Cone-beam Technology Research Articles

Advancements in Computed Tomography Management of Chronic Rhinosinusitis

Advances in cone beam computed tomography (CBCT) technology have allowed for reduction in radiation dosages as well as the miniaturization of CT scanner units. This has given rise to new applications for CT scanning, including point-of-care (POC) in-office and intraoperative applications. A review of recent changes to radiological modalities as applied to otolaryngology-head and neck surgery was performed. A discussion of the physics, applications, and role of diagnostic imaging in the evaluation of chronic rhinosinusitis (CRS) is conducted. The adaptation of cone beam technology has allowed for the practical implementation of CT scanning at the bedside, be it in the clinic or operating room setting. Given their relative low cost, ease of storage, and low-dose radiation exposure, POC-CT scanners have become an indispensable tool in the diagnosis and treatment of CRS. In the setting of increasing antibiotic costs, overtreatment with antibiotics, and fewer required return visits, POC-CT challenges the conventional role of empiric medical therapy before progression to imaging for the diagnosis of CRS.

La Tomografia Computerizzata 3D nella diagnosi cefalometrica delle disgnazie dento-maxillo-facciali

ObjectivesThe aim of this work was to compare traditional radiographic cephalometry with that based on three-dimensional computed tomography (3D CT) and to evaluate the pros and cons of two different 3D CT methods. Materials and methodsTwo adult patients were examined with traditional radiographic methods and with two different tomographic techniques: fan beam CT and cone beam CT. The cephalograms obtained with these methods were analyzed with a traditional digital cephalometric approach and with 3D cephalometric software. Results and ConclusionsComputed Tomography provides more accurate information than traditional radiography since it eliminates the problems of deformation, magnifi cation, superimposition, and artifacts. It is especially useful in the presence of oral-maxillofacial dysgnathia since it allows study of the skull in each of the three dimensions. Cone beam technology uses a low dose of radiation and is less costly for patients and medical structures. With 3D cephalometric software, one can fully exploit the 3D data obtained with CT. It is especially valuable in the study of patients with maxillofacial asymmetry since the two sides of the face can be examined separately and then compared.

Assessing Validity of Actual Tooth Height and Width From Cone Beam Images of Cadavers With Subsequent Dissection to Aid Oral Surgery

Cone-beam computed technology (CBCT) is a relatively new medium for maxillofacial conditions. Developed in 1998, commercial cone beam technology has been commonly used since 2000. CBCT offers less radiation than computed tomography (CT) in 3D image construction. With the meteoric rise in the number of dental implant surgeries, CBCT could become a common machine in dental offices. The objective of this study is to validate the accuracy of CBCT tooth measurements. Twelve embalmed cadavers had a complete CBCT of the head and neck region. Ninety-six teeth (8 per cadaver) were extracted in total, but only 69 were collected and measured. CEN-TECH electronic calipers were used to measure the extracted teeth. iCAT measurements were used for imaged teeth. A literature search was conducted on the validity and use of CBCT regarding tooth measurements for implant surgery. Extracted teeth were measured in the vertical, facial to lingual, and mesial to distal dimensions. Exclusion factors included crown or root fracture damage during extraction. A literature search revealed studies that validated bone measurements using 14 different location points on the maxilla and 17 anatomical landmarks on the skull. Both studies validated bone measurements on CBCT. However, no studies were identified measuring teeth lengths for implant surgery. Three, two-tailed, paired t-test compared the iCAT image measurements to the extracted teeth measurements for each dimension. There was no statistical significance for each dimension. This study suggests using iCAT measurements on teeth from CBCT imaging would reflect the actual tooth length and could be beneficial for implant surgery.

