Kontrastmittelanwendung auf Hochfeld-(3 T-)MRT

The basic diagnostic efficacy of MR contrast medium in the evaluation of primary brain tumors and its clinical usefulness in the detection of brain metastases with single and cumulative triple-dose was compared using a high-field 3T MR unit and a 1.5 T MR unit. Additionally, the effect of contrast agent on high-resolution MR venography based on the BOLD effect was evaluated at both field strengths. Tumor-brain contrast after gadodiamide administration, as assessed by means of statistical evaluation of MP-RAGE scans and T1-SE images, was significantly higher at 3 T than at 1.5 T. The subjective assessment of cumulative triple-dose 3 T images obtained the best results in the detection of brain metastases, followed by 1.5 T cumulative triple-dose enhanced images. Due to higher spatial resolution, contrast-enhanced MR venography at 3 T showed more details in and around tumors than at 1.5 T, additionally enhanced by stronger susceptibility weighting and higher signal-to-noise ratio at 3 T. In summary, administration of gadolinium-based contrast agent produces higher contrast between tumor and normal brain at 3 T than at 1.5 T, helps to detect more cerebral metastases at 3 T than at 1.5 T in single and cumulative triple dose, and improves MR venography at 3 T with increase in spatial resolution within the same measurement time, thus providing more detailed information

Role of Standard Magnetic Resonance Imaging

Bone disease is a clinical hallmark of multiple myeloma (MM), occurring in almost all patients during the course of the disease. It represents one of the main causes of morbidity and mortality in affected patients and can justify on its own the initiation of treatment in presence of a biopsy-proven medullary or extramedullary plasmacytoma. Over the past few years, modern imaging techniques have gained increasing importance in the management of MM. Currently, cross-sectional imaging is incorporated in the definition of myeloma-related bone disease deserving of treatment and is required for a correct staging as well as for treatment-response evaluation. Magnetic resonance imaging (MRI) allows to directly visualize bone marrow infiltration much earlier than myeloma-related bone destruction and it is considered the imaging gold-standard method for the detection of myeloma bone marrow involvement. MRI is the procedure of choice to evaluate painful lesions and discriminating between benign from malignant vertebral fractures and it has also the ability to localize spinal cord and/or nerve root compression for surgical intervention or radiation therapy. Moreover, whole-body MRI is currently included in the diagnostic work-up of otherwise considered asymptomatic myeloma and solitary bone plasmacytoma, with remarkable therapeutic implications. However, despite its added value in the initial disease assessment, conventional MRI is of limited value in the evaluation of response after treatment since it only provides morphological information. This chapter will give a comprehensive overview of the role of conventional MRI in diagnostic and post-treatment evaluation of patients with myeloma, underlining its strengths and weaknesses at various time points of the disease. Exhaustive acquisition protocols for an adequate evaluation of bone marrow disease involvement will be discussed in the light of currently accepted standards and the most important MR imaging findings will be illustrated alongside their prognostic value. Understanding the advantages and limitations of conventional MRI and its complementary value in staging and disease monitoring compared to other imaging techniques is essential to optimize patients\u2019 management, especially in the new era of novel treatment approaches that have significantly improved rates and depth of response