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X‐ray imaging technique for in vitro tissue composition measurements using saline/iodine displacement: Experimental verification
Author(s) -
Moreau M.,
DunmoreBuyze P. J.,
Holdsworth D. W.,
Fenster A.
Publication year - 1997
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.598049
Subject(s) - imaging phantom , soft tissue , materials science , biomedical engineering , displacement (psychology) , radiography , calibration , subtraction , nuclear medicine , saline , digital radiography , medicine , mathematics , radiology , psychology , statistics , arithmetic , endocrinology , psychotherapist
A novel in vitro radiographic technique using saline/iodine displacement, which can be used to study the bone‐equivalent and soft‐tissue‐equivalent thicknesses within vessel walls, was applied to imaging of arterial specimens. Results concerning the accuracy and precision of the bone‐equivalent and soft‐tissue‐equivalent thickness measurements obtained with this technique are reported and discussed. Planar radiographs of a phantom were obtained under two different conditions: (1) when it is immersed in an isotonic saline solution using a 45 ‐ kVpspectrum with no added filtration, and (2) when it is immersed in a concentrated iodine solution using a 100 ‐ kV pspectrum with 12.5‐mm aluminum‐added filtration. Calibration step wedges made out of bone‐mimicking and soft‐tissue‐mimicking materials are imaged simultaneously to generate calibration curves that are used to convert the radiographs into bone‐equivalent and total‐thickness images. A soft‐tissue‐thickness image is obtained from the subtraction of the bone‐equivalent image from the total‐thickness image. Thickness measurements obtained from these images yielded average accuracies of ±110 μm for both the bone‐equivalent and the soft‐tissue‐equivalent images. The precision (one standard deviation) of the thickness measurements was ±60 and ±90 μm for the bone‐equivalent and the soft‐tissue‐equivalent images, respectively. In conclusion, since calcified plaque can become as thick as 3–4 mm, the saline/iodine displacement technique has the potential to be a very useful technique for ex vivo studies of the progression of atherosclerosis because of its high accuracy and precision.