Hanno Hoppe

Inselspital, Universitätsspital Bern, Berna, Bern, Switzerland

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Publications (68)156.56 Total impact

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    ABSTRACT: BACKGROUND AND PURPOSE:Conventional platinum coils cause imaging artifacts that reduce imaging quality and therefore impair imaging interpretation on intraprocedural or noninvasive follow-up imaging. The purpose of this study was to evaluate imaging characteristics and artifact production of polymeric coils compared with standard platinum coils in vitro and in vivo.MATERIALS AND METHODS:Polymeric coils and standard platinum coils were evaluated in vitro with the use of 2 identical silicon aneurysm models coiled with a packing attenuation of 20% each. DSA, flat panel CT, CT, and MR imaging were performed. In vivo evaluation of imaging characteristics of polymeric coils was performed in experimentally created rabbit carotid bifurcation aneurysms. DSA, CT/CTA, and MR imaging were performed after endovascular treatment of the aneurysms. Images were evaluated regarding visibility of individual coils, coil mass, artifact production, and visibility of residual flow within the aneurysm.RESULTS:Overall, in vitro and in vivo imaging showed relevantly reduced artifact production of polymeric coils in all imaging modalities compared with standard platinum coils. Image quality of CT and MR imaging was improved with the use of polymeric coils, which permitted enhanced depiction of individual coil loops and residual aneurysm lumen as well as the peri-aneurysmal area. Remarkably, CT images demonstrated considerably improved image quality with only minor artifacts compared with standard coils. On DSA, polymeric coils showed transparency and allowed visualization of superimposed vessel structures.CONCLUSIONS:This initial experimental study showed improved imaging quality with the use of polymeric coils compared with standard platinum coils in all imaging modalities. This might be advantageous for improved intraprocedural imaging for the detection of complications and posttreatment noninvasive follow-up imaging.
    American Journal of Neuroradiology 05/2013; · 3.17 Impact Factor
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    ABSTRACT: The purpose of this study was to simulate pulmonary emboli (PE) and image quality at low tube energy and reduced contrast material volume in normal-dose pulmonary CT angiography (CTA) images and to analyze the diagnostic accuracy with normal- and low-dose pulmonary CTA. Normal-dose pulmonary CTA examinations using 120 kVp and 100 mL of contrast material in 10 patients with no PE were retrospectively selected. The image characteristics of an 80-kVp low-dose pulmonary CTA protocol (patient exposure reduction, 57%) with 75 mL of contrast material were simulated. Four different sets of filling defects were computer simulated in identical locations in each normal-dose and corresponding low-dose examination, equaling 783 PE in 40 normal-dose and 40 low-dose datasets. Ten normal-dose and 10 low-dose examinations contained no emboli and were used as controls. The 100 pulmonary CTA studies were randomly assessed by three readers blinded to PE location and image quality. The results were assessed by nonparametric tests and Student t tests. No difference was found between the CT protocols in terms of sensitivity, specificity, and positive and negative diagnostic likelihood ratios at all ramification levels of the pulmonary arteries (p = 0.343-1). The overall sensitivity and specificity with the normal and simulated low-dose protocols were 79.9% versus 81.3% and 98.0% versus 98.2% (p = 0.444 and 0.702), respectively. The diagnostic confidence (2.81 ± 0.39 vs 2.77 ± 0.47; p = 0.297) and overall image quality (3.92 ± 0.52 vs 3.83 ± 0.54; p = 0.216) were similar at 120 kV and 80 kV. The intraindividual comparison of diagnostic accuracy with normal-dose and simulated low-dose pulmonary CTA protocols revealed no difference under experimental conditions.
