Multiple b values of diffusion-weighted magnetic resonance imaging in evaluation of solid head and neck masses

Abstract

Background: Differentiation between malignant and benign masses is essential for treatment planning and helps in improving the prognosis of malignant tumors; the aim of this work is to determine the role of diffusionweighted magnetic resonance imaging (DW-MRI) and the apparent diffusion coefficient (ADC) in the differentiation between benign and malignant solid head and neck masses by comparing diagnostic performance of low b values (0.50 and 400 s/mm 2) versus high b values (800 and 1000 s/mm 2) and comparing the result with histopathological finding. Results: The study included 60 patients (34 male and 26 female) with solid head and neck masses > 1 cm who referred to radiodiagnosis department for MRI evaluation. Multiple b values were used 50, 400, 800, and 1000 s/mm 2 (at least 2 b values). DWI and ADC value of all 60 patients were acquired. Mean ADC values of both malignant and benign masses were statistically measured and compared, and cut off value was determined. Solid head and neck masses in our study DWI with the use of high b value 800 and 1000 s/mm 2 were of higher significance (P value 0.001*). There was a significant difference in the mean ADC value between benign and malignant masses (P < 0.01); solid masses were divided into 2 categories: (a) malignant lesions 46.7% (n = 28) with mean ADC value (0.82 ± 0.19) × 10 −3 s/mm 2 and (b) benign lesions 53.3% (n = 32) with mean ADC value (2.05 ± 0.46) × 10 −3 s/mm 2) with ADC cutoff value of 1.0 × 10 −3 s/mm 2 and 94% sensitivity, 93% specificity, negative predictive value (NPV) = 94%, positive predictive value (PPV) 93%, and an accuracy of 93.5%. Conclusion: The DWI with ADC mapping were valuable as non-invasive tools in differentiating between benign and malignant solid head and neck masses. The use of high b value 800 and 1000 s/mm 2 was of higher significance (P value 0.001*) in differentiation between benign and malignant lesion than that with low b values 0, 50, and 400 s/mm 2 (0.01). The mean ADC values were significantly lower in malignant solid masses. Attention had to be paid to the choice of b values in MRI-DWI in the head and neck region.

Lymph nodes in the head and neck cancer: would diffusion-weighted magnetic resonance imaging solve the diagnostic dilemma?

“…Our study showed that the pathologically proven malignant lymph nodes (29 out of 30 cases) showed increased signal in b 1000, and low signal in the corresponding ADC maps, the inflammatory diseases (5 out of 6 cases), and reactive lymphoid hyperplasia (4 out of 4 cases) showed signal intensity reduction for increased b values (b = 1000) and intermediate signal intensity on ADC maps representing facilitated diffusion. Our study findings agreeing with Youssef et al [20] and Abou khadrah and Imam [12] that the DWI with ADC mapping were useful as non-invasive tools for distinguishing between the benign and malignant solid head and neck lesions by using b values 800 and 1000. The malignant lymph nodes in our sample had significantly lower ADCs than benign lymph nodes.…”

“…In our research, the mean ADC value of the 30 malignant lymph nodes was 0.971 ± 0.305 × 10 −3 mm 2 /s, while on the other hand, the mean ADC value of the 10 benign lymph nodes was 1.98 ± 0.33 ± 3 mm 2 /s with the threshold ADC value for separating malignant from benign nodes obtained from the receiver characteristic analysis being 1.30 × 10 −3 mm 2 /s with 94% sensitivity and 100% specificity. In agreement with Abou khadrah and Imam [12] who recorded 94% accuracy in characterizing the metastatic lymph nodes using a threshold of 1.0210 −3 mm 2 /s. The mean ADC values recorded for benign and metastatic lymph nodes were 1.…”

“…MRI sequences provided precise data regarding tumor size, site, and the head and cancer morphology. The diffusion-weighted imaging as a part of the MRI technique being a non-invasive tool without the definite need for administration of intravenous contrast agent had provided a reliable ability in the differentiation between the benign and malignant tissues [12].…”

Useful MRI Findings for Minimally Invasive Surgery for Early Cervical Cancer

“…Multi b-value DWI can reflect the early characteristics of water molecule diffusion in pathologic tissues because multi-exponential model DWI can provide more information than monoexponential model DWI [46][47][48]. Furthermore, high b values are superior at differentiating benign and malignant tumors compared with low b values [49].…”

Effects of fitting methods, high b-values and image quality on diffusion and perfusion quantification and reproducibility in the calf

“…Diffusion-weighted imaging (DWI) is a non-invasive means to measure the diffusion of water molecules in tissue water using magnetic resonance imaging (MRI) [1]. DWI is applied in oncology for the detection of malignant lesions [2], as water diffusion is significantly reduced in malignant tissues, and also in neurology for the detection of ischemia onset or to provide information on white matter structural integrity [1]. Quantitative evaluation of diffusion is achieved by acquiring multiple DWI images at different diffusion gradient strengths, named b-values.…”