SAN FRANCISCO – Early routine MRI helped with the diagnosis of spontaneous intracerebral hemorrhage when added to CT imaging in a prospective, blinded study of 157 patients.
Previous analyses had suggested that adding MRI to brain CT imaging increased correct diagnoses of the cause of spontaneous intracerebral hemorrhage (ICH) by 26% and changed management in 15% of cases, but these percentages were based on the treating physician’s view, not independent neurologists, Dr. Christine A.C. Wijman noted.
The current study, called the Diagnostic Accuracy of MRI in Spontaneous Intracerebral Hemorrhage (DASH) study, supports those results. Two independent neuroradiologists found an absolute additive diagnostic benefit of 35% when MRI was added to CT imaging for diagnosing the etiology of ICH or intraventricular hemorrhage (IVH), Dr. Wijman said at the annual meeting of the Neurocritical Care Society.
Consecutive, prospectively enrolled patients underwent brain CT imaging, laboratory testing, and gadolinium-enhanced MRI or a magnetic resonance angiogram (MRA). If they met prespecified criteria, they underwent catheter angiography.
The cohort had a mean age of 63 years and 45% were female. Seventy-one percent had a history of hypertension, and 69% were on an antihypertensive drug at the time of admission.
Their intracranial hemorrhages had a mean initial volume of 25 cc, and associated IVH was present in 43%. The ICH location was lobar in 45% of cases and deep in 38%. The mean Glasgow Coma Score on admission was 14.
The study excluded patients with a known preexisting cause of ICH, an inability to undergo MRI, or a Glasgow Coma Scale score less than 6 on admission.
Initially, two independent neuroradiologists reviewed the admission CT and assigned a presumed cause of the ICH or IVH to 1 of 12 categories, rating the cause as “possible,” “likely,” or “highly probable.” They were blinded to all clinical data other than the patient’s age and sex. Next, two separate independent, blinded neuroradiologists used the first available MRI plus the CT results to do similar evaluations.
Their diagnoses were compared with determination of the etiology at 3 months by a stroke neurologist after review of the medical record including a 90-day clinic visit and follow-up MRI, if those were available.
The added information from the MRI changed the diagnosis of etiology in 24% of cases and improved diagnostic confidence in 11% of cases in which the identified cause did not change, for a combined “additive yield” of 35%, reported Dr. Wijman, director of critical care neurology at Stanford (Calif.) University.
The final diagnoses determined the cause of ICH or IVH to be longstanding or acute hypertension in 42% of cases, cerebral myeloid angioplasty in 15%, vascular malformation in 10%, infarct with hemorrhagic transformation in 8%, other diagnoses in 16%, and unknown causes in 8%. (Percentages do not equal 100% because of rounding.)
CT alone captured the final diagnosis in only 3% of patients. MRI or MRA alone captured the final diagnosis in 24%. Use of information from both imaging modalities captured the final diagnosis in 43%, and neither modality identified the etiology in 31%, Dr. Wijman said. (Percentages exceed 100% because of rounding.)
The MRI information changed the diagnosis of etiology in 10 (15%) of 66 cases of hypertension-related ICH and in 9 (38%) of 24 cases involving cerebral amyloid angiopathy or a variant of this disorder. The MRI information improved confidence in an unchanged diagnosis in eight of the hypertension-related cases (12%) and in five of the cerebral amyloid angiopathy cases (21%).
The additive yield of MRI was relatively highest for cases involving cerebral amyloid angiopathy, vascular malformations, hypertension, and other specific causes.
MRI or MRA proved helpful even in cases where it might be expected to be least useful. For example, the MRI/MRA results changed the diagnosis in 6 (13%) of 46 patients aged older than 45 years who had longstanding hypertension and a deep ICH, she added. It improved the diagnostic confidence in three of those cases (7%), for an overall diagnostic yield of 20%.
Disclosures: Dr. Wijman said the investigators have no pertinent conflicts of interest.