Christoph U. Herborn

Magnetic resonance imaging of experimental atherosclerotic plaque: Comparison of two ultrasmall superparamagnetic particles of iron oxide

To evaluate a new ultrasmall superparamagnetic particles of iron oxide (USPIO) compound, ferumoxytol, as a marker of macrophage activity in atherosclerotic plaques and to compare it to ferumoxtran‐10.

Total-body 3D magnetic resonance angiography influences the management of patients with peripheral arterial occlusive disease

High-resolution total-body 3D MR angiography (MRA) has recently become available, revealing additional clinically relevant disease in patients with peripheral arterial occlusive disease (PAOD). However, the actual impact of total-body MRA on patient management in patients with PAOD has not been investigated so far. Two hundred forty-nine consecutive patients with angiographically proven PAOD were prospectively examined by means of contrast-enhanced total-body 3D MRA on a 1.5-T MR scanner. All correlative imaging studies performed within 60 days of total-body MRA were included in the efficacy analysis. Additional clinically relevant disease (luminal narrowing >50%, aneurysmal changes or dissections) was found in 73 segments (52 patients), including the renal arteries (36 segments), carotid arteries (28 segments), subclavian arteries (four segments) and abdominal aortic aneurysms (AAA) (five segments). Of the 73 segments, 36 were deemed necessary for further investigation by means of focused MRA examinations; the diagnosis was confirmed in all cases. Within the 60-day follow-up period, interventional or surgical therapy outside the peripheral arterial tree was performed in nine patients (11 segments), including carotid endatherectomy and renal artery angioplasty. The outlined total-body 3D MRA approach permits a comprehensive evaluation of the arterial system in patients with atherosclerosis and does indeed have an impact on patient management in patients with PAOD.

The efficacy of gadobenate dimeglumine (Gd-BOPTA) at 3 Tesla in brain magnetic resonance imaging: comparison to 1.5 Tesla and a standard gadolinium chelate using a rat brain tumor model.

Objectives:The objectives of this study were to analyze the differences in contrast enhancement using gadobenate dimeglumine (Gd-BOPTA or MultiHance) at 3 T versus 1.5 T and to compare Gd-BOPTA with a standard gadolinium chelate, gadopentetate dimeglumine (Gd-DTPA or Magnevist), at 3 T in a rat glioma model. Materials and Methods:Twelve rats with surgically implanted gliomas were randomized to either comparing Gd-BOPTA at 1.5 T versus 3 T (n = 7) or comparing Gd-BOPTA and Gd-DTPA at 3 T (n = 5). Matched T1-weighted spin-echo techniques were used for both comparisons and the order of examinations was randomized. Signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and lesion enhancement (LE) were evaluated using a region-of-interest analysis. A veterinary histopathologist evaluated all brain specimens. Results:In the evaluation of Gd-BOPTA at 3 T and 1.5 T, there were significant increases in SNR, LE, and CNR at 3 T. Average increases in brain and tumor SNR were 93% (P < 0.0001) and 92% (P < 0.0001), respectively. CNR increased by 121% (P < 0.0001). Comparison of Gd-BOPTA and Gd-DTPA at 3 T demonstrated significantly higher CNR and LE with Gd-BOPTA. CNR increased by 35% (P = 0.002). LE increased by 44% (P = 0.03). Conclusions:Gd-BOPTA provides significantly higher CNR at 3 T compared with 1.5 T and also demonstrates significantly higher CNR when compared with a standard Gd-chelate at 3 T. As a result of transient protein binding, Gd-BOPTA may be superior to standard gadolinium chelates in neurologic imaging at 3 T.

