MRI abnormalities:
(1) either (a) >= 1 gadolinium-enhancing lesion OR (b) >= 9 T2-hyperintense lesions
(2) >= 1 infratentorial lesion
(3) >= 1 juxtacortical lesion
(4) >= 3 periventricular lesions
where:
• According to McDonald et al, 1 spinal cord lesion can be substituted for one brain lesion.
number of abnormalities present =
= SUM(number of abnormalities identified)
Interpretation:
• minimum number of abnormalities: 0
• maximum number of abnormalities: 4
• The more abnormalities identified, the greater the risk of developing clinically definite multiple sclerosis.
|
Number of Abnormalities
|
Observed Risk of Clinically Definite MS (Barkhof et al)
|
Observed Risk of Clinically Definite MS (Tintore et al)
|
|
0
|
16%
|
7.7%
|
|
1
|
11%
|
25%
|
|
2
|
54%
|
28%
|
|
3
|
75%
|
50%
|
|
4
|
87%
|
58%
|
after Barkhof Table 4, page 2066; Tintore Table 4, page 704.
|
Number of Abnormalities
|
Sensitivity
|
Specificity
|
Accuracy
|
|
1
|
91%
|
50%
|
62%
|
|
2
|
82%
|
62%
|
68%
|
|
3
|
73%
|
73%
|
73%
|
|
4
|
45%
|
85%
|
72%
|
after Tintore Table 3, page 704
