TITLE:
Removal of the Shadow of Cervical Vertebrae from Panoramic X-Ray Images with a Tomosynthesis Method
AUTHORS:
Koichi Ogawa, Jyunpei Yamamoto, Masatoshi Yanase, Akitoshi Katsumata
KEYWORDS:
Panoramic; Radiography; Cervical Vertebrae; Subtraction Technique
JOURNAL NAME:
Open Journal of Medical Imaging,
Vol.3 No.4,
December
20,
2013
ABSTRACT: The purpose of this study is to
remove the shadow of cervical vertebrae from dental panoramic x-ray images with
a tomosynthesis
method and improve the contrast of details in both the teeth and jaw bones. To
measure the shift-amount at each angular position that was required for
reconstruction of panoramic x-ray images of the dental arch, strip images of a
calibration phantom were acquired. Then, a shift-amount table was prepared from
these images, and the other shift-amount table, which was used to reconstruct a panoramic image of the
cervical vertebrae, was prepared by inverting the curve of the shift-amount
table upside down. Using these two tables, images focused on the dental arch
and cervical vertebrae of a patient were made with the original strip data of
the patient. The shadow of the cervical vertebrae appearing on the image focused on
the dental arch was removed using the two above-mentioned images and blurring
functions defined at two focusing geometries. The validity of the proposed
method was evaluated with clinically acquired data of two patients. The
shadow of the cervical vertebrae was successfully eliminated, and the contrast
of the front teeth and detailed structures of the jaw bones was improved. The
results of the experiments showed that our proposed method was significantly
effective in removing the shadow of the cervical vertebrae from conventional
panoramic x-ray
images.