[Show abstract][Hide abstract] ABSTRACT: To assess whether ECG-gated non-contrast 2D steady-state free precession (SSFP) imaging allows for exact monitoring of aortic diameters in Marfan syndrome (MFS) patients using non-ECG-gated contrast-enhanced 3D magnetic resonance angiography (CE-MRA) and echocardiography for intraindividual comparison.
[Show abstract][Hide abstract] ABSTRACT: Objectives
To evaluate in-stent lumen visibility of 27 modern and commonly used coronary stents (16 individual stent types, two stents at six different sizes each) utilising a third-generation dual-source CT system.
Stents were implanted in a plastic tube filled with contrast. Examinations were performed parallel to the system's z-axis for all stents (i.e. 0°) and in an orientation of 90° for stents with a diameter of 3.0 mm. Two stents were evaluated in different diameters (2.25 to 4.0 mm). Examinations were acquired with a collimation of 96 × 0.6 mm, tube voltage of 120 kVp with 340 mAs tube current. Evaluation was performed using a medium-soft (Bv40), a medium-sharp (Bv49) and a sharp (Bv59) convolution kernel optimised for vascular imaging.
Mean visible stent lumen of stents with 3.0 mm diameter ranged from 53.3 % (IQR 48.9−56.7 %) to 73.9 % (66.7−76.7 %), depending on the kernel used at 0°, and was highest at an orientation of 90° with 80.0 % (75.6−82.8 %) using the Bv59 kernel, strength 4. Visible stent lumen declined with decreasing stent size.
Use of third-generation dual-source CT enables stent lumen visibility of up to 80 % in metal stents and 100 % in bioresorbable stents.
[Show abstract][Hide abstract] ABSTRACT: To include the flip angle distribution caused by the slice profile into the model used for describing the relaxation curves observed in inversion recovery Look-Locker FLASH T1 mapping for a more accurate determination of the relaxation parameters.
[Show abstract][Hide abstract] ABSTRACT: PURPOSE
In Fabry disease progressive deposition of sphingolipids in different organs has been reported. High-field 1H-MR-spectroscopy (MRS) allows non-invasive determination of myocardial lipid content. This study investigates the role of myocardial steatosis in the complex pathomechanism of Fabry cardiomyopathy.
METHOD AND MATERIALS
In 14 patients (9 female, 5 male; 39 ± 13 years [range 17-52 years]) with genetically proven Fabry disease, myocardial triglycerides were quantified by 1H MRS (respiratory motion compensated, ECG triggered) in vivo using a 3 T scanner (Magnetom TRIO, Siemens Sector HealthCare, Germany). Single-voxel-spectroscopy was performed with and without water suppression. The voxel was positioned in the interventricular septum using a four-chamber and short-axis orientation at end systole to avoid signal contamination by epicardial fat. Two triglyceride peaks were measured (methylene groups at 1.3 ppm, methyl groups at 0.9 ppm) relative to the resonance from tissue water at 4.7 ppm. The myocardial lipid content was expressed as triglycerides-to-water ratio (%). In addition left ventricular (LV) mass and ejection fraction (EF) were assessed by MRI. Nine healthy volunteers (4 female, 5 male) without a history of cardiac or metabolic disease served as control group.
In all patients 1H spectra were successfully acquired. In patients the mean triglyceride-to-water ratio was 1.7% (min. 0.1%; max. 6.2%). On average the control group showed a lower (p=0.05) triglyceride-to-water ratio of 0.49% (min. 0.1%; max. 1.9%). Compared to healthy controls, LV mass (mean ± standard deviation; 120 ± 36 g) tended to be higher in Fabry patients (FP) (142 ± 43.9 g) (p=0.1). Mean EF was similar in both groups (67 % in FP vs. 66 % in controls).
High-field 1H-MR-spectroscopy using 3T scanners allows non-invasive assessment of myocardial lipid content in FP. In a relatively small patient collective we observed an elevated myocardial triglyceride content. This finding warrants further studies with larger patient groups, especially concerning sub-group analysis of LE positive and negative FPs.
Besides data regarding functional and morphological alterations MRS delivers new insights into myocardial lipid metabolism in FP. This might help to further optimize the therapy for this rare disease.
Radiological Society of North America 2013 Scientific Assembly and Annual Meeting; 12/2013
[Show abstract][Hide abstract] ABSTRACT: PURPOSE/AIM
To demonstrate the whole procedure of normal and pathologic defecation in conventional (CD) and MR defecography (MRD) as well as imaging findings after surgical treatment (e.g. STARR/POP STARR).
1. To review the indications 2. To show the techniques including dynamic 3D MR defecography 3. To demonstrate important measures as anorectal angle (ARA) and perineal descent (PD); to get familiar with pathologic findings such as intussuception, enterocele, rectocele, sigmoidocele, cystocele, Retzius and Douglas hernia; to discriminate functional disorders (e.g. spastic pelvis floor syndrome) 4. To learn about surgical treatment options like i.e. stapled transanal resection (STARR) for intussusception and POP STARR for pelvic organ prolaps and their appearance in CD and MRD 5. Limitations of both modalities.
The radiologist - especially when working in the coloproctologic field - should be familiar with the techniques, indications and limitations of CD and MRD. As there are successful surgical procedures in patients with obstructive defecation syndrome he should have experience in interpreting post-operative defecography.
Radiological Society of North America 2013 Scientific Assembly and Annual Meeting; 12/2013
[Show abstract][Hide abstract] ABSTRACT: Purpose: Marfan syndrome (MFS) is a genetic disorder of the connective tissue. Aortic root dilation is a main criterion of the Ghent Nosology. Dural ectasia and the presence of mitral valve prolapse (MVP) contribute to its systemic score. The purpose of this study was to investigate the frequency of dural ectasia and its correlation with cardiovascular manifestations in a pediatric study population.Patients and methods: 119 pediatric patients with confirmed or suspected MFS were examined in the local Marfan Clinic. 31 children with MFS who underwent magnetic resonance imaging (MRI) were included. Each patient was evaluated according to the Ghent nosology. Echocardiography was used to measure the aortic root diameter and assess the presence of MVP and mitral regurgitation. Z-scores were calculated for the evaluation of the aortic root diameters. MRI was performed to determine the dural sac ratio (DSR).Results: The prevalence of dural ectasia was 90.3 %, of aortic root dilation 32.2 %, of MVP 64.5 % and of mitral regurgitation 51.6 %. DSR at L5 correlated with the intraindividual z-scores (slope, 3.62 ± 1.5 [0.56; 6.68]; r = 0.17; p = 0.02; F = 5.84). Z-scores ≥ 2 were accompanied by dural ectasia in 100 %, MVP in 95 % and mitral regurgitation in 100 % of cases. MVP was accompanied by mitral regurgitation in 70 % of cases.Conclusion: As the examined cardiac manifestations show a coincidence with dural ectasia in 95 - 100 % of cases, MRI for diagnostic dural sac imaging should be reserved for MFS suspicions with the absence of those manifestations in order to establish the diagnosis according to the Ghent criteria. Thus, the present study supports the recent downgrading of dural ectasia to a contributor to the systemic score.Citation Format:
RöFo - Fortschritte auf dem Gebiet der R 09/2013; · 2.76 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: There is growing concern over the long-term radiation exposure from serial computed tomographic (CT) scan follow-up after endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms (AAAs). Screening for endoleaks with non-contrast-enhanced volumetric CT has been shown to significantly reduce radiation doses. We evaluated the use of NCT as the primary method of follow-up after EVAR of AAAs. METHODS: Our institutional post-EVAR CT protocol consisted of contrast-enhanced CT angiography (CTA) 1 month after repair, followed by NCT at 3 or 6 and 12 months, and annually thereafter. At each follow-up scan, immediate 3-dimensional volume analysis was performed. If the volume change was <2%, NCT follow-up was continued. If the volume increased by ≥2% on nonenhanced images, contrast-enhanced CT was performed immediately to identify potential endoleaks. All images were reviewed by an experienced cardiovascular radiologist. End points included identification of endoleak, reintervention, and rupture. RESULTS: Over a 7-year period, 126 patients were followed. Serial CTA was performed in 59 patients, while 67 patients were followed with the NCT protocol. The mean follow-up was 2.07 years. There were no differences in age, sex, or initial aneurysm volume or size. There were 35 total endoleaks identified. Twenty of these were early endoleaks (<30 days post-EVAR). The remaining 15 leaks were late in nature (10 in the contrast group and 5 in the noncontrast group; P = 0.17). NCT aneurysm sac volume changes prompted contrasted studies in all 5 late leaks. The mean volume change was 11.2 cm(3), an average change of 5.88%. These findings were not significantly different than the late leaks found by routine contrast studies (8.9 cm(3); 4.98% [P = 0.58]). There were no delayed ruptures or emergent reinterventions in the NCT group. CONCLUSIONS: Serial NCT appears to be safe and effective as the sole means of follow-up after EVAR for AAAs. AAA volume increases of ≥2% should prompt further contrast-enhanced CT imaging. Changes of <2% can be safely followed with serial NCT. This protocol requires dedicated cardiovascular radiologist involvement, and patients should be retained in the radiology suite until real-time image evaluation can be completed.
Annals of Vascular Surgery 05/2013; · 0.99 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: OBJECTIVE: To evaluate the association between aortic arch calcifications (AAC) on chest radiography and coronary artery calcium (CAC) score determined by CT. METHODS: A total of 128 patients (75 men; 69.3 ± 14.7 years) who underwent chest radiography and CAC scoring at CT were included in this retrospective analysis. The extent of AAC on chest radiography was evaluated independently by two blinded observers using a semi-quantitative four-point scale (0-3). Intra- and interobserver agreement was assessed by weighted ĸ statistics. Amount of AAC determined on radiography was correlated with CAC and ROC analyses performed to characterise the diagnostic performance of AAC grading. RESULTS: Excellent intraobserver (ĸ = 0.82) and good interobserver (ĸ = 0.75) agreement of AAC grading was noted. Moderate agreement (ĸ = 0.46, 95 % CI 0.36-0.56) with a linear trend (P < 0.0001) between AAC grades and CAC scores was found. Cut-off between AAC grades 0-2 and 3 had a sensitivity of 38.6 %, specificity of 96.4 %, PPV of 85.0 %, NPV of 75.0 % and accuracy of 76.6 % for the correct identification of CAC scores greater than 400. CONCLUSION: Semi-quantitative AAC grading on chest radiography is reliable and positively associated with CAC scoring. We propose to report the extent of AAC in comprehensive radiological reports as "not present", "moderate" or "severe", as severe AAC strongly suggests coronary artery calcification. KEY POINTS: • Semi-quantitative aortic arch calcification (AAC) grading on plain chest radiography appears reliable. • AAC grading is positively associated with CT coronary artery calcium scoring. • AAC grading has a high specificity for ruling out CAC scores greater than 400. • We propose the reporting of the extent of AAC grade in chest X-ray (CXR) reports.
[Show abstract][Hide abstract] ABSTRACT: Giant cell arteritis (GCA) is the most common systemic vasculitis in persons aged 50 and above (incidence, 3.5 per 100 000 per year). It affects cranial arteries, the aorta, and arteries elsewhere in the body, e.g., in the limbs.
We selectively review the pertinent literature, including guidelines and recommendations from Germany and abroad.
The typical symptoms of new-onset GCA are bitemporal headaches, jaw claudiacation, scalp tenderness, visual disturbances, systemic symptoms such as fever and weight loss, and polymyalgia. The diagnostic assessment comprises laboratory testing (erythrocyte sedimentation rate, C-reactive protein), imaging studies (duplex sonography, high-resolution magnetic resonance imaging, positron-emission tomography), and temporal artery biopsy. The standard treatment is with corticosteroids (adverse effects: diabetes mellitus, osteoporosis, cataract, arterial hypertension). A meta-analysis of three randomized controlled trials led to a recommendation for treatment with methotrexate to lower the recurrence rate and spare steroids. Patients for whom methotrexate is contraindicated or who cannot tolerate the drug can be treated with azathioprine instead.
Giant cell arteritis, if untreated, progresses to involve the aorta and its collateral branches, leading to various complications. Late diagnosis and treatment can have serious consequences, including irreversible loss of visual function.
Deutsches Ärzteblatt International 05/2013; 110(21):376-86. · 3.54 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Many scientific manuscripts submitted for publication are flawed by conceptual mistakes. This leads to the rejection of potentially valuable scientific data in renowned journals. This article intends to guide young researchers with respect to writing a well-structured scientific radiological manuscript.
RöFo - Fortschritte auf dem Gebiet der R 03/2013; · 2.76 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Purpose: In 2011 a nationwide outbreak of Shiga toxin-producing E. coli (STEC) O104:H4 infection occurred in Germany with severe hemorrhagic colitis and hemolytic-uremic syndrome (HUS). We defined abdominal radiologic findings in these patients and correlated them with clinical parameters. Materials and Methods: 23 patients (7 men; age: 48 ± 19 years) with O104:H4 colitis and/or HUS received abdominal CT (n = 12) or radiographs (n = 11). Colonic distension, air-fluid levels, and free intraabdominal air were assessed. Colonic wall thickening, contrast enhancement, pericolic stranding, and ascites were evaluated on CT. Laboratory parameters and clinical presentation were reviewed. Chi-square test, Student's t-test, McNemar's test and Spearman correlation were performed. Results: Colonic lumen distension was seen in 16/23 patients (69.6 %). The ascending colon (11/23 patients; 47.8 %) and transverse colon (12/23 patients; 52.2 %) were dilated significantly more often (p = 0.006 and p = 0.003, respectively) than the descending colon (1/23; 4.3 %). All 12 patients undergoing CT scanning had abnormally thickened colonic wall segments, 3 (25 %) had pancolic involvement and 9 (75 %) had segmental involvement. The descending colon was predominantly affected (11/12 patients; 91.7 %) and thickened significantly more often than other colonic segments (p < 0.001). Conclusion: The segmental type of STEC O104:H4 colitis mainly affects the descending colon with upstream distension of the transverse/ascending colon and differs from other types of colitis.
RöFo - Fortschritte auf dem Gebiet der R 02/2013; · 2.76 Impact Factor