Film-screen Angiography Research Articles

Acute Pulmonary Thromboembolism: Comparison of the Diagnostic Capabilities of Conventional Film-Screen and Digital Angiography

To compare digital to conventional film-screen pulmonary angiography for the diagnosis of acute pulmonary embolism (PE) in a clinical population. Retrospective review of patient data, ventilation/perfusion (V/Q) lung scintigraphy reports, and pulmonary angiographic reports. University hospital, division of interventional radiology. Patient data from 307 film-screen and 266 digital angiograms were analyzed for demographics, V/Q lung scintigraphy findings, and pulmonary artery pressures to define patient populations. The interpretations of film-screen pulmonary angiography were then compared with digital angiography interpretations for the entire group of interventional radiologists as well as the two interventionists who practiced throughout the study interval to determine any difference in rates of diagnosis of acute PE between the two techniques. There was no significant difference between the patient populations studied by film-screen or digital techniques for the data reviewed. Digital angiography utilized significantly more contrast material (digital, 173 mL; film-screen, 145 mL; p < 0.01) and a greater number of angiographic views (digital, 3.6 views per patient; film-screen, 3.4 views per patient; p = 0.04) when compared with film-screen angiography. There was no difference between the two techniques in the rates of diagnosis of acute PE, for individual radiologists or overall. Digital and film-screen pulmonary angiography possess equivalent diagnostic capabilities for acute PE as used in a clinical setting.

Digital Subtraction versus Film-Screen Angiography for Detecting Acute Pulmonary Emboli: Evaluation in a Porcine Model

To compare the diagnostic performance of digital subtraction angiography (DSA) to that of film-screen angiography (FSA) for detecting acute pulmonary embolism (PE) in a porcine model. DSA and FSA were performed in 13 pigs before and after central venous administration of autologous emboli. Results were compared to findings at necropsy with use of ex vivo pulmonary angiography to guide pathologic sectioning. The sensitivity and predictive value of a positive case for detecting each embolus were computed for each pulmonary artery branch order and compared with use of 95% confidence intervals. Interobserver variability among three readers for individual PE detection was calculated. Pathologic examination of the lungs revealed 100 total PEs (location by vessel order: 1st = 1, 2nd = 0, 3rd = 15, 4th = 32, > 5th = 52). On average, FSA review identified 72 (72%) emboli and DSA review, 65 (65%). There was no significant difference in sensitivity or predictive value of a positive case between DSA and FSA for detecting emboli (P > .05). There was similar agreement among readers for individual PE detection with DSA (mean, 84%) and FSA (mean, 80%). The diagnostic performance of DSA is equivalent to that of FSA for detecting emboli in porcine PA branches. Interobserver agreement for individual PE detection is similar for both imaging techniques.

Non-selective digital subtraction angiography in comparison with selective conventional angiography in the diagnosis of carotid artery disease

In the recent past, non-selective arterial digital subtraction angiography (NSDSA) seemed a less invasive alternative to conventional filmscreen angiography (CFA) in the diagnosis of carotid artery disease. NSDSA obviated the need for selective catheterization with its associated risks but yet took advantage of the DSA method. However, this technique has not found general application although there are no reports that formally assess the (dis)advantages of NSDSA. The aim of our study was to compare the reliability of NSDSA with CFA in evaluation of carotid bifurcations in patients with transient ischemic attacks or partial stroke by reviewing prospectively collected data. Over a 2-year period, 40 patients (upper age limit 65 years) underwent both NSDSA and CFA. Bilateral NSDSA was performed in all 40 patients (80 bifurcations). Bilateral CFA was performed in 27 patients whereas unilateral CFA was carried out in 13 patients (67 bifurcations). Inter- and intra-observer variability for the degree of stenosis was determined by calculation of kappa-values for a 4-point and a 2-point scale. The proportion of interpretable studies was significantly lower in NSDSA. The inter- and intra-observer agreement was on average better in CFA examinations, though the difference was only statistically significant for the inter-observer agreement. The results of our study indicate that images obtained with NSDSA give less reliable information about carotid artery disease than images obtained with CFA. This is in accordance with the fact that NSDSA now seems an abandoned technique.

