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2012 Year 27 Volume 4 Issue
- Abstract：Objective To evaluate the image quality (IQ) and radiation dose of 128-slice dual-source computed tomography (DSCT) coronary angiography using prospectively electrocardiogram (ECG)-triggered sequential scan mode compared with ECG-gated spiral scan mode in a population with atrial fibrillation. Methods Thirty-two patients with suspected coronary artery disease and permanent atrial fibrillation referred for a second-generation 128-slice DSCT coronary angiography were included in the prospective study. Of them, 17 patients (sequential group) were randomly selected to use a prospectively ECG-triggered sequential scan, while the other 15 patients (spiral group) used a retrospectively ECG-gated spiral scan. The IQ was assessed by two readers independently, using a four-point grading scale from excel-lent (grade 1) to non-assessable (grade 4), based on the American Heart Association 15-segment model. IQ of each segment and effective dose of each patient were compared between the two groups. Results The mean heart rate (HR) of the sequential group was 96±27 beats per minute (bpm) with a variation range of 73±25 bpm, while the mean HR of the spiral group was 86±22 bpm with a variationrange of 65±24 bpm. Both of the mean HR (t=1.91, P=0.243) and HR variation range (t=0.950, P=0.350) had no significant difference between the two groups. In per-segment analysis, IQ of the sequential group vs. spiral group was rated as excellent (grade 1) in 190/244 (78%) vs. 177/217 (82%) by reader1 and 197/245 (80%) vs. 174/214 (81%) by reader2, as non-assessable (grade 4) in 4/244 (2%) vs. 2/217 (1%) by reader1 and 6/245 (2%) vs. 4/214 (2%) by reader2. Overall averaged IQ per-patient in the sequential and spiral group showed equally good (1.27±0.19 vs. 1.25±0.22, Z=-0.834, P=0.404). The effective radiation dose of the sequential group reduced significantly compared with the spiral group (4.88±1.77 mSv vs. 10.20±3.64 mSv; t=-5.372, P=0.000). Conclusion Compared with retrospectively ECG-gated spiral scan, prospectively ECG-triggered sequential DSCT coronary angiography provides similarly diagnostically valuable images in patients with atrial fibrillation and significantly reduces radiation dose.Keywords：atrial fibrillation;computed tomography;coronary angiography;prospectively electrocardio-gram-triggered sequential scan4|1237|0Updated：2024-04-10
- Abstract：Objective To retrospectively evaluate the effects of saline administration following contrast material injection, abdominal compression and two delay phase acquisition on image quality improvement of computed tomographic urography (CTU). Methods Medical records and informed consents of patients were obtained. In totally 122 patients (50 men, 72 women), two delay phase images with CTU were performed. Scans began simultaneously with a contrast bolus injection of 100 mL (300 mgI/mL) followed by a saline bolus injection of 100 mL at a rate of 5 mL/s. Two delay phase images were taken at 400 and 550 seconds for each patient. Examinations were taken by using abdominal compression or not. The distention and opacification of the urinary tract were evaluated by two interpreters together on transverse images and post-processing images. Effects of four techniques (saline administration and abdominal compression, saline administration only, compression only, and neither saline administration nor compression) and two delay phase acquisition on image quality improvement were analysed by using ANOVA and Chi-square test. Results Saline administration improved opacification (P<0.05) and increased overall image quality (P<0.01) of the intrarenal collecting system and proximal ureter. Abdominal compression (P<0.05) and delayed phase image acquisition of 550 seconds (P<0.01) all improved distention of the intrarenal collecting system and proximal ureter but did not improve opacification. No statistically significant effects on the distal ureter were found. However, there were more visualized distal ureteral segments with the longer imaging delay. Conclusion Saline administration, abdominal compression and longer imaging delays are all effective in improving image quality of 64-detector row CTU.Keywords：computed tomographic urography;image quality4|3008|0Updated：2024-04-10
