MRI to differentiate benign from malignant soft-tissue tumours of the extremities: a simplified systematic imaging approach using depth, size and heterogeneity of signal intensity

Wj, Chung; Chung, Hwan; Mj, Shin; Sh, Lee; Mh, Lee; Js, Lee; Kim, Do Young; Lee, WK

doi:10.1259/bjr/27487871

Cited by 73 publications

(64 citation statements)

References 16 publications

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“…Traditionally, a combination of patient demographic information, especially age, and imaging features are used to attempt to characterize lesions on the benign-malignant spectrum. Features such as large lesion size and greater depth, irregular margin, heterogeneity, and invasion of local structures, along with absence of deinitely benign features (eg, purely cystic), are regarded as concerning (1,5,6).…”

mentioning

confidence: 99%

Shear-Wave Elastography of Benign versus Malignant Musculoskeletal Soft-Tissue Masses: Comparison with Conventional US and MRI

Tavare¹,

Alfuraih²,

Hensor³

et al. 2019

Radiology

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To examine if shear-wave elastography (SWE) improves the accuracy of diagnosing soft-tissue masses as benign or malignant compared with US alone or in combination with MRI. Materials and Methods: Two hundred six consecutive adult participants (mean age, 57.7 years; range, 18-91 years), including 89 men (median age, 56.0 years; range, 21-91 years) and 117 women (median age, 59.1 years; range, 18-88 years), who were referred for biopsy of a soft-tissue mass were prospectively recruited from December 2015 through March 2017. Participants underwent B-mode US, MRI, and SWE prior to biopsy. hree musculoskeletal radiologists independently reviewed US images alone, followed by US and MRI images together, and classiied lesions as benign, probably benign, probably malignant, or malignant. For SWE, the area under the receiver operating characteristic (ROC) curve (AUC) was calculated for transverse shear-wave velocity (SWV). Multivariable logistic regression was used to investigate the association between SWE and malignancy alongside individual demographic and imaging variables. Results: At histologic examination, 79 of 206 (38%) participants had malignant lesions. SWV showed good diagnostic accuracy for lesions classiied as benign or probably benign by US alone (AUC = 0.87 [95% conidence interval {CI}: 0.79, 0.95]). SWV did not provide substantive diagnostic information for lesions classiied as probably malignant or malignant, whether the classiication was made with or without MRI. However, multivariable modeling indicated that diagnostic accuracy may vary by lesion position (interaction P = .

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confidence: 99%

Shear-Wave Elastography of Benign versus Malignant Musculoskeletal Soft-Tissue Masses: Comparison with Conventional US and MRI

Tavare¹,

Alfuraih²,

Hensor³

et al. 2019

Radiology

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“…In conventional proton MRI, T 2 is an important biomarker to discriminate tumor from healthy tissue, aiding in diagnosis and disease prognosis. However, MRI focuses on morphological changes whilst metabolic changes occur prior to any observable structural alterations, creating opportunities for MRSI . T 2 contrast in MRSI, however, is still not available in the clinic but may increase insight into diseases when used as a biomarker including relaxation information for each metabolite separately.…”

Section: Discussionmentioning

confidence: 91%

“…However, MRI focuses on morphological changes whilst metabolic changes occur prior to any observable structural alterations, creating opportunities for MRSI. 26,27 In our T 1 -weighted 31 P MRSI focusing on P i , we choose two T R and flip angle combinations, which remained close to and deviated from the optimal Ernst angle condition for cytosolic P i , allowing for T 1 weighting with the latter condition. Other metabolites are T 1 weighted in both situations; however, the weighting is amplified for PCr, PME and PDE, with T 1 relaxation rates of the order of several seconds (≥3.1 s), whereas the optimal Ernst angle condition is almost met for the βand γ-ATP resonances, with T 1 relaxation rates of around 1800 ms in the high flip angle experiment.…”

Section: Resultsmentioning

confidence: 99%

Low SAR ³¹P (multi‐echo) spectroscopic imaging using an integrated whole‐body transmit coil at 7T

et al. 2019

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Phosphorus (31P) MRSI provides opportunities to monitor potential biomarkers. However, current applications of 31P MRS are generally restricted to relatively small volumes as small coils are used. Conventional surface coils require high energy adiabatic RF pulses to achieve flip angle homogeneity, leading to high specific absorption rates (SARs), and occupy space within the MRI bore. A birdcage coil behind the bore cover can potentially reduce the SAR constraints massively by use of conventional amplitude modulated pulses without sacrificing patient space. Here, we demonstrate that the integrated 31P birdcage coil setup with a high power RF amplifier at 7 T allows for low flip angle excitations with short repetition time (T R) for fast 3D chemical shift imaging (CSI) and 3D T 1‐weighted CSI as well as high flip angle multi‐refocusing pulses, enabling multi‐echo CSI that can measure metabolite T 2, over a large field of view in the body. B 1 + calibration showed a variation of only 30% in maximum B 1 in four volunteers. High signal‐to‐noise ratio (SNR) MRSI was obtained in the gluteal muscle using two fast in vivo 3D spectroscopic imaging protocols, with low and high flip angles, and with multi‐echo MRSI without exceeding SAR levels. In addition, full liver MRSI was achieved within SAR constraints. The integrated 31P body coil allowed for fast spectroscopic imaging and successful implementation of the multi‐echo method in the body at 7 T. Moreover, no additional enclosing hardware was needed for 31P excitation, paving the way to include larger subjects and more space for receiver arrays. The increase in possible number of RF excitations per scan time, due to the improved B 1 + homogeneity and low SAR, allows SNR to be exchanged for spatial resolution in CSI and/or T 1 weighting by simply manipulating T R and/or flip angle to detect and quantify ratios from different molecular species.