    American Journal of Roentgenology 11/2011; 197(5):W852-9. · 2.90 Impact Factor
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    ABSTRACT: Comparison of arterial and venous coronary artery bypass flow measurements using 3-T magnetic resonance (MR) phase contrast in correlation with intraoperative Doppler flow measurements. Fifty-six coronary bypasses (right coronary artery n=18, left internal mammary artery to left anterior descending artery n=16, marginal artery n=7, circumflex artery n=7, diagonal artery n=6, left anterior descending artery n=1, and right internal mammary artery to right coronary artery n=1) were studied in 27 asymptomatic patients. In this prospective study, each bypass was studied intra-operatively using Doppler flow measurement. Within one week post surgery, patients were studied using a 3-T MR scanner (Magnetom Verio, Siemens, Erlangen, Germany) using velocity encoded phase-contrast flow measurements. Intraoperative Doppler flow measurements demonstrated regular flow patterns in all vascular territories supplied. All bypasses were patent on MRI and flow measurement results were as follows: median flow 60ml/min (interquartile range (IQR): 37.5-78.5ml/min). For comparison, the corresponding median intraoperative flow was 58ml/min (IQR: 41-80ml/min) (p<0.001; R=0.44). Linear regression analysis demonstrated a significant correlation for venous bypasses (p=0.0002; R=0.48), but not for arterial bypasses (p=0.09; R=0.24). This study demonstrated that MR flow measurements of venous bypass grafts agreed more with Doppler than arterial bypass grafts. However, bypass patency was confirmed for all patients. In the future, this technique may be used for non invasive coronary bypass graft follow-up.
    European journal of radiology 06/2011; 81(4):e502-6. · 2.65 Impact Factor
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    ABSTRACT: To assess if finite element (FE) models can be used to predict deformation of the femoropopliteal segment during knee flexion. Magnetic resonance angiography (MRA) images were acquired on the lower limbs of 8 healthy volunteers (5 men; mean age 28 ± 4 years). Images were taken in 2 natural positions, with the lower limb fully extended and with the knee bent at ~ 40°. Patient-specific FE models were developed and used to simulate the experimental situation. The displacements of the artery during knee bending as predicted by the numerical model were compared to the corresponding positions measured on the MRA images. The numerical predictions showed a good overall agreement between the calculated displacements of the motion measures from MRA images. The average position error comparing the calculated vs. actual displacements of the femoropopliteal intersection measured on the MRA was 8 ± 4 mm. Two of the 8 subjects showed large prediction errors (average 13 ± 5 mm); these 2 volunteers were the tallest subjects involved in the study and had a low body mass index (20.5 kg/m²). The present computational model is able to capture the gross mechanical environment of the femoropopliteal intersection during knee bending and provide a better understanding of the complex biomechanical behavior. However, results suggest that patient-specific mechanical properties and detailed muscle modeling are required to provide accurate patient-specific numerical predictions of arterial displacement. Further adaptation of this model is expected to provide an improved ability to predict the multiaxial deformation of this arterial segment during leg movements and to optimize future stent designs.
    Journal of Endovascular Therapy 06/2011; 18(3):388-96. · 2.70 Impact Factor
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    ABSTRACT: The purpose of this article is to assess the impact of large patient size on the detection of hypovascular liver tumors with MDCT and the effect of a noise filter on image quality and lesion detection in obese patients. A liver phantom with 45 hypovascular tumors (diameters of 5, 10, and 15 mm) was placed into two water containers mimicking intermediate and large patients. The containers were scanned with a 64-MDCT scanner. The CT dataset from the large phantom was postprocessed using a noise filter. The image noise was measured and the contrast-to-noise ratio (CNR) of the tumors was calculated. Tumor detection was independently performed by three radiologists in a blinded fashion. The application of the noise filter in the large phantom yielded a reduction of image noise by 42% (p < 0.0001). The CNR values of the tumors in the nonfiltered and filtered large phantom were lower than that in the intermediate phantom (p < 0.05). In the non-filtered and filtered large phantom, 25% and 19% fewer tumors, respectively, were detected on average compared with the intermediate phantom (p < 0.01). The risk of missing hypovascular liver tumors with CT is substantially increased in large patients. A noise filter improves image quality in obese patients.
