Cluster 667: spine mri lumbar vertebral patients brain osteoporosis prior hip surgery 
Cluster 1254: cns involvement nervous central puncture lumbar active known patients disease 
Cluster 2043: cerebrospinal fluid csf cns nervous central involvement cytology leptomeningeal lymphoma 
Cluster 2357: involvement nervous cns central known lymphoma patients intrathecal refractory aml 
Cluster 2480: evidence leukemic cns active involvement definitively meningeal cerebral disease nervous