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OBJECTIVE Intraoperative contrast-enhanced ultrasound (iCEUS) offers dynamic imaging and provides functional data in real time. However, no standardized protocols or validated quantitative data exist to guide its routine use in neurosurgery. The authors aimed to provide further clinical data on the versatile application of iCEUS through a technical note and illustrative case series. METHODS Five patients undergoing craniotomies for suspected tumors were included. iCEUS was performed using a contrast agent composed of lipid shell microspheres enclosing perflutren (octafluoropropane) gas. Perfusion data were acquired through a time-intensity curve analysis protocol obtained using iCEUS prior to biopsy and/or resection of all lesions. RESULTS Three primary tumors (gemistocytic astrocytoma, glioblastoma multiforme, and meningioma), 1 metastatic lesion (melanoma), and 1 tumefactive demyelinating lesion (multiple sclerosis) were assessed using real-time iCEUS. No intraoperative complications occurred following multiple administrations of contrast agent in all cases. In all neoplastic cases, iCEUS replicated enhancement patterns observed on preoperative Gd-enhanced MRI, facilitated safe tumor debulking by differentiating neoplastic tissue from normal brain parenchyma, and helped identify arterial feeders and draining veins in and around the surgical cavity. Intraoperative CEUS was also useful in guiding a successful intraoperative needle biopsy of a cerebellar tumefactive demyelinating lesion obtained during real-time perfusion analysis. CONCLUSIONS Intraoperative CEUS has potential for safe, real-time, dynamic contrast-based imaging for routine use in neurooncological surgery and image-guided biopsy. Intraoperative CEUS eliminates the effect of anatomical distortions associated with standard neuronavigation and provides quantitative perfusion data in real time, which may hold major implications for intraoperative diagnosis, tissue differentiation, and quantification of extent of resection. Further prospective studies will help standardize the role of iCEUS in neurosurgery.

One of the major pitfalls faced by physicians is a basic lack of understanding of the legal aspects of medical malpractice. It is the authors' hope that the brief review of the history of malpractice law provided here affords the radiologist insights that could prove helpful in understanding how one must conduct oneself in a radiology practice. There are several noteworthy points to consider. Vigilance and minimizing errors is always most desirable, but error-free neuroradiology is unattainable. Best medical judgment, although not error free, is at least defensible as noted in the case law discussed here.

Multiple sclerosis (MS) is a demyelinating disease in the central nervous system. Genetics have been considered as a leading factor in the prevalence and disease course of MS. We have presented an informatics-based eFolder system for integrating patients' clinical data with MR images and lesion quantification results. The completed eFolder system has been designed and developed in aiding to evaluate disease manifestation differences in Hispanic and Caucasian MS patients. MS lesion data, as shown in MRI, can be extracted by the 3-D automatic lesion detection tool in the eFolder, and data storing and mining tools in eFolder is able to extract and compare data from individual patients. The computer-aided detection (CAD) algorithm has been modified and enhanced to include spatial information as detection criteria. For this study, 36 Caucasian MS patients and 36 matched Hispanic patients have been selected. Most recent MR images of the patients are collected, and images are evaluated both by the CAD tool in the eFolder and radiologists. The results are compared between Caucasian and Hispanic patients and statistically evaluated to see if the two populations have significant difference in lesion presentations. The results can be used to evaluate differences in the two groups of patients and to evaluate the new CAD algorithm's performance with radiologists' contours. Significant findings can further evaluate effectiveness of MS eFolder in MS-related research.

Conventional contrast-enhanced MR imaging is the current standard technique for the diagnosis and treatment evaluation of gliomas and other brain neoplasms. However, this method is quite limited in its ability to characterize the complex biology of gliomas and so there is a need to develop more quantitative imaging methods. Perfusion and permeability MR imaging are two such techniques that have shown promise in this regard. This review will highlight the underlying principles, applications, and pitfalls of these evolving advanced MRI methods.

The use of dynamic contrast agent-enhanced magnetic resonance imaging (MRI) can provide insight into hemodynamic processes not detectable during static conventional contrast-enhanced MR techniques. These additional data may allow further refinement of differential diagnoses focusing on interpretation in terms of microvascular physiology. The dominant dynamic gadolinium (Gd)-enhanced bolus injection MR techniques currently utilized in brain imaging are (1) T1-weighted dynamic contrast-enhanced (DCE) and (2) T2/T2*-weighted dynamic susceptibility contrast (DSC) imaging. This chapter will provide an overview of general physical principles of these techniques.