Osteoid osteoma and osteoid osteoma-mimicking lesions: biopsy findings, distinctive MDCT features and treatment by radiofrequency ablation.

OBJECTIVE: To report the biopsy findings of osteoid osteoma (OO) and OO-mimicking lesions, assess their distinctive multidetector computed tomography (MDCT) features and evaluate treatment by radiofrequency ablation (RFA). METHODS: In this multicentric retrospective study, 80 patients (54 male, 26 female, mean age 24.1 years, range 5-48) with presumed (clinical and MDCT features) OO were treated by percutaneous RFA between May 2002 and June 2009. Per-procedural biopsies were always performed. The following MDCT features were assessed: skeletal distribution and location within the bone, size, central calcification, surrounding osteosclerosis and periosteal reaction. Clinical success of RFA was evaluated. RESULTS: Histopathological diagnoses were: 54 inconclusive biopsies, 16 OO, 10 OO-mimicking lesions (5 chronic osteomyelitis, 3 chondroblastoma, 1 eosinophilic granuloma, 1 fibrous dysplasia). OO-mimicking lesions were significantly greater in size (p = 0.001) and presented non-significant trends towards medullary location (p = 0.246), moderate surrounding osteosclerosis (p = 0.189) and less periosteal reaction (p = 0.197), compared with OO. Primary success for ablation of OO-mimicking lesions was 100% at 1 month, 85.7% at 6 and 12 months, and 66.7% at 24 months. Secondary success was 100%. CONCLUSION: Larger size, medullary location, less surrounding osteosclerosis and periosteal reaction on MDCT may help differentiate OO-mimicking lesions from OO. OO-mimicking lesions are safely and successfully treated by RFA.

Morphometric Vertebral Assessments via the Use of Dual X-ray Absorptiometry for the Evaluation of Radiographic Damage in Ankylosing Spondylitis: A Pilot Study.

We performed a pilot study to compare vertebral fracture assessments (VFA) and lateral X-rays in terms of inter- and intraobserver reliability and degree of correlation for the detection of syndesmophytes in ankylosing spondylitis (AS). We recruited 19 patients with AS and recent lumbar or cervical lateral X-rays with at least one syndesmophyte. Each patient underwent dual-energy X-ray absorptiometry with measurement of bone mineral density and dorso-lumbar VFA. Intra- and interreader reliability for VFA and X-rays were measured using 2 independent, blinded observers and Cohen's kappa values. An adapted modified Stoke Ankylosing Spondylitis Spinal Score (amSASSS) was generated with each method, and these 2 values correlated. For X-rays, intraobserver and interobserver agreement were 94.3% (κ = 0.83) and 98.6% (κ = 0.96), respectively; for VFA, corresponding values were 92.8% (κ = 0.79) and 93.8% (κ = 0.82). Overall agreement between the 2 techniques was 88.6% (κ = 0.72). The Pearson correlation coefficient for the 2 methods was 0.95 for the modified Stoke Ankylosing Spondylitis Spinal Score . Per dual-energy X-ray absorptiometry-generated bone mineral density, >50% of patients were osteopenic and 10% osteoporotic. In terms of reproducibility and correlation with X-rays, performing a VFA appears to be a candidate for assessing radiographic damage in AS, thought further research is necessary to justify this indication.

Phase Contrast X-Ray Tomographic Microscopy for Biological and Materials Science Applications

The application of two approaches for high-throughput, high-resolution X-ray phase contrast tomographic imaging being used at the tomographic microscopy and coherent radiology experiments (TOMCAT) beamline of the SLS is discussed and illustrated. Differential phase contrast (DPC) imaging, using a grating interferometer and a phase-stepping technique, is integrated into the beamline environment at TOMCAT in terms of the fast acquisition and reconstruction of data and the availability to scan samples within an aqueous environment. A second phase contrast method is a modified transfer of intensity approach that can yield the 3D distribution of the decrement of the refractive index of a weakly absorbing object from a single tomographic dataset. The two methods are complementary to one another: the DPC method is characterised by a higher sensitivity and by moderate resolution with larger samples; the modified transfer of intensity approach is particularly suited for small specimens when high resolution (around 1 mu m) is required. Both are being applied to investigations in the biological and materials science fields.

