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Characterization of focal liver lesions using quantitative techniques: comparison of apparent diffusion coefficient values and T2 relaxation times.

Cieszanowski A, Anysz-Grodzicka A, Szeszkowski W, Kaczynski B, Maj E, Gornicka B, Grodzicki M, Grudzinski IP, Stadnik A, Krawczyk M, Rowinski O - Eur Radiol (2012)

Bottom Line: The mean ADC value of malignant tumours (1.07 × 10(-3) mm(2)/s) was significantly lower (P < 0.05) than that of benign lesions (1.86 × 10(-3) mm(2)/s ); however, with the use of the optimal cut-off value of 1.25 × 10(-3) mm(2)/s, 20 false positive (FP) and 20 false negative (FN) diagnoses of malignancy were noted, generating 79 % sensitivity, 82.6 % specificity and 80.9 % accuracy.The mean T2 relaxation time of malignant tumours (64.4 ms) was significantly lower (P < 0.05) than that of benign lesions (476.1 ms).At the threshold of 107 ms 22 FP and 1 FN diagnoses were noted; the sensitivity was 99 %, specificity 80.9 % and accuracy 89.3 %.

View Article: PubMed Central - PubMed

Affiliation: 2nd Department of Clinical Radiology, Medical University of Warsaw, Ul. Banacha 1A, 02-097, Warsaw, Poland. andrzej.cieszanowski@wum.edu.pl

ABSTRACT

Objectives: To compare the efficacy of two quantitative methods for discrimination between benign and malignant focal liver lesions (FLLs): apparent diffusion coefficient (ADC) values and T2 relaxation times.

Methods: Seventy-three patients with 215 confirmed FLLs (115 benign, 100 malignant) underwent 1.5-T MRI with respiratory-triggered single-shot SE DWI (b = 50, 400, 800) and dual-echo T2TSE (TR = 3,000 ms; TE1 = 84 ms; TE2 = 228 ms). ADC values and T2 relaxation times of FLLs were calculated. Sensitivity, specificity and accuracy of both techniques in diagnosing malignancy were assessed.

Results: The mean ADC value of malignant tumours (1.07 × 10(-3) mm(2)/s) was significantly lower (P < 0.05) than that of benign lesions (1.86 × 10(-3) mm(2)/s ); however, with the use of the optimal cut-off value of 1.25 × 10(-3) mm(2)/s, 20 false positive (FP) and 20 false negative (FN) diagnoses of malignancy were noted, generating 79 % sensitivity, 82.6 % specificity and 80.9 % accuracy. The mean T2 relaxation time of malignant tumours (64.4 ms) was significantly lower (P < 0.05) than that of benign lesions (476.1 ms). At the threshold of 107 ms 22 FP and 1 FN diagnoses were noted; the sensitivity was 99 %, specificity 80.9 % and accuracy 89.3 %.

Conclusions: Quantitative analysis of T2 relaxation times yielded significantly higher sensitivity and accuracy in diagnosing malignant liver tumour than ADC values.

Key points: • Diffusion-weighted magnetic resonance imaging is increasingly used for liver lesions. • But ADC values demonstrated only moderate accuracy for differentiation of liver lesions. • T2 relaxation times yielded higher accuracy in diagnosing malignant liver tumours. • Both ADC and T2 values overlapped between focal nodular hyperplasia and malignant lesions. • Nevertheless T2 liver mapping could be valuable for evaluating focal liver lesions.

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Box plots of T2 relaxation times of 115 benign and 100 malignant liver lesions show that T2 times of benign lesions were significantly higher than those of malignant tumours (p < 0.001), although there is some overlap. Median is shown as a small box inside (benign lesions) or outside (malignant lesions) bars. Nineteen benign lesions (18 cysts and 1 abscess) with T2 relaxation times above 1,000 ms were excluded from the plot for the sake of better visualisation
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Fig2: Box plots of T2 relaxation times of 115 benign and 100 malignant liver lesions show that T2 times of benign lesions were significantly higher than those of malignant tumours (p < 0.001), although there is some overlap. Median is shown as a small box inside (benign lesions) or outside (malignant lesions) bars. Nineteen benign lesions (18 cysts and 1 abscess) with T2 relaxation times above 1,000 ms were excluded from the plot for the sake of better visualisation

Mentions: The mean T2 relaxation time of malignant FLLs was lower than that of benign FLLs: 64.4 ms (range 45.83–117.49 ms) vs. 476.06 ms (range 49.87–2,630.82 ms) and the difference was statistically significant (P < 0.001; Fig. 2). The area under the ROC curve for diagnosing malignancy was 0.932 (95 % CI 0.891, 0.962), with sensitivity of 99 % and specificity of 80.9 %, using a threshold of 107 ms. The area under the ROC curve for T2 times was significantly larger (P < 0.001) than the area under the ROC curve for ADC values (Fig. 3).Fig. 2


Characterization of focal liver lesions using quantitative techniques: comparison of apparent diffusion coefficient values and T2 relaxation times.

