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Stair-step artifact seen in coronal and sagittal reformatted images because of misalignment of computed tomography tube, in a positron emission tomography/computed tomography scanner.

Jha AK, Shah S, Agrawal A, Purandare NC, Puranik AD, Rangarajan V - Indian J Nucl Med (2013)

Bottom Line: Reconstruction artifacts often affect the image quality.This pattern was corrected on realignment of CT tube.This artifact, popularly known as stair step artifact, is rarely cited in the literature and our case generates a practical scenario of how it affects the image quality and how it is corrected.

View Article: PubMed Central - PubMed

Affiliation: Department of Nuclear Medicine and Molecular Imaging, Tata Memorial Hospital, Parel, Mumbai, Maharashtra, India.

ABSTRACT
Reconstruction artifacts often affect the image quality. An unusual wavy imaging pattern was seen on computed tomography (CT) part of positron emission tomography/CT, on sagittal and coronal images. This pattern was corrected on realignment of CT tube. This artifact, popularly known as stair step artifact, is rarely cited in the literature and our case generates a practical scenario of how it affects the image quality and how it is corrected.

No MeSH data available.


Trans-axial computed tomography image showing no artifact
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Figure 4: Trans-axial computed tomography image showing no artifact

Mentions: We report a scenario in our department following the replacement of old CT tube with a new CT tube in our existing positron emission tomography (PET)/CT scanner, Discovery ST, GE Medical Systems, USA, by the service engineer. The machine was eventually handed over to us for clinical use and we started acquisition of the whole body PET/CT studies. When we scanned the first patient, we found wavy pattern in the subcutaneous and skin region on coronal [Figures 1b and 2a-arrows] as well as sagittal reformatted [Figures 1a, 3a-arrows] images. However, trans-axial image was completely normal and free of any artifact [Figure 4]. Hence, we immediately consulted the service engineer and asked about that abnormality found in the image. After discussion with departmental colleagues and service engineer, we decided to do the realignment of the CT tube. Service engineer realigned the CT tube and performed phantom imaging. We reconstructed the phantom image in all three planes. Wavy artifact observed in earlier image was not there in the phantom sagittal or coronal slices. Since much time had not elapsed after the first scan, we then decided to reacquire the whole body PET/CT study in the same acquisition parameter. Acquired image was reconstructed in coronal and sagittal slices and we found the wavy pattern was not there in the image [Figures 1c and d, 2b, 3b-arrows].


Stair-step artifact seen in coronal and sagittal reformatted images because of misalignment of computed tomography tube, in a positron emission tomography/computed tomography scanner.

Jha AK, Shah S, Agrawal A, Purandare NC, Puranik AD, Rangarajan V - Indian J Nucl Med (2013)

Trans-axial computed tomography image showing no artifact
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3822423&req=5

Figure 4: Trans-axial computed tomography image showing no artifact
Mentions: We report a scenario in our department following the replacement of old CT tube with a new CT tube in our existing positron emission tomography (PET)/CT scanner, Discovery ST, GE Medical Systems, USA, by the service engineer. The machine was eventually handed over to us for clinical use and we started acquisition of the whole body PET/CT studies. When we scanned the first patient, we found wavy pattern in the subcutaneous and skin region on coronal [Figures 1b and 2a-arrows] as well as sagittal reformatted [Figures 1a, 3a-arrows] images. However, trans-axial image was completely normal and free of any artifact [Figure 4]. Hence, we immediately consulted the service engineer and asked about that abnormality found in the image. After discussion with departmental colleagues and service engineer, we decided to do the realignment of the CT tube. Service engineer realigned the CT tube and performed phantom imaging. We reconstructed the phantom image in all three planes. Wavy artifact observed in earlier image was not there in the phantom sagittal or coronal slices. Since much time had not elapsed after the first scan, we then decided to reacquire the whole body PET/CT study in the same acquisition parameter. Acquired image was reconstructed in coronal and sagittal slices and we found the wavy pattern was not there in the image [Figures 1c and d, 2b, 3b-arrows].

Bottom Line: Reconstruction artifacts often affect the image quality.This pattern was corrected on realignment of CT tube.This artifact, popularly known as stair step artifact, is rarely cited in the literature and our case generates a practical scenario of how it affects the image quality and how it is corrected.

View Article: PubMed Central - PubMed

Affiliation: Department of Nuclear Medicine and Molecular Imaging, Tata Memorial Hospital, Parel, Mumbai, Maharashtra, India.

ABSTRACT
Reconstruction artifacts often affect the image quality. An unusual wavy imaging pattern was seen on computed tomography (CT) part of positron emission tomography/CT, on sagittal and coronal images. This pattern was corrected on realignment of CT tube. This artifact, popularly known as stair step artifact, is rarely cited in the literature and our case generates a practical scenario of how it affects the image quality and how it is corrected.

No MeSH data available.