- Abstract：Objective To quantitatively compare and determine the best pancreatic tumor contrast to noise ratio (CNR) in different dual-energy derived datasets. Methods In this retrospective, single center study, 16 patients (9 male, 7 female, average age 59.4±13.2 years) with pathologically diagnosed pancreatic cancer were enrolled. All patients received an abdominal scan using a dual source CT scanner 7 to 31 days before biopsy or surgery. After injection of iodine contrast agent, arterial and pancreatic parenchyma phase were scanned consequently, using a dual-energy scan mode (100 kVp/230 mAs and Sn 140 kVp/178 mAs) in the pancreatic parenchyma phase. A series of derived dual-energy datasets were evaluated including non-liner blending (non-linear blending width 0-500 HU; blending center -500 to 500 HU), mono-energetic (40-190 keV), 100 kVp and 140 kVp. On each datasets, mean CT values of the pancreatic parenchyma and tumor, as well as standard deviation CT values of subcutaneous fat and psoas muscle were measured. Regions of interest of cutaneous fat and major psoas muscle of 100 kVp and 140 kVp images were calculated. Best CNR of subcutaneous fat (CNRF) and CNR of the major psoas muscle (CNRM) of non-liner blending and mono-energetic datasets were calculated with the optimal mono-energetic keV setting and the optimal blending center/width setting for the best CNR. One Way ANOVA test was used for comparison of best CNR between different dual-energy derived datasets. Results The best CNRF (4.48±1.29) was obtained from the non-liner blending datasets at blending center -16.6±103.9 HU and blending width 12.3±10.6 HU. The best CNRF (3.28±0.97) was obtained from the mono-energetic datasets at 73.3±4.3 keV. CNRF in the 100 kVp and 140 kVp were 3.02±0.91 and 1.56±0.56 respectively. Using fat as the noise background, all of these images series showed significant differences (P<0.01) except best CNRF of mono-energetic image sets vs. CNRF of 100 kVp image (P=0.460). Similar results were found using muscle as the noise background (mono-energetic image vs. 100 kVp image: P=0.246; mono-energetic image vs. non-liner blending image: P=0.044; others: P<0.01). Conclusion Compared with mono-energetic datasets and low kVp datasets, non-linear blending image at automatically chosen blending width/window provides better tumor to the pancreas CNR, which might be beneficial for better detection of pancreatic tumors.Keywords：pancreatic adenocarcinoma;dual-energy;contrast to noise ratio;non-linear blending4|2257|0Updated：2024-04-10
- Abstract：Objective To prospectively investigate the diagnostic accuracy for coronary artery stenosis of prospectively electrocardiogram-triggered spiral acquisition mode (high pitch mode) dual-source computed tomography coronary angiography (CTCA) in patients with relatively higher heart rates (HR) compared with catheter coronary angiography (CCA). Methods Forty-seven consecutive patients with relatively higher HR (>65 and <100 bpm) (20 male, 27 female; age 55±10 years) who both underwent dual-source CTCA and CCA were prospectively included in this study. All patients were performed CTCA using high pitch mode setting at 20%-30% of the R-R interval for the image acquisition. All coronary segments were evaluated by two blinded and independent observers with regard to image quality on a three-point scale (1: excellent to 3: non-diagnostic) and for the presence of significant coronary stenoses (defined as diameter narrowing exceeding 50%). Considered CCA as the standard of reference, the sensitivity, specificity, positive predictive value and negative predictive value were calculated. Radiation dose values were calculated using the dose-length product. Results Image quality was rated as being score 1 in 92.4% of segments, score 2 in 6.1% of segmentsand score 3 in 1.5% of segments. The average image quality score per segment was 1.064±0.306. The HR variability of patients with image score 1, 2 and 3 were 2.29±1.06 bpm, 5.17±1.37 bpm, 8.88±1.53 bpm, respectively. The average HR variability of patients with different image scores were significantly different (F=170.402, P=0.001). The sensitivity, specificity, positive and negative predictive values were 92.6%, 97.0%, 