Preoperative assessment of mitral valve abnormalities in left atrial myxoma patients using cardiac CT.

BACKGROUND: To retrospectively evaluate mitral valve abnormality in left atrial myxoma patients by using cardiac computed tomography (CT). MATERIAL AND METHODS: Cardiac CT was performed in 56 patients with left atrial myxoma and 50 controls. Tumor and mitral valve characteristics were analyzed. The mitral valve parameters differences were compared between patients with myxoma and controls, myxoma with or without mitral valve obstruction, different obstruction degrees, respectively. Receiver operating characteristic analysis was performed to determine the cut-off values of abnormal mitral valve parameters for myxoma patients. Multiple linear regression, logistic regression models and cox regression analysis were used to determine factors associated with mitral valve abnormalities, mitral obstruction, mitral regurgitation and postoperative recovery, respectively. RESULTS: Myxoma induced the dilation of mitral valve, with different results among different degrees of obstruction (p<0.001). Mitral valve parameters had relationship with myxoma parameters. The cut-off values for discriminating mitral valve abnormalities in myxoma patients were found. Some significant predictors for mitral obstruction were tumor pedicle-tumor volume and patient age (HR, 0.886-30.811; p = 0.011-0.043). Moreover, the predictor for mitral regurgitation was mitral annulus diameter in diastolic phase (HR, 20.862; 95%CI,1.331-327.100; p = 0.031). Some predictors associated with postoperative recovery of mitral regurgitation were age, mitral annulus area, mitral annulus diameter and mitral valve diameter cutoff value for diastolic phase (HR, 0.001-119.160; p = 0.012-0.028). CONCLUSION: Cardiac CT is capable of quantitatively assessing myxoma characteristic and mitral valve abnormality induced by myxoma, thus providing guidance of operative management and postoperative evaluation.

ROI for outlining an entire tumor is a reliable approach for quantification of lung cancer tumor vascular parameters using CT perfusion.

OBJECTIVE: To investigate the effect of position and size of tumor region of interest (ROI) on the estimation of lung cancer vascular parameters using 256-slice computed tomography (CT) perfusion. METHODS: After institutional review board approval and written informed consent, 16 men and 11 women with lung cancer were enrolled in this CT perfusion study. Perfusion, blood volume, and peak enhancement were determined for 60 or 120 mm(2) circular ROIs placed at the edge, center, and around (outlining) the visible tumor. Average values were obtained by performing ROI analysis twice by the same observers without any procedural changes. RESULTS: Perfusion, blood volume, and peak enhancement measurements were substantially higher at the edge than at the center for both 60 and 120 mm(2) ROIs (all P<0.05). Measurements varied substantially depending on the ROI size. Perfusion, blood volume, and peak enhancement for the ROIs outlining tumor were intermediate between those at the tumor edge and center. There were significant correlations between median values and interquartile ranges as follows; perfusion (12.51 [7.91-28.10] mL⋅min(-1)⋅100 mL(-1)), blood volume (29.31 [21.82-37.65] mL⋅100 g(-1)), peak enhancement (12.93 [2.42-22.50]) for the ROIs outlining the tumor, and microvascular density ([19.43±8.78] vessels/0.74 mm(2)), respectively (r values were 0.732, 0.590, and 0.544 respectively, all P<0.05). CONCLUSION: Spatial and size selection of ROI significantly affects CT perfusion analysis. ROI outlining of entire tumor provides efficient and reliable measurements for clinical assessment of lung cancer using CT perfusion.

The reduction of volume and fiber bundle connections in the hippocampus of EGR3 transgenic schizophrenia rats.

