Magnetic Resonance (MR) Imaging-guided High Intensity focused Ultrasound (MRgHIFU) is a non-invasive, non-ionizing thermal ablation therapy that is particularly interesting for the palliative or curative treatment of musculoskeletal tumors. We introduce a new modular MRgHIFU device that allows the ultrasound transducer to be positioned precisely and interactively over the body part to be treated. A flexible, MR-compatible supporting structure allows free positioning of the transducer under MRI/optical fusion imaging guidance. The same structure can be rigidified using pneumatic depression, holding the transducer rigidly in place. Targeting accuracy was first evaluated in vitro. The average targeting error of the complete process was found to be equal to 5.4 ± 2.2 mm in terms of focus position, and 4.7° ± 2° in terms of transducer orientation. First-in-man feasibility is demonstrated on a patient suffering from important, uncontrolled pain from a bone metastasis located in the forearm. The 81 × 47 × 34 mm 3 lesion was successfully treated using five successive positions of the transducer, under real-time monitoring by MR Thermometry. Significant pain palliation was observed 3 days after the intervention. The system described and characterized in this study is a particularly interesting modular, low-cost MRgHIFU device for musculoskeletal tumor therapy.

Objectives. - To estimate the intra-and inter-rater consistency of radiologist and neurologist working in pairs attributing DWI-ASPECTS (Diffusion Alberta Stroke Program Early CT Score) in patients with acute middle cerebral artery ischemic stroke referred for mechanical thrombectomy, intravenous thrombolysis or bridging therapy. Methods. - Five neurologists and 5 radiologists working in pairs and in hour period scored independently and in two reading sessions anonymized DWI-ASPECTS of 80 patients presenting with acute anterior ischaemic stroke in our center. We measured agreement between pairs using intraclass correlation coefficients (ICCs). A Fleiss kappa was used for dichotomized (0-6;7-10) and trichotomized (0-3;4-6;7-10) ASPECTS. The interrater distribution of the score in the trichotomized (0-3;4-6;7-10) ASPECTS was calculated. We determined the interrater (Cohen kappa) and intrarater (Fleiss kappa) agreement on the ASPECTS regions. Results. - The average DWI-ASPECTS was 6.35 (SD +/- 2.44) for the first reading, and 6.47 (SD +/- 2.44) for the second one. The ICC was 0.853 (95%CI, 0.798-0.896) for the interrater, and 0.862 (95%CI, 0.834-0.885) for the intrarater evaluation. Kappa coefficients were high for dichotomized (k = 0.75) and trichotomized (k = 0.64) ASPECTS. Evaluators agreement on the ASPECTS category (0-3), (4-6) and (7-10) was 88, 76 and 93% respectively. The anatomic region infarcted was well identified (k = 0.70-0.77), except for the internal capsula (k = 0.57). Inter rater agreement was fair for M5 (k = 0.37), moderate for internal capsula (0.52) and substantial for the other regions (0.60-0.79). Conclusions. - Reliability of DWI-ASPECTS is good when determined by radiologist and neurologist working in pairs, which corresponds to our current clinical practice. However, discrepancies are possible for cut-off determination, which may impact the indication of thrombectomy, and for the determination of the exact infarcted region. Agreement to propose category (4-6) is lower than for (0-3) and (8-10) ASPECTS categories. @2021 Elsevier Masson SAS. All rights reserved.

