Angiogenesis is essential for the development of malignant tumors and provides important targets for tumor diagnosis and therapy. To noninvasively assess the angiogenic profile of tumors, novel α_vβ₃ integrin–targeted ultrasmall superparamagnetic iron oxide particles (USPIOs) were designed and their specific uptake by endothelial cells was evaluated in vitro and in vivo. USPIOs were coated with 3-aminopropyltrimethoxysilane (APTMS) and conjugated with Arg-Gly-Asp (RGD) peptides. Accumulation in human umbilical vein endothelial cells (HUVECs) was evaluated using Prussian blue staining, transmission electron microscopy, magnetic resonance (MR) imaging, and inductively coupled plasma mass spectrometry. Uptake of RGD-USPIO by HUVECs was significantly increased when compared with unlabeled USPIO and could be competitively inhibited by addition of unbound RGD. The ability of the RGD-USPIO to noninvasively distinguish tumors with high (HaCaT-ras-A-5RT3) and lower (A431) area fractions of α_vβ₃ integrin–positive vessels was evaluated using a 1.5-T MR scanner. Indeed, after RGD-USPIO injection, there was a more pronounced decrease in T₂ relaxation times in HaCaT-ras-A-5RT3 tumors than in A431 tumors. Furthermore, T₂*-weighted images clearly identified the heterogeneous arrangement of vessels with α_vβ₃ integrins in HaCaT-ras-A-5RT3 tumors by an irregular signal intensity decrease. In contrast, in A431 tumors with predominantly small and uniformly distributed vessels, the signal intensity decreased more homogeneously. In summary, RGD-coupled, APTMS-coated USPIOs efficiently label α_vβ₃ integrins expressed on endothelial cells. Furthermore, these molecular MR imaging probes are capable of distinguishing tumors differing in the degree of α_vβ₃ integrin expression and in their angiogenesis profile even when using a clinical 1.5-T MR scanner. [Cancer Res 2007;67(4):1555–62]

Proton magnetic resonance imaging (MRI) has recently emerged as a clinical tool to image the lungs. This paper outlines the current technical aspects of MRI pulse sequences, radiofrequency (RF) coils and MRI system requirements needed for imaging the pulmonary parenchyma and vasculature. Lung MRI techniques are presented as a “technical toolkit”, from which MR protocols will be composed in the subsequent papers for comprehensive imaging of lung disease and function (parts 2 and 3). This paper is pitched at MR scientists, technicians and radiologists who are interested in understanding and establishing lung MRI methods. Images from a 1.5 T scanner are used for illustration of the sequences and methods that are highlighted.Main Messages• Outline of the hardware and pulse sequence requirements for proton lung MRI• Overview of pulse sequences for lung parenchyma, vascular and functional imaging with protons• Demonstration of the pulse-sequence building blocks for clinical lung MRI protocols

This report describes the development of a robotic assistance system that provides precise and reproducible instrument positioning inside the MRI or CT gantry on the basis of processed imagery. Percutaneous interventions such as MRI-guided insertion of cannulae and probes for biopsy, drainage, drug delivery, and energetic tumor destruction were primary drivers in the robotic design. Applications involving the central nervous system have been excluded because of the demanding medical device regulations and approval process. The developed system received the Conformite Europeenne (CE) mark in 2005 and is marketed under the brand name INNOMOTION. It is currently in clinical use for MRl-guided sciatic pain and facet joint treatments, biopsies,drainages, and CT-guided osteosynthesis. This article reviews the development and evaluation of the system.

²³Na MRI has the potential to noninvasively detect sodium (Na) content changes in vivo. The goal of this study was to implement ²³Na MRI in a clinical setting for neurooncological and muscular imaging. Due to the biexponential T₂ decay of the tissue Na signal with a short component, which ranges between 0.5–8 ms, the measurement of total Na content requires imaging techniques with echo times (TEs) below 0.5 ms. A 3D radial pulse sequence with a TE of 0.2 ms at a spatial resolution of 4 × 4 × 4 mm³ was developed that allows the acquisition and presentation of Na images on the scanner. This sequence was evaluated in patients with low‐ and high‐grade gliomas, and higher ²³Na MR signals corresponding to an increased Na content were found in the tumor regions. The contrast‐to‐noise ratio (CNR) between tumor and white matter increased from 0.8 ± 0.2 to 1.3 ± 0.3 with tumor grade. In patients with an identified muscular ²³Na channelopathy (Paramyotonia congenita (PC)), induced muscle weakness led to a signal increase of ∼18% in the ²³Na MR images, which was attributed to intracellular Na⁺ accumulation in this region. Magn Reson Med 57:74–81, 2007.

Purpose: The exact detection and delineation of the intraprostatic tumour burden is crucial for treatment planning in primary prostate cancer (PCa). We compared ⁶⁸Ga-HBED-CC-PSMA PET/CT with multiparametric MRI (mpMRI) for diagnosis and tumour delineation in patients with primary PCa based on slice by slice correlation with histopathological reference material.