BACKGROUND AND OBJECTIVE: There is a growing consensus that schizophrenia is ultimately caused by abnormal communication between spatially disparate brain structures. White matter fasciculi represent the primary infrastructure for long distance communication in the brain. In this study, we aimed to investigate the white matter connection in schizophrenia susceptible brain regions of early growth response factor 3 (EGR3) expressing rats. METHODS: A rat model of schizophrenia was created by the transfection of the EGR3 gene into rat hippocampus. All animals were placed in a fixation system using a commercial rat-dedicated coil. Schizophrenia susceptible brain regions were scanned using in vivo diffusion tensor magnetic resonance imaging. The volume, quantity, average length of fiber bundles, fractional anisotropy, apparent diffusion coefficient, the relative heterosexual fraction, and volume ratio were collected in the whole brain and schizophrenia related brain areas (the hippocampus, thalamus, and prefrontal lobe). MedINRIA software was used for data processing of diffusion tensor and fiber bundles tracking. The fibronectin in relevant brain regions was also analyzed. RESULTS: There was a significant decrease in the volume of the fiber beam through the left hippocampus dentate in the schizophrenia model group in comparison to the control group and the risperidone treatment group (P<0.05). A significant reduction in the volume and number of the fiber bundles was also observed in left prefrontal-left hippocampus, left hippocampus-left thalamus, left prefrontal-left hippocampus-left thalamus areas in the model group (all P<0.05). CONCLUSION: The volume of hippocampus and the number of fiber bundles were reduced in EGR3 transgenic schizophrenia rats, and are the most sensitive indicators in schizophrenia. The diffusion tensor imaging technique plays an important role in the evaluation of patients with schizophrenia.

Functional magnetic resonance imaging reveals abnormal brain connectivity in EGR3 gene transfected rat model of schizophrenia.

Schizophrenia is characterized by the disorder of "social brain". However, the alternation of connectivity density in brain areas of schizophrenia patients remains largely unknown. In this study, we successfully created a rat model of schizophrenia by the transfection of EGR3 gene into rat brain. We then investigated the connectivity density of schizophrenia susceptible regions in rat brain using functional magnetic resonance imaging (fMRI) in combination with multivariate Granger causality (GC) model. We found that the average signal strength in prefrontal lobe and hippocampus of schizophrenia model group was significantly higher than the control group. Bidirectional Granger causality connection was observed between hippocampus and thalamic in schizophrenia model group. Both connectivity density and Granger causality connection were changed in prefrontal lobe, hippocampus and thalamus after risperidone treatment. Our results indicated that fMRI in combination with GC connection analysis may be used as an important method in diagnosis of schizophrenia and evaluation the effect of antipsychotic treatment. These findings support the connectivity disorder hypothesis of schizophrenia and increase our understanding of the neural mechanisms of schizophrenia.

Differentiation of renal oncocytoma and renal clear cell carcinoma using relative CT enhancement ratio.

BACKGROUND: The difference between renal oncocytomas (RO) and renal clear cell carcinomas (RCCs) presents the greatest diagnostic challenge. The aim of this study was to retrospectively determine if RO and RCCs could be differentiated on computed tomography (CT) images on the basis of their enhancement patterns with a new enhancement correcting method. METHODS: Forty-six patients with a solitary renal mass who underwent total or partial nephrectomy were included in this study. Fourteen of those were RO and 32 were RCCs. All patients were examined with contrast-enhanced CT. The pattern and degree of enhancement were evaluated. We selected the area that demonstrated the greatest degree of enhancement of the renal lesion in the corticomedullary nephrographic and excretory phase images. Regions of interest (ROI) were also placed in adjacent normal renal cortex for normalization. We used the values of the normal renal cortex that were measured at the same time as divisors. The ratios of lesion-to-renal cortex enhancement were calculated for all three phases. The Student's t-test and Pearson's Chi-square test were used for statistical analyses. RESULTS: All RCCs masses showed contrast that appeared to be better enhanced than RO on all contrast-enhanced phases of CT imaging, but there was no significant difference in absolute attenuation values between these two diseases (P > 0.05). The ratio of lesion-to-cortex attenuation in the corticomedullary phase showed significantly different values between RO and RCCs. The degree of contrast enhancement in RCCs was equal to or greater than that of the normal renal cortex, but it was less than that of the normal cortex in RO in the corticomedullary phase. The ratio of lesion-to-cortex attenuation in the corticomedullary phase was higher than the cut off value of 1.0 in most RCCs (84%, 27/32) and lower than 1.0 in most RO (93%, 13/14) (P < 0.05). In the nephrographic phase, the ratio of lesion-to-cortex attenuation was higher than that in the corticomedullary phase in most RO (71%, 10/14), showing a prolonged enhancement pattern; and was lower than that in most RCCs (97%, 31/32), showing an early washout pattern (P < 0.05). In the differentiation of RO from RCCs, the sensitivity was 93%, specificity 84%, positive predictive value 72%, negative predictive value 84%, and accuracy for RO was 87, if the ratio of lesion-to-cortex attenuation in a cortex phase was lower than the cutoff value of 1.0. The sensitivity was 71%, specificity was 97%, positive predictive value was 91%, negative predictive value was 91%, and accuracy for RO was 89%, if the ratio of lesion-to-cortex attenuation in nephrographic phase was higher than that in the corticomedullary phase. CONCLUSIONS: The ratios of renal lesion-to-cortex attenuation ratios may be helpful in differentiating RO from RCCs.