This report describes an unusual vertebral artery cement embolization during C3 transpedicular vertebroplasty performed under computed tomography (CT) guidance and fluoroscopy. The Institutional Review Board approved this case report, and the patient’s consent for publication was obtained. A 54-year-old woman with an invasive lobular breast carcinoma suffered from cervical pain. A CT scan showed spinal osteolytic lesions. A thoracic vertebral biopsy confirmed the diagnosis of breast cancer metastasis. C3 vertebroplasty was indicated for pain and lysis of the posterior wall of C3 (Fig 1). The vertebroplasty was performed under general anesthesia in a combined CT-equipped fluoroscopy suite. CT guidance (Somatom Definition Edge; Siemens Healthineers, Forchheim, Germany) was used to guide needle placement, and lateral-view fluoroscopy was used for cement injection. Antibiotic prophylaxis was not administered. A 13-gauge cutting cannula (Madison Mini, 13 ga, 6 cm length; Merit Medical Systems, South Jordan, Utah) was placed through the left transpedicular route. A bone biopsy needle (1.85 mm diameter, 14 cm length) was placed at the anterior part of the vertebral body (Fig 2). Under lateral-view real-time fluoroscopy, cement (Vertaplex HV; Stryker, Duisburg, Germany) was injected through the biopsy needle (0.62 cm3, 30% of the volume of the lytic corporeal lesion). A CT scan centered on C3 showed a left paravertebral leak initially interpreted to be venous. The leak was not visible under fluoroscopy. On the CT scan, the cement leak joined the left vertebral foramen in the form of a thin thread. CT angiography of the head and neck was then performed, showing cement in the V3 segment of the left vertebral artery (Figs 3, 4). The vertebral artery was not occluded, and no intracranial cement embolus was visible. No additional cement was injected. In the recovery room, the patient was asymptomatic. She was transferred to a neurovascular inpatient unit and treated with 100 mg of acetylsalicylic acid. The next day, magnetic resonance (MR) imaging showed two acute punctiform ischemic lesions in the left cerebellar hemisphere (Fig 5). No intracranial arterial occlusion was seen. She was discharged the next day without any neurologic deficits and without cervical pain. One month later, she presented with headaches and nausea. On MR imaging, fluid-attenuated inversion recovery (FLAIR) images showed diffuse cerebellar hyperintensity, not present on the prior MR imaging. Cerebellar leptomeningeal enhancement suggested leptomeningeal carcinomatosis (Fig 6). The patient died 6 months later from progression of the leptomeningeal carcinomatosis.Figure 3Coronal reconstruction of an intraprocedural computed tomography scan after injection of cement showed the spontaneous left lateral hyperdensity following the expected course of the vertebral artery (arrow).View Large Image Figure ViewerDownload Hi-res image Download (PPT)Figure 4Computed tomography angiography maximum intensity projection demonstrated the cement leak in the V3 segment of the left vertebral artery (white arrows). The initial paravertebral leak alerting the radiologist (open arrow) appeared denser than the enhanced blood.View Large Image Figure ViewerDownload Hi-res image Download (PPT)Figure 5One day after the procedure, diffusion-weighted imaging magnetic resonance imaging showed an ischemic lesion in the left cerebellum (arrow).View Large Image Figure ViewerDownload Hi-res image Download (PPT)Figure 6One month after the procedure, axial contrast-enhanced T1-weighted magnetic resonance imaging showed leptomeningeal enhancement corresponding to carcinomatosis (yellow oval).View Large Image Figure ViewerDownload Hi-res image Download (PPT) Recent retrospective studies present cervical vertebroplasty as a safe and effective technique for pain relief (1Clarençon F. Fahed R. Cormier E. et al.Safety and effectiveness of cervical vertebroplasty: report of a large cohort and systematic review.Eur Radiol. 2020; 30: 1571-1583Crossref PubMed Scopus (10) Google Scholar,2Cazzato R.L. de Marini P. Auloge P. et al.Percutaneous vertebroplasty of the cervical spine performed via a posterior trans-pedicular approach.Eur Radiol. 