Quantitative assessment of lung cancer tumor vascular parameters by using high speed perfusion CT: influence of tumor region of interest / 中华放射学杂志

Objective To prospectively determine whether position and size of tumor region of interest (ROI) influence estimates of lung cancer vascular parameters at 256-slice CT perfusion study.Methods After institutional review board approval and informed consent,16 men and 11 women with lung cancer underwent 70-second CT perfusion study. Perfusion, blood volume, peak enhancement weredetermined for 60 or 120 mm2 circular ROIs placed at the tumor edge and center and around (outlining) visible tumor. ROI analysis was repeated twice by two observers in the same way to get the average values.The correlation between the measurements and microvascular density counts was determined in 19 patients with operation.Measurements were compared by using Pair-Samples t test,a difference with P≤0.05 was significant.Results Perfusion,blood volume,peak enhancement measurements were substantially higher at the edge than at the center for both 60 and 120 mm2 ROI. For 60 and 120 mm2 ROI,median of the three measurements were (M=15.40,9.50 ml · min- 1 · 100 ml - 1,M =35.60,25.40 ml · 100 g-1,and M=16.47,10.20 HU),respectively,at the edge versus(M =14.80,8.52 ml · min- 1 · 100 ml- 1,M =33.50,23.90 ml · 100 g- 1,and M =15.64,9.40 HU),respectively,at the center(t value was 10.95,9.80,7.06,2.93,7.74 and 10.09,respectively,all P ＜ 0.05 ). Measurements varied substantially depending on the ROI size,values for the ROI for outlined tumor were intermediate between those at the tumor edge and center.Perfusion(M=12.51 ml.min- 1 · 100 ml-1),blood volume(M=29.31 ml.100 g-1),peakenhancement (M =12.93 HU) for the ROI outlining tumor were intermediate between those at the tumor edge and center.There was a good correlation between perfusion,blood volume,peak enhancement for the ROI outlining tumor and microvascular density[ ( 19.43 ± 8.78 ) vessels/0.74 mm2 ],respectively ( r value 0.732,0.590 and 0.544,all P ＜ 0.05 ).Conclusions Position and size of tumor ROI substantially influence ultimate perfusion values.ROI for outlined entire tumor is more reliable for perfusion measurements and more appropriate clinically than use of arbitrarily determined smaller ROI.

Accuracy of coronary calcium measurements with low dose 64-slice multi-detector row CT / 中华放射医学与防护杂志

Objective To compare the low- and standard-dose protocols in the evaluation of coronary artery calcification (CAC) scores and in image quality,and to assess the accuracy of low-dose prospective ECG-gated helical CT in CAC measurements.Methods Forty-three patients with CAC were scanned twice using a tube current setting of 100 and 55 mA retrospectively.CAC scores (Agatston) of different branches of coronary artery were recorded.The mean and SD of the CT attenuation values in regions of interest in the aorta were measured,and the value (mean + 2 × SD) were obtained.Results Calcification plaques were found in 105 of the 172 vessels in the 43 subjects.The radiation dose of the 50 mAs group was (0.72 ± 0.04) mSy,significantly lower by 0.6 mSv than that of the 100 mAs group [(1.32 ± 0.08) mSv,P ＜ 0.05].The total calcification score of the 55 mAs group was significantly positively correlated with the routine dose group after performing the square root transformation (r =0.998).A signficant correlation existed in vessel-based calcification between these 2 groups (r= 0.997).Conclusions Low-dose prospective ECG-gated 64-slice CT yields high accuracy on CAC scoring while maintaining the image quality needed to measure CAC.

Analysis of the correlation between the degree of GBWT and hemodynamic changes of portal vein system / 生物医学工程学杂志

We retrospectively collected the ultrasound imaging data of 152 patients with cirrhosis, the gallbladder wall thickness (GBWT) and portal hemodynamics parameters (portal vein diameter, portal vein mean flow velocity, portal vein blood flow) were recorded,and SPSS 11.0 software was used to analyze the correlation between them. The results revealed that there was good correlation between portal vein diameter and the degree of gallbladder wall thickening (r 0.944, P < 0.05). Portal vein mean velocity and portal vein blood flow were both negatively correlated with gallbladder wall thickness (r = -0.939 or r = -0.950, respectively; both P < or = 0.005). These indicate that gallbladder wall thickening is closely related to hemodynamic parameters. It is feasible to predict the degree of portal hypertension through the observation of gallbladder wall thickening in patients with liver cirrhosis.

Imaging-anatomic study of diaphragmatic sternocostal triangle with double-phase 16-row MDCT / 生物医学工程学杂志

This study was aimed to determine the effects of respiratory phase, age, sex and body mass indexes (BMI) on the visibility and morphological characteristics of the diaphragmatic sternocostal triangle in normal adults shown by multi-detector computed tomography (MDCT). A total of 100 normal adults were consecutively recruited and scanned with 16-row MDCT at the end of deep expiration and inspiration. The visibility and morphological characteristics of diaphragmatic sternocostal triangle were observed. All cases were grouped according to the respiratory phase, age, sex and BMI, respectively. The visibility rates by MDCT among different types of sternocostal triangles at the inspiratory or the expiratory phases were calculated and compared, and the visibility rate was correlated with age, sex, and BMI, respectively. In addition, the CT features of diaphragmatic hernia (n=2) were recorded and analyzed. The visibility rate of trigonum sternocostal was 43% at the end of inspiration and 32% at the end of expiration. No difference was found in regard to age, gender and BMI (P > 0.05). Rupture of diaphragm and the features of adjacent abdominal organs into thoracic cavity were revealed clearly on multiplanar reformation (MPR) images of MDCT in 2 patients with diaphragmatic hernia. The visibility rates of diaphragmatic sternocostal triangle were associated with the respiratory movement. MPR on MDCT could be useful for revealing the anatomic structure of diaphragm and the radiological features of diaphragmatic hernia. Furthermore, double-phase scanning of MDCT provides feasible method for studying the physiologic information of diaphragm movement in normal status and abnormal status.