X-ray microtomography of Larger Foraminifera

X-ray microtomography has become a new tool in earth sciences to obtain non-destructive 3D-image data from geological objects in which variations in mineralogy, chemical composition and/or porosity create sufficient x-ray density contrasts.We present here first, preliminary results of an application to the external and internal morphology of Permian to Recent Larger Foraminifera. We use a SkyScan-1072 high-resolution desk-top micro-CT system. The system has a conical x-ray source with a spot size of about 5µm that runs at 20-100kV, 0-250µA, resulting in a maximal resolution of 5µm. X-ray transmission images are captured by a scintillator coupled via fibre optics to a 1024x1024 pixel 12-bit CCD. The object is placed between the x-ray source and the scintillator on a stub that rotates 360°around its vertical axis in steps as small as 0.24 degrees. Sample size is limited to 2 cm due to the absorption of geologic material for x-rays. The transmission images are back projected using a Feldkamp algorithm into a vertical stack of up to 1000 1Kx1K images that represent horizontal cuts of the object. This calculation takes 2 to several hours on a Double-Processor 2.4GHz PC. The stack of images (.bmp) can be visualized with any 3D-imaging software, used to produce cuts of Larger Foraminifera. Among other applications, the 3D-imaging software furnished by SkyScan can produce 3D-models by defining a threshold density value to distinguish "solid" from "void. Several models with variable threshold values and colors can be imbricated, rotated and cut together. The best results were obtained with microfossils devoid of chamber-filling cements (Permian, Eocene, Recent). However, even slight differences in cement mineralogy/composition can result in surprisingly good x-ray density contrasts.X-ray microtomography may develop into a powerful tool for larger microfossils with a complex internal structure, because it is non-destructive, requires no preparation of the specimens, and produces a true 3D-image data set. We will use these data sets in the future to produce cuts in any direction to compare them with arbitrary cuts of complex microfossils in thin sections. Many groups of benthic and planktonic foraminifera may become more easily determinable in thin section by this way.

Cardiac CT: practical approach to integrate appropriate indications in daily practice.

Recent advances in CT technologies had significantly improved the clinical utility of cardiac CT. Major efforts have been made to optimize the image quality, standardize protocols and limit the radiation exposure. Rapid progress in post-processing tools dedicated not only to the coronary artery assessment but also to the cardiac cavities, valves and veins extended applications of cardiac CT. This potential might be however used optimally considering the current appropriate indications for use as well as the current technical imitations. Coronary artery disease and related ischemic cardiomyopathy remain the major applications of cardiac CT and at the same time the most complex one. Integration of a specific knowledge is mandatory for optimal use in this area for asymptomatic as for symptomatic patients, with a specific regards to patient with acute chest pain. This review aimed to propose a practical approach to implement appropriate indications in our routine practice. Emerging indications and future direction are also discussed. Adequate preparation of the patient, training of physicians, and the multidisciplinary interaction between actors are the key of successful implementation of cardiac CT in daily practice.

Therapy of acute massive pulmonary embolism associated with Klippel-Trenaunay syndrome.

Acute massive pulmonary embolism (PE) is a life-threatening event. Before the era of cardiopulmonary bypass, acute pulmonary embolectomy had been historically attempted in patients with severe hemodynamic compromise. The Klippel-Trenaunay syndrome (KTS) represents a significant life-long risk for major thromboembolic events. We present two young patients with Klippel-Trenaunay syndrome who survived surgical embolectomy after massive PE and cardiopulmonary resuscitation, with good postoperative recovery. Even though the role of surgical embolectomy in massive PE is not clearly defined, with current technology it can be life saving and can lead to a complete recovery, especially in young patients as described in this study.

Extent of hypoattenuation on CT angiography source images in basilar artery occlusion: prognostic value in the Basilar Artery International Cooperation Study.

