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Objective: To evaluate the correlation between image quality and thoracic diameters, anteroposterior diameter (AP) and right-left diameter (RL) for the optimization of reducing radiation dose in coronary artery imaging with Dual-source CT., Methods: 118 patients underwent CT coronary artery imaging (CTCA) were divided into two groups (A and B) according to body mass index (BMI). There were 58 patients in group A with BMI values > or = 25 kg/m2 and < 30 kg/m2; and 60 patients in group B with BMI values < 25 kg/m2. Scan parameters: collimation 64 X 0.6 mm, reconstruction slice thickness 0.75 mm, reconstructin interval 0.7 mm, FOV 150-180 mm, the pitch adjusted according to heart rate automatically. CT imagings were obtained with tube voltage 100 kV, tube current 330 mAs (group A) and 100 kV, tube current 220 mAs (group B). The contrast-noise ratio (CNR), signal to noise ratio (SNR), as well as blind correlation test score values were calculated to establish the relationship among BMI, AP, RL and CNR, SNR., Results: RL of five levels in groups of A, B were correlated to CNRa (P < 0.05). In group A and B (except iii, iv level of Group A), AP were associated with CNRa (P < 0.05). In addition to ii, iv level of group A, v level of group B, BMI were associated with CNRa (P < 0.05). The correlation coefficient of CNRa and RL of group A except ii level was greater than that of CNRa and AP. The correlation coefficient of CNRa, SNRa and RL of group B was greater than that of CNRa, SNRa and AP. Except iii level, the correlation coefficient of CNRa, SNRa and AP of group A was greater than that of CNRa, SNRa and BMI. Except ii level, the correlation coefficient of CNRa and AP of group B was greater than that of CNRa and BMI., Conclusion: Thoracic diameter of RL can be used as a guider to select the appropriate scan protocol in the coronary imaging acqusition with dual-source CT.

Objective: To develop a set of combined criteria of multiple features of chest CT for discriminating between benign and malignant lung lesions., Methods: Patients whose chest CT showed abnormalities were recruited from the West China Hospital in March and April 2010. The patients were examined with bronchoscopy and the results of CT and pathology were compared., Results: A total of 105 patients participated in this study and 85 had confirmed pathological results. The CT identified 27 cases of malignant lesions, 22 of which were confirmed by the pathology. The CT identified 58 cases of benign lesions, 55 of which were confirmed by the pathology. The set of combined criteria of multiple features of chest CT had an accuracy of 90.59%, a sensitivity of 88.00%, and a specificity of 91.67% in diagnosing benign and malignant lung lesions., Conclusion: The combined criteria of multiple imaging signs of CT have good clinical values for diagnosing malignant lung lesions.

Objective: To observe the superior attachment of renal fascia (RF) and the perirenal space (PS) in order to identify the spreading pathway of inflammatory and malignant tumors., Methods: Multidetector computed tomography (MDCT), with double phase enhancement scanning and three dimensional reconstruction of images were performed on 121 healthy adults. The RF attachments upward were observed and their connections with the PS were evaluated., Results: The left anterior renal fascia (ARF) fusing with peritoneum accounted for 27.3% (33/121) and the left ARF fusing with peritoneum of the spleen laterally and with the subdiaphragmatic fascia interiorly accounted for 19.8% (24/121) of the upper attachments of the RF above the upper renal pole (URP). Under the URP, the left ARF fusing with peritoneum accounted for 52.9% (64/121) of the upper attachments of the RF. The right ARF fusing with peritoneum did not display above the URP. The posterior renal fascia (PRF) of both side fused with subdiaphragmatic fascia under the URP. The ARF and PRF of the left and right kidney showed no upward integration. The right PS communicated with the subdiaphragmatic retroperitoneal space (SDRS) that is a bare area of the liver. The left PS communicating with the SDRS accounted for 80.2% (97/121) and the left PS communicating with the SDRS laterally but separating from the SDRS interiorly accounted for 19.8% (24/121) of the SDRS communication., Conclusion: MDCT and three-dimensional reconstruction can remarkably display RF and its superior attachment, as well as the connection between the PS and SDRS.

