European Multicenter Study for the Evaluation of a Dual-Layer Flow-Diverting Stent for Treatment of Wide-Neck Intracranial Aneurysms: The European Flow-Redirection Intraluminal Device Study.

BACKGROUND AND PURPOSE: Endoluminal reconstruction with flow-diverting stents represents a widely accepted technique for the treatment of complex intracranial aneurysms. This European registry study analyzed the initial experience of 15 neurovascular centers with the Flow-Redirection Intraluminal Device (FRED) system. MATERIALS AND METHODS: Consecutive patients with intracranial aneurysms treated with the FRED between February 2012 and March 2015 were retrospectively reviewed. Complications and adverse events, transient and permanent morbidity, mortality, and occlusion rates were evaluated. RESULTS: During the defined study period, 579 aneurysms in 531 patients (median age, 54 years; range, 13-86 years) were treated with the FRED. Seven percent of patients were treated in the acute phase (≤3 days) of aneurysm rupture. The median aneurysm size was 7.6 mm (range, 1-36.6 mm), and the median neck size 4.5 mm (range, 1-30 mm). Angiographic follow-up of >3 months was available for 516 (89.1%) aneurysms. There was progressive occlusion witnessed with time, with complete occlusion in 18 (20%) aneurysms followed for up to 90 ± 14 days, 141 (82.5%) for 180 ± 20 days, 116 (91.3%) for 1 year ± 24 days, and 122 (95.3%) aneurysms followed for >1 year. Transient and permanent morbidity occurred in 3.2% and 0.8% of procedures, respectively. The overall mortality rate was 1.5%. CONCLUSIONS: This retrospective study in real-world patients demonstrated the safety and efficacy of the FRED for the treatment of intracranial aneurysms. In most cases, treatment with a single FRED resulted in complete angiographic occlusion at 1 year.

[Inflammatory gastrointestinal diseases in children : Radiological diagnosis]. / Entzündliche gastrointestinale Erkrankungen bei Kindern : Radiologische Diagnose.

BACKGROUND/CLINICAL ISSUE: Inflammatory bowel diseases are frequently seen in the clinical routine of a pediatric radiologist. The timely diagnosis of inflammatory bowel diseases in children is particularly important in acute cases. STANDARD RADIOLOGICAL METHODS/METHODOLOGICAL INNOVATIONS: This nonsystematic article intends to give an overview of the radiologic imaging methods for the diagnosis and work-up of pediatric patients with inflammatory bowel diseases. PERFORMANCE: Ultrasound imaging is an important basis tool in pediatric clinical practice. However, sensitivity and specificity depends on the experience of the operator. Cross-sectional imaging modalities in pediatric patients with inflammatory bowel disease are performed only in exceptional cases when clinically justified. Dedicated computed tomography (CT) protocols for children are indispensable to lower radiation dose. ACHIEVEMENTS: Knowledge about particularities in inflammatory bowel diseases in pediatric patients and a rational approach to the use of radiological investigations in order to prevent the harmful effects of ionizing radiation are indispensable in dedicated pediatric imaging departments. PRACTICAL RECOMMENDATIONS: From a radiation-hygiene point of view, the clinical application of ultrasound imaging should be favored in the work-up of pediatric patients with inflammatory bowel diseases. Knowledge about advanced imaging procedures is essential particularly in imaging departments specialized in pediatric radiology.

Endovascular stroke therapy in Austria: a nationwide 1-year experience.

