Radioisotope therapy of malignant pheochromocytoma with iodine-131 metaiodobenzylguanidine--absorbed dose assessments using SPECT]

The correlation of absorbed doses D (rad) of tumors in 4 patients with malignant pheochromocytoma, who were treated by 131I-MIBG (3.7 GBq), with their clinical courses were analyzed and the clinical significance of determination of absorbed dose was discussed. Absorbed doses of 131I-MIBG in the tumors were measured by using SPECT at the time of therapy. Absorbed dose was calculated based on the MIRD (medical internal radiation dose committee) equation. Tumor volumes were ranged from 17 g-100 g (mean 40 g), effective half lives were ranged from 1.3 days-5.9 days (mean 3.6 days), and tumor absorbed doses were varied between 5.4 Gy-68 Gy (mean 40 Gy). When the absorbed doses of the tumor exceeded over 40 Gy, good clinical responses were obtained. The initial treatment seemed to be important for 131I-MIBG therapy, since the absorbed doses in the following therapy became reduced. These results indicate that the quantitative SPECT for radioisotope therapy is clinically valid and that the calculated absorbed doses correlate well with clinical responses.     

Comparison of patient dose from imaging protocols for dental implant planning using conventional radiography and computed tomography

OBJECTIVES: To compare the radiation doses from imaging protocols for dental implant planning either using conventional radiography only (dental panoramic radiography (DPR), cephalometry and linear cross-sectional tomography) or involving computed tomography (CT). METHODS: Organ absorbed doses were measured using a female Rando anthropomorphic phantom loaded with lithium fluoride thermoluminescent dosemeters (TLD). Standard mandibular protocols for dental implant planning were followed using either a conventional dental radiographic unit (PM 2002 CC Planmeca, Helsinki, Finland) or CT scanner (Excel Twin Elscint, Haifa, Israel). Organ absorbed and effective doses were calculated. Effective dose was calculated using two approaches, one based on the ICRP method which excludes the salivary tissue from the remainder organs (designated E(exc)), and the other with its inclusion (E(inc)). RESULTS: The greatest individual organ doses for any examination were measured in the salivary tissue. E(exc) for panoramic, cephalometric and cross-sectional tomography using DPR was 0.004 mSv, 0.002 mSv and 0.002 mSv, respectively, whereas with CT it was 0.314 mSv. The value of E(inc) calculated using these data was between two and five times E(exc). CONCLUSIONS: E(inc) greatly increases the apparent radiation burden, especially with high dose procedures. CT techniques can provide excellent images, but at the cost of increased radiation detriment. DPR with a cross-sectional tomography facility may give adequate clinical information at a greatly reduced dose.     

Image quality of two solid-state and three photostimulable phosphor plate digital panoramic systems,and treatment planning of mandibular third molar removal

OBJECTIVES: The purpose was to evaluate image quality of two solid-state (charge-coupled device (CCD)) and three photostimulable phosphor (PSP) plate digital panoramic systems, and to assess their utility for treatment planning before mandibular third molar removal. METHODS: 433 patients were randomly allocated to five digital systems: Dimax2 and Orthophos Plus (both CCD systems) and DenOptix, DigiDent and Digora (all PSP systems). Image quality was evaluated in six regions on a 4-point scale by three independent observers. In addition, an oral surgeon evaluated image quality in the mandibular third molar region only as well as the utility of the image for treatment planning before removal of that molar. RESULTS: Images from the DenOptix and DigiDent systems had a significantly lower overall quality than images from the Digora, Dimax2 and Orthophos Plus systems (P < 0.005). The oral surgeon's assessment of image utility resulted in rejection rates of 0% for Orthophos Plus, 2% for Digora, 8% for Dimax2, 12% for DigiDent and 14% for DenOptix images. The rates for the DigiDent and DenOptix images were significantly higher than those for the other systems (P < 0.001), and the rate for Dimax2 was significantly higher than that for Orthophos Plus (P = 0.002). CONCLUSIONS: The quality of DenOptix and DigiDent digital panoramic images was found to be inferior to the quality found in images obtained with the Digora, Dimax2 and Orthophos Plus systems. Images from the Digora and Orthophos Plus systems were regarded to be the most useful for treatment planning before mandibular third molar removal.     

Dosimetry of digital panoramic imaging. Part I: Patient exposure

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.     

