Role of computerized tomography in dental implantology

The authors report their experience using CT examination in implantology, outlining the advantages of this method in the study of the perimplantar bone, both in cases undergoing a favourable evolution and in those with an unsatisfactory outcome.     

New imaging with computed tomography in dental implantology]

The authors report on a new image processing technique, for the imaging of both mandible and maxilla, which is very useful for oral specialists, especially in pre- and postoperative protocols for dental implants. After performing very thin axial scans (1-2 mm) with overlapping and without gantry tilt, of the mandible and/or maxilla, the data are reconstructed with a Elscint DentaCT software. With this program, multiple panoramic alveolar views can be obtained in a very short time (about 5 minutes), with a focal plane which can be easily modified by the operator; these planes are parallel to the curved axis of maxilla or mandible. Furthermore, the operator can get multiple images absolutely cross-sectional to the curved axis of alveolar regions (radial sections) and can image the number of cross-sectional planes and the distance between them. In all studied patients (41 over the last 6 months, 66 images overall), DentaCT yielded an excellent representation not only of all anatomical structures but also of every single implant; this allowed a complete preoperative planning based on morphovolumetric, densitometric and spatial data, together with the correct evaluation of implant positioning and of osteointegration success.     

Scanner in dental implantology

Computerized tomography allows a life-size morphological study and analysis of bony texture. The life-size documents obtained allow direct measurement on the radiographic coefficient. Computerized tomography guides coefficient. Computerized tomography guides implant procedures: possibility of intra-osseous implantation, choice of implant (length and diameter), position of the implant, site of the implant in the cancellus bone or in contact with the cortex.     

Computed tomography: cost and efficacy implications.

Because CT is unique, it has been accepted by physicians with unrestrained enthusiasm. However, the capital investment and cost of maintenance are high, and there has been no orderly program of dispersion despite the profound interest of the regulatory agencies in cost containment. Although the diagnostic accuracy of CT in both the head and body is high, its information gain over other competing imaging methods, particularly those in the abdomen (ultrasound, nuclear medicine), has not been fully documented. In evaluating the cost effectiveness of CT, long-term outcome, while the most important criterion, requires carefully controlled studies over many years. Short-term value may be measured by assessing the degree to which CT furnishes new diagnostic information, its accuracy, its effect on the morbidity and mortality of diagnostic and theraupeutic procedures, its impact on treatment planning, and changes in cost and saving incident to its use. Prospective studies must relate the contribution of CT to that of competing methods and document the impact of additional diagnostic information.     

Computed tomography: an overview

Instrumentation for computed tomography (CT) can be put into three categories that are defined in this article. The basis for this categorization depends on the number of detectors and the type of scanning mode used by each. The goal of each generation scanner is to provide a measurement of x-ray absorption coefficients of cross-sectional portions of the anatomy. The technology of each generation is also presented.     

Computed tomography in sciatica

Lumber facet arthropathy and a herniated disk are two major causes of low back pain and sciatica. The authors evaluated the importance of computed tomography (CT) in 243 patients with low back pain and/or sciatica. Lumbar facet abnormalities were found in 139 patients (57%), and a herniated disk was found in 48 patients (20%). CT findings correlated precisely with surgical observations in cases involving a herniated disk and correlated well with the results of an intra-articular facet block in a small series of patients. CT can effectively diagnose and differentiate between lumbar facet arthropathy and a herniated disk.     

Computed tomography in meningitis

Summary Computed tomography in 34 cases of meningitis has revealed a spectrum of findings. In acute cases these include enlargement of the subarachnoid spaces, generalized contrast enhancement of the meninges and ependyma, sterile and pyogenic subdural collections, cortical infarction, and cerebral necrosis.     

Computed tomography in ascites

Ascites can be found in a variety of diseases and may represent either a late complication or the clinical sign of a pathologic condition. The presence of even small fluid collections in peritoneal recess can be easily detected by CT. A number of reports confirm CT prediction of the benign/malignant nature of ascites. The CT scans of 100 patients affected with histologically confirmed ascites were reviewed to evaluate CT contribution to the assessment of the benign/malignant nature of ascites. On the basis of our results, it can be concluded that the only highly predictive CT finding of malignant ascites is the presence of a coexisting mass. Other findings do not allow the two types of collections to be discriminated.     

Magnetic Resonance applications in dental implantology: technical notes and preliminary results

PURPOSE: To evaluate the possible use of Magnetic Resonance Imaging (MRI) in the field of dental implantology, for identifying the mandibular nerve, as proposed by several authors. MATERIALS AND METHODS: MRI was used for the study of the mandible in ten subjects (five healthy volunteers and five subjects awaiting dental implants). Imaging was performed on a 1.0-T MR scanner with a brain coil. T2 TSE, T1 spin-echo and T2 gradient-echo sequences were performed, both parallel and perpendicular to the horizontal portion of the mandible, with a thickness of 3 mm. RESULTS: In all the subjects MRI clearly identified the intraosseous course of the inferior alveolar neurovascular bundle within the mandibular canal. CONCLUSIONS: MRI appears useful for the depiction of the mandibular canal before dental implantation. Further studies are required to compare the accuracy of MRI and CT based on a statistically significant sample.     

Computed tomography in ophthalmology

Summary The practical value of density measurements with computed tomography of orbital lesions is demonstrated.     

Computed tomography dacryocystography

Twenty-one patients with epiphora were examined by conventional dacryocystography, using Lipiodol as a contrast medium, and CT dacryocystography, using a water soluble contrast medium. In the latter, the material was not introduced under pressure but three or four drops were administered, providing a physiological method of investigation. Subsequently, CT dacryocystography provides functional information about lacrimal disorders and is easy to use.     

Computed tomography angiography

Cardiovascular disease kills more adults in the United States each year than any other medical condition. Although these diseases are largely preventable, the number of newly diagnosed patients continues to climb. Angiography traditionally involves invasive catheter examinations, but recent advances have allowed computed tomography angiography (CTA) to supplant traditional angiography as a first-line diagnostic imaging modality to assess cardiovascular disease. Often used to diagnose vascular pathologies in symptomatic patients, CTA also is useful in early detection of coronary and peripheral artery diseases. CTA will play an increasingly important role in cardiovascular medicine as technological advances improve image data acquisition, processing speeds, and image reconstruction.     

Computed tomography enteroclysis: a review

Computed tomography (CT) enteroclysis is being performed routinely for evaluation of suspected small bowel diseases. The availability of multidetector CT scanners has further increased the diagnostic yield of enteroclysis. There is excellent depiction of small bowel wall pathology on CT enteroclysis especially with use of negative enteric contrast. We discuss the CT enteroclysis technique and procedure along with the imaging spectrum of some common small bowel pathologies.