BACKGROUND AND PURPOSE: Based on a tight network of stroke units (SUs) and interventional centres, endovascular treatment of acute major intracranial vessel occlusion has been widely implemented in Austria. Documentation of all patients in the nationwide SU registry has thereby become mandatory. METHODS: Demographic, clinical and interventional characteristics of patients who underwent endovascular treatment for acute ischaemic stroke in 11 Austrian interventional centres between 1 October 2013 and 30 September 2014 were analysed. RESULTS: In total, 301 patients (50.5% women; median age 70.5 years; median National Institutes of Health Stroke Scale score 17) were identified.193 patients (64.1%) additionally received intravenous thrombolysis. The most frequent vessel occlusion sites were the M1 segment of the middle cerebral artery (n = 161, 53.5%), the intracranial internal carotid artery (n = 60, 19.9%) and the basilar artery (n = 40, 13.3%). Stent retrievers were used in 235 patients (78.1%) and adequate reperfusion (modified Thrombolysis in Cerebral Infarction scores 2b and 3, median onset to reperfusion time 254 min) was achieved in 242 patients (81.4%). Symptomatic intracranial haemorrhage occurred in 7%. 43.8% of patients (n = 132) had good functional outcome (modified Rankin Scale score 0-2) and the mortality rate was 20.9% (n = 63) after 3 months. Compared to the anterior circulation, vertebrobasilar stroke patients had higher mortality. Patients with secondary hospital transportation had better outcomes after 3 months than in-house treated patients. CONCLUSION: Our results document nationwide favourable outcome and safety rates of endovascular stroke treatment comparable to recent randomized trials. The ability to provide such data and the need to further optimize such an approach also underscore the contribution of respective registries.

Flat detector angio-CT following intra-arterial therapy of acute ischemic stroke: identification of hemorrhage and distinction from contrast accumulation due to blood-brain barrier disruption.

BACKGROUND AND PURPOSE: Flat panel detector CT in the angiography suite may be valuable for the detection of intracranial hematomas; however, abnormal contrast enhancement frequently mimics hemorrhage. We aimed to assess the accuracy of flat panel detector CT in detecting/excluding intracranial bleeding after endovascular stroke therapy and whether it was able to reliably differentiate hemorrhage from early blood-brain barrier disruption. MATERIALS AND METHODS: Seventy-three patients were included for retrospective evaluation following endovascular stroke therapy: 32 after stent-assisted thrombectomy, 14 after intra-arterial thrombolysis, and 27 after a combination of both. Flat panel CT images were assessed for image quality and the presence and type of intracranial hemorrhage and BBB disruption by 2 readers separately and in consensus. Follow-up by multisection head CT, serving as the reference standard, was evaluated by a single reader. RESULTS: Conventional head CT revealed intracranial hematomas in 12 patients (8 subarachnoid hemorrhages, 7 cases of intracerebral bleeding, 3 SAHs plus intracerebral bleeding). Image quality of flat panel detector CT was considered sufficient in all cases supratentorially and in 92% in the posterior fossa. Regarding detection or exclusion of intracranial hemorrhage, flat panel detector CT reached a sensitivity, specificity, positive and negative predictive values, and accuracy of 58%, 85%, 44%, 91%, and 81%, respectively. Maximum attenuation measurements were not valuable for the differentiation of hemorrhage and BBB disruption. CONCLUSIONS: Flat panel CT after endovascular stroke treatment was able to exclude the rare event of an intracranial hemorrhage with a high negative predictive value. Future studies should evaluate the predictive value of BBB disruptions in flat panel detector CT for the development of relevant hematomas.

Patient safety in interventional radiology: a CIRSE IR checklist.

Interventional radiology (IR) is an invasive speciality with the potential for complications as with other invasive specialities. The World Health Organization (WHO) produced a surgical safety checklist to decrease the morbidity and mortality associated with surgery. The Cardiovascular and Interventional Society of Europe (CIRSE) set up a task force to produce a checklist for IR. Use of the checklist will, we hope, reduce the incidence of complications after IR procedures. It has been modified from the WHO surgical safety checklist and the RAD PASS from Holland.

[Clinical application of flat-panel CT in the angio suite]. / Klinische Anwendung der Flachdetektor-CT im Angio-OP.

The introduction of flat-panel detectors in modern angiographic C-arm systems makes it possible to acquire CT-like images in the angiographic suite (flat-panel CT; FD-CT). In this review, after a short technical introduction of FD-CT including the discussion of the advantages and disadvantages of this new imaging modality, the most commonly and best evaluated indications for FD-CT will be described. FD-CT has become an important adjunctive imaging modality in neurointerventional procedures and embolizations, especially during liver embolization. Another attractive indication for FD-CT is musculoskeletal interventions. FD-CT may provide important additional information in complicated peripheral vascular interventions and stent-graft procedures. FD-CT has a broad spectrum of possible applications, which finally depends on the experience and innovative thinking of the operator. However, it has to be kept in mind that FD-CT causes additional radiation exposure. Roughly, it can be assumed that currently one FD-CT sequence causes at least the same radiation exposure as one spiral CT sequence of the corresponding body region.

