ingest
cdrApp
2017-07-06T12:34:07.468Z
ccd64451-f0fc-4a42-94ad-226f4041fa4f
modifyDatastreamByValue
RELS-EXT
fedoraAdmin
2017-07-06T13:12:31.533Z
Setting exclusive relation
modifyDatastreamByValue
RELS-EXT
fedoraAdmin
2017-07-06T13:12:39.725Z
Setting exclusive relation
addDatastream
MD_TECHNICAL
fedoraAdmin
2017-07-06T13:12:47.706Z
Adding technical metadata derived by FITS
modifyDatastreamByValue
RELS-EXT
fedoraAdmin
2017-07-06T13:13:03.905Z
Setting exclusive relation
addDatastream
MD_FULL_TEXT
fedoraAdmin
2017-07-06T13:13:12.806Z
Adding full text metadata extracted by Apache Tika
modifyDatastreamByValue
RELS-EXT
fedoraAdmin
2017-07-06T13:13:22.100Z
Setting exclusive relation
modifyDatastreamByValue
RELS-EXT
cdrApp
2017-07-06T13:15:57.157Z
Setting exclusive relation
modifyDatastreamByValue
MD_DESCRIPTIVE
cdrApp
2018-01-25T12:24:39.785Z
modifyDatastreamByValue
MD_DESCRIPTIVE
cdrApp
2018-01-27T12:33:15.999Z
modifyDatastreamByValue
MD_DESCRIPTIVE
cdrApp
2018-02-28T19:56:33.793Z
modifyDatastreamByValue
MD_DESCRIPTIVE
cdrApp
2018-03-14T09:41:22.275Z
modifyDatastreamByValue
MD_DESCRIPTIVE
cdrApp
2018-05-17T21:14:14.314Z
modifyDatastreamByValue
MD_DESCRIPTIVE
cdrApp
2018-07-11T08:09:53.626Z
modifyDatastreamByValue
MD_DESCRIPTIVE
cdrApp
2018-07-18T04:19:21.039Z
modifyDatastreamByValue
MD_DESCRIPTIVE
cdrApp
2018-08-16T17:26:51.935Z
modifyDatastreamByValue
MD_DESCRIPTIVE
cdrApp
2018-09-27T13:12:17.274Z
modifyDatastreamByValue
MD_DESCRIPTIVE
cdrApp
2018-10-12T04:25:54.435Z
modifyDatastreamByValue
MD_DESCRIPTIVE
cdrApp
2019-03-21T14:03:42.576Z
Brittany
Kurzweg
Author
Oral and Maxillofacial Radiology Graduate Program
School of Dentistry
CBCT Image Quality Assessment Testing Clinically Relevant Volume Orientation and Position
Introduction and Objectives: Some physical measures of CBCT image quality correlate well with diagnostic image quality. Traditionally, these measures have been assessed in the center in a standard orientation. The purpose of this study was to test whether measures of image quality vary as a function of test tool location, orientation and dose. The second purpose was to determine if there was an association between objective and subjective image quality.
Methods: CBCT objective image quality was assessed with one standard and three modified phantoms using five fields of view. The test tool was located at the center of the phantom (standard), at the periphery (Mod1), angled and at the center (Mod2), or angled plane and at the periphery (Mod3). Phantoms were imaged with a Carestream CS 9300 CBCT scanner (Carestream, Rochester, NY), using SDSR (180-250µm voxel/90kVp/64mAs) and LDLR (400µm voxel/85kVp/14.5mAs) for each field-of-view. Contrast-to-noise ratio (CNR) and 10% modulation transfer function (MTF) were assessed in three repeated volumes. Data were analyzed using ANOVA and Tukey’s HSD. Subjective image quality was assessed with a pairwise comparison of anatomical landmarks corresponding to the test tool locations and orientations. Data were analyzed using logistic regression.
Results: CNR differed by phantom (p<0.0001) and dose (p<0.0001) for the 8x8 and 17x11 cm FOVs. Mod3 displayed significantly greater CNR than other phantoms. Low dose protocol provided higher CNR. MTF differed only by dose (p<0.0001) for the 8x8, 17x6, and 17x11 cm FOVs. SDSR provided higher MTF. Dose protocol was statistically significant for subjective image quality. Observers preferred images with higher MTF rather than higher CNR. Mod3 was negatively associated with observer preference. The 17x6cm FOV was positively associated with observer preference.