2021; 31: 591-598Crossref PubMed Scopus (9) Google Scholar). Common vertebroplasty approaches used for cervical vertebrae include transoral for the C2 level and anterolateral for the other cervical levels. An alternative is the posterior transpedicular approach (2Cazzato R.L. de Marini P. Auloge P. et al.Percutaneous vertebroplasty of the cervical spine performed via a posterior trans-pedicular approach.Eur Radiol. 2021; 31: 591-598Crossref PubMed Scopus (9) Google Scholar). A common vertebroplasty adverse event is extraosseous cement leakage, which is often of no clinical significance. Even if venous cement migration may lead to pulmonary embolism, it is also usually well tolerated (3Wang L. Yang H. Shi Y. Jiang W.M. Chen L. Pulmonary cement embolism associated with percutaneous vertebroplasty or kyphoplasty: a systematic review.Orthop Surg. 2012; 4: 182-189Crossref PubMed Scopus (101) Google Scholar). A rarer adverse event is direct arterial cement migration. At the cervical level, direct cement leakage into the vertebral artery (4Beji H. Menassel B. Sadoune K. Mavrovi E. Pilleul F. Mastier C. A rare complication of percutaneous transoral vertebroplasty at C2: cement leakage within the vertebral artery.J Vasc Interv Radiol. 2017; 28: 1302-1304Abstract Full Text Full Text PDF PubMed Scopus (5) Google Scholar) and resultant vertebrobasilar stroke have been reported (1Clarençon F. Fahed R. Cormier E. et al.Safety and effectiveness of cervical vertebroplasty: report of a large cohort and systematic review.Eur Radiol. 2020; 30: 1571-1583Crossref PubMed Scopus (10) Google Scholar). The clinical evolution of the patient presented several teaching points. First, potential intra-arterial migration must be considered by the interventional radiologist, who must track it down at any stage of the cement injection, and promptly stop the injection for any suspicions. Only CT allowed the visualization of the fine track of cement, and a contrast-enhanced CT scan confirmed the intra-arterial location of the cement. Second, the injection of cement, particularly through a fine needle, may have facilitated retrograde cement migration into the vertebral artery via the vertebral sinusoids. Intratumoral arteriovenous shunting is also a previously reported hypothesis, but arterial cement migration has also been described in the setting of vertebroplasty for osteoporotic fracture without tumor metastases (5Matouk C.C. Krings T. Ter Brugge K.G. Smith R. Cement embolization of a segmental artery after percutaneous vertebroplasty: a potentially catastrophic vascular complication.Interv Neuroradiol. 2012; 18: 358-362Crossref PubMed Scopus (19) Google Scholar). Third, we assumed that the stroke was the direct consequence of the cement leakage into the vertebral artery. The stroke may have been due to the migration of cement, thrombus, bone marrow, or tumor cells into the superior cerebellar artery. Fourth, the leptomeningeal carcinomatosis may have been the consequence of the vertebral artery cement migration. The chronology of these events and the cerebellar localization of the carcinomatosis suggest this relation. Tumor cell embolization may have occurred before or during intra-arterial cement migration. Mohme et al (6Mohme M. Riethdorf S. Dreimann M. et al.Circulating tumour cell release after cement augmentation of vertebral metastases.Sci Rep. 2017; 7: 7196Crossref PubMed Scopus (33) Google Scholar) showed that cement augmentation of spinal metastases can lead to the release of tumor cells into the bloodstream. However, no human studies have proven that released tumoral cells have the capacity to form distant metastases. In summary, this report describes a woman with osteolytic breast cancer metastases whose C3 level vertebroplasty was complicated by direct vertebral artery cement leakage. An asymptomatic cerebellar stroke was detected immediately, and cerebellar leptomeningeal carcinomatosis was observed 1 month later. Interventional radiologists performing cervical vertebroplasty should be aware of the risk of potentially catastrophic cement leakage into the vertebral artery, and in the setting of treating malignant vertebral targets, the possible linkage between cervical vertebroplasty and leptomeningeal carcinomatosis. For cervical vertebroplasty, intraprocedural CT scanning appears to be essential.