MR angiographic follow-up of intracranial aneurysms treated with detachable coils: evaluation of a blood-pool contrast medium.

BACKGROUND AND PURPOSE: Blood-pool agents are promising in the imaging of small vessels with slow or complex flow. Our aim was to compare blood-pool contrast-enhanced MR angiography (BPCE-MRA) using gadofosveset trisodium (Vasovist) with 3D time-of-flight MRA (TOF-MRA) in the follow-up of intracranial aneurysms after endovascular therapy. MATERIALS AND METHODS: We included 32 patients with a total of 37 coiled aneurysms. MRAs in the early steady-state phase were performed on a 1.5T scanner within 8 days of digital subtraction angiography (DSA). Two radiologists independently analyzed TOF-MRA and BPCE-MRA images. Consensus was reached by review involving a third neuroradiologist. DSA images were interpreted separately by an interventional radiologist. Findings were assigned to 1 of 3 categories: 1) complete occlusion, 2) residual neck, and 3) residual aneurysm. RESULTS: Follow-up DSA demonstrated 13 complete obliterations (class 1), 13 residual necks (class 2), and 11 residual aneurysms (class 3). Weighted kappa statistics showed substantial concordance of TOF-MRA and DSA (0.664) as well as BPCE-MRA and DSA (0.724) ratings. Comparison between TOF-MRA and BPCE-MRA found excellent agreement (0.818) with only 6 (16.2%) discrepancies. For detecting residual flow, the difference in accuracy of both MRA techniques (83.8% versus 91.9%) was not significant (McNemar, P = 1.000). BPCE-MRA showed a tendency towards higher sensitivity and specificity (91.7% and 92.3%, respectively) compared with TOF-MRA (87.5% and 76.9%). CONCLUSIONS: In classifying the completeness of endovascular cerebral aneurysm therapy, we found that BPCE-MRA and 3D TOF-MRA showed very good agreement. The use of Vasovist did not lead to a significantly increased accuracy of MRA follow-up.

[Positron-emission tomography (PET) and PET/CT in head and neck cancer - recommendations of an interdisciplinary consensus conference]. / Positronen-Emissionstomografie (PET) und PET/CT bei Kopf-Hals-Tumoren - ein Vorschlag für einen interdisziplinären Konsensus.

BACKGROUND: Today's available therapeutic options in head and neck cancer patients have led to better treatment modalities tailored to the individually clinical staging of the patients towards a risk adapted tumour management. This, however, is only possible with an accurately pretherapeutic diagnostic regimen and closely posttherapeutic follow-up. METHODS: These issues were discussed by nuclear medicine experts, otorhinolaryngologists, oral surgeons, radiologists, radio-oncologists and oncologists in a meeting that took place in Pörtschach, Austria, on 05 May 2006. The aim was to discuss the impact and indications of performing FDG PET/CT in patients with head and neck cancer and to outline possible future perspectives. RESULTS: FDG PET/CT is recommended for a better pretherapeutic staging in stage IV according to UICC and should be the method of choice in CUP with lymph node metastases. FDG PET/CT should be performed 3 - 4 months after radiation-/radiochemotherapy to diagnose viable tumour and to avoid false positive results. To evaluate the position and effectiveness of FDG PET/CT in therapy-monitoring further studies are needed. In case of radiation therapy FDG PET/CT allows a tailored treatment of patients with an accurate design of the target volume to reduce damage to the surrounding tissues. CONCLUSIONS: The interdisciplinary consensus reached by the experts is not intended to recommend standard guidelines in the management of head and neck cancer but to summarise and stress the impact of FDG PET/CT on the basis of the present literature and current clinical practise.

[Brain tumors in childhood]. / Hirntumoren im Kindesalter.

