Diffusion-weighted Imaging of the Chest: A Primer for Radiologists

Area of Science:

• Magnetic Resonance Imaging
• Oncologic Imaging
• Thoracic Imaging

Background:

• Diffusion-weighted imaging (DWI) is crucial in neuroimaging and oncology.
• Emerging applications of DWI in thoracic MRI are expanding its utility.
• DWI provides functional information beyond spatial resolution, measuring diffusion at the micrometer scale.

Purpose of the Study:

• To highlight the role and optimization of DWI in thoracic MRI.
• To demonstrate DWI's capability in enhancing lesion conspicuity and characterization.
• To compare DWI's advantages over PET/CT in thoracic cancer assessment.

Main Methods:

• Optimization of DWI acquisition parameters including b values, parallel imaging, fat saturation, and motion correction.
• Evaluation of DWI signal attenuation and apparent diffusion coefficient (ADC) maps for tissue characterization.
• Assessment of morphologic and other functional MRI features alongside DWI.

Main Results:

• DWI improves detection of pulmonary, mediastinal, and pleural lesions with excellent contrast-to-noise ratio.
• DWI aids in characterizing cystic lesions and classifying chest lesions as benign or malignant.
• DWI shows advantages over 18F-FDG PET/CT in lung cancer assessment, staging, and treatment monitoring.

Conclusions:

• DWI is a valuable, noninvasive, quantitative, and reproducible tool for thoracic MRI.
• Careful parameter optimization is essential for effective DWI implementation in chest imaging.
• DWI offers significant benefits for the evaluation and management of thoracic neoplasms.