HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Schueler, B. A. Search for Related Content PubMed PubMed Citation Articles by Schueler, B. A. Related Collections Physics and Basic Science

The AAPM/RSNA Physics Tutorial for Residents General Overview of Fluoroscopic Imaging¹

¹ From the Department of Diagnostic Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905. Received January 18, 2000; revision requested March 28 and received April 11; accepted April 14. Address correspondence to the author (e-mail: schueler.beth@mayo.edu).

View larger version (129K): [in a new window]   Figure 1.   Photograph shows an early (1933) fluoroscopic system in use before the development of image intensification. An actual fluoroscopic examination with this device would have occurred in a darkened room. (Reprinted, with permission, from the Mayo Foundation.)

View larger version (25K): [in a new window]   Figure 2.   Diagram shows the components of a fluoroscopic imaging chain.

View larger version (15K): [in a new window]   Figure 3a.   Effect of anode angle on heat capacity and effective focal spot size. Effective focal spot size is the focal spot area projected perpendicularly onto the image receptor. Diagram on the left (a) shows a large anode angle, which provides large radiation field coverage and a small effective focal spot size. However, the actual focal spot track on the anode is narrow, resulting in low heat capacity. The center diagram (b) illustrates a configuration with the same effective focal spot size and a small anode angle. This configuration results in greater heat capacity but small field coverage. To satisfy the requirements of both large field coverage and large heat capacity, the filament size must be increased, resulting in a larger effective focal spot size, as shown in c.

View larger version (6K): [in a new window]   Figure 3b.   Effect of anode angle on heat capacity and effective focal spot size. Effective focal spot size is the focal spot area projected perpendicularly onto the image receptor. Diagram on the left (a) shows a large anode angle, which provides large radiation field coverage and a small effective focal spot size. However, the actual focal spot track on the anode is narrow, resulting in low heat capacity. The center diagram (b) illustrates a configuration with the same effective focal spot size and a small anode angle. This configuration results in greater heat capacity but small field coverage. To satisfy the requirements of both large field coverage and large heat capacity, the filament size must be increased, resulting in a larger effective focal spot size, as shown in c.

View larger version (8K): [in a new window]   Figure 3c.   Effect of anode angle on heat capacity and effective focal spot size. Effective focal spot size is the focal spot area projected perpendicularly onto the image receptor. Diagram on the left (a) shows a large anode angle, which provides large radiation field coverage and a small effective focal spot size. However, the actual focal spot track on the anode is narrow, resulting in low heat capacity. The center diagram (b) illustrates a configuration with the same effective focal spot size and a small anode angle. This configuration results in greater heat capacity but small field coverage. To satisfy the requirements of both large field coverage and large heat capacity, the filament size must be increased, resulting in a larger effective focal spot size, as shown in c.

View larger version (102K): [in a new window]   Figure 4a.   Photographs show two types of equalization filters. These lead-rubber (a) and lead-acrylic (b) blades are mounted at the collimator with controls provided to adjust the blade location and rotation in order to conform to patient regions of low attenuation.

View larger version (133K): [in a new window]   Figure 4b.   Photographs show two types of equalization filters. These lead-rubber (a) and lead-acrylic (b) blades are mounted at the collimator with controls provided to adjust the blade location and rotation in order to conform to patient regions of low attenuation.

View larger version (19K): [in a new window]   Figure 5.   Diagram shows the components of an image intensifier. The paths of several incident x rays, converted to electrons at the input layer, are shown as dotted lines.

View larger version (43K): [in a new window]   Figure 6.   Diagram depicts an optical coupling system between an image intensifier (II), video camera, and optional image recording device (photospot camera or video camera).

View larger version (25K): [in a new window]   Figure 7.   Diagram illustrates a television system consisting of a video camera (left) and monitor (right). The horizontal raster scanning pattern of the electron beam across the video camera target is shown, along with the corresponding raster scan on the display monitor.

View larger version (116K): [in a new window]   Figure 8.   Under-table x-ray tube R/F system. Photograph shows an example of an R/F table that includes a spot film device and side-mounted video camera. (Courtesy of GE Medical Systems, Milwaukee, Wis.).

View larger version (109K): [in a new window]   Figure 9.   Over-table x-ray tube R/F system. Photograph shows a sample system that can be controlled from within the procedure room with the pedestal control panel (left) or from outside the room from the remote desk controls (right). (Courtesy of Philips Medical Systems North America, Shelton, Conn.)

View larger version (96K): [in a new window]   Figure 10.   Fixed C-arm positioner with ceiling mount. This example includes an incorporated ultrasound unit and patient monitoring system. (Courtesy of Philips Medical Systems North America, Shelton, Conn.)

View larger version (141K): [in a new window]   Figure 11.   Fixed Z-arm or parallelogram positioner. Photograph shows a 35-mm cine camera attached to the optical coupling accessory port between the image intensifier and video camera (Courtesy of TREX Medical Corporation, Littleton, Mass.)

View larger version (136K): [in a new window]   Figure 12.   Biplane positioners with frontal and lateral C-arms. This sample configuration includes a ceiling-suspended patient table. (Courtesy of Siemens Medical Systems, Iselin, NJ.)

View larger version (106K): [in a new window]   Figure 13.   Multipurpose fluoroscopy system. Photograph shows a tilt C-arm unit designed for multiple applications, including basic R/F examinations and interventional procedures. (Courtesy of GE Medical Systems, Milwaukee, Wis.)

View larger version (130K): [in a new window]   Figure 14.   Mobile C-arm unit. The control panel and monitor cart of this C-arm positioner can be moved independently. (Courtesy of Philips Medical Systems North America, Shelton, Conn.)

View larger version (104K): [in a new window]   Figure 15.   Mini C-arm unit. Photograph shows a compact mobile C-arm system with a small image intensifier. (Courtesy of OEC Medical Systems, Salt Lake City, Utah.)