PURPOSE: To compare two quantification techniques of apparent diffusion coefficient (ADC), both in normal liver parenchyma and focal lesions, and to investigate any potential value of normalization. MATERIALS AND METHODS: Fifty-six consecutive patients underwent MRI examination of the liver, including a single shot spin-echo echo planar imaging diffusion sequence with four b-values (0, 50, 500 and 1000s/mm(2)). ADC maps were reconstructed based on a two-point method (b-values: 500 and 1000s/mm(2)) and a four-point method (b-values: 0, 50, 500 and 1000s/mm(2)). Comparison of absolute ADC measurements of the liver, benign and malignant focal lesions was performed between the two- and four-point techniques. The same analysis was done on normalized ADC values (absolute ADC values divided by spleen ADC values). RESULTS: The difference between mean two-point and four-point ADC values of normal liver (absolute: 1.237x10(-3), 1.615x10(-3)mm(2)/s, normalized: 1.40, 1.52, respectively) was statistically significant (p<0.0001 and p=0.0061). Significantly higher absolute ADC values of benign and malignant lesions were recorded with the four-point method (2.860x10(-3) and 1.307x10(-3)mm(2)/s) over the two-point method (2.243x10(-3), and 1.011x10(-3)mm(2)/s) (p<0.0001 in both) while the same differences in normalized values were proven statistically non-significant for benign lesions (p=0.788) and statistically significant for malignant lesions (p=0.015). Both differences in absolute and normalized ADC values of benign versus malignant lesions based on two- and four-point methods were found to be significant (p<0.0001). CONCLUSION: ADC quantification of the liver may be performed with a two-point method (b-values of 500 and 1000s/mm(2)), while normalization of ADC measurements with the spleen is not further improving lesion characterization. Copyright (c) 2008 Elsevier Ireland Ltd. All rights reserved.
PURPOSE: To compare two quantification techniques of apparent diffusion coefficient (ADC), both in normal liver parenchyma and focal lesions, and to investigate any potential value of normalization. MATERIALS AND METHODS: Fifty-six consecutive patients underwent MRI examination of the liver, including a single shot spin-echo echo planar imaging diffusion sequence with four b-values (0, 50, 500 and 1000s/mm(2)). ADC maps were reconstructed based on a two-point method (b-values: 500 and 1000s/mm(2)) and a four-point method (b-values: 0, 50, 500 and 1000s/mm(2)). Comparison of absolute ADC measurements of the liver, benign and malignant focal lesions was performed between the two- and four-point techniques. The same analysis was done on normalized ADC values (absolute ADC values divided by spleen ADC values). RESULTS: The difference between mean two-point and four-point ADC values of normal liver (absolute: 1.237x10(-3), 1.615x10(-3)mm(2)/s, normalized: 1.40, 1.52, respectively) was statistically significant (p<0.0001 and p=0.0061). Significantly higher absolute ADC values of benign and malignant lesions were recorded with the four-point method (2.860x10(-3) and 1.307x10(-3)mm(2)/s) over the two-point method (2.243x10(-3), and 1.011x10(-3)mm(2)/s) (p<0.0001 in both) while the same differences in normalized values were proven statistically non-significant for benign lesions (p=0.788) and statistically significant for malignant lesions (p=0.015). Both differences in absolute and normalized ADC values of benign versus malignant lesions based on two- and four-point methods were found to be significant (p<0.0001). CONCLUSION: ADC quantification of the liver may be performed with a two-point method (b-values of 500 and 1000s/mm(2)), while normalization of ADC measurements with the spleen is not further improving lesion characterization. Copyright (c) 2008 Elsevier Ireland Ltd. All rights reserved.
Authors: Moti Freiman; Stephan D Voss; Robert V Mulkern; Jeannette M Perez-Rossello; Michael J Callahan; Simon K Warfield Journal: Med Phys Date: 2012-08 Impact factor: 4.071
Authors: Sara Reis Teixeira; Paula Condé Lamparelli Elias; Andrea Farias de Melo Leite; Tatiane Mendes Gonçalves de Oliveira; Valdair Francisco Muglia; Jorge Elias Junior Journal: Radiol Bras Date: 2016 Nov-Dec