Prospective comparison of synthetic high b-value field of view optimized and constrained undistorted multiplexed...

Cervical cancer affects women's health worldwide. Accurate diagnosis based on the International Federation of Obstetrics and Gynecology (FIGO) is crucial for selecting treatment strategies for cervical cancer. Compared to conventional diffusion-weighted imaging (DWI) with a b-value of 800 s/mm², using b-values higher than 1,000 s/mm² can effectively reduce T2 effects, increase contrast between tumors and normal tissues, and thus improve the diagnostic reliability of malignant tumors. However, direct acquisition of high b-value DWI typically requires longer scanning time and a relatively lower signal-to-noise ratio (SNR). The synthetic high b-value DWI (syDWI) generated by fitting signal attenuation curves of 2 to 5 different b-values can avoid the drawbacks of actual scanning of high b-value images and obtain higher image quality without additional scanning time. Its accuracy in tumor detection and diagnosis is superior or comparable to that of actual scanning of high b-value DWI. The aim of the study was to explore the feasibility of synthetic high-b-value field of view optimized and constrained undistorted multiplexed sensitivity encoding diffusion-weighted imaging (FOCUS-MUSE DWI) in diagnosing cervical cancer using FOCUS DWI as reference.

A total of 55 patients with cervical cancer and 33 volunteers prospectively underwent FOCUS-MUSE DWI and FOCUS DWI with a 5b-protocol: b =0, 100, 400, 800, 1,200 s/mm². Two experienced radiologists conducted subjective and objective evaluation on sFOCUS-MUSE DWI_{b =800}, sFOCUS DWI_{b =800}, syFOCUS-MUSE DWI_{b =1,500}, and syFOCUS DWI_{b =1,500} as well as measured corresponding apparent diffusion coefficient (ADC) values. Inter-reader agreements of subjective and objective assessment were analyzed respectively using interclass correlation coefficient (ICC) and kappa statistics; comparison of image quality and ADC values was carried out using paired t-test, Wilcoxon signed rank test, or Mann Whitney U; and diagnostic efficiency was calculated using receiver operating characteristic (ROC) curve.

The sFOCUS-MUSE DWI_{b =800} and syFOCUS-MUSE DWI_{b =1,500} had higher subjective image quality (susceptibility artifacts, geometric distortion, anatomy details, and overall image quality) but lower SNR than sFOCUS DWI_{b =800} and syFOCUS DWI_{b =1,500} (all P<0.001). In the pooled cohort of patients and healthy volunteers (n=88), FOCUS-MUSE DWI generated significantly lower ADC values than conventional FOCUS at both b-values (b =800 s/mm², P=0.025; b =1,500 s/mm², P=0.001). The late-stage group (IIB-IV) showed lower ADC values than the early-stage group (IB-IIA) and healthy controls using each scanned and synthetic DWIs (all P<0.001). FOCUS-MUSE-syADC_{b =1,500} had equivalent AUCs to FOCUS-MUSE-syADC_{b =1,500}, FOCUS-sADC_{b =800}, and FOCUS-syADC_{b =800}.

FOCUS-MUSE DWI provides better image quality for evaluating cervical cancer and well diagnostic performance than FOCUS DWI. Synthetic high-b-value FOCUS-MUSE DWI takes no additional scan time and offers syADC values with reliable discrimination ability of cervical cancer with different FIGO stages.