(October 31, 2007 - Insidermedicine) Incidental brain findings on MRI, including brain infarcts, cerebral aneurysms, and benign primary tumours, are being detected more frequently in asymptomatic patients due to improved technology and more frequent testing, say experts in a report published in the New England Journal of Medicine.

Clinical guidelines for the use of imaging include:

.    In stroke, MRI can detect acute and chronic ICH (intracerebral hemorrage). Although the detection of SAH (subarachnoid hemorrage) is possible with MRI, currently CT scan is the diagnostic procedure of choice.

.   MRI has a higher sensitivity than conventional CT for the documentation of infarction within the first hours of stroke onset, lesions in the posterior fossa, identification of small lesions, and documentation of vessel occlusion and brain edema .

.   MRA (magnetic resonance angiography) is the recommended technique for screening cerebral aneurysms in individuals with a history of aneurysms or SAH in a first-degree relative .

In the present study, researchers aimed to determine the approximate number of brain abnormalities detected in asymptomatic patients undergoing MRI. They reviewed the incidental findings among 2000 people 45 years of age and older from the general population who had no signs or symptoms of having brain abnormalities.

Asymptomatic brain infarcts were detected in 7% of the people tested, 2% had aneurysms, and 1.6% had primary benign tumours. The likelihood of having brain infarcts and brain tumours, they found, increased with age.

Incidental findings on brain MRI are common and information regarding the prognosis of these abnormalities is needed to determine what steps should be taken to manage these patients.

We spoke to Dr. Meike Vernooij from Erasmus University Medical Center in the Netherlands about the implications of this study for doctors.

For Insidermedicine in Depth, I'm Dr. Susan Sharma.