A 50-year-old man with a history of IV drug use and cervical scars presented with acute disorientation and incoherent speech. A cerebral CT demonstrated a left middle cerebral artery (MCA) infarct with intracranial linear hyperdensity (figure, A). CT angiography revealed a broken needle in the left internal and external carotid arteries (figure, B); there was apparent needle migration into the MCA (figure, B). No MRI was performed; the magnetic field may have moved the intracranial needle. Cervical needle fragments were removed surgically. Broken needle cardiac embolization associated with IV drug use has been reported,(1,2) but intracranial arterial migration is exceptional.

In time of SARS-Cov2 pandemic, neurologists need to be vigilant for cerebrovascular complications of Covid-19. We present a case of bilateral occipito-temporal infarction revealed by a sudden cortical blindness with haemorrhagic transformation after intravenous thrombolysis in a diabetic patient infected by Covid-19. Differential diagnoses are discussed in front of this unusual presentation and evolution.

To report prospectively the effect of erikson hypnoanalgesia and musical background on procedural medication and well-being in patients undergoing cimentoplasty on prone position. All the patients (n = 118, mean age 68.9 ± 13.3 years) had an IV injection of paracetamol (1 g) and midazolam (0.5 mg) and a local anesthesia before the cimentoplasty. Hypnoanalgesia (H) was proposed in consultation and performed if the technician was available. Three groups were compared: group hypnoanalgesia (H), music (M) or control (C). Numbers of lumbar or thoracic levels was 1 to 4. The necessity to add medication during the treatment was evaluated. The procedural well-being (0-incomfortable- to 10-comfortable) was asked 2 hours after the cimentoplasty. Duration of the procedure, hearth rate and arterial pressure during cimentoplasty were notified. Thirty-three patients were included in the group (H), 38 in (M) and 47 in (C). The mean number of levels was 1.61, 1.53 and 1.66 for groups (H), (M) and (C) respectively. 18.2% of patients in (H), 29% in (M) and 40.4% of patients in (C) had an adjunctive medication during the treatment (P = 0.101) for a well-being state of 7.5 ± 2.3, 7.1 ± 2 and 6.9 ± 2 respectively (P = 0.381). Time durations were 49.8, 44.1 and 46.4 min for group (H), (M) and (C) respectively. No significative difference of cardiac frequency, arterial pressure was observed during the cimentoplasty between the three groups. The best reduction of painfulness was reached under hypnoanalgesia, allowing less injection of adjunctive medication during the treatment for an equivalent comfort. Musical background is also an interesting way to improve the comfort of patients undergoing cimentoplasty in prone position.

Purpose: To evaluate the accuracy of a fusion imaging guidance system using ultrasound (US) and computerized tomography (CT) as a real-time imaging modality for the positioning of a 22-gauge needle in the liver. Materials and Methods: The spatial coordinates of 23 spinal needles placed at the border of hepatic tumors before radiofrequency thermal ablation were determined in 23 patients. Needles were inserted up to the border of the tumor with the use of CT-US fusion imaging. A control CT scan was carried out to compare real (x, y, z) and virtual (x', y', z') coordinates of the tip of the needle (D for distal) and of a point on the needle located 3 cm proximally to the tip (P for proximal). Results: The mean Euclidian distances were 8.5+/-4.7 mm and 10.5+/-5.3 mm for D and P, respectively. The absolute value of mean differences of the 3 coordinates (vertical bar x' -x vertical bar, vertical bar y' - y vertical bar and vertical bar z' - z vertical bar) were 4.06 +/- 0.9, 4.21 +/- 0.84, and 4.89 +/- 0.89 mrn for D and 3.96+/-0.60, 4.41 +/- 0.86, and 7.66 +/- 1.27 mm for P. X= vertical bar x' - x vertical bar and Y = vertical bar y' - y vertical bar coordinates were <7 mm with a probability close to 1. Z = vertical bar z' - z vertical bar coordinate was not considered to be larger nor smaller than 7 mm (probability >7 mm close to 50%). Conclusions: Positioning errors with the use of US-CT fusion imaging used in this study are not negligible for the insertion of a 22-gauge needle in the liver. Physicians must be aware of such possible errors to adapt the treatment when, used for thermal ablation.

To evaluate the impact of the ultrasound (US) focusing on the thermal curves in an in vitro (bone and cement) and in vivo experiment [1]. To compare these results with the acoustic and thermal simulation results [2], [3]. To evaluate the US field distortion secondary to dissection needles. MRgHIFU sonications were performed on a bone marrow (F = 1 MHz, P = 25 W during 90 s), on the ilium of a pig (in vivo) (F = 1 MHz, P = 79 W during 40 s) and a specimen of cement (F = 2.7 MHz, P = 20 W during 45 s). Focusing was superficial (at the periosteum or on the cement), deep (in the marrow or behind the cement) or intermediate (cortical bone). An acoustic and thermal simulation (k-wave) was performed using the same model of bone marrow with two values of bone acoustic absorption coefficient (α = 4.7 et 9.9 dB/cm) and compared with the MRI thermometry. For spinal and pelvic lesions, a dissection may be necessary to protect nerves during thermal ablation [4]: therefore, the impact of dissection needles (22 to 13-gauge) on the US field was evaluated. A vaster and higher periosteal heating was observed with deep sonication (Fig. 1). The lateral and vertical heating tended to appear with a delay, which can be explained by thermal inertia. These results were best reproduced with the simulation for α=4.7 dB/cm. Simulation with α = 9.9 dB/cm showed a much higher periosteal heating and different thermal curves. Cement and in vivo thermal curves were similar to the bone marrow results. No US field distortion was observed with 22 to 18-gauge needles. For the treatment of painful bone metastases, deep focusing may be the most efficient. Simulations can reproduce the in vitro results. However, simulation results depend on tumoral bone α which remains difficult to measure. For spinal or pelvic lesions thermal ablation requiring a protection of neural structures [5], dissection needles may be placed in the HIFU cone without any consequence at the condition that the liquid injected does not spread in front the US.

