数字减影血管造影对原发性肝癌的术前评价

目的评价数字减影血管造影（DSA）对我国原发性肝癌术前的意义。方法回顾分析1998年5月～2007年5月1000例原发性肝癌术前的DSA影像与多层螺旋CT（MSCT）及彩超检查结果。结果三种方法发现肝癌1000例,直径3em以上的700例肝癌中,DSA发现670例;240例小肝癌中DSA发现202例;30例弥漫性肝癌中,DSA发现28例;900个子灶中,DSA发现890个;440例门脉癌栓中,DSA发现362例;490例动静脉瘘、动门脉瘘中,DSA发现482例。结论DSA检查对原发性肝癌的术前评价具有不可替代的作用。     

The use of digital subtraction angiography in evaluating pulmonary abnormalities in children

In nine cases of pulmonary lesions in children, the diagnostic procedure of digital subtraction angiography was used with minimal invasiveness. Vascular anatomy was additionally confirmed by angiocardiography in four cases. One patient had a thoracotomy with removal of a nonvascular mass, whereas the other four patients, based on information provided by the digital subtraction angiogram, continued to be followed clinically. Using a peripheral vein for injection, intravenous subtraction angiography proved to be a satisfactory method of evaluating pulmonary vascular lesions and provided considerable information. Although other imaging modalities, including angiocardiography, computerized axial tomography scanning, or radionuclide studies, may be necessary for confirmation of the diagnosis, digital subtraction angiography should be considered in the work-up of pulmonary abnormalities in the pediatric patient. Five of the nine case studies are presented as appropriate examples.     

Lung cancer: Preoperative pulmonary evaluation of the lung resection candidate

Lung resection provides the best chance of cure for individuals with early stage non-small cell lung cancer. Naturally, lung resection will lead to a decrease in lung function. The population that develops lung cancer often has concomitant lung disease and a reduced ability to tolerate further losses in lung function. The goal of the preoperative pulmonary assessment of individuals with resectable lung cancer is to identify those individuals whose short- and long-term morbidity and mortality would be unacceptably high if surgical resection were to occur. Pulmonary function measures such as the forced expiratory volume in 1 second and the diffusing capacity for carbon monoxide are useful predictors of postoperative outcome. In situations in which lung function is not normal, the prediction of postoperative lung function from preoperative results and the assessment of exercise capacity can be performed to further clarify risks. Published guidelines help to direct the order of testing, permitting us to offer resection to as many patients as possible.     

Cardiac applications of digital subtraction angiography

Recent developments in digital computer technology have enabled direct digital acquisition of radiographic images at spatial and temporal resolutions similar to that of cineradiography. Initially intended as a means of performing peripheral angiography, digital subtraction angiography has been increasingly applied to cardiac catheterization procedures. Advantages of cardiac digital substraction angiography include the capabilities to: immediately replay, magnify and enhance angiographic studies during coronary artery interventions, perform left ventriculography with peripheral contrast injections and direct left ventriculography with substantially reduced contrast doses, perform bypass graft visualization using aortic root contrast injection, assess relative regional coronary blood flow and facilitate the quantification of ventriculographic and coronary stenosis parameters. Clinical comparisons of standard cineradiographic and digital angiographic studies have demonstrated very similar results.     

Densitometric studies in digital subtraction angiography: assessment of pulmonary and myocardial perfusion

The technical improvement of digital imaging systems has provided for roentgen densitometric analysis of radiographic image sequences. Thereby, regional and temporal measurements of the amount of contrast medium have been performed for comparative studies in angiocardiography. The use of digital image subtraction for densitometric evaluation is specifically advantageous because misregistration by motion artefacts can be circumvented. Furthermore, enhancement of faintly opacified circulatory structures assists in the detection and outlining of the regions of interest. Methods of digital densitometry are described utilizing large "densitometric areas" for the evaluation of pulmonary perfusion symmetry. Similarly, coronary flow distribution data have been established in experimental studies. Regional measurements of myocardial contrast accumulation allowed for perfusion studies in absolute units of volume flow (ml/min) of the three main coronary arterial vessels. Future application of the latter technique is expected to facilitate coronary flow reserve measurements in the clinical setting.     