Stepped digital angiography with dynamic subtraction: a new diagnostic approach to peripheral angiography

On the basis of our first experiences, a purchasable angiography system for peripheral angiography with dynamic subtraction and stepping (DPSA) has been developed. This study reports on the optimization of this technique and the first clinical results in comparison with conventional screen-film angiography and digital subtraction angiography (DSA) in single steps. For each method, 25 angiograms were interpreted to compare the image quality, the radiation exposure, the contrast medium and the film consumption as well as the examination time. Image quality proved to be comparable in DPSA and DSA in single steps. Both techniques showed better results than conventional angiography, especially in the region of the knee and lower leg. Using DPSA radiation exposure dropped by a factor of 2 compared with conventional angiography and by a factor of 6 compared with DSA in single steps. Consumption of contrast medium can also be reduced in comparison with the other two methods. Film consumption is incomparably higher in conventional screen-film angiography. With DPSA the examination time can be reduced by half on average compared with the other two methods. DPSA may come to be the standard in peripheral angiography.

Comparison of the efficacy of digital subtraction and film-screen angiography of the lower limb: prospective study in 50 patients.

We prospectively compared current digital subtraction angiography (DSA) with conventional film-screen angiography (FSA) of the lower limb for evaluation of areas of arterial stenosis and degree of arterial visualization. Fifty patients had both DSA and FSA of a single lower limb. Specific anatomic sites (examiner-selected sites) throughout the lower limb were marked on each film by an experienced angiographer (examiner). These sites consisted of the common femoral, superficial femoral, popliteal, anterior tibial, posterior tibial, peroneal, and dorsalis pedis arteries and bypass grafts, when present. The films were then reviewed blindly by two different experienced angiographers (observers). All sites were graded for the degree of arterial narrowing based on a standard scale (grade 1 = normal, grade 5 = occluded) that also included grading for nonvisualization (grade 6). Each observer also selected the most stenotic site in each anatomic area (observer-selected sites). The data were analyzed for the entire lower limb and at specific anatomic sites. DSA sites were judged to be slightly more narrowed (p less than .05) in the superficial femoral artery by both observers and in the common femoral artery, bypass graft, and overall by a single observer. No other significant differences were found in grade of stenosis or vessel visualization for examiner-selected sites. For observer-selected sites, observers agreed on the location of the most stenotic site 76% of the time for FSA and 69% of the time for DSA. No significant difference was found in grade of stenosis or vessel visualization for either observer for the entire lower limb or at specific anatomic sites. These findings were present when all sites chosen were considered and when there was agreement between sites chosen on FSA and DSA for each observer. In conclusion, optimal-quality FSA and DSA produced virtually equivalent results for angiography of the lower limb for both grade of stenosis/occlusion and vessel visualization.

Comparison of Nonsubtracted Digital Angiography and Conventional Screen-Film Angiography for the Evaluation of Patients with Peripheral Vascular Disease

Recently, x-ray equipment manufacturers have produced systems capable of generating nonsubtracted digital angiograms (NSDA) of the arteries of the lower extremities with a high-resolution 1,024 x 1,024 matrix. One such system was compared with conventional screen-film angiography (CSFA) for the evaluation of peripheral vascular disease. Both NSDA and CSFA were performed prospectively in an identical fashion on 47 patients. The images were evaluated, and diagnostic adequacy (ie, information sufficient to direct subsequent therapy) and a variety of image quality attributes--vessel opacification, correct timing, complete anatomic coverage, and ease of reading--were compared. CSFA and NSDA provided similar diagnostic information. NSDA was judged superior to CSFA with regard to timing (P less than .001). CSFA was judged superior with regard to anatomic coverage (P less than .001) and ease of reading (P less than .01). NSDA is a promising method for evaluating patients with peripheral vascular disease. Further work is needed to provide more complete anatomic coverage and to improve the quality of the hard-copy images.

