Biomedical subjects

Wen-min Zhao

Publications and source records attributed to Wen-min Zhao.

12 recordsLinked to original sources

PubMed2006

[CT perfusion in evaluation of cerebral hemodynamics in carotid artery stenosis].

OBJECTIVE: To study the clinical value of multi-slice spiral CT (MSCT) perfusion technique in evaluation of cerebral hemodynamics in patients with severe carotid stenooclusive lesions. METHODS: Twenty-three patients with severe carotid stenosis were enrolled for evaluation of cerebral hemodynamics, including 12 patients with carotid occlusion and 11 with severe carotid stenosis (> 70%). Among them, 16 patients had multiple arterial diseases, including contralateral carotid stenosis, vertebral arteries stenosis, and cerebral arteries stenosis or occlusion. All patients received CT perfusion examination. Ten normal persons received CT perfusion were regarded as the control group. RESULTS: Cerebral perfusion was bilaterally symmetrical in 10 normal persons. While in the patients group, cerebral hemodynamic impairments ipsilateral to the stenosis side were found by CT perfusion in 17 patients, including an delay of time to peak (TTP) (17 patients), increase of cerebral blood volume (CBV) (7 patients), and decrease of cerebral blood flow (CBF) (4 patients). No significant difference was found between occlusion group (n = 8) and stenosis group (n = 9) (P = 0.640), but incidences of hemodynamic impairment were significantly higher in multiple arterial diseases group (n = 14) than single arterial disease group (n = 3) (P = 0.045). CONCLUSION: CT perfusion technique can sensitively reveal the cerebral hemodynamic impairments in patients with severe carotid stenooclusive diseases, and therefore valuable for clinical application.

Adult↗

PubMed2006

[Diagnosis of Takayasu's arteritis affecting carotid arteries with multi-slice spiral CT].

OBJECTIVE: To explore changes in the carotid arteries in Tarkayasu arteritis (TA) with computed tomographic angiography (CTA). METHODS: The common carotid artery intima-medial thickness (CCA-IMT) in 20 common carotid arteries (CCAs) in 10 controls and 40 CCAs in 20 patients with TA were analyzed and compared. RESULTS: Contrast-enhanced CT scanning combined with the application of 3D reconstruction clearly showed the carotid vascular luminal abnormalities, such as stenosis, occlusion, dilation, and aneurysm formation. CCA-IMT increased in all the patients with TA affecting carotid arteries. CCA-IMT was significantly larger in the patients than in controls [(0.36 +/- 0.13) cm vs. (0.03 +/- 0.02) cm, P < 0.05] , and was significantly larger in patients with active diseases than in those without active diseases [(0.44 +/- 0.09) cm vs. (0.24 +/- 0.10) cm, P < 0.05]. CONCLUSION: CCA-IMT increases in TA affecting carotid arteries, especially in active diseases.

Adolescent↗

PubMed2006

[Comparison of coronary artery bypass graft imaging between 64-slice and 16-slice spiral CT].

OBJECTIVE: To compare the coronary artery bypass graft (CABG) imaging between 16-slice spiral CT and 64-slice spiral CT. METHODS: Totally 27 patients with CABG received multi-slice spiral CT imaging and the results were retrospectively analyzed. Among them, 8 patients received 16-slice spiral CT scanning, 19 patients received 64-slice spiral CT scanning. RESULTS: The evaluability rates of 64-slice spiral CT in evaluating the proximal anastomosis, bypass graft, distal anastomosis, and distal blood vessel were 100%, 100%, 90.2%, and 93.9%, respectively, while those of 16-slice spiral CT were 92.3%, 95.2%, 90.0%, and 90.0%, respectively. The patency rates of the above four aspects of 64-slice spiral CT were 66.7%, 70.0%, 71.7%, and 70.0%, respectively, while those of 16-slice spiral CT were 83.3%, 85.0%, 83.3%, and 88.9% . CONCLUSIONS: 64-slice spiral CT is superior to 16-slice spiral CT in CABG imaging. It can be used as a non-invasive tool for the post-operative follow-up of CABG.

