HRCT chest: prone images

Prone high-resolution CT (HRCT) imaging corresponds to an additional CT acquisition performed as part of the HRCT chest protocol. It represents a scan performed with the patient on prone position and images obtained in full inspiration. 

This additional imaging is particularly useful for detecting subtle or early interstitial lung disease (ILD). The rationality behind it is to differentiate dependent lung atelectasis, which commonly presents as subpleural densities or lines, from early ILD. 


Some institutions make it routinely acquired in every initial chest HRCT assessment; others perform a routine radiologist imaging review with the patient still on the table to determine if a prone scan is necessary. 

Patients with unknown or early ILD are the ones that most benefit from it. When there is advanced ILD, dependent opacities are unlikely to pose a diagnostic dilemma and, therefore, additional prone images are of uncertain relevance. 


  • sequential spaced is prefered over a volumetric acquisition in view of a reduction in the radiation dose the patient is exposed
  • gap of 2-4 cm between two sets of images
  • no intravenous contrast is required
  • postprocessing: high-spatial-frequency or sharpening algorithm (bone algorithm)
CT examinations
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Article information

rID: 68144
System: Chest
Tag: refs
Synonyms or Alternate Spellings:
  • HRCT chest on prone

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