Merrill A. Wondrow

Effect of pulsed progressive fluoroscopy on reduction of radiation dose in the cardiac catheterization laboratory

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.

Does the use of new intracoronary interventional devices prolong radiation exposure in the cardiac catheterization laboratory

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.

Video X-ray progressive scanning: new technique for decreasing X-ray exposure without decreasing image quality during cardiac catheterization

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.

Optimization of wide-area ATM and local-Area Ethernet/FDDI network configurations for high-speed telemedicine communications employing NASA's ACTS

A high data rate terrestrial and satellite network was implemented to transfer medical images and data. This article describes the a optimization of the workstations and switching equipment incorporated into the network. Topics discussed in this article include tuning of the network software, the configuration of the Sun Microsystems workstations, the FORE Systems asynchronous transfer mode switches, as well as the throughput results of two telemedicine experiments undertaken by Mayos physician staff. The technical staff was successful in achieving the data throughput needed by the telemedicine software; particularly important was the proper determination of peak throughput and TCP window sizes to ensure optimum use of the resources available on the Sun Microsystems and Hewlett Packard workstations.

Cardiac catheterization laboratory imaging quality assurance program

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. Cathet Cardiovasc Intervent 2001;52:59–66.

Telemedicine Consultations in Congenital Heart Disease: Assessment of Advanced Technical Capabilities

OBJECTIVE To assess the value of adding remote pointer and dynamic display capabilities to a telemedicine system designed to provide consultative services for patients with congenital heart disease. MATERIAL AND METHODS Independent observations by the referring physician and the consulting physician provided the data for the assessment. Fifty-four teleconsultations involving 38 patients with 21 different congenital heart diseases were analyzed. The teleconsultations were based on previously obtained cineangiograms that were digitized and then transmitted by combined satellite and terrestrial-based technology. The observations, recorded by each physician at his workstation at the time of each teleconsultation, were summarized and analyzed statistically. RESULTS In 108 observations, the pointer was believed to be helpful in 72 (67%), and dynamic display was helpful in 96 (89%). CONCLUSION This study suggests that use of a pointer and dynamic display enhances teleconsultations for patients with congenital heart disease.

System for Transmitting Images

This invention relates to a system of transmitting images from one place to another by scanning an object field, transmitting the plurality of light and dark elements thus obtained 6 into a continuous series of impulses, and translating said impulses into light again and arranging them in an...

Archival systems for cineangiographic film replacement

Replacement of coronary cineangiographic film should become a reality within 2 to 3 years. This process has been accelerated by the American College of Cardiology, American College of Radiology, and the National Electrical Manufacturers Association Joint Committee, which has established a logical format (Digital Imaging and Communications in Medicine 3.0) and physical format (CD-R) as the standard media for the transport of cardiac catheterization images in place of cineangiographic film. Another integral part of the process is identification of the archival media. Standardization of this archival media has not been undertaken. The requirements for archival systems are as stringent as for the transport media. Several archival systems are described which meet these requirements, including capacity, read/write speed, access time, and backward/forward compatibility without the need for data compression. They are promising solutions to storage of large data sets.