Conclusions: CNR improved for a peripherally positioned angled test tool (Mod3). Reduced kVp and larger voxels appear to counteract the effect of reduced mAs producing improved CNR at LDLR. Thus, image quality parameters are different at the center of a CBCT volume when compared to the periphery, depend on the orientation of the object, and vary as a function of kVp and voxel size. Observers preferred images with a higher MTF rather than higher CNR.
Spring 2017
2017
Information technology
CBCT, Digital Image analysis, Dose, Image Quality, Radiology
eng
Master of Science
Thesis
University of North Carolina at Chapel Hill Graduate School
Degree granting institution
Dentistry (Oral and Maxillofacial Radiology)
Andre
Mol
Thesis advisor
John
Ludlow
Thesis advisor
Marija
Ivanovic
Thesis advisor
text
Brittany
Kurzweg
Creator
Oral and Maxillofacial Radiology Graduate Program
School of Dentistry
CBCT Image Quality Assessment Testing Clinically Relevant Volume Orientation
and Position
Introduction and Objectives: Some physical measures of CBCT image quality
correlate well with diagnostic image quality. Traditionally, these measures have been
assessed in the center in a standard orientation. The purpose of this study was to test
whether measures of image quality vary as a function of test tool location, orientation
and dose. The second purpose was to determine if there was an association between
objective and subjective image quality. Methods: CBCT objective image quality was assessed
with one standard and three modified phantoms using five fields of view. The test tool was
located at the center of the phantom (standard), at the periphery (Mod1), angled and at
the center (Mod2), or angled plane and at the periphery (Mod3). Phantoms were imaged with
a Carestream CS 9300 CBCT scanner (Carestream, Rochester, NY), using SDSR (180-250µm
voxel/90kVp/64mAs) and LDLR (400µm voxel/85kVp/14.5mAs) for each field-of-view.
Contrast-to-noise ratio (CNR) and 10% modulation transfer function (MTF) were assessed in
three repeated volumes. Data were analyzed using ANOVA and Tukey’s HSD. Subjective image
quality was assessed with a pairwise comparison of anatomical landmarks corresponding to
the test tool locations and orientations. Data were analyzed using logistic regression.
Results: CNR differed by phantom (p<0.0001) and dose (p<0.0001) for the 8x8 and
17x11 cm FOVs. Mod3 displayed significantly greater CNR than other phantoms. Low dose
protocol provided higher CNR. MTF differed only by dose (p<0.0001) for the 8x8, 17x6,
and 17x11 cm FOVs. SDSR provided higher MTF. Dose protocol was statistically significant
for subjective image quality. Observers preferred images with higher MTF rather than
higher CNR. Mod3 was negatively associated with observer preference. The 17x6cm FOV was
positively associated with observer preference. Conclusions: CNR improved for a
peripherally positioned angled test tool (Mod3). Reduced kVp and larger voxels appear to
counteract the effect of reduced mAs producing improved CNR at LDLR. Thus, image quality
parameters are different at the center of a CBCT volume when compared to the periphery,
depend on the orientation of the object, and vary as a function of kVp and voxel size.
Observers preferred images with a higher MTF rather than higher CNR.
