This retrospective study examines 248 test bolus examinations preceding contrast-enhanced magnetic resonance angiography (CE-MRA) to extract clinically relevant data for critical limb ischemia (CLI) management. The method involved a retrospective review of test bolus exams, analysing 60 graphs for time to peak (TTP), full-width half-maximum (FWHM) time, and time to continual rise in signal intensity. These values were correlated with heart function parameters (ejection fraction, ASA classification, Lee index, and MET score). The results indicate a mean TTP of 31.2 ± 7.3 s, showing a correlation between the ejection fraction and ASA classification. Patients with atrial fibrillation exhibited prolonged TTP compared to those without. Despite population heterogeneity, these findings facilitate risk stratification for limb-saving interventions in CLI. TTP emerges as a potential clinical cardiovascular parameter and a risk factor for vascular interventions. Given the variation in injection protocols across centres, this study underscores the importance of precise bolus arrival time documentation for future multicentre studies.

Abstract Background Cardiac synovial sarcoma of the heart is a rare, aggressive mesenchymal tumor with poor prognosis, since complete resection is seldom feasible. Case presentation A 23-year-old man was referred in cardiogenic shock. Emergency computed tomography (CT) revealed a large tumor with obstruction of the right atrium (RA) and prolapse into the right ventricle (RV). Resection and pericardial patch plasty were performed. Histology confirmed a G-3 spindle-cell sarcoma. At 21 months postoperatively, CT and cardiac magnetic resonance (MR) angiography showed a tumor emerging from the lateral wall of the superior caval vein (SCV) and the RA. The RA and SCV were completely resected and replaced with a tailored Dacron tunnel prosthesis. Histology confirmed R0 resection of a G-3 spindle-cell sarcoma. Reverse transcription-polymerase chain reaction (RT-PCR) confirmed a monophasic fibrous synovial sarcoma. Echocardiography upon discharge showed normal biventricular function. The heart was tumor-free upon PET-CT 24 months thereafter. A sudden progression with innumerable pulmonary nodules caused only minimal exertional dyspnea, and the patient received palliative monochemotherapy with ifosfamide. Thirty months after the first operation, he succumbed to hemorrhage from a brain metastasis. Conclusions We report an unusually long postoperative period of 30 months in our patient after resection of a very large right atrial sarcoma. Early diagnosis, aggressive surgical treatment, adjunctive chemotherapy and radiotherapy affect survival. Systematic inclusion of patients in multicenter initiatives, including biobanking, is necessary. Better knowledge of genetic defects relevant to these cardiac tumors will promote accurate diagnoses and suggest novel and personalized gene-based therapies.

BACKGROUND:The aim of this single-center combined prospective/retrospective cohort study was to analyze Gadolinium (Gd)-enhanced MRA (magnetic resonance angiography) and MRV (MR venography) for the diagnosis of pulmonary artery embolism and deep venous thrombosis. The gold standard methods result in major exposure to radiation and a high amount of nephrotoxic iodinated contrast media. This is the first larger contrast-enhanced MR imaging study of acute and chronic venous thromboembolic disease of various stages.METHODS:We prospectively examined 88 patients presenting clinical signs of deep vein thrombosis and/or pulmonary artery embolism. A single-session, one-stop shop Gd-enhanced MRA/MRV at 1.5 Tesla, using gradient echo sequences with very short repetition and echo times as well as low flip angles with subtraction and three-dimensional reconstruction, was performed. A diagnosis was made with the consensus of two experienced radiologists.RESULTS:We observed excellent MRA image quality in 87% and even higher diagnostic image quality of MRV in 90% of our examinations. Pulmonary artery embolism occurred with deep vein thrombosis in 22%.CONCLUSIONS:Gd-enhanced MRA/MRV provided excellent image quality for the diagnosis of venous thromboembolic disease in the majority of cases. It may be particularly useful to plan and follow-up filter implantation and retrieval in the inferior caval vein.