Cone‐beam computed tomography of the maxillofacial region—an update

During the last few years, craniomaxillofacial diagnosis of the head has been confronted with an increasing number of innovations and improvements. The main progress occurred following the introduction of cone-beam technology in computed tomography in the 1990s. The number of manufacturers and devices using this technology for the maxillofacial region is growing rapidly and they are now becoming readily available. This article focuses on cone-beam computed tomography (CBCT) devices applied to the maxillofacial region. CBCT serves as a bridge from two dimensions (2D) to three dimensions (3D), with lower irradiation than conventional CT. Different manufacturers and models are now available to satisfy the different needs of clinicians. A recent review of the manufacturers found 23 CBCT devices on the market. The specifications, applications and other issues of currently available CBCT devices are presented and discussed. 3D imaging is developing at a very fast pace. New technologies and machines are emerging and CBCT is becoming readily available. Due to the growing demand for the technology based on the needs of clinicians, there is now a wide and growing selection of devices on the market. Some of the new advances now mean that CBCT imaging should be a well-considered option in maxillofacial imaging.

O.278 The role of cone beam CT in orthognathic surgery

Orthodontics has a commitment to precision and accuracy similar in concept to physical engineering. Both work in a 3-dimensional (3D) world—the engineer designing and modeling physical products, and the orthodontist diagnosing and treating patients. To achieve the best possible results, both fields have readily adopted and successfully implemented highly advanced mathematical techniques and sophisticated protocols. Today, a notable difference between the 2 fields relates to the data input and analysis/modeling tools that are now available. Technology advances in the past 5 years have started to erode these barriers to safely make human 3D data input as precise and easy to obtain as physical 3D object input. Many are familiar with the advances in 3D computed tomography, specifically cone-beam technology; this article focuses on a sister imaging technology called 3D surface imaging. These 3D systems enable extraoral imaging protocols to be equally precise in providing highly accurate 3D facial surface images for diagnosis, analysis, treatment monitoring, simulation, and outcome evaluation.

Implementing image-guided radiotherapy in the UK: plans for a co-ordinated UK research and development strategy

Image-guided radiotherapy (IGRT) is a relatively new technology designed to improve the accuracy of radiotherapy treatment. It is used to improve the assessment of patient position, particularly taking into account organ motion caused by respiration and physiological emptying and filling of internal organs. This in turn permits accurate radiation dose delivery, with the aim of improving tumour control and reducing side-effects. The National Radiotherapy Advisory Group and the Academic Clinical Oncology and Radiobiology Research Network (ACORRN) identified a need for a national strategy to improve research and development in this area. ACORRN was awarded funding from the National Cancer Research Institute (particularly Cancer Research UK) to organize a national conference to identify the current status and research opportunities of IGRT in UK radiotherapy departments. In order to ensure that the day was as useful and informative as possible, ACORRN carried out an initial national consultation via their website (www.acorrn.org) to determine the particular needs of the radiotherapy community from this conference. Consequently, an interactive programme was developed to provide information and discussion about (i) the technologies used, (ii) priority clinical questions and (iii) potential clinical trials being undertaken. Over 130 clinicians, physicists and radiographers — representing 61 UK institutions — attended the conference on 11 September 2006 in the Royal College of Physicians (London, UK). Professor Steve Webb and Dr Phil Evans (Royal Marsden Hospital NHS Trust, London) gave an overview of IGRT, focusing on current practice within the UK. Having defined IGRT as all radiotherapy techniques that rely on the use of threeor four-dimensional images, they went on to outline when it can be used, the technologies involved and the associated problems. Table 1 details current IGRT techniques and their availability in UK radiotherapy departments. It was noted that those techniques not yet widely used in the UK are all used clinically in other countries, and therefore funding to enable physicists, clinicians and radiographers to visit centres abroad where these techniques are well established would be extremely beneficial. The example in which IGRT techniques were introduced to aid the delivery of proton and ion beam radiotherapy was cited [1]. The validity of using other workers’ evidence, as opposed to carrying out local clinical trials, was also raised. The consensus was that a new trial would be unnecessary when a new or changed practice is evidently worth implementing, as happened with treatment planning. For complex issues, such as the use of functional imaging in radiotherapy or intensitymodulated radiotherapy (IMRT) vs non-IMRT, the range of variables means that trials are probably more appropriate, particularly with legal frameworks that dictate exposure justification. However, it was suggested that identification of a hierarchy of fundamental and important questions to be addressed would be useful in assessing at which point a trial needs to be considered. Dr David Nicholas (The Cromwell Hospital, London) and Professor Chris Moore (Christie Hospital NHS Trust, Manchester) discussed in detail the advantages and restrictions of tomotherapy [2] and cone beam technology [3–5], respectively. Indeed, the ‘‘pros’’ and ‘‘cons’’ of all available imaging methods were discussed throughout the meeting, particularly with respect to the dose required, image quality and cost, in terms of equipment, extra treatment time and availability of skilled personnel. To obtain an image, MV and kV portal and CT imaging require finite doses, ranging from 0.2 cGy to 15 cGy per imaging session, depending on the desired quality; Address correspondence to: Academic Clinical Oncology and Radiobiology Research Network, c/o Christie Hospital NHS Foundation Trust, Wilmslow Road, Manchester M20 4BX, UK. E-mail: acorrn@manchester.ac.uk The British Journal of Radiology, 81 (2008), 379–382