Spring 2017
2017
Information technology
CBCT, Digital Image analysis, Dose, Image Quality,
Radiology
eng
Master of Science
Thesis
University of North Carolina at Chapel Hill Graduate School
Degree granting
institution
Dentistry (Oral and Maxillofacial
Radiology)
Andre
Mol
Thesis advisor
John
Ludlow
Thesis advisor
Marija
Ivanovic
Thesis advisor
text
Brittany
Kurzweg
Creator
Oral and Maxillofacial Radiology Graduate Program
School of Dentistry
CBCT Image Quality Assessment Testing Clinically Relevant Volume Orientation and Position
Introduction and Objectives: Some physical measures of CBCT image quality correlate well with diagnostic image quality. Traditionally, these measures have been assessed in the center in a standard orientation. The purpose of this study was to test whether measures of image quality vary as a function of test tool location, orientation and dose. The second purpose was to determine if there was an association between objective and subjective image quality. Methods: CBCT objective image quality was assessed with one standard and three modified phantoms using five fields of view. The test tool was located at the center of the phantom (standard), at the periphery (Mod1), angled and at the center (Mod2), or angled plane and at the periphery (Mod3). Phantoms were imaged with a Carestream CS 9300 CBCT scanner (Carestream, Rochester, NY), using SDSR (180-250µm voxel/90kVp/64mAs) and LDLR (400µm voxel/85kVp/14.5mAs) for each field-of-view. Contrast-to-noise ratio (CNR) and 10% modulation transfer function (MTF) were assessed in three repeated volumes. Data were analyzed using ANOVA and Tukey’s HSD. Subjective image quality was assessed with a pairwise comparison of anatomical landmarks corresponding to the test tool locations and orientations. Data were analyzed using logistic regression. Results: CNR differed by phantom (p<0.0001) and dose (p<0.0001) for the 8x8 and 17x11 cm FOVs. Mod3 displayed significantly greater CNR than other phantoms. Low dose protocol provided higher CNR. MTF differed only by dose (p<0.0001) for the 8x8, 17x6, and 17x11 cm FOVs. SDSR provided higher MTF. Dose protocol was statistically significant for subjective image quality. Observers preferred images with higher MTF rather than higher CNR. Mod3 was negatively associated with observer preference. The 17x6cm FOV was positively associated with observer preference. Conclusions: CNR improved for a peripherally positioned angled test tool (Mod3). Reduced kVp and larger voxels appear to counteract the effect of reduced mAs producing improved CNR at LDLR. Thus, image quality parameters are different at the center of a CBCT volume when compared to the periphery, depend on the orientation of the object, and vary as a function of kVp and voxel size. Observers preferred images with a higher MTF rather than higher CNR.
Spring 2017
2017
Information technology
CBCT, Digital Image analysis, Dose, Image Quality, Radiology
eng
Master of Science
Thesis
University of North Carolina at Chapel Hill Graduate School
Degree granting institution
Dentistry (Oral and Maxillofacial Radiology)
Andre
Mol
Thesis advisor
John
Ludlow
Thesis advisor
Marija
Ivanovic
Thesis advisor
text
Brittany
Kurzweg
Creator
Oral and Maxillofacial Radiology Graduate Program
School of Dentistry
CBCT Image Quality Assessment Testing Clinically Relevant Volume Orientation and Position
Introduction and Objectives: Some physical measures of CBCT image quality correlate well with diagnostic image quality. Traditionally, these measures have been assessed in the center in a standard orientation. The purpose of this study was to test whether measures of image quality vary as a function of test tool location, orientation and dose. The second purpose was to determine if there was an association between objective and subjective image quality. Methods: CBCT objective image quality was assessed with one standard and three modified phantoms using five fields of view. The test tool was located at the center of the phantom (standard), at the periphery (Mod1), angled and at the center (Mod2), or angled plane and at the periphery (Mod3). Phantoms were imaged with a Carestream CS 9300 CBCT scanner (Carestream, Rochester, NY), using SDSR (180-250µm voxel/90kVp/64mAs) and LDLR (400µm voxel/85kVp/14.5mAs) for each field-of-view. Contrast-to-noise ratio (CNR) and 10% modulation transfer function (MTF) were assessed in three repeated volumes. Data were analyzed using ANOVA and Tukey’s HSD. Subjective image quality was assessed with a pairwise comparison of anatomical landmarks corresponding to the test tool locations and orientations. Data were analyzed using logistic regression. Results: CNR differed by phantom (p<0.0001) and dose (p<0.0001) for the 8x8 and 17x11 cm FOVs. Mod3 displayed significantly greater CNR than other phantoms. Low dose protocol provided higher CNR. MTF differed only by dose (p<0.0001) for the 8x8, 17x6, and 17x11 cm FOVs. SDSR provided higher MTF. Dose protocol was statistically significant for subjective image quality. Observers preferred images with higher MTF rather than higher CNR. Mod3 was negatively associated with observer preference. The 17x6cm FOV was positively associated with observer preference. Conclusions: CNR improved for a peripherally positioned angled test tool (Mod3). Reduced kVp and larger voxels appear to counteract the effect of reduced mAs producing improved CNR at LDLR. Thus, image quality parameters are different at the center of a CBCT volume when compared to the periphery, depend on the orientation of the object, and vary as a function of kVp and voxel size. Observers preferred images with a higher MTF rather than higher CNR.
