Multi‐system repeatability and reproducibility of apparent diffusion coefficient measurement using an ice‐water phantom

Abstract

Purpose Quantitative quality control procedures were sought to evaluate technical variability in multi-center measurements of the diffusion coefficient of water as a prerequisite to use of the biomarker apparent diffusion coefficient (ADC) in multi-center clinical trials. Materials and Methods A uniform data acquisition protocol was developed and shared with 18 participating test sites along with a temperature-controlled diffusion phantom delivered to each site. Usable diffusion weighted imaging data of ice water at 5 b-values were collected on 35 clinical MRI systems from 3 vendors at 2 field strengths (1.5 and 3T) and analyzed at a central processing site. Results Standard deviation of bore-center ADCs measured across 35 scanners was <2%; error range: −2% to +5% from literature value. Day-to-day repeatability of the measurements was within 4.5%. Intra-exam repeatability at the phantom center was within 1%. Excluding one outlier, inter-site reproducibility of ADC at magnet isocenter was within 3%, though variability increased for off-center measurements. Significant (>10%) vendor-specific and system-specific spatial non-uniformity ADC bias was detected for the off-center measurement that was consistent with gradient non-linearity. Conclusion Standardization of DWI protocol has improved reproducibility of ADC measurements and allowed identifying spatial ADC non-uniformity as a source of error in multi-site clinical studies.

Using Diffusion-Weighted MRI to Predict Aggressive Histological Features in Papillary Thyroid Carcinoma: A Novel Tool for Pre-Operative Risk Stratification in Thyroid Cancer

“…1) in the ice-water phantom at four repeat scans were 1.113, 1.112, 1.113, and 1.112 · 10 -3 mm 2 /s, respectively. These ADC values were consistent with the literature (33,34), showing that the ADC measurement was highly reproducible in DW-MRI. In another study with healthy volunteers, the ADC values of thyroid gland from 9 volunteers across the exams were 1.84 -0.33 vs 1.74 -0.27 vs 1.74 - 2 /s (0.77 -0.14); p < 0.01 ( p < 0.001)].…”

Correlation of the Apparent Diffusion Coefficient (ADC) with the Standardized Uptake Value (SUV) in Hybrid 18F-FDG PET/MRI in Non-Small Cell Lung Cancer (NSCLC) Lesions: Initial Results

“…Future studies are required to investigate this issue, as a high robustness is a prerequisite for the use of DWI in treatment monitoring. A recently published study using an ice water phantom has demonstrated that DWI data acquisition using a DWI protocol designed for comparability across scanners might compensate differences in scanner geometry leading to a high robustness of ADC measurements [40]. However, based on our data, studies on the combined use of ADC and SUV values derived from PET/MRI for the prediction of therapy response are rewarded.…”

Diffusion-weighted magnetic resonance imaging in cancer: Reported apparent diffusion coefficients,in-vitroandin-vivoreproducibility

“…The authors reported a ± 5% variation in ADC across all systems and singlesystem repeatability was also ± 5%. Malyarenko et al [137] (2013) reported a multi-centre study using a variation of the ice-water phantom developed by Chenevert et al [125] . The authors devised a DW-MRI protocol compatible across 35 clinical MRI platforms (GE, Philips, Siemens) at 18 institutions at two field strengths of 1.5T and 3.0T.…”