Organ doses and subjective image quality of indirect digital panoramic radiography

OBJECTIVES: To determine if slight variations in exposure will affect diagnostic image quality and absorbed radiation doses for digital and analogue panoramic radiography. METHODS: Thermoluminescent dosimeters were placed in the thyroid gland, eyes, submandibular glands, parotid glands and skin of two human cadaver heads. Three different exposure settings were used: 70 kV, 120 mAs; 77 kV, 75 mAs; and 81 kV, 60 mAs. Subjective image quality was assessed using a phantom head. Storage phosphor (SP) images were printed on film and both analogue and SP images were assessed for their subjective image quality on a five-point rating scale. The results were statistically analysed using logistic regression analysis and chi(2) tests. RESULTS: Highest organ doses were measured for the submandibular glands, followed by the parotid glands. Salivary gland doses tended to be higher at lower kV settings. Image quality was not statistically different for the different exposure settings. Imaging technique did not seem to influence diagnostic image quality, except for the periapical status of upper premolars where SP was better. The main reason for any differences appeared to be interobserver variation. CONCLUSIONS: Analogue and SP panoramic radiography performed equally well for subjective diagnostic image quality. No significant differences could be found at the exposure settings used in this study. Radiation doses were highest for the salivary glands, especially at lower kV settings.     

Optimisation of patient doses in programmable dental panoramic radiography

OBJECTIVES: To estimate the radiation-related risk associated with twelve imaging programs available on the Orthophos (Siemens, Erlangen, Germany) dental panoramic radiography unit. METHODS: Organ absorbed doses for each program were measured using a Rando anthropomorphic phantom loaded with thermoluminescent dosemeters. Effective dose (E) was calculated in two ways; first, using the method recommended by the International Commission on Radiological Protection, which excludes the salivary glands (designated Eexc), and second, with its inclusion (designated Einc). Organ and effective doses were both used to compare the various imaging programs. RESULTS: In 11 of the 12 programs studied the salivary glands received the highest individual organ dose, and Einc was found to be up to double Eexc. When the image was restricted to the dentition (program 2) organ doses were lower than for the complete jaws (program 1) by up to 85%, and Eexc and Einc reduced by about one half. When programs 2 and 6 (to image the temporomandibular joints) are used in place of program 1, the former combination provides more image information at an equivalent risk. CONCLUSIONS: The value of E in panoramic radiography depends on the inclusion of the salivary glands in the calculation and the magnitude of the dose.     

Radiation dose reduction in direct digital panoramic radiography

Objectives

(a) To measure the absorbed radiation doses at 16 anatomical sites of a Rando phantom and (b) to calculate the effective doses including and excluding the salivary gland doses in panoramic radiography using a conventional and a digital panoramic device.

Study design

Thermoluminescent dosimeters (TLD-100) were placed at 16 sites in a Rando phantom, using a conventional, Planmeca Promax and a digital, Planmeca PM2002CC Proline 2000 (Planmeca Oy, 00880 Helsinki, Finland) panoramic device for panoramic radiography. During conventional radiography the selected exposure settings were 66 kVp, 6 mA and 16 s, while during digital radiography two combinations were selected 60 kVp, 4 mA, 18 s and 66 kVp, 8 mA, 18 s with and without image processing function. The dosimeters were annealed in a PTW-TLDO Harshaw oven. TLD energy response was studied using RQN beam narrow series at GAEC's Secondary Standard Calibration Laboratory. The reader used was a Harshaw, 4500. Effective dose was estimated according to ICRP₆₀ report (E_ICRP60). An additional estimation of the effective dose was accomplished including the doses of the salivary glands (E_SAL). A Wilcoxon signed ranks test was used for statistical analysis.

Results

The effective dose, according to ICRP report (E_ICRP60) in conventional panoramic radiography was 17 μSv and E_SAL was 26 μSv. The respective values in digital panoramic radiography were E_ICRP60 = 23 μSv and E_SAL = 38 μSv; while using the lowest possible radiographic settings E_ICRP60 was 8 μSv and E_SAL was 12 μSv.

Conclusions

The effective dose reduction in digital panoramic radiography can be achieved, if the lowest possible radiographic settings are used.     

Effective and organ doses from scanography and zonography: a comparison with periapical radiography

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.     

Shielding effect of thyroid collar for digital panoramic radiography

Objectives:

To evaluate the shielding effect of thyroid collar for digital panoramic radiography.

