Magnetic resonance imaging analysis and data collection

All images were transferred to a workstation (Advantage Windows version 4.2_07, GE Healthcare) and the DWI sequence was post-processed with commercial software (FuncTool, GE Healthcare) to obtain ADC maps (black/white and colour, the latter with a Puh-thallium colour scheme, ranging from black, diffusion restriction, to red, no diffusion restriction). The ADC maps of each lesion were calculated using four b-values (50, 400, 800, and 1000 s/mm²). The scanner software provided the mean value within the ROI, which equaled the ADC value (multiplied by 10^-3).

The MRI findings were re-evaluated by radiologists with 8 years of experience (BS) and 10 years of experience (EA) in musculoskeletal MRI, respectively. The signal characteristics, contrast enhancement patterns, locoregional distribution of the postoperative tissue areas, and suspicious lesions were evaluated. The haematoma, seroma, and areas of postsurgical or postradiotherapy soft tissue changes and the masses that may relapse were identified based on the study by Garner et al. according to the T1, T2, and contrasting patterns observed in the patients [6]. Lesions hyperintense in T1-weighted and T2-weighted images that did not demonstrate significant contrast enhancement following IV contrast administration were classified as haematoma (Figure 1A-​-D);D); lesions with hypointense signal characteristics in T1-weighted images and hyperintense in T2-weighted images that did not enhance with contrast after IV contrast administration or contrasted peripherally were classified as seroma (Figure 1E-​-H);H); areas with hypointense signal characteristics in T1-weighted images and hyperintense in T2-weighted images that were mildly enhanced with contrast after IV contrast administration were classified as changes after operation and radiotherapy (Figure 1I-​-L);L); and lesions that were T1 hypointense, T2 hyperintense, and enhanced with contrast after IV contrast administration were classified as potential recurrent masses (Figure 1M-​-P,P, Figure 2, Table 1). In diffusion-weighted images, 1 cm² ROIs were placed in postoperative tissue areas with hyperintense areas in T2-weighted images and 3 different areas with an appearance suspicious of recurrent masses, and the mean ADC values were calculated. ADC calculation was not done in the hypointense areas in T1-T2-weighted images and were considered as fibrosis. After MRI examinations, biopsies were obtained from the suspicious lesions with wire localization biopsies in 2 patients, and 13 patients underwent total excision. The mean diameter of the lesions excised was measured as 4.3 ± 1.5 cm (range 2-8 cm). Patients regarded as post-treatment tissue changes according to the T1, T2, and contrasting characteristics were followed up for a mean period of 17.8 ± 6.7 months (range, 8-32 months). No relapse or change in the tissue areas was identified during follow-up.

The magnetic resonance imaging (MRI) obtained at month 12 of the 48-year-old male patient operated with the diagnosis of liposarcoma in the thigh the lesion (A) hyperintense in T1-weighted images and (B) with hyperintense signal characteristics in T2-weighted images and (C) that did not demonstrate increased contrast enhancement after IV contrast administration was regarded as a haematoma (D). It was hyperintense in the diffusion weighted images, and the apparent diffusion coefficient (ADC) value was calculated as 2.5 × 10^-3 mm²/s in the ADC map (E-H). In the MRI of the 64-year-old female patient operated on with the diagnosis of a fibrosarcomas in the groin obtained at 8 months after surgery the lesion (E) with hypointense signal characteristics in T1-weighted images and (F) hyperintense in T2-weighted images and (G) that enhanced with contrast peripherally after IV contrast administration was regarded as a seroma (H) was hyperintense in diffusion weighted images and the ADC value was calculated as 3 × 10-3 mm²/s in the ADC map (I-L). In the elbow MRI obtained at the month 24 follow-up of a 42-year-old male patient operated because of a synovial sarcoma located in the antecubital area the areas (I) with hypointense signal characteristics and (J) hyperintense in T2-weighted images and (K) enhancing with contrast mildly after IV contrast administration were evaluated as post-treatment changes and (L) were hyperintense in diffusion-weighted images, and the ADC value was calculated as 2.8 × 10^-3 mm²/s in the ADC map (M-P). In the MRI follow up of a 34-year-old patient operated for a fibrosarcoma located in the superior of the shoulder obtained at month 12 after surgery the lesions (M) hypointense in T1-weighted images (N) hyperintense in T2-weighted images and (O) enhancing with contrast after IV contrast administration were primarily evaluated as recurrent masses and (P) were hyperintense in diffusion-weighted images, and the ADC value was calculated as 0.8 × 10^-3 mm²/s in the ADC map

In month 12 magnetic resonance imaging (MRI) follow-up of a 67-year-old patient operated for a liposarcoma located in the proximal of the groin the lesions (A) hypointense in T1-weighted images, (B) hyperintense in T2-weighted images and (C) that enhanced with contrast after IV contrast administration were primarily regarded as recurrent masses and (D) were hyperintense in diffusion weighted images and the ADC value was calculated as 1.3 × 10^-3 mm²/s in the apparent diffusion coefficient (ADC) map

Magnetic resonance imaging findings after treatment of soft-tissue sarcomas

¹Age dependent