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Effect of multi-planar CT image reformatting on surgeon diagnostic performance for localizing thoracolumbar disc extrusions in dogs.

King JB, Jones JC, Rossmeisl JH, Harper TA, Lanz OI, Werre SR - J. Vet. Sci. (2009)

Bottom Line: Frequencies were compared for MPR views rated most helpful.Diagnostic accuracy estimates were significantly greater for MPR vs. 2D CT images in one reader.Mean diagnostic certainty scores were significantly greater for MPR images in two readers.

View Article: PubMed Central - PubMed

Affiliation: Department of Clinical Sciences, School of Veterinary Medicine, University of California, Davis, California 95616, USA.

ABSTRACT
Accurate pre-operative localization and removal of disc material are important for minimizing morbidity in dogs with thoracolumbar disc extrusions. Computed tomography (CT) is an established technique for localizing disc extrusions in dogs, however the effect of multi-planar reformatting (MPR) on surgeon diagnostic performance has not been previously described. The purpose of this study was to test the effect of MPR CT on surgeon diagnostic accuracy, certainty and agreement for localizing thoracolumbar disc extrusions in dogs. Two veterinary surgeons and one veterinary neurologist who were unaware of surgical findings independently reviewed randomized sets of two-dimensional (2D) and MPR CT images from 111 dogs with confirmed thoracolumbar disc extrusions. For each set of images, readers recorded their localizations for extruded disc material and their diagnostic certainty. For MPR images, readers also recorded views they considered most helpful. Diagnostic accuracy estimates, mean diagnostic certainty scores and inter-observer agreement were compared using surgery as the gold standard. Frequencies were compared for MPR views rated most helpful. Diagnostic accuracy estimates were significantly greater for MPR vs. 2D CT images in one reader. Mean diagnostic certainty scores were significantly greater for MPR images in two readers. The change in agreement between 2D and MPR images differed from zero for all analyses (site, side, number affected) among all three readers. Multi-planar views rated most helpful with the highest frequency were oblique transverse and curved dorsal planar MPR views. Findings from this study indicate that multi-planar CT can improve surgeon diagnostic performance for localizing canine thoracolumbar disc extrusions.

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Related in: MedlinePlus

Examples of criteria used to assign numerical values for CT and surgical localizations for extruded disc material. The text ventral to vertebrae indicates the names assigned to anatomic locations. The numbers dorsal to vertebrae indicate the numerical scores that were assigned for those locations.
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Figure 4: Examples of criteria used to assign numerical values for CT and surgical localizations for extruded disc material. The text ventral to vertebrae indicates the names assigned to anatomic locations. The numbers dorsal to vertebrae indicate the numerical scores that were assigned for those locations.

Mentions: The first author compared CT localizations recorded on reader questionnaires with surgical localizations recorded in medical records. Lesions found in the region extending from the caudal 1/4 of the cranial vertebra to the cranial 1/4 of the caudal vertebra were defined as being located over an intervertebral disc space (Fig. 4). Lesions found in the middle 1/2 of the vertebral body were defined as being located over a vertebra. The site of each lesion was assigned to an arbitrary numbering system that was used for statistical analyses (Fig. 5). Starting at the T8-T9 disc space and ending with the L7-S1 disc space, a number from 1~13 was assigned to each adjacent disc space. Lesions located over vertebral bodies were assigned the cranial disc space's number and a 0.5 value. A reader's localization for CT lesion site was defined as "correct" if at least one of the sites identified by the reader was also identified in the surgical report. A reader's CT localization for lesion extent of involvement was defined as "correct" if it agreed with the cranio-caudal extent of the lesion described in the surgical report. No distinction was made if the reader identified more or fewer lesion sites than those reported at surgery. The reader's CT localization for the affected side (left, right, bilateral, mixed) was defined as "correct" if it agreed with the affected side in the surgical report.


Effect of multi-planar CT image reformatting on surgeon diagnostic performance for localizing thoracolumbar disc extrusions in dogs.

King JB, Jones JC, Rossmeisl JH, Harper TA, Lanz OI, Werre SR - J. Vet. Sci. (2009)

Examples of criteria used to assign numerical values for CT and surgical localizations for extruded disc material. The text ventral to vertebrae indicates the names assigned to anatomic locations. The numbers dorsal to vertebrae indicate the numerical scores that were assigned for those locations.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2801132&req=5

Figure 4: Examples of criteria used to assign numerical values for CT and surgical localizations for extruded disc material. The text ventral to vertebrae indicates the names assigned to anatomic locations. The numbers dorsal to vertebrae indicate the numerical scores that were assigned for those locations.
Mentions: The first author compared CT localizations recorded on reader questionnaires with surgical localizations recorded in medical records. Lesions found in the region extending from the caudal 1/4 of the cranial vertebra to the cranial 1/4 of the caudal vertebra were defined as being located over an intervertebral disc space (Fig. 4). Lesions found in the middle 1/2 of the vertebral body were defined as being located over a vertebra. The site of each lesion was assigned to an arbitrary numbering system that was used for statistical analyses (Fig. 5). Starting at the T8-T9 disc space and ending with the L7-S1 disc space, a number from 1~13 was assigned to each adjacent disc space. Lesions located over vertebral bodies were assigned the cranial disc space's number and a 0.5 value. A reader's localization for CT lesion site was defined as "correct" if at least one of the sites identified by the reader was also identified in the surgical report. A reader's CT localization for lesion extent of involvement was defined as "correct" if it agreed with the cranio-caudal extent of the lesion described in the surgical report. No distinction was made if the reader identified more or fewer lesion sites than those reported at surgery. The reader's CT localization for the affected side (left, right, bilateral, mixed) was defined as "correct" if it agreed with the affected side in the surgical report.

Bottom Line: Frequencies were compared for MPR views rated most helpful.Diagnostic accuracy estimates were significantly greater for MPR vs. 2D CT images in one reader.Mean diagnostic certainty scores were significantly greater for MPR images in two readers.

View Article: PubMed Central - PubMed

Affiliation: Department of Clinical Sciences, School of Veterinary Medicine, University of California, Davis, California 95616, USA.

ABSTRACT
Accurate pre-operative localization and removal of disc material are important for minimizing morbidity in dogs with thoracolumbar disc extrusions. Computed tomography (CT) is an established technique for localizing disc extrusions in dogs, however the effect of multi-planar reformatting (MPR) on surgeon diagnostic performance has not been previously described. The purpose of this study was to test the effect of MPR CT on surgeon diagnostic accuracy, certainty and agreement for localizing thoracolumbar disc extrusions in dogs. Two veterinary surgeons and one veterinary neurologist who were unaware of surgical findings independently reviewed randomized sets of two-dimensional (2D) and MPR CT images from 111 dogs with confirmed thoracolumbar disc extrusions. For each set of images, readers recorded their localizations for extruded disc material and their diagnostic certainty. For MPR images, readers also recorded views they considered most helpful. Diagnostic accuracy estimates, mean diagnostic certainty scores and inter-observer agreement were compared using surgery as the gold standard. Frequencies were compared for MPR views rated most helpful. Diagnostic accuracy estimates were significantly greater for MPR vs. 2D CT images in one reader. Mean diagnostic certainty scores were significantly greater for MPR images in two readers. The change in agreement between 2D and MPR images differed from zero for all analyses (site, side, number affected) among all three readers. Multi-planar views rated most helpful with the highest frequency were oblique transverse and curved dorsal planar MPR views. Findings from this study indicate that multi-planar CT can improve surgeon diagnostic performance for localizing canine thoracolumbar disc extrusions.

Show MeSH
Related in: MedlinePlus