Effect of b values and size of region of interest on apparent diffusion coefficient measurement and its reproducibility in liver diffusion-weighted MRI
Objectives To investigate the effect of b value and size of region of interest (ROI) on apparent diffusion coefficient (ADC) measurement and its reproducibility in liver diffusion-weighted imaging (DWI). Methods Thirty-six volunteers underwent liver DWI twice with b values of 0, 100, 500, and 800 s/...
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Published in | Chinese journal of academic radiology Vol. 4; no. 1; pp. 56 - 62 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Singapore
Springer Singapore
01.03.2021
|
Subjects | |
Online Access | Get full text |
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Summary: | Objectives
To investigate the effect of
b
value and size of region of interest (ROI) on apparent diffusion coefficient (ADC) measurement and its reproducibility in liver diffusion-weighted imaging (DWI).
Methods
Thirty-six volunteers underwent liver DWI twice with
b
values of 0, 100, 500, and 800 s/mm
2
. ADCs were measured with ROI of 50 mm
2
on ADC maps generated with different
b
values of (0, 100), (0, 500), (0, 800), (0, 100, 500), (0, 100, 800), (0, 500, 800), and (0, 100, 500, 800) s/mm
2
. ADCs from
b
values of (0, 800) s/mm
2
were measured with 4 ROI sizes (50, 100, 200 and 300 mm
2
). ANOVA analysis was used to compare differences of ADCs among different ROI sizes and different combined
b
values. Bland–Altman method was used to assess reproducibility of ADC measurement.
Results
ADCs with larger ROI size were slightly higher than those with smaller one, while no statistical difference was found (
P
> 0.05). And reproducibility of ADC measurement with different ROI sizes was comparable (LOA 7.0–8.2% for right lobe, 14.15–17.4% for left lobe). ADCs statistically decreased with increased maximum
b
values (
P
< 0.05). ADC measurement achieved the best reproducible with maximum
b
value of 800 s/mm
2
regardless of the number of
b
values.
Conclusions
The
b
values influence ADC measurement and its reproducibility, while the ROI sizes do not affect them. Two
b
values of (0, 800) s/mm
2
and ROI of 50 mm
2
are recommended for liver ADC measurement. |
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ISSN: | 2520-8985 2520-8993 |
DOI: | 10.1007/s42058-021-00053-7 |