Résumé
Objective To evaluate and compare the imaging quality and diagnostic accuracy of two types of scanning techniques of 256-slice spiral CT angiography, prospective electrocardiogram(ECG)-gated sequence and non ECG-gated high-pitch sequence, used respectively for patients with Stanford type A aortic dissection (AAD) at the root of ascending aorta.Methods A retrospective study was conducted. Sixty-eight patients with AAD were definitely diagnosed by CT angiography were admitted to the Fifth Central Hospital of Tianjin from August 2015 to July 2017, and they were divided into two groups according to different scanning methods: 36 cases of AAD underwent prospective ECG-gated CT angiography (CTA) and 32 patients underwent non ECG-gated high-pitch CTA. A 3-grade scoring system was used to interpret the image quality of the aortic sinus, aortic valve junction zone and coronary artery opening. The CT value and noise value (SD) of aortic root were measured, the image signal to noise ratio (SNR) was calculated and compared with the discovery in exploratory operation; the patients' CTA imaging quality and the coincidence rate of lesion type diagnosis were compared between the two groups.Results All aortic CTA images could meet the diagnostic requirements. The imaging quality scores of aortic sinus, arotic valve junction zone and coronary artery opening images in ECG-gated CTA group were higher than those in non ECG-gated high-pitch CTA group (aortic sinus: 2.94±0.23 vs. 1.89±0.67, sinuscanal junction zone: 2.94±0.23 vs. 1.83±0.70, coronary artery opening images: 2.86±0.35 vs. 1.31±0.52, allP < 0.01); comparisons between the ECG-gated CTA group and non- ECG-gated CTA group in objective indexes, CT value, arotic SD value and SNR at the root of ascending aorta showed there were no statistically significant differences [the value of CT (HU): 425.20±94.38 vs. 439.29±86.78, the SD value of aorta (HU): 22.85±9.40 vs. 26.40±9.41, SNR: 21.23±8.16 vs. 19.70±9.98, allP > 0.05]. The coincidence rate between the diagnosis of AAD at the root of ascending aorta and the discovery in the exploratory operation in ECG-gated CTA group was higher than that in non ECG-gated CTA group [94.4% (34/36) vs. 68.8% (22/32),P < 0.01].Conclusion The diagnostic accuracy and image quality of AAD root of ascending aorta in prospective ECG-gated CTA group were significantly higher than those in non ECG-gated CTA group.
Résumé
Objective To evaluate the clinical value of cardiovascular dual-phase scan of 256-slice spiral CT in diagnosis of left atrial appendage (LAA) thrombus before radiofrequency ablation in patients with atrial fibrillation. Methods A prospective study was conducted. Thirty-six patients with atrial fibrillation being prepared to undergo radiofrequency ablation admitted to the Fifth Central Hospital of Tianjin from October 2015 toJuly 2016 were enrolled, they were scanned using dual-phase cardiovascular protocol of 256-slice spiral CT, and then trans-esophageal echocardiography (TEE) was performed for the definite diagnose of thrombus. In the first phase of cardiac CT, the intelligent tracking method was used to determine the delayed time; in the second phase cardiac CT scan, 85 seconds was confirmed as the delayed time; TEE as the golden standard was used to evaluate the value of dual-phase CT in definite diagnosis of LAA thrombus.Results LAA low density filling defect was discovered in 5 patients in the first phase CT scan, the CT scan in the second phase, the filling defect still existed, and the diagnosis of LAA thrombus in 3 patients was made (of them 2 cases after TEE examination were diagnosed definitely as LAA thrombus, and the echo in 1 case was smoke-like on TEE, being at pre-thrombus status), 2 cases were confirmed as pseudo-filling defects (afterwards, their diagnosis was confirmed as pre-thrombus status because the echo shown on TEE was smoke-like). Two patients were confirmed as true thrombi on TEE, and there were 3 patients diagnosed as pre-thrombus state by TEE because of their echo smoke-like. TEE was used as the golden standard for diagnosis of thrombus, the following indexes could be calculated: in the first phase, the sensitivity of using CT scan to diagnose LAA thrombus was 100.0%, the specificity 91.2%, positive predictive value (PPV) 40.0%, and negative predictive value (NPV) 100.0%; while in the second phase of using CT scan for diagnosis of LAA thrombus, the above indexes were 100.0%, 97.1%, 66.7%, 100.0% respectively; the CT Kappa coefficient of the second-phase was larger than that of the first-phase CT (0.898 vs. 0.739), the difference being statistically significant (P < 0.05).Conclusions Dual-phase cardiovascular protocol of CT can detecte of LAA thrombus/pre-thrombus state, the PPV is significantly elevated after the second phase of CT scan for diagnosis of thrombus, and the consistency between the second phase CT diagnosis of thrombus and TEE diagnosis is higher than that between the first phase CT and TEE, therefore, using dual-phase cardiovascular protocol of 256-slice spiral CT in diagnosis of LAA thrombus in patients with atrial fibrillation before radiofrequency ablation has relatively high application value.
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Objective To explore the application value of 256 slice helical multi phase CT scan-ning and three-dimensional reconstruction in the diagnosis of malignant tumor of colorectal obstruction. Methods Using 256 slice spiral CT scanning and three-dimensional reconstruction of multi period in 42 ca-ses of malignant tumor patients with colorectal obstruction, the results and pathological results were analyzed and the postoperative stage.Results Forty-two cases of malignant tumors of colorectal obstruction, 256 slice spiral CT could well reflect the situation of location, range, degree, peripheral intestinal lymph node and distant metastasis, CTA could show the tumor supplying artery and branch sources, on the tumor loca-tion and overall accuracy.Conclusions 256 layer spiral CT scan and three dimensional reconstruction technology is accuracy for clinical diagnosis on malignant tumor of colorectal obstruction.
Résumé
Objective To evaluation the anatomy relationship between thoracic artery and coronary artery by using 256 layer spiral CT angiography. Methods The angiographic images of thoracic aortic and coronary artery angiography were re?vealed in 200 patients with chest pain. Values of the major branch length, diameter, length of the aorta-coronary artery by?pass on both sides of the thoracic artery and coronary artery were measured. Results The diameter of thoracic artery was (2.52±0.38) mm, and the length of thoracic artery from the starting point to terminal was (190.12 ±1.90) mm. There were no significant differences in the thoracic artery lumen diameter and length between both sides. The inner diameters of left anteri?or descending coronary artery, left circumflex, diagonal branch, right coronary artery and the posterior interventricular branch were (2.82 ±0.25), (2.60±0.12), (2.22±0.25), (3.02±0.27) and (2.35±0.35) mm respectively. There were no significant differences in thoracic artery diameters except for the right coronary artery diameter, which was higher than that of the thorac?ic artery. About free transplantation the length from 2cm above in the ascending aorta starting to the halfway point of anterior descending coronary artery, to the atrioventricular node along the left circumflex way, to the atrioventricular node along the right coronary artery and from the atrioventricular node to halfway point of posterior interventricular branch was shorter than that of thoracic artery (P0.05). The length from the thoracic artery start department to the left-hand atrioventricular node, to the right coronary artery atrio?ventricular node was higher than that of the thoracic artery length (P<0.05). Conclusion The branches of internal thoracic artery and coronary artery are similar. About situ transplantation is suitable for the wall blood vessels before the heart. With free thoracic artery transplantation, its length can meet any bridging from the ascending aorta to the coronary arteries.