planar reformation(CPR). Each group was divided into control group and cxperimential group randomly, using normal pitch and revised pitch respectively, and the imaging quality and influencing factons were analyzed among the four groups. Results There was significant difference in imaging quality among the four groups (P < 0.05). Each group had difference in imaging quality with normal pitch and revised pitch. Conclusions The revised pitch helps to improve the imaging quality and meet the demand of diagnosis.     

Whole tumour perfusion of peripheral lung carcinoma: evaluation with first-pass CT perfusion imaging at 64-detector row CT

AIM: To prospectively assess the feasibility of a whole-tumour perfusion technique using 64-detector row computed tomography (CT) and to analyse the variation of CT perfusion parameters in different histological types, sizes, and metastases in patients with peripheral lung carcinoma. METHODS AND MATERIALS: Ninety-seven pathologically proved peripheral lung carcinomas (less than 5 cm in largest diameter) underwent dynamic contrast-enhanced CT using a 64-detector row CT machine. Small amounts of iodinated contrast medium with a sharp bolus profile (50 ml, 6-7 ml/s), and 12 repeated fast acquisitions encompassing the entire tumour lesion were adopted to quantify perfusion of the whole-tumour during first-pass of contrast medium. Four kinetic parameters, including perfusion, peak enhancement intensity (PEI), time to peak (TTP), and blood volume (BV), were measured and statistically compared among different histological types, sizes, and metastases. RESULTS: Mean values for perfusion, PEI, TTP, and BV of the 97 lung carcinomas were 57.5+/-45.4 ml/min/ml (range 5.9-243 ml/min/ml), 53.4+/-40.6 HU (range 10.3-234.4 HU), 34+/-11s (range 11-60s), and 30.1+/-21.7 ml/100g (range 3.9-113.4 ml/100g), respectively. No statistical differences were found between the histological types regarding the perfusion parameters (p>0.05). Perfusion, PEI, and BV of stage T2 tumours were significantly lower than those of stage T1 tumours (all p < 0.05), whereas no statistically significant differences was found between other stages of tumours (all p>0.05). Perfusion of the tumours with distant metastasis was significantly higher than that of the tumours without distant metastasis (p<0.05), but there was no statistically significant difference between nodal metastasis positive and negative groups (p>0.05). CONCLUSION: The present study of first-pass perfusion imaging using 64-detector row CT could provide a feasible method for assessment of whole-tumour perfusion. CT perfusion parameters of peripheral lung carcinoma may be associated with tumour size and distant metastasis.     

Evaluation of thoracic abnormalities on 64-row multi-detector row CT: comparison between axial images versus coronal reformations

PURPOSE: To evaluate the capability of coronal reformations of chest on 64-row MDCT in demonstrating thoracic abnormalities in comparison with axial images. MATERIALS AND METHODS: Thirty-eight consecutive patients who underwent pulmonary CTA on 64-row MDCT were retrospectively studied with institutional review board (IRB) approval. Contiguous 2 mm axial and coronal images were reviewed independently with a 1-week interval, by consensus reading of two board-certified radiologists. Overall image quality was graded using a five-point scale. Abnormalities in mediastinum, hilum, pulmonary vessels, aorta, heart, esophagus, pleura, chest wall, and lung parenchyma were scored: 1 = definitely absent, 2 = probably absent, 3 = equivocal, 4 = probably present, 5 = definitely present. Scores on axial and coronal images were compared using weighted kappa analysis. RESULTS: Overall image quality was not different with statistical relevance between axial and coronal images (mean/median scores; 3.7/4; 3.6/4, respectively, P = 0.286, Wilcoxon signed-rank test). Significant agreement was observed between axial and coronal scores (mean weighted kappa, 0.661; range, 0.362-1). Agreement was almost perfect for pneumothorax, lung and pleural mass, effusion and consolidation (weighted kappa=0.833-1); substantial for pulmonary embolism, trachea, mediastinal lymphadenopathy and non-skeletal chest wall lesion, heart, esophagus, and emphysema (weighted kappa, 0.618-0.799); moderate for atelectasis, mediastinum, hilar nodes, aorta, other lung lesions, skeletal chest wall lesions, linear scarring, nodules > 1 cm, pulmonary artery abnormalities and pleural thickening (weighted kappa, 0.405-0.592); and fair for nodules < 1 cm (weighted kappa = 0.362). CONCLUSION: Coronal reformations on 64-row MDCT had substantial agreement with axial images for evaluation of the majority of thoracic abnormalities.