To design a fast and accurate semi-automated segmentation method for spinal cord 3T MR images and to construct a template of the cervical spinal cord.
A semi-automated double threshold-based method ...(DTbM) was proposed enabling both cross-sectional and volumetric measures from 3D T2-weighted turbo spin echo MR scans of the spinal cord at 3T. Eighty-two healthy subjects, 10 patients with amyotrophic lateral sclerosis, 10 with spinal muscular atrophy and 10 with spinal cord injuries were studied. DTbM was compared with active surface method (ASM), threshold-based method (TbM) and manual outlining (ground truth). Accuracy of segmentations was scored visually by a radiologist in cervical and thoracic cord regions. Accuracy was also quantified at the cervical and thoracic levels as well as at C2 vertebral level. To construct a cervical template from healthy subjects' images (n=59), a standardization pipeline was designed leading to well-centered straight spinal cord images and accurate probability tissue map.
Visual scoring showed better performance for DTbM than for ASM. Mean Dice similarity coefficient (DSC) was 95.71% for DTbM and 90.78% for ASM at the cervical level and 94.27% for DTbM and 89.93% for ASM at the thoracic level. Finally, at C2 vertebral level, mean DSC was 97.98% for DTbM compared with 98.02% for TbM and 96.76% for ASM. DTbM showed similar accuracy compared with TbM, but with the advantage of limited manual interaction.
A semi-automated segmentation method with limited manual intervention was introduced and validated on 3T images, enabling the construction of a cervical spinal cord template.
Stapes surgery for otosclerosis can be challenging if access to the oval window niche is restricted. The aim of this study was to determine the accuracy of the computed tomographic (CT) scan in the ...evaluation of anatomical distances, and to analyze its reliability in predicting surgical technical difficulties.
A total of 96 patients (101 ears) were enrolled in a prospective study between 2012 and May 2015. During surgery, we evaluated the distance D1 between the stapes and the facial nerve, distance D2 between the promontory and the facial nerve after ablation of the superstructure, and the intraoperative discomfort of the surgeon. On preoperative CT scans, we measured the width and depth of the oval window niche, and the angle formed by two axes starting from the center-point of the footplate, the first tangential to the superior wall of the promontory, and the second tangential to the inferior wall of the fallopian canal.
Intraoperative distances D1 and D2 were correlated with the width of the oval window and with the facial-promontory angle measured on imaging. CT scan measurements of the facial-promontory angle and width of the oval window were associated with the degree of discomfort of the surgeon. The cut-off threshold for intraoperative subjective discomfort was computed as 1.1 mm for the width of the oval window niche, with a sensibility of 71% and a specificity of 84%.
Preoperative imaging analysis of the oval window width and the facialpromontory angle can predict operative difficulty in otosclerosis surgery.
Abstract We report a case of posterior reversible encephalopathy syndrome (PRES) in which followed-up MRI demonstrated a transient reduction in venous signal on initial SWAN images. The progressive ...normalization of venous signal on D10 and D40 imaging paralleled the progressive decrease of hyperperfusion on CBF images. Decreased venous susceptibility has never been reported in PRES; it relates most likely to a transient BOLD effect induced by brain hyperperfusion.
Posterior reversible encephalopathy syndrome (PRES) is a radioclinical entity associating nonspecific neurological symptoms (headache, seizures, impairment of alertness, visual disturbances…) ...occurring in evocative clinical condition (hypertension, eclampsia, immunosuppressor agents, systemic lupus erythematosus…). In the acute stage, the typical imaging finding is a vasogenic edema predominant in the subcortical parietal-occipital white matter.
The purpose of this pictorial review is to illustrate the different neuroimaging features of PRES and present key radiological elements to assert diagnosis. In this overview, we examine the following points: the distributions of vasogenic edema, hemorrhage, the varying patterns in diffusion and perfusion, the different types of enhancement encountered and the vascular modifications demonstrated by angiography. The cause of PRES is still unknown. Nevertheless, catheter angiography, MR angiography and MR perfusion features in PRES render further insight into its pathophysiology.
Follow-up imaging shows evidence of radiologic improvement in the very large majority of cases in 1 or 2weeks, sometimes in up to 1month. Recurrent PRES attacks are uncommon.
Atypical imaging presentation should not reject the diagnosis of PRES in a compatible clinical situation.
•MRI is an efficient tool for early diagnosis and follow-up in PRES.•Hemorrhage is a common complication.•Decrease in ADC values does not always correlate with nonreversibility of the lesions.•Perfusion MR imaging can demonstrate increased or decreased perfusion.•Multifocal cerebral vasoconstriction is commonly observed.
