Dataset Information

A potential risk of overestimating apparent diffusion coefficient in parotid glands.

ABSTRACT:

Objectives

To investigate transient signal loss on diffusion weighted images (DWI) and overestimation of apparent diffusion coefficient (ADC) in parotid glands using single shot echoplanar DWI (EPDWI).

Materials and methods

This study enrolled 6 healthy subjects and 7 patients receiving radiotherapy. All participants received dynamic EPDWI with a total of 8 repetitions. Imaging quality of DWI was evaluated. Probability of severe overestimation of ADC (soADC), defined by an ADC ratio more than 1.2, was calculated. Error on T2WI, DWI, and ADC was computed. Statistical analysis included paired Student t testing and Mann-Whitney U test. A P value less than 0.05 was considered statistically significant.

Results

Transient signal loss was visually detected on some excitations of DWI but not on T2WI or mean DWI. soADC occurred randomly among 8 excitations and 3 directions of diffusion encoding gradients. Probability of soADC was significantly higher in radiotherapy group (42.86%) than in healthy group (24.39%). The mean error percentage decreased as the number of excitations increased on all images, and, it was smallest on T2WI, followed by DWI and ADC in an increasing order.

Conclusions

Transient signal loss on DWI was successfully detected by dynamic EPDWI. The signal loss on DWI and overestimation of ADC could be partially remedied by increasing the number of excitations.

SUBMITTER: Liu YJ

PROVIDER: S-EPMC4414616 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature

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Publications

A potential risk of overestimating apparent diffusion coefficient in parotid glands.

Liu Yi-Jui YJ Lee Yi-Hsiung YH Chang Hing-Chiu HC Huang Teng-Yi TY Chiu Hui-Chu HC Wang Chih-Wei CW Chiou Ta-Wei TW Hsu Kang K Juan Chun-Jung CJ Huang Guo-Shu GS Hsu Hsian-He HH

PloS one 20150429 4

<h4>Objectives</h4>To investigate transient signal loss on diffusion weighted images (DWI) and overestimation of apparent diffusion coefficient (ADC) in parotid glands using single shot echoplanar DWI (EPDWI).<h4>Materials and methods</h4>This study enrolled 6 healthy subjects and 7 patients receiving radiotherapy. All participants received dynamic EPDWI with a total of 8 repetitions. Imaging quality of DWI was evaluated. Probability of severe overestimation of ADC (soADC), defined by an ADC rat ...[more]

PMID: 25922948

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Dataset Information

A potential risk of overestimating apparent diffusion coefficient in parotid glands.

Objectives

Materials and methods

Results

Conclusions

Publications

A potential risk of overestimating apparent diffusion coefficient in parotid glands.

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