• Imaging Science in Dentistry
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• 제33권3호
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• pp.137-141
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• 2003

Purpose: To evaluate the precision of measurements taken of dental implants in bucco-lingually sectioned views of the maxilla by linear tomograms of the panorama and to assess the visibility of the inferior wall of the maxillary sinus. Materials and Methods : Eighty sites prepared with implants of gutta percha cone in the sockets of the upper premolars and molars of 10 dry skulls were radiographically examined using linear tomograms of panorama, and scanned coronally and axially by computed tomography. The differences in mm between the measurements in bucco-lingually sectioned images of maxillary alveolar bone and the true length and width of the implanted gutta percha cones were compared as mean values (mean) and standard deviations (SD) for each radiographic technique. Linear tomography of panorama was compared with computed tomography for visualization of the relationship between the inferior wall of maxillary sinus and the end of each implant. Results: The deviations between the actual implant length and the measured values taken from the linear tomograms (0.44±0.39 mm) was significantly less than the measured values from the multiplanar reconstructed images of the axially scanned computed tomogram (1.21 ± 0.90 mm). There was statistically significant difference (p < 0.05) between two techniques in the differences between the measurements and true implant length. The relationship of the inferior border of maxillary sinus with end of implant was worse identified with the linear tomogram of panorama (68%) than the multiplanar reconstructed image of axially scanned computed tomogram (99%). Conclusion: We could not find any differences in the accuracy of length measurement between the linear tomogram of panorama and computed tomogram, but computed tomogram allowed for a better visualization of the inferior wall of the maxillary sinus than the linear tomogram.

• Imaging Science in Dentistry
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• 제52권2호
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• pp.133-140
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• 2022

Purpose: The aim of this review was to systematically analyze the available literature on the correlation between the gray values (GVs) of cone-beam computed tomography (CBCT) and the Hounsfield units (HUs) of computed tomography (CT) for assessing bone mineral density. Materials and Methods: A literature search was carried out in PubMed, Cochrane Library, Google Scholar, Scopus, and LILACS for studies published through September 2021. In vitro, in vivo, and animal studies that analyzed the correlations GVs of CBCT and HUs of CT were included in this review. The review was prepared according to the PRISMA checklist for systematic reviews, and the risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies tool. A quantitative analysis was performed using a fixed-effects model. Results: The literature search identified a total of 5,955 studies, of which 14 studies were included for the qualitative analysis and 2 studies for the quantitative analysis. A positive correlation was observed between the GVs of CBCT and HUs of CT. Out of the 14 studies, 100% had low risks of bias for the domains of patient selection, index test, and reference standards, while 95% of studies had a low risk of bias for the domain of flow and timing. The fixed-effects meta-analysis performed for Pearson correlation coefficients between CBCT and CT showed a moderate positive correlation (r=0.669; 95% CI, 0.388 to 0.836; P<0.05). Conclusion: The available evidence showed a positive correlation between the GVs of CBCT and HUs of CT.

• Imaging Science in Dentistry
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• 제37권4호
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• pp.191-195
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• 2007

Purpose: To study the intra- and interobserver agreement of multidetector row computed tomography (MDCT) in interpretation of degenerative changes of the mandibular condyle. Materials and Methods: Five observers independently evaluated one hundred temporomandibular joint MDCT images for signs of osteophytes, erosion, sclerosis and flattening. The intra- and interobserver agreements were calculated by using Kappa statistics. Results: The intraobserver agreement was substantial for erosion (k=0.75), flattening (k=0.74) and sclerosis (k=0.72) and almost perfect for osteophytes (k=0.84). The interobserver agreement was fair for flattening (k=0.39), moderate for erosion (k=0.58) and sclerosis (k=0.48) and substantial for osteophytes (k=0.75). Conclusion: This study shows that we can expect good agreement for the presence of osteophytes, but not for flattening in the interpretation of MDCT images of the condyle.