Preoperative evaluation in surgical treatment of lung cancer

The most effective treatment option of a patient with lung cancer is lung resection. The most important problem in this modality of treatment is postoperative complications. In order to decrease the mortality and morbidity, it is necessary to predict potential complications with cardiopulmonary evaluation. In this review, we reviewed the methods to assess cardiac and pulmonary functions of a patient undergoing lung resection under the lights of recent literature.     

Left ventricular dual-energy digital subtraction angiography: a motion immune digital subtraction technique

Digital subtraction angiography (DSA) allows quantitative analysis of ventricular function via densitometric and parametric imaging techniques. However, DSA is limited by the artifacts in temporal subtraction images that result from patient and cardiac motion. Dual-energy subtraction imaging is insensitive to motion. This study evaluated the initial application of dual-energy subtraction in cardiac patients. The image quality of dual-energy subtraction left ventriculograms obtained from a pulmonary artery injection of contrast was assessed in 13 patients, ranging in weight from 54 to 100 kg. The dual-energy images were compared with left ventricular images obtained using standard left ventricular injection cine angiography. End-systolic and end-diastolic ventricular volumes calculated from the cine (C) and dual-energy (DE) images using the Area-Length method were compared. The resulting regression line was DE=0.98 C + 7.0 ml, and the r value was 0.987. Dual-energy subtraction provided good left ventricular visualization, free from misregistration artifacts, even during patient motion.     

The use of intravenous digital subtraction angiography in the evaluation of tetralogy of Fallot

Sixteen patients with tetralogy of Fallot were studied with intravenous digital subtraction angiography (DSA). Of these, 11 were males and five were females, ranging in age from 26 months to 54 years, with a mean age of 22 years at the time of the initial study. Twenty-two DSA studies were performed in the 16 patients, in seven patients preoperatively, in 12 patients postoperatively, and in three patients both pre- and postoperatively. In the seven patients studied preoperatively, all DSA studies were considered technically adequate as corroborative evidence in the diagnosis of tetralogy of Fallot. All associated cardiac abnormalities were adequately demonstrated. The 16 postoperative studies on 12 patients were performed to evaluate the adequacy of the surgery and/or postoperative complications. These studies were judged as technically satisfactory. The authors utilized intravenous DSA in the pre- and postoperative evaluation of 16 patients with tetralogy of Fallot and found that reliable angiographic information was provided and that this technique may serve as a useful adjunct with other noninvasive and invasive tests in the preoperative and postoperative evaluation of these patients.     

Left ventricular imaging by digital subtraction angiography

Summary Digital radiography is a rapidly developing new approach to cardiovascular imaging that converts radiographic and fluoroscopic video images into digital format for subsequent image enhancement analysis, and storage. Left ventriculography can be performed by this method using either intravenous or low-dose intraventricular contrast administration. Advantages over standard radiography include reduced radiation and contrast medium burden, visualization of very low contrast medium concentrations, and an image format that can be directly analyzed by quantitative techniques. As these cardiac applications are developed and improved archiving is implemented, it is likely that the digital left ventriculography will replace standard cardiac angiography.     

A comparative study of intravenous digital subtraction angiography and ventilation-perfusion scans in suspected pulmonary embolism

We observed 102 patients suspected of having pulmonary emboli (PE) who underwent ventilation-perfusion (V/Q) lung scintigraphy and IV digital subtraction angiography (DSA). Only five DSA studies were inadequate for interpretation. In 81 of the remaining 97 patients (83.5 percent) the results of both studies correlated regarding the probability of PE. In 50 patients the results of both studies were highly suggestive of PE; in 31 patients DSA and V/Q were normal or classified as low probability of PE. There was disagreement in 3/97; in 13/97 one or both studies were nondiagnostic. The clinical data of these 16 patients are given. Conventional catheter pulmonary angiography was indicated in 11/102 patients to establish a firm diagnosis of PE. The results of V/Q and DSA correlated in 83 percent (49/59) of patients without chronic obstructive pulmonary disease (COPD) and in 84 percent (32/38) of the patients with COPD.     

