Neuro_MR_Brain: 18 M, lymphoma on intrathecal methotrexate, new neurologic findings.

CLINICAL HISTORY: 18-year-old male with lymphoma, received intrathecal methotrexate now with new neurologic findings.
Parenchyma: Multiple ill-defined areas of mild reduced diffusivity are noted within the subcortical and the white matter of the bilateral frontal lobes and right posterior temporal lobe. There is no associated mass effect, T2 signal abnormality, or abnormal enhancement. There is no evidence of hemorrhage.
Ventricles and extra-axial spaces: Appropriate for age.
Orbits: Normal.
Visualized paranasal sinuses: Clear.
Mastoid air cells: Clear.
Bones: Diffusely low marrow signal is seen, which may be related to patient's diagnosis of lymphoma or treatment related.
Time-of-flight MR angiography reveals no areas of flow-limiting stenosis, aneurysms, or other vascular abnormality. The dural venous sinuses are patent.
There is no perfusion abnormality associated with the areas of restricted diffusion.
Focal increased CBF is seen in association with a scalp lesion over the left parietal region, which be related to prior procedure, infectious or inflammatory process.
Additional comment: None.
1.  Multiple areas of mildly decreased diffusivity without abnormal T2 signal, enhancement, or hemorrhage within white matter as described above. This is a favored to be due to early methotrexate-induced leukoencephalopathy. Findings of this exam are not consistent with infarction, or CNS involvement of lymphoma. Septic emboli as mentioned in the request for exam could have possibly this appearance, although it is felt much less likely due to lack of enhancement or T2 signal abnormality.
2.  Normal perfusion.
3.  No evidence of flow-limiting stenosis or aneurysm.

(Methotrexate leukoencephalopathy)

Accession: CL27388574

Study description: MR BRAIN WandWO CONTRAST