Objective: The purpose of this study was to investigate the effect of the degree of sternal depression on the cardiac rotation of pectus excavatum as depicted with helical CT., Materials and Methods: Sixty-three patients (53 boys, 10 girls; mean age, 9.7 +/- 7 years) with pectus excavatum who underwent helical chest CT and surgical correction were included in this study. Depth of sternal depression, CT depression index, cardiac rotation angle, and pulmonary vein angle were measured, and the correlation of these parameters was analyzed., Results: The mean sternal depression was 21 +/- 7 mm; CT depression index, 2.7 +/- 1.4; cardiac rotation angle, 55 degrees +/- 9 degrees ; and pulmonary vein angle, 52 degrees +/- 12 degrees . The sternal depression (18 mm) in patients with a CT depression index less than 2.4 was less than that in patients with a CT depression index of 2.4-2.9 (sternal depression, 21 mm) or greater than 2.9 (sternal depression, 28 mm) (p < 0.01). Similarly, the cardiac rotation angle (49 degrees +/- 5 degrees ) in patients with a CT depression index less than 2.4 was smaller than that in patients with a CT depression index of 2.4-2.9 (55 degrees +/- 6 degrees ) or greater than 2.9 (64 degrees +/- 12 degrees ) (p < 0.01). The pulmonary vein angle in patients with a CT depression index less than 2.4 (59 degrees +/- 11 degrees ) was larger than that in patients with a CT depression index of 2.4-2.9 (50 degrees +/- 12 degrees ) or a CT depression index greater than 2.9 (45 degrees +/- 8 degrees ) (p < 0.01). Cardiac rotation angle had a positive correlation with CT depression index (r = 0.75, p < 0.01)., Conclusion: The degree of sternal depression has a positive correlation with the degree of cardiac rotation in pectus excavatum. Helical CT is a valuable technique for evaluating the chest deformity and resultant cardiac rotation.

Objective: To determine the utility of 64-row multidetector computed tomography (MDCT) in assessing the changes of gastric fundic and oesophageal varices before and after transjugular intrahepatic portosystemic shunt (TIPS) with concurrent left gastric vein embolization., Methods: Twenty-eight consecutive patients with gastric fundic and oesophageal varices resulted from posthepatitic cirrhosis, clinically confirmed with endoscopy, were enrolled into our study. All the patients underwent thoracicoabdominal triphasic enhancement scans with 64-row MDCT 2 weeks before TIPS along with embolizing left gastric vein, and 6 months after the therapy. Before and after the therapy, the varices shown on multiplanar reconstruction (MPR) were compared by Fisher's exact test to evaluate the changes., Results: Gastric fundic and oesophageal varices were shown in 26 patients (92.9%) and 25 (89.3%) on MPR before the therapy, respectively. After the therapy, these varices diminished markedly, and were illustrated in six (21.4%) and 10 patients (35.7%), respectively (all P<0.05). As for the main inflowing vessel of the varices (left gastric vein), it was illustrated in 28 patients (100.0%) on preoperative CT-MPR. After the embolization, the left gastric vein had been completely occluded on postoperative CT-MPR., Conclusion: Significant eradication of gastric fundic and oesophageal varices on follow-up CT-MPR portography can be considered to assess the changes of gastric fundic and oesophageal varices before and after TIPS with concurrent left gastric vein embolization, and 64-row MDCT can be an effective modality to evaluate the changes.

Objective: To investigate the clinical application of first-pass perfusion MDCT in the assessment of tumor angiogenesis in carcinoma of esophagus and cardia., Methods: CT perfusion was performed with multi-detector row CT (MDCT) in 44 patients with carcinoma of esophagus and esophagogastric junction, who was diagnosed with pathological results and did not received any anti-tumor therapy. Twenty-one patients with peripheral lung cancer but normal esophagus were served as controls. Perfusion parameters were compared between normal and malignant esophagus, between adenocarcinoma and squamous cell carcinoma, as well as between tumors with metastases and those without metastases., Results: Carcinoma of esophagus and esophagogastric junction showed higher blood flow, peak enhancement index, blood volume, and shorter time to peak compared with normal esophagus (P < 0.05). There were no statistically significant differences in perfusion parameters between adenocarcinoma and squamous cell carcinoma (P > 0.05), whereas tumors with metastases showed higher blood flow and shorter time to peak compared with those without metastases (P < 0.05)., Conclusion: MDCT perfusion could assess tumor vascularity in carcinoma of esophagus and esophagogastric junction, and tumor vascularity or angiogenesis was not influenced by its histological type. However, high blood flow and short time-to-peak may be helpful to predict tumor metastases.