Assessment of global left and right ventricular function with 64 multi-detector row computed tomography in healthy adults / 生物医学工程学杂志

To evaluate the global left and right ventricular function and establish the CT reference data of global ventricular function parameters in normal people, 56 normal subjects (male, 28 cases; female, 28 case) were scanned with retrospective ECG gated 64-detector row CT. Ten time-phases in the cardiac cycle were reconstructed and short-axis images were acquired. On the cardiac analysis software, endo-cardium and epi-cardium of left and right ventricle were delineated and global function parameters were calculated. Left and right ventricular end-diastolic volume (LV/RVEDV), end-systolic volume (LV/RVESV), stroke volume (LV/RVSV), and wall mass (LV/RVWM) were significantly greater (P < 0.05) in men than in women, but cardiac output (LV/RVCO) and ejection fraction (LV/RVEF) exhibited no difference in women and men. In man group and woman group, LVWM was greater than RVWM (P < 0.01). LVESV, RVESV and body mass Index (BMI) were shown to have significant negative-correlation; the correlation coefficient = -0.54 and r = -0.53. LV/RVSV, LV/RVEF and BMI were noted to have significant positive-correlation; the correlation coefficients were 0.87/0.97 and 0.69/0.62, respectively. The normal global left and right ventricular functions differ significantly according to gender and body size.

Clinical application of 64-slice CT in evaluation of vessel before and after coronary artery bypass graft surgery / 生物医学工程学杂志

To determine the clinical value of 64-slice computed tomography angiography (CTA) in the evaluation of vessel before and after coronary artery bypass graft (CABG) surgery, we retrospectively collected the coronary artery imaging data of 46 patients undergoing 64 slice CT before CABG surgery in the period from July 2006 to May 2007, and we evaluated 14 patients with 39 coronary grafts in the same period to determine the diagnostic accuracy of CTA before and after CABG surgery. In 46 patients, 64-slice CT enabled the visualization of the entire coronary tree with diagnostic image quality. Sensitivity, specificity, and accuracy for the detection of stenosis > or = 50% were 92.11%, 95.64%, 94.97%, respectively. In 14 patients with 39 coronary grafts, 35 (35/39, 89.74%) bypass grafts were found to be of no stenosis; low degree of restenosis was found in 4 (4/39, 10.26%) bypass grafts, and no graft was found to have high degree of restenosis. So we concluded that, with the use of 64-slice CTA, we can accurately evaluate the degree of stenosis of vessel before and after CABG surgery.

Clinical application of 64-slice CT angiography in the evaluation of lumen before and after coronary artery stent implantation / 生物医学工程学杂志

This is a retrospective study aimed at the clinical application of 64-slice computed tomography angiography (CTA) in evaluation the lumen before and after coronary artery stent implantation. We collected the coronary artery imaging data of 46 patients undergoing 64-slice CT before coronary artery stent implantation from July 2006 through May 2007; we also collected the data of 21 patients with 34 coronary artery stents in the same period to determine the diagnostic accuracy of CTA before and after coronary artery stent implantation. The results showed that, in 46 patients, 64-slice CT enabled the visualization of the entire coronary tree with diagnostic image quality. Sensitivity, specificity, and accuracy for the detection of stenosis > or = 50% were 92.11%, 95.64% and 94.97%, respectively. In 21 patients with 34 stents implanted, 23 (67.65%) stents showed no stenosis, 8 (23.53%) stents showed low degree of restenosis, and 3 (8.83%) stents showed high degree of restenosis. In conclusion, we can accurately evaluate the degree of stenosis of lumen before and after coronary artery stent implantation with the application of 64-slice CTA.

The solitary pulmonary tuberculous cavity and malignant cavity: comparison on multi-detector row CT / 生物医学工程学杂志

The objective of this comparative study is to determine the MDCT features of solitary pulmonary tuberculous cavity and malignant cavity and to analyze the advantages there-of in differential diagnosis. The clinical data and MDCT findings of 51 cases of pulmonary tuberculous cavities and 39 cases of malignant cavities were reviewed retrospectively, which include the general aspects of patients, the manifestation of cavity and the changes of adjacent structures. The results revealed that the tuberculous cavity tends to locate in the upper lobe or the superior segment of lower lobe, and it is usually acompanied with cavity wall calcification, satellite lesions, peripheral inflammation, lymph node calcification, small diameter and thin wall thickness. The malignant cavities, showing no disposition to locate in a lobe or segment, are characterized by mural nodules, off-center cavity, lobulation, coarse speculation, lymph node enlargement, vascular clustering sign, big diameter and thick wall. In conclusion, with multiplanar reconstruction on multi-detector row CT, we could elaborate the cavities and the accompained lesions, thus contributing to a correct diagnosis in most cases.

MR urography of ectopic ureter orifice in children / 生物医学工程学杂志

To elucidate the MR urography (MRU) features of ectopic ureter orifice in children and to explicate its advantages, the clinical data and MRU findings of 4 cases with ectopic ureter orifice were analyzed retrospectively. Among the 4 cases of ectopic ureter orifice, 2 were associated with dysplasia of kidneys, 1 was associated with duplex kidney, and the remaining 1 was associated with cross ectopic and dyplasia kidney. When combining the MRI and MRU examination, we could diagnose the ectopic orifice of the draining ureters. So we concluded that definitive diagnosis could be achieved in most of the cases by integrating clinical information with MRU findings.