# 3D Nodule Viewer Interactive 3D models of pulmonary nodules, viewable in augmented reality at true real-world scale. Each morphology is rendered at four diameters — 4 mm, 10 mm, 20 mm, and 30 mm — so the number in a radiology report becomes a physical object you can look at. Models are delivered as GLB for WebGL rendering in the browser and USDZ for AR Quick Look on iOS. AR placement uses WebXR on Android and AR Quick Look on iOS Safari, and all models are rendered at 1:1 real-world scale in AR mode. ## Smooth Solid *Well-defined, uniform border. Density: solid. Margin: smooth.* A solid nodule with a smooth, well-defined border. Smooth margins are generally associated with lower malignancy suspicion, though size and density remain important factors. **Clinical note:** smooth margins suggest the nodule edge is distinct with no irregularity. While reassuring, all nodules require appropriate follow-up per guidelines. *Source: MacMahon et al., Fleischner Society Guidelines. Radiology 2017; ACR Lung-RADS 2022.* ## Lobulated *Scalloped, multi-lobed border. Density: solid. Margin: lobulated.* A solid nodule with a lobulated — or scalloped — border, created by uneven tumour growth rates at different points along the margin. The bumpy, multi-lobed outline reflects variability in how aggressively different parts of the nodule are expanding. **Clinical note:** lobulated margins carry an intermediate-to-higher level of malignancy suspicion compared with smooth borders. They are associated with uneven cell proliferation and warrant careful size and growth monitoring per Fleischner Society guidelines. *Source: MacMahon et al., Fleischner Society Guidelines. Radiology 2017; ACR Lung-RADS 2022.* ## Spiculated *Irregular, spike-like projections. Density: solid. Margin: spiculated.* A solid nodule with irregular, spike-like projections radiating outward from its surface. Spiculation occurs when tumour cells infiltrate and distort the surrounding lung tissue, pulling it inward and creating the characteristic star-burst appearance. **Clinical note:** spiculated margins are one of the strongest imaging predictors of malignancy. They are associated with invasive tumour growth and are weighted heavily in both the Mayo Clinic risk model and Lung-RADS classification. Biopsy or early resection is typically warranted. *Source: Swensen et al., Arch Intern Med 1997; MacMahon et al., Radiology 2017; ACR Lung-RADS 2022.* ## Ground Glass *Hazy, semi-transparent opacity. Density: ground glass. Margin: ill-defined.* A ground-glass opacity (GGO) nodule appears as a hazy, cloud-like area on CT — semi-transparent, with indistinct borders that fade rather than cut sharply. Unlike solid nodules, the underlying lung structures remain partially visible through it. **Clinical note:** pure GGO nodules have a higher rate of indolent adenocarcinoma in situ. They require longer follow-up intervals than solid nodules of the same size. Per Fleischner Society guidelines, pure GGOs of 6 mm or less typically require no routine follow-up. *AR is unavailable for this model: USDZ / AR Quick Look does not support the alpha-blend transparency the ground-glass material relies on.* *Source: Naidich et al., Radiology 2013; MacMahon et al., Radiology 2017; ACR Lung-RADS 2022.* ## Part-Solid *Mixed solid and ground glass. Density: part-solid. Margin: ill-defined.* A part-solid nodule has two components: a solid core of denser tissue surrounded by a hazy ground-glass opacity halo. The solid portion reflects areas of more advanced or invasive growth, while the ground-glass halo represents less dense, early-stage involvement. **Clinical note:** part-solid nodules carry the highest malignancy risk of all nodule subtypes. The solid component size drives management decisions — solid components of 6 mm or more warrant PET-CT or tissue sampling per Fleischner Society guidelines. *AR is unavailable for this model, for the same transparency reason as ground glass.* *Source: MacMahon et al., Fleischner Society Guidelines. Radiology 2017; ACR Lung-RADS 2022.* ## Compare — nodule sizes against everyday objects A comparison mode that places a nodule beside a familiar object at true relative scale. **4 mm — versus a grain of rice.** A typical grain of rice measures about 5 mm in length, meaning a 4 mm nodule is smaller than something you can barely see when it falls on the counter. At 4 mm this nodule is below the Fleischner Society action threshold for average-risk patients; pure solid nodules under 6 mm typically require no routine follow-up CT. **10 mm — versus a piece of cereal.** A standard cereal ring measures approximately 11.5 mm in diameter. At 10 mm the nodule falls into the intermediate size range; per Fleischner Society guidelines, solid nodules of 6 mm or more in average-risk patients warrant follow-up CT at 6–12 months. **20 mm — versus a US penny.** A penny measures 19.05 mm in diameter, nearly identical to this nodule. At 20 mm the nodule exceeds the Fleischner Society threshold requiring prompt workup; solid nodules of 15 mm or more warrant PET-CT or tissue sampling regardless of risk factors. **30 mm — versus a golf ball.** A golf ball measures 42.67 mm in diameter. At 30 mm the nodule exceeds the Fleischner Society threshold for high malignancy suspicion; nodules this size typically warrant PET-CT, tissue sampling, or surgical evaluation. ## Methodology 3D nodule models are created in Blender and rendered with Google's `model-viewer` web component. They are stylised representations for educational visualisation — not derived from patient imaging data, and not representing any specific radiological finding. The teal colouring is the app's design theme, not actual nodule appearance; on CT imaging, pulmonary nodules appear as white or grey opacities against dark lung tissue. Third-party reference models used in the comparison scenes are credited individually on the [references page](https://nodule.app/references). ## Related - [Nodule Types](https://nodule.app/tutorial) — what each morphology means clinically. - [Risk calculator](https://nodule.app/calculator) — how diameter and spiculation feed the Mayo Clinic model. --- *Educational use only · Not a medical device.* This document mirrors the page at .