Gastric hepatoid adenocarcinoma: a computed tomography report of six cases.

We describe the computed tomography (CT) imaging findings in six cases (five males and one female; age range 61-78 years; mean age 67.3 years) with histologically proven hepatoid adenocarcinoma of the stomach (HAS). Five of the six patients had elevated serum alpha-fetoprotein levels. The most common type of gross appearance HAS on CT is a polypoid mass (83%, 5/6). The most common contrast enhancement pattern was heterogeneous. All six patients had a regional lymphadenopathy larger than 6 mm in its short axis. Liver metastases (n = 3) were noted. Venous tumor thrombosis was identified in the portal vein (n = 2) of the regions near primary gastric tumors or metastatic masses. Our findings suggest in an elderly, male patients with a large heterogeneous enhancement tumor, the presence of distant metastases, regional lymphadenopathy and characteristically increased serum alpha-fetoprotein levels indicates a high likelihood of HAS.

Assessment of myocardial bridge and mural coronary artery using ECG-gated 256-slice CT angiography: a retrospective study.

Recent clinical reports have indicated that myocardial bridge and mural coronary artery complex (MB-MCA) might cause major adverse cardiac events. 256-slice CT angiography (256-slice CTA) is a newly developed CT system with faster scanning and lower radiation dose compared with other CT systems. The objective of this study is to evaluate the morphological features of MB-MCA and determine its changes from diastole to systole phase using 256-slice CTA. The imaging data of 2462 patients were collected retrospectively. Two independent radiologists reviewed the collected images and the diagnosis of MB-MCA was confirmed when consistency was obtained. The length, diameter, and thickness of MB-MCA in diastole and systole phases were recorded, and changes of MB-MCA were calculated. Our results showed that among the 2462 patients examined, 336 have one or multiple MB-MCA (13.6%). Out of 389 MB-MCA segments, 235 sites were located in LAD2 (60.41%). The average diameter change of MCA in LAD2 from systole phase to diastole phase was 1.1 ± 0.4 mm, and 34.9% of MCA have more than 50% diameter stenosis in systole phase. This study suggested that 256-slice CTA multiple-phase reconstruction technique is a reliable method to determine the changes of MB-MCA from diastole to systole phase.

Hippocampal and thalamic neuronal metabolism in a putative rat model of schizophrenia.

The transcription factor early growth response protein 3 (EGR3) is involved in schizophrenia. We developed a putative rat model of schizophrenia by transfecting lentiviral particles carrying the Egr3 gene into bilateral hippocampal dentate gyrus. We assessed spatial working memory using the Morris water maze test, and neuronal metabolite levels in bilateral hippocampus and thalamus were determined by 3.0 T proton magnetic resonance spectroscopy. Choline content was significantly greater in the hippocampus after transfection, while N-acetylaspartate and the ratio of N-acetylaspartate to creatine/phosphocreatine in the thalamus were lower than in controls. This study is the first to report evaluation of brain metabolites using 3.0 T proton magnetic resonance spectroscopy in rats transfected with Egr3, and reveals metabolic abnormalities in the hippocampus and thalamus in this putative model of schizophrenia.

[Morphological and quantitative evaluation of myocardial bridge and mural coronary artery with 256-slice CT angiography: initial clinical experience].