Completing the 3-dimensional picture

Orthodontics has a commitment to precision and accuracy similar in concept to physical engineering. Both work in a 3-dimensional (3D) world--the engineer designing and modeling physical products, and the orthodontist diagnosing and treating patients. To achieve the best possible results, both fields have readily adopted and successfully implemented highly advanced mathematical techniques and sophisticated protocols. Today, a notable difference between the 2 fields relates to the data input and analysis/modeling tools that are now available. Technology advances in the past 5 years have started to erode these barriers to safely make human 3D data input as precise and easy to obtain as physical 3D object input. Many are familiar with the advances in 3D computed tomography, specifically cone-beam technology; this article focuses on a sister imaging technology called 3D surface imaging. These 3D systems enable extraoral imaging protocols to be equally precise in providing highly accurate 3D facial surface images for diagnosis, analysis, treatment monitoring, simulation, and outcome evaluation.

Comparison of cone-beam volumetric imaging and combined plain radiographs for localization of the mandibular canal before removal of impacted lower third molars

The removal of third molars requires information about the relative position of the root tips and the mandibular nerve. The diagnostic value of conventional radiologic procedures using a panoramic radiograph and symmetrical PA cephalometric radiograph (PAN&PA) was compared with that of a cone-beam volumetric imaging (CBVI) device (Galileos; Sirona, Bensheim, Germany). Six observers evaluated 30 PAN&PA and 30 CBVI for the position of root tips. Diagnostic information was rated from 1 to 5 (excellent to poor). With PAN&PA, 3 times more scans showed nondetectable information for horizontal position compared with CBVI. The diagnostic information in the vertical dimension received a median rating of 2 (good) for CBVI and for PAN & PA; for the horizontal dimension, CBVI received a median rating of 2 (good), compared with a significantly worse median rating of 3 (sufficient) for PAN & PA (P = .000). The variance was highest for the horizontal dimension with PAN & PA (1.27). These findings indicate that cone-beam technology improves the localization of third molar for presurgical planning.

Endodontic Applications of Cone-Beam Volumetric Tomography

The ability to assess an area of interest in 3 dimensions might benefit both novice and experienced clinicians alike. High-resolution limited cone-beam volumetric tomography (CBVT) has been designed for dental applications. As opposed to sliced-image data of conventional computed tomography (CT) imaging, CBVT captures a cylindrical volume of data in one acquisition and thus offers distinct advantages over conventional medical CT. These advantages include increased accuracy, higher resolution, scan-time reduction, and dose reduction. Specific endodontic applications of CBVT are being identified as the technology becomes more prevalent. CBVT has great potential to become a valuable tool in the modern endodontic practice. The objectives of this article are to briefly review cone-beam technology and its advantages over medical CT and conventional radiography, to illustrate current and future clinical applications of cone-beam technology in endodontic practice, and to discuss medicolegal considerations pertaining to the acquisition and interpretation of 3-dimensional data.

