Describing Diffuse Hazy Attenuation Without Subpleural Sparing
Describe this finding as "diffuse ground-glass attenuation" or "diffuse ground-glass opacity (GGO)" with specific notation that there is "no subpleural sparing" or "involvement extends to the pleural surfaces." This terminology is standardized and immediately conveys the pattern to radiologists and clinicians 1, 2.
Core Descriptive Framework
Ground-glass attenuation/opacity is defined as a diffuse homogeneous increase in lung density where bronchial and vascular margins remain visible 1, 2. This distinguishes it from consolidation, where these structures become obscured 2, 3.
When documenting your findings, structure the description as follows:
- Pattern: "Diffuse ground-glass attenuation" or "diffuse hazy increased attenuation"
- Distribution: "Bilateral and diffuse" with "no subpleural sparing"
- Associated findings: Note whether vessels appear normal, enlarged, or compressed within the affected areas 3
Critical Distinction: Vascular vs. Infiltrative Disease
Since you suspect vascular congestion, carefully assess the pulmonary vessel caliber within the areas of ground-glass attenuation 3. This is the key differentiating feature:
Vascular congestion/edema shows:
- Increased vessel diameter in affected areas
- Smooth interlobular septal thickening (if present)
- Central and peripheral distribution without true subpleural sparing
- Associated findings: enlarged pulmonary arteries (MPA >29mm), cardiomegaly, pleural effusions 4, 3
Infiltrative lung disease shows:
- Normal or decreased vessel caliber in affected areas
- May have centrilobular nodules, reticulation, or architectural distortion
- Variable distribution patterns 1, 5, 3
Specific Terminology for Your Report
Use this exact phrasing: "Diffuse bilateral ground-glass attenuation extending to the pleural surfaces without subpleural sparing, with [normal/increased/decreased] caliber of pulmonary vessels within affected regions, consistent with [vascular congestion/pulmonary edema]" 2, 3.
The absence of subpleural sparing is clinically significant because it helps exclude certain diagnoses. Subpleural sparing is characteristic of nonspecific interstitial pneumonitis (NSIP) and helps distinguish it from usual interstitial pneumonitis 6. When absent, as in your case, it broadens the differential toward processes that affect the entire lung uniformly, including vascular congestion, acute lung injury, or certain diffuse infiltrative processes 1, 5.
Additional Descriptors to Include
Document these features to strengthen diagnostic confidence:
- Vessel analysis: "Pulmonary vessels appear [prominent/normal] within areas of ground-glass attenuation" 3
- Septal thickening: If present, note whether it's smooth (favors edema) or irregular (favors fibrosis) 1
- Air bronchograms: Presence suggests alveolar filling rather than pure interstitial process 7
- Mosaic attenuation: Absence of this finding helps exclude small airway disease 5
Common Pitfalls to Avoid
Do not use "mosaic attenuation" to describe uniform ground-glass opacity. Mosaic attenuation specifically refers to a patchwork of areas with different attenuation levels, typically seen in hypersensitivity pneumonitis or small airway disease 5. Your description of diffuse hazy attenuation without this patchwork pattern is distinctly different.
Do not confuse ground-glass opacity with consolidation. If you can still see vessel margins, it's ground-glass opacity; if vessels are obscured, it's consolidation 2, 8.
The lack of subpleural sparing combined with preserved vessel visibility and clinical suspicion of vascular congestion creates a specific pattern that should prompt evaluation for cardiac causes, fluid overload, or pulmonary veno-occlusive disease 4.