    American Journal of Roentgenology 06/2011; 196(6):W772-6. · 2.90 Impact Factor
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    ABSTRACT: Preoperative mapping of the arterial spinal supply prior to thoracoabdominal aortic aneurysm repair is highly relevant because of high risk for postoperative ischemic spinal cord injuries such as paraparesis or paraplegia. Twenty-four consecutive patients prior to surgical thoracoabdominal aortic aneurysm repair were investigated. All patients underwent steady-state MR angiography (MRA) of the spinal vasculature with 3-T MRI. The sequence used was a steady-state coronary 3D FLASH with 0.7-mm isotropic voxels. MRA was performed using an intravasal contrast agent. Studies were evaluated by three readers including delineation of arterial spinal supply including both aortic origin and spinal canal entry by three readers. Identification and localization of the Adamkiewicz artery and its spinal canal entry was successful in all patients. Overall depiction of the vascular anatomy was graded as very good in 3 (12.5%), good in 14 (58.4%), sufficient in 5 (20.8%), and poor in 2 (8.3%) patients. Depiction of segmental artery aortic exit level was graded as good in 6 (25.0%), sufficient in 10 (41.7%), poor in 4 (16.7%) and not identifiable in 4 (16.7%) patients. Delineation of segmental artery entry level into the spinal canal was graded as very good in 4 (16.7%), good in 11 (45.8%), sufficient in 6 (25.0%), and poor in 3 (12.5%) patients. The use of 3-T MRA with an intravascular contrast agent and steady-state enables AKA localization including its segmental arteries with regard to the level of aortic origin and spinal canal entry in most patients.
    European journal of radiology 03/2011; 81(5):979-84. · 2.65 Impact Factor
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    ABSTRACT: BACKGROUND; Hemoptysis can be an acute medical emergency, which can be localized angiographically and controlled by therapeutic intervention. To evaluate the effectiveness and safety of bronchial artery embolization, and including follow-up in patients with hemoptysis. Thirty-five vascular interventions were performed in 28 patients (nine women and 19 men, mean age 42 years, age range 20-82 years) treated for hemoptysis between January 1998 and October 2008. Underlying diseases were cystic fibrosis (n = 9), lung cancer (n = 6), chronic inflammatory disease (n = 4), bronchiectasis (n = 3), chronic obstructive pulmonary disease (n = 2), and other (n = 4). Bronchial artery embolization was performed using particles. Patients were followed up for a median of 23 months (range 1 month to 8 years). Bronchial artery embolization was technically successful in all patients (bleeding halted within 24 hours). Recurrent bleeding occurred in four patients with cystic fibrosis (14%) at one, 16, 19 and 48 months, respectively. Within this subset, multirecurrence bleeding occurred in one patient with cystic fibrosis. Cumulative patient survival rate was 74% at eight years. No patient died due to hemoptysis but due to underlying disease. Bronchial artery embolization was highly effective in patients with hemoptysis. It may help to avoid surgery in patients who are poor candidates for surgery. Should hemoptysis recur in these patients, repeated embolization can be performed.
    Acta Radiologica 03/2011; 52(2):143-7. · 1.33 Impact Factor
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    ABSTRACT: To evaluate the effectiveness and safety of covered stents for the management of iatrogenic arterial injury. Between 03 / 1998 and 12 / 2009, 31 patients underwent selective covered stent implantation after iatrogenic arterial injury. 12 / 31 of these patients (38.7 %) were hemodynamically unstable. Six different endovascular covered stent types were utilized. The primary endpoints of this study were technical and clinical success and rates of minor and major complications. Initial angiograms demonstrated active extravasation in 19 (61.3 %) patients and pseudoaneurysms in 12 (38.7 %) patients. The following sites of bleeding origin were detected: axillary artery, subclavian artery, common iliac artery, external iliac artery, internal iliac artery, common femoral artery, superficial femoral artery, popliteal and fibular artery, femoro-popliteal and popliteo-crural bypasses, common hepatic artery, aberrant hepatic artery, cystic and gastroduodenal artery. In all patients bleeding was effectively controlled by covered stent implantation resulting in an immediate technical success of 100 %. Clinical success attributed to covered stent implantation was documented in 30 of the 31 patients (96.8 %). Major complications included death in four patients (11.1 %), acute thrombosis with arm ischemia in one patient (2.8 %) and stent fracture with associated pseudoaneurysm in another patient (2.8 %). In 2 / 31 patients (6.5 %) covered stent failure was detected and successfully treated by implantation of a second covered stent. Emergency and elective implantation of covered stents may be used for minimally invasive and effective management of iatrogenic arterial injury.