Flow velocity measurement using digital subtraction angiography for hemodynamic evaluation in arterial occlusive disease

A method for mean flow velocity measurement using digital subtraction angiography (DSA) was evaluated, along with the results of phantom and animal experiments. The validity of its clinical use was studied by applying this technique in the arteries and bypass grafts in patients with arterial occlusive disease. Mean flow velocity was reliably determined by this method, but it could not be used as a determinant of arterial occlusive disease, because of a considerable overlapping between limbs with and without significant arterial lesions. A low value of mean flow velocity was not itself a reliable prognostic indicator of bypass failure. However, measurement of mean flow velocity was valuable in detecting functional abnormalities of the graft.     

Intraarterial digital subtraction angiography for evaluation of internal mammary artery graft in coronary bypass surgery

Digital subtraction angiography (DSA) was performed to evaluate graft patency in 60 patients who had undergone coronary artery bypass grafting with the internal mammary artery (IMA). Sixty IMA grafts with 62 distal anastomoses, and 84 saphenous vein grafts with 85 distal anastomoses were evaluated by intraarterial DSA with an image frequency of 4 frames/sec. A No. 4 Fr. angiography catheter was introduced percutaneously into the left brachial artery and contrast medium was injected both into the subclavian artery for opacification of the IMA grafts and into the ascending aorta for opacification of aortocoronary saphenous vein grafts. Bypass grafts were defined as patent when grafts were opacified through their entire course, including anastomotic sites. Fifty-nine IMA grafts with 61 distal anastomoses (98%) and 76 saphenous vein grafts with 77 distal anastomoses (91%) were patent. The overall patency rate for total grafts was 94%. In 4 patients, DSA showed a "string sign" in the IMA graft which was patent but narrowed at its distal segment. In 5 patients, large first intercostal branches were opacified. Intraarterial DSA with the retrograde brachial approach is not difficult, and is an excellent low risk method of evaluating the patency of IMA and saphenous vein grafts. DSA provided information about functional patency as well as anatomical patency of the IMA graft.     

Digital subtraction angiography of the pulmonary arteries

With current high-resolution equipment and proper case selection, intravenous digital subtraction angiography (IVDSA) can consistently demonstrate pulmonary emboli greater than 2.0 mm in size. IVDSA is less traumatic than conventional pulmonary angiography and is preferable for high-risk cases such as patients with pulmonary arterial hypertension. For successful IVDSA studies patients should be able to hold their breath for 10 to 20 seconds. IVDSA should not be used in patients who are extremely dyspneic, who cannot suppress a cough, or who have a low cardiac output. In these instances selective intraarterial DSA is preferable.     

Preoperative pulmonary evaluation

Factors related to risk of perioperative pulmonary complications include site of incision, obstructive lung disease, prolonged anesthesia time, smoking history with productive cough, and obesity. Hypercapnia is a consistent indicator of high risk. There is no difference between spinal and general anesthesia with regard to risk of pulmonary complications. In patients being evaluated for lung resection, high-risk indicators include predicted postoperative forced expiratory volume in one second of less than 1000 mL, hypercapnia, severe dyspnea on exertion, or advanced age when it is associated with advanced cardiopulmonary disease. Newer methods of assessing cardiopulmonary reserve may prove useful in identifying which patients with one or more of these risk factors are suitable operative candidates. Prevention of postoperative complications in chronic obstructive pulmonary disease patients should begin in the preoperative period with discontinuation of smoking at least eight weeks before surgery and vigorous pulmonary toilet in the 48 to 72 hours before surgery. Prophylactic lung expansion maneuvers can be effective in decreasing the incidence of postoperative atelectasis in high-risk patients undergoing high-risk operations.