Table 1.

Thames Valley Imaging Network

Hospital	Annual number of X-ray examinations	Annual number of CT examinations*	PACS introduced (filmless date)
A†	-	-	Jun 1, 2004
B‡			Feb 1, 2005
C‡	43609	36016	Mar 1, 2005
D‡			Mar 1, 2005
E	5071	-	Jun 1, 2005
F	1297	-	Aug 1, 2005
G	4007	-	Aug 1, 2005
H	2919	-	Sep 1, 2005
I	8501	5773	Oct 1, 2005
J	6924	3599	Dec 1, 2005

Abbreviations: PACS, picture archiving communication systems. X-ray counts are for chest and abdomen; computed tomography counts are for abdomen/pelvis, head, and chest, and were obtained using Ontario Health Insurance Plan (OHIP) data from the 2005/2006 fiscal year (April 1, 2005 to March 31, 2006).

*Computed tomography services were not provided by all Thames Valley hospitals during the observation period of this study.

†Diagnostic imaging exams were not billed to OHIP during the observation period of this study. Therefore, this institution was excluded.

‡These three hospital sites are part of the same corporation and are identified with a single institution number in the OHIP database. For the purposes of this study, hospitals B-D were treated as a single institution with a filmless date of March 1, 2005.