Repeatability Investigation of Reduced Field-of-View Diffusion-Weighted Magnetic Resonance Imaging on Thyroid Glands

Abstract

Objective To investigate the repeatability of the quantitative magnetic resonance imaging (MRI) metric (apparent diffusion coefficient (ADC)) derived from reduced field-of-view diffusion-weighted (rFOV DWI) on thyroid glands in a clinical setting. Materials and Methods Ten healthy human volunteers were enrolled in MRI studies performed on a 3T MRI scanner. Each volunteer was designed to undergo 3 longitudinal exams (2 weeks apart) with 2 repetitive sessions within each exam, which included rFOV and conventional full field-of-view (fFOV) DWI scans. DWI images were assessed and scored based on image characteristics. ADC values of thyroid glands from all subjects were calculated based on regions of interest. Repeatability analysis was performed based on the framework proposed by the Quantitative Imaging Biomarker Alliance (QIBA), generating four repeatability metrics: within-subject variance (σw2), repeatability coefficients (RC), intraclass correlation coefficient (ICC) and within-subject coefficient of variation (wCV). Student t test was employed to compare the performance difference between rFOV and fFOV DWI. Results The overall image quality from rFOV DWI was significantly higher than that from fFOV DWI (p=0.04). The ADC values calculated from rFOV DWI were significantly lower than corresponding values from fFOV DWI (p<0.001). There was no significant difference in ADC values across sessions and exams in either rFOV or fFOV DWI (p>0.05). rFOV DWI had lower values of σw2, RC, and wCV and a higher value of ICC compared to fFOV DWI either across sessions and exams. Conclusion This study demonstrated that rFOV DWI produced more superior quality DWI images and more repeatable ADC measurements compared to fFOV DWI, thus providing a feasible quantitative imaging tool for investigating thyroid glands in clinical settings.

Feasibility study of reduced field of view diffusion-weighted magnetic resonance imaging in head and neck tumors

“…There have been very few studies published in the literature (11,23) using rFOV-DWI in the head and neck region, and those that exist were based on images acquired from a small number of volunteers, while investigations are still lacking in patients with head and neck clinical pathologies.…”

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

“…Riffel et al also reported that the ADC values of the pancreas were not significantly different between the two DWI methods. However, Lu et al discovered that the mean ADC values of thyroid glands based on the rFOV DWI sequence were significantly reduced compared with the values calculated based on the fFOV DWI sequence. Vidiri et al also reported that the mean ADC values of head and neck tumors were significantly different between DWI sequences.…”

“…Vidiri et al also reported that the mean ADC values of head and neck tumors were significantly different between DWI sequences. The reasons for the above ADC measurement disparities potentially include different physiologies of the investigated organs and the characteristic features of the rFOV DWI sequence in terms of artifact reduction, excellent fat saturation, and high resolution . In addition, the ADC value is influenced by numerous factors, such as the magnetic field strength, sequence protocols used, and b values .…”

“…The reasons for the above ADC measurement disparities potentially include different physiologies of the investigated organs and the characteristic features of the rFOV DWI sequence in terms of artifact reduction, excellent fat saturation, and high resolution. 33 In addition, the ADC value is influenced by numerous factors, such as the magnetic field strength, sequence protocols used, and b values. 29 Further assessment of ADC measurements of the rFOV DWI sequence in different organs is required for clarification.…”

Qualitative and quantitative comparison of image quality between single-shot echo-planar and interleaved multi-shot echo-planar diffusion-weighted imaging in female pelvis

“…[21,22] However, for patients with disseminate diseases, a reduced FOV cannot fulfill the clinical need for whole pelvic evaluation. Moreover, the mean tumor ADC obtained with zoomed EPI is not stable [23][24][25].…”