Spring 2017
2017
Information technology
CBCT, Digital Image analysis, Dose, Image Quality, Radiology
eng
Master of Science
Thesis
University of North Carolina at Chapel Hill Graduate School
Degree granting institution
Dentistry (Oral and Maxillofacial Radiology)
Andre
Mol
Thesis advisor
John
Ludlow
Thesis advisor
Marija
Ivanovic
Thesis advisor
text
Brittany
Kurzweg
Creator
Oral and Maxillofacial Radiology Graduate Program
School of Dentistry
CBCT Image Quality Assessment Testing Clinically Relevant Volume Orientation and Position
Introduction and Objectives: Some physical measures of CBCT image quality correlate well with diagnostic image quality. Traditionally, these measures have been assessed in the center in a standard orientation. The purpose of this study was to test whether measures of image quality vary as a function of test tool location, orientation and dose. The second purpose was to determine if there was an association between objective and subjective image quality. Methods: CBCT objective image quality was assessed with one standard and three modified phantoms using five fields of view. The test tool was located at the center of the phantom (standard), at the periphery (Mod1), angled and at the center (Mod2), or angled plane and at the periphery (Mod3). Phantoms were imaged with a Carestream CS 9300 CBCT scanner (Carestream, Rochester, NY), using SDSR (180-250µm voxel/90kVp/64mAs) and LDLR (400µm voxel/85kVp/14.5mAs) for each field-of-view. Contrast-to-noise ratio (CNR) and 10% modulation transfer function (MTF) were assessed in three repeated volumes. Data were analyzed using ANOVA and Tukey’s HSD. Subjective image quality was assessed with a pairwise comparison of anatomical landmarks corresponding to the test tool locations and orientations. Data were analyzed using logistic regression. Results: CNR differed by phantom (p<0.0001) and dose (p<0.0001) for the 8x8 and 17x11 cm FOVs. Mod3 displayed significantly greater CNR than other phantoms. Low dose protocol provided higher CNR. MTF differed only by dose (p<0.0001) for the 8x8, 17x6, and 17x11 cm FOVs. SDSR provided higher MTF. Dose protocol was statistically significant for subjective image quality. Observers preferred images with higher MTF rather than higher CNR. Mod3 was negatively associated with observer preference. The 17x6cm FOV was positively associated with observer preference. Conclusions: CNR improved for a peripherally positioned angled test tool (Mod3). Reduced kVp and larger voxels appear to counteract the effect of reduced mAs producing improved CNR at LDLR. Thus, image quality parameters are different at the center of a CBCT volume when compared to the periphery, depend on the orientation of the object, and vary as a function of kVp and voxel size. Observers preferred images with a higher MTF rather than higher CNR.
2017-05
2017
Information technology
CBCT, Digital Image analysis, Dose, Image Quality, Radiology
eng
Master of Science
Masters Thesis
University of North Carolina at Chapel Hill Graduate School
Degree granting institution
Dentistry (Oral and Maxillofacial Radiology)
Andre
Mol
Thesis advisor
John
Ludlow
Thesis advisor
Marija
Ivanovic
Thesis advisor
text
Brittany
Kurzweg
Creator
Oral and Maxillofacial Radiology Graduate Program
School of Dentistry
CBCT Image Quality Assessment Testing Clinically Relevant Volume Orientation and Position
Introduction and Objectives: Some physical measures of CBCT image quality correlate well with diagnostic image quality. Traditionally, these measures have been assessed in the center in a standard orientation. The purpose of this study was to test whether measures of image quality vary as a function of test tool location, orientation and dose. The second purpose was to determine if there was an association between objective and subjective image quality. Methods: CBCT objective image quality was assessed with one standard and three modified phantoms using five fields of view. The test tool was located at the center of the phantom (standard), at the periphery (Mod1), angled and at the center (Mod2), or angled plane and at the periphery (Mod3). Phantoms were imaged with a Carestream CS 9300 CBCT scanner (Carestream, Rochester, NY), using SDSR (180-250µm voxel/90kVp/64mAs) and LDLR (400µm voxel/85kVp/14.5mAs) for each field-of-view. Contrast-to-noise ratio (CNR) and 10% modulation transfer function (MTF) were assessed in three repeated volumes. Data were analyzed using ANOVA and Tukey’s HSD. Subjective image quality was assessed with a pairwise comparison of anatomical landmarks corresponding to the test tool locations and orientations. Data were analyzed using logistic regression. Results: CNR differed by phantom (p<0.0001) and dose (p<0.0001) for the 8x8 and 17x11 cm FOVs. Mod3 displayed significantly greater CNR than other phantoms. Low dose protocol provided higher CNR. MTF differed only by dose (p<0.0001) for the 8x8, 17x6, and 17x11 cm FOVs. SDSR provided higher MTF. Dose protocol was statistically significant for subjective image quality. Observers preferred images with higher MTF rather than higher CNR. Mod3 was negatively associated with observer preference. The 17x6cm FOV was positively associated with observer preference. Conclusions: CNR improved for a peripherally positioned angled test tool (Mod3). Reduced kVp and larger voxels appear to counteract the effect of reduced mAs producing improved CNR at LDLR. Thus, image quality parameters are different at the center of a CBCT volume when compared to the periphery, depend on the orientation of the object, and vary as a function of kVp and voxel size. Observers preferred images with a higher MTF rather than higher CNR.
