cone beam international magazine of cone beam dentistry

42 I I user report _ CBCT in cervical spondylosis diagnosis _Introduction Cone beam computed tomography (CBCT) has been conventionally used to diagnose diseases of the maxillofacial area for many decades. In the past fewyearssinonasalimagingwithCBCThasbecome popular due to its low radiation dosage. The field of CBCT has received a great deal of R&D attention and consequently, technological progress has been fast and innovations frequent. As a result, the next appropriate area of CBCT imaging seems to be the area of cervical spine ranging from the level of occiput till the level of C7. Due to the drastic in- crease of patients with cervical spondylosis and newoperativetechniques of spondylodesis the need for CT of the cervical spine has significantly increased. Compared to multidetector computed tomography (MDCT) of cervical spine the radia- tion dose of CBCT of cer- vical spine is considerably lower (i.e., comparable to AP and lateral views of cervical spine X-ray), but with much more detailed information of the spinal cavity and intervertebral foramina. The extent of false-positive diagnosis of intervertebral forami- nal narrowing is depend- ent on the positioning of the patient in oblique views of the cervical spine. With CBCT of cer- vical spine this can be avoided. Indications for a CBCT of the cervical spine are as follows: _cervical spine spondylosis leading to spinal ste- nosis; _facet joint arthrosis and associated dislocations; _inter-vertebral foraminal stenosis; _postoperative analysis of the anterior spondy- lodesis operations; _traumatic fractures; _bony tumours and associated destructions. _SCANORA 3D CBCT system SCANORA 3D (SOREDEX, Finland) system is a cone beam CT imaging system that is intended for the head and neck area. The unit has been in use at Röntgentutka private clinic in Tampere, Finland, for several years mainly for maxillofacial and sinus diagnostics. Recently the system has been used also for upper cervical spine examinations and has been found extremely useful. The fields-of-view (H x D) of the unit are 60 x 60mm,75x100mm,75x145mmand130x145mm, and they are selectable according to the diagnostic taskathand.SCANORA3Dprovidesaseatedpatient platform and the region of interest can be freely lo- catedintheheadandneckareathankstomotorized movements and laser lights. The voxel sizes for ad- justing the spatial resolution are selectable in the rangeof133–350µm.Theprotocolcanbeoptimized for each diagnostic task to produce proper image quality at minimum radiation dose. The cervical spine can be scanned starting at levelocciputtillC7.Thefieldofviewis130–145mm. Thevoxelsizeis0.3mm,andtheamountofradiation dose can be lower than recommended for example of that of the head and neck area. With CBCT this area can be well demonstrated depending on the patientanatomy:insevereobesitycasesthelevelof C7/T1 could be difficult to demonstrate without technical innovations. At SCANORA 3D the patient is stabile in anatomically optimal sitting position and the mandible is in a comfortable, optimal position resting on a plastic stand. In contrast, with MDCT scanning the patient is in a lying position, which changes the physiological position of the cervical spine. cone beam1_2014 Fig. 2 Use of CBCTin the diagnosis of cervical spine spondylosis Authors_Drs Jorma Järnstedt & Prasun Dastidar, Finland Fig. 1 CBE0114_42-43_Soredex 31.01.14 15:54 Seite 1