Radiology, Vol 169, 55-58, Copyright © 1988 by Radiological Society of North America
Mach bands in mammography
WH Gordenne and FL Malchair
Service de Radiodiagnostic, Hopital de Baviere, Universite de Liege, Belgium.
The radiologic appearance of tissue surrounding a tumor often influences
the characterization of a cancerous lesion. An example is the radiolucent
halo that is sometimes seen around breast cancers. Mammograms of 108
malignant tumors (74 scirrhous tumors, 17 partially scirrhous nodular
tumors, and 17 nodular tumors) and eight benign tumors that showed
peritumoral fat were retrospectively evaluated. All the scirrhous and
partially scirrhous nodular cancers were more or less surrounded by a
5-10-mm-wide hyperlucent halo; this corona sign was also found in 14
nodular cancers. The halo sign, a hyperleucent 1-mm band, was observed
around all benign lesions and immediately adjacent to sharply delineated
cancers. These radiologic findings are an optical illusion (Mach band,
background contrast effect). Densitometric measures and isoluminous
analysis did not demonstrate the presence of a true hyperlucent zone.
