rFOV-DWI and SMS-RESLOVE-DWI in patients with thyroid nodules: Comparison of image quality and apparent diffusion coefficient measurements.

Objectives: To compare reduced field of view technique diffusion-weighted imaging (rFOV-DWI) and simultaneous multislice readout segmentation of long variable echo-trains diffusion-weighted imaging (SMS-RESOLVE-DWI) in terms of image quality and diagnostic performance of the apparent diffusion coefficient (ADC) for thyroid nodules.

Materials And Methods: A total of 27 benign thyroid nodules and 26 malignant thyroid nodules were enrolled. rFOV-DWI and SMS-RESOLVE-DWI were performed at b values of 0 and 1000 s/mm. Subjective image quality was evaluated in terms of sharpness, distortion and artifacts. Objective indices reflecting distortion, the contrast-to-noise ratio and the ADC were measured. Paired-samples t-tests or Wilcoxon U tests were applied to assess whether significant differences existed among different sequences. According to the pathological results, the nodules were divided into the benign and malignant groups. The receiver operating characteristic (ROC) curve of the ADC values was used to predict malignant nodules. The DeLong test was used to compare the diagnostic effectiveness between rFOV-DWI and SMS-RESOLVE-DWI.

Results: The rFOV-DWI images exhibited better sharpness (P < 0.001) and fewer artifacts (P = 0.003) for the thyroid than the SMS-RESOLVE-DWI images. The overall image quality of nodules (P < 0.001) was better in rFOV-DWI images than in SMS-RESOLVE-DWI images. The rFOV-DWI images also showed less deformation than the SMS-RESOLVE-DWI images (P = 0.002, 0.006). The ADC values of both rFOV-DWI and SMS-RESOLVE-DWI revealed equivalent excellent diagnostic performance. The DeLong test revealed no statistically significant differences between rFOV-DWI and SMS-RESOLVE-DWI.

Conclusion: This study suggested that rFOV-DWI exhibited better image quality than SMS-RESOLVE-DWI and similar performance in differential diagnosis.