2017
Information technology
CBCT, Digital Image analysis, Dose, Image Quality, Radiology
eng
Master of Science
Masters Thesis
University of North Carolina at Chapel Hill Graduate School
Degree granting institution
Dentistry (Oral and Maxillofacial Radiology)
Andre
Mol
Thesis advisor
John
Ludlow
Thesis advisor
Marija
Ivanovic
Thesis advisor
text
2017-05
Brittany
Kurzweg
Creator
Oral and Maxillofacial Radiology Graduate Program
School of Dentistry
CBCT Image Quality Assessment Testing Clinically Relevant Volume Orientation and Position
Introduction and Objectives: Some physical measures of CBCT image quality correlate well with diagnostic image quality. Traditionally, these measures have been assessed in the center in a standard orientation. The purpose of this study was to test whether measures of image quality vary as a function of test tool location, orientation and dose. The second purpose was to determine if there was an association between objective and subjective image quality. Methods: CBCT objective image quality was assessed with one standard and three modified phantoms using five fields of view. The test tool was located at the center of the phantom (standard), at the periphery (Mod1), angled and at the center (Mod2), or angled plane and at the periphery (Mod3). Phantoms were imaged with a Carestream CS 9300 CBCT scanner (Carestream, Rochester, NY), using SDSR (180-250µm voxel/90kVp/64mAs) and LDLR (400µm voxel/85kVp/14.5mAs) for each field-of-view. Contrast-to-noise ratio (CNR) and 10% modulation transfer function (MTF) were assessed in three repeated volumes. Data were analyzed using ANOVA and Tukey’s HSD. Subjective image quality was assessed with a pairwise comparison of anatomical landmarks corresponding to the test tool locations and orientations. Data were analyzed using logistic regression. Results: CNR differed by phantom (p<0.0001) and dose (p<0.0001) for the 8x8 and 17x11 cm FOVs. Mod3 displayed significantly greater CNR than other phantoms. Low dose protocol provided higher CNR. MTF differed only by dose (p<0.0001) for the 8x8, 17x6, and 17x11 cm FOVs. SDSR provided higher MTF. Dose protocol was statistically significant for subjective image quality. Observers preferred images with higher MTF rather than higher CNR. Mod3 was negatively associated with observer preference. The 17x6cm FOV was positively associated with observer preference. Conclusions: CNR improved for a peripherally positioned angled test tool (Mod3). Reduced kVp and larger voxels appear to counteract the effect of reduced mAs producing improved CNR at LDLR. Thus, image quality parameters are different at the center of a CBCT volume when compared to the periphery, depend on the orientation of the object, and vary as a function of kVp and voxel size. Observers preferred images with a higher MTF rather than higher CNR.
