MR Angiography

Summary: We present the case of an unusually located in-tracranial lipoma in a 17-year-old patient with partial ep-ilepsy who was being controlled with medication. The li-poma was located deep in the left sylvian fissure, in the inferior parietal lobule, associated with cortical dysplasia of the surrounding supramarginal gyrus. Abnormal vas-culature was detected adjacent to and within the adipose mass. The findings of the imaging studies that included CT, MR imaging, and MR angiography, are described along with a brief review of the literature. Intracranial lipomas are rare lesions, assumed to be resulting from abnormal persistence and maldif-ferentiation of the meninx primitiva, as first pro-posed by Verga (1) and then supported by Truwit and Barkovich (2). The majority of the lesions oc-

Rationale and ObjectivesThe purpose of this study was to compare gadolinium-enhanced magnetic resonance (MR) angiography with contrast material–enhanced computed tomography (CT) for the detection of small (4–5-mm) pulmonary emboli (PE), with a methacrylate cast of the porcine pulmonary vasculature used as the diagnostic standard.

Background and Purpose—We sought to map early regional ischemia and infarction in patients with middle cerebral artery (MCA) stroke and compare them with final infarct size using advanced MRI techniques. MRI can now delineate very early infarction by diffusion-weighted imaging (DWI) and abnormal tissue perfusion by perfusion-weighted imaging (PWI). Methods—Seventeen patients seen within 12 hours of onset of MCA stroke

Severe primary central nervous system (CNS) involvement such as vasculitis and pachymeningitis can rarely occur in rheumatoid arthritis (RA) even in the absence of systemic disease activation. The authors illustrate a female patient with well-controlled RA who presented with headaches, encephalopathy, seizures and relapsing focal neurological deficits. Primary rheumatoid cerebral vasculitis and pachymeningitis were diagnosed based on suggestive brain magnetic resonance (MR) imaging, MR angiography, cerebrospinal fluid analysis and cerebral angiography. MR showed abnormal leptomeningeal enhancement and hyperintense FLAIR signal in the cortical subarachnoid spaces consistent with pachymeningitis. Cerebral angiography findings were consistent with vasculitis. Aggressive treatment resulted in significant clinicoradiological resolution. Cerebral vasculitis is a rare but certain manifestation of RA. This complication can be diagnosed in the presence of suggestive angiographic and CSF find...

The indications for treating carotid artery stenosis are related to the symptomatic nature of the lesion and the degree of stenosis. Duplex sonography is adequate for screening. While some groups believe that Duplex US alone or in combination with transcranial Doppler ...

A B S T R A C T Over the past few decades, vascular flow-dependent imaging techniques have proven to be effective for the visualization of large vessel diseases. However, these approaches are unlikely to be efficacious for small vessels because the affected small vessels cannot always be visualized directly, owing to a lack of detection sensitivity. Recently, many researchers have introduced state-of-the-art imaging techniques to visualize cerebral micro-vessels using ultra-high-field (UHF) magnetic resonance angiography (MRA). They have demonstrated the superiority of UHF MRA, especially for visualization of the microvasculature compared with clinical MRA images using 1.5T or 3T magnetic resonance imaging (MRI). Thus, UHF MRA may become an important investigative tool for research, facilitating examinations of vascular mechanisms for small vessel diseases and contributing to the early detection of cerebrovascular diseases in clinics. Furthermore, new imaging methods for visualizing vascular dynamics or flow effects may help investigate brain functions, especially in conjunction with blood oxygenation level-dependent contrast functional MRI modalities, as well as situations in which small vessel abnormalities are clinically important. The present article reviews recent technological advances in UHF MRA, especially 7T MRA, and discusses the potential benefits and future directions of UHF MRA.

Intracranial stenting is increasingly being used to treat intracranial aneurysms and stenoses. We wanted to assess the utility of magnetic resonance angiography (MRA) in the follow-up of patients treated with various types of intracranial stents and to assess the utility of performing gadolinium-enhanced MRA. A total of 19 patients having undergone intracranial stenting for aneurysms were imaged by MRI at 1.5T. A total of 20 stents were placed in 19 patients. In addition to conventional T2- and diffusion-weighted MRI, 3D time-of-flight MRA was performed before and after contrast administration. In the case of metallic INX stents (N = 7), there was a signal drop at the level of the vessel. which did not allow to evaluating the parent vessel, whereas this was visible in Nitinol stents (N = 8). Additionally a stent with a wire had a small artifact (N = 3). Contrast administration also improved vessel lumen visualization. In the case of Nitinol stents, MRA can be used to reliably demonstrate the vessel lumen after intracranial stenting. The use of postcontrast 3D time-of-flight imaging helps improve the intraluminal definition. J. Magn. Reson. Imaging 2006. © 2006 Wiley-Liss, Inc.

Summary: Subarachnoid hemorrhage from dissecting ver- tebral artery aneurysms is a well-known phenomenon. With the advent of navigable intracranial stents, these aneu- rysms are now amenable to endovascular stent placement. However, immediate aneurysm obliteration is often not accomplished, and current covered stents have poor short- term patency rates. We report a series of three patients with intradural dissecting vertebral artery

Current clinical full MR angiography with multiple breathhold multiple thin slab acquisition (MTS) is difficult and arduous. This study describes the optimisation of the whole heart free - breathing balanced turbo field echo (B-TFE) protocol. A high-resolution image of the whole heart is produced in less or comparable time to MTS acquisition and allows for reconstruction afterwards to visualise the individual coronary arteries. The scan is easily performed because the volume has to be targeted only once. Eighteen healthy adults without a history of cardiovascular disease underwent free-breathing 3D MR angiography with the B-TFE protocol. The whole-heart data set was reformatted in identical orientations in all subjects to visualise the major coronary arteries. Vessel length, signal and contrast to noise ratio were determined and compared for each vessel. Mean visible vessel lengths were 116 mm for the right, 102 mm for the left main and left descending and 76 mm for the left circumflex coronary artery. The average signal to noise ratio was 7.5 and contrast to noise ratio was 4.9. Because of the need for synchronised cardiac and respiratory triggering the coronaries could not be judged in 25% of the subjects. The optimised B-TFE protocol had equal judgeability and vessels could be judged over longer contiguous distances compared to earlier implementations of the B-TFE protocol. We conclude whole heart free breathing navigator-gated and slice-tracked 3D coronary MR angiography with use of the adjusted B-TFE protocol is possible, but still suboptimal for clinical use.

Susceptibility artifact from platinum coil packs impairs the visibility of perianeurysmal soft tissues at conventional 3D time-of-flight MR angiography. These artifacts limit the evaluation for residual-recurrent aneurysm and parent vessel stenosis. Reducing the echo time can decrease the artifact and improve perianeurysmal visualization. The purpose of this study was to assess quantitatively the effect of decreasing the echo time on artifact production at different field strengths and coil pack densities.