Dose reduction in gastrointestinal and genitourinary fluoroscopy: use of grid-controlled pulsed fluoroscopy.
OBJECTIVE
We evaluated the diagnostic accuracy of a grid-controlled fluoroscopy unit compared with a conventional continuous fluoroscopy unit for a variety of abdominal and pelvic fluoroscopic examinations.


METHODS
Seventy patients (29 men and 41 women; age range, 24-78 years) were enrolled in one of seven abdominal and pelvic fluoroscopic examinations, including upper gastrointestinal series (n = 20), barium enema (n = 10), voiding cystourethrogram (n = 10), percutaneous abdominal catheter tube injection (n = 10), hysterosalpingogram (n = 10), and percutaneous needle insertion and catheter placement (nephrostomy, percutaneous biliary drainage) (n = 10). Each patient underwent at least 10 sec of continuous fluoroscopy that was randomly and blindly compared with 10-sec periods of pulsed fluoroscopy at 15, 7.5, and 3.75 frames per second. A radiologist outside the examination room, unaware of the frame rate per second, evaluated the procedure in real time on a television monitor. The radiologist assessed image quality and diagnostic acceptability using a scoring system. Statistical analysis was performed using the paired Student's t test.


RESULTS
For all procedures at all frame rates, we found no statistically significant superiority of one frame rate over another. For most procedures, the slower frame rates were considered equivalent to continuous fluoroscopy when the images were assessed for image quality and diagnostic confidence.


CONCLUSIONS
Our findings suggest that most abdominal and pelvic fluoroscopic procedures can be performed at substantially lower frame rates than those used for continuous fluoroscopy; adopting this procedure may lead to substantial dose savings for the patient and the fluoroscopy operator.
Boland
G W
GW
All authors: Division of Abdominal Imaging and Interventional Radiology, Massachusetts General Hospital, White 270, 55 Fruit St., Boston, MA 02114, USA.
Murphy
B
B
Arellano
R
R
Niklason
L
L
Mueller
P R
PR
D000328:Adult; D000368:Aged; D001466:Barium Sulfate / Q000008:administration & dosage; D002404:Catheterization / Q000295:instrumentation; D003287:Contrast Media / Q000008:administration & dosage; D004064:Digestive System / Q000000981:diagnostic imaging*; D004733:Enema; D005260:Female; D005471:Fluoroscopy / Q000379:methods*; D006801:Humans; D007047:Hysterosalpingography; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement; D015641:Radiography, Interventional; D016037:Single-Blind Method; D014521:Urethra / Q000000981:diagnostic imaging; D001743:Urinary Bladder / Q000000981:diagnostic imaging; D014567:Urography
D003287:Contrast Media; D001466:Barium Sulfate