87.6%, 98.3%, respectively, per segment and 90.0%, 95.2%, 85.3%, 96.9%, respectively, per vessel and 100%, 63.6%, 90.0%, 100%, respectively, per patient. The effective radiation dose was on average 0.86±0.16 mSv. Conclusion In patients with HR more than 65 bpm and below 100 bpm without cardiac arrhythmia, the prospectively electrocardiogram-gated high-pitch spiral acquisition mode with image acquired timing set at 20%-30% of the R-R interval provides a high diagnostic accuracy for the assessment of coronary stenoses combined with a 1.5% of non-diagnostic coronary segments and a radiation dose below 1 mSv.Keywords：high heart rate diagnostic accuracy4|1044|1Updated：2024-04-10
- Abstract：Objective To measure volume and other parameters of normal adrenal glands in Chinese adults with 64-slice multidetector CT, to evaluate the relationship of volume result with age, sex and body size, and to explore the correlations between adrenal volume and other measurements. Methods This study was based on 125 acquired contrast-enhanced upper abdominal CT scans performed with a 64-slice CT. The final study group consisted of 81 patients (49 males, 32 females). Portal venous phase images were studied for the measurements. Both the reconstruction interval and thickness were 1.5 mm. Each adrenal gland was outlined manually with computer-assistant technology to calculate its volume. The maximal sectional area, length, width and thickness of each adrenal gland were also measured. Results The mean age of total population was 47.9±13.0 (range: 20-76) years. The left, right, and total adrenal gland volumes were 4.23±0.74 (range: 2.85-5.83) cm3, 4.26±0.86 (2.59-6.56) cm3, and 8.50±1.40 (5.80-11.39) cm3, respectively. These volumes increased with weight (r=0.381, 0.389, and 0.437 respectively, all P<0.001), height (r=0.386, P<0.001; r=0.297, P=0.007; r=0.384, P<0.001) and body surface area (r=0.406, 0.392, and 0.452, all P<0.001). There was no significant difference in left, right or total adrenal volume with regard to sex after applying General Linear Model procedure to reduce the impact of weight (F=1.304, 0.064, and 0.597, all P>0.05), nor did volume change significantly with age (r=-0.033, -0.014, and -0.026, all P>0.05). Nearly all descriptors of bilateral adrenal glands correlated with ipsilateral volume except thickness (r=-0.027, P=0.814) and width (r=0.166, P=0.138) in the left side. Among these parameters, length had a stronger correlation with volume than others in the both left (r=0.412, P<0.001) and right (r=0.516, P<0.001) adrenal glands. Conclusion Our study has defined the volume distribution and other parameters of normal adrenal glands in Chinese adults, which provide a baseline for future studies.Keywords：adrenal gland;volumetry;volume determination;computed tomography6|2721|0Updated：2024-04-10
- Abstract：Objective To investigate the feasibility of acquiring the similar homogeneous enhancement using bolus-tracking techniques with shortened respiratory time in prospectively electrocardiogram-gated high-pitch spiral acquisition mode (Flash mode) coronary computed tomography angiography (CCTA) compared with test bolus technique. Methods One hundred and eighty-four consecutive patients with mean heart rate ≤65 beats per minute undergoing CCTA were prospectively included in this study. The patients were randomly divided into two groups. Patients in the group A (n=92) instructed to shorten respiratory time received CCTA using bolus-tracking technique with high-pitch spiral acquisition mode (Flash mode), while those in the group B (n=92) underwent CCTA with test bolus technique. The attenuation in the ascending aorta, image noise, contrast-to-noise ratio and radiation doses of the two groups were assessed. Results There were no significant differences in the mean attenuation values in the ascending aorta (483.18±59.07 HU vs. 498.7±83.51 HU, P=0.183), image noise (21.4±4.5 HU vs. 20.9±4.3 HU, P=0.414), contrast-to-noise ratio (12.1±4.2 vs. 13.8±5.1, P=0.31) between the groups A and B. There were no significant differences in the radiation dose of dynamic monitoring scans (0.056±0.026 mSv vs. 0.062±0.018 mSv, P=0.068) and radiation dose of angiography (0.94±0.07 mSv vs. 0.96±0.15 mSv, P=0.926) between the two groups, while 15 mL less contrast material volume was administered in the group A than the group B. Conclusion Bolus-tracking technique with shortened time of respiratory in Flash mode of dual-source CT yields the similar homogeneous enhancement with less contrast material in comparison to the test bolus technique.Keywords：dual-source computed tomography;coronary angiography;contrast;enhancement;test bolus technique;bolus-tracking technique4|1403|0Updated：2024-04-10
