Minimum intensity projection (MinIP)
Minimum intensity projection (MinIP) is a data visualization method that enables detection of low-density structures in a given volume. The algorithm uses all the data in a volume of interest to generate a single bidimensional image, in other words, its consists of projecting the voxel with the lowest attenuation value on every view throughout the volume onto a 2D image 1,3.
The MinIP algorithm is almost identical to the MIP algorithm but, in the case of MinIP, for each XY coordinate, only the lowest Hounsfield value along the Z axis is represented. In this way, only the most hypodense structures of the volume are represented 1.
So it is the optimal tool for the detection, localization, and quantification of ground-glass and linear attenuation patterns on chest scans 3.
The MinIP algorithm is particularly useful for analyzing the bile tree and pancreatic duct, which are hypodense compared to surrounding tissue, especially in the pancreatic and portal phase of contrast agent administration 2.
- 1. Perandini S, Faccioli N, Zaccarella A, Re TJ, Mucelli RP. The diagnostic contribution of CT volumetric rendering techniques in routine practice. Indian J Radiol Imaging [serial online] 2010 [cited 2011 Aug 28];20:92-7. Available from: http://www.ijri.org/text.asp?2010/20/2/92/63043
- 2. Rao ND, Gulati MS, Paul SB et-al. Three-dimensional helical computed tomography cholangiography with minimum intensity projection in gallbladder carcinoma patients with obstructive jaundice: comparison with magnetic resonance cholangiography and percutaneous transhepatic cholangiography. J. Gastroenterol. Hepatol. 2005;20 (2): 304-8. doi:10.1111/j.1440-1746.2004.03548.x - Pubmed citation
- 3. Cody DD. AAPM/RSNA physics tutorial for residents: topics in CT. Image processing in CT. Radiographics. 22 (5): 1255-68. Radiographics (full text) - Pubmed citation