OBJECTIVE: To determine the morphological characteristics of myocardial bridge and mural coronary artery (MB-MCA) and initially quantify the changes of MB-MCA in diastole and systole phase with multiple-phase reconstruction technique using 256-slice CT angiography (256-slice CTA). METHODS: We retrospectively collected the coronary artery imaging data of 861 patients undergoing 256-slice CTA with suspected or documented coronary artery disease. The images were reviewed by two independent radiologists, the diagnosis of MB-MCA was confirmed when consistency was obtained. The length, diameter and thickness of MB-MCA in the middle segment of LAD (LAD2) in diastole and systole phase were recorded, and changes of MB-MCA were calculated. RESULTS: Among the 861 patients, 150 MB-MCA were found in 131 patients (15.2%). 99 MB-MCA (66.0%) were located in LAD2, the remaining 51 (34.0%) in the other segments of coronary arteries. The average length and thickness of MB was (17.6 ± 5.7) mm and (2.6 ± 0.7) mm, respectively. The average diameter change of MCA in LAD2 from systole phase to diastole phase was (1.2 ± 0.5) mm, and 41% of MCA have diameter stenosis more than 50% in systole phase. CONCLUSION: The changes of MB-MCA from diastole to systole phase could be determined to some extent by 256-slice CTA multiple-phase reconstruction technique.

Effects of formoterol-budesonide on airway remodeling in patients with moderate asthma.

AIM: To evaluate the effect of inhaled formoterol-budesonide on airway remodeling in adult patients with moderate asthma. METHODS: Thirty asthmatic patients and thirty control subjects were enrolled. Asthmatic subjects used inhaled Symbicort 4.5/160 µg twice daily for one year. The effect of formoterol-budesonide on airway remodeling was assessed with comparing high-resolution computer tomography (HRCT) images of asthmatic patients and controls, as well as expression levels of cytokines and growth factors, inflammatory cell count in induced sputum, and airway hyper-responsiveness. RESULTS: The differences in age and gender between the two groups were not significant. However, differences in FVC %pred, FEV(1) %pred, and PC(20) between the two groups were significant. After treatment with formoterol-budesonide, the asthma patients' symptoms were relieved, and their lung function was improved. The WT and WA% of HRCT images in patients with asthma was increased, whereas treatment with formoterol-budesonide caused these values to decrease. The expression of MMP-9, TIMP-1, and TGF-ß(1) in induced sputum samples increased in patients with asthma and decreased dramatically after treatment with formoterol-budesonide. The WT and WA% are correlated with the expression levels of cytokines and growth factors, inflammatory cell count in induced sputum, and airway hyper-responsiveness, while these same values are correlated negatively with FEV(1)/FVC and FEV(1)%. CONCLUSION: Formoterol-budesonide might interfere in chronic inflammation and airway remodeling in asthmatic patients. HRCT can be used to effectively evaluate airway remodeling in asthmatic patients.

[Analysis of the correlation between the degree of GBWT and hemodynamic changes of portal vein system].

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].

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].

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.

Accuracy and reproducibility of assessing right ventricular function with 64-section multi-detector row CT: comparison with magnetic resonance imaging.

BACKGROUND: Right ventricular (RV) function is very important for those patients with respiratory and cardiovascular disorders that can result in RV impairments. Because of complex geometry of the chamber, it is difficult to accurately measure the RV volumetric parameters with conventional imaging modalities. The purpose of this study was to evaluate whether the 64-MDCT can assess RV function with high accuracy and reproducibility when compared to the results with those of MRI. METHODS: Forty-seven consecutive subjects underwent retrospectively ECG-gated 64-MDCT and MRI for assessing the ventricular function. Right ventricular end diastolic and end-systolic volume, stroke volume, and ejection fraction were measured with dedicated cardiac analysis software on 64-MDCT and compared with values measured on MRI which served as the reference standard. Agreement between two modalities was assessed with Bland and Altman analysis and linear regression analysis. Repeated measurements were performed to determine intraobserver and interobserver variability. RESULTS: No significant differences were revealed in calculated RV volumes and EF between the two modalities. Agreement and correlation were similar for RV-EDV (0.4 ± 8.2 ml; r=0.95), RV-ESV (-0.6 ± 4.8; r=0.95), RV-SV (1.1 ± 6.7 ml; r=0.93), and RV-EF (0.9 ± 4.4; r=0.88). The difference of SV of right and left ventricle with 64-MDCT was not statistically significant (p=0.40) and good correlation was obtained (r=0.96). The variability in 64-MDCT measurements was lower than those in MRI. CONCLUSIONS: ECG-gated 64-MDCT can assess the RV function with high accuracy and reproducibility without geometric assumptions about right ventricle.

Correlation of calcium measurement with low dose 64-slice CT and angiographic stenosis in patients with suspected coronary artery disease.