- Abstract：Objective To establish the normal measurements of diameter of extraocular muscles (EOMs) by multislice computed tomography (CT). Methods Orbits of 50 volunteers (25 male and 25 female) were scanned with a multislice CT scanner. For each subject, one axial image at the central level of the eyeball, one coronal image about 1 cm behind globe, and two oblique sagittal images respectively along the left and right optic nerve were used for measurements of the thickness and width of EOMs. The statistic significance of measurement value between male and female and between left and right eyes was evaluated. Results There were no significant differences in the thickness and width of superior muscle group, lateral rectus, medial rectus, lateral rectus, superior oblique, inferior oblique and the thickness of levator palpebrae superioris between the left and right eyes as well as between male and female groups (all P>0.05). The thickness of superior muscle group and inferior rectus had not significant difference (2.9±0.7 vs. 3.3±0.8 mm, P=0.162), while the thickness of medial rectus was significantly higher than that of lateral rectus (3.1±0.5 vs. 2.2±0.6 mm, P=0.000). Conclusions The CT measurement of extraocular musculature is simple and time-saving and can be applied in the clinical work. The normative data obtained may be useful in determining pathologic enlargement of the EOMs in both thyroid-associated orbitopathy patients and other various orbital conditions.Keywords：computed tomography;extraocular muscle;measurement4|2472|0Updated：2024-04-10
- Abstract：Objective To study the effects of obstructive sleep apneas on endothelial function and autonomic modulation. Methods From June 2009 to June 2011, male patients with obstructive sleep apnea hypopnea syndrome (OSAHS) were consecutively enrolled in this study. Patients with an apnea/hypopnea index (AHI) of greater than 15 and without previous treatment for OSAHS were included as Group OSAHS and obese subjects with an AHI of less than 5 were included as non-OSAHS controls (Group Control). Electrocardiography and beat-to-beat blood pressure were continuously recorded from the radial artery by applanation tonometry which was synchronized with polysomnography recording. Endothelial function was measured by arterial augmentation index (AAI). Spectral analysis of heart rate variability (HRV) and blood pressure variability (BPV) were computed for cardiac parasympathetic modulation (high frequency power, HF); sympathetic modulation (low frequency power, LF), sympathovagal balance (LF/HF power of R-R variability, LF/HF) and BPV sympathetic modulation (BPV LF) in normalized units [total power of the components/(total power-very LF power)×100]. Results Finally, 27 moderate-severe OSAHS patients and 22 non-OSAHS obese controls were recruited in the Group OSAHS and Group Control, respectively. In Group OSAHS, the age was 43.3±9.3 year-old, body mass index (BMI) was 36.8±8.7 kg/m2; in Group Control, the age was 42.9±8.6 year-old, BMI was 34.4±7.9 kg/m2; there were no significant differences in age and BMI between the Group OSAHS and Group Control (all P>0.05). The baseline AAI (12.5%±2.2% vs. 8.2%±2.1%) and BPV LF (68.3%±13.5% vs. 61.1%±11.7%) of the Group OSAHS were significantly higher than those of the Group Control (all P<0.05). And after overnight sleep, systolic BP (143.7±14.2 vs. 132.8±13.3 mm Hg), diastolic BP (87.7±7.7 vs. 78.6±5.5 mm Hg), HRV LF (69.7%±14.4% vs. 64.3%±12.1%), HRV LF/HF (3.7±2.0 vs. 2.3±1.3) and BPV LF (77.8%±15.6% vs. 68.3%±13.5%) of the Group OSAHS were significantly increased (all P<0.001), while HRV HF was significantly decreased (21.1%±9.3% vs. 27.5%±10.3%, P<0.05) from baseline.Keywords：obstructive sleep apnea;hypertension;endothelial function;autonomic;modulation;sympathetic activity4|1975|0Updated：2024-04-10
