Quantitative Analysis of Superb Microvascular Imaging versus Color-Coded Doppler Sonography for Preoperative Evaluation of Vascularization of Schwannomas

Abstract

Purpose Comparison of vascularization of schwannomas, benign peripheral nerve sheath tumors, using color-coded Doppler sonography (CCDS) and the Toshiba monochrome Superb Microvascular Imaging (mSMI) (Minato, Tokyo, Japan) technique. Methods In a retrospective single-center analysis, 16 patients were identified with histologically confirmed schwannomas. Between March and June 2018, all of them underwent ultrasonography using mSMI and CCDS before surgery. Schwannoma vascularization was quantitatively measured using ImageJ, an open platform for scientific image analysis. As the diagnostic gold standard, magnetic resonance imaging was mandatory. Results The mSMI and CCDS vascularization showed a moderate agreement between the techniques (κ = 0.5556; p = 0.0066). The quantitative visual assessment of the vascularization revealed no difference (25.3 ± 8.2 vs. 18.2 ± 3.8; p = 0.0532). Significant differences were found for the quantitative assessment of CCDS with ImageJ (26.8 ± 8.8 vs. 19.3 ± 2.8; p = 0.0368). However, in a subanalysis of highly vascularized schwannomas, mSMI revealed significant differences to slightly vascularized schwannomas (32.0 ± 8.2 vs. 21.3 ± 6.1; p = 0.0065) but not between moderately and slightly vascularized types (p = not significant). Conclusion The mSMI mode is qualitatively superior to conventional CCDS; however, quantitative analysis of the vascularization of schwannomas revealed no significant quantitative advantage for mSMI. Nevertheless, the mean ImageJ values showed a positive trend toward a better representation of the vascularization degree of schwannomas with mSMI.

Comparison of superb microvascular imaging (SMI) quantified with ImageJ to quantified contrast-enhanced ultrasound (qCEUS) in liver metastases—a pilot study

“…To the best of our knowledge there are also no systematic studies on brightness and flow rate for SMI-monochrome applications. The clinical benefit for daily practice or other indications of a possible application of mSMI quantification can currently still be assessed (33,(43)(44)(45).…”

“…In the mSMI mode, the parameters Doppler frequency, pulse repetition frequency, frame rate, and colour gain were set to the following mean settings during the study: 3.8 MHz [Doppler frequency], 8.6 kHz [pulse repetition frequency], frame rate >30 fps, and colour gain 35. According to current literature, mSMI values were classified as follows: no vascularisation (−), moderate vascularisation (+), and strong vascularisation (++) (32,33).…”

Advanced Ultrasound Techniques for Neuroimaging in Pediatric Critical Care: A Review

“…Methods of quantification for MVI, while not explored in depth in literature, can reflect those of color and power Doppler [ 37 , 38 , 39 , 40 ]. One proposed method of quantification involves the calculation of mean pixel grayscale intensity of a region of interest in a monochrome MVI image [ 41 ].…”

Quantitative Musculoskeletal Ultrasound

“…If the value resulted lower than the threshold, the pixel was considered as background; otherwise, it was considered a Doppler signal pixel. Kloth et al 82 used open source software ImageJ (Wayne Rasband, National Institutes of Health, Bethesda, MD, USA) to perform a quantitative evaluation of vascular signal detected in schwannomas using mSMI. Due to the subtraction of background information automatically performed by mSMI modality, software for Bmode data suppression was unnecessary.…”