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Comparison of reduced field‐of‐view diffusion‐weighted imaging (DWI) and conventional DWI techniques in the assessment of rectal carcinoma at 3.0T: Image quality and histological T staging
Author(s) -
Peng Yang,
Li Zhen,
Tang Hao,
Wang Yanchun,
Hu Xuemei,
Shen Yaqi,
Hu Daoyu
Publication year - 2018
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.25814
Subject(s) - medicine , nuclear medicine , diffusion mri , magnetic resonance imaging , wilcoxon signed rank test , image quality , colorectal cancer , effective diffusion coefficient , echo planar imaging , radiology , cancer , mann–whitney u test , image (mathematics) , artificial intelligence , computer science
Purpose To compare image quality (IQ) of reduced field‐of‐view (rFOV) and full FOV (fFOV) diffusion‐weighted imaging (DWI) sequences at 3T, with histological T staging of rectal cancer as a reference standard. Materials and Methods In all, 81 patients with rectal cancer received magnetic resonance (MR) scans (3.0T), including both rFOV and fFOV DWI sequences. The signal‐to‐noise ratio (SNR) and contrast‐to‐noise ratio (CNR) were quantitatively evaluated using the paired t ‐test. Two radiologists independently assessed subjective IQ parameters, including image sharpness, distortion, artifacts, lesion conspicuity, and overall subjective IQ of both sequences. The Wilcoxon signed rank test was used to compare subjective IQ scores and tumor apparent diffusion coefficients (ADCs) between DWI sequences. Spearman correlation analysis was used to correlate ADC values and corresponding T staging of rectal cancer. Results CNR was significantly higher in rFOV DWI than in fFOV DWI (7.15 ± 2.77 vs. 5.39 ± 2.08, P < 0.001). SNR was significantly higher in rFOV DWI than in fFOV DWI (44.17 ± 11.01 vs. 34.76 ± 13.30, P < 0.001). The subjective IQ parameters of rFOV DWI sequence were rated superior to those of fFOV DWI sequence by both readers ( P < 0.001). No significant differences between mean tumor ADC values of both sequences (0.991 ± 0.121 vs. 0.100 ± 0.126 × 10 ‐3 mm 2 /s, P = 0.617) were noted. Apart from T1 stage, T staging of rectal cancer was inversely correlated with ADC values of rFOV DWI ( r = –0.688, P < 0.001) and fFOV DWI sequences ( r = –0.641, P < 0.001). Conclusion The rFOV DWI sequence provided significantly better IQ and lesion conspicuity than the fFOV DWI sequence. In addition, rFOV and fFOV DWI sequences can be used in evaluation of histological T staging of rectal cancer. Level of Evidence: 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:967–975.