Methods:

4 machines [Orthopantomograph^® OP200 (Instrumentarium Dental, Tuusula, Finland), Orthophos CD (Sirona Dental Systems GmbH, Bensheim, Germany), Orthophos XG Plus (Sirona Dental Systems GmbH) and ProMax^® (Planmeca Oy, Helsinki, Finland)] were used in this study. Average tissue-absorbed doses were measured using thermoluminescent dosemeter chips in an anthropomorphic phantom. Effective organ and total effective doses were derived according to the International Commission of Radiological Protection 2007 recommendations. The shielding effect of one collar in front and two collars both in front and at the back of the neck was measured.

Results:

The effective organ doses of the thyroid gland obtained from the 4 panoramic machines were 1.12 μSv for OP200, 2.71 μSv for Orthophos CD, 2.18 μSv for Orthophos XG plus and 2.20 μSv for ProMax, when no thyroid collar was used. When 1 collar was used in front of the neck, the effective organ doses of the thyroid gland were 1.01 μSv (9.8% reduction), 2.45 μSv (9.6% reduction), 1.76 μSv (19.3% reduction) and 1.70 μSv (22.7% reduction), respectively. Significant differences in dose reduction were found for Orthophos XG Plus and ProMax. When two collars were used, the effective organ doses of the thyroid gland were also significantly reduced for the two machines Orthophos XG Plus and ProMax. The same trend was observed in the total effective doses for the four machines.

Conclusions:

Wearing a thyroid collar was helpful when the direct digital panoramic imaging systems were in use, whereas for the indirect digital panoramic imaging systems, the thyroid collar did not have an extra protective effect on the thyroid gland and whole body.     

The effect of dose reduction on the detection of anatomical structures on panoramic radiographs

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.     

Comparison of indirect CsI/a:Si and direct a:Se digital radiography. An assessment of contrast and detail visualization

PURPOSE: To assess and quantify the image quality at two dose levels for an amorphous Silicon (a:Si) Cesium Iodide (CsI) flat panel system compared with a direct amorphous Selenium (a:Se) digital radiography system. MATERIAL AND METHODS: A contrast detectability test was performed employing the CDRAD-phantom at mAs-values leading to approximately equal phantom entrance doses of 41.4, 57.9, 75.1 and 120.8 micro Gy for the a:Se and 39.9, 58.4, 75.6 and 117.9 micro Gy for the CsI system. Images were presented to 4 independent observers. For quantitative comparison, the image quality figure (IQF) was calculated. Statistical analysis was performed using Pearson's correlation and the Wilcoxon test. A ROC-analysis was performed employing the TRG-phantom in a high- and a low-dose setting leading to entrance doses of 126.2 and 35 micro Gy for the direct, and 125.9 and 34.4 micro Gy for the indirect system. Statistical significance was evaluated using the Wilcoxon test. RESULTS: The flat panel a:Si digital system provided superior results compared with the a:Se drum digital system with respect to low-dose settings for CDRAD-phantom and ROC-analysis, ensuring a better image quality with respect to contrast and detail detectability. Higher-dose settings provided similar results for both systems. CONCLUSION: Image quality of a:Si flat panel digital radiography proved to be superior to a:Se drum digital radiography using low-dose settings. If the primary target is dose reduction indirect flat panel technology should be used.     

Dosimetry in dental radiology: comparison of spiral computerized tomography and orthopantomography]

INTRODUCTION: Dental diagnosis still depends largely on diagnostic imaging for correct anatomical and radiological assessment. Many studies confirm the risk of ionizing radiations, especially if used in pediatric populations and with suboptimal control. We compared the doses absorbed by the dentomaxillary area in Spiral CT and panoramic radiography examinations. MATERIAL AND METHODS: Doses were measured at critical organs in neck, ocular and intracranial regions with lithium fluoride dosimeters calibrated on the national standard and then positioned on an anthropomorphic Rando phantom made of tissue-equivalent material covering a skeleton. Multiple measurements were made during Spiral CT with the Dentascan software and panoramic radiography, to calculate mean absorbed doses for both examinations. Acquisition technical parameters were similar to those used in vivo. RESULTS: The parotid, cerebellum and thyroid gland were the most irradiated organs with panoramic radiography, with the addition of the mandible with Spiral CT. The gonads did not receive major doses. CONCLUSIONS: Our dose measurements demonstrate that patients receive smaller doses with panoramic radiography than with Spiral CT with Dentascan. After allowing for some variations from instrumental differences, they are in substantial agreement with literature data. Further investigations are needed considering the radiobiological risk related to the growing spread of Dentascan examinations.     

