Radiology, Vol 197, 253-255, Copyright © 1995 by Radiological Society of North America
Positional variation in the Whitaker test
JH Ellis, RP Campo, MV Marx, RH Cohan, JF Platt, LP Sonda, GJ Faerber and DH Kim
Department of Radiology, University of Michigan Medical Center, Ann Arbor 48109-0030, USA.
PURPOSE: To describe positional variation in the outcome of the Whitaker
test. MATERIALS AND METHODS: The authors retrospectively reviewed the cases
of six patients in whom the pressure gradient during Whitaker testing
varied by at least 10 cm of water and changed from normal ( < or = 13 cm
of water) to abnormal ( > 13 cm of water) when patients were placed in
different positions. RESULTS: Four patients had obstruction only in
nonstandard positions. All had intermittent symptoms, and three had
ureteral kinks at fluoroscopy. Two patients with ileal conduits had
abnormal results in the standard position but normal results at
repositioning related to compression of the conduits (seen as conduit
distention at fluoroscopy). All six had undergone urinary tract surgery.
Gradient differences with positional change ranged from 10 to > 38 cm of
water. CONCLUSIONS: Whitaker testing in different positions may help
identify intermittent obstructions that might otherwise go undetected or
prevent inappropriate diagnosis of obstruction. Intermittent or unexplained
symptoms, tortuous ureters, malpositioned kidneys, or previous surgery are
indications for provocative positional testing.
