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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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MR images obtained in an 83-year-old man with hepatic abscesses located in segment VIII. ab = 50 s/mm2 DW SS EPI image. bb = 800 s/mm2 DW SS EPI image. c Corresponding ADC map. Double echo TSE images: d TR/TE 3,000/84 ms, e TR/TE 3,000/228 ms. On DW images (b = 50, b = 800) the cavity of the first abscess (arrow) displays high signal intensity, which markedly decreases on ADC map, representing restricted diffusion (ADC value of 0.94 × 10−3 mm2/s—false positive diagnosis of malignancy). The cavity of the second abscess (arrowhead) shows increased signal on b = 50 DW image, mixed on b = 800 DW image and mostly increased on ADC map (ADC value of 1.27 × 10−3 mm2/s in the range of those of benign lesions). On axial T2-weighted images obtained with TE of 84 ms (d) and 228 ms (e) increased signal in noted in both cavities corresponding to relative long T2 times of 293 ms and 238 ms, typical for benign lesions. Abscesses demonstrate typical peripheral capsular enhancement on portal phase 3D GRE axial image (f)
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Fig6: MR images obtained in an 83-year-old man with hepatic abscesses located in segment VIII. ab = 50 s/mm2 DW SS EPI image. bb = 800 s/mm2 DW SS EPI image. c Corresponding ADC map. Double echo TSE images: d TR/TE 3,000/84 ms, e TR/TE 3,000/228 ms. On DW images (b = 50, b = 800) the cavity of the first abscess (arrow) displays high signal intensity, which markedly decreases on ADC map, representing restricted diffusion (ADC value of 0.94 × 10−3 mm2/s—false positive diagnosis of malignancy). The cavity of the second abscess (arrowhead) shows increased signal on b = 50 DW image, mixed on b = 800 DW image and mostly increased on ADC map (ADC value of 1.27 × 10−3 mm2/s in the range of those of benign lesions). On axial T2-weighted images obtained with TE of 84 ms (d) and 228 ms (e) increased signal in noted in both cavities corresponding to relative long T2 times of 293 ms and 238 ms, typical for benign lesions. Abscesses demonstrate typical peripheral capsular enhancement on portal phase 3D GRE axial image (f)

Mentions: With the use of ADC values 20 false positive diagnoses of malignant lesions (9 FNHs, 6 haemangiomas, 3 abscesses, 2 cysts) and 21 false negative cases (13 metastases, 7 haemangioendotheliomas, 1 cystadenocarcinoma) were noted (Figs. 4, 5 and 6). Therefore, a total of 41 FLLs were misclassified using ADC quantifications. The primary sites of 13 misclassified metastatic lesions included neuroendocrine tumour (n = 5; Fig. 4), pancreatic adenocarcinoma (n = 4), colorectal carcinoma (n = 3) and sarcoma (n = 1).Fig. 4


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)

MR images obtained in an 83-year-old man with hepatic abscesses located in segment VIII. ab = 50 s/mm2 DW SS EPI image. bb = 800 s/mm2 DW SS EPI image. c Corresponding ADC map. Double echo TSE images: d TR/TE 3,000/84 ms, e TR/TE 3,000/228 ms. On DW images (b = 50, b = 800) the cavity of the first abscess (arrow) displays high signal intensity, which markedly decreases on ADC map, representing restricted diffusion (ADC value of 0.94 × 10−3 mm2/s—false positive diagnosis of malignancy). The cavity of the second abscess (arrowhead) shows increased signal on b = 50 DW image, mixed on b = 800 DW image and mostly increased on ADC map (ADC value of 1.27 × 10−3 mm2/s in the range of those of benign lesions). On axial T2-weighted images obtained with TE of 84 ms (d) and 228 ms (e) increased signal in noted in both cavities corresponding to relative long T2 times of 293 ms and 238 ms, typical for benign lesions. Abscesses demonstrate typical peripheral capsular enhancement on portal phase 3D GRE axial image (f)
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3472073&req=5

Fig6: MR images obtained in an 83-year-old man with hepatic abscesses located in segment VIII. ab = 50 s/mm2 DW SS EPI image. bb = 800 s/mm2 DW SS EPI image. c Corresponding ADC map. Double echo TSE images: d TR/TE 3,000/84 ms, e TR/TE 3,000/228 ms. On DW images (b = 50, b = 800) the cavity of the first abscess (arrow) displays high signal intensity, which markedly decreases on ADC map, representing restricted diffusion (ADC value of 0.94 × 10−3 mm2/s—false positive diagnosis of malignancy). The cavity of the second abscess (arrowhead) shows increased signal on b = 50 DW image, mixed on b = 800 DW image and mostly increased on ADC map (ADC value of 1.27 × 10−3 mm2/s in the range of those of benign lesions). On axial T2-weighted images obtained with TE of 84 ms (d) and 228 ms (e) increased signal in noted in both cavities corresponding to relative long T2 times of 293 ms and 238 ms, typical for benign lesions. Abscesses demonstrate typical peripheral capsular enhancement on portal phase 3D GRE axial image (f)
Mentions: With the use of ADC values 20 false positive diagnoses of malignant lesions (9 FNHs, 6 haemangiomas, 3 abscesses, 2 cysts) and 21 false negative cases (13 metastases, 7 haemangioendotheliomas, 1 cystadenocarcinoma) were noted (Figs. 4, 5 and 6). Therefore, a total of 41 FLLs were misclassified using ADC quantifications. The primary sites of 13 misclassified metastatic lesions included neuroendocrine tumour (n = 5; Fig. 4), pancreatic adenocarcinoma (n = 4), colorectal carcinoma (n = 3) and sarcoma (n = 1).Fig. 4

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