Digital panoramic radiography: a clinical survey

The application of digital panoramic radiography with photostimulable phosphors to dental diagnosis was evaluated in 500 patients. Comparative intraoral films of selected groups of teeth and electronic magnifications of the same portion of the arches were obtained in 63 cases. Digital images improved the quality of dental examinations compared with film radiographs. The possibility of contrast modulation was helpful to compensate for the different radiographic densities of the arches and to improve the visibility of gingival soft tissues. In addition, digital radiography reduced the radiation dose administered to the patient. The use of digital panoramic radiography is proposed as a substitute for film studies in all hospitals where a central unit for digital radiology is available. Correspondence to: R. Nessi     

A financial analysis of digital image acquisition for portable and table-top radiography.

The use of photostimulable phosphors as a method for obtaining digital radiographic images during traditional portable and table-top radiography has become a subject of increased interest and controversy in recent years. Proponents of this technology argue that a Picture Archival and Communications System--or PACS--is now within the grasp of most medical communities. However, there still exists concerns relating to the financial and economic effectiveness of this technological development. Does direct digital image acquisition during portable and table-top radiography present a financial benefit to the average health care facility? An in-depth financial analysis of the costs incurred by computed radiographic imaging provides sufficient information to state that financial benefits are a function of exposure-related repeat procedure volumes which can be reduced or eliminated through the use of this new technology. Repeat procedure volumes must be reduced by at least 6,000 procedures if the health care facility intends to avoid a financial loss from the use of photostimulable phosphor technology during portable and table-top radiography.     

Computed radiography: photostimulable phosphor image plate technology

Computed radiography is emerging as a digital imaging modality for use in conventional radiography. It is based on photostimulable phosphor image plate technology. The image plate (IP) is housed in a cassette similar to a standard radiographic cassette. The IP phosphor retains a latent image of the energy pattern to which it was exposed. This latent image is "read" as it is released from the phosphor by laser light exposure. The image is laser printed on 10 in x 14 in film.     

Diagnostic yield of conventional and digital cephalometric images: a human cadaver study

OBJECTIVES: To compare the clinical efficacy of digital and conventional cephalometric imaging. METHODS: Conventional and photostimulable phosphor cephalometric radiographs were obtained from three human cadavers at nine different exposure settings. Subjective image quality was assessed by six observers who evaluated six cephalometric landmarks. Organ doses were measured with TLDs and effective doses calculated. RESULTS: Compared with conventional cephalometric images, digital images had a consistently better subjective image quality for all exposure settings which was significant (P<0.05) for all but two. Organ doses were comparable. Higher kV and lower mAs settings yielded the lowest effective dose, which was highly dependent on the position of the thyroid gland in the beam. CONCLUSION: Relatively small variations in exposure settings do not influence subjective diagnostic image quality of digital cephalometric radiographs. Higher kV and lower mAs settings have the lowest effective dose and should therefore be preferred.     

Photostimulable phosphor digital radiography of the extremities: diagnostic accuracy compared with conventional radiography

A direct comparison was made between digital and conventional radiographs to assess the relative accuracy of a photostimulable phosphor digital imaging system in detecting and localizing minor trauma in the extremities. Matched sets of images were obtained on 103 patients who came to the emergency department for radiographs of the hand, wrist, foot, or ankle. One set was obtained with a conventional screen/film system. The other set was obtained with photostimulable phosphor digital cassettes. The two sets of images of each patient were independently interpreted by three radiologists in a blinded fashion. The findings of each of these three readers were compared with the consensus opinion of two different radiologists. Receiver-operating-characteristic (ROC) curves were plotted for each of the three readers, areas under the curves were calculated, and true-positive fractions were determined at false-positive fractions of 0.1. Although no significant differences in the areas under the ROC curves for the two imaging systems were detected, conventional radiography showed a slight advantage. However, when true-positive fractions for fracture detection were compared at false-positive fractions of 0.1 a statistically significant difference was shown, with conventional screen/film radiography being more sensitive. This study raises questions about the use of currently available photostimulable phosphor systems for imaging trauma of the extremities and suggests that those systems should not be used exclusively.     