BACKGROUND AND PURPOSE: The posterior circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS) quantifies the extent of early ischemic changes in the posterior circulation with a 10-point grading system. We hypothesized that pc-ASPECTS applied to CT angiography source images predicts functional outcome of patients in the Basilar Artery International Cooperation Study (BASICS). METHODS: BASICS was a prospective, observational registry of consecutive patients with acute symptomatic basilar artery occlusion. Functional outcome was assessed at 1 month. We applied pc-ASPECTS to CT angiography source images of patients with CT angiography for confirmation of basilar artery occlusion. We calculated unadjusted and adjusted risk ratios (RRs) of pc-ASPECTS dichotomized at ≥8 versus <8. Primary outcome measure was favorable outcome (modified Rankin Scale scores 0-3). Secondary outcome measures were mortality and functional independence (modified Rankin Scale scores 0-2). RESULTS: Of 158 patients included, 78 patients had a CT angiography source images pc-ASPECTS≥8. Patients with a pc-ASPECTS≥8 more often had a favorable outcome than patients with a pc-ASPECTS<8 (crude RR, 1.7; 95% CI, 0.98-3.0). After adjustment for age, baseline National Institutes of Health Stroke Scale score, and thrombolysis, pc-ASPECTS≥8 was not related to favorable outcome (RR, 1.3; 95% CI, 0.8-2.2), but it was related to reduced mortality (RR, 0.7; 95% CI, 0.5-0.98) and functional independence (RR, 2.0; 95% CI, 1.1-3.8). In post hoc analysis, pc-ASPECTS dichotomized at ≥6 versus <6 predicted a favorable outcome (adjusted RR, 3.1; 95% CI, 1.2-7.5). CONCLUSIONS: pc-ASPECTS on CT angiography source images independently predicted death and functional independence at 1 month in the CT angiography subgroup of patients in the BASICS registry.

Melan-A-specific cytotoxic T cells are associated with tumor regression and autoimmunity following treatment with anti-CTLA-4.

PURPOSE: Ipilimumab is a monoclonal antibody that blocks the immune-inhibitory interaction between CTL antigen 4 (CTLA-4) and its ligands on T cells. Clinical trials in cancer patients with ipilimumab have shown promising antitumor activity, particularly in patients with advanced melanoma. Often, tumor regressions in these patients are correlated with immune-related side effects such as dermatitis, enterocolitis, and hypophysitis. Although these reactions are believed to be immune-mediated, the antigenic targets for the cellular or humoral immune response are not known. EXPERIMENTAL DESIGN: We enrolled patients with advanced melanoma in a phase II study with ipilimumab. One of these patients experienced a complete remission of his tumor. The specificity and functional properties of CD8-positive T cells in his peripheral blood, in regressing tumor tissue, and at the site of an immune-mediated skin rash were investigated. RESULTS: Regressing tumor tissue was infiltrated with CD8-positive T cells, a high proportion of which were specific for Melan-A. The skin rash was similarly infiltrated with Melan-A-specific CD8-positive T cells, and a dramatic (>30-fold) increase in Melan-A-specific CD8-positive T cells was apparent in peripheral blood. These cells had an effector phenotype and lysed Melan-A-expressing tumor cells. CONCLUSIONS: Our results show that Melan-A may be a major target for both the autoimmune and antitumor reactions in patients treated with anti-CTLA-4, and describe for the first time the antigen specificity of CD8-positive T cells that mediate tumor rejection in a patient undergoing treatment with an anti-CTLA-4 antibody. These findings may allow a better integration of ipilimumab into other forms of immunotherapy.

Anterior ischemic optic neuropathy in eyes with optic disc drusen.