Zusammenfassung Einleitung Das Poplitealarterien-Entrapment-Syndrom (PAES) beschreibt einen pathologischen Zustand, bei dem sich durch anatomische Anomalien der Lagebeziehung zwischen zumeist muskulären Weichteilstrukturen des Caput mediale des M. gastrocnemius (CMMG) und der A. poplitea (AP) eine mechanische Kompression und eine daraus folgende Schädigung der Gefäße bis zum Verschluss ergibt. Patienten In den Jahren 2012 bis 2018 wurden 3 männliche Patienten im Alter zwischen 17 und 48 Jahren wegen eines PAES an unserer Abteilung operiert. Der 1. Patient wurde bereits 2003 mit 23 Jahren einer femoropoplitealen Bypassoperation bei der Diagnose „PAVK II b posttraumatisch“ unterzogen. Nach mehrmaliger Revision fiel 2012 schließlich intraoperativ ein starker, nach lateral ziehender, die Gefäße einengender Sehnenzügel des CMMG auf. Nach Durchtrennung des Sehnenzügels wurde die aneurysmatische Bypassvene ersetzt. Der 2. Patient wurde 2014 mit der Diagnose „PAVK II b bei thrombosiertem Poplitealaneurysma“ nach intraarterieller Lyse mit wandhaftenden Restthromben vorstellig. Intraoperativ zeigte sich proximal des Aneurysmas ein zum CMMG ziehender Sehnenzug, welcher die AP einengte. Beim 3. Patienten trat 2018 eine Fußsohlen- und Wadenclaudicatio rechts mit abgeblasstem und pulslosem Unterschenkel auf. Bildgebend zeigte sich ein Verschluss der Poplitealarterien beidseits. Nach intraarterieller Lyse zeigte die HRMR-Untersuchung des Knies einen atypischen Verlauf der AP von medial das CMMG ventral kreuzend. Die operative Sanierung wurde durch Myotomie und Refixation des Muskels in physiologischer Position vorgenommen. Alle Patienten erhielten eine individuelle medikamentöse Re-Thromboseprophylaxe. Von der Operation der Gegenseite bei simultan bestehendem PAES wurde bei mangelndem Therapiewunsch der Patienten abgesehen. Schlussfolgerung Das PAES ist selten und wird i. d. R. mit jungen, sportlich aktiven, meist männlichen Patienten mit ausgeprägter Unterschenkelmuskulatur in Verbindung gebracht. Eine späte Diagnose des PAES kann, wie der 1. Fall zeigt, zu schweren Gefäßschäden, unnötigen Rezidiveingriffen und über Jahre protrahiertem Krankheitsverlauf führen. Bei jungen Patienten mit Wadenclaudicatio sollte daher stets auch unabhängig von der körperlichen Konstitution die Differenzialdiagnose PAES erwogen werden.

OBJECTIVE:The aim of this study was to assess the potential risk of gadobutrol-enhanced magnetic resonance imaging (MRI) in patients with moderate to severe renal impairment for the development of nephrogenic systemic fibrosis (NSF).MATERIALS AND METHODS:We performed a prospective, international, multicenter, open-label study in 55 centers. Patients with moderate to severe renal impairment scheduled for any gadobutrol-enhanced MRI were included. All patients received a single intravenous bolus injection of gadobutrol at a dose of 0.1 mmol/kg body weight. The primary target variable was the number of patients who develop NSF within a 2-year follow-up period.RESULTS:A total of 908 patients were enrolled, including 586 with moderate and 284 with severe renal impairment who are at highest risk for developing NSF. The mean time since renal disease diagnosis was 1.83 and 5.49 years in the moderate and severe renal impairment cohort, respectively. Overall, 184 patients (20.3%) underwent further contrast-enhanced MRI with other gadolinium-based contrast agents within the 2-year follow-up. No patient developed symptoms conclusive of NSF.CONCLUSIONS:No safety concerns with gadobutrol in patients with moderate to severe renal impairment were identified. There were no NSF cases.

