Background: Intraoperative fluoroscopy is commonly
used in surgical procedures on upper extremities. We compared radiation
exposure from two possible positions of the mobile digital fluoroscopy
unit (c-arm): (1) the standard technique, with the x-ray
tube down (near the floor) and the image intensifier at the top
of the c-arm, and (2) the inverted position, in which the image
intensifier is used as a table and the x-ray tube is up.
Methods: A commercially available c-arm was used
to irradiate a phantom hand in one of three configurations. In the
first, the phantom hand was placed on an armboard equidistant from
the x-ray tube and the image intensifier with the beam directed
upward. In the second, the c-arm was inverted with the beam directed
downward and the image intensifier used as a table. The third configuration
was identical to the second except that a magnified image was used. Radiation
exposure was measured at four locations corresponding to the approximate
position of the surgeon’s head, chest, and groin and the
Results: The amount of radiation exposure to both
the surgeon and the patient was significantly less when the c-arm
was used in the inverted position (p < 0.0001). The dose
rate to the patient’s hand was reduced by 59%.
The radiation exposure to the surgeon’s head, body, and
groin with the inverted-c-arm technique was 67%, 45%,
and 15% of the measured doses with the x-ray-tube-down
configuration. When we used the magnification mode of the image
intensifier, with its correspondingly smaller field size, the doses
were further reduced to 46%, 32%, and 11% of
the standard-configuration values.
Conclusions: Use of the inverted-c-arm technique
with the image intensifier as an operating table can significantly reduce
radiation exposure to the surgeon and the patient during surgical
procedures on upper extremities.