Jornal Vascular Brasileiro
https://jvascbras.org/article/doi/10.1590/1677-5449.202200811
Jornal Vascular Brasileiro
Innovation

Pós-processamento da mediana de escala de cinza (GSM), posterização e remapeamento de cores para ultrassonografia de carótidas

Grayscale median (GSM) post-processing, posterizing, and color mapping for carotid ultrasound

Pedro Luciano Mellucci Filho; Matheus Bertanha; Rodrigo Gibin Jaldin; Winston Bonetti Yoshida; Marcone Lima Sobreira

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Resumo

Fatores relativos à placa aterosclerótica podem indicar instabilidade como ulcerações, hemorragias intraplaca, núcleo lipídico, capa fibrosa delgada ou irregular e inflamação. A mediana de escala de cinza (GSM, de greyscale median) da placa é um dos métodos mais difundidos de estudo da placa aterosclerótica; nesse sentido, é importante criar uma padronização da pós-processamento de forma compreensível. O pós-processamento foi realizado no software Photoshop 23.1.1. A padronização da imagem foi alcançada com o ajuste de curvas do histograma de escalas de cinza definindo o ponto mais escuro do lúmen vascular (sangue) para zero e a adventícia distal para 190. A posterização e o remapeamento de cores foram realizados. Um método que apresenta o atual estado da arte da técnica de forma acessível e ilustrativa pode contribuir para disseminação da análise de GSM. Neste artigo, esse processo é demonstrado passo a passo.

Palavras-chave

doenças das artérias carótidas, estenose das carótidas, ultrassonografia Doppler, pós-imagem, interpretação de imagem assistida por computador

Abstract

Factors related to atherosclerotic plaques may indicate instability, such as ulcerations, intraplaque hemorrhages, lipid core, thin or irregular fibrous cap, and inflammation. The grayscale median (GSM) value is one of the most widespread methods of studying atherosclerotic plaques and it is therefore important to comprehensively standardize image postprocessing. Post-processing was performed using Photoshop 23.1.1.202. Images were standardized by adjusting the grayscale histogram curves, setting the darkest point of the vascular lumen (blood) to zero and the distal adventitia to 190. Posterization and color mapping were performed. A methodology that presents the current state of the art in an accessible and illustrative way should contribute to the dissemination of GSM analysis. This article describes and illustrates the process step by step.

Keywords

carotid artery diseases; carotid stenosis; Doppler ultrasound; afterimage; computer-assisted image interpretation.

References

1 Barnett HJM, Taylor DW, Haynes RB, et al. Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis. N Engl J Med. 1991;325(7):445-53. http://dx.doi.org/10.1056/NEJM199108153250701. PMid:1852179.

2 Barnett HJ, Taylor DW, Eliasziw M, et al. Benefit of carotid endarterectomy in patients with symptomatic moderate or severe stenosis. N Engl J Med. 1998;339(20):1415-25. http://dx.doi.org/10.1056/NEJM199811123392002. PMid:9811916.

3 European Carotid Surgery Trialists’ Collaborative Group. Randomized trial of endarterectomy for recently symptomatic carotid stenosis: final results of the MRC European Carotid Surgery Trial (ECST). Lancet. 1998;351(9113):1379-87. http://dx.doi.org/10.1016/S0140-6736(97)09292-1. PMid:9593407.

4 Walker MD, Marler JR, Goldstein M, Grady PA, Toole JF, Baker WH. Executive Committee for the Asymptomatic Carotid Atherosclerosis Study: endarterectomy for asymptomatic patients with high grade stenosis. JAMA. 1995;273:1421-8. http://dx.doi.org/10.1001/jama.1995.03520420037035.

5 ACST Collaborators Group. The International Asymptomatic Carotid Surgery Trial (ACST). Lancet. 2004;363:1491-502.

6 Redgrave JNE, Lovett JK, Gallagher PJ, Rothwell PM. Histological assessment of 526 symptomatic carotid plaques in relation to the nature and timing of ischemic symptoms: the Oxford plaque study. Circulation. 2006;113(19):2320-8. http://dx.doi.org/10.1161/CIRCULATIONAHA.105.589044. PMid:16651471.

7 Nicolaides AN, Kakkos SK, Kyriacou E, et al. Asymptomatic internal carotid artery stenosis and cerebrovascular risk stratification. J Vasc Surg. 2010;52(6):1486-96.e1. http://dx.doi.org/10.1016/j.jvs.2010.07.021. PMid:21146746.

8 Oppi S, Nusser-Stein S, Blyszczuk P, et al. Macrophage NCOR1 protects from atherosclerosis by repressing a pro-atherogenic PPARγ signature. Eur Heart J. 2020;41(9):995-1005. http://dx.doi.org/10.1093/eurheartj/ehz667. PMid:31529020.

9 Jashari F, Ibrahimi P, Johansson E, Grönlund C, Wester P, Henein MY. Carotid IM-GSM is better than IMT for identifying patients with multiple arterial disease. Scand Cardiovasc J. 2018;52(2):93-9. http://dx.doi.org/10.1080/14017431.2018.1435903. PMid:29402147.

10 Östling G, Persson M, Hedblad B, Gonçalves I. Comparison of grey scale median (GSM) measurement in ultrasound images of human carotid plaques using two different softwares. Clin Physiol Funct Imaging. 2013;33(6):431-5. http://dx.doi.org/10.1111/cpf.12049. PMid:23701450.

11 Hashimoto H, Tagaya M, Niki H, Etani H. Computer-assisted analysis of heterogeneity on b-mode imaging predicts instability of asymptomatic carotid plaque. Cerebrovasc Dis. 2009;28(4):357-64. http://dx.doi.org/10.1159/000229554. PMid:19628937.

12 Pavela J, Ahanchi S, Steerman SN, Higgins JA, Panneton JM. Grayscale median analysis of primary stenosis and restenosis after carotid endarterectomy. J Vasc Surg. 2014;59(4):978-82. http://dx.doi.org/10.1016/j.jvs.2013.10.094. PMid:24361200.

13 Lal BK, Hobson RW 2nd, Pappas PR, et al. Pixel distribution analysis of B-mode ultrasound scan images predicts histologic features of atherosclerotic carotid plaques. J Vasc Surg. 2002;35(6):1210-7. http://dx.doi.org/10.1067/mva.2002.122888. PMid:12042733.

14 Græbe M, Sillesen H, Kjær A, Højgaard L. Carotid plaque imaging with FDG-PET and ultrasound. Imaging Med. 2011;3(1):17-30. http://dx.doi.org/10.2217/iim.10.72.

15 Steffel CN, Brown R, Korcarz CE, et al. Influence of ultrasound system and gain on grayscale median values. J Ultrasound Med. 2019;38(2):307-19. http://dx.doi.org/10.1002/jum.14690. PMid:30027550.

16 Engelhorn ALD, Engelhorn CA, Salles-Cunha SX. Initial evaluation of virtual histology ultrasonographic techniques applied to a case of renal transplant. J Vasc Ultrasound. 2015;39(3):142-4. http://dx.doi.org/10.1177/154431671503900305.

17 Sotomayor CG, Benjamens S, Dijkstra H, et al. Introduction of the grayscale median for ultrasound tissue characterization of the transplanted kidney. Diagnostics (Basel). 2021;11(3):390. http://dx.doi.org/10.3390/diagnostics11030390. PMid:33668900.
 


Submitted date:
08/07/2022

Accepted date:
12/02/2022

Sociedade Brasileira de Angiologia e Cirurgia Vascular (SBACV)"> Sociedade Brasileira de Angiologia e Cirurgia Vascular (SBACV)">
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