BACKGROUND: There have been anecdotal reports of anterior ischemic optic neuropathy (AION) occurring in eyes with optic disc drusen (ODD), but the clinical features of this condition have not been well characterized. OBJECTIVES: To better describe the clinical features of AION associated with ODD and to compare the clinical features of this condition with those of "garden variety" nonarteritic AION. METHODS: We reviewed the medical records of 20 patients who experienced an episode of AION in an eye with ODD. In 4 patients, both eyes were affected; thus, 24 eyes were studied. The diagnosis of ODD was made by ophthalmoscopic identification, orbital ultrasonography, or computed tomographic scanning. We recorded age, sex, vascular risk factors, symptoms, visual acuity, visual fields, and results of the follow-up examination in all patients. These findings were compared with data from previously reported series of patients with nonarteritic AION. RESULTS: Our 20 patients included 14 men and 6 women (age range, 18-69 years; mean, 49.4 years). Vascular risk factors were identified in 10 patients (50%). Three patients reported episodes of transient visual loss before their fixed deficit. The visual acuity at the initial examination was 20/60 or better in 15 (62%) of the 24 eyes; 8 had a visual acuity of 20/20. The predominant pattern of visual field loss was an altitudinal or arcuate defect in 19 (79%) and a centrocecal scotoma in 5 (21%) of the 24 eyes. There was subjective worsening of vision before the initial neuro-ophthalmic examination in 11 eyes (46%) and objective documentation of progression in 7 eyes (29%). The final visual acuity was 20/40 or better in 13 (62%) of 21 eyes and 20/200 or worse in 3 (14%) of 21 eyes. CONCLUSIONS: Our patients were strikingly similar to those with nonarteritic AION unassociated with drusen in regard to prevalence of vascular risk factors, pattern of visual field loss, and occurrence of a subsequent similar event in the fellow eye. In contrast, however, patients with ODD-AION were younger than those with nonarteritic AION, were more likely to report preceding episodes of transient visual obscuration, and enjoyed a more favorable visual outcome.

Arteriovenous malformation in meningothelial meningioma: case report.

An unusual association of a meningioma and an arteriovenous malformation is reported. A 68-year-old man developed left homonymous hemianopsia, left hemiparesis, and gaze palsy. Magnetic resonance imaging showed a right occipital mass lesion containing multiple signal-void areas with tubular and honeycomb appearance, suggesting a marked vascular component. An angiogram showed abnormal vasculature in the mass supplied by the posterior cerebral artery and a dural arteriovenous malformation on the tentorium. Neuropathological examination after total removal of the mass revealed a meningothelial meningioma including major portions of an arteriovenous malformation that extended from the dura and leptomeninges, through the meningioma, and into the occipital lobe, where the tumor was located.

Brain dysfunction in sepsis: what can we learn from cerebral perfusion studies?

Investigations on the relationship between sepsis, brain dysfunction, and cerebral perfusion are methodologically very difficult to perform. It is important to interpret the results of such studies in view of our limited ability to diagnose and quantify brain dysfunction and to consider our limited understanding of the mechanisms that lead to or are associated with brain dysfunction in sepsis.

Ascending aorta measurements as assessed by ECG-gated multi-detector computed tomography : a pilot study to etablish normative values for transcatheters therapies

