Reason: Assess for signs of methotrexate toxicity History: H/o relapsed ALL, recent MODS with ARF and possible methotrexate toxicity. Last intrathecal methotrexate 7/20/2015. MRI brain:There are new scattered foci of restricted diffusion in subcortical white matter of the right parietal lobe with a punctate focus in the right frontal lobe. There are additional periventricular foci of diffusion restriction in the left occipital and right parietal lobes. Extensive confluent T2 hyperintensity in the periventricular and subcortical white matter is new from the prior exam. The lateral, third and fourth ventricles are enlarged and sulci are prominent which is similar to the CT of 8/7/2015 but increased since the prior MRI, likely reflecting progressive volume loss. A small amount of susceptibility is associated with the right frontal centrum semiovale focus of diffusion restriction as well as a few foci in the right thalamus/posterior limb of the right internal capsule, likely reflecting areas of interval microhemorrhage.There is no midline shift or herniation. The major cerebral flow voids are intact. The orbits, skull and scalp soft tissues are grossly unremarkable. There is mucosal thickening of the sphenoid sinus, with aerated secretions the right. Opacification of the mastoid air cells bilaterally and fluid in the dependent pharynx is likely due to intubation.MRI cervical spine:Vertebral body heights and discs are intact. There is mild flexion which is likely positional, otherwise alignment is anatomic. No abnormal marrow signal. No abnormal signal within the visualized cord. No significant spinal or neuroforaminal stenosis. An NG tube and tracheostomy tube are noted fluid in the nasopharynx.
1.Multiple punctate scattered foci of diffusion restriction within the supratentorial white matter most conspicuous along the left occipital periventricular white matter, which are suspicious for acute infarcts. The distribution suggests an embolic source, possibly septic emboli provided patient's history. Of note, these lesions do not have a typical appearance for residual diffusion related changes related to methotrexate toxicity, although this possibility is not entirely excluded.2.Diffuse areas of confluent T2 hyperintensity within the subcortical and periventricular white matter are likely related to methotrexate toxicity, given time course of recent intrathecal methotrexate.3.Interval involvement of foci of punctate susceptibility along the right frontal centrum semiovale in the area of diffusion restriction as well as along the right thalamus/posterior limb of the right internal capsule, likely representing microhemorrhage.4.Normal MRI cervical spine.Findings discussed were discussed with Dr. Nubani by the resident on-call at 7:00 PM on 8/19/2015.