Objective: To use the time-density curves (TDCs) to quantitatively distinguish the true from false lumen of aortic dissection (AD)., Methods: 28 cases with AD underwent the dynamic scanning of 16-slice spiral computer tomography (SCT). We used the CT Dynamic Evaluation software to determine the circulation times of the true and false lumens of the AD and got the TDCs, and then analyzed the circulation times and CT values of the true and false lumens by using matched t-test for dependent samples., Results: The TDCs of the true and false lumens of the AD were achieved in all 28 patients. The peak CT values [(71.87 +/- 35.14) HU] of the true lumen were higher than those [(45.58 +/- 24.00) HU] of false lumen (P < 0.05); while the time to peak [(23.43 +/- 5.73) s] of the true lumen were earlier than that [(29.46 +/- 6.27) s] of false lumen (P < 0.05). The patterns of TDCs of the true lumen appeared to be rapid rise followed by rapid decline in 22 cases (78.6%) and rapid rise with gradual decline in 6 (21.4%), while the patterns of TDCs of the false lumen showed gradual rise followed by gradual decline in 18 cases (64.3%) and rapid rise with gradual decline in 10 (35.7%)., Conclusion: The TDCs of the true and false lumens showed: the peak CT values of the true lumen were higher than those of false lumen; while the time to peak of the true lumen were earlier than that of false lumen. So, the time-density curve, is used as an original and quantitative method to distinguish the true from false lumen in AD.

Objective: To evaluate the effects of low-dose helical CT with different scanning collimation on the visualization of segmental bronchi and to determine the optimal scanning collimation in CT screening for early central lung cancer., Methods: Forty healthy volunteers were randomly assigned to undergo the low-dose helical CT at 120 kVp, 50 mA, 0.75 s and pitch 1. One group (n = 20) underwent the sequential subsection scan of chest with the collimation of 10 mm for the apical and basilar zone, and of 8 mm and 5 mm for the hilar zone. The other (n = 20) went through CT scan with 10 mm collimation of the whole lung. The visualizations of lobar, segmental bronchi were compared at different collimations. ANOVA and multiple comparison were performed., Results: The visualization of segmental bronchi on low-dose scan at 10 mm collimation was 60%, being lower than that at 8 mm (88%) or 5 mm (91%) collimation (P < 0.01). The segmental bronchi of right upper lobe were easily identified at collimation of 10 mm (82%), 8 mm (96%) and 5 mm (98%), as well as those of left upper lobe at 10 mm (83%), 8 mm (95%) and 5 mm (97%), whereas those of lingular lobe were difficultly identified at 10 mm (30%), 8 mm (60%) and 5 mm (70%)., Conclusion: The lobar and segmental bronchi were visualized reliably by CT with 50 mA and 8 mm collimation, and therefore the sequential subsection scan of chest divided into three zones can be adapted to CT screening for early lung cancer.

Objective: To determine the correlation between helical CT findings and pulmonary function test (PFT) results from patients with idiopathic pulmonary fibrosis(IPF)., Methods: Helical CT scan was performed in 32 cases with clinically and/or pathologically proved idiopathic pulmonary fibrosis. Pulmonary function test for each patient was performed within 5 days before or after CT scan. The correlation between CT findings and pulmonary function test results was assessed., Results: Pulmonary function test revealed characteristic restrictive ventilatory defect with reduction of total lung capacity, residual volume, vital capacity, and diffusing capacity of the lung for carbon monoxide. The patients with different severities of pulmonary function impairment had different CT features. 4 of 5 cases with slight impairment of the pulmonary function had the ground-glass opacity, 11 cases with moderate impairment showed the thickened interlobular septa (11/11, 100%), thickened lobular interstitium (9/11, 82%), distorted lobular structures (11/11, 100%) and thickened bronchovascular bundles (10/11, 91%). 16 cases with marked impairment showed the honeycombing (16/16, 100%) and the traction bronchiectasis (9/16, 55%)., Conclusion: CT can provide significant information for the assessment of the pathologic severity of idiopathic pulmonary fibrosis. There is good correlation between CT findings and pulmonary function test results. CT combined with pulmonary function test can predict the progression, long term survival and response to therapy.