Cieszanowski A, Anysz-Grodzicka A, Szeszkowski W, Kaczynski B, Maj E, Gornicka B, Grodzicki M, Grudzinski IP, Stadnik A, Krawczyk M, Rowinski O - Eur Radiol (2012)

Box plots of T2 relaxation times of 115 benign and 100 malignant liver lesions show that T2 times of benign lesions were significantly higher than those of malignant tumours (p < 0.001), although there is some overlap. Median is shown as a small box inside (benign lesions) or outside (malignant lesions) bars. Nineteen benign lesions (18 cysts and 1 abscess) with T2 relaxation times above 1,000 ms were excluded from the plot for the sake of better visualisation
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3472073&req=5

Fig2: Box plots of T2 relaxation times of 115 benign and 100 malignant liver lesions show that T2 times of benign lesions were significantly higher than those of malignant tumours (p < 0.001), although there is some overlap. Median is shown as a small box inside (benign lesions) or outside (malignant lesions) bars. Nineteen benign lesions (18 cysts and 1 abscess) with T2 relaxation times above 1,000 ms were excluded from the plot for the sake of better visualisation
Mentions: The mean T2 relaxation time of malignant FLLs was lower than that of benign FLLs: 64.4 ms (range 45.83–117.49 ms) vs. 476.06 ms (range 49.87–2,630.82 ms) and the difference was statistically significant (P < 0.001; Fig. 2). The area under the ROC curve for diagnosing malignancy was 0.932 (95 % CI 0.891, 0.962), with sensitivity of 99 % and specificity of 80.9 %, using a threshold of 107 ms. The area under the ROC curve for T2 times was significantly larger (P < 0.001) than the area under the ROC curve for ADC values (Fig. 3).Fig. 2

Bottom Line: The mean ADC value of malignant tumours (1.07 × 10(-3) mm(2)/s) was significantly lower (P < 0.05) than that of benign lesions (1.86 × 10(-3) mm(2)/s ); however, with the use of the optimal cut-off value of 1.25 × 10(-3) mm(2)/s, 20 false positive (FP) and 20 false negative (FN) diagnoses of malignancy were noted, generating 79 % sensitivity, 82.6 % specificity and 80.9 % accuracy.The mean T2 relaxation time of malignant tumours (64.4 ms) was significantly lower (P < 0.05) than that of benign lesions (476.1 ms).At the threshold of 107 ms 22 FP and 1 FN diagnoses were noted; the sensitivity was 99 %, specificity 80.9 % and accuracy 89.3 %.

View Article: PubMed Central - PubMed

Affiliation: 2nd Department of Clinical Radiology, Medical University of Warsaw, Ul. Banacha 1A, 02-097, Warsaw, Poland. andrzej.cieszanowski@wum.edu.pl

ABSTRACT

Objectives: To compare the efficacy of two quantitative methods for discrimination between benign and malignant focal liver lesions (FLLs): apparent diffusion coefficient (ADC) values and T2 relaxation times.

Methods: Seventy-three patients with 215 confirmed FLLs (115 benign, 100 malignant) underwent 1.5-T MRI with respiratory-triggered single-shot SE DWI (b = 50, 400, 800) and dual-echo T2TSE (TR = 3,000 ms; TE1 = 84 ms; TE2 = 228 ms). ADC values and T2 relaxation times of FLLs were calculated. Sensitivity, specificity and accuracy of both techniques in diagnosing malignancy were assessed.

Results: The mean ADC value of malignant tumours (1.07 × 10(-3) mm(2)/s) was significantly lower (P < 0.05) than that of benign lesions (1.86 × 10(-3) mm(2)/s ); however, with the use of the optimal cut-off value of 1.25 × 10(-3) mm(2)/s, 20 false positive (FP) and 20 false negative (FN) diagnoses of malignancy were noted, generating 79 % sensitivity, 82.6 % specificity and 80.9 % accuracy. The mean T2 relaxation time of malignant tumours (64.4 ms) was significantly lower (P < 0.05) than that of benign lesions (476.1 ms). At the threshold of 107 ms 22 FP and 1 FN diagnoses were noted; the sensitivity was 99 %, specificity 80.9 % and accuracy 89.3 %.

Conclusions: Quantitative analysis of T2 relaxation times yielded significantly higher sensitivity and accuracy in diagnosing malignant liver tumour than ADC values.

Key points: • Diffusion-weighted magnetic resonance imaging is increasingly used for liver lesions. • But ADC values demonstrated only moderate accuracy for differentiation of liver lesions. • T2 relaxation times yielded higher accuracy in diagnosing malignant liver tumours. • Both ADC and T2 values overlapped between focal nodular hyperplasia and malignant lesions. • Nevertheless T2 liver mapping could be valuable for evaluating focal liver lesions.

Show MeSH
Related in: MedlinePlus