Clinical evaluation of a new stationary high strip density antiscatter grid in comparison with a conventional moving grid: influence on image quality and patient radiation dose.
This study aimed to evaluate a new stationary 13/75 antiscatter grid in comparison with a moving 12/40 grid with regard to its influence on image quality and patient radiation dose. One hundred consecutive patients had plain films of the abdomen using a moving 12/40 grid and another 100 patients were examined with a stationary 13/75 grid (tube voltage 73 kV, film size 35 cm x 43 cm, film-screen system speed class 400). As an intraindividual comparison, radiographs of the abdomen with a film size of 18 cm x 43 cm were taken of 27 patients using both grid types for every patient. Patients' weight and dose-area product were recorded. Image quality was evaluated by a multireader study using standardized questionnaires and three- or five-level grading systems. Results showed that use of the 13/75 grid accords with the ALARA principle: measurement of the dose-area product demonstrated a dose saving of 24% for a film size of 35 cm x 43 cm and a saving of 34% for a film size of 18 cm x 43 cm without calling into question the diagnostic image quality. The mean scores of the 12/40 grid were lower for three out of six normal anatomic structures (P<0.05) among the 200 patients, indicating a loss of image quality with the 13/75 grid. Assessment of the intraindividual trial revealed reduced detectability of three out of four anatomical details when the 13/75 grid was employed. At the cost of a minor loss of image quality in comparison with the 12/40 grid, the new stationary grid provides a clear reduction of radiation dose under clinical circumstances.
Wamser
G R
GR
Department of Diagnostic Radiology and Neuroradiology, Klinikum Augsburg, Stenglinstrasse 2, 86156 Augsburg, Germany. radiol-klin.augsburg@gmx.de
Aichinger
H
H
Maier
W
W
Bohndorf
K
K
D000368:Aged; D004867:Equipment Design; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000000981:diagnostic imaging / Q000628:therapy; D008096:Lithotripsy; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011829:Radiation Dosage; D011859:Radiography / Q000295:instrumentation*; D011860:Radiography, Abdominal / Q000295:instrumentation*; D011874:Radiometry; D012542:Scattering, Radiation