Neurofibromatosis type 2 (NF2) is a genetic disorder with bilateral vestibular schwannomas (VS) as the most frequent manifestation. Merlin, the
NF2
tumor suppressor, was identified as a negative ...regulator of mammalian target of rapamycin complex 1. Pre-clinical data in mice showed that mTORC1 inhibition delayed growth of NF2-schwannomas. We conducted a prospective single-institution open-label phase II study to evaluate the effects of everolimus in ten NF2 patients with progressive VS. Drug activity was monitored every 3 months. Everolimus was administered orally for 12 months and, if the decrease in tumor volume was >20 % from baseline, treatment was continued for 12 additional months. Other patients stopped when completed 12 months of everolimus but were allowed to resume treatment when VS volume was >20 % during 1 year follow-up. Nine patients were evaluable. Safety was evaluated using CTCAE 3.0 criteria. After 12 months of everolimus, no reduction in volume ≥20 % was observed. Four patients had progressive disease, and five patients had stable disease with a median annual growth rate decreasing from 67 %/year before treatment to 0.5 %/year during treatment. In these patients, tumor growth resumed within 3–6 months after treatment discontinuation. Everolimus was then reintroduced and VS decreased by a median 6.8 % at 24 months. Time to tumor progression increased threefold from 4.2 months before treatment to > 12 months. Hearing was stable under treatment. The safety of everolimus was manageable. Although the primary endpoint was not reached, further studies are required to confirm the potential for stabilization of everolimus.
To calculate the prevalence of sinonasal and ear involvement in an Erdheim-Chester disease (ECD) population, to describe the different ear, nose and throat (ENT) manifestations and to study the ...association between ENT involvement, other organ involvement, and BRAF mutations. We led a retrospective monocentric study in the national referral center for ECD. One hundred and sixty-two patients with ECD and ENT data were included between January 1, 1980 and December 31, 2020. Ear and nose clinical and radiological findings were noted. We described and studied the prevalence of ENT involvement in ECD population. The association between sinonasal and ear involvement, other organ involvement, and BRAF mutations was calculated. The prevalence of ENT manifestations is around 45%. No clinical rhinologic or otologic signs were specific to ECD. Sinus imaging was abnormal in 70% of cases. A bilateral maxillary sinus frame osteosclerosis was highly specific of ECD. Associations were found between the sinus MRI imaging type and BRAF status, central nervous system involvement, cerebellum involvement and xanthelasma. Sinonasal or ear involvement is frequent in ECD and has specific imaging features for sinuses. Trial registration: #2011-A00447-34.
Les sinusites peuvent se révéler par un syndrome du sinus caverneux avec thrombose veineuse sur un tableau clinique bruyant. Exceptionnellement, la présentation est celle d’une atteinte artérielle ...carotidienne interne (ACI).
Un patient de 67 ans, greffé cardiaque en 2019, est hospitalisé initialement pour bilan d’une occlusion carotidienne. Son histoire a commencé il y a deux mois par trois déficits transitoires du bras droit ayant fait découvrir 3 accidents ischémiques punctiformes avec sténose du siphon carotidien droit de bilan étiologique négatif.
Un mois après son hospitalisation, il rapporte des douleurs périorbitaires droites. Une nouvelle ARM retrouve une occlusion complète du siphon carotidien droit avec un faux anévrisme thrombosé faisant saillie dans le sinus sphénoïdal. L’angioscanner cérébral corrobore ces images et montre une sinusite sphénoïdale avec lyse de la paroi en regard du sinus caverneux droit. Le patient est réhospitalisé pour prélèvements infectieux sanguins qui se révèlent tous négatifs, motivant alors un prélèvement chirurgical du sinus qui révèle une greffe aspergillaire.
On retient alors le diagnostic sinusite sphénoïdale aspergillaire ostéolytique, compliqué d’une infection du sinus caverneux avec atteinte artérielle, veineuse et du V. L’atteinte artérielle aura chez ce patient révélé ce syndrome. Le patient est traité par voriconazole pour une durée de 12 mois, ainsi que par aspirine.
D’une part, sur le diagnostic, les sinusites sphénoïdales infectieuses se révèlent plus volontiers par une thrombophlébite du sinus caverneux que par une occlusion de la carotide interne. D’autre part, sur la thérapeutique, nous n’avons pas mis en route de traitement anticoagulant en raison du risque de reperméabilisation et de rupture du faux anévrisme.
Nous avons privilégié une attitude expectative vs traitement endovasculaire avec scanner de contrôle itératif à distance, en espérant que le développement d’une fibrose protège le faux anévrisme d’une recanalisation.
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