IntroductionWe describe a patient with an undifferentiated endometrial cancer who initially declined treatment, thus permitting study of the early hypothetical in vivo growth kinetics of the tumor and the natural history of the disease.

OBJECTIVE:This prospective multicenter intraindividual crossover study was designed to compare gadobenate dimeglumine and gadofosveset trisodium at approved doses with respect to the image quality and diagnostic performance of contrast-enhanced MR angiography (CE-MRA) in the detection of clinically relevant renal artery stenosis.SUBJECTS AND METHODS:Thirty-nine subjects (17 men, 22 women; age range, 30-86 years; mean 62 +/- 13.3 [SD] years) with known or suspected renovascular disease underwent a first CE-MRA examination with 0.1 mmol/kg gadobenate dimeglumine and a second examination 3-12 days later with 0.03 mmol/kg gadofosveset. Identical T1-weighted spoiled gradient-refocused echo coronal first-pass images were acquired for 38 of the 39 patients. For 15 of the 38 patients, additional sagittal or axial images or both were acquired with gadofosveset during the steady-state phase. Thirty-four patients underwent digital subtraction angiography, which was the reference standard. Three independent blinded readers assessed source images and maximum-intensity-projection reconstructions to detect clinically relevant (> 50%) renal artery stenosis. Diagnostic performance (sensitivity, specificity, accuracy, positive and negative predictive values) was evaluated with the McNemar and Wald tests. Matched-pair determinations of diagnostic preference were evaluated with Wilcoxon's signed rank test. Reader agreement was determined with kappa analysis, and safety was assessed.RESULTS:Comparison of first-pass images revealed superior sensitivity (75.7-86.5% vs 68.4-76.3%), specificity (92.1-98.6% vs 90.5-93.9%), accuracy (88.9-96.2% vs 85.9-90.3%), positive predictive value (70.0-94.1% vs 65.0-76.3%), and negative predictive value (94.0-96.6% vs 91.7-93.9%) with gadobenate dimeglumine. Significant superiority was noted for specificity (p < or = 0.02), accuracy (p < or = 0.005), and positive predictive value (p < or = 0.018). Steady-state images showed no benefit of gadofosveset. Reader agreement was good to excellent (gadobenate dimeglumine, kappa = 0.855; gadofosveset, kappa = 0.776). Reader preference was for gadobenate dimeglumine in 11, 17, and 13 patients and for gadofosveset in five, four, and five patients. No safety concerns were noted.CONCLUSION:Better diagnostic performance and reader preference were found for gadobenate dimeglumine than gadofosveset in first-pass renal CE-MRA.

G. Reishofer, R. Merwa, M. Aschauer, S. Zitta, R. Stollberger, and F. Ebner Department of Radiology / MR-Physics, Medical University of Graz, Graz, Austria, Institute of Medical Engineering, Graz University of Technology, Graz, Austria, Department of Radiology, Medical University of Graz, Graz, Austria, Department of Internal Medicine / Division of Nephrology, Medical University of Graz, Graz, Austria, Department of Radiology / Division of Neuroradiology, Medical University of Graz, Graz, Austria

Introduction: Variable density 3D random sampling trajectories which were introduced in the context of compressed sensing [1] have great potential for subsampled CE-MR angiography techniques which deliver data sets with high contrast to noise ratio. The goal of this work was to present a parameter-free method to construct variable density sampling patterns which are tailored to angiography. Sampling patterns are generated with the use of a probability density function (pdf) that is constructed by using measured k-space data as a reference, which automatically ensures an appropriate distribution of sample points. It is also shown that these data sets can be used together with a nonlinear parallel imaging method [2, 3]. This combination allows the use of very high acceleration factors while still yielding images with excellent image quality.

