[Code of Federal Regulations] [Title 21, Volume 8] [Revised as of April 1, 2003] From the U.S. Government Printing Office via GPO Access [CITE: 21CFR892.1820] [Page 521] TITLE 21--FOOD AND DRUGS CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) PART 892--RADIOLOGY DEVICES--Table of Contents Subpart B--Diagnostic Devices Sec. 892.1820 Pneumoencephalographic chair. (a) Identification. A pneumoencephalographic chair is a chair intended to support and position a patient during pneumoencephalography (x-ray imaging of the brain). (b) Classification. Class II.