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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 a 51-year-old woman with liver metastases from neuroendocrine cancer. 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. The first metastatic lesion (arrow) displaying increased signal intensity on b = 50 and b = 800 images and on ADC map had an ADC value of 1.43 × 10−3 mm2/s (false negative diagnosis of malignancy). The second lesion (arrowhead) shows increased signal intensity on b = 50 and b = 800 images and decreased signal on ADC map consistent with restricted diffusion (ADC value = 1.24 × 10−3 mm2/s). Both lesions had T2 relaxation times in the range of those of a malignant lesion (58.9 ms and 98.6 ms)
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Fig4: MR images obtained in a 51-year-old woman with liver metastases from neuroendocrine cancer. 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. The first metastatic lesion (arrow) displaying increased signal intensity on b = 50 and b = 800 images and on ADC map had an ADC value of 1.43 × 10−3 mm2/s (false negative diagnosis of malignancy). The second lesion (arrowhead) shows increased signal intensity on b = 50 and b = 800 images and decreased signal on ADC map consistent with restricted diffusion (ADC value = 1.24 × 10−3 mm2/s). Both lesions had T2 relaxation times in the range of those of a malignant lesion (58.9 ms and 98.6 ms)

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 a 51-year-old woman with liver metastases from neuroendocrine cancer. 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. The first metastatic lesion (arrow) displaying increased signal intensity on b = 50 and b = 800 images and on ADC map had an ADC value of 1.43 × 10−3 mm2/s (false negative diagnosis of malignancy). The second lesion (arrowhead) shows increased signal intensity on b = 50 and b = 800 images and decreased signal on ADC map consistent with restricted diffusion (ADC value = 1.24 × 10−3 mm2/s). Both lesions had T2 relaxation times in the range of those of a malignant lesion (58.9 ms and 98.6 ms)
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Related In: Results  -  Collection

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Fig4: MR images obtained in a 51-year-old woman with liver metastases from neuroendocrine cancer. 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. The first metastatic lesion (arrow) displaying increased signal intensity on b = 50 and b = 800 images and on ADC map had an ADC value of 1.43 × 10−3 mm2/s (false negative diagnosis of malignancy). The second lesion (arrowhead) shows increased signal intensity on b = 50 and b = 800 images and decreased signal on ADC map consistent with restricted diffusion (ADC value = 1.24 × 10−3 mm2/s). Both lesions had T2 relaxation times in the range of those of a malignant lesion (58.9 ms and 98.6 ms)
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