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Granlund C, Thilander-Klang A, Ylhan B, Lofthag-Hansen S, Ekestubbe A. Absorbed organ and effective doses from digital intra-oral and panoramic radiography applying the ICRP 103 recommendations for effective dose estimations. Br J Radiol 2016; 89:20151052. [PMID: 27452261 DOI: 10.1259/bjr.20151052] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE During dental radiography, the salivary and thyroid glands are at radiation risk. In 2007, the International Commission on Radiological Protection (ICRP) updated the methodology for determining the effective dose, and the salivary glands were assigned tissue-specific weighting factors for the first time. The aims of this study were to determine the absorbed dose to the organs and to calculate, applying the ICRP publication 103 tissue-weighting factors, the effective doses delivered during digital intraoral and panoramic radiography. METHODS Thermoluminescent dosemeter measurements were performed on an anthropomorphic head and neck phantom. The organ-absorbed doses were measured at 30 locations, representing different radiosensitive organs in the head and neck, and the effective dose was calculated according to the ICRP recommendations. RESULTS The salivary glands and the oral mucosa received the highest absorbed doses from both intraoral and panoramic radiography. The effective dose from a full-mouth intraoral examination was 15 μSv and for panoramic radiography, the effective dose was in the range of 19-75 μSv, depending on the panoramic equipment used. CONCLUSION The effective dose from a full-mouth intraoral examination is lower and that from panoramic radiography is higher than previously reported. Clinicians should be aware of the higher effective dose delivered during panoramic radiography and the risk-benefit profile of this technique must be assessed for the individual patient. ADVANCES IN KNOWLEDGE The effective dose of radiation from panoramic radiography is higher than previously reported and there is large variability in the delivered radiation dosage among the different types of equipment used.
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Affiliation(s)
- Christina Granlund
- 1 Department of Oral and Maxillofacial Radiology, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Anne Thilander-Klang
- 2 Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,3 Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Betȕl Ylhan
- 4 Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Ege University, Izmir, Turkey
| | - Sara Lofthag-Hansen
- 5 Clinic of Oral and Maxillofacial Radiology, Public Dental Service, Gothenburg, Sweden
| | - Annika Ekestubbe
- 1 Department of Oral and Maxillofacial Radiology, Institute of Odontology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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Svenson B, Larsson L, Båth M. Optimization of exposure in panoramic radiography while maintaining image quality using adaptive filtering. Acta Odontol Scand 2015; 74:229-35. [PMID: 26478956 DOI: 10.3109/00016357.2015.1100752] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Objective The purpose of the present study was to investigate the potential of using advanced external adaptive image processing for maintaining image quality while reducing exposure in dental panoramic storage phosphor plate (SPP) radiography. Materials and methods Thirty-seven SPP radiographs of a skull phantom were acquired using a Scanora panoramic X-ray machine with various tube load, tube voltage, SPP sensitivity and filtration settings. The radiographs were processed using General Operator Processor (GOP) technology. Fifteen dentists, all within the dental radiology field, compared the structural image quality of each radiograph with a reference image on a 5-point rating scale in a visual grading characteristics (VGC) study. The reference image was acquired with the acquisition parameters commonly used in daily operation (70 kVp, 150 mAs and sensitivity class 200) and processed using the standard process parameters supplied by the modality vendor. Results All GOP-processed images with similar (or higher) dose as the reference image resulted in higher image quality than the reference. All GOP-processed images with similar image quality as the reference image were acquired at a lower dose than the reference. This indicates that the external image processing improved the image quality compared with the standard processing. Regarding acquisition parameters, no strong dependency of the image quality on the radiation quality was seen and the image quality was mainly affected by the dose. Conclusions The present study indicates that advanced external adaptive image processing may be beneficial in panoramic radiography for increasing the image quality of SPP radiographs or for reducing the exposure while maintaining image quality.