Aged↗

PubMed2006

[Comparison of coronary angiography between 64-slice and 16-slice spiral CT].

OBJECTIVE: To compare the image quality and visibility of arteries of 64-slice spiral coronary CT angiography (CTA) with those of 16-slice spiral coronary CTA, and to evaluate the diagnostic accuracy of 64-slice spiral CT for the assessment of coronary artery stenosis. METHODS: Totally 100 patients (Group A) with suspected coronary artery diseases (CAD) were examined by 64-slice spiral CT, 48 of whom also underwent conventional coronary angiography (CAG). Another 100 patients (Group B) with suspected CAD were studied by 16-slice spiral CT. Patients with a heart rate above 70 bpm received oral beta-blockers before the scan. Data were retrospectively analyzed and reviewed by two observers. Image quality was assessed by using a 3-point grading scale from excellent (1) to non-assessable (3) and the rate of displayed coronary branches was calculated. The left main artery (LM), left anterior descending artery (LAD), circumflex artery (CX), and right coronary artery (RCA) were screened for the presence of over 50% stenosis. RESULTS: The mean heart rates of two groups showed no significant difference [(61 +/- 8) bpm vs. (61 +/- 7) bpm, P > 0.05]. The mean scan time of Group A was significantly shorter than that of Group B [(11.9 +/- 0.9) s vs. (22.2 +/- 1.1) s, P < 0.01]. In the evaluation of image quality, better results were obtained in Group A than in Group B (1.20 +/- 0.47 vs. 1.37 +/- 0. 63, P < 0.05). The visibility of proximal arteries was similar between two groups, while the visibility of some distal arteries and small branches was found higher in Group A than in Group B (LAD distal 92% vs. 48%, CX distal 98% vs. 89%, the first obtuse marginal (OMI) 93% vs. 84%, cone branch (CB) 86% vs. 71%, P < 0.05). Compared with CAG, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 64-slice spiral coronary CTA to identify over 50% stenosis were 94.9% (56/59), 93.2% (124/133), 86.2% (56/65), and 97.6% (124/127), respectively. CONCLUSIONS: With higher temporal and spatial resolution, 64-slice spiral CT provides improved image quality and visibility of small branches as compared with 16-slice spiral CT. 64-slice spiral coronary CTA allows reliable non-invasive diagnosis of obvious coronary artery stenosis.

Aged↗

PubMed2006

[Assessment of coronary stent lumen visibility and patency by 64-slice spiral CT angiography].

OBJECTIVE: To evaluate the clinical value of assessment of coronary stent patency by 64-slice spiral CT coronary angiography. METHODS: Totally 29 patients (59 stents) were investigated using a retrospective ECG-gated enhanced scan by 64-slice spiral CT at a mean interval of (28.4 +/- 21.2) months after coronary stent implantation. Axial multi-planar reconstruction (MPR) of the stents and curved-planar reconstruction (CPR) through the stents were evaluated for image quality on a 5-point scale (1 = excellent, 5 = uninterpretable) and lumen diameter. Stent lumen diameter was compared with the vessel diameter proximal of the stents to assess the in-stent lumen visibility. Conventional coronary angiography was performed in 5 patients, and 9 stents were evaluated. RESULTS: The image quality was good to excellent on average (scores: 1.94 +/- 0.84), depending on heart rate, breath movement, and stent location. Stent lumen was visible, on average a percentage off (76.1 +/- 11.1)% of the lumen diameter. All the 9 stents were correctly detected as being patent, which was confirmed by conventional coronary angiography. CONCLUSION: 64-slice spiral CT is a useful tool to assess the coronary stent patency.

Adult↗

PubMed2006

[Assessment of global left ventricular function with multi-slice spiral computed tomography].