2017
Information technology
CBCT, Digital Image analysis, Dose, Image Quality, Radiology
eng
Master of Science
Masters Thesis
University of North Carolina at Chapel Hill Graduate School
Degree granting institution
Dentistry (Oral and Maxillofacial Radiology)
Andre
Mol
Thesis advisor
John
Ludlow
Thesis advisor
Marija
Ivanovic
Thesis advisor
text
2017-05
Brittany
Kurzweg
Creator
Oral and Maxillofacial Radiology Graduate Program
School of Dentistry
CBCT Image Quality Assessment Testing Clinically Relevant Volume Orientation and Position
Introduction and Objectives: Some physical measures of CBCT image quality correlate well with diagnostic image quality. Traditionally, these measures have been assessed in the center in a standard orientation. The purpose of this study was to test whether measures of image quality vary as a function of test tool location, orientation and dose. The second purpose was to determine if there was an association between objective and subjective image quality. Methods: CBCT objective image quality was assessed with one standard and three modified phantoms using five fields of view. The test tool was located at the center of the phantom (standard), at the periphery (Mod1), angled and at the center (Mod2), or angled plane and at the periphery (Mod3). Phantoms were imaged with a Carestream CS 9300 CBCT scanner (Carestream, Rochester, NY), using SDSR (180-250µm voxel/90kVp/64mAs) and LDLR (400µm voxel/85kVp/14.5mAs) for each field-of-view. Contrast-to-noise ratio (CNR) and 10% modulation transfer function (MTF) were assessed in three repeated volumes. Data were analyzed using ANOVA and Tukey’s HSD. Subjective image quality was assessed with a pairwise comparison of anatomical landmarks corresponding to the test tool locations and orientations. Data were analyzed using logistic regression. Results: CNR differed by phantom (p<0.0001) and dose (p<0.0001) for the 8x8 and 17x11 cm FOVs. Mod3 displayed significantly greater CNR than other phantoms. Low dose protocol provided higher CNR. MTF differed only by dose (p<0.0001) for the 8x8, 17x6, and 17x11 cm FOVs. SDSR provided higher MTF. Dose protocol was statistically significant for subjective image quality. Observers preferred images with higher MTF rather than higher CNR. Mod3 was negatively associated with observer preference. The 17x6cm FOV was positively associated with observer preference. Conclusions: CNR improved for a peripherally positioned angled test tool (Mod3). Reduced kVp and larger voxels appear to counteract the effect of reduced mAs producing improved CNR at LDLR. Thus, image quality parameters are different at the center of a CBCT volume when compared to the periphery, depend on the orientation of the object, and vary as a function of kVp and voxel size. Observers preferred images with a higher MTF rather than higher CNR.
2017
Information technology
CBCT, Digital Image analysis, Dose, Image Quality, Radiology
eng
Master of Science
Masters Thesis
University of North Carolina at Chapel Hill Graduate School
Degree granting institution
Dentistry (Oral and Maxillofacial Radiology)
Andre
Mol
Thesis advisor
John
Ludlow
Thesis advisor
Marija
Ivanovic
Thesis advisor
text
2017-05
Brittany
Kurzweg
Creator
Oral and Maxillofacial Radiology Graduate Program
School of Dentistry
CBCT Image Quality Assessment Testing Clinically Relevant Volume Orientation and Position
Introduction and Objectives: Some physical measures of CBCT image quality correlate well with diagnostic image quality. Traditionally, these measures have been assessed in the center in a standard orientation. The purpose of this study was to test whether measures of image quality vary as a function of test tool location, orientation and dose. The second purpose was to determine if there was an association between objective and subjective image quality. Methods: CBCT objective image quality was assessed with one standard and three modified phantoms using five fields of view. The test tool was located at the center of the phantom (standard), at the periphery (Mod1), angled and at the center (Mod2), or angled plane and at the periphery (Mod3). Phantoms were imaged with a Carestream CS 9300 CBCT scanner (Carestream, Rochester, NY), using SDSR (180-250µm voxel/90kVp/64mAs) and LDLR (400µm voxel/85kVp/14.5mAs) for each field-of-view. Contrast-to-noise ratio (CNR) and 10% modulation transfer function (MTF) were assessed in three repeated volumes. Data were analyzed using ANOVA and Tukey’s HSD. Subjective image quality was assessed with a pairwise comparison of anatomical landmarks corresponding to the test tool locations and orientations. Data were analyzed using logistic regression. Results: CNR differed by phantom (p<0.0001) and dose (p<0.0001) for the 8x8 and 17x11 cm FOVs. Mod3 displayed significantly greater CNR than other phantoms. Low dose protocol provided higher CNR. MTF differed only by dose (p<0.0001) for the 8x8, 17x6, and 17x11 cm FOVs. SDSR provided higher MTF. Dose protocol was statistically significant for subjective image quality. Observers preferred images with higher MTF rather than higher CNR. Mod3 was negatively associated with observer preference. The 17x6cm FOV was positively associated with observer preference. Conclusions: CNR improved for a peripherally positioned angled test tool (Mod3). Reduced kVp and larger voxels appear to counteract the effect of reduced mAs producing improved CNR at LDLR. Thus, image quality parameters are different at the center of a CBCT volume when compared to the periphery, depend on the orientation of the object, and vary as a function of kVp and voxel size. Observers preferred images with a higher MTF rather than higher CNR.
