🔍 HRCT Teaching Case: Perilobular Pattern in Organizing Pneumonia (OP)
This 63-year-old female patient shows a classic perilobular pattern—a distinct but underrecognized HRCT sign of OP.
🖼️ Slide: 9 HRCT patterns of OP
📸 Diagram 1: Perilobular consolidation vs perilobular GGO vs interlobular septal thickening (at lobular level)
📸 Diagram 2: Right lung: perilobular consolidation | Left: perilobular GGO
📹 Video of the patient’s HRCT
✅ Definition:
The perilobular pattern refers to consolidation or ground-glass opacity involving the inner aspects of interlobular septa, causing polygonal or arc-like opacities that outline lobular borders while sparing the central portion.
🧠 This results in a thicker, more irregular opacity than simple septal thickening (e.g., in interstitial pulmonary edema).
✅ Key Teaching Point:
In the right clinical setting, this pattern is diagnostic of organizing pneumonia.
No other ILD presents with a purely perilobular pattern—but only those familiar with this sign will recognize it on HRCT.
Once you know what to look for, it’s diagnostic at a glance.
#Radiology #HRCT #ChestImaging #ILD #OrganizingPneumonia #Pulmonology #MedicalEducation