OBJECTIVE: To investigate the value of multi-slice spiral computed tomography (MSCT) in the determination of global left ventricular function. METHODS: Twenty-nine patients with confirmed or suspected coronary heart diseases were imaged with a contrast-enhanced retrospective electrocardiogram (ECG) -gated technique on a 64-slice spiral CT scanner. The data sets were reconstructed at both end-diastolic and end-systolic phases in order to measure left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), left ventricular stroke volume (LVSV), and left ventricular ejection fraction (LVEF). The results were compared with corresponding values obtained from conventional left ventriculography (LVG). RESULTS: LVEDV, LVESV, LVSV, and LVEF obtained with 64-slice spiral CT were significantly correlated with the LVG data (r = 0. 887-0.956, P < 0.001). According to the Bland-Altman approach, the mean differences for LVEDV, LVESV, LVSV, and LVEF were -2.3 ml, 4.1 ml, -6.4 ml, and - 3.5%, respectively. The limits of agreement for LVEDV, LVESV, LVSV, and LVEF were -27.2-22.4 ml, -10.2-18.4 ml, -26.4-13.6 ml, and -9.8%-3.0%, respectively. CONCLUSION: MSCT has clinically acceptable agreement with LVG for the quantification of global left ventricular function.

Adult↗

PubMed2006

[Application of multi-slice spiral CT in the diagnosis of pulmonary hypertension].

OBJECTIVE: To evaluate the utility of multi-slice spiral CT in the diagnosis of pulmonary hypertension. METHODS: The clinical and multi-slice spiral CT data of 22 patients with pulmonary hypertension were retrospectively analyzed. The diagnoses included chronic thromboembolic pulmonary hypertension (CTEPH) (n = 9), primary pulmonary hypertension (PPH) (n = 7), connective tissue diseases (n = 2), portal-pulmonary hypertension (n = 2), eosinophilia-myalgia syndrome (n = 1), and fibrosing mediastinitis (n = 1). Lung parenchyma, such as ground-glass opacity, mosaic attenuation and septal thickness, mediastinum, pulmonary vascular, right ventricular enlargement and interventricular septum displacement were evaluated on CT. RESULTS: CT pulmonary angiography (CTPA) accurately diagnosed 95% of pulmonary hypertension and the signs of right ventricular dysfunction. Pulmonary embolism was found in 9 patients. The incidence of mosaic attenuation was significantly higher in CTECH than in PPH (P = 0.034). CONCLUSION: CTPA can accurately diagnose pulmonary hypertension and thereby provide useful information for the etiological diagnosis.

Adult↗

PubMed2006

[Perfusion characteristics of normal pancreas and insulinoma on multi-slice spiral CT].

OBJECTIVE: To investigate the perfusion characteristics of normal pancreas and insulinoma on multi-slice spiral CT (MSCT). METHODS: Totally 21 subjects with suspected insulinoma were enrolled. Sixteen-slice spiral CT was used for perfusion scan following a standard contrast-enhanced scan. The surgical and pathological outcomes were collected for comparison. Perfusion characteristics, including blood flow (BF), patlak blood volume (pBV), time to peak (TTP), permeability, and peak enhancement (PE) of insulinomas and normal pancreas parenchyma were analyzed based on the MSCT data sets subsequently. RESULTS: Benign insulinoma was pathologically confirmed in 12 out of the 21 subjects, while the remaining 9 subjects were normal. Technical failures were experienced in 2 (9.5%) subjects. In both normal and tumor-suffered subjects (n = 19), perfusion parameters of normal pancreatic parachyma were measured as follows: BF (p) = 104. 9 +/- 28.9, pBV (p) = 166.4 +/- 41.8, TrP (p) = 133.3 +/- 24.4, Permeability (p) = 81.3 +/- 24.4, and peak enhancement (p) = 121.3 +/- 31.1. In subjects with insulinoma (n = 11), perfusion parameters of tumor tissue were measured as follows: F (i) = 206.5 +/- 42.2, BV (i) = 315.9 +/- 79.0, TFP (i) = 123.2 +/- 18.8, Permeability (i) = 102.5 +/- 54. 8, and peak enhancement (i) = 221.3 +/- 48.5. Results of F, BV, and peak enhancement in these two kinds of tissue showed significant differences (P < 0.01), while there were no significant difference (P > 0.05) in TTP and permeability between normal pancreatic parenchyma and insulinoma. CONCLUSIONS: Benign insulinoma has perfusion characteristics of increased blood flow and blood volume, but its TTP is consistent with normal pancreas and has normal permeability. MSCT allows further understanding of the blood flow of the normal pancreas and its benign tumor insulinoma.