2017
Information technology
CBCT, Digital Image analysis, Dose, Image Quality, Radiology
eng
Master of Science
Masters Thesis
Dentistry (Oral and Maxillofacial Radiology)
André
Mol
Thesis advisor
John B.
Ludlow
Thesis advisor
Marija
Ivanovic
Thesis advisor
text
2017-05
University of North Carolina at Chapel Hill
Degree granting institution
Brittany
Kurzweg
Creator
Oral and Maxillofacial Radiology Graduate Program
School of Dentistry
CBCT Image Quality Assessment Testing Clinically Relevant Volume Orientation and Position
Introduction and Objectives: Some physical measures of CBCT image quality correlate well with diagnostic image quality. Traditionally, these measures have been assessed in the center in a standard orientation. The purpose of this study was to test whether measures of image quality vary as a function of test tool location, orientation and dose. The second purpose was to determine if there was an association between objective and subjective image quality. Methods: CBCT objective image quality was assessed with one standard and three modified phantoms using five fields of view. The test tool was located at the center of the phantom (standard), at the periphery (Mod1), angled and at the center (Mod2), or angled plane and at the periphery (Mod3). Phantoms were imaged with a Carestream CS 9300 CBCT scanner (Carestream, Rochester, NY), using SDSR (180-250µm voxel/90kVp/64mAs) and LDLR (400µm voxel/85kVp/14.5mAs) for each field-of-view. Contrast-to-noise ratio (CNR) and 10% modulation transfer function (MTF) were assessed in three repeated volumes. Data were analyzed using ANOVA and Tukey’s HSD. Subjective image quality was assessed with a pairwise comparison of anatomical landmarks corresponding to the test tool locations and orientations. Data were analyzed using logistic regression. Results: CNR differed by phantom (p<0.0001) and dose (p<0.0001) for the 8x8 and 17x11 cm FOVs. Mod3 displayed significantly greater CNR than other phantoms. Low dose protocol provided higher CNR. MTF differed only by dose (p<0.0001) for the 8x8, 17x6, and 17x11 cm FOVs. SDSR provided higher MTF. Dose protocol was statistically significant for subjective image quality. Observers preferred images with higher MTF rather than higher CNR. Mod3 was negatively associated with observer preference. The 17x6cm FOV was positively associated with observer preference. Conclusions: CNR improved for a peripherally positioned angled test tool (Mod3). Reduced kVp and larger voxels appear to counteract the effect of reduced mAs producing improved CNR at LDLR. Thus, image quality parameters are different at the center of a CBCT volume when compared to the periphery, depend on the orientation of the object, and vary as a function of kVp and voxel size. Observers preferred images with a higher MTF rather than higher CNR.
2017
Information technology
CBCT; Digital Image analysis; Dose; Image Quality; Radiology
eng
Master of Science
Masters Thesis
Dentistry (Oral and Maxillofacial Radiology)
André
Mol
Thesis advisor
John B.
Ludlow
Thesis advisor
Marija
Ivanovic
Thesis advisor
text
2017-05
University of North Carolina at Chapel Hill
Degree granting institution
Brittany
Kurzweg
Creator
Oral and Maxillofacial Radiology Graduate Program
School of Dentistry
CBCT Image Quality Assessment Testing Clinically Relevant Volume Orientation and Position
Introduction and Objectives: Some physical measures of CBCT image quality correlate well with diagnostic image quality. Traditionally, these measures have been assessed in the center in a standard orientation. The purpose of this study was to test whether measures of image quality vary as a function of test tool location, orientation and dose. The second purpose was to determine if there was an association between objective and subjective image quality. Methods: CBCT objective image quality was assessed with one standard and three modified phantoms using five fields of view. The test tool was located at the center of the phantom (standard), at the periphery (Mod1), angled and at the center (Mod2), or angled plane and at the periphery (Mod3). Phantoms were imaged with a Carestream CS 9300 CBCT scanner (Carestream, Rochester, NY), using SDSR (180-250µm voxel/90kVp/64mAs) and LDLR (400µm voxel/85kVp/14.5mAs) for each field-of-view. Contrast-to-noise ratio (CNR) and 10% modulation transfer function (MTF) were assessed in three repeated volumes. Data were analyzed using ANOVA and Tukey’s HSD. Subjective image quality was assessed with a pairwise comparison of anatomical landmarks corresponding to the test tool locations and orientations. Data were analyzed using logistic regression. Results: CNR differed by phantom (p<0.0001) and dose (p<0.0001) for the 8x8 and 17x11 cm FOVs. Mod3 displayed significantly greater CNR than other phantoms. Low dose protocol provided higher CNR. MTF differed only by dose (p<0.0001) for the 8x8, 17x6, and 17x11 cm FOVs. SDSR provided higher MTF. Dose protocol was statistically significant for subjective image quality. Observers preferred images with higher MTF rather than higher CNR. Mod3 was negatively associated with observer preference. The 17x6cm FOV was positively associated with observer preference. Conclusions: CNR improved for a peripherally positioned angled test tool (Mod3). Reduced kVp and larger voxels appear to counteract the effect of reduced mAs producing improved CNR at LDLR. Thus, image quality parameters are different at the center of a CBCT volume when compared to the periphery, depend on the orientation of the object, and vary as a function of kVp and voxel size. Observers preferred images with a higher MTF rather than higher CNR.
