Table 3.

Number of computed tomography (CT) examinations by age, body region and manufacturer reported using the expected phantom (for brain and skull CT: 16-cm phantom, for cervical spine, chest and abdomen: 32-cm phantom)

		Canon		GE		Philips		Siemens
		n	Percent using expected phantom	n	Percent using expected phantom	n	Percent using expected phantom	n	Percent using expected phantom
Brain	<1 y	395	100.%	2,143	99.8%	113	99.1%	3,567	99.9%
	1–4 y	1,005	100%	3,528	99.8%	409	100%	4,499	99.9%
	5–9 y	960	99.9%	3,523	99.6%	398	99.8%	4,159	99.9%
	10–14 y	1,479	99.8%	4,262	99.6%	811	99.8%	5,121	99.8%
	15–17 y	1,876	100%	4,577	99.7%	1,139	99.7%	4,716	99.8%
Skull	<1 y	9	88.9%	204	99.5%	7	100%	218	99.5%
	1–4 y	71	95.8%	743	99.1%	40	100%	819	99.5%
	5–9 y	139	96.4%	1,281	98.6%	47	95.7%	1,828	99.6%
	10–14 y	237	97.1%	1,276	98.4%	138	99.3%	2,254	99.7%
	15–17 y	349	94.0%	1,236	97.8%	231	99.6%	1,802	99.1%
Cervical spine	<1 y	11	100%	72	100%	1	100%	161	100%
	1–4 y	69	100%	499	100%	23	100%	899	100%
	5–9 y	101	100%	609	100%	31	100%	1,039	100%
	10–14 y	274	100%	705	100%	170	100%	1,525	100%
	15–17 y	535	100%	794	100%	293	100%	1,911	100%
Chest	<1 y	1	0%	284	74.7%	5	100%	707	99.7%
	1–4 y	14	85.7%	503	68.4%	1	100%	917	100%
	5–9 y	35	100%	596	80.0%	7	100%	900	99.9%
	10–14 y	69	100%	899	95.1%	10	100%	1,357	100%
	15–17 y	255	100%	1,248	99.1%	44	100%	1,607	100%
Abdomen	<1 y	13	92.3%	225	45.3%	6	100%	291	100%
	1–4 y	163	94.5%	863	47.5%	22	100%	1,229	99.9%
	5–9 y	693	98.3%	1,784	67.0%	144	100%	2,383	100%
	10–14 y	992	99.9%	2,787	91.9%	384	100%	3,752	100%
	15–17 y	1,443	100%	3,754	98.5%	744	100%	4,375	100%

y years