    RöFo - Fortschritte auf dem Gebiet der R 02/2011; 183(7):618-30. · 2.76 Impact Factor
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    ABSTRACT: The superior vena cava syndrome (SVCS) comprises various symptoms due to occlusion of the SVC, which can be easily obstructed by pathological conditions (eg, lung cancer, due to the low internal venous pressure within rigid structures of the thorax [trachea, right bronchus, aorta]). The resulting increased venous pressure in the upper body may cause edema of the head, neck, and upper extremities, often associated with cyanosis, plethora, and distended subcutaneous vessels. Despite the often striking clinical presentation, SVCS itself is usually not a life-threatening condition. Currently, randomized controlled trials on many clinically important aspects of SVCS are lacking. This review gives an interdisciplinary overview of the pathophysiology, etiology, clinical manifestations, diagnosis, and treatment of malignant SVCS.
    Respiratory care 01/2011; 56(5):653-66. · 2.03 Impact Factor
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    ABSTRACT: Evaluation of a novel non-invasive tool for postoperative follow-up of patients postelective saphenous vein coronary artery bypass graft (CABG) was performed. Ten patients were included. Their bypass grafts supplied the right coronary artery (7), marginal branches (1), diagonal branches (2), and the circumflex artery (n=1). Each bypass was examined intraoperatively using Doppler flow measurement. Patients were examined with a 3-Tesla magnetic resonance imaging (MRI) scanner (MAGNETOM Verio, Siemens, Erlangen, Germany) within one week postsurgery using MR-angiography with an intravasal contrast agent and velocity encoded phase-contrast flow measurements. Intraoperative Doppler flow measurements revealed regular flow patterns in all vascular territories supplied. The median intraoperative flow rate was 50 ml/min with an inter-quartile range (IQR) of 42-70 ml/min. The clinical postoperative course was uneventful. MRI showed all grafts to be patent. The median postoperative flow rate was 50 ml/min (IQR: 32-65 ml/min). MRI flow rates agreed well with intraoperative Doppler flow measurements (mean difference: -2.8±20.1 ml/min). This initial study demonstrates that 3-Tesla MRI flow measurements correlated well with Doppler thus reconfirming the graft patency postCABG. Further refinement and broader application of this technique may facilitate follow-up postCABG potentially replacing empiric clinical judgment by reliable non-invasive imaging.
    Interactive Cardiovascular and Thoracic Surgery 01/2011; 12(4):582-5. · 1.11 Impact Factor
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    ABSTRACT: Endovascular treatment is an increasingly used therapeutic option in patients with chronic atherosclerotic occlusive mesenteric disease. Purpose of this study was evaluation of patency and mortality in patients treated with visceral artery percutaneous transluminal angioplasty (PTA) or stenting including follow-up. A retrospective review of 17 consecutive patients (4 women, 13 men) with endovascular treatment for symptomatic chronic mesenteric ischemia from 1998 to 2004 was performed. Mean follow-up period was 42 months. Patient demographics, interventional details, primary and/or secondary patency and mortality were recorded. Cumulative mortality and patency rates were determined using Kaplan-Meier life table analysis. Twenty-six interventions (PTA alone n=13, PTA and stenting n=13) were performed in 17 patients. Interventions were performed in the superior mesenteric artery (n=13) and celiac artery (n=13). The re-intervention rate was 30% (6/26). Re-interventions were performed for the superior mesenteric artery (n=4) and celiac artery (n=2). Cumulative overall 1-year results were primary patency rate 81%, secondary patency rate 94%, and survival rate 82%. Cumulative 10-year results were primary patency rate 73%, secondary patency rate 94%, and survival rate 65%. The 10-year secondary patency rate was 100% in patients post initial stenting and 86% in patients post initial PTA. Long-term follow-up post endovascular treatment for chronic mesenteric ischemia demonstrated a considerable overall secondary patency rate of 94%. However, the long-term secondary patency rate was higher in patients post initial stenting compared to PTA alone.