Nephrogenic systemic fibrosis is not exclusively associated with gadodiamide

The subject of nephrogenic systemic fibrosis (NSF), first addressed in the radiological community in this journal a few months ago [1], is a fast-moving topic with new details arising almost every day. NSF is a rare, debilitating, and sometimes fatal condition that only occurs in patients with severe renal impairment. It is characterized by the formation of connective tissue in the skin, which becomes thickened,

Diagnostic Performance of Gadobenate Dimeglumine–Enhanced MR Angiography of the Iliofemoral and Calf Arteries: A Large-Scale Multicenter Trial

OBJECTIVE The purpose of this study was to compare gadobenate dimeglumine-enhanced MR angiography and unenhanced time-of-flight MR angiography for the detection of significant peripheral arterial occlusive disease using digital subtraction angiography as our reference standard. SUBJECTS AND METHODS Two hundred seventy-two patients underwent MR angiography and digital subtraction angiography of the iliofemoral arteries. MR angiography was performed before (2D time-of-flight acquisitions) and after (spoiled gradient-echo acquisitions) the administration of 0.1 mmol/kg of gadobenate dimeglumine at 1-2 mL/s. Contrast-enhanced MR angiography and digital subtraction angiography of the calf arteries were performed in 241 of 272 participants. Images were evaluated on-site and by four blinded reviewers (three for MR angiography, one for digital subtraction angiography). Comparative diagnostic performance for the detection of significant (> or = 51% vessel lumen narrowing) disease was evaluated using the McNemar test and generalized estimating equations. Interobserver agreement was assessed with generalized kappa statistics. The chi-square test was used to compare technical failure rates. RESULTS Digital subtraction angiography confirmed significant disease (597 stenoses, 386 occlusions) in 983 iliofemoral segments. The sensitivity (54-80.9%), specificity (89.7-95.3%), and accuracy (85-87.5%) of contrast-enhanced MR angiography for the detection of significant iliofemoral disease were significantly (p < 0.001, all reviewers) better than those of time-of-flight MR angiography (33.2-62.8%, 74.3-88.9%, and 68-77.3%, respectively). Similar diagnostic performance was obtained for the calf arteries. The technical failure rate with contrast-enhanced MR angiography (2.5-3.4%) was similar to that of digital subtraction angiography (1.4%) and significantly (p < 0.001) lower than that of time-of-flight MR angiography (6.2-18.0%). Significantly better reproducibility (p < 0.001) was obtained with contrast-enhanced MR angiography (82% vs 65.2% agreement; kappa = 0.66 vs 0.45). CONCLUSION Improved diagnostic performance and reproducibility are achievable with gadobenate dimeglumine-enhanced MR angiography in patients with peripheral arterial occlusive disease.

Comparison of the high relaxivity Gd chelates P1152 and Gd-BOPTA for contrast-enhanced MR angiography in rabbits at 1.5 Tesla and 3.0 Tesla.

To compare signal‐enhancing properties of the high relaxivity Gd chelates P1152 and Gd‐BOPTA for contrast‐enhanced MR angiography (CE‐MRA) in rabbits at 1.5 Tesla (T) and 3.0T.

Contrast Agents for MR Angiography

Recent years have seen the rapid development of techniques and applications for contrast-enhanced magnetic resonance angiography (CE-MRA) and the growing acceptance of the method in clinical routine. In addition to advances in hardware and software design, especially the development in the field of contrast media for CE-MRA has triggered the modality to increasingly become the diagnostic standard of reference for vascular imaging. Despite the majority of MR contrast agents is still lacking the direct approval for CE-MRA, this chapter reviews the properties and characteristics of both currently available agents and those which have been developed recently and are now on their way to the clinical market.

Vasovist ® in Lymphography

The lymphatic system is of paramount importance for the drainage of the interstitial fluid. Lymph nodes account for the enrichment of lymph fluid and play a central role in many diseases, especially in cancer. Due to its anatomical complexity, the lymphatic system has always been difficult to assess with imaging techniques. The combination of new contrast agents and advanced magnetic resonance imaging (MRI) techniques now permits semi-invasive assessment of both the lymphatic vessels and lymph nodes. Due to its transient and strong albumin binding, Vasovist® (Gadofosveset, Bayer Schering Pharma AG, Berlin, Germany) seems an ideal candidate for lymph node imaging.