Coronary angiography with dual source computed tomography: initial experience / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To explore the scan technique and image quality of coronary angiography with dual source computed tomography (CT) without oral metoprolol preparation.</p><p><b>METHODS</b>Plain and enhanced dual source CT coronary angiography without oral metoprolol preparation was prospectively performed in 600 patients. Calcium scoring with plain scan images as well as multi-planar reconstruction (MPR), maximum intensity projection (MIP), and volume rendering technique (VRT) reconstruction with enhanced scan images were performed in all cases. The scan technique and post-reconstruction experience was summarized. The image quality was classified as 1 to 4 points, and coronary segments classified according to the American Heart Association standards were evaluated.</p><p><b>RESULTS</b>The average calcium score of the 600 cases was 213.6 +/- 298.7 (0-3,216.5). The average heart rate of the enhanced scan was 82.1 +/- 16.2 (47-139) bpm. The post-reconstruction methods with which coronary segments could be shown as best as possible consisted of single phase reconstruction method, two or more phases supplemented method, and electrocardiogram editing method. Altogether 8,457 coronary segments were evaluated, among which 97.2% were evaluated as point 1, 1.7% point 2, 0.5% point 3, and 0.6% point 4. The coronary segments in 261 cases were completely normal, while 360 segments were diagnosed with < 50% stenosis and 625 segments with > or = 50% stenosis.</p><p><b>CONCLUSIONS</b>Excellent coronary artery image can be obtained with dual source CT in patients with any heart rate without oral metoprolol preparation. Heart rate is not a major source of the artifact, coronary segments can be well shown with single or multiple-phase reconstruction method.</p>

Comparison of coronary artery bypass graft imaging between 64-slice and 16-slice spiral CT / 中国医学科学院学报

<p><b>OBJECTIVE</b>To compare the coronary artery bypass graft (CABG) imaging between 16-slice spiral CT and 64-slice spiral CT.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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% .</p><p><b>CONCLUSIONS</b>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.</p>

Using of multislice helical CT colonography in patients with malignant lesions of colon / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the techniques and clinical applications of multislice helical computed tomography (CT) colonography in colonic lesions.</p><p><b>METHODS</b>Fifty-nine patients with malignant lesions of colon underwent volume scanning using multislice helical CT. Four types of reconstruction including CT virtual colonoscopy (CTVC), shaded surface display (SSD), Raysum, and multiple planar reconstruction (MPR) were used for image post-processing. The results were compared with those of colonoscopy and pathology.</p><p><b>RESULTS</b>Multislice helical CT colonography detected 54 colorectal carcinomas, 4 adenomas with focal carcinoma, 1 non-Hodgkin's lymphoma (NHL). The lesions' number, size, location, morphology, stricture of intestinal cavity, infiltration, and metastasis were shown satisfactorily by multislice helical CT colonography. Whole colon could be shown in all patients. CT colonography displayed 4 synchronous colonic tumors, 1 ascending colon carcinoma combined with left renal carcinoma among 54 patients with colonic carcinomas. The accuracy of location of CT colonography was 100%. There were 9 cases that CT showed the tumor location was different from the finding of conventional colonoscopy, while all of the CT location were proven exact by operation. CT colonography also displayed the infiltration of serous layer and fatty tissue in 45 cases; 21 cases matched the pathological results in all the 24 cases of suspicious lymph node metastasis, the sensitivity was 87.5%, the specificity was 90.6%; 9 cases hepatic metastasis, 2 ovarian metastasis, and 1 double adrenal gland metastasis.</p><p><b>CONCLUSIONS</b>Multislice helical CT colonography is effective in preoperative diagnosis, location, stage, and making treatment plan of colorectal carcinoma. It can display the portion not seen during colonoscopy and may have an adjunctive role.</p>

Techniques and clinical applications of 16 multislice helical CT in colonic diseases / 中国医学科学院学报

<p><b>OBJECTIVE</b>To evaluate the techniques and clinical applications of 16 multislice helical CT in colonic lesions.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSIONS</b>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.</p>

Non-invasive imaging of coronary artery with 16-slice spiral computed tomography / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To evaluate the value of 16-slice spiral CT in the demonstration of coronary artery and in the diagnose of coronary artery stenosis.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>