Central nervous system (CNS) tumors are the most common solid neoplasms in childhood and the second most common malignancies after leukemia in the pediatric age group. Supratentorial tumors are more common in children younger than 2 years old and in adolescents, whereas in patients between 2 and 12 years of age brain tumors originating in the posterior fossa dominate. This implies a relationship between the type of tumor, its location and the age of the patient, which has to be considered in differential diagnoses. Medulloblastoma represents the most common malignant brain tumor in childhood. In the posterior fossa medulloblastomas are approximately as frequent as astrocytomas. Supratentorial astrocytomas are by far the main tumor type. In this report some typical CNS neoplasms in children are discussed and their neuroradiological features are demonstrated.

[Flat-panel CT as a new perinterventional imaging modality in aortic stentgraft procedures--work in progress]. / Flachdetektor-CT als ergänzende Untersuchung bei der endoluminalen Behandlung von thorakalen und abdominellen Aortenaneurysmen--Erste klinische Erfahrungen.

PURPOSE: To evaluate the value of flat-panel CT (FP-CT) as a new perinterventional imaging modality in aortic stentgraft procedures. MATERIALS AND METHODS: FP-CT was performed in 21 patients (19 males, mean age 77, range 54 to 90) from June 2005 to February 2007 immediately after endovascular treatment of thoracic and abdominal aortic aneurysms on the angiographic table. Nine thoracic aortic aneurysms were treated with Zenith-endoprosthesis. Nine of twelve abdominal aortic aneurysms were treated with Zenith-endoprosthesis and three with an Excluder-endoprosthesis. Images were acquired with a rotating C-arm and the following parameters: during an acquisition time of 20 seconds and at a rotation of 217 degrees, 538 projections were acquired. Contrast agent was administered in 14 patients. Images were displayed in MIP, MPR and VRT mode. RESULTS: In all patients the stentgraft was shown exactly and the alignment of the prosthesis along the landing zones was well displayed. The aneurismal sack was well shown in all patients. 1 x an endoleak II was detected, 1 x an angiographically verified endoleak I was not detected. In one patient distal extension was considered due to suspected short stentgraft at the distal neck. Flat-panel CT showed sufficient neck coverage and no extension was inserted. Due to artifacts of the prosthesis, the platinum markers and the guide wire as well as due to pulsation of the aorta, the resolution of detail decreased and reduced the visualization of the alignment. CONCLUSION: FP-CT is a promising tool and may provide additional information, but further studies are necessary to define the value of flat-panel CT in thoracic and abdominal aortic stentgraft procedures.

Accidental transtumoral microparticle embolization of eloquent brain areas in a case of large temporofrontal meningioma.

SUMMARY: We report a case of transtumoral diapedesis of microparticles during preoperative embolization of a large symptomatic temporofrontal meningioma, resulting in severe neurological deficit. In retrospective analysis of angiographic images, the pattern of supply to the tumour was found to be predictive for wide anastomotic channels connecting the dural and pial supply, thereby increasing the risk of the procedure. Recognising this pattern can prevent this rare cause of complication in a still controversial procedure.

Sentinel node SPECT-CT in breast cancer. Can we expect any additional and clinically relevant information?

UNLABELLED: The AIM of this study was to determine the additional value of SPECT/CT in sentinel node scintigraphy in breast cancer. Furthermore, it was our question to determine, whether the low-dose computed tomography component (LD-CT) can be used for axillary lymph node staging of clinically negative patients. PATIENTS, METHODS: 51 patients with invasive breast cancer <3 cm in diameter were included in our prospective investigation. SPECT/CT was performed on a dedicated scanner 30 minutes after subareolar injection of (99m)Tc-Nanocoll. Axillary staging with CT(LD) was performed using standard CT-criteria. SLN were allocated to an axillary level using SPECT alone and SPECT/CT. Additionally, the number of SLN on CT(LD) corresponding to the scintigraphic hot node was notified for each patient and compared to the number of SLN found with the gamma probe. RESULTS: In 45/51 evaluable patients SLN could be localised in level I in 43 patients and in level II in two patients (all positive) using SPECT-CT, whereas a clear allocation could not be obtained by SPECT alone. The number of SLN was discrepant between SPECT and CT(LD) in 13/45 patients. The number of SLN detected with the gamma probe (n = 68) not significantly differed from the number of SLN detected by CT(LD) (n = 65) but was significantly higher than with SPECT (n = 51). CT(LD) yielded a sensitivity of 35.7%, a specificity of 83.9%, a positive predictive value (PPT) of 50%, a negative predictive value (NPV) of 74.3% and a diagnostic accuracy of 68.9% for axillary staging with CT(LD). CONCLUSION: The additional information of SPECT/CT allows a more accurate characterization of the SN concerning size, depth and anatomical location. CT(LD) when performed during (99m)Tc-Nanocoll sentinel-SPECT/CT is not suitable for axillary staging in breast cancer patients with clinical negative axilla due to its low sensitivity and moderate specificity. Therefore, it does not influence the decision for SNB or ALND. The limited resolution of SPECT leads to an underestimation of the number of SLN compared to CT(LD) and the gamma probe.

