MR NEUROIMAGING: CURRENT AND NEWER TECHNIQUES I

CONTENTS

Preface xiMauricio Castillo

Imaging of Brain Tumors with Diffusion-Weighted and Diffusion TensorMR Imaging 379Daniel P. Barboriak

Diffusion-weighted and diffusion tensor MR imaging are beginning to bring new in-sights into the microscopic structure of brain tumors and adjacent white matter. This ar-ticle reviews the potential use of diffusion-weighted imaging and diffusion tensor MRimaging for evaluation of patients with brain tumors at each phase of their evaluation.The availability of these techniques promises to change the way radiologists evaluatebrain tumors by improving the characterization of intracranial masses, aiding treatmentplanning, and improving the assessment of treatment effectiveness. In addition, thesetechniques may yield information that decreases the risks associated with tumor resec-tion, and allow earlier detection of treatment failures.

Perfusion MR Imaging: Basic Principles and Clinical Applications 403Soonmee Cha

Dynamic contrast-enhanced susceptibility-weighted perfusion MR imaging of the brainprovides hemodynamic information that complements the anatomic information attain-able with conventional MR imaging. Contrast-enhanced perfusion MR imaging methodsexploit signal changes that accompany the passage of a paramagnetic contrast agentthrough the cerebrovascular system and can be used to derive information on blood vol-ume and flow. In this article, the basic principles and methodology underlying dynamiccontrast-enhanced susceptibility-weighted perfusion MR imaging are described. In addi-tion, the clinical applications of perfusion MR imaging-derived maps of cerebral bloodvolume in the diagnosis of brain tumors and other intracranial mass lesions and the pit-falls and limitations of the technique are discussed.

MR Spectroscopy of Brain Tumors 415J. Keith Smith, Mauricio Castillo, and Lester Kwock

MR spectroscopy is a non-invasive technique for measuring tissue metabolites. Changesin tissue metabolites may be useful for diagnosing or characterizing primary and otherbrain neoplasms, planning treatment, and assessing the results of treatment. Ongoing

VOLUME 11 Æ NUMBER 3 Æ AUGUST 2003 v

improvements in equipment and pulse sequence design may make full brain spectros-copy clinically practical in the near future. The authors review the basic concepts ofMR spectroscopy and its use in clinical management of brain neoplasms.

Intraoperative MR Imaging 431Sabine Fenchel, Daniel T. Boll, and Jonathan S. Lewin

Intraoperative MR imaging has revolutionized the way neurosurgery is performed. Ben-efits include the ability to update data sets for navigational systems, to monitor tumorresections, to adjust the approach to intracranial lesions, and to guide functional anddrug or cell delivery procedures. Use of this technique can help avoid inadvertent injuryof important anatomic and vascular structures. In addition, complications such as ische-mia or hemorrhage can be detected early. Intraoperative MR imaging is particularly use-ful for ensuring that brain biopsies yield diagnostic tissue and for assessing thecompleteness of tumor resection. As is true for any new technology, the benefits of in-traoperative MR imaging must be examined carefully to guarantee appropriate use.

Newer MR Imaging Techniques for Head and Neck 449Gaurang V. Shah, Nancy J. Fischbein, Rahul Patel, and Suresh K. Mukherji

Dynamic and functional imaging techniques are being developed to improve the evalua-tion of various pathologic processes of the head and neck region. These techniques in-clude dynamic contrast-enhanced MR imaging for evaluating soft tissue masses andcervical lymph nodes, the use of ultrasmall superparamagnetic iron oxide contrast agent,and functional techniques such as in vivo and in vitro MR spectroscopy of head and neckcancer and lymph nodes and apparent diffusion coefficient mapping of parotid glands.These techniques can help to differentiate nonmalignant tissue from malignant tumorsand lymph nodes and can aid in differentiating residual malignancies from postradiationchanges. From methodological development, they are making the critical transition topreclinical and clinical validating methods and eventually to widespread clinical tools.

Magnetization Transfer, HASTE, and FLAIR Imaging 471Zoran Rumboldt and Miljenko Marotti

This article reviews magnetization transfer (MT), half-Fourier acquisition single-shotturbo spin-echo (HASTE), and fluid-attenuated inversion recovery (FLAIR) MR tech-niques and their applications in neuroradiology. The clinical utility of MT in MR angi-ography has been firmly established, and MT also is used for spine and postcontrastimaging. Quantitative MT studies are valuable for the investigation of different disor-ders, primarily those affecting white matter. Advantages of HASTE are the reductionof motion and magnetic susceptibility artifacts, and this modality has become thesequence of choice for fetal MR imaging. FLAIR has been employed widely and success-fully for the evaluation of central nervous system lesions and is considered an integralpart of standard brain MR studies.

Application of New MR Techniques in Pediatric Patients 493P. Ellen Grant and Kant M. Matsuda

Pediatric neuroradiology is a fascinating and challenging field because there are changesassociated with normal development and unique and unusual pathologies that occur inthis population. The numerous new MR techniques first applied in the adult populationare appropriate for use in the pediatric population, often with minimal modification ofparameters. These new techniques will undoubtedly contribute significantly to the roleof pediatric neuroimaging in diagnosing disease, but the adult experience is not alwaysdirectly transferable. The pediatric brain, particularly the immature brain, is different in

vi CONTENTS

structure, has predilection for different types of disease processes, and may react differ-ently to insults than the adult brain. As a result, the role of these techniques needs to beevaluated in the context of the pediatric brain and common pediatric disease processes.

Index 523

CONTENTS vii