|LETTER TO EDITOR
|Year : 2021 | Volume
| Issue : 2 | Page : 138-139
“Pseudo-polka dot” and “pseudo-corduroy” signs in osteoporotic spine
Sudhir Saxena, Sonal Saran, Swarnava Tarafdar, Tripti Prajapati
Department of Radio-Diagnosis, All India Institute of Medical Sciences, Rishikesh, Uttarakhand, India
|Date of Submission||27-Sep-2021|
|Date of Acceptance||19-Dec-2021|
|Date of Web Publication||09-Feb-2022|
Dr. Swarnava Tarafdar
Department of Radio-Diagnosis, All India Institute of Medical Sciences, Rishikesh - 249 203, Uttarakhand
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Saxena S, Saran S, Tarafdar S, Prajapati T. “Pseudo-polka dot” and “pseudo-corduroy” signs in osteoporotic spine. J Mahatma Gandhi Inst Med Sci 2021;26:138-9
|How to cite this URL:|
Saxena S, Saran S, Tarafdar S, Prajapati T. “Pseudo-polka dot” and “pseudo-corduroy” signs in osteoporotic spine. J Mahatma Gandhi Inst Med Sci [serial online] 2021 [cited 2022 May 24];26:138-9. Available from: https://www.jmgims.co.in/text.asp?2021/26/2/138/337439
We would like to highlight two important signs observed in computed tomography (CT) of the spine and designate them the “pseudo-polka dot” and “pseudo-Corduroy” signs. These signs are observed in the axial and sagittal sections of the CT spine, respectively, in vertebral bodies, and are due to prominent vertical trabecular pattern in diffuse osteoporosis. They may be important signs as they may be mistaken for vertebral hemangioma as closely resembles “polka dot” and “corduroy” signs in the axial and sagittal sections, respectively.
The “polka dot sign” is classical of hemangioma of the medullary cavity of the vertebral body where multiple high attenuation dots in a bone window or even in soft tissue window can simulate polka dot of clothing. This is due to thickened trabeculae which occur due to reinforcement of the osseous network adjacent to vascular channels in the hemangioma that have caused bone resorption. The same is the cause of the corduroy sign which is visualized in the sagittal section. This process usually occurs within fatty marrow. The vertebral hemangioma being the most common benign spinal lesion may involve the entire portion of the vertebral body at times or can be in multiple vertebral bodies.
On the other hand, osteoporosis is the most common metabolic bone disorder. The CT features of osteoporosis are diffusely increased radiolucency with a well-demarcated cortical rim and verticalization of the trabecular pattern. There is the prominence of vertical trabeculae with thinning of horizontal or secondary trabeculae of vertebral bodies. In axial and sagittal sections, budding radiologists may mistake it as “polka dot” and “corduroy” signs, respectively, due to their similar appearance. The features favoring osteoporosis are that it should be diffusely present in all vertebral bodies, while hemangioma will be focal and limited to one or a few vertebral bodies [Figure 1].
|Figure 1: Computed tomography spine axial section showing “pseudopolka dot” sign (upper left) and true “polka dot” sign (lower left). The sagittal image (right) confirms the condition as diffuse osteoporosis|
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The purpose of this article is not to discuss the “polka dot” or “corduroy” signs already discussed in several previous studies but to discuss two signs (“pseudo-polka dot” and “pseudo-Corduroy” signs) not discussed previously in any related articles. This will avoid misdiagnosing the most common benign vertebral body tumor from the most common metabolic bone disorder of the spine.
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Conflicts of interest
There are no conflicts of interest.
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