Adult↗

PubMed2004

[Non cholangio-contrast cholangiopancreatography using multi-slice spiral CT].

OBJECTIVE: To investigate the feasibility of multi-slice spiral CT (MSCT) for cholangiopancreatography without cholangio-contrast. METHODS: Ten patients without any digestion system diseases and 24 patients with suspected pancreatic malignancy received the 16-slice spiral CT multi-phased contrast-enhanced scanning. The images of patients without any digestion system diseases and cancer-suffered patients were curved reformatted (CR) technique to perform the structure of pancreatic duct, common bile duct, and ampulla. The cholangiopancreatical systems of the cancer suffered patient were reconstructed through volume rendering technique (VRT), minimum intensity projection (MinIP), and indirect minimum intensity projection (IMinIP). The results of patients without any digestion system diseases in curved multiplanar reconstruction were analyzed; meanwhile display rates of the pancreatic duct, common bile duct, and ampulla were evaluated. RESULTS: of the four different cholangiopancreatographies were compared. RESULTS: The display rate of pancreatic duct in the CR images was 90.0 (9/10) with an average diameter of (2.63 +/- 0.51) mm. Sub-pancreatic duct could be seen in 88.9% (8/9) of them. The display rate of common bile duct in the CR images was 100% (10/10) with an average diameter of (7.45 +/- 1.12) mm. The display rate of ampulla was 60.0 (6/10), which was affected by the filling status of duodenum. The cholangiopancreatography using CR, VRT, MinIP, and IMinIP for patients with pancreatic cancer reveal the whole pancreatic and common bile duct, and the modality of distal obstructed bile duct. The result showed that IminIP got the best outcome (98.6%), while VRT got the worst (68.1%). CONCLUSION: The negative CT cholangiopancreatography is a simple and non-invasive examination. It reflects both the 3-dimensional cholangio-pancreatic anatomical structure and its adjacent condition. It has curtain clinical application values, especially for patients with obstructed duct system.

Adult↗

PubMed2004

[Techniques and clinical applications of 16 multislice helical CT in colonic diseases].

OBJECTIVE: To evaluate the techniques and clinical applications of 16 multislice helical CT in colonic lesions. METHODS: Eighty-one patients including 54 colorectal carcinomas, 5 adenomas, 1 non-Hodgkin's lymphoma, 6 inflammatory bowel diseases, and other 15 cases underwent volume scanning using 16 multislice helical CT. Four types of reconstruction included multiple planar reconstruction, shaded surface display, raysum, and CT virtual colonoscopy. RESULTS: Complete colon could be shown in all patients. The lesions' morphology, number, size, location, intestinal cavity, pericolonic changes, and other abdominal organs were satisfactorily shown by CT. CONCLUSIONS: Sixteen multislice helical CT colonography is a valuable imaging technique for detecting colonic diseases. It is effective in diagnosis and treatment planning. It can display the portions of colon that is inaccessible at colonoscopy.

Adenocarcinoma↗

PubMed2004

Non-invasive imaging of coronary artery with 16-slice spiral computed tomography.

