Objectine To study the performance between CR and DR equipments. Methods To compare chest x-ray between the CR and DR equipment. Results The pathological detection with DR equipment is 20% higher than that with CR. Conclusion The quantity of information of DR is higher than CR.

Objective To analyze the clinical characteristics of suspected acute aortic dissection with ST-segment elevation detected by inferior leads in order to avoid the misdiagnosis of acute aortic dissection facilitating an appropriate treatment strategy carried out in time.Methods A total of 14 patients with suspected acute aortic dissection with ST-segment elevation detected by inferior leads were enrolled.Their clinical presentation,ECG features,imaging findings,laboratory testing,coronary angiography results, treatment and outcome were retrospectively analyzed.Results Clinical characteristics of suspected acute aortic dissection with ST-segment elevation detected by inferior leads suggested that hypertension as a single risk factor accounted for 79%.The patients with normal blood pressure or high blood pressure in emergency visits accounted for 86%.The amplitude of ST elevation in lead Ⅲ was greater than that in lead Ⅱ,and lead Ⅲ accompanied with ST elevation in lead V1 or V4R accounted for 86%.Significantly elevated D-dimer >2 000 ng/mL was found in those patients.Coronary angiography showed that the opening of coronary artery not seen,normal coronary arteries or a simple right coronary artery proximal lesion.Transesophageal echocardiography and computed tomography angiography were used to identify the diagnosis with 100%accuracy.The mortality rate of this group was 50%.Conclusions Patients with acute aortic dissection evidenced by ST-segment elevation detected by inferior leads are in critical setting of high mortality. Emergency surgical treatment can significantly improve the survival rate of patients.

OBJECTIVE: To investigate the value of spectral CT imaging in the diagnosis and classification of liver cirrhosis during the arterial phase (AP) and portal venous phase (PVP). MATERIALS AND METHODS: Thirty-eight patients with liver cirrhosis (Child-Pugh class A/B/C: n = 10/14/14), and 43 patients with healthy livers, participated in this study. The researchers used abdominal spectral CT imaging during AP and PVP. Iodine concentration, derived from the iodine-based material-decomposition image and the iodine concentration ratio (ICratio) between AP and PVP, were obtained. Statistical analyses {two-sample t test, One-factor analysis of variance, and area under the receiver operating characteristic curve (A [z])} were performed. RESULTS: The mean normalized iodine concentration (NIC) (0.5 +/- 0.12) during PVP in the control group was significantly higher than that in the study group (0.4 +/- 0.10 on average, 0.4 +/- 0.08 for Class A, 0.4 +/- 0.15 for Class B, and 0.4 +/- 0.06 for Class C) (All p < 0.05). Within the cirrhotic liver group, the mean NIC for Class C during the AP (0.1 +/- 0.05) was significantly higher than NICs for Classes A (0.1 +/- 0.06) and B (0.1 +/- 0.03) (Both p < 0.05). The ICratio in the study group (0.4 +/- 0.15), especially for Class C (0.5 +/- 0.14), was higher than that in the control group (0.3 +/- 0.15) (p < 0.05).The combination of NIC and ICratio showed high sensitivity and specificity for differentiating healthy liver from cirrhotic liver, especially in Class C cirrhotic liver. CONCLUSION: Spectral CT Provides a quantitative method with which to analyze the cirrhotic liver, and shows the potential value in the classification of liver cirrhosis.
Analysis of Variance ; Case-Control Studies ; Contrast Media/diagnostic use ; Female ; Humans ; Liver/pathology ; Liver Cirrhosis/pathology/*radiography ; Male ; Middle Aged ; Prospective Studies ; ROC Curve ; Sensitivity and Specificity ; Tomography, X-Ray Computed/*methods ; Triiodobenzoic Acids/diagnostic use

OBJECTIVE: To assess the lesion conspicuity and image quality in CT evaluation of small (< or = 3 cm) hepatocellular carcinomas (HCCs) using automatic tube voltage selection (ATVS) and automatic tube current modulation (ATCM) with or without iterative reconstruction. MATERIALS AND METHODS: One hundred and five patients with 123 HCC lesions were included. Fifty-seven patients were scanned using both ATVS and ATCM and images were reconstructed using either filtered back-projection (FBP) (group A1) or sinogram-affirmed iterative reconstruction (SAFIRE) (group A2). Forty-eight patients were imaged using only ATCM, with a fixed tube potential of 120 kVp and FBP reconstruction (group B). Quantitative parameters (image noise in Hounsfield unit and contrast-to-noise ratio of the aorta, the liver, and the hepatic tumors) and qualitative visual parameters (image noise, overall image quality, and lesion conspicuity as graded on a 5-point scale) were compared among the groups. RESULTS: Group A2 scanned with the automatically chosen 80 kVp and 100 kVp tube voltages ranked the best in lesion conspicuity and subjective and objective image quality (p values ranging from < 0.001 to 0.004) among the three groups, except for overall image quality between group A2 and group B (p = 0.022). Group A1 showed higher image noise (p = 0.005) but similar lesion conspicuity and overall image quality as compared with group B. The radiation dose in group A was 19% lower than that in group B (p = 0.022). CONCLUSION: CT scanning with combined use of ATVS and ATCM and image reconstruction with SAFIRE algorithm provides higher lesion conspicuity and better image quality for evaluating small hepatic HCCs with radiation dose reduction.
Adult ; Aged ; Aged, 80 and over ; Algorithms ; Carcinoma, Hepatocellular/*radiography ; Contrast Media ; Female ; Fluoroscopy ; Humans ; Image Enhancement/*methods ; Liver Neoplasms/*radiography ; Male ; Middle Aged ; Prospective Studies ; Radiation Dosage ; Radiographic Image Interpretation, Computer-Assisted/*methods ; Tomography, X-Ray Computed/*methods ; Young Adult