Liability regarding computerized axial tomography scans

Recently, this question has come up repeatedly: What is the orthodontist’s liability for misreading or not fully reading in-office cone-beam computed-tomography (CB-CT) scans? Today, more practitioners are purchasing cone-beam technology for their offices. These devices have fabulous potential and in certain cases can be of tremendous benefit; however, as with most new technology, when it comes out on the market, it is often ahead of both the learning curve and the potential liability exposure curve.

S236: Utilization and Manipulation of 3- Dimensional CT by the Oral and Maxillofacial Surgeon

Many new technologies are available to assist the oral and maxillofacial surgeon with diagnosis and treatment of facial trauma, pathology and reconstruction. The ability to produce multi-planar and three dimensional reconstructions from computed axial tomographic data has been present for many years. Widespread utilization of this technology was limited by prohibitive cost, fear of radiation dosage, limited computer power and surgeons’ lack of understanding. Improvement of computed axial tomographic hardware, such as spiral data acquisition protocols, isotropic scanning, multi-slice scanning and in office cone beam technology, provide superior images, ultra fast scanning and limitation of motion artifacts all while limiting radiation dose.

Utilization and Manipulation of Three Dimensional CT by the Oral and Maxillofacial Surgeon

Many new technologies are available to assist the oral and maxillofacial surgeon with diagnosis and treatment of facial trauma, pathology, and reconstruction. The ability to produce multi-planar and three dimensional reconstructions from computed axial tomographic data has been present for many years. Widespread utilization of this technology was limited by prohibitive cost, fear of radiation dosage, limited computer power, and surgeons’ lack of understanding. Improvement of computed axial tomographic hardware, such as spiral data acquisition protocols, isotropic scanning, multi-slice scanning, and cone beam technology, provides superior images, ultra fast scanning, and limitation of motion artifacts all while limiting radiation dose.

3D Craniofacial Imaging—Cone Beam Technology

3D Craniofacial Imaging—Cone Beam Technology

Ex vivo bone mineral density of the wrist: influence of medullar fat

The cone beam technology was recently proposed in a third generation of densitometers (dual photon X-ray absorptiometry, DXA such as the Lexxos densitometer). Because fat is a well-known problem with DXA, we have designed a cadaver study to compare the influence of medullary lipids on the measures performed with the Hologic QDR4500 and the Lexxos. Twenty-three human distal radii were obtained and analyzed in parallel on both densitometers; bone mineral density (BMD) was measured at the distal radius with standard softwares and on a standardized square regions of interest (ROI). Bones were then defatted and a new series of measurement was performed. Bones were then thoroughly dried and a cube was prepared at the distal radius with a banding saw. Trabecular and total bone volumes were measured by microcomputerized tomography. Ash eight was obtained after calcination of the blocks. BMD could be measured on the Lexxos before and after delipidation but this was not possible with the QDR4500. The X-ray image quality was better with the Lexxos. Delipidation had a very significant effect on measurements: after defatting, BMD values were considerably reduced (−49.8 ± 19.4%). BMD before/after defatting were significantly correlated ( r = 0.81, P < 0.0001) but bone mass appeared to reflect 66% of the variance. BMD was significantly correlated with BV/TV after defatting ( r = 0.44, P < 0.03) but the correlation improved when cortices were taken into account ( r = 0.70, P < 0.0001). Ash weight was significantly correlated with BMD and total bone volume (respectively, r = 0.84, P < 0.0001; r = 0.53, P < 0.03), but not with BV/TV. BMD at the distal radius is influenced by marrow fat and cortical density.