Purpose: To determine the most efficacious dose of gadodiamide for three-dimensional (3D) contrast-enhanced (CE) magnetic resonance angiography (MRA) of the renal arteries on a patient level based on the sensitivity in detecting the main hemodynamically relevant (>= 50% or occlusion) renal artery stenosis (RAS) using intra-arterial digital subtraction angiography (IA DSA) as the gold standard.Materials and Methods: This prospective, randomized, double-blind, parallel-group, multicenter study included 273 patients referred to IA DSA for suspected RAS. Patients underwent 3D CE MRA after injection of 0.01, 0.05, 0.1, or 0.2 mmol/kg of body weight gadodiamide (0.5 mmol/ml). The images were assessed for location and degree of RAS by independent blinded readers (MRA: three readers, IA DSA: one reader). Hypothesis testing for a significant trend in sensitivity across dose groups was based on the one-sided Cochran-Armitage style trend test for each independent MRA reader.Results: The lowest dose group (0.01 mmol/kg) proved non-efficacious in detecting hemodynamically relevant (i.e., >= 50% or occlusion) RAS. A statistically significant dose trend (p < 0.001) was shown for each of the three independent readers. Depending on reader, the sensitivity obtained with 0.05,0.1. and 0.2 mmol/kg was 63.9-86.1%, 75.8-91.4% and 80.6-90.6%, the specificity was 66.7-73.9%, 59.3-75.0%, and 59.3-75.0% and accuracy was 67.8-78.9%, 75.4-77.4%, and 76.3-81.0%, for the three dose groups, respectively. There were eight non-severe adverse events (AEs). Three serious AEs occurring in one patient were judged not related to gadodiamide by the on-site investigator.Conclusion: A significant dose trend between the four doses examined was observed. The lowest dose (0.01 mmol/kg) differed significantly from those of the other three doses. Based on the analysis of the primary and secondary endpoints, 0.1 mmol/kg gadodiamide appears to be the most suitable dose in diagnosing hemodynamically relevant RAS. The present study also demonstrated gadodiamide to be safe and well tolerated. (c) 2007 Elsevier Ireland Ltd. All rights reserved.

Pulmonary embolism and deep venous thrombosis are individual manifestations of a single entity, venous thromboembolic disease. This study aimed to assess the feasibility of 3-dimensional gadolinium-enhanced magnetic resonance angiography used as an "one-stop shop'' imaging procedure visualizing both the pulmonary arteries and the deep lower venous system within a single investigation. The inclusion criterion was a proven or excluded venous thromboembolism. Diagnosis was based on an imaging work-up for pulmonary embolism including either perfusion lung scan or contrast-enhanced spiral computed tomography, or both, and an imaging work-up for deep venous thrombosis including either venous color-coded duplex sonography or ascending phlebography, or both. A gadolinium-enhanced "one-stop shop'' magnetic resonance angiography was performed within 24 hours of completed diagnostic imaging work-up for pulmonary embolism and deep venous thrombosis in 20 patients. Results of pulmonary magnetic resonance angiography were concordant with perfusion lung scan and/or computed tomography in 90% of patients. Magnetic resonance angiography results of the deep lower venous system were concordant with venous duplex sonography and/or phlebography in 75% of patients and seemed to be more precise in 25% of patients. The "one-stop shop'' imaging procedure using gadolinium-enhanced magnetic resonance angiography was feasible and proved to offer a reliable and rapid diagnostic approach in thromboembolic disease, sparing patients' exposure to ionizing radiation and iodinated contrast media.