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MESH Headings
- Filtration/instrumentation
- Humans
- Image Processing, Computer-Assisted/methods
- Image Processing, Computer-Assisted/standards
- Phantoms, Imaging
- Radiation Dosage
- Radiographic Image Enhancement/methods
- Radiography, Dental, Digital/methods
- Radiography, Dental, Digital/standards
- Radiography, Panoramic/methods
- Radiography, Panoramic/standards
- Skull/diagnostic imaging
- Technology, Radiologic/methods
- X-Ray Intensifying Screens
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Affiliation(s)
- Björn Svenson
- a Department of Oral Radiology , Postgraduate Dental Education Center , Örebro , Sweden
- b Faculty of Medicine and Health , School of Health and Medical Sciences, Örebro University , Örebro , Sweden
- c Department of Radiology , Skaraborg Hospital Skövde , Skövde , Sweden
| | - Lars Larsson
- c Department of Radiology , Skaraborg Hospital Skövde , Skövde , Sweden
| | - Magnus Båth
- d Department of Medical Physics and Biomedical Engineering , Sahlgrenska University Hospital , Gothenburg , Sweden
- e Department of Radiation Physics , Institute of Clinical Sciences at Sahlgrenska Academy, University of Gothenburg , Gothenburg , Sweden
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Modern dental imaging: a review of the current technology and clinical applications in dental practice. Eur Radiol 2010; 20:2637-55. [PMID: 20544352 DOI: 10.1007/s00330-010-1836-1] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Revised: 04/15/2010] [Accepted: 04/29/2010] [Indexed: 02/02/2023]
Abstract
A review of modern imaging techniques commonly used in dental practice and their clinical applications is presented. The current dental examinations consist of intraoral imaging with digital indirect and direct receptors, while extraoral imaging is divided into traditional tomographic/panoramic imaging and the more recently introduced cone beam computed tomography. Applications, limitations and current trends of these dental "in-office" radiographic techniques are discussed.
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Kaeppler G, Dietz K, Reinert S. Diagnostic accuracy ofin vitropanoramic radiographs depending on the exposure. Dentomaxillofac Radiol 2007; 36:68-74. [PMID: 17403882 DOI: 10.1259/dmfr/53852973] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES The aim was to evaluate the effect of dose reduction on diagnostic accuracy in panoramic radiographs with increased tube potential and reduced milliampere settings. METHODS Panoramic radiographs of 12 dried human skulls prepared with lesions in the bone, teeth and peri-implant bone in ascending size were taken. Medium and regular film--screen combinations and a storage phosphor system were used for imaging. All systems were exposed at a low and a high tube potential level. To compare the dose at different tube potential settings, dose length product was measured at the secondary collimator. Five observers assessed the presence (response: 1) or absence (response: 0) of lesions. Sensitivity, specificity and diagnostic accuracy were evaluated and 36 000 ratings were made in all. All settings were repeated once. Intrarater agreement was expressed by Cohen's kappa coefficient. RESULTS There was no significant difference in diagnostic accuracy between a medium and a regular film--screen combination at a low tube potential level (70 kV; 0.935 and 0.930) and the medium film--screen system at a high tube potential level (85 kV; 0.926). Compared with this group, the regular film-screen combinations at high tube potential level (85 kV, 0.906) and all digital radiographs were significantly different (0.886 and 0.866), irrespective of the tube potential level. The digital panoramic radiograph was only comparable with the best film--screen combinations with an exposure for a medium film-screen system and at a low tube potential level. Sensitivity was 89.9% and specificity 93.7%. The kappa coefficient for intrarater agreement was high (0.81). CONCLUSIONS The medium intensifying screen can be used at high tube potential settings instead of low tube potential settings, or the regular intensifying screen can be used at low tube potential settings with the same diagnostic value. A dose reduction of about 40% is possible. The storage phosphor plates should be exposed at least like a regular film-screen system and at a low tube potential level.
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Affiliation(s)
- G Kaeppler
- Department of Oral Radiology, School of Dental Medicine, University of Tübingen, Tübingen, Germany.
