Perfusion CT for head and neck tumors: pilot study

BACKGROUND AND PURPOSE: Differentiation of malignant from benign head and neck lesions is often very difficult on imaging studies, especially in patients with treated cancer. We evaluated the feasibility and reproducibility of perfusion CT (CTP) after enhanced head and neck CT and attempted to differentiate benign from malignant processes. METHODS: CTP was attempted in 17 patients after head and neck contrast-enhanced CT. Data were postprocessed by using deconvolution-based perfusion analysis. Ipsilateral and contralateral internal, external, and common carotid arteries were used as arterial input vessels. Postprocessing-generated maps showed mean transit time (MTT), blood volume, blood flow, and capillary permeability surface product. Two readers independently placed regions of interest through the primary site, salivary glands, thyroid gland, paraspinous muscles, muscles of mastication, sternocleidomastoid muscle, base of tongue, and subcutaneous fat. One reader repeated the measurements on separate dates. Data were statistically analyzed, and histologic specimens were obtained. RESULTS: CTP was not possible in four patients, and one was lost to follow-up. Of the remaining 12, five had cancer, and seven had benign processes. We found no significant interreader or intrareader differences and no significant difference between various input vessels. Differentiation between malignant and nonmalignant lesions was most reliable by using MTTs. Measurements were comparable to those in the literature. CONCLUSION: CTP after enhanced head and neck CT is feasible, except perhaps at the laryngeal level. It appears to be reader independent and reproducible regardless of the input vessel. CTP shows promise in distinguishing benign and malignant processes, primarily by means of MTTs.     

Transient traumatic spinal venous hypertensive myelopathy

We present a case of a reversible spinal venous hypertensive myelopathy that occurred following a traumatic mediastinal hematoma. The mediastinal hematoma caused compression of the brachiocephalic vein, resulting in elevation of the venous pressures that ultimately resulted in dilation of the epidural venous plexus and spinal cord edema. The secondary neurologic deficits were the culmination of venous outflow obstruction at the level of the spinal cord that resolved on the resolution of the mediastinal hematoma.     

Radioactivity monitoring of steel processing in Croatian steel mills and foundries

The last twenty years have seen a number of cases of radioactive pollution in metallurgical industry. Therefore many metal producers have implemented systematic monitoring of radioactivity in their production processes, especially in steel processing, steel being the most applied construction material with the annual world output of over billion tonnes. Learning from the experience of the best known steel producers in Europe and the world Croatian steel mills have introduced radioactivity surveillance and control systems for radioactive elements in steel scrap, semi-finished and finished products. This paper argues in favour of radioactivity surveillance and control systems in steel and steel castings production in Croatia, and describes current systems and solutions available. Since we lack our own standards and regulations to control both domestic and imported steel scrap, semi-finished products (crude steel, hot and cold rolled strip) and finished products, we need to start implementing radioactivity surveillance and control systems in our steel and steel castings production applying the current international recommendations and guidelines, until we build up our own monitoring system and adopt legislation on the national level. This paper gives an overview of the basic types of radioactivity surveillance and control systems, the most frequent requirements to be met, as well as of the measurement and information flow in their application in steel and steel castings production.     

The standard mouse assay of anti-venom quality does not measure antibodies neutralising the haemorrhagic activity of Vipera ammodytes venom

The venom of Vipera ammodytes ammodytes (Vaa), like the venoms of other Viperinae snakes, is largely haemorrhagic and necrotising, and only to a lesser extent neurotoxic to humans. The components most extensively studied so far, and most probably involved in generating the observed pathologies, are haemorrhagins (H), members of the metalloproteinase group of enzymes, and neurotoxic ammodytoxins (Atxs), that belong to the secretory phospholipases A2. Rabbit antisera were prepared containing functional antibodies specific for each class of pathology-inducing venom constituents and for both classes together. The involvement of these antibodies in neutralising the toxicity of whole Vaa venom was assessed using the ED50 assay in mice. This assay is the only regulatorily approved assay for estimating anti-venom potency and as such has the task to quantify the active compound neutralising venom-induced pathology of the anti-venom. Fully functional anti-Atx antibodies were shown to be responsible for neutralising the portion of venom toxicity, while anti-H antibodies were not protective in this assay. Thus, the mouse ED50 assay, intended to measure the active principle of the anti-venom, does not measure antibodies specific for Vaa venom haemorrhagins, and consequently does not fulfil its primary task from the regulatory point of view.     

Glioneuronal tumor with neuropil-like islands of the spinal cord with diffuse leptomeningeal neuraxis dissemination

A 54-year-old Caucasian female presented with a 1 year history of intermittent numbness of the left leg progressing to bilateral, lower extremity sensory loss that advanced to include impaired vibration and proprioception. The subsequent thoracic spine magnetic resonance imaging (MRI) scan revealed a heterogeneous, avidly enhancing, centrally situated spinal cord mass involving T7 through T10 in association with thick linear enhancement of the anterior and posterior cord surfaces extending both superiorly and inferiorly. Both the cervical and lumbar spine MRI demonstrated diffuse leptomeningeal disease as well. A brain MRI revealed focal leptomeningeal enhancement in the left and right sylvian fissures, the suprasellar cistern, and the posterior fossa; a pattern consistent with metastatic disease. The patient underwent a T6–T10 laminectomy for tumor biopsy and debulking. Histology revealed a WHO grade III glioneuronal tumor with rosetted neuropil-like islands. Synaptophysin and neurofilament (NF) positive staining was noted within the neural appearing component, whereas, glial fibrillary acidic protein (GFAP) immunopositivity was evident in the fibrillary astrocytoma component of the tumor. The Ki-67 labeling index was 7%. This tumor pattern, now included in the 2007 World Health Organization (WHO) classification of central nervous system tumours as a pattern variation of anaplastic astrocytoma (Kleihues et al. In: Louis et al. (eds) WHO classification of tumours of the central nervous system, 2007), was first described in a four-case series by Teo et al. in 1999. The majority of subsequently reported cases described them as primary tumors of the cerebrum. Herein, we report a unique example of a spinal glioneuronal tumor with neuropil-like islands with associated leptomeningeal dissemination involving the entire craniospinal axis.