Magnetic resonance imaging of the knee in Norway 2002–2004 (national survey): rapid increase, older patients, large geographic differences

Table 3 MRI-scanners in Norway, by geographic region

	Mean* (rate = mean per million persons in region)			Change in rate# from 2002 to 2004, %
	2002	2003	2004
North	7.5 (16.2)	8.0 (17.3)	8.5 (18.4)	+ 13
Central	8.5 (13.3)	13.5 (21.1)	16.0 (24.9)	+ 87
West	7.0 (7.6)	9.5 (10.2)	13.0 (13.8)	+ 83
South/East	43.5 (17.4)	52.5 (20.9)	58.5 (23.1)	+ 33
Norway	66.5 (14.7)	83.5 (18.3)	96.0 (21.0)	+ 43

MRI = magnetic resonance imaging.
* Mean number of scanners each year is mean of numbers 1. January same and next year.
# Mantel-Haenszel chi-square test for linear trend in change: p = 0.03 for Norway, p = 0.81 for region North and p = 0.16–0.19 for the other regions.

ISSN: 1472-6963