DW-MRI of liver lesions: can a single ADC-value represent the entire lesion?
C Schmid-Tannwald1, F Dahi2, Y Jiang2
1Department of Radiology, The University of Chicago, Chicago, IL, USA; Ludwig-Maximilians-University Hospital Munich, Institute for Clinical Radiology, Munich, Germany.
Aim:
To evaluate whether focal liver lesions (FLLs) exhibit a homogeneous appearance on apparent diffusion coefficient (ADC) maps and whether there is inter-section variation in the calculated ADC values of FLLs (inter-section range).
Materials And Methods:
Eighty-eight patients with 128 FLLs (70 benign, 58 malignant) who underwent abdominal magnetic resonance imaging (MRI) including diffusion-weighted (DW)-MRI were included. Two observers evaluated variation of signal intensity of each FLL within each ADC map image (intra-section) and among different ADC map images through the lesion (inter-section). ADC values of each FLL and neighbouring liver parenchyma were measured on all sections. The inter-section range of FLLs was compared with the neighbouring liver parenchyma.
Results:
Intra-section inhomogeneity was noted in 39.8% (97/244 sections) and 38.9% (95/244) of benign lesions, and 61% (114/187 sections) and 61.5% (115/187) of malignant lesions, by observer 1 and observer 2, respectively. Inter-section inhomogeneity was noted in 25.7% (18/70) and 27.1% (19/70) of benign lesions, and 51.7% (30/58) and 50% (29/58) of malignant lesions, by observer 1 and observer 2, respectively. The inter-section range for both benign (0.28 × 10(-3) mm(2)/s) and malignant (0.25 × 10(-3) mm(2)/s) FLLs were significantly greater than that of liver parenchyma surrounding benign (0.16 × 10(-3) mm(2)/s, p < 0.001) and malignant (0.14 × 10(-3) mm(2)/s, p = 0.01) FLLs.
Conclusion:
Due to intra-/inter-section variations in ADC values of benign and malignant FLLs, a single ADC value may not reliably represent the entire lesion.
Insights
Focal liver lesions (FLLs) show significant variations in apparent diffusion coefficient (ADC) values within and between imaging sections. This inhomogeneity means a single ADC measurement may not accurately represent the entire FLL, impacting diagnostic interpretation.
Area of Science:
- Radiology
- Medical Imaging
- Oncology
Background:
- Focal liver lesions (FLLs) require accurate characterization for diagnosis and management.
- Apparent diffusion coefficient (ADC) mapping in diffusion-weighted magnetic resonance imaging (DW-MRI) is a key technique for evaluating FLLs.
- Understanding the variability of ADC values within FLLs is crucial for reliable interpretation.
Purpose of the Study:
- To assess the homogeneity of FLLs on ADC maps.
- To quantify the inter-section variation (range) of ADC values within FLLs.
- To compare the inter-section ADC variability of FLLs with that of surrounding liver parenchyma.
Main Methods:
- Retrospective analysis of abdominal DW-MRI from 88 patients with 128 FLLs (70 benign, 58 malignant).
- Two observers evaluated intra-section and inter-section signal intensity variations within FLLs.
- ADC values of FLLs and adjacent liver parenchyma were measured across all sections; inter-section ranges were compared.
Main Results:
- Both benign and malignant FLLs demonstrated significant intra-section and inter-section inhomogeneity in ADC values.
- Inter-section inhomogeneity was observed in 25.7-27.1% of benign FLLs and 50-51.7% of malignant FLLs.
- The inter-section ADC range for both benign and malignant FLLs was significantly larger than that of the surrounding liver parenchyma.
Conclusions:
- Intra- and inter-section variations in ADC values are common in both benign and malignant FLLs.
- A single ADC value may not be representative of the entire FLL due to this variability.
- These findings highlight the importance of considering ADC value heterogeneity in the interpretation of FLLs.