L’hypnoanalgésie a pour objectif de diminuer la pénibilité d’un geste invasif. Son utilisation a été rapportée dans les gestes de cardiologie, radiologie interventionnelle vasculaire ou percutanée. Dans cette étude monocentrique prospective non randomisée, la pénibilité de la cimentoplastie (os tumoral ou ostéoporotique), effectuée en procubitus chez les patients accompagnés par hypnoanalgésie (groupe H) était comparée à celle ressentie sans hypnoanalgésie (groupe SH). L’hypnoanalgésie était proposée en consultation et réalisée si le manipulateur formé à l’hypnose ericksonienne était présent le jour du geste. Tous les patients bénéficiaient d’une anesthésie locale (AL), d’une injection d’1 g de paracétamol et 0,5 mg de midazolam. Le bien-être durant le geste (de 0 « très inconfortable à 10 « très confortable », évalué 2 h post-procédure), le rajout d’un traitement (midazolam ou protoxyde d’azote [NO]) ainsi que les variations de TA et de FC pendant le geste ont été mesurés. Vingt-cinq patients (1 [12] ou 2 [13] localisations) ont été inclus dans le groupe H et 39 (1 [19], 2 [13], 3[5] ou 4 [2] localisations) pour le groupe SH. Vingt-quatre (96 %) lésions étaient tumorales dans le groupe H et 34 (87,2 %) dans le groupe SH. L’état de bien-être était de 7,3 ± 2,3 et 6,9 ± 1,7 dans les groupes H et SH respectivement (p = 0,242), pour des durées de traitement de 48,5 ± 17,9 min pour le groupe H et 46,8 ± 16,7 min pour le groupe SH. 16 % des patients dans le groupe H et 38,5 % dans le groupe SH ont bénéficié d’un complément d’anxiolytique/antalgique ou de NO (p = 0,055). 92 % des patients pensent que l’H a diminué la pénibilité du geste. Il n’a pas été observé de variations significatives de FC ou TA durant les gestes. L’hypnoanalgésie diminue la pénibilité de la cimentoplastie, ce qui se traduit essentiellement par une moindre quantité d’anxiolytique/antalgique ou de NO administrés pour un état de confort identique à celui rapporté sous AL.

Les ultrasons focalisés à haute énergie (HIFU) sont une technique prometteuse d’ablation dite non invasive. Ils consistent à appliquer une énergie acoustique sur une lésion alors détruite par effet thermique. Son utilisation sur les lésions osseuses a été rapporté mais des interrogations subsistent, en particulier pour les localisations du squelette axial. La localisation, le volume, la matrice, l’environnement anatomique des ostéomes ostéoïdes (OO) et des métastases osseuses traités par ablation percutanée entre octobre 2014 et octobre 2016 ont été analysés. Trois catégories ont été définies : – HIFU peut être réalisé seul ; – HIFU peut être réalisé avec une protection thermique de structures nerveuses ; – HIFU n’est pas une option envisageable. Au total, 112 lésions (71 métastases et 41 OO) ont été analysées. Les lésions étaient localisées dans le pelvis (28), les membres (37), le rachis ou le sacrum (35), les côtes (10) et le sternum (2). Au total, 33 (80,5 %) des OO (volume moyen : 0,7 cm3) étaient considérés comme traitables par HIFU seuls (46,3 %) ou avec dissection (34,2 %). La matrice des OO était sclérotique (13), lytique (12) ou mixte (8). Au total, 51 (71,8 %) des métastases (volume moyen 43,7 cm3) étaient considérés traitables par HIFU seuls (35,2 %) ou avec dissection et/ou consolidation (36,6 %). La matrice des métastases était sclérotique (9), lytique (20) ou mixte (22). La majorité des lésions du pelvis (96,4 %) ou des membres (91,9 %) étaient possiblement traitables par HIFU alors que 68,6 % des lésions rachidiennes ou sacrées n’étaient pas accessibles à un traitement par HIFU. Au-delà de la question de l’efficacité, celle de la sûreté des HIFU dans l’ablation des lésions osseuses mérite d’être posée, en particulier pour les lésions du squelette axial : en effet, il peut être difficile de protéger les structures nerveuses, du fait de leur proximité immédiate avec la cible mais aussi de l’encombrement du transducteur ne permettant pas l’insertion des aiguilles de dissection.

