skip

HRCT Technique

HRCT  Technique

Principle of MIP and MINIP Reconstructions

One of the optional conditions for conducting a chest CT of usual
interstitial pneumonia is reconstructing images using maximum intensity
projection (MIP) and minimal intensity projection (minIP) algorithms1.

These reconstructions are used to obtain information that is not always
visible on the axial cross-sections but which is useful for diagnosis1.

These two reconstructions are based on the same principle:

  • acquisition of volumetric CT  in mm-thick cross-sections

  • selection of the desired orientation and thickness of the cross sections,
    namely 5-8 mm

  • application of the MIP or minIP algorithm based on clinical needs
    regarding selected volume:

    • MIP select the densest voxels* in the selection in order to better detect dense anomalies in the lungs (for example, micronodules)

    • minIP select the least dense voxels* in the selection in order to better detect hypodense anomalies in the lungs (for example, cysts, emphysema, or bronchiectasis)

MIP (Maximum Intensity Projection)1

MIP 1mm
MIP 5mm

Application of the MIP algorithm on
1-mm and 5-mm cross-section from a
patient with suspected micronodulation.
The 5-mm MIP can bring together
the micronodules in the 5-mm
thickness, making it possible to confirm
micronodulation and identify their
topography within the lobule.

MINIP (Minimal Intensity Projection)1

Minip 1mm
Minip 2,5mm
Minip 5mm

Application of the minIP algorithm to variable thicknesses of cross-sections between 1 and 5 mm. The minIP allows to see the air contained in the scanned area. Traction bronchiectases are therefore more visible in the minIP 5 mm CT within the ground-glass opacity.

References

References

  1. Collège des Enseignants de Pneumologie. Item 206 (ex item 120). Pneumopathies interstitielles diffuses. 2013

  2. Cottin V, et al. French practical guidelines for the diagnosis and management of idiopathic pulmonary fibrosis - 2017 update. Full-length version. Rev Mal Respir 2017;34:900-68

  3. Brauner M, et al. Imagerie des pneumopathies diffuses. Press Med 2010 39: 73-84

  4. Raghu G, et al. Diagnosis of Idiopathic Pulmonary Fibrosis. An Official ATS/ERS/JRS/ALAT Clinical Practice Guideline. Am J Respir Crit Care Med 2018;198:e44-e68