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Use of Electromagnetic Navigational Transthoracic Needle Aspiration (E-TTNA) for Sampling of Lung Nodules
Published on: May 23, 2015
Hounsfield Unit Dynamics During CT-Guided Transthoracic Core Needle Biopsy as a Predictor of Malignant vs.
Mustafa Yeşilyurt1, Buğra Kerget2, Özlem Küçükoğlu1
1Department of Radiology, Faculty of Medicine, Atatürk University, 25040 Erzurum, Turkey.
Aims/Background:
Hounsfield unit (HU) measurements on computed tomography (CT) offer quantitative information on tissue composition, yet their dynamic changes during CT-guided transthoracic core needle biopsy (TCNB) have not been previously investigated. This study aimed to determine whether the post-biopsy change in HU (ΔHU) at the needle tract can predict histopathological outcomes in thoracic lesions, serving as a surrogate marker of tissue viability and vascularity.
Methods:
This study retrospectively included 166 patients who underwent CT-guided TCNB between June 2023 and November 2025. Non-contrast CT images (2-mm slices) obtained immediately before and after biopsy were analyzed. Regions of interest were placed along the biopsy tract, avoiding air and necrotic components. ΔHU was calculated by subtracting pre-biopsy from post-biopsy HU values. Two radiologists independently measured HU, with excellent interobserver agreement (α = 0.849). ΔHU values were compared across histopathological groups (malignant, necrotic, inflammatory), and diagnostic performance was assessed using receiver operating characteristic (ROC) analysis.
Results:
Malignant lesions demonstrated higher attenuation values pre-biopsy (median 32 [interquartile range (IQR) 25-40] HU) and post-biopsy (41 [35-49.25] HU) compared with necrotic (31.5 [24.5-35] HU and 25 [20-30] HU) and inflammatory lesions (27 [12-35] HU and 25 [12-37] HU), respectively (p < 0.001). ΔHU was positive in malignant lesions (10 [7-13] HU), negative in necrotic lesions (-3.5 [-6 to -1.25] HU), and minimal in inflammatory lesions (1 [-2 to 2] HU) (p < 0.001). ΔHU showed excellent discriminatory ability for malignancy (area under the curve [AUC] = 0.956), with a sensitivity of 94% and a specificity of 78%.
Conclusion:
ΔHU measurement during TCNB may serve as a quantitative biomarker with potential to differentiate malignant from necrotic or inflammatory thoracic lesions. Incorporating ΔHU may provide additional information that could enhance diagnostic confidence and guide biopsy targeting, although prospective studies are needed to confirm its impact on clinical decision-making.
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