Purpose: To retrospectively evaluate the suitability of MRgHIFU for osteoid osteomas (OOs) and bone metastases in patients who underwent minimally-invasive percutaneous thermal ablation. Materials and methods: One hundred and sixty-seven lesions (115 metastases and 52 OOs) treated percutaneously between October 2014 and June 2017 were retrospectively analyzed. Tumors were located in the spine or sacrum (54), pelvis (43), limbs (50), ribs (17) and sternum (3). Tumor volume, matrix, anatomical environment and need for protection of surrounding structures or consolidation were assessed. Cases were classified into three categories: (a) lesions suitable for MRgHIFU therapy alone; (b) lesions suitable for MRgHIFU if protection of surrounding structures and/or bone consolidation is performed; (c) lesions not suitable for MRgHIFU. Results: Twenty-six (50%) of OOs were classified as suitable for MRgHIFU alone and 17 (32.7%) as suitable for MRgHIFU with hydro-dissection. Matrix of treatable OOs was sclerotic (19), lytic (15) or mixed (9), with mean volume 0.56 cm(3). Forty-one (35.7%) of metastases were classified as suitable for MRgHIFU alone and 43 (37.4%) as suitable with hydro-dissection and/or consolidation. Matrix of metastases was sclerotic (13), lytic (37) or mixed (34), with mean volume 71.9 cm(3). Mean depth of targetable lesions was 50.9 +/- 28.4 mm. 97.7% of pelvic lesions and 94% of peripheral bone lesions were targetable by HIFU. 66.6% of spinal or sacral lesions were considered untreatable. Conclusion: MRgHIFU cannot be systematically performed non-invasively on bone tumors. Combination with minimally-invasive thermo-protective techniques may increase the number of eligible cases.

L’Alberta Stroke Program Early CT Score (ASPECTS) est un score scannographique prédictif de récupération et d’hémorragie symptomatique après recanalisation dans les infarctus cérébraux de la circulation antérieure en phase aiguë. Étendu à l’IRM de diffusion (DWI-ASPECTS), il se présente comme une alternative au calcul du volume ischémié. Malgré son utilisation dans les études cliniques sur la thrombectomie, il persiste des incertitudes sur sa reproductibilité. L’objectif de notre travail est d’évaluer la reproductibilité inter- et intra-individuelle du DWI-ASPECTS par 5 binômes radiologue/neurologue impliqués dans la prise en charge de l’AVC ischémique dans notre établissement. Au total, 80 dossiers d’imagerie (Magnetom Aera, Siemens, 1,5 T) ont été inclus à partir d’un registre prospectif, comportant tous les patients pris en charge pour thrombolyse au centre hospitalier Annecy-Genevois (CHANGE) de janvier 2014 à novembre 2016. Cinq couples d’évaluateurs ont analysé les 80 IRM à 2 reprises, à 3 semaines d’intervalle, afin de coter le DWI-ASPECTS pour chacune d’elle. La reproductibilité a été estimée en utilisant le coefficient de corrélation inter-classe (ICC) et le kappa de Fleiss pour une analyse catégorielle (0–6 ; 7–10) et (0–3 ; 4–6 ; 7–10). Nous avons observé d’excellentes corrélations inter-observateurs (ICC = 0,853) et intra-observateurs (ICC = 0,862). Lors de l’analyse catégorielle, on retrouve une concordance importante que le score soit dichotomisé (k = 0,75) ou trichotomisé (k = 0,64). Notre travail confirme que le score DWI-ASPECTS est un outil reproductible en intra- et inter-observateurs. Il persiste des incertitudes sur les cutoff préalablement établis, car des variations d’un ou deux points autour d’une valeur seuil pourraient modifier à tort une décision thérapeutique. Il semble donc licite d’utiliser ce score avec précaution, en prenant soin de l’intégrer à un faisceau d’arguments clinico-radiologiques afin d’optimiser le choix thérapeutique.