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5
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Kaeppler G, Dietz K, Reinert S. Influence of tube potential setting and dose on the visibility of lesions in intraoral radiography. Dentomaxillofac Radiol 2007; 36:75-9. [PMID: 17403883 DOI: 10.1259/dmfr/75743437] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES The objectives were to determine the diagnostic accuracy of different image receptors when first, the tube potential setting was increased from 60 kV to 90 kV and second, when the milliampere setting was reduced at unchanged tube potential for storage phosphor plates. METHODS Intraoral radiographs (films of speed class F, storage phosphor plates) were taken of 12 dried human skulls prepared with lesions in both teeth and peri-implant bone, in ascending size. Five observers assessed the presence (response=1) or absence (response=0) of lesions. The digital intraoral radiograph was exposed at 60 kV and 90 kV with half and a quarter of the film exposure. Some of the radiographs were assessed a second time. In total, 6000 assessments were made. Intrarater agreement was expressed by Cohen's kappa coefficient. RESULTS The digital combinations showed the lowest diagnostic accuracy in all combinations, but the results demonstrated an equivalence of all combinations of films and storage phosphor plates. The differences in diagnostic accuracy were low (94-96.5%). The kappa coefficient for intrarater agreement was high (0.85). CONCLUSIONS Regarding peri-implant and decayed lesions, intraoral films and storage phosphor plates demonstrated equal quality in this in vitro study regardless of exposure at 60 kV or 90 kV.
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Affiliation(s)
- G Kaeppler
- Department of Oral Radiology, School of Dental Medicine, University of Tübingen, Tübingen, Germany.
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Kaeppler G, Dietz K, Reinert S. The effect of dose reduction on the detection of anatomical structures on panoramic radiographs. Dentomaxillofac Radiol 2006; 35:271-7. [PMID: 16798925 DOI: 10.1259/dmfr/16653683] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES The aim was to evaluate the effect of dose reduction on diagnostic accuracy using different screen-film combinations and digital techniques for panoramic radiography. METHODS Five observers assessed 201 pairs of panoramic radiographs (a total of 402 panoramic radiographs) taken with the Orthophos Plus (Sirona, Bensheim, Germany), for visualization of 11 anatomical structures on each side, using a 3-point scale -1, 0 and 1. Two radiographs of each patient were taken at two different times (conventional setting and setting with decreased dose, done by increasing tube potential settings or halving tube current). To compare the dose at different tube potential settings dose-length product was measured at the secondary collimator. Films with medium and regular intensifying screens (high and low tube potential settings) and storage phosphor plates (low tube potential setting, tube current setting equivalent to regular intensifying screen and halved) were compared. The five observers made 27 610 assessments. Intrarater agreement was expressed by Cohen's kappa coefficient. RESULTS The results demonstrated an equivalence of regular screens (low tube potential setting) and medium screens (high and low tube potential settings). A significant difference existed between medium screens (low tube potential setting, mean score 0.92) and the group of regular film-screen combinations at high tube potential settings (mean score 0.89) and between all film-screen combinations and the digital system irrespective of exposure (mean score below 0.82). There were no significant differences between medium and regular screens (mean score 0.88 to 0.92) for assessment of the periodontal ligament space, but there was a significant difference compared with the digital system (mean score below 0.76). The kappa coefficient for intrarater agreement was moderate (0.55). CONCLUSIONS New regular intensifying screens can replace medium screens at low tube potential settings. Digital panoramic radiographs should be taken at low tube potential levels with an exposure equivalent at least to a regular intensifying screen.
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Affiliation(s)
- G Kaeppler
- Department of Oral Radiology, School of Dental Medicine, University of Tübingen, Tübingen, Germany.
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Gijbels F, Jacobs R, Bogaerts R, Debaveye D, Verlinden S, Sanderink G. Dosimetry of digital panoramic imaging. Part I: patient exposure. Dentomaxillofac Radiol 2005; 34:145-9. [PMID: 15897284 DOI: 10.1259/dmfr/28107460] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES To measure patient radiation dose during panoramic exposure with various panoramic units for digital panoramic imaging. METHODS An anthropomorphic phantom was filled with thermoluminescent dosemeters (TLD 100) and exposed with five different digital panoramic units during ten consecutive exposures. Four machines were equipped with a direct digital CCD (charge coupled device) system, whereas one of the units used storage phosphor plates (indirect digital technique). The exposure settings recommended by the different manufacturers for the particular image and patient size were used: tube potential settings ranged between 64 kV and 74 kV, exposure times between 8.2 s and 19.0 s, at fuse current values between 4 mA and 7 mA. The effective radiation dose was calculated with inclusion of the salivary glands. RESULTS Effective radiation doses ranged between 4.7 microSv and 14.9 microSv for one exposure. Salivary glands absorbed the most radiation for all panoramic units. When indirect and direct digital panoramic systems were compared, the effective dose of the indirect digital unit (8.1 microSv) could be found within the range of the effective doses for the direct digital units (4.7-14.9 microSv). CONCLUSIONS A rather wide range of patient radiation doses can be found for digital panoramic units. There is a tendency for lower effective doses for digital compared with analogue panoramic units, reported in previous studies.
