This diagnostic image is an axial non-contrast-enhanced CT scan of the chest at the level of the upper lobes, demonstrating significant chronic obstructive pulmonary disease (COPD) pathology. The lung parenchyma shows extensive centrilobular emphysema, characterized by multiple small, focal areas of low attenuation representing alveolar destruction within the secondary pulmonary lobules. Complementary paraseptal emphysematous changes are visible as subpleural lucencies along the peripheral lung margins. In the apicoposterior segment of the left upper lobe, there is a localized area of increased attenuation consistent with a fibrotic lesion or reticular opacity. The distribution is primarily bilateral and upper-lobe predominant, which is characteristic of smoking-related lung disease. Key educational concepts include the radiographic differentiation between centrilobular and paraseptal emphysema and the identification of concurrent interstitial lung changes in a patient with multi-faceted parenchymal disease.

Two axial CT pulmonary angiography (CTPA) slices displayed in a lung window, illustrating chronic obstructive pulmonary disease (COPD) pathology. Image (a) shows a large, well-circumscribed, air-filled bulla in the right apical region, indicated by a red arrow. This bulla causes focal compression of the adjacent lung tissue and significant rarefaction of the vascular markings. Image (b) shows a lower thoracic section demonstrating diffuse, bilateral emphysematous changes. The lung parenchyma exhibits increased lucency, multiple small air-filled lucent spaces, and a reduction in the density and caliber of peripheral pulmonary vessels, creating a 'spongy' texture. These findings are characteristic of extensive centrilobular and paraseptal emphysema. The images provide clinical evidence of severe parenchymal destruction, contributing to decreased gas exchange and potential secondary pulmonary hypertension.

This Comparison Chart features two axial non-contrast Computed Tomography (CT) scans of the thorax at the level of the main pulmonary artery, illustrating different phenotypes of Stage 2 Chronic Obstructive Pulmonary Disease (COPD). The left panel displays a patient with relatively preserved lung parenchyma, characterized by normal attenuation and intact vascular markings without visible emphysematous destruction. The right panel demonstrates advanced structural pathology in a second patient, showcasing significant centrilobular and paraseptal emphysema. Red arrows highlight multiple pulmonary bullae, appearing as focal areas of low attenuation (increased lucency) with thin, well-defined walls, representing localized tissue destruction. A diffuse reduction in vascular density is also evident in the emphysematous lung compared to the normal scan. The educational focus is the radiological manifestation of COPD phenotypes, specifically the correlation between parenchymal destruction, anatomical deadspace volume, and lung inhomogeneity as visualized through diagnostic imaging.

This image shows gastric body mucosa obtained by biopsy, examined under light microscopy with standard Hematoxylin and Eosin staining. The histologic hallmark is marked foveolar hyperplasia with elongated, tortuous glands and frequent cystic dilatation of mucous glands, a pattern strongly suggestive of hypertrophic gastropathy. The surface epithelium is mucin-rich, with tall, columnar foveolar cells forming crowded, branching pits; deep oxyntic glands are variably atrophic in affected foci. Lamina propria is mildly edematous and may contain modest chronic inflammatory infiltrates. The overall architecture is diffuse rather than polypoid, consistent with a non-neoplastic, hyperplastic process. No definite dysplasia is observed in this field; however, Menetrier-type hypertrophic gastritis (Menetrier disease) carries a recognized risk of gastric adenocarcinoma with time. The pattern correlates clinically with adult-onset, often severe disease characterized by diffuse thickening of the gastric folds and protein-losing enteropathy, whereas pediatric forms are typically self-limited. On this section, the combination of foveolar hyperplasia, gland tortuosity, and cystic dilation constitutes the diagnostic clue. This histology supports a diagnosis of Menetrier-type hypertrophic gastropathy and has implications for management, including monitoring for nutritional deficiency, edema, and potential neoplastic transformation, and consideration of EGFR-targeted therapies in selected patients.

