Introduction: Contrast-enhanced ultrasound (CEUS) is a dynamic and continuous imaging modality that offers a real-time, direct view of vascularization, flow distribution patterns of different types of lesions. Thanks to second-generation ultrasound-contrast agents, CEUS has become a well-established, live-imaging technique for many organs, but it has never been extensively used for brain imaging, mainly because of bone shielding to ultrasounds. To date, the reported use of intraoperative-CEUS imaging in neurosurgical procedures is very limited. Aim of the study is to provide the first dynamic and continuous intraoperative-CEUS evaluation of different brain lesions. Aim of the study is to provide the first dynamic and continuous intraoperative-CEUS evaluation of different brain lesions.
Methods: All patients included in the study underwent surgery for intracranial tumor with ultrasound guidance. CEUS imaging was obtained before resection of the lesion after microbubble contrast-agent intra-venous injection, using low-acoustic-power contrast-specific modes.
A semi-quantitative offline inter-observer analisys had been performed in order to evaluate lesion visualization with CEUS and perfusion characteristics: afferent/efferent blood vessels, timing for wash-in and wash-out. All data were compared both to pre-op MRI and histopathology.
Results: Between December 2010 and December 2012, 58 patients underwent intraoperative-CEUS imaging while being operated on for different brain lesions. In all cases it was possible to visualize the lesion with CEUS. Main findings were: glioblastomas and metastasis: rapid arterious phase (5') with rapid wash out. Low grade glioma: slow arterious phase (10') with persistent parechymal phase, late wash-out. Meningiomas: rapid arterious phase (5-10') with persistent enhancement. All results are summarized in figure 1 and table 1. No adverse effects were observed.
Conclusions: Our study is the first extensive implementation of intraoperative-CEUS in neurosurgery, providing a dynamic and continuous real-time imaging of different brain lesions, through a direct visualization of the lesion, vascularisation pattern, flow distribution of different types of brain lesions.
Patient Care: Intraoperative-CEUS appears to be a fast, safe, dynamic, real-time, economic tool, which will possibly provide further insight in the pathology of brain lesions.
Learning Objectives: By the conclusion of this session, participants should be able to: 1) understand CEUS imaging 2) evaluate its different features in brain tumor visualization 3) discuss CEUS role in tumor resection
References: 1 - Quaia E. The real capabilities of contrast-enhanced ultrasound in the characterization of solid focal liver lesions. Eur Radiol. 2011 Mar;21(3):457-62. Epub 2010 Nov 24.
2 - Romanini L, Passamonti M, Aiani L, Martegani A, et al.. Economic assessment of contrast-enhanced ultrasonography for evaluation of focal liver lesions: a multicentre Italian experience. Eur Radiol. 2007 Dec;17 Suppl 6:F99-106.
3 - Quaia E. Assessment of tissue perfusion by contrast-enhanced ultrasound. Eur Radiol. 2011 Mar;21(3):604-15. Epub 2010 Oct 7.
4 - Claudon M, Cosgrove D, Albrecht T, Bolondi L, Bosio M, Calliada F, Correas JM, Darge K, Dietrich C, D'Onofrio M, Evans DH, Filice C, Greiner L, Jäger K, Jong N, Leen E, Lencioni R, Lindsell D, Martegani A, Meairs S, Nolsøe C, Piscaglia F, Ricci P, Seidel G, Skjoldbye B, Solbiati L, Thorelius L, Tranquart F, Weskott HP, Whittingham T. Guidelines and good clinical practice recommendations for contrast enhanced ultrasound (CEUS) - update 2008. Ultraschall Med. 2008 Feb;29(1):28-44. No abstract available.
5 - He W, Xiao-qian J, Shuo W et al. Intraoperative contrast-enhanced ultrasound for brain tumors. Clinical Imaging 32 (2008) 419–424.
6 - Harrer JU, Valaikiene J, Koch H, Knorr R, Horn M, Ickenstein G, Bogdahn U, Schlachetzki F. Transcranial perfusion sonography using a low mechanical index and pulse inversion harmonic imaging: reliability, inter-intraobserver variability. Ultraschall Med. 2011 Jan;32 Suppl 1:S95-101. doi: 10.1055/s-0029-1245369. Epub 2010 Apr 22.