Single-exposure dual-energy computed radiography: improved detection and processing

Recent reports have emphasized the potential for dual-energy computed radiographic applications. An improved method for single-exposure material-selective imaging with a photostimulable phosphor computed radiography system was investigated. The essential elements of the technique are (a) prefiltration with gadolinium, which divides the incident broad-beam x-ray spectrum into low-energy and high-energy peaks; (b) a cassette consisting of four photostimulable phosphor plates that record images of increasing mean energies, with a computed energy separation of 23 keV from the front to the rear plate; (c) spatially dependent scatter and beam-hardening corrections; and (d) a noise-reduction algorithm based on noise correlations between bone-selective and soft-tissue-selective dual-energy images. These elements result in improved material cancellation and signal-to-noise ratio throughout the image.     

Dosimetry of two extraoral direct digital imaging devices: NewTom cone beam CT and Orthophos Plus DS panoramic unit

OBJECTIVES: This study provides effective dose measurements for two extraoral direct digital imaging devices, the NewTom 9000 cone beam CT (CBCT) unit and the Orthophos Plus DS panoramic unit. METHODS: Thermoluminescent dosemeters were placed at 20 sites throughout the layers of the head and neck of a tissue-equivalent RANDO phantom. Variations in phantom orientation and beam collimation were used to create three different CBCT examination techniques: a combined maxillary and mandibular scan (Max/Man), a maxillary scan and a mandibular scan. Ten exposures for each technique were used to ensure a reliable measure of radiation from the dosemeters. Average tissue-absorbed dose, weighted equivalent dose and effective dose were calculated for each major anatomical site. Effective doses of individual organs were summed with salivary gland exposures (E(SAL)) and without salivary gland exposures (E(ICRP60)) to calculate two measures of whole-body effective dose. RESULTS: The effective doses for CBCT were: Max/Man scan, E(ICRP60)=36.3 micro Sv, E(SAL)=77.9 micro Sv; maxillary scan, E(ICRP60)=19.9 micro Sv, E(SAL)=41.5 micro Sv; and mandibular scan, E(ICRP60)=34.7 micro Sv, E(SAL)=74.7 micro Sv. Effective doses for the panoramic examination were E(ICRP60)=6.2 micro Sv and E(SAL)=22.0 micro Sv. CONCLUSION: When viewed in the context of potential diagnostic yield, the E(ICRP60) of 36.3 micro Sv for the NewTom compares favourably with published effective doses for conventional CT (314 micro Sv) and film tomography (2-9 micro Sv per image). CBCT examinations resulted in doses that were 3-7 (E(ICRP60)) and 2-4 (E(SAL)) times the panoramic doses observed in this study.     

Factors influencing the absorbed dose in intraoral radiography

OBJECTIVES: The aim of the present study was to find out whether it was more effective to achieve a dose reduction in intraoral radiography with an increase in the tube potential setting (and a decrease of milliampere seconds) by an additional attenuation of the X-ray beam behind the film plane or by the use of digital radiography. A second aim was to find out if there were differences between the integral doses determined by two different detectors and two different phantoms. METHODS: The X-ray attenuation in this in vitro study was carried out using additional lead foils from the dental film packet fixed behind the film plane and with a metal film holder. The dose measurements were performed with two semiconductor detectors (Quart, Diados). Patient simulation was achieved by the Alderson phantom or by the use of a filter (6Al+0.8Cu). The absorbed doses were calculated by integrating an exponential function between the entrance dose and the body exit dose. In addition, organ doses were measured and the effective dose was determined according to the Implementation of the 1990 Recommendations of the ICRP (ICRP-60). RESULTS: The increase in tube potential levels did not provide a substantial reduction of the absorbed dose (90 kVp instead of 60 kVp: reduction to 92.4%), only a reduction of the entrance dose (by 30% to 35% at 90 kVp compared with 60 kVp). The use of three lead foils behind the film plane instead of one resulted in a 14.0% reduction of the absorbed dose (60 kVp); the use of a metal film holder resulted in a 27.8% reduction (60 kVp). When tube potential settings were increased, the dose reduction decreased. The absorbed dose was reduced to 52% when a storage phosphor plate was used instead of a film (60 kVp). It was possible to determine the amount of dose reduction with both the calculated absorbed dose and the effective doses. The integral doses obtained from the Alderson phantom showed values 5% higher than those obtained by the filter (r(2)=96.7%). For the comparison of the integral doses, the measurements performed with Quart had values higher by a factor of 1.139 than those performed with Diados. CONCLUSIONS: Instead of increasing the tube voltage or using additional lead foils or metal film holders, a substantial dose reduction is provided by digital radiography or more sensitive films while a low tube potential level is maintained and the milliampere seconds setting is reduced.