• Imaging Science in Dentistry
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• 제44권3호
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• pp.177-183
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• 2014

Recent research in endodontics has highlighted the need for three-dimensional imaging in the clinical arena as well as in research. Three-dimensional imaging using computed tomography (CT) has been used in endodontics over the past decade. Three types of CT scans have been studied in endodontics, namely cone-beam CT, spiral CT, and peripheral quantitative CT. Contemporary endodontics places an emphasis on the use of cone-beam CT for an accurate diagnosis of parameters that cannot be visualized on a two-dimensional image. This review discusses the role of CT in endodontics, pertaining to its importance in the diagnosis of root canal anatomy, detection of periradicular lesions, diagnosis of trauma and resorption, presurgical assessment, and evaluation of the treatment outcome.

• Journal of Chest Surgery
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• 제53권5호
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• pp.310-312
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• 2020

Transcatheter leadless pacemaker dislodgment is a rare and potentially fatal complication of leadless device implantation. We present the first case of multidetector computed tomography images of leadless pacemaker migration and embolization in the pulmonary middle lobe artery. The patient was managed by percutaneous retrieval of the dislodged device and re-implantation in the appropriate position.

• Journal of Trauma and Injury
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• 제28권3호
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• pp.195-197
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• 2015

Artifacts can seriously degrade the quality of computed tomography (CT) images, sometimes to the point of making them diagnostically unusable. Here, we report an unusual CT artifact that could have resulted in the misdiagnosis of a hyperdense hemorrhagic lesion in a 55-year-old man. The author recommend that when hemorrhagic lesion in posterior fossa is suggested on CT, the physician should carefully consider all patient-related clinical data prior to considering surgical intervention or a biopsy. Cranial magnetic resonance imaging (MRI) can help in preventing the misdiagnosis as hemorrhage of CT scan.

• Clinical and Experimental Pediatrics
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• 제58권12호
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• pp.501-504
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• 2015

We present the case of a 5-year-old child with coronary complications due to Kawasaki disease; this patient unintentionally underwent both dual-source computed tomography (DSCT) coronary angiography and invasive coronary angiographic examination in 2 months. This case highlights the strong consistency of the results between DSCT coronary angiography and invasive coronary angiography. Compared to conventional invasive coronary angiography, DSCT coronary angiography offered additional advantages such as minimal invasiveness and less radiation exposure.

• 대한수의학회지
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• 제58권2호
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• pp.99-101
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• 2018

A 5-year-old intact female Persian cat was referred with anorexia and vomiting. Physical examination revealed icterus in the pinna, oral mucosa, and sclera. Ultrasonography revealed several findings including uniformly hyperechoic hepatic parenchyma compared to adjacent falciform fat, increased attenuation of the ultrasound beam, and poor visualization of intrahepatic vessel borders. Computed tomography revealed hypoattenuation of the hepatic parenchyma with a radiodensity value of -60 Hounsfield units. The adjacent intrahepatic vessels appeared hyperattenuated relative to the hepatic parenchyma as if the vessels were contrast-enhanced. Based on ultrasonography and computed tomography results, the cat was tentatively diagnosed as feline hepatic lipidosis.

• Imaging Science in Dentistry
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• 제32권2호
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• pp.61-66
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• 2002

Purpose: To compare the bone height of implant sites measured using panoramic radiography and spiral CT. Materials and Methods : The available bone height was determined for 263 maxillary and mandibular implant sites in 59 patients. Distortion was calculated using the metal bar for the panoramic radiographs. Results: Significant differences in mean bone height between the two imaging modalities were found in maxillary and mandibular anterior regions (p<0.05). The mean difference in bone height recorded by the two techniques was smallest in the maxillary and mandibular molar areas (0.8 mm), and greatest in the mandibular anterior region (1.3 mm). With the exception of the mandibular anterior region, ninety percent of all the sites showed measurement differences within 2 mm. Conclusion: A safety margin of 2 to 3 mm is called for when utilizing panoramic radiography, otherwise additional imaging modality such as computed tomography is necessary to obtain accurate measurements.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제41권3호
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• pp.145-148
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• 2015

In 1942 Stafne reported 35 asymptomatic, radiolucent cavities that were unilaterally located in the posterior region of the mandible between the mandibular angle and the third molar, and below the mandibular canal. The term Stafne bone cavity (SBC) is now used for such asymptomatic lingual bone depressions of the lower jaw. Since then there have been many reports of SBCs but very fews tudies have used cone-beam computed tomography (CBCT) for their diagnosis. The aim of this paper is to describe the clinical and radiological characteristics of two cases of SBCs and the importance of limited CBCT in confirming the diagnosis.