- Abstract：THE causes of Cushing′s syndrome are mainly divided into adrenocorticotropic hormone (ACTH) dependent and independent. ACTH dependent hypercortisolism represents excess ACTH se-creting by the pituitary or tumor outside the pituitary; and the latter one is also called as ectopic ACTH syndrome. Thorax is the most common location of causative lesions for ectopic ACTH syndrome, and the size of lesion is too small to be detected in some cases.1, 2 Cryptococcal pneumonia usually occurs in immunocompromised patients and excess cortisol production can theoretically produce a state of immunodeficiency. Development of cryptococcal pneumonia concomitant with Cushing syndrome (CS) was rare. Here, we report a case of pulmonary nodule in a patient with CS differentiated with ectopic ACTH-producing tumor. Cryptococcal pneumonia was diagnosed following lung resection.Keywords：Cushing syndrome;pulmonary cryptococcosis;ectopic adrenocorticotropic hormone-producing tumor6|2236|0Updated：2024-04-10
• Original Article •
- Abstract：Objective To study the effects of obstructive sleep apneas on endothelial function and autonomic modulation. Methods From June 2009 to June 2011, male patients with obstructive sleep apnea hypopnea syndrome (OSAHS) were consecutively enrolled in this study. Patients with an apnea/hypopnea index (AHI) of greater than 15 and without previous treatment for OSAHS were included as Group OSAHS and obese subjects with an AHI of less than 5 were included as non-OSAHS controls (Group Control). Electrocardiography and beat-to-beat blood pressure were continuously recorded from the radial artery by applanation tonometry which was synchronized with polysomnography recording. Endothelial function was measured by arterial augmentation index (AAI). Spectral analysis of heart rate variability (HRV) and blood pressure variability (BPV) were computed for cardiac parasympathetic modulation (high frequency power, HF); sympathetic modulation (low frequency power, LF), sympathovagal balance (LF/HF power of R-R variability, LF/HF) and BPV sympathetic modulation (BPV LF) in normalized units [total power of the components/(total power-very LF power)×100]. Results Finally, 27 moderate-severe OSAHS patients and 22 non-OSAHS obese controls were recruited in the Group OSAHS and Group Control, respectively. In Group OSAHS, the age was 43.3±9.3 year-old, body mass index (BMI) was 36.8±8.7 kg/m2; in Group Control, the age was 42.9±8.6 year-old, BMI was 34.4±7.9 kg/m2; there were no significant differences in age and BMI between the Group OSAHS and Group Control (all P>0.05). The baseline AAI (12.5%±2.2% vs. 8.2%±2.1%) and BPV LF (68.3%±13.5% vs. 61.1%±11.7%) of the Group OSAHS were significantly higher than those of the Group Control (all P<0.05). And after overnight sleep, systolic BP (143.7±14.2 vs. 132.8±13.3 mm Hg), diastolic BP (87.7±7.7 vs. 78.6±5.5 mm Hg), HRV LF (69.7%±14.4% vs. 64.3%±12.1%), HRV LF/HF (3.7±2.0 vs. 2.3±1.3) and BPV LF (77.8%±15.6% vs. 68.3%±13.5%) of the Group OSAHS were significantly increased (all P<0.001), while HRV HF was significantly decreased (21.1%±9.3% vs. 27.5%±10.3%, P<0.05) from baseline. △Supported by a grant from National Natural Science Foundation of China (81070072).Keywords：obstructive sleep apnea;hypertension;endothelial function;autonomic;modulation;sympathetic activity4|1990|0Updated：2024-04-10
- Abstract：Hepatitis B virus (HBV) infection has long been a critical public health challenge in China. National surveys revealed a prevalence of approximate 10% for chronic HBV infection in general population. HBV has been the leading cause of chronic hepatitis, cirrhosis, and liver cancers in Chinese population and a common pathogen of acute viral hepatitis. Meanwhile, the epidemic provided important opportunities to research the natural history, public health impact, and therapeutic and preventive interventions for HBV in China. In this review, we summarized the selected key epidemiological studies since 1970s regarding HBV infection and its associated liver diseases in China, and provided considerations for future research, prevention and treatment of HBV.Keywords：hepatitis B;epidemiology;cirrhosis;hepatocellular carcinoma4|3179|4Updated：2024-04-10
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