Observations on the failure of stent-grafts in the aortic arch.

INTRODUCTION: The results of endovascular stent-grafts in the abdominal aorta and descending thoracic aorta have been encouraging. Expanding the use of thoracic stent-grafts in to the aortic arch has been associated with increasing numbers of complications. Recently isolated cases of stent-graft collapse have been reported. METHODS: This was a multi-centre European case series. Data was collected retrospectively on seven patients from five experienced endovascular centres with thoracic stent-graft collapse. RESULTS: Of the seven patients four were treated for traumatic aortic rupture. Six were male, median age 33 (range 17-54) years. During the ensuing 2 months all patients suffered stent-graft collapse. This was symptomatic in 3 patients and the rest were identified on CT. Endovascular management was possible in 6/7 patients using either a balloon expandable stent (n=6) or further stent-graft (n=1). Two patients had persistent type I endoleak despite treatment. Two of the 7 patients died, both of which presented with symptomatic thoracic stent-graft occlusion. Both deaths were a direct result of stent-graft collapse. CONCLUSIONS: Thoracic stent-graft collapse may be asymptomatic underscoring the importance of stent-graft surveillance. Endovascular management of collapse is possible in most cases using a large balloon expandable stent. Symptomatic collapse is associated with high morbidity and mortality.

[Sonography of the scrotum]. / Sonographie des Skrotalinhalts.

Ultrasonography (US) has become the method of choice for imaging in diseases affecting the scrotum. With the development of high resolution transducers using colour Doppler and pulsed Doppler, it is now possible to make accurate diagnoses. Sonography is able to distinguish immediately between intra- and extratesticular lesions. It is also possible to differentiate between cystic and solid tumours. Solid testicular tumours may be detected without difficulty and thus the patient's dignity is practically assured (98 % of solid testicular tumours are malignant). In cases of acute diseases of the scrotum, sonography nearly always permits a differentiation between torsion and inflammation, thus avoiding the risk of unnecessary operations. The review covers the introduction, anatomy, the scanning protocol for scrotal ultrasound and pathological changes. Testicular tumours and torsion are discussed in detail. Variations from the norm and pitfalls are outlined so as to help avoid making misdiagnoses.

Clinical experience with a commercially available negative oral contrast medium in PET/CT.

PURPOSE: To evaluate a commercially available negative oral contrast material for PET/CT. MATERIAL AND METHODS: In a prospective series of 49 patients, Mukofalk, which is a vegetarian-based substance, was used as a negative oral contrast medium in whole body PET/CT studies. Mukofalk was administered during a time period of 1.5 hours before the examination. Quality of small bowl distension and eventual pathological tracer uptake in the intestine were evaluated. RESULTS: Distension of the small bowel was excellent or good in 41 (85 %) and poor in 8 (15 %) patients. Mild tracer uptake in the small bowel was observed in 5 patients (10.2 %) and moderate uptake in another 2 patients (4 %). In none of these patients did the F-18 FDG uptake interfere with image interpretation. CONCLUSION: Mukofalk can be used as a negative oral contrast medium in PET/CT studies.

Review of source images is necessary for the evaluation of gadolinium-enhanced MR angiography for renal artery stenosis.

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 post-processed 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 (> or =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< kappa< or = 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.