Coronary artery calcium is a sensitive marker of coronary artery disease (CAD). This study was to determine the relationship between coronary calcium score (CCS) and angiographic stenosis on a patient-based or vessel-based analysis. 91 consecutive patients underwent both low dose 64-slice CT calcium scoring scan and conventional angiography of the heart. The total CCS of abnormal coronary angiogram (n=45) was 297.38+/-416.93, whereas that of normal coronary angiogram (n=46) was 5.37+/-9.35 (P<0.001). The CCS and degree of stenosis were moderately correlated on patient-based or vessel-based analysis (r=0.517, 0.521, respectively; both P<0.001). In conclusion, CCS could reflect the degree of vessel stenosis to some extent, but CCS of zero could not rule out CAD.

[Clinical application of 64-slice CT in evaluation of vessel before and after coronary artery bypass graft surgery].

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.

[Assessment of regional left ventricular function with 64 multi-detector row computed tomography].

To evaluate the regional left ventricular function (LVF) and to establish the reference data of LVF parameters in the normal people with retrospective ECG gating 64-detector row CT, ten time phases in the cardiac cycle were reconstructed. Scanning was performed on 42 normal adult, and short axis images of the left ventricular were acquired. Endo-cardium and epi-cardium were delineated along with function parameters based on the cardiac analysis software. End-systolic thickness (EST) was thicker than end-diastolic thickness (EDT) (P<0.05). EDT and EST increased, but thickness decreased from apical, mid-ventricular to basal segments. Statistically significant difference was noted between mid-ventricular and basal segments (P<0.05). EDT, EST, thickness and motion of anterior, lateral and inferior segments were greater than those of septal segments in the same ventricular slices (P<0.05). 64-detector row CT could depict the regional LVF accurately. The LVF parameters of normal adults might be useful in diagnosing abnormal left ventricular function.

[Accuracy of 64-slice multi-detector row CT angiography in the diagnosis of coronary artery lesions].

OBJECTIVE: To determine the accuracy of 64-slice computed tomography angiography (CTA) in the diagnosis of coronary artery lesions. METHODS: We retrospectively collected the coronary artery imaging data of 49 patients who underwent 64-slice CTA and conventional catheter-based selective coronary angiography (SCA) during July 2006 and May 2007. The CTA and SCA diagnosis were compared. RESULTS: The 64-slice CTA enabled the visualization of the entire coronary tree with diagnostic image quality in 46 of the 49 patients. The CTA had a sensitivity of 54.88%, 47.50% and 93.15%, and a specificity of 99.42%, 95.68% and 97.13% for detecting less than 50% stenosis, 50%-75% stenosis, and greater than 75% stenosis, respectively. The overall Pearson's correlation coefficient between the degree of stenosis detected by quantitative SCA and 64-slice CTA was 0.941. CONCLUSION: 64-slice CTA is a good instrument for assessing coronary artery lesions.

[The solitary pulmonary tuberculous cavity and malignant cavity: comparison on multi-detector row CT].

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.

[Influence of cardiac rhythm on image quality of 64-slice multidetector-row CT coronary angiography and clinic value of post-processing technology with image].

OBJECTIVE: To evaluate the influence of cardiac rhythm on 64-slice multi-detector row CT coronary angiography and clinic value of imaged post-processing technology. METHODS: 687 patients with suspected coronary heart disease who underwent 64-slice multi-detector row CT coronary angiography were retrospectively analyzed with their CT images. Four group images of patients were analyzed and compared according to the fluctuation of cardiac rhythm. Multi-phase reconstruction (n = 76) and the ECG-edit software (n = 21) were performed in those patients with arrhythmia. RESULTS: The statistical differences were found among the imaging quality of each group (chi2 = 225.040, P < 0.001). As the fluctuation of cardiac rhythm increased, the quality of CT images dropped down concomitantly. After images processed with ECG-edit software, the quality of CT coronary angiography images got improved (Z = - 3.385, P = 0.001). In 76 patients with multi-phase reconstruction, the image quality of right coronary artery got improved in 40% R-R interval when high quality images couldn't be obtained in 75% R-R interval (Z = - 4.209, P < 0.001). CONCLUSION: Cardiac rhythm is an important factor to affect the CT coronary angiography, but post-processing technology may be useful for improving the imaging quality.