Use of intraoperative ultrasound for localizing tumors and determining the extent of resection: a comparative study with magnetic resonance imaging

Abstract

A prospective study of 70 patients with intraparenchymal brain lesions (36 gliomas and 34 metastases) was performed to evaluate the efficacy of intraoperative ultrasound (IOUS) in localizing and defining the borders of tumors and in assessing the extent of their resection. Eighteen of the 36 glioma patients had no previous therapy. All of these 18 tumors were well localized by IOUS; margins were well defined in 15 and moderately defined in three. The extent of resection was well defined on IOUS in all 18 patients, as confirmed by measurements taken on postoperative magnetic resonance (MR) images (p = 0.90). The remaining 18 patients with gliomas had undergone previous surgery and/or radiation therapy; five had recurrent tumors and 13 had radiation-induced changes. The extent of resection of the recurrent tumors was well defined in all but one patient, as confirmed by postoperative MR imaging. The extent of resection was poorly defined in all 13 patients whose pathology showed radiation effects. All 34 metastatic lesions were well localized and had well-defined margins. In addition, IOUS accurately determined the extent of resection in all cases, the results were confirmed with postoperative MR imaging. In conclusion, IOUS is not only helpful in localizing and defining the margins of gliomas and metastatic brain lesions, it also accurately determines the extent of resection, as confirmed by postoperative MR imaging. This assessment does not apply, however when the lesion is due primarily to radiation effect.

3T Intraoperative MRI for Management of Pediatric CNS Neoplasms

“…[19][20][21][22][23] Few uses of sonography have been shown in pediatric tumors. 24,25 Sonography is highly operatordependent, and proper orientation with respect to the resection cavity can be difficult.…”

Mutual‐information‐based image to patient re‐registration using intraoperative ultrasound in image‐guided neurosurgery

“…Studies have shown that tumor segmentation in iUS is more reliable for metastases and some high-grade gliomas, but is poor for low-grade gliomas. 36,37 To this end, we included only segmentation of well-defined boundaries to add confidence in the analysis and minimize bias from segmentation uncertainty. Further, in the low-grade glioma case ͑patient 2͒, we used the high contrast cyst boundary for the analysis.…”

Fusion imaging for intra-operative ultrasound-based navigation in neurosurgery

“…Another technique extensively used during neurosurgical procedures is intra-operative Ultrasounds (iUS); in recent years, multiple studies demonstrated their value in tumor detection during surgery, giving to iUS a foreground position in the field of intraoperative imaging [6][7][8][9]. The main point of value of iUS consists in obtaining a real-time scan repeatable as many times as necessary without the cost and the duration of other intraoperative techniques.…”