High-resolution computed tomography (HRCT) comparison of interstitial lung disease (ILD) patterns in systemic sclerosis (SSc). Figures A (axial) and B (coronal) display a Non-Specific Interstitial Pneumonia (NSIP) pattern characterized by bilateral, diffuse ground-glass opacities and mild traction bronchiectasis with a distinct basal predominance. Figures C (axial) and D (coronal) demonstrate a Usual Interstitial Pneumonia (UIP) pattern. This pattern is marked by extensive subpleural honeycombing (clusters of cystic airspaces), exuberant traction bronchiectasis, and severe architectural distortion predominantly involving the lower lung zones. These diagnostic images serve to illustrate the distinct radiologic morphology between NSIP and UIP patterns in patients with connective tissue disease-associated ILD, highlighting key features such as distribution, presence of honeycombing, and the degree of fibrotic changes essential for clinical classification and management.

High-resolution computed tomography (HRCT) of the chest in a patient with scleroderma-associated nonspecific interstitial pneumonia (NSIP). Image A (axial view) demonstrates bilateral ground-glass attenuation interspersed with fine linear reticular opacities. Hallmark signs of fibrotic lung disease, including traction bronchiectasis and bronchiolectasis, are visible within the areas of lung parenchyma distortion. A characteristic feature of NSIP—subpleural preservation—is indicated by an open arrow, showing a narrow band of relatively spared lung tissue immediately adjacent to the pleura. Image B (coronal reformatted view) highlights the classic symmetric and predominantly basal distribution of the interstitial changes, with opacities increasing in severity toward the lung bases. These findings collectively represent the common imaging presentation of cellular and fibrotic NSIP within the context of systemic autoimmune disease. This diagnostic imaging serves as a clinical reference for identifying patterns of interstitial lung disease and differentiating NSIP from other patterns such as usual interstitial pneumonia (UIP).

This composite educational resource consists of a diagnostic imaging panel (A) and a comparison bar chart (B) illustrating interstitial lung disease (ILD) patterns in patients with Sjögren's syndrome. Panel A displays axial High-Resolution Computed Tomography (HRCT) slices of four distinct ILD patterns: Usual Interstitial Pneumonia (UIP) characterized by peripheral reticulation and honeycombing; Non-Specific Interstitial Pneumonia (NSIP) showing more uniform ground-glass opacities; Desquamative Interstitial Pneumonia (DIP) with diffuse ground-glass attenuation; and Combined Pulmonary Fibrosis and Emphysema (CPFE) demonstrating upper-lobe emphysematous lucencies alongside fibrotic changes. Panel B is a horizontal bar chart quantifying the prevalence of these CT disease patterns among the study cohort. The chart indicates that UIP is the most frequent pattern, followed by NSIP, unspecific changes (Unspez), and lastly DIP and CPFE, which show equal, lower prevalence. This visual aid is intended for medical education regarding the radiologic classification and epidemiological distribution of pulmonary manifestations in systemic autoimmune diseases.

High-resolution computed tomography (HRCT) axial scan of the chest at the level of the lower lobes demonstrating parenchymal abnormalities. The image shows bilateral, predominantly peripheral, and basal patchy ground-glass opacities (GGO), appearing as areas of hazy increased lung attenuation that do not obscure the underlying pulmonary vasculature. Intermixed with the GGO is a fine reticular pattern, characterized by linear opacities representing interstitial thickening. While the biopsy confirmed Usual Interstitial Pneumonia (UIP), the HRCT lacks definitive features of a UIP pattern, such as honeycombing or significant traction bronchiectasis; instead, the diffuse, symmetric distribution and predominant GGO are more suggestive of a Nonspecific Interstitial Pneumonia (NSIP) pattern. This case serves as a clinical example of the discordance between radiologic patterns and histologic findings in interstitial lung disease (ILD), highlighting the importance of multidisciplinary diagnosis.

This composite diagnostic image features four axial High-Resolution Computed Tomography (HRCT) scans of the lung bases, illustrating various manifestations of Interstitial Lung Disease (ILD) commonly associated with Systemic Sclerosis (SSc).

This composite of four axial high-resolution computed tomography (HRCT) scans illustrates various radiologic patterns of Rheumatoid Arthritis-associated Interstitial Lung Disease (RA-ILD). Panel A demonstrates a Usual Interstitial Pneumonia (UIP) pattern, characterized by bibasilar, subpleural honeycombing (clusters of cystic airspaces), reticular opacities, and traction bronchiectasis. Panel B displays a Nonspecific Interstitial Pneumonia (NSIP) pattern, showing diffuse, patchy ground-glass opacities and septal thickening with relative subpleural sparing. Panel C reveals a Lymphocytic Interstitial Pneumonia (LIP) pattern, highlighted by perivascular thin-walled lung cysts (indicated by black arrows). Panel D illustrates an Organizing Pneumonia (OP) pattern, featuring focal areas of parenchymal consolidation (indicated by a white arrow). These images serve as educational benchmarks for differentiating pulmonary manifestations in systemic autoimmune diseases. The radiological findings are critical for determining prognosis and guiding therapeutic strategies, such as distinguishing between predominantly fibrotic (UIP) versus inflammatory (NSIP/OP) processes.

**Imaging Modality:** High-resolution computed tomography (HRCT) of the chest, axial section.

**Imaging Modality:** High-Resolution Computed Tomography (HRCT) of the chest.

Two axial slices of high-resolution computed tomography (HRCT) of the chest demonstrating a classic Usual Interstitial Pneumonia (UIP) pattern. The images show significant bilateral lung parenchymal abnormalities with a subpleural and basal predominance. Key radiologic features include extensive honeycombing, characterized by clustered, thick-walled subpleural cystic airspaces, and prominent reticular opacities. Additionally, there is evidence of traction bronchiectasis, where the fibrotic destruction of the lung architecture has caused irregular dilation of the bronchi. These findings are consistent with end-stage pulmonary fibrosis, often seen in idiopathic pulmonary fibrosis or connective tissue disease-associated interstitial lung disease (such as systemic sclerosis). The images serve as an educational example of advanced architectural distortion and the characteristic distribution of UIP-pattern fibrosis, distinguishing it from other interstitial lung diseases by the presence of honeycombing and peripheral gradient.