With magnetic resonance angiography and computed tomography, congenital anomalies of the inferior vena cava are diagnosed more frequently than they used to be. Accessory renal arteries identified by magnetic resonance angiography in a patient with an anomalous inferior vena cava indicated a combination of arterial and venous abnormalities. The study was initiated to screen consecutive patients with an anomalous inferior vena cava for concomitant abdominal and pelvic arterial abnormalities, and their first-degree relatives for congenital vascular anomalies. Magnetic resonance angiography identified in 2 of 5 patients with an anomalous inferior vena cava concomitant accessory renal arteries and in 5 of 11 first-degree relatives major abdominal vascular anomalies including accessory renal arteries, accessory renal veins, and anomalies of the hepatic artery. None of the relatives showed abnormalities of the inferior vena cava. The familial occurrence of vascular anomalies strongly suggests an underlying pathogenetic component in affected family members. In patients with a congenital anomaly of the inferior vena cava, concomitant arterial abnormalities should be considered. First-degree relatives may be at risk for congenital vascular anomalies.

The purpose of this study was to assess interobserver variability and accuracy in the evaluation of renal artery stenosis (RAS) with gadolinium-enhanced MR angiography (MRA) and digital subtraction angiography (DSA) in patients with hypertension. The authors found that source images are more accurate than maximum intensity projection (MIP) for depicting renal artery stenosis. Two independent radiologists reviewed MRA and DSA from 38 patients with hypertension. Studies were postprocessed to display images in MIP and source images. DSA was the standard for comparison in each patient. For each main renal artery, percentage stenosis was estimated for any stenosis detected by the two radiologists. To calculate sensitivity, specificity and accuracy, MRA studies and stenoses were categorized as normal, mild (1–39%), moderate (40–69%) or severe (≥70%), or occluded. DSA stenosis estimates of 70% or greater were considered hemodynamically significant. Analysis of variance demonstrated that MIP estimates of stenosis were greater than source image estimates for both readers. Differences in estimates for MIP versus DSA reached significance in one reader. The interobserver variance for MIP, source images and DSA was excellent (0.80< κ≤ 0.90). The specificity of source images was high (97%) but less for MIP (87%); average accuracy was 92% for MIP and 98% for source images. In this study, source images are significantly more accurate than MIP images in one reader with a similar trend was observed in the second reader. The interobserver variability was excellent. When renal artery stenosis is a consideration, high accuracy can only be obtained when source images are examined.

Ziele: Bestimmung der Wertigkeit des blood-pool Kontrastmittels NC100150 (Amersham Health, Oslo, Norwegen) zur Evaluation von Thrombosen der tiefen Becken- und Beinvenen. Methode: Es wurden 12 Patienten prospektiv mittels konventioneller Venographie (XRV) und mittels MR Venographie (MRV) nach Injektion von NC100150 (2ml/kg KG) untersucht. Die source images und 3D maximum intensity projection images (MIP) wurden an einer unabhängigen Workstation ausgewertet. Die Diagnose wurde von 2 Radiologen im Konsens erhoben. Ergebnis: Bei 87 Venen waren sowohl die XRV als auch die MRV von diagnostischer Qualität. In der XRV wurden in 30 von 87 Venen Thromben gefunden (34,5%). Übereinstimmung in der Thrombusdiagnose lag bei 83 von 87 Venen vor (95,4%; Kappa=0,9). Im Vergleich zur XRV hatte die blood-pool MRV insgesamt eine Sensitivität und Spezifität von 93,3% und 96,5%. Zwei Thrombosen der vena poplitea und der vena tibialis posterior kamen in der MRV zur Darstellung, nicht aber in der XRV. Andererseits konnten zwei Venenthrombosen unterhalb des Kniegelenkes nicht mittels MRV dargestellt werden, wohl aber in der XRV. Schlussfolgerung: NC100150 erlaubt eine verlängerte und verbesserte Darstellung der peripheren Venen und könnte einige Einschränkungen der gadoliniumverstärkten MRV umgehen. Es ist eine vollständigere Untersuchung der proximalen Venen möglich als in der konventionellen XRV. Arterielle und venöse Kontrastierung und Bewegungsartefakte können jedoch zu Einschränkungen der Bildinterpretation führen.