Image quality vs radiation dose of four cone beam computed tomography scanners.

OBJECTIVES To evaluate image quality by examining segmentation accuracy and assess radiation dose for cone beam CT (CBCT) scanners. METHODS A skull phantom, scanned by a laser scanner, and a contrast phantom were used to evaluate segmentation accuracy. The contrast phantom consisted of a polymethyl methacrylate (PMMA) cylinder with cylindrical inserts of air, bone and PMMA. The phantoms were scanned on the (1) Accuitomo 3D, (2) MercuRay, (3) NewTom 3G, (4) i-CAT and (5) Sensation 16. The structures were segmented with an optimal threshold. Thicknesses of the bone of the mandible and the diameter of the cylinders in the contrast phantom were measured across lines at corresponding places in the CT image vs a ground truth. The accuracy was in the 95th percentile of the difference between corresponding measurements. The correlation between accuracy in skull and contrast phantom was calculated. The radiation dose was assessed by DPI(100,c) (dose profile integral (100,c)) at the central hole of a CT dose index (CTDI) phantom. RESULTS The results for the DPI(100,c) were 107 mGy mm for (1), 1569 mGy mm for (2), 446 mGy mm for (3), 249 mGy mm for (4) and 1090 mGy mm for (5). The segmentations in the contrast phantom were submillimeter accurate in all scanners. The segmentation accuracy of the mandible was 2.9 mm for (1), 4.2 mm for (2), 3.4 mm for (3), 1.0 mm for (4) and 1.2 mm for (5). The correlation between measurements in the contrast and skull phantom was below 0.37 mm. CONCLUSIONS The best radiation dose vs image quality was found for the i-CAT.

[1]  K. Zou,et al.  Multidetector CT of the paranasal sinus: potential for radiation dose reduction. , 2007, Radiology.

[2]  A. Wenzel,et al.  Cone beam CT and conventional tomography for the detection of morphological temporomandibular joint changes. , 2007, Dento maxillo facial radiology.

[3]  G. Marchal,et al.  Comparative study of image quality and radiation dose of MSCT and CBCT scanners in dentomaxillofacial radiology , 2007 .

[4]  H M Pinsky,et al.  Accuracy of three-dimensional measurements using cone-beam CT. , 2006, Dento maxillo facial radiology.

[5]  Robert L Dixon,et al.  Restructuring CT dosimetry-A realistic strategy for the future Requiem for the pencil chamber. , 2006, Medical physics.

[6]  S. Brooks,et al.  Dosimetry of 3 CBCT devices for oral and maxillofacial radiology: CB Mercuray, NewTom 3G and i-CAT. , 2006, Dento maxillo facial radiology.

[7]  Reinhilde Jacobs,et al.  Assessment of bone segmentation quality of CT scanners using laser scanning , 2006 .

[8]  Cynthia H McCollough,et al.  It is time to retire the computed tomography dose index (CTDI) for CT quality assurance and dose optimization. Against the proposition. , 2006, Medical physics.

[9]  Reinhilde Jacobs,et al.  State-of-the-art on cone beam CT imaging for preoperative planning of implant placement , 2006, Clinical Oral Investigations.

[10]  A. Farman,et al.  Clinical applications of cone-beam computed tomography in dental practice. , 2006, Journal.

[11]  K. Murase,et al.  Enlarged longitudinal dose profiles in cone-beam CT and the need for modified dosimetry. , 2005, Medical physics.

[12]  C. Lascala,et al.  Analysis of the accuracy of linear measurements obtained by cone beam computed tomography (CBCT-NewTom). , 2004, Dento maxillo facial radiology.

[13]  Robert L Dixon,et al.  A new look at CT dose measurement: beyond CTDI. , 2003, Medical physics.

[14]  André Gahleitner,et al.  Dental CT: imaging technique, anatomy, and pathologic conditions of the jaws , 2003, European Radiology.

[15]  M. Cohnen,et al.  Radiation dose in dental radiology , 2002, European Radiology.

[16]  Rafael Wiemker,et al.  Optimal thresholding for 3D segmentation of pulmonary nodules in high resolution CT , 2001, CARS.

[17]  C A Carlsson,et al.  Imaging modalities in x-ray computerized tomography and in selected volume tomography , 1999, Physics in medicine and biology.

[18]  Reinhilde Jacobs,et al.  Radiographic Planning and Assessment of Endosseous Oral Implants , 1998 .

[19]  Gerald Q. Maguire,et al.  Comparison and evaluation of retrospective intermodality brain image registration techniques. , 1997, Journal of computer assisted tomography.

[20]  Guy Marchal,et al.  Multimodality image registration by maximization of mutual information , 1997, IEEE Transactions on Medical Imaging.

[21]  D. Brenner.  It is time to retire the computed tomography dose index (CTDI) for CT quality assurance and dose optimization. For the proposition. , 2006, Medical physics.

[22]  S Hassfeld,et al.  Geometric accuracy of the NewTom 9000 Cone Beam CT. , 2005, Dento maxillo facial radiology.

[23]  W. Leitz,et al.  Computed Tomography Dose Assessment - A Practical Approach , 1995 .