1. Mesoscopic and Multilayers Structures Laboratory, Department of Physics, Faculty of Science, University of Dschang , P.O. Box 479, Dschang , Cameroon
2. Department of Radiography, Yaoundé General Hospital , Yaoundé , Cameroon
3. Department of Radiology, Bafoussam Regional Hospital , Bafoussam , Cameroon
4. Department of Radiology, National Social Insurance Fund Hospital , Yaoundé , Cameroon
5. Department of Radiology, Limbe Regional Hospital , Limbe , Cameroon
6. Department of Radiology, Yaoundé teaching Hospital , Yaoundé , Cameroon
7. Department of Radiology, Yaounde Gynaeco-Obstetric and Pediatric Hospital , Yaoundé , Cameroon
8. Department of Radiology, Douala General Hospital , Douala , Cameroon