Diffusion Magnetic Resonance Imaging in the Head and Neck

Correlation of Apparent Diffusion Coefficient at 3T with Prognostic Parameters of Retinoblastoma

“…The ADC value of well-or moderately differentiated malignancies has been demonstrated to be significantly different from that of poorly differentiated cancers in many different regions of the body. 14,15,23 In this study, the ADC value of poorly and undifferentiated retinoblastoma is statistically different (P ϭ .007) from well-and moderately differentiated tumors. Hypercellularity and enlarged nuclei of poorly differentiated retinoblastomas reduce the extracellular matrix and the diffusion space of water protons in the extracellular and intracellular dimensions, with a resultant decrease in the ADC value of the tumor.…”

“…Poorly differentiated tumors are composed of small round cells with a high nuclear to cytoplasmic ratio and hyperchromatic nuclei that are devoid of Flexner-Wintersteiner rosettes and fleurettes. 28,29 Diffusion-weighted MR imaging is a fast sequence that can be added to routine MR imaging and may provide information about cellularity of the tumor 14,15 via the ADC value; the ADC value is correlated with tumor differentiation and this information cannot be obtained with conventional MR imaging. The ADC value of well-or moderately differentiated malignancies has been demonstrated to be significantly different from that of poorly differentiated cancers in many different regions of the body.…”

“…[14][15][16][17] Recent advances in MR software technology at 3T will likely continue to improve image quality and also promise the potential application of multiple and higher b-values than 1000 mm 2 /s, which may increase diffusion sensitivity and allow further characterization of these tumors on the basis of ADC.…”

“…6,7 Imaging parameters with prognostic value have also been identified; for example, the degree of contrast enhancement of the anterior eye segment at MR imaging correlates with iris neovascularization, and this is associated with an increased risk of tumor recurrence and metastatic disease. [11][12][13] Diffusion-weighted MR imaging is a promising tool in the evaluation of head and neck malignancy 14,15 and orbital disease. Diffusion-weighted MR imaging has been used in evaluation of orbital tumors of adults 16,17 and children, 18 ocular adnexal lymphomas, 19 endophtalmitis, 20 and optic nerve lesions.…”

Difusion-Weighted MRI: from Brownian Motion to Head and Neck Tumor Characterization

“…The variation in motion and redistribution of water molecules between tissue compartments that is reflected in DW Imaging and ADC values helps to differentiate disease processes [5] and to characterize tissues, providing complementary information to conventional structural MR imaging [8].…”