Distortion correction of echo-planar diffusion-weighted images of uterine cervix.
Abstract
PURPOSE: To investigate the clinical utility of the reverse gradient algorithm in correcting distortions in diffusion-weighted images of the cervix and for increasing diagnostic performance. MATERIALS AND METHODS: Forty-one patients ages 25-72 years (mean 40 ± 11 years) with suspected or early stage cervical cancer were imaged at 3T using an endovaginal coil. T2 -weighted (W) and diffusion-weighted images with right and left phase-encode gradient directions were obtained coronal to the cervix (b = 0, 100, 300, 500, 800 s mm(-2) ). Differences in angle of the endocervical canal to the x-axis between T2 W and right-gradient, left-gradient, and corrected images were measured. Uncorrected and corrected images were assessed for diagnostic performance when viewed together with T2 W images by two independent observers against subsequent histology. RESULTS: The angles of the endocervical canal relative to the x-axis were significantly different between the T2 W images and the right-gradient images (P = 0.007), approached significance for left-gradient images (P = 0.055), and were not significantly different after correction (P = 0.95). Corrected images enabled a definitive diagnosis in 34% (n = 14) of patients classified as equivocal on uncorrected images. Tumor volume in this subset was 0.18 ± 0.44 cm(3) (mean ± SD; sensitivity of detection 100% [8/8], specificity 50% [3/6] for an experienced observer). Correction did not improve diagnostic performance for the less-experienced observer. CONCLUSION: Distortion-corrected diffusion-weighted images improved correspondence with T2 W images and diagnostic performance in a third of cases.
Collections
Subject
Cervix Uteri
Humans
Observer Variation
Diffusion Magnetic Resonance Imaging
Echo-Planar Imaging
Prospective Studies
Algorithms
Image Processing, Computer-Assisted
Adult
Aged
Middle Aged
Uterine Cervical Neoplasms
Female
Male
Research team
Magnetic Resonance
Language
eng
Date accepted
2015-10-06
License start date
2016-05
Citation
Journal of magnetic resonance imaging : JMRI, 2016, 43 (5), pp. 1218 - 1223
Publisher
WILEY-BLACKWELL