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

• Published in: Medical physics (Lancaster) 2015-08, Vol.42 (8), p.4762-4772
• Main Authors: Yang, Chen, Lee, Dong‐Hoon, Mangraviti, Antonella, Su, Lin, Zhang, Kai, Zhang, Yin, Zhang, Bin, Li, Wenxiao, Tyler, Betty, Wong, John, Wang, Ken Kang‐Hsin, Velarde, Esteban, Zhou, Jinyuan, Ding, Kai
• Format: Article
• Language: English
• Subjects: 60 APPLIED LIFE SCIENCES; Animals; Area Under Curve; biodiffusion; Biological material, e.g. blood, urine; Haemocytometers; biomedical MRI; BIOMEDICAL RADIOGRAPHY; biomedical ultrasonics; BLOOD; BLOOD FLOW; brain; Brain - pathology; Brain - physiopathology; Brain Neoplasms - diagnostic imaging; Brain Neoplasms - pathology; Brain Neoplasms - physiopathology; Brain Neoplasms - radiotherapy; Cancer; Cell Line, Tumor; Cerebrovascular Circulation - physiology; Cerebrovascular Circulation - radiation effects; CEUS; Contrast Media; CORRELATIONS; Diagnosis using ultrasonic, sonic or infrasonic waves; DIAGRAMS; Doppler effect; Echoencephalography - methods; Flow visualization; Fluid mechanics and rheology; Fluid transport and rheology; Functional imaging; glioma; Glioma - diagnostic imaging; Glioma - pathology; Glioma - physiopathology; Glioma - radiotherapy; GLIOMAS; Haemodynamics; haemorheology; Humans; Involving electronic [emr] or nuclear [nmr] magnetic resonance, e.g. magnetic resonance imaging; IRRADIATION; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Male; Microbubbles; Molecular Imaging - methods; MRI; Neoplasm Transplantation; NMR IMAGING; PULSE RISE TIME; RADIATION PROTECTION AND DOSIMETRY; radiation therapy; Radiation treatment; RADIOTHERAPY; RATS; Rats, Nude; SKULL; statistical analysis; Time Factors; Tissue Measurements; Treatment Outcome; tumours; Ultrasonographic imaging; Ultrasonography; ultrasound
• ISSN: 0094-2405; 2473-4209
• DOI: 10.1118/1.4926550

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, T2, 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.