RADIOLOGIE ET IMAGERIE MEDICALE : Musculosquelettique - Neurologique - Maxillofaciale - 31-661-A-15

RADIOLOGIE ET IMAGERIE MEDICALE : Musculosquelettique - Neurologique - Maxillofaciale - 31-661-A-10

RADIOLOGIE ET IMAGERIE MEDICALE : Musculosquelettique - Neurologique - Maxillofaciale - 31-661-A-15

Background. - Since 2015, the emergence of mechanical thrombectomy as standard care in acute stroke has involved organizational changes not only for stroke centers, but also for entire emergency regional networks. The aim of our study was to assess the proportion of ischemic stroke patients, admitted to stroke units in the Northern French Alps within the first 6 h of onset, eligible for thrombectomy.Methods. - This study retrospectively analyzed the clinical and radiological data of all acute stroke patients hospitalized at three stroke units of the Northern French Alps Emergency Network (RENAU) in 2014. Eligible patients had proximal arterial occlusions of the anterior and posterior cerebral circulation, as confirmed by brain imaging, which could be treated by thrombectomy within 6 h of symptom onset.Results. - Of the 435 cases of acute ischemic stroke, 152 patients were treated by intravenous thrombolysis (IV rtPA). Of these patients, 83 (55%) had intracranial occlusions and were eligible for combined thrombectomy. Of the 283 patients not treatable by IV rtPA, 32 patients (11%) were eligible for primary thrombectomy.Conclusion. - Thrombectomy could be performed in 26% of our acute ischemic stroke patients (n = 115/435), and a large increase in endovascular procedures is expected over the next few years that will require close collaboration among all partners in the emergency networks. Using our RENAU stroke database, it will be possible to compare various factors contributing to effective activity. (C) 2017 Elsevier Masson SAS. All rights reserved.

OBJECTIVE Endovascular treatment of aneurysms may result in incomplete initial occlusion and aneurysm recurrence at angiographic follow-up studies. This study aimed to assess the feasibility and efficacy of bipolar radiofrequency ablation (RFA) of aneurysm remnants after coil embolization. METHODS Bipolar RFA was accomplished using the coil mass as 1 electrode, while the second electrode was a stent placed across the aneurysmal neck. After preliminary experiments and protocol approval from the Animal Care committee, wide-necked bifurcation aneurysms were constructed in 24 animals. Aneurysms were allocated to 1 of 3 groups: partial intraoperative coil embolization, followed by RFA (n = 12; treated group) or without RFA (n = 6; control group 1); or attempted complete endovascular coil embolization 2-4 weeks later (n = 6; control group 2). Angiographic results were compared at baseline, immediately after RFA, and at 12 weeks, using an ordinal scale. Pathological results and neointima formation at the neck were compared using a semiquantitative grading scale. RESULTS Bipolar RFA was able to reliably target the aneurysm neck when the coil mass and stent were used as electrodes. RFA improved angiographic results immediately after partial coiling (p = 0.0024). Two RFA-related complications occurred, involving transient occlusion of 1 carotid artery and 1 hemorrhage from an adventitial arterial blister. At 12 weeks, angiographic results were improved with RFA (median score of 0), when compared with controls (median score of 2; p = 0.0013). Neointimal closure of the aneurysm neck was better with RFA compared with controls (p = 0.0003). CONCLUSIONS Bipolar RFA can improve results of embolization in experimental models by selectively ablating residual lesions after coil embolization.

BACKGROUND AND PURPOSE: Patients treated with coiling are often followed by MR angiography. Our objective was to assess the inter- and intraobserver agreement in diagnosing aneurysm remnants and recurrences by using multimodality imaging, including TOF MRA. MATERIALS AND METHODS: A portfolio composed of 120 selected images from 56 patients was sent to 15 neuroradiologists from 10 institutions. For each case, raters were asked to classify angiographic results (3 classes) of 2 studies (32 MRA-MRA and 24 DSA-MRA pairs) and to provide a final judgment regarding the presence of a recurrence (no, minor, major). Six raters were asked to independently review the portfolio twice. A second study, restricted to 4 raters having full access to all images, was designed to validate the results of the electronic survey. RESULTS: The proportion of cases judged to have a major recurrence varied between 16.1% and 71.4% (mean, 35.0% ± 12.7%). There was moderate agreement overall (κ = 0.474 ± 0.009), increasing to nearly substantial (κ = 0.581 ± 0.014) when the judgment was dichotomized (presence or absence of a major recurrence). Agreement on cases followed-up by MRA-MRA was similarly substantial (κ = 0.601 ± 0.018). The intrarater agreement varied between fair (κ = 0.257 ± 0.093) and substantial (κ= 0.699 ± 0.084), improving with a dichotomized judgment concerning MRA-MRA comparisons. Agreement was no better when raters had access to all images. CONCLUSIONS: There is an important variability in the assessment of angiographic outcomes of endovascular treatments. Agreement on the presence of a major recurrence when comparing 2 MRA studies or the MRA with the last catheter angiographic study can be substantial.