    VASA.: Zeitschrift für Gefässkrankheiten. Journal for vascular diseases 11/2010; 39(4):319-24. · 1.01 Impact Factor
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    ABSTRACT: It is unknown whether sorafenib can be combined with transarterial chemoembolization (TACE) in patients with hepatocellular carcinoma. This study assesses the safety and tolerability of a continuous regimen of sorafenib combined with TACE. This was an open-label phase I study testing a continuous administration of sorafenib (dose escalation from 200 mg twice daily [bid] to 400 mg bid) starting 7 days prior to TACE with doxorubicin (50 mg). Twenty-one patients were screened and 14 received sorafenib combined with TACE. Because there were no dose-limiting toxicities in the first three patients who received sorafenib at a dose of 200 mg bid, subsequent patients received 400 mg bid. Twenty-seven procedures were performed (median, two per patient) and two local therapy-related severe adverse events occurred. The median duration of sorafenib therapy was 246 days (range, 14-547 days). Sorafenib-related adverse events of grade ≥3 were hand-foot skin reaction (n = 3), weight loss (n = 2), diarrhea (n = 1), abdominal pain (n = 1), and thrombocytopenia (n = 3). After treatment with sorafenib and TACE, there was a significant decrease in the concentration of plasma vascular endothelial growth factor (VEGF) from 93 ng/l to 67 ng/l. Continuous administration of sorafenib at a dose of 400 mg bid combined with TACE was tolerable. The adverse event profile of this regimen was comparable with that of sorafenib monotherapy with the exception of thrombocytopenia, which may be more frequent. There were no increases in the circulating VEGF levels after TACE with this combined regimen. (Swiss Association for the Study of the Liver study number 25; ClinicalTrials.gov trial identifier, NCT00478374).
    The Oncologist 10/2010; 15(11):1198-204. · 4.10 Impact Factor
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    ABSTRACT: Delayed occlusion time in parent artery occlusion of brain-supplying vessels might carry risk for thromboembolic complications. Vascular plug devices are successfully used in cardiopulmonary and peripheral interventions to occlude high-flow lesions and have been adapted for use in neurointerventions. The purpose of the present study was to experimentally evaluate the immediate occlusion time of the AMPLATZER vascular plug (AVP) II-a second-generation cylindrical, self-expandable, resheathable nitinol wire mesh consisting of three lobes-in the carotid artery. AVP II devices (N = 12) 6 mm in diameter (length, 6 mm) were deployed through 6-F guiding catheters in the common carotid arteries of two pigs. After device deployment, angiography was performed to measure the time interval until no contrast agent opacification was visible distal to the AVP II, indicating complete flow cessation and occlusion of the distal vessel. Vessel diameters before deployment and after resheathing of the device were measured. Device navigation, positioning, recapturing, vasospasm, and angiographic signs of vessel injury were assessed. The mean time to total flow cessation and occlusion was 57.9 seconds (median, 44 s ± 27 [SD]; range, 26-104 s). Device navigation, positioning, and resheathing were successful in all cases. There was neither significant vasospasm nor vessel injury visible on angiography. Application and retrieval of the second-generation AVP II are uncomplicated and the device is able to achieve fast and sufficient cessation of flow in a hemodynamically comparable setting to the human carotid artery, indicating some potential to fill a gap in the neurointerventional tool box.
