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Continuous developments in digital imaging technology have contributed to the vital role held today by digital X-ray imaging in the cardiac catheterization laboratory. Foremost among these developments is the replacement of cine film with digital data equivalents as the procedure record. Other improvements include software innovations and processing algorithms, along with new types of hardware capable of delivering required functionality more rapidly. A significant recent development is that of the flat-panel X-ray detector as a replacement for the image intensifier, which has served the needs of the cardiac catheterization laboratory for nearly 5 decades. Clinical users must evaluate the respective technologies and determine whether one or the other meets the needs of their own laboratories. In this review, the two competing detector technologies are reviewed and a summary of general advantages and disadvantages of each is provided. A qualitative description is provided of parameters that can be used to assess quantitatively the performance of detectors and imaging systems. Using such objective measurements, together with standard techniques for evaluating imaging systems, angiographers and managers can better arrive at informed decisions for their own situation.

With the recent approval of the National Electrical Manufacturers Association (NEMA) standard for "Characteristics of and Test Procedures for a Phantom to Benchmark Cardiac Fluoroscopic and Photographic Performance," comprehensive cardiac image assurance control programs are now possible. This standard was developed by a joint NEMA/Society for Cardiac Angiography and Interventions (SCA&I) working group of imaging manufacturers and cardiology society professionals over the past 4 years. This article details a cardiac catheterization laboratory image quality assurance and control program that includes the new standard along with current regulatory requirements for cardiac imaging. Because of the recent proliferation of digital imaging equipment, quality assurance for cardiac imaging fluoroscopy and digital imaging are critical. Included are the previous works recommended by the American College of Cardiology (ACC) and American Heart Association (AHA), Society for Cardiac Angiographers and Interventions (SCA&I), and authors of previous image quality subjects.

Objectives: The aim of this study was to compare the duration of radiation exposure associated with new percutaneous coronary interventional devices with that associated with conventional balloon angioplasty., Background: Radiation exposure levels have been documented to be higher with coronary balloon angioplasty than with routine diagnostic coronary angiography. However, the effect of new interventional devices on radiation exposure has not been studied., Methods: Fluoroscopic and cineangiographic data from the Mayo Clinic cardiac catheterization laboratory data base of patients having single-segment coronary intervention during a recent 46-month period were retrospectively analyzed. Of 897 patients studied, 646 underwent balloon angioplasty, 138 directional coronary atherectomy (42 with adjunctive balloon angioplasty), 76 excimer laser angioplasty (50 with adjunctive balloon angioplasty) and 37 placement of an intracoronary stent (16 emergencies)., Results: Duration of fluoroscopy during balloon angioplasty was 24 +/- 18 min, which was longer than with directional atherectomy (18 +/- 8 min; p = 0.001). Fluoroscopy time was 25 +/- 17 min with laser angioplasty and 29 +/- 15 min with elective stent placement (neither time was significantly different from that with balloon angioplasty). When atherectomy or laser angioplasty was performed with adjunctive balloon angioplasty or if emergency intracoronary stent placement was performed, the duration of fluoroscopy was significantly prolonged compared with balloon angioplasty alone., Conclusions: Fluoroscopy duration is not prolonged with the use of new interventional coronary devices compared with conventional angioplasty unless adjunctive balloon angioplasty is used or emergency stent placement is required.

The increased application of therapeutic interventional cardiology procedures is associated with increased radiation exposure to physicians, patients and technical personnel. New advances in imaging techniques have the potential for reducing radiation exposure. A progressive scanning video system with a standard vascular phantom has been shown to decrease entrance radiation exposure. The effect of this system on reducing actual radiation exposure to physicians and technicians was assessed from 1984 through 1987. During this time, progressive fluoroscopy was added sequentially to all four adult catheterization laboratories; no changes in shielding procedures were made. During this time, the case load per physician increased by 63% and the number of percutaneous transluminal coronary angioplasty procedures (a high radiation procedure) increased by 244%. Despite these increases in both case load and higher radiation procedures, the average radiation exposure per physician declined by 37%. During the same time, the radiation exposure for technicians decreased by 35%. Pulsed progressive fluoroscopy is effective for reducing radiation exposure to catheterization laboratory physicians and technical staff.

A newly developed video x-ray progressive scanning system improves image quality, decreases radiation exposure, and can be added to any pulsed fluoroscopic x-ray system using a video display without major system modifications. With use of progressive video scanning, the radiation entrance exposure rate measured with a vascular phantom was decreased by 32 to 53% in comparison with a conventional fluoroscopic x-ray system. In addition to this substantial decrease in radiation exposure, the quality of the image was improved because of less motion blur and artifact. Progressive video scanning has the potential for widespread application to all pulsed fluoroscopic x-ray systems. Use of this technique should make cardiac catheterization procedures and all other fluoroscopic procedures safer for the patient and the involved medical and paramedical staff.

This study evaluated a new high line rate (1,023-line) high band-width (10 MHz) system, compared it to our high-definition, 525-line video system, and compared both video systems to 35-mm cine angiography in 117 patients undergoing clinically indicated coronary angiography. The subjective image quality of the 1,023-line video system was not significantly better than that of the 525-line system. High line rate, high band-width systems may have theoretical advantages, but the increased noise level under clinical angiographic conditions reduces their diagnostic quality. Comparison between video (all modes) and cine images resulted in cine being rated as the best modality, but the differences were slight. Radiation levels required for video imaging, however, were significantly less than those required for cine recording. Current clinical and computer interactive uses of video systems in the cardiac laboratory are described. The eventual role and potential replacement of cine recording by video tape systems will depend on continued developments in video recording techniques.

The widespread growth of interventional angiographic procedures has expanded the use of X-ray video systems. Reduced radiation exposure to the patient and staff has been recently reported by implementing a new pulsed progressive scanning video system. We have shown that this system, which enables the pulsing of the X-ray generator at 30 pulses per second, results in a 50% reduction in radiation exposure. The technical parameters and implementation of a progressive scanning video system are discussed. Image quality, temporal and spatial resolution, and signal-to-noise ratio (SNR) were assessed using conventional interlaced and progressive video scanning. These comparisons documented improved resolution, no degradation of ejection fraction measurements, improved clinical images, and a 1.0-dB improvement in the SNR with the progressive scanning. Progressive scanning video systems reduce radiation exposure and provide an objective improvement in image quality over conventional scanning video systems.