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Affiliation(s)
- F Gijbels
- Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Katholieke Universiteit Leuven, Kapucijnenvoer 7, 3000 Leuven, Belgium
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Gijbels F, Sanderink G, Wyatt J, Van Dam J, Nowak B, Jacobs R. Radiation doses of indirect and direct digital cephalometric radiography. Br Dent J 2004; 197:149-52; discussion 140. [PMID: 15311250 DOI: 10.1038/sj.bdj.4811532] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2003] [Accepted: 10/23/2003] [Indexed: 11/09/2022]
Abstract
AIM The aim of this study was to measure organ doses and calculate the effective dose for indirect and direct digital cephalometric exposures. MATERIAL AND METHODS Indirect digital cephalometric exposures were made of a Rando phantom head using a Cranex Tome multipurpose unit with storage phosphor plates from Agfa and the direct digital (Charge Coupled Device, CCD) exposures were made with a Proline Ceph CM unit. Exposure settings were 70 kV and 4 mAs for indirect digital exposures. Direct digital exposures were made with 70 kV, 10 mA and a total scanning time of 23 s. TLD700 dosemeters were used to measure organ doses, and the effective doses were calculated with (effective dose(sal)) and without inclusion of the salivary glands. A pilot study was carried out to compare diagnostic image quality of both imaging modalities. RESULTS Effective doses were 1.7 microSv for direct digital and 1.6 microSv for indirect digital cephalometric imaging. When salivary glands were included in the calculation, effective doses(sal) were 3.4 microSv and 2.2 microSv respectively. Organ doses were higher for direct digital imaging, except for the thyroid gland, where the organ doses were comparable. Diagnostic image quality of indirect and direct digital cephalometric images seemed comparable. CONCLUSION Effective dose and effective dose(sal) were higher for direct digital cephalometric exposure compared with indirect digital exposure. Organ doses were higher for direct digital cephalography. From preliminary data, it may be presumed that diagnostic image quality of indirect and direct digital cephalometric images are comparable.
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Affiliation(s)
- F Gijbels
- Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Katholieke Universiteit Leuven, Belgium
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Mastoris M, Li G, Welander U, McDavid WD. Determination of the resolution of a digital system for panoramic radiography based on CCD technology. ACTA ACUST UNITED AC 2004; 97:408-14. [PMID: 15024369 DOI: 10.1016/j.tripleo.2003.10.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVES To determine Line Spread Functions (LSFs) and Modulation Transfer Functions (MTFs) for a digital system for panoramic radiography: the Dimax I (Planmeca Oy, Helsinki, Finland) based on Charge-Coupled Device (CCD) technology. STUDY DESIGN A test object was specially designed having a gold foil positioned vertically. Images of the gold foil created edge functions that were used to determine LSFs and MTFs. The design of the test object made it possible to move the gold foil forward and backward relative to the central plane of the image layer by means of a micrometer screw. The experiment was carried out for different object depths in 5 different regions: the anterior, the canine, the premolar, the molar, and the TMJ regions. LSFs and MTFs were calculated using specially designed software. RESULTS The results are presented graphically. LSFs and MTFs for the central plane were essentially the same for all regions. The MTFs for different object depths in the 5 investigated regions exhibited typical characteristics of MTFs for panoramic radiography with the exception for the functions for the molar region. CONCLUSIONS The present findings indicate that the resolution of the Dimax I CCD system is comparable to that of film-based panoramic radiography.