Rapport de synthèse : Mesures de l'aorte ascendante par scanner synchronisé au rythme cardiaque: une étude pilote pour établir des valeurs normatives dans le cadre des futures thérapies par transcathéter. Objectif : L'objectif de cette étude est d'établir les valeurs morphométriques normatives de l'aorte ascendante à l'aide de l'angiographie par scanner synchronisé au rythme cardiaque, afin d'aider au développement des futurs traitements par transcathéter. Matériels et méthodes : Chez soixante-dix-sept patients (âgé de 22 à 83 ans, âge moyen: 54,7 ans), une angiographie par scanner synchronisé au rythme cardiaque a été réalisée pour évaluation des vaisseaux coronaires. Les examens ont été revus afin d'étudier l'anatomie de la chambre de chasse du ventricule gauche jusqu'au tronc brachio-céphalique droit. A l'aide de programmes de reconstructions multiplanaires et de segmentation automatique, différents diamètres et longueurs considérés comme importants pour les futurs traitements par transcathéter ont été mesurés. Les valeurs sont exprimées en moyennes, médianes, maximums, minimums, écart-types et en coefficients de variation. Les variations de diamètre de l'aorte ascendante durant le cycle cardiaque ont été aussi considérées. Résultats : Le diamètre moyen de la chambre de chasse du ventricule gauche était de 20.3+/-3.4 mm. Au niveau du sinus coronaire de l'aorte, il était de 34.2+/-4.1 mm et au niveau de la jonction sinotubulaire il était de 29.7+/-3.4 mm. Le diamètre moyen de l'aorte ascendante était de 32.7+/-3.8 mm. Le coefficient de variation de ces mesures variait de 12 à 17%. La distance moyenne entre l'insertion proximale des valvules aortiques et le départ du tronc brachio-céphalique droit était de 92.6+/-11.8 mm. La distance moyenne entre l'insertion proximale des valvules aortiques et l'origine de l'artère coronaire proximale était de 12.1+/-3.7 mm avec un coefficient de variation de 31%. La distance moyenne entre les deux ostia coronaires était de 7.2+/-3.1 mm avec un coefficient de variation de 43%. La longueur moyenne du petit arc de l'aorte ascendante entre l'artère coronaire gauche et le tronc brachio-céphalique droit était de 52.9+/-9.5 mm. La longueur moyenne de la continuité fibreuse entre la valve aortique et la valvule mitrale antérieure était de 14.6+/-3.3 mm avec un coefficient de variation de 23%. L'aire moyenne de la valve aortique était de 582.0+/-131.9 mm2. La variation du diamètre antéro-postérieur et transverse de l'aorte ascendante était respectivement de 8.4% et de 7.3%. Conclusion Il existe d'importantes variations inter-individuelles dans les mesures de l'aorte ascendante avec cependant des variations intra-individuelles faibles durant le cycle cardiaque. De ce fait, une approche personnalisée pour chaque patient est recommandée dans la confection des futures endoprothèses de l'aorte ascendante. Le scanner synchronisé au rythme cardiaque jouera un rôle prépondérant dans le bilan préthérapeutique. Abstract : The aim of this study was to provide an insight into normative values of the ascending aorta in regards to novel endovascular procedures using ECG-gated multi-detector CT angiography. Seventy-seven adult patients without ascending aortic abnormalities were evaluated. Measurements at relevant levels of the aortic root and ascending aorta were obtained. Diameter variations of the ascending aorta during cardiac cycle were also considered. Mean diameters (mm) were as follows: LV outflow tract 20.3+/-3.4, coronary sinus 34.2+/-4.1, sinotubular junction 29.7+-3.4 and mid ascending aorta 32.7+/-3.8 with coefficients of variation (CV) ranging from 12 to 17%. Mean distances (mm) were: from the plane passing through the proximal insertions of the aortic valve cusps to the right brachio-cephalic artery (BCA) 92.6111.8, from the plane passing through the proximal insertions of the aortic valve cusps to the proximal coronary ostium 12.1+/-3.7, and between both coronary ostia 7.2+/-3.1, minimal arc of the ascending aorta from left coronary ostium to right BCA 52.9 X9.5, and the fibrous continuity between the aortic valve and the anterior leaflet of the mitral valve 14.óf3.3, CV 13-43%. Mean aortic valve area was 582+-131.9 mm2. The variations of the antero-posterior and transverse diameters of the ascending aorta during the cardiac cycle were 8.4% and 7.3%, respectively. Results showed large inter-individual variations in diameters and distances but with limited intra-individual variations during the cardiac cycle. A personalized approach for planning endovascular devices must be considered.

Papilledema and obstructive sleep apnea syndrome.

OBJECTIVES: To characterize the pathogenesis and clinical features of optic disc edema associated with obstructive sleep apnea syndrome (SAS). METHODS: A series of 4 patients with SAS and papilledema (PE) underwent complete neuro-ophthalmologic evaluation and lumbar puncture. In 1 patient, continuous 24-hour intracranial pressure (ICP) monitoring was also performed. RESULTS: All 4 patients had bilateral PE that was asymmetric in 2. Three patients had optic nerve dysfunction, asymmetric in 1, unilateral in 2. Daytime cerebrospinal fluid pressure measurements were within normal range. Nocturnal monitoring performed in one patient, however, demonstrated repeated episodes of marked ICP elevation associated with apnea and arterial oxygen desaturation. CONCLUSIONS: We propose that PE in SAS is due to episodic nocturnal hypoxemia and hypercarbia resulting in increased ICP secondary to cerebral vasodilation. In these individuals, intermittent ICP elevation is sufficient to cause persistent disc edema. These patients may be at increased risk for developing visual loss secondary to PE compared with patients with obesity-related pseudotumor cerebri because of associated hypoxemia. The diagnosis of SAS PE may not be appreciated because daytime cerebrospinal fluid pressure measurements are normal and because patients tend to present with visual loss rather than with symptoms of increased ICP.