Accuracy of magnetic resonance imaging for the diagnosis of multiple sclerosis: systematic review

Abstract

Objective: To determine the accuracy of magnetic resonance imaging criteria for the early diagnosis of multiple sclerosis in patients with suspected disease.

Design: Systematic review.

Data sources: 12 electronic databases, citation searches, and reference lists of included studies. Review methods Studies on accuracy of diagnosis that compared magnetic resonance imaging, or diagnostic criteria incorporating such imaging, to a reference standard for the diagnosis of multiple sclerosis.

Results: 29 studies (18 cohort studies, 11 other designs) were included. On average, studies of other designs (mainly diagnostic case-control studies) produced higher estimated diagnostic odds ratios than did cohort studies. Among 15 studies of higher methodological quality (cohort design, clinical follow-up as reference standard), those with longer follow-up produced higher estimates of specificity and lower estimates of sensitivity. Only two such studies followed patients for more than 10 years. Even in the presence of many lesions (> 10 or > 8), magnetic resonance imaging could not accurately rule multiple sclerosis in (likelihood ratio of a positive test result 3.0 and 2.0, respectively). Similarly, the absence of lesions was of limited utility in ruling out a diagnosis of multiple sclerosis (likelihood ratio of a negative test result 0.1 and 0.5).

Conclusions: Many evaluations of the accuracy of magnetic resonance imaging for the early detection of multiple sclerosis have produced inflated estimates of test performance owing to methodological weaknesses. Use of magnetic resonance imaging to confirm multiple sclerosis on the basis of a single attack of neurological dysfunction may lead to over-diagnosis and over-treatment.

Table 2

Study details and results of case-control studies and studies of other designs

Table 2

Study details and results of case-control studies and studies of other designs

Fig 1

Flow of studies through review process

Fig 2

Results of quality assessment for appropriate patient spectrum studies

Fig 3

Receiver operating characteristic plots for cohort studies and for studies of other designs

Fig 4

Receiver operating characteristic plots for studies included in hierarchical summary receiver operating characteristic analysis. Numbers are duration of follow-up in years

Fig 5

Receiver operating characteristic plots (95% confidence intervals) for Barkhof, Fazekas, Paty, and McDonald 2001 criteria. In Barkhof plot, red is study that proposed Barkhof criteria. In McDonald 2001 plot, red indicates studies where McDonald 2001 criterion was applied after three months rather than 12 months

Fig 6

Sensitivity plotted against specificity (95% confidence intervals) for different thresholds (number of lesions shown next to plots) reported in English and US studies