2017
Information technology
CBCT, Digital Image analysis, Dose, Image Quality, Radiology
eng
Master of Science
Masters Thesis
University of North Carolina at Chapel Hill Graduate School
Degree granting institution
Dentistry (Oral and Maxillofacial Radiology)
André
Mol
Thesis advisor
John B.
Ludlow
Thesis advisor
Marija
Ivanovic
Thesis advisor
text
2017-05
Brittany
Kurzweg
Creator
Oral and Maxillofacial Radiology Graduate Program
School of Dentistry
CBCT Image Quality Assessment Testing Clinically Relevant Volume Orientation and Position
Introduction and Objectives: Some physical measures of CBCT image quality correlate well with diagnostic image quality. Traditionally, these measures have been assessed in the center in a standard orientation. The purpose of this study was to test whether measures of image quality vary as a function of test tool location, orientation and dose. The second purpose was to determine if there was an association between objective and subjective image quality. Methods: CBCT objective image quality was assessed with one standard and three modified phantoms using five fields of view. The test tool was located at the center of the phantom (standard), at the periphery (Mod1), angled and at the center (Mod2), or angled plane and at the periphery (Mod3). Phantoms were imaged with a Carestream CS 9300 CBCT scanner (Carestream, Rochester, NY), using SDSR (180-250µm voxel/90kVp/64mAs) and LDLR (400µm voxel/85kVp/14.5mAs) for each field-of-view. Contrast-to-noise ratio (CNR) and 10% modulation transfer function (MTF) were assessed in three repeated volumes. Data were analyzed using ANOVA and Tukey’s HSD. Subjective image quality was assessed with a pairwise comparison of anatomical landmarks corresponding to the test tool locations and orientations. Data were analyzed using logistic regression. Results: CNR differed by phantom (p<0.0001) and dose (p<0.0001) for the 8x8 and 17x11 cm FOVs. Mod3 displayed significantly greater CNR than other phantoms. Low dose protocol provided higher CNR. MTF differed only by dose (p<0.0001) for the 8x8, 17x6, and 17x11 cm FOVs. SDSR provided higher MTF. Dose protocol was statistically significant for subjective image quality. Observers preferred images with higher MTF rather than higher CNR. Mod3 was negatively associated with observer preference. The 17x6cm FOV was positively associated with observer preference. Conclusions: CNR improved for a peripherally positioned angled test tool (Mod3). Reduced kVp and larger voxels appear to counteract the effect of reduced mAs producing improved CNR at LDLR. Thus, image quality parameters are different at the center of a CBCT volume when compared to the periphery, depend on the orientation of the object, and vary as a function of kVp and voxel size. Observers preferred images with a higher MTF rather than higher CNR.
2017
Information technology
CBCT; Digital Image analysis; Dose; Image Quality; Radiology
eng
Master of Science
Masters Thesis
University of North Carolina at Chapel Hill Graduate School
Degree granting institution
André
Mol
Thesis advisor
John B.
Ludlow
Thesis advisor
Marija
Ivanovic
Thesis advisor
text
2017-05
Kurzweg_unc_0153M_16976.pdf
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2017-04-28T16:48:42Z
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