Warning: Declaration of My_Walker::start_el(&$output, $item, $depth, $args) should be compatible with Walker_Nav_Menu::start_el(&$output, $data_object, $depth = 0, $args = NULL, $current_object_id = 0) in /home2/ajnrblog/public_html/ajnrdigest/wp-content/themes/ajnr/functions.php on line 258
Apparent Diffusion Coefficient Mapping of Salivary Gland Tumors: Prediction of the Benignancy and Malignancy - AJNR News Digest
July 2014
Head & Neck

Apparent Diffusion Coefficient Mapping of Salivary Gland Tumors: Prediction of the Benignancy and Malignancy

Sato Eida

Sato Eida

Preoperative prediction of tumor malignancy is clinically very important, because this information strongly influences the surgical plan. Diffusion-weighted imaging is very sensitive to biophysical abnormalities associated with pathologic changes; in this regard, apparent diffusion coefficient measurement has been used to diagnose benign and malignant salivary gland tumors. However, salivary gland tumors are composed of distinctive tissues, including proliferating tumor cells, myxomatous tissues, lymphoid tissues, necrosis, and cysts. Analyzing a large region of interest in a histologically heterogeneous tumor may therefore result in spurious results with regard to the tumor histology. To avoid this potential error, tissue characterization using high-resolution MRI techniques is mandatory. In this study, we reasoned that the ADC mapping technique might enable effective characterization of the histologic features of salivary gland tumors. The ADC maps showed that a greater number of areas with high ADCs (≧1.8 × 10-3mm2/s) were significantly greater in benign tumors than in malignant tumors. The sensitivity and specificity for high ADC occupying fewer than 5% of the tumor area was 89% and 100%, respectively, resulting in 97% accuracy, 100% positive predictive value, and 96% negative predictive value. The results of our study suggest the feasibility of an ADC map in differentiating between benign and malignant diseases in the head and neck region.

After successful publication of the above paper, we also successfully applied DWI for the differentiation of benign lesions and malignant tumors in the sinonasal area.1

Furthermore, we proposed a stepwise approach by using multiparametric MRI techniques as an effective tool for differentiating between benign and malignant salivary gland tumors,2 where we evaluated a stepwise approach involving the combined use of dynamic contrast-enhanced and diffusion-weighted MRI. The multiparametric MRI also helps in distinguishing malignant thyroid nodules from benign ones, and in diagnosing head and neck tumors.3,4

References

  1. Sasaki M, Eida S, Sumi M, et al. Apparent diffusion coefficient mapping for sinonasal diseases: differentiation of benign and malignant lesions. AJNR Am J Neuroradiol 2011;32:1100–06, 10.3174/ajnr.A2434
  2. Eida S, Sumi M, Nakamura T. Multiparametric magnetic resonance imaging for the differentiation between benign and malignant salivary gland tumors. J Magn Reson Imaging 2010;31:673–79, 10.1002/jmri.22091
  3. Sasaki M, Sumi M, Kaneko K, et al. Multiparametric MR imaging for differentiating between benign and malignant thyroid nodules: initial experience in 23 patients. J Magn Reson Imaging 2013;38:64–71, 10.1002/jmri.23948
  4. Sumi M, Nakamura T. Head and neck tumours: combined MRI assessment based on IVIM and TIC analyses for the differentiation of tumors of different histological types. Eur Radiol 2014;24:223–31, 10.1007/s00330-013-3002-z

 

Read this article at AJNR.org . . .