OBJECTIVE: To evaluate the value of 16-slice spiral CT in the demonstration of coronary artery and in the diagnose of coronary artery stenosis. METHODS: Plain and enhanced CT scans were performed with a 16-slice CT scanner (Sensation 16, Siemens, Germany) in 230 patients with suspected coronary heart disease (CHD). Parameters of the plain scan were: 120 kV, 133 mA, slice collimation 16 mm x 1.5 mm, rotation time 0.42 seconds, increment 1.5 mm, and slice width 3 mm. Parameters of the enhanced scan were: 120 kV, 500 mA, slice collimation 16 mm x 0.75 mm, rotation time 0.42 seconds, increment 0.5 mm, and slice width 1 mm. Enhanced CT scan was performed with a rapid intravenous injection of 100 mL iothalamate meglumine (Ultravist) (370 mgI/mL) or Omnipaque (350 mgI/mL) and 30 mL 0.9% NaCl chaser bolus at a flow rate of 3.5 mL/s. Calcium scoring with plain scan images and two and three dimensional reconstruction with enhanced scan images were made in all cases, among which 30 cases underwent conventional coronary angiography. Demonstration of coronary arteries and their stenosis were evaluated and the factors that might influence the image quality were analyzed. RESULTS: Coronary calcium scores were calculated and coronary artery was demonstrated in our study. In the evaluation of image quality with volume rendering technique (VRT) images, 78.3% of the images were of the first class, 12.2% the second class, and 9.6% the third class. Multi-planar reconstruction (MPR) and maximal intensity projection (MIP) were better than VRT in the demonstration of small branches. The image quality was related to the heart rate, with or without arrhythmia, and breath-hold ability of patients. Comparative study of the stenosis of coronary arteries in 30 cases showed that the sensitivity and specificity of 16-slice coronary CT angiography (CTA) to diagnose significant stenosis were 95.8% and 94.8% respectively. CONCLUSION: As a non-invasive and quick method, 16-slice coronary CTA is sensitive and specific to diagnose the stenosis of coronary arteries and can be used as a screening method in the diagnosis of CHD.

Coronary Angiography↗

PubMed2003

[Coronary angiography with sixteen-slice spiral CT: an initial study].

OBJECTIVE: To evaluate the scanning technique and primary clinical value of sixteen-slice spiral CT coronary angiography. METHODS: Plain and enhanced sixteen-slice spiral CT imaging was performed in 69 patients, including 64 cases of suspected coronary heart disease and 5 cases of coronary stent. Calcium scoring with plain scan images and MPR, MIP and VRT reconstruction with enhanced scan images were made in all cases, among which 10 underwent conventional coronary angiography. The demonstration and stenosis of coronary arteries were evaluated. The factors influencing the image quality were analyzed. Additional MPR and MIP reconstruction of slices perpendicular to the stent and virtual endoscopy of stent were made in 7 stents of the 5 cases of coronary stent. The patency of the stents was evaluated. RESULTS: A four-step scanning procedure was devised. Coronary calcium score could be got by plain scanning with sixteen-slice spiral CT angiography. All of the primary, most of the secondary and tertiary, and part of the fourth level branches of coronary artery could be shown isotropically with MPR, MIP and VRT reconstruction images of enhanced scanning. MPR and MIP were better than VRT in demonstrating small branches. Evaluated by VRT image, the image quality of 79.7% of the patients were first class, 10.1% second class, and 10.1% third class. The image quality was correlated to the contrast concentration in the root of aorta, heart rate, existence or absence of arrythmia, and the patient's breath-holding ability. Stenosis of coronary arteries was evaluated by sixteen-slice spiral CT imaging in 10 cases, with a result comparable to that by conventional coronary angiography. The stents were well shown, six stents being evaluated as patent, while one not. CONCLUSION: Sixteen-slice spiral CT coronary angiography is a noninvasive, simple and good method. Coronary calcium score and coronary artery stenosis can be evaluated with one study. The patency of stents can also be evaluated.

Adult↗