Diffusion-Weighted Magnetic Resonance Imaging in Lung Cancer Evaluation

Diffusion-weighted magnetic resonance imaging (DW-MRI) has emerged as a non-invasive technique for characterising pulmonary lesions by probing the motion of water molecules within tissue. In lung cancer evaluation, DW-MRI offers quantitative biomarkers—most notably the apparent diffusion coefficient (ADC)—that correlate with tumour cellularity, microstructure and perfusion. Advanced models such as intravoxel incoherent motion (IVIM) separate true molecular diffusion from microvascular perfusion, while multi-b-value acquisitions enable derivation of parameters including the true diffusion coefficient (D), pseudo-diffusion coefficient (D*) and perfusion fraction (f). These metrics aid in distinguishing benign from malignant nodules, subtyping non-small-cell lung cancer (NSCLC) and small-cell lung cancer (SCLC), assessing tumour grade and predicting nodal involvement. Recent refinements in acquisition techniques—such as turbo spin echo and navigator-triggered single-shot echo-planar imaging—have improved geometrical accuracy and reduced artefacts from respiratory motion. Beyond diagnosis, DW-MRI is gaining traction as a tool to monitor early response to chemotherapy and to predict proliferative activity through correlations with proliferation markers. Its radiation-free nature, coupled with quantitative output, supports its integration into multiparametric protocols for personalised management of lung cancer.

Research from Nature Portfolio

Recent studies have demonstrated the feasibility and diagnostic performance of turbo spin echo–based DW-MRI for solitary pulmonary lesions. Multi-b-value acquisitions yielded ADC800, ADCtotal and IVIM-derived D values, all significantly lower in malignant than benign nodules. The D value achieved the highest area under the receiver operating characteristic curve, while lesion-to-spinal cord signal intensity ratio (LSR) provided complementary contrast measurement. Perfusion fraction (f) did not differ significantly between groups, indicating that molecular diffusion metrics drive discrimination. Foundational work on IVIM DWI further confirmed excellent inter-observer reproducibility for D and ADC maps, with malignant lesions showing consistently lower values than benign ones. In both instances, the D coefficient outperformed pseudo-diffusion (D*) and f in distinguishing malignant from benign pulmonary lesions, affirming the value of advanced diffusion modelling in clinical lung cancer evaluation.

Diffusion-Weighted Magnetic Resonance Imaging in Lung Cancer Evaluation publication trend

The graph below shows the total number of articles in diffusion-weighted magnetic resonance imaging in lung cancer evaluation across all publications each year (not limited to Nature Index journals).

Technical terms

Diffusion-weighted imaging (DWI): A magnetic resonance technique that sensitises images to the random Brownian motion of water molecules, revealing microstructural tissue properties.

Apparent diffusion coefficient (ADC): A quantitative measure of overall water diffusivity within a region of interest, inversely related to cellular density and membrane integrity.

Intravoxel incoherent motion (IVIM): A bi-exponential model that separates true molecular diffusion (D) from microvascular perfusion effects (D* and f) in diffusion data.

b value: The diffusion weighting factor in DWI sequences, expressed in s/mm², determining sensitivity to water motion; higher b values emphasise slower diffusion.

Perfusion fraction (f): In IVIM analysis, the proportion of signal attributed to microvascular blood flow within the diffusion measurement.

Pseudo-diffusion coefficient (D*): In IVIM, a parameter reflecting incoherent motion associated with capillary perfusion rather than true molecular diffusion.

Extracellular volume fraction (ECV): A metric derived from T1 mapping that estimates the proportion of extracellular space, used alongside diffusion parameters to characterise tissue microenvironment.

Lesion-to-spinal cord signal intensity ratio (LSR): A semi-quantitative index comparing lesion signal to spinal cord signal on diffusion maps, enhancing differentiation between benign and malignant tissue.

References

1. Predictors of lung cancer subtypes and lymph node status in non-small-cell lung cancer: intravoxel incoherent motion parameters and extracellular volume fraction. Insights into Imaging (2024).
2. Value of turbo spin echo–based diffusion-weighted imaging in the differential diagnosis of benign and malignant solitary pulmonary lesions. Scientific Reports (2024).
3. Effectiveness of Apparent Diffusion Coefficient Values in Predicting Pathologic Subtypes and Grade in Non-Small-Cell Lung Cancer. Diagnostics (2024).
4. Diagnostic performance of diffusion-weighted imaging versus 18F-FDG PET/CT in differentiating pulmonary lesions: an updated meta-analysis of comparative studies. BMC Medical Imaging (2023).
5. Relationship between Apparent Diffusion Coefficient and Tumour Cellularity in Lung Cancer. PLOS ONE (2014).
6. Intravoxel incoherent motion diffusion-weighted MR imaging in assessing and characterizing solitary pulmonary lesions. Scientific Reports (2017).
7. Diffusion‐weighted MRI of the lung at 3T evaluated using echo‐planar‐based and single‐shot turbo spin‐echo‐based acquisition techniques for radiotherapy applications. Journal of Applied Clinical Medical Physics (2018).
8. Prediction of Early Response to Chemotherapy in Lung Cancer by Using Diffusion‐Weighted MR Imaging. The Scientific World JOURNAL (2014).
9. A Noninvasive Assessment of Tumor Proliferation in Lung cancer Patients using Intravoxel Incoherent Motion Magnetic Resonance Imaging. Journal of Cancer (2021).