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A Nonplanimetric Technique for Measuring Fluid Volumes Using MR Imaging: Phantom results

  • John A. Malko
  • Eric C. McClees
  • Ira F. Braun
  • Patricia C. Davis
  • James C. HoffmanJr.

Abstract

A nonplanimetric algorithm for calculating the volume of homogeneous fluids, using data from a single slice MRI scan, is discussed. The algorithm uses the fact that the total MR signal from a homogeneous fluid placed inside an MR scanner is directly proportional to the volume of the fluid. A simple ratio of fluid volumes and signal strengths thus allows the determination of an unknown fluid volume from a known fluid volume and the measured signals from the known and unknown volumes. Signal strengths are obtained from a single image of the known and unknown volumes, by a simple summation of pixel intensities in the image. The volume algorithm was tested on a 0.5 T clinical imager using fluid-filled volume phantoms (85–500 ml) that ranged in complexity from simple bulk volumes (flasks) to a mock-brain phantom composed of two fluid-filled bottles (to represent ventricles) embedded in a tangle of small-diameter fluid-filled tubes (to represent sulci). The known volume was a 5 ml syringe filled with the same fluid as contained in the phantoms. Volumes were calculated using various single-slice spin-echo pulse sequences and were in all cases found to be within 3% of the known volumes. The phantom results imply that intracranial CSF volumes might be determined by comparing signals derived from intracranial CSF with those from known volumes of CSF. Such a procedure would require the use of a pulse sequence that returns a signal from the CSF only, such as a very long TE spin-echo sequence. Among the questions still to be addressed are the possible differences between intracranial and in vitro CSF and the effects of CSF flow. (AJNR 8: 267–270, 1987)

Key words

MRI Volumes CSF 

Copyright information

© Springer-Verlag Berlin Heidelberg 1990

Authors and Affiliations

  • John A. Malko
    • 1
  • Eric C. McClees
    • 1
  • Ira F. Braun
    • 1
  • Patricia C. Davis
    • 1
  • James C. HoffmanJr.
    • 1
  1. 1.Department of RadiologyEmory University School of MedicineAtlantaUSA

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