Preliminary Experience Using Dynamic MRI at 3.0 Tesla for Evaluation of Soft Tissue Tumors

Abstract

ObjectiveWe aimed to evaluate the use of dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) at 3.0 T for differentiating the benign from malignant soft tissue tumors. Also we aimed to assess whether the shorter length of DCE-MRI protocols are adequate, and to evaluate the effect of temporal resolution.Materials and MethodsDynamic contrast-enhanced magnetic resonance imaging, at 3.0 T with a 1 second temporal resolution in 13 patients with pathologically confirmed soft tissue tumors, was analyzed. Visual assessment of time-signal curves, subtraction images, maximal relative enhancement at the first (maximal peak enhancement [Emax]/1) and second (Emax/2) minutes, Emax, steepest slope calculated by using various time intervals (5, 30, 60 seconds), and the start of dynamic enhancement were analyzed.ResultsThe 13 tumors were comprised of seven benign and six malignant soft tissue neoplasms. Washout on time-signal curves was seen on three (50%) malignant tumors and one (14%) benign one. The most discriminating DCE-MRI parameter was the steepest slope calculated, by using at 5-second intervals, followed by Emax/1 and Emax/2. All of the steepest slope values occurred within 2 minutes of the dynamic study. Start of dynamic enhancement did not show a significant difference, but no malignant tumor rendered a value greater than 14 seconds.ConclusionThe steepest slope and early relative enhancement have the potential for differentiating benign from malignant soft tissue tumors. Short-length rather than long-length DCE-MRI protocol may be adequate for our purpose. The steepest slope parameters require a short temporal resolution, while maximal peak enhancement parameter may be more optimal for a longer temporal resolution.

Characterization of indeterminate soft tissue masses referred for biopsy: What is the added value of contrast imaging at 3.0 tesla?

“…Consequently, in patients with indeterminate STMs referred for biopsy, dynamic CE-MR sequences should be used, rather than static CE-MR alone. Several previous articles emphasized the role of dynamic contrast enhanced sequences to predict malignancy in STMs, [31][32][33][34][35][36] although these studies did not specifically address the "indeterminate" STM population, and none included DWI. Our data also confirm that the dynamic CE-MR sequence is an important technique to increase reader confidence for discriminating malignant and benign STMs.…”

Characteristics of Apparent Diffusion Coefficient and Time Intensity Curve in AdvancedMagnetic Resonance Imaging of Malignant Soft Tissue Tumors

“…The steepest slope graphmight help to differentiate benign and malignant soft tissue tumors. 14 A study found that the steepest slope increasefor >30% per minute was observed in 84% of malignant soft tissue tumors. 12 Malignant tumor has a high vascularization and a relatively limited interstitial space which results in a high rate of achieving the contrast-enhanced state.…”

“…A previous study found that 50% of the patients with malignant soft tissue tumor had type 4 TIC, 33% had type 3 TIC, 17% had type 2 TIC patients, and no patient had type 1 and type 5 TIC. 14 High perfusion and permeability of endothelial could be reflected withhigh enhancement intensity and contrast uptake in advanced MRI.The TIC type reflects dynamic changes in blood flow and intra-tumor perfusion. The pattern on TIC could suggest the physiology of tumor tissues, where this pattern can be used to determine the angiogenesis patterns the tumors.…”

“…The pattern on TIC could suggest the physiology of tumor tissues, where this pattern can be used to determine the angiogenesis patterns the tumors. 14 ADC is potentially to be used to differentiate benign and malignant soft tissue tumors. A study found that the mean of ADC of soft tissue tumorswas 0.90±0.70x10 -3 mm 2 /s and has been proven to be beneficial in differentiating benign and malignant tumors.…”

Imaging of Soft-Tissue Musculoskeletal Masses: Fundamental Concepts

“…Contrast-enhanced imaging is especially useful in assessment of hematomas or hemorrhagic lesions, in which enhanced imaging allows identification of a tumor nodule that might not otherwise be identified at nonenhanced conventional imaging. Subtraction imaging is a relatively recent innovation that has received little attention in the literature (17)(18)(19); however, we find it invaluable in such cases, since this technique eliminates the possibility of misinterpreting the T1 shortening associated with hemorrhagic change as vascular enhancement (Fig 13). It is also extremely useful in patients with metal fixation, because the subtraction technique eliminates the need for fat suppression at enhanced imaging (Fig 14).…”