Background High frequency linear probe ultrasound (US), besides allowing a better resolution in the gray scale (GS), is able to characterize colored images standards through a RGB image histogram1. These images develop through the information of additive primary colors, such as Red (R), Green (G) and Blue (B). On the other hand, the 3D US2 can better define the anatomical cuts, with more details, yielding more precise measures, together with the 2D US. These two methods are able to define echotextural damages, thus enhancing the detection of such changes in rheumatic diseases.
Objectives To detect echotextural damages through 2D and 3D US correlating these area and volumes measures.
Methods A total of 16 patients have been assessed (37.5% males and 62.5% females); 75% were affected by synovitis in their wrists, knees, metacarpophalangeal joint, distal interphalangeal joint, hips, ankle, metatarsophalangeal joint; 6.3% exhibited tenossynovitis, 6.3% tophus, 6.3% synovial cyst, 6.3% femoral-condyle cartilage, including 2 rheumatoid arthritis, 5 juvenile idiopathic arthritis, 4 gouts, 1 psoriatic arthritis, 2 osteoarthritis, 1 non-differentiated spondiloarthritis and 1 reactive arthropathy. A MyLab 50 -Esaote equipment was used with frequency transducer that ranged between 6.0 and 18.0 MHz for 2D, and with frequency that ranged from 10.0 to 12.0 MHz for 3D. A total of 630 images was obtained, 470 were in 2 D and 160 images in 3D. For each GS measurement there were 10 measures of 2D standard colored images as well as 3D correlation images of the original GS image, taken at different times in order not to remind prior measurements.
Results Average age 39.93±25.98 years of age; average measurement of 2D image area: (GS) 159.23±174.98 cm2, (Indigo) 126.86±156.98 cm2, (RGB) 117.78±142.71 cm2 and average measurement of 3D images 0.588±0.812 cm3. Correlations 2D: (GS) with (Indigo): r=0.948; p<0. 001; (GS) with (RGB) r=0.979; p<0. 001; (Indigo) with (RGB) r=0.987; p<0.001. Correlations 3D and 2D: (GS) r=0.757; p=0.001; (Indigo) r=0.758; p=0.002 and (RGB) r=0.764; p=0.001.
Conclusions The 2D colored image standards, together with 3D images, may improve the precision of the echotextural damage boundaries in rheumatologic diseases.
Marques Filho, O; Vieira Neto, H. Processamento Digital de Imagens, Rio de Janeiro: Brasport, 1999. ISBN8574520098.
Mendonça JA. O US Tridimensional (3D US). Ultrassonografia em Reumatologia: Uma Extensão do Exame Físico. Rio de Janeiro: Revinter, 2014. p. 70-76.
Disclosure of Interest None declared