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Affiliation(s)
- Mihalis Mastoris
- Department of Oral Diagnosis and Radiology, School of Dentistry, University of Athens, Ampelokipi, Greece.
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Ekestubbe A, Thilander-Klang A, Lith A, Gröndahl HG. Effective and organ doses from scanography and zonography: a comparison with periapical radiography. Dentomaxillofac Radiol 2004; 33:87-92. [PMID: 15313999 DOI: 10.1259/dmfr/24877187] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES To compare absorbed and effective doses from scanographic and zonographic examinations performed in the Scanora unit with intraoral periapical radiography. METHODS Absorbed dose measurements were made on an anthropomorphic phantom head with LiF thermoluminescent dosemeters in the regions of the pituitary gland, eye lenses, parotid glands, submandibular glands, thyroid gland and skin. Energy imparted was calculated from the measurements of air collision kerma and effective doses by using the quotient 24 mSv J-1 between energy imparted and effective dose. The upper and lower third molar region was examined with intraoral radiographs and with ramus scanograms, dental scanograms and dental zonograms. Radiation dose measurements were also performed for Scanora panoramic radiography (jaw and dental). RESULTS The effective doses for the ramus and dental scanograms were 0.01 mSv, similar or lower than for intraoral radiography. Zonography yielded the highest effective dose (0.03 mSv). Except for the skin doses, the salivary glands received the highest doses. Salivary gland doses were slightly higher from narrow beam than from intraoral radiography. CONCLUSIONS Detail narrow beam radiography with the Scanora is an alternative to periapical radiography and is preferred, from a radiation dose point of view, over zonography.
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Affiliation(s)
- A Ekestubbe
- Department of Oral and Maxillofacial Radiology, Faculty of Odontology, The Sahlgrenska Academy at Göteborg University, Göteborg, Sweden.
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Molander B, Gröndahl HG, Ekestubbe A. Quality of film-based and digital panoramic radiography. Dentomaxillofac Radiol 2004; 33:32-6. [PMID: 15140820 DOI: 10.1259/dmfr/17777906] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES To compare the image quality of panoramic radiographs obtained with storage phosphor plate and screen-film systems. METHODS Panoramic radiographs were taken in 60 patients both with film and with a storage phosphor plate system (30 with DenOptix (Dentsply/Gendex) and 30 with Digora PCT). The images were obtained with either the Cranex Tome or the Scanora multimodal X-ray unit. The screen-film combination was Lanex medium/Curix Ortho HT-G. The digital images were displayed as 8-bit images with a 300 dpi resolution on a 19" monitor and the film images were placed on a light box adjacent to the screen. Ten observers evaluated diagnostic image quality by means of visual grading analysis of different anatomical structures. The structures were scored as being visualized much better (5), better (4), equal (3), worse (2) or much worse (1) in the digital images than in the film images. The mean number of patients receiving the different scores was calculated. Statistical methods used were Wilcoxon sign rank test and Mann-Whitney test. RESULTS On average, visualization was equal in 19 of the 30 patients imaged using Digora PCT; in 10 it was worse. The corresponding values for DenOptix were 20 and 9. The difference between the film-based and the digital images was small but statistically significant (P<0.0001). The difference between the two image plate systems was not statistically significant (P>/=0.17). CONCLUSIONS It was concluded that digital panoramic radiographs are equivalent to film-based images for most purposes.
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Affiliation(s)
- B Molander
- Clinic of Oral and Maxillofacial Radiology, Göteborg Public Dental Service, Göteborg, Sweden.
