Time‐dependent diffusion MRI to distinguish malignant from benign head and neck tumors

Abstract

Background There is growing interest in the effect of diffusion time on apparent diffusion coefficient (ADC) values in cancers; however, little evidence exists regarding its utility to differentiate malignant from benign head and neck tumors. Purpose To investigate the utility of ADC value changes in distinguishing between malignant and benign head and neck tumors using the different diffusion times obtained from oscillating gradient spin‐echo (OGSE) and pulsed gradient spin‐echo (PGSE) MRI sequences. Study Type Prospective. Subjects Thirty‐one consecutive patients with suspected head and neck tumors and a phantom. Field Strength/Sequence 3T MRI with diffusion‐weighted imaging (DWI) using OGSE (effective diffusion time: 4.3 msec) and PGSE (effective diffusion time: 82.6 msec) sequences and b‐values of 0 and 700 s/mm2. Assessment ADC values using OGSE (ADCOGSE) and PGSE (ADCPGSE) and relative ADC value changes between ADCOGSE and ADCPGSE. Statistical Tests Wilcoxon test, Mann–Whitney test, and McNemar test. Results Relative ADC changes for each polyvinylpyrrolidone (PVP) and water in the phantom between OGSE and PGSE sequences were small (relative ADC change within 0.6%). Malignant tumors had significantly smaller ADCOGSE and ADCPGSE values than benign tumors (P < 0.001 and < 0.0001, respectively). Significantly larger relative ADC changes were observed in malignant compared with benign head and neck tumors (P < 0.0001). ADCPGSE values were significantly lower than ADCOGSE values in both malignant and benign head and neck tumors (0.97 vs. 1.28 × 10−3mm2/s: P < 0.0001 and 1.93 vs. 1.99 × 10−3mm2/s: P = 0.0056, respectively). Relative ADC change and ADCPGSE tended to have higher diagnostic performance than ADCOGSE, with area under the curve (AUC) values of 0.97, 0.96, and 0.89, respectively. Data Conclusion ADC values obtained using the PGSE sequence were lower than those obtained with OGSE. This difference was larger for malignant than benign tumors, suggesting differences in tissue structure (diffusion hindrance) or cell permeability, revealed by changes in diffusion time. The results underline the potential importance of reporting diffusion time for interpretation of head and neck diffusion MRI. Level of Evidence: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:88–95.

Investigation of Breast Cancer Microstructure and Microvasculature from Time-Dependent DWI and CEST in Correlation with Histological Biomarkers

“…The observed decrease in ADC and sADC values with T d in breast tumors was in agreement with the literature, as were the results of our previous investigation 11,32,42 . This con rms the hypothesis that diffusion hindrance in tumors increases when the T d value increases, as more molecules might hit the increased number of obstacles such as cell membranes.…”

“…Several studies have reported that various types of malignant tumors revealed the decrease in ADC values with long T d [10][11][12][13] .…”

Feasibility of oscillating and pulsed gradient diffusion MRI to assess neonatal hypoxia-ischemia on clinical systems

“…in tumor applications. 25,26,28 Here we demonstrated the technical feasibility and clinical utility of t d -dependent dMRI in neonatal HIE, which is a potentially favorable application as the high ADC and T2 relaxation time in the neonatal brain mitigated the technical issues of OG-dMRI. We were able to reliably detect t d -dependence from PG-and OG-dMRI measurements in the neonatal brain tissues, and we found higher DADC in the subcortical WM compared to deep GM.…”

“…Therefore, the performance of OG-dMRI is limited by the relatively low gradient strength on clinical systems, which leads to the limited oscillating frequency range, low b-value, and low signal-to-noise ratio (SNR). Nevertheless, OG-dMRI has been attempted in tumor, [25][26][27][28] stroke patients, 29,30 and healthy adult brain 31,32 given these technical limitations. Particularly, Baron et al 29 performed OG and PG-dMRI scans in 11 stroke patients and the results suggested that the ADC differences between OG and PG scans, which represented the t d -dependence, increased in the lesion areas.…”

ADC on Diffusion Imaging: The MR Analog of SUV on FDG‐PET: Perfect Is the Enemy of Good

“…That does not disregard that technical innovation of new sequences or the improvement of quantitative accuracy; however, it underlines that the accuracy is only a piece of the big picture. Reproducibility, scalability, adaptability, and generalizability are also essential when faced with clinical implementation.…”