Intraarterial digital subtraction angiography in detection of hepatocellular carcinoma

To evaluate the usefulness of intraarterial digital subtraction angiography (IADSA) in hepatocellular carcinoma, IADSA was prospectively performed, combined with conventional film-screen angiography, in 40 patients in whom the tumor was histologically proven or highly suspected. Of the 16 main tumors less than 2 cm, IADSA detected 7 that were missed by film-screen angiography; 6 of these were less than 1 cm in size. With other diagnostic modalities including ultrasound, routine CT study, and CT after intraarterial Lipiodol injection, the detection rate of these tumors was low. IADSA's contribution is important in the detection of small hepatocellular carcinomas.

Use of digital subtraction angiography for evaluation of vascular access for hemodialysis.

We used digital subtraction angiography (DSA) with conventional methods of contrast injection to evaluate 13 failing vascular accesses in 12 patients undergoing hemodialysis. DSA results were confirmed in all cases by surgical findings and/or clinical follow-up. The DSA technique is extremely flexible and rapid and requires the injection of only small amounts of dilute contrast with much less patient discomfort. DSA is an excellent alternative to film screen angiography for the evaluation of vascular access complications.

Portal hypertension workup by DSA.

To provide information for preoperative planning, combined, selective intravenous (IV) and intraarterial (IA) digital subtraction angiography (DSA) studies were performed on 42 portal hypertension patients scheduled for portal systemic shunt procedures. Selective IV-DSA was performed to demonstrate the hepatic venous system, left renal vein, and inferior vena cava. Portal venous anatomy, direction of flow, and portal systemic collaterals were evaluated by selective IA-DSA. In addition, selective IA-DSA was performed postoperatively on 8 patients to assess shunt patency. Technically adequate DSA studies, suitable for surgical planning or postoperative assessment, were obtained in all of the 50 patients examined. Patient or internal organ motion was not a limiting factor in any study. Such use of DSA represents an efficacious, safe, and cost-effective alternative to conventional film-screen angiography for the evaluation of patients with portal hypertension.

Digital subtraction angiography (DSA): a neurosurgical perspective.

The purpose of this article is to review the contribution of DSA to neurosurgical practice and to outline its advantages and limitations compared to conventional film-screen angiography. DSA is a technique whereby electronic subtraction allows the near instantaneous demonstration of vascular anatomy essentially free of bony detail. Because DSA possesses a high degree of contrast sensitivity, arterial images can be produced after an intravenous injection of contrast medium as well as by selective arterial catheterisation.

Work in progress. Intra-arterial digital subtraction angiography: evaluation in 150 patients.

As part of an ongoing study comparing digital subtraction angiography (DSA) with conventional film-screen angiography, 150 patients were examined with arterial contrast material injections and digital filming techniques alone or combined with conventional angiography. Of 247 injections, the DSA study was good or excellent in 236, approaching the quality of conventional angiography for visualization of vessels greater than 1 mm in size. Advantages included improved vascular detail in selected areas such as the skull base, visualization of minimal contrast concentration in diseased vessels or postoperatively, and imaging of vessels distal to stenoses without the hazards of selective catheterization. DSA permitted rapid positioning under fluoroscopic control, instantaneous viewing of subtracted images, and reduced technologist time and film costs. Contrast material volume was reduced by 40 to 60%, allowing multiple studies in one sitting and study of patients with renal compromise.

Digital Subtraction Angiography in the Evaluation of Cerebrovascular Disease

Intravenous DSA provides a safe, accurate, and cost-effective means of examining the extracranial and intracranial vasculature on an inpatient or outpatient basis. Intra-arterial DSA provides better spatial resolution than IV-DSA and has advantages over conventional film-screen angiography. The authors demonstrate the applications and limitations of this revolutionary diagnostic technique.