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Ekestubbe A, Gröndahl HG, Molander B. Quality of digital pre-implant tomography: comparison of film–screen images with storage phosphor images at normal and low dose. Dentomaxillofac Radiol 2003; 32:322-6. [PMID: 14709608 DOI: 10.1259/dmfr/50054523] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES The aim of this pilot study was to compare the image quality of a storage phosphor system with that of conventional film-screen in pre-implant conventional tomography, and to test the influence of radiation dose on image quality in the storage phosphor system. METHODS Cross-sectional conventional tomographic images (Scanora) technique) were obtained on 11 patients with film-screen and with storage phosphor image plates (Digora) PCT) at normal and low doses. Ten observers graded the visibility of anatomical structures of importance for implant planning. A three-step rating scale was used, where -1 =worse, 0=equal and 1=better than the reference image. RESULTS Although image quality was graded as equally good in the majority (59%) of images, the storage phosphor system scored significantly lower than film-screen (-0.37 vs 0.00, respectively) for all the images. Low dose storage phosphor images were rated significantly lower (-0.21) than normal dose images (0.00). CONCLUSIONS In the majority of patients, anatomic structures of importance for implant planning are visualized equally well on storage phosphor and film-screen images. However, where differences do exist, storage phosphor images score lower than film-screen images. Dose reduction in the storage phosphor system had a negative influence on image quality.
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Affiliation(s)
- A Ekestubbe
- Department of Oral and Maxillofacial Radiology, Faculty of Odontology, The Sahlgrenska Academy at Göteborg University, Göteborg, Sweden.
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Wenzel A, Gotfredsen E. Digital radiography for the orthodontist. Am J Orthod Dentofacial Orthop 2002; 121:231-5; quiz 192. [PMID: 11840134 DOI: 10.1067/mod.2002.121366] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Ann Wenzel
- Department of Oral Radiology, Royal Dental College, University of Aarhus, Denmark
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Abstract
The introduction of the computed tomograph in the 1970s revolutionized medical diagnosis by initiating the transition from analogue to digital imaging. During this period, more specialized equipment for image processing was developed, such as cathode-ray tubes for image display, special sensors for image acquisition, and storage devices for image archiving. Digital imaging systems designed exclusively for use in dentistry were developed in the latter half of the 1980s. Some are now being clinically applied under conditions of close scrutiny to determine diagnostic accuracy, image quality, and radiation exposure to patients. This article reviews the enabling technologies of digital systems used in dentistry, and focuses upon intraoral digital imaging systems, concepts for digital image acquisition, and variations in radiation dose and their effects on diagnostic accuracy of caries detection.
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Affiliation(s)
- M Wakoh
- Department of Oral and Maxillofacial Radiology, Tokyo Dental College, Chiba, Japan
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Farman TT, Farman AG. Temporomandibular joint pantomography using charge-coupled device, photostimulable phosphor, and film receptors: a comparison. J Digit Imaging 1999; 12:9-13. [PMID: 10342155 PMCID: PMC3452917 DOI: 10.1007/bf03168744] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Our objective was to compare the accuracy and practicality in use of three available imaging receptors for temporomandibular joint (TMJ) imaging; namely, two computer-assisted and one traditional analog x-ray film system. A standardized tissue-equivalent encased human skull specimen was imaged using lateral and posteroanterior (PA) pantomographic projections with the Orthopantomograph OP 100 (Instrumentarium Imaging, Tuusula, Finland) and three different receptor modalities: (1) Ektavision film with Ektavision screens (Eastman Kodak, Rochester, NY); (2) DenOptix photostimulable phosphor screens (Dentsply/Gendex, Chicago, IL); and (3) the charge-coupled device (CCD) receptor, DigiPan (TREX/Trophy Radiology, Marne-la-Vallée, France). The effective focal trough was found for each receptor using lead resolution grids placed at fractional millimeter distances along empirically determined beam projection angulations. The time to acquire and process images was also established. We found that the CCD system permitted real-time display, whereas the use of traditional film took 2 minutes to load the cassette in a darkroom and perform the exposure, and then a further 2 minutes to unload and process. The storage phosphor took 3 minutes to unload the cassette and process the image and a further 20 seconds to clear the plate following laser scanning. Film produced the greatest maximum resolution followed by the storage phosphor and the CCD. In conclusion, CCD-based TMJ pantomography provided an instant image. The photostimulable phosphor system used was the least satisfactory in terms of the time expended to obtain an image, but provided better spatial resolution than the CCD. Ektavision film/screens provided the best spatial resolution in this investigation.
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Affiliation(s)
- T T Farman
- Division of Radiology and Imaging Sciences, University of Louisville, Louisville Health Sciences Center, KY 40292, USA
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