MRI/MRA to assess acuity of brain infarcts

Patient: This is a 61 yo gentleman with h/o CVA, HTN, hyperlipidemia, seizure d/o, cocaine abuse, and medication noncompliance who presents with increasing right sided weakness and dysarthria of unknown duration less than one day, concerning for TIA versus CVA.

Treatment: Will obtain MRI/MRA to assess acuity of brain infarcts. Will obtain TTE to assess wall motion abnormalities in heart, given that patient has never had one in the past. Mural and valvular thrombi better visualized with TEE, but more

invasive test.

Is Preauth Required? For this treatment and condition, the prior authorization justifications might include: evaluation of a possible TIA or stroke, to assess for the presence of intracranial stenosis that may lead to the use of dual antiplatelet therapy, to evaluate for subclavian steal syndrome, to assess for the presence of mural and valvular thrombi, and to evaluate for the presence of an acute ischemia or infarct on brain imaging.

Will the claim be denied? The claim for MRI/MRA to assess acuity of brain infarcts and TTE to assess wall motion abnormalities in the heart would likely be approved. This is because the patient is presenting with signs and symptoms of a TIA or CVA, so vascular imaging is considered medically necessary to assess for intracranial stenosis. Additionally, the TTE would be medically necessary to assess for any mural or valvular thrombi.

When is the following treatment medically necessary for the condition specified? Vascular Imaging is considered medically necessary for acute (7 days or less) stroke or TIA in any of the following scenarios: evidence of acute ischemia or infarct on brain imaging, evaluation following acute TIA, signs or symptoms attributable to the anterior circulation when the presence of intracranial stenosis will lead to use of dual antiplatelet therapy, and signs or symptoms other than syncope attributable to the posterior circulation. The medical imaging studies recommended for these scenarios include CTA or MRA head, duplex arterial ultrasound, and CTA or MRA neck.