Influence of small, midi, medium and large fields of view on accuracy of linear measurements in cbct imaging : Diagnostic accuracy study / Wessam Mohamed Magdi Ali ; Supervised Nashwa Salah Mohamed , Enas Anter Abdalghaffar , Hanaa Mohamed Alshenawy

Thesis (Ph.D.) - Cairo University - Faculty of Oral and Dental Medicine - Department of Oral (Radiology and Diagnosis)

This study aimed to evaluate the accuracy of CBCT linear measurements in different FOVs (Small, Midi, Medium and Large). This study was performed on thirteen implant bone models. On each model, at the incisors region three positions were selected, then on each of these positions three radio-opaque markers (gutta-percha pieces) were glued as; two pieces on the facial surface one occlusally and one apically, both were on the same vertical line and perpendicular to the horizontal plane, while the third one was placed on the lingual surface opposing the occlusally placed facial piece. Each sample was scanned with Cranex3Dx CBCT machine four times with four different FOVs and voxel sizes (Small: 50x50 mm with voxel size 200 æm, Midi: 61x78 mm with voxel size 300 æm, Medium: 78x78 mm with voxel size 300 æm and Large: 78x 150 mm with voxel size 350 æm). Distances between the GP pieces presented in height, thickness, and width of bone model were measured directly on the models by means of a digital caliper, and then compared with same distances measurements on CBCT images of these models obtained using distance measurement function of OnDemand3d viewer software

Issued also as CD