Brightfield hematoxylin and eosin (H&E) stained histology of the gallbladder neck and cystic duct region. Peribiliary mucous glands form a characteristic lobular architecture with evenly spaced, uniform tubules embedded in the fibromuscular lamina propria. The glands are lined by cuboidal to low-columnar mucinous epithelium with minimal cytologic atypia, mild cytoplasm, and rare mitotic figures. The glands lie in close proximity to the biliary epithelium but remain within the peribiliary/submucosal compartment, without evidence of stromal invasion or desmoplastic reaction. This benign pattern can be mistaken for invasive adenocarcinoma if the glands are sampled in a disorganized fashion or show crowding near the gallbladder neck. In contrast, invasive carcinoma glands are typically haphazardly scattered, infiltrative, and accompanied by cytologic atypia, desmoplasia, and irregular nuclear features. The image highlights orderly glandular lobules, uniform tubules, and lack of cytologic atypia, supporting a benign peribiliary gland process. Clinically, recognizing this pattern is essential to avoid overtreatment, especially in limited biopsy samples. Correlation with gross anatomy and imaging, and, when needed, ancillary stains or immunohistochemistry can help distinguish benign peribiliary gland hyperplasia from biliary adenocarcinoma. This distinction influences prognosis and therapeutic planning. Appropriate sampling and awareness reduce false positives in needle biopsies and guide management decisions.

Educational comparison of Chronic Obstructive Pulmonary Disease (COPD) phenotypes using diagnostic imaging and quantitative data. Panels A-B and D-E display coronal CT scans with color-coded overlays representing lung density; blue areas indicate low-attenuation areas (LAA) characteristic of centrilobular emphysema. Case 1 (A-C) shows upper-lung-dominant emphysema during inspiration (A) and expiration (B), where lower lung volume decreases significantly more than upper volume. Case 2 (D-F) demonstrates nearly equal volume reduction in both lung zones during expiration (E). Adjacent tables (C and F) provide Quantitative Lung sound Distribution (QLD) values for upper, middle, and lower regions of the right and left lungs. The visual demonstrates the relationship between anatomical emphysema distribution (upper-lung dominant), dynamic hyperinflation (evidenced by volume changes on expiration CT), and functional lung sound intensity. This illustrates how differing mechanical properties of emphysematous lungs affect air distribution and acoustic findings, useful for differentiating COPD severity and phenotypes.

This diagnostic image series presents four coronal chest CT scans illustrating emphysema quantification in patients with varying severity of Chronic Obstructive Pulmonary Disease (COPD). The quantification is based on the RA950 metric (relative area of CT density histogram voxels < -950 HU), which identifies Low Attenuation Areas (LAA) characteristic of emphysematous tissue. A color-coded overlay is used to differentiate tissue types: healthy lung parenchyma is represented in blue, while emphysematous regions are highlighted in purple. The four panels (labeled Q1 through Q4) demonstrate a progressive increase in LAA percentage, ranging from 7.3% in early-stage disease to 44.7% in advanced emphysema. Visually, the purple areas transition from sparse focal distributions in Q1 to widespread, confluent regions in Q4, often appearing more prominent in the upper lung zones. Central mediastinal and hilar structures are visible, with some orange/red markers indicating vascular or hilar regions. This comparison chart serves as an educational tool for understanding radiological progression and automated volumetric quantification of lung destruction in COPD patients.

This diagnostic image set displays a comparison between standard high-resolution computed tomography (CT) and Artificial Intelligence Quantitative CT (AIQCT) in a 68-year-old male patient with Chronic Obstructive Pulmonary Disease (COPD) and Interstitial Lung Abnormalities (ILAs). The layout includes axial (a, b) and sagittal (c, d) views. Figures 2a and 2c show conventional CT imaging with visible peripheral reticulations, subpleural honeycombing, and areas of increased opacity. Figures 2b and 2d feature AIQCT overlays that provide automated segmentation and color-coded identification of pulmonary features. According to the included legend, colors represent: red for honeycombing, blue for ground-glass opacity, yellow for hyperlucency (emphysema), pink for consolidation, and dark blue for reticulation. The AIQCT visualization demonstrates a heterogeneous distribution of disease, with hyperlucency predominantly in the upper lobes and fibrotic changes (honeycombing and ground-glass opacities) localized to the lung bases. This tool illustrates the objective quantification of Interstitial Lung Disease (ILD) volume (calculated at 150 mL or 2.90% in this case) for clinical monitoring.