    Journal of vascular and interventional radiology: JVIR 10/2010; 21(12):1873-7. · 1.81 Impact Factor
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    ABSTRACT: The latest-generation Amplatzer vascular plug (AVP), the AVP 4, is designed for embolization of smaller vessels without a sheath or guiding catheter. This study evaluated the AVP 4 in peripheral vascular embolization. Embolization with the AVP 4 was attempted in 13 patients (11 men) for trauma (n = 7) and other indications (n = 6). Technical success rate, vascular bed, size of catheter, and number and size of AVP 4 devices were recorded. Embolization with the AVP 4 was successful in 10 of 13 patients (77%). In trauma patients (n = 7), embolization of the splenic artery (n = 4), lumbar artery (n = 2), and superior gluteal artery (n = 1) was performed. In other patients, preoperative embolization of the right portal vein (n = 1), a gastric varix after transjugular intrahepatic portosystemic shunt creation (n = 1), an aneurysm of the internal iliac artery (n = 1), and inferior mesenteric artery (IMA) embolization before aneurysm repair (n = 2) was performed. Sizes of the AVP 4 were 4 mm (n = 6), 6 mm (n = 5), and 8 mm (n = 1). In all patients, 4- and 5-F catheters with a 0.038-inch minimum inner lumen were used. In one patient, IMA embolization was attempted via a femoral approach but was unsuccessful as a result of repeated catheter tip dislocation because of acute angle; coils were used instead. Peripheral embolization with the AVP 4 was successful in the majority of patients. Future comparative study is necessary to evaluate this device's benefits over other embolization materials such as earlier-generation AVPs or microcoils.
    Journal of vascular and interventional radiology: JVIR 08/2010; 21(8):1185-90. · 1.81 Impact Factor
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    ABSTRACT: To report the use of the second-generation Amplatzer Vascular Plug II (AVP II) for the treatment of a posttraumatic type A carotid-cavernous fistula (CCF). To achieve complete treatment of a CCF, the decision was taken to occlude the parent carotid artery after angiographic assessment. A 6-mm AVP II was deployed in the petrous segment of the ICA. Post-deployment angiography revealed minimal residual flow, so a first-generation AVP I was also deployed. Immediate flow cessation was achieved, without residual proximal or distal inflow from the contralateral side to the fistula. At 8 months, the size of the right cavernous sinus had significantly reduced, with complete occlusion of the ICA and no residual flow in the fistula. The AVP II may be a useful complementary device in the neurointerventional armamentarium for parent artery occlusion.
    Journal of Endovascular Therapy 08/2010; 17(4):564-8. · 2.70 Impact Factor
  • Nicolas A Diehm, Hanno Hoppe, Dai-Do Do
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    ABSTRACT: Ever since the first percutaneous transluminal angioplasty (PTA) was carried out in Switzerland in 1977, restenosis remains a major drawback of this minimally invasive treatment intervention. Numerous attempts to increase vessel patency after PTA have included systemic medications and endovascular brachytherapy, but these techniques have not met our expectations in preventing restenosis. Nitinol stents have been shown to reduce rates of restenosis and target lesion revascularization in patients undergoing endovascular treatment of long femoropopliteal obstructions. Despite further technical refinements in nitinol stent technology, restenosis occurs in approximately every third patient undergoing femoropopliteal stenting. Similarly, initial clinical trials with drug-eluting stents have failed to indicate restenosis inhibition in femoropopliteal segment. Unfortunately, restenosis rates after below-the-knee PTA and stenting have been reported to be even higher than those following femoropopliteal revascularization. Current concepts for the prevention and treatment of restenosis after PTA or stenting include the sustained release of antiproliferative paclitaxel into the vessel wall. Drug eluting balloons are a promising, novel technology aimed at inhibiting restenosis after PTA. Its clinical efficacy in reducing restenosis has already been proven for coronary arteries as well as for the femoropopliteal segment. The purpose of this article is to review the clinical utility of drug-eluting balloons for lower limb endovascular interventions.
    Techniques in vascular and interventional radiology 03/2010; 13(1):59-63.
  • Rofo-fortschritte Auf Dem Gebiet Der Rontgenstrahlen Und Der Bildgebenden Verfahren - ROFO-FORTSCHR RONTGENSTRAHL. 01/2010; 182.