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“…Unfortunately, most of the industry MRI recommendations are based on in vitro testing of homogenous tissue and phantom models. Homogenous models are commonly used for modeling malignant tumors, but do not accurately predict the SAR distribution within the heterogeneous distribution of tissues with varying electrical properties . Ullman and colleagues conducted a literature review of the DBS Brain Tissue Network for MRI‐related adverse events.…”

Section: Discussion Of Case Reportsmentioning

confidence: 99%

The current state of postoperative imaging in the presence of deep brain stimulation electrodes

et al. 2017

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For more than a decade, medically refractory movement disorders have been treated with deep brain stimulation (DBS) devices. Bilateral DBS of the subthalamic nucleus (STN), globus pallidus, and thalamus have been effective in reducing the complications of medications in later-stage movement disorder patients. However, the effectiveness of the DBS device is highly dependent on the proper radiologic and electrophysiological identification of DBS target structures and the accurate placement of the DBS electrodes. The reasons for suboptimal results from DBS surgery could be related to several factors such as patient selection (preoperative), precision of DBS electrode placement (intraoperative), and inadequate device programming and follow-up (postoperative). 1 It should be mentioned from the outset that, regardless of the target, the issues of postoperative MRI in the presence of electrodes hold true.Limited clinical improvement from DBS therapy may result from misplaced electrodes during the intraoperative procedure. Magnetic resonance imaging (MRI) of DBS electrodes is the preferred method for confirming the anatomical location of electrodes given the amount of detail obtained. Recently, computerized topography (CT) has been used for electrode localization by fusing the postoperative CT with the preoperative MRI. This method could introduce more error given the fusion process required (eg, brain shift, CT air pockets). There is an implicit need for the localization of DBS electrodes with a postoperative MRI, and no amount of experienced DBS programming can compensate for a poorly placed electrode. 1 Furthermore, a CT scan cannot replace invaluable MRI scan sequences that are used for diagnostic purposes (outside electrode localization).However, the current restrictions on the postoperative MRI of electrodes has resulted in many centers opting out of the procedure. Importantly, although the potential danger imposed by MRI scanning in the presence of electrodes should not be disregarded, the fear of such procedures should not impact patient care. The current viewpoint will assume that MRI scanning is being performed with both the leads and implantable pulse generator in place. Regardless of the patient, treating neurologist, or the implantation technique, postoperative MRI scanning is invaluable for proper electrode placement verification and diagnostic applications. Specific Absorption RateIn 1979, the concept of specific absorption rate (SAR) was introduced by the National Council on Radiation Protection and Measurements for measuring the rate of radiofrequency (RF) energy absorbed by the body. SAR is defined as the mass normalized rate at which RF power is coupled to biological tissue. 2 SAR is measured in units of watts per kilogram (W/kg). 2 The objective of calculating SAR is to limit the rise in body temperature as a result of RF deposition during the MRI procedure. During the MRI procedure, the patient's body temperature is not easy to detect, so SAR is used to control the potential temperature increases. 2 ...

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MRI to differentiate benign from malignant soft-tissue tumours of the extremities: a simplified systematic imaging approach using depth, size and heterogeneity of signal intensity

Abstract: A simplified systematic imaging approach, in the order signal intensity, size and depth, would be a reference to distinguish between benign and malignant soft-tissue tumours for non-experts.

Cited by 73 publications

References 16 publications

Shear-Wave Elastography of Benign versus Malignant Musculoskeletal Soft-Tissue Masses: Comparison with Conventional US and MRI

Shear-Wave Elastography of Benign versus Malignant Musculoskeletal Soft-Tissue Masses: Comparison with Conventional US and MRI

Low SAR ³¹P (multi‐echo) spectroscopic imaging using an integrated whole‐body transmit coil at 7T

The current state of postoperative imaging in the presence of deep brain stimulation electrodes

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MRI to differentiate benign from malignant soft-tissue tumours of the extremities: a simplified systematic imaging approach using depth, size and heterogeneity of signal intensity

Abstract: A simplified systematic imaging approach, in the order signal intensity, size and depth, would be a reference to distinguish between benign and malignant soft-tissue tumours for non-experts.

Cited by 73 publications

References 16 publications

Shear-Wave Elastography of Benign versus Malignant Musculoskeletal Soft-Tissue Masses: Comparison with Conventional US and MRI

Shear-Wave Elastography of Benign versus Malignant Musculoskeletal Soft-Tissue Masses: Comparison with Conventional US and MRI

Low SAR 31P (multi‐echo) spectroscopic imaging using an integrated whole‐body transmit coil at 7T

The current state of postoperative imaging in the presence of deep brain stimulation electrodes

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Product

Resources

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Low SAR ³¹P (multi‐echo) spectroscopic imaging using an integrated whole‐body transmit coil at 7T