[A design of the measuring chart for magnifying-power compensation in brain angiography].
OBJECTIVE
When brain angiography was performed, we devised the calculation theory for rectifying magnifying power, and produced the auxiliary tool.


METHODS
We produced the frame with a size of 300 x 300 x 15 mm from the thin board made from carbon. The frame is around arranged for every 1 cm in Pb-ball of the diameter of 1 mm. We named this the measuring-chart. The measuring-chart has been arranged so that head may be surrounded. A photograph of a measuring-chart and head was taken simultaneously. The projected mark used for computing the magnifying power of a brain aneurysm. Magnifying power was used in order to measure the size of an aneurysm.


RESULTS
In the basic experiment using the stainless-steel ball whose size is known, the standard error was -2.29% +/- 5.61%. A measurement value and true value showed high correlation (R(2) = 0.9986).


CONCLUSIONS
The measuring-chart did not need a proofreading factor peculiar to equipment. This method had high accuracy. This method has high flexibility. It suggested that this method was useful on clinical use.
Matsumoto
Kazuma
K
Department of Radiology, Hospital of Hyogo College of Medicine.
Sakamoto
Kiyoshi
K
Umehara
Takayoshi
T
Maeda
Katsuhiko
K
Itoh
Hiroshi
H
D015901:Angiography, Digital Subtraction / Q000295:instrumentation; D002138:Calibration; D002533:Cerebral Angiography / Q000295:instrumentation*; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000473:pathology; D019047:Phantoms, Imaging; D011858:Radiographic Magnification / Q000295:instrumentation*; D015641:Radiography, Interventional / Q000295:instrumentation; D012680:Sensitivity and Specificity