  • Thoracic and Cardiovascular Surgeon - THORAC CARDIOVASC SURG. 01/2010; 58.
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    ABSTRACT: To prospectively compare the diagnostic accuracy of steady-state, high-spatial-resolution magnetic resonance (MR) angiography of the lower leg, performed with a blood pool contrast agent, with selective digital subtraction angiography (DSA) as the reference standard in patients with symptomatic peripheral arterial disease. Local ethics committee approval and written informed consent were obtained. In a nonrandomized trial, selective DSA and MR angiography were performed at 3.0 T with a blood pool contrast agent on 22 calves in 20 patients (mean age, 69.4 years +/- 11.3 [standard deviation]), 16 men (mean age, 67.8 years +/- 12.4) and four women (mean age, 75.6 years +/- 3.6 years), to evaluate 352 arterial segments. DSA and MR angiography were performed within 24 hours of each other and directly compared by three experienced, blinded radiologists by using high-spatial-resolution steady-state MR angiograms. Consensus reading for both DSA and MR angiography served as the reference standard. MR angiography was successful and occurred without serious adverse events in all patients. Seven significantly stenosed and 40 occluded segments were rated equally in both modalities. In three cases, the tibial arteries were shown to be occluded or significantly stenosed at DSA but appeared normal or significantly stenosed at MR angiography. The respective average segment sensitivity, specificity, and accuracy were 98.3% (59 of 60), 98% (113.7 of 116), and 98.1% (172.7 of 176) for DSA and 100% (60 of 60), 100% (116 of 116), and 100% (176 of 176) for MR angiography. Steady-state MR angiography was especially useful for the distal peroneal artery and the proximal anterior tibial artery. MR angiography performed with blood pool agents has an accuracy comparable with that of selective DSA in the lower leg but with less risk involved. Steady-state imaging performed with blood pool agents facilitates evaluation of MR angiography of infrapopliteal arteries.
    Radiology 10/2009; 253(3):879-90. · 6.34 Impact Factor
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    ABSTRACT: Acute type A aortic dissection is a serious emergency with a mortality rate of up to 40% within the first 24 h when left untreated. Surgical therapy needs to be initiated promptly. Due to this urgent situation, preoperative evaluation of the coronary arteries is not routinely performed in these patients. The aim of this study was to evaluate the accuracy of 64-slice computed tomography angiography (CTA) for postoperative coronary artery assessment in these patients. Ten consecutive patients with two or more cardiovascular risk factors were prospectively enrolled. Patients had type A aortic dissection treated surgically with a supracoronary graft of the ascending aorta. Performance of CTA to exclude significant stenosis (>50% lumen narrowing) and/or coronary artery dissection was compared with quantitative coronary angiography. A total of 147 segments were evaluated. Three segments (2%) were excluded from analysis. CTA correctly assessed one of three significant stenoses in three patients and correctly excluded coronary artery disease (CAD) in six of ten patients. One patient was rated false positive. Overall accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of CT for identifying coronary artery disease by segment was 98%, 33%, 99%, 50%, and 99%, respectively (P<0.05). By patient, it was 70%, 33%, 86%, 50%, and 75%, respectively. No coronary artery dissection was found. Noninvasive CTA may be a viable alternative to conventional angiography for postoperative coronary artery evaluation in patients with surgically treated type A aortic dissection and cardiovascular risk factors. An NPV of 99% should allow for reliable exclusion of CAD. Further studies with higher patient numbers are warranted.
    Emergency Radiology 09/2009; 17(3):185-90.

Publication Stats

542 Citations
156.56 Total Impact Points

Institutions

  • 2001–2011
    • Inselspital, Universitätsspital Bern
      • University Institute of Diagnostic, Interventional and Pediatric Radiology
      Berna, Bern, Switzerland
  • 2006–2008
    • Oregon Health and Science University
      • Dotter Interventional Institute
      Portland, OR, United States
    • Universität Bern
      Berna, Bern, Switzerland