Quantitative correlational study of microbubble‐enhanced ultrasound imaging and magnetic resonance imaging of glioma and early response to radiotherapy in a rat model

Abstract

Purpose: Radiotherapy remains a major treatment method for malignant tumors. Magnetic resonance imaging (MRI) is the standard modality for assessing glioma treatment response in the clinic. Compared to MRI, ultrasound imaging is low-cost and portable and can be used during intraoperative procedures. The purpose of this study was to quantitatively compare contrast-enhanced ultrasound (CEUS) imaging and MRI of irradiated gliomas in rats and to determine which quantitative ultrasound imaging parameters can be used for the assessment of early response to radiation in glioma. Methods: Thirteen nude rats with U87 glioma were used. A small thinned skull window preparation was performed to facilitate ultrasound imaging and mimic intraoperative procedures. Both CEUS and MRI with structural, functional, and molecular imaging parameters were performed at preradiation and at 1 day and 4 days postradiation. Statistical analysis was performed to determine the correlations between MRI and CEUS parameters and the changes between pre-and postradiation imaging. Results: Area under the curve (AUC) in CEUS showed significant difference between preradiation and 4 days postradiation, along with four MRI parameters, T 2 , apparent diffusion coefficient, cerebral blood flow, and amide proton transfer-weighted (APTw) (all p < 0.05). The APTw signal was correlated with three CEUS parameters, rise time (r = −0.527, p < 0.05), time to peak (r = −0.501, p < 0.05), and perfusion index (r = 458, p < 0.05). Cerebral blood flow was correlated with rise time (r = −0.589, p < 0.01) and time to peak (r = −0.543, p < 0.05). Conclusions: MRI can be used for the assessment of radiotherapy treatment response and CEUS with AUC as a new technique and can also be one of the assessment methods for early response to radiation in glioma. C 2015 American Association of Physicists in Medicine.

Assessment of the use of contrast enhanced ultrasound in guiding microdissection testicular sperm extraction in nonobstructive azoospermia

“…PI indicated the maximum number of microbubbles in the capillaries, so it represented the number of capillaries. PIT indicated the number of capillaries in the entire testicle, and AUCT indicated the microbubble distribution in the entire testicle [ 16 ].…”

Magnetic resonance imaging-guided radiation therapy using animal models of glioblastoma

“…31 Pre-clinical, these more advanced MR techniques were used by the MR research group at John Hopkins University for the assessment of response to RT in a rat model of GB. [32][33][34] Hong et al 34 performed longitudinal quantitative multiparametric MRI, in addition to standard T 2 weighted MR. The quantitative MR sequences included T 1 relaxometry, T 2 relaxometry, diffusion-weighted imaging (DWI), arterial spin labelling and chemical exchange-dependent saturation transfer (CEST) techniques.…”

“…This research group also compared their multiparametric MR approach to contrast-enhanced ultrasound imaging (CEUS) and observed that several CEUS-based metrics correlated well with MR-based metrics. 33 They summarised that CEUS might be a low-cost and portable alternative to multiparametric MR for the assessment of treatment response.…”

Using ultrasound-targeted microbubble destruction to enhance radiotherapy of glioblastoma

“…Glioma is the most common and fatal type of primary brain tumors (Gusyatiner and Hegi 2018 ). Glioblastoma (GBM) accounts for 60–70% of these malignancies (Yang 2015 ) and has an average survival time of 12–15 months (Alexander and Cloughesy 2017 ). Due to the unique anatomical position and moderate radiosensitivity of tumors, radiotherapy (XRT) has been playing a leading role in the treatment of tumors.…”