Conventional MR as an important paraclinical tool for diagnosing multiple sclerosis (MS) and monitoring therapeutic trials offers by far the most sensitive technique for detecting MS lesions.

Its purpose is especially important in ruling in or ruling out a diagnosis of MS. The ability to detect lesions depends on the pulse sequence, imaging parameters and the field strength.

There is a special MR protocol which has to be performed with application of gadolinium contrast media in order to increase the sensitivity and specificity of conventional MR examination since the lesion number and location are included in the diagnostic criteria of MS.

Although MS lesion plaques can be found throughout the brain, spinal medulla, orbit and cranial nerves, they usually have specific features which help to distinguish MS from other demyelinating, cerebrovascular diseases or any other diseases that affect white matter of the brain. Conventional MR is also helpful in distinguishing MS variants and subtypes.

Although conventional MR is a powerful paraclinical technique to depict MS lesions, one should bear in mind that there are cases of MR-negative MS. Therefore, to obtain the diagnosis of MS